Sample records for atomic shield 1947-1952

  1. Prediction of effective atomic number (Z) for laminated shielding material 

    E-Print Network [OSTI]

    Sarder, Md. Maksudur Rahaman

    1999-01-01T23:59:59.000Z

    (&?/P)=3. 103E-2 (P/P)=5. 951E-2 (P, ?/P)=2. 603 E-2 (&/P)=6. 803E-2 P', ?/P)=3. 654E-2 3. 0 (&/P)=3. 968E-2 (&, ?/P)=2. 281E-2 (4/P)=3. 616E-2 (P, ?/P)=2, 042E 2 (P/P)=4. 200E-2 (&??/P)=2. 322E-2 25 35 30 25 20 N 15 10 ~ffe w ~2fe w ~3... fe w ~4fe w ~5fe w 0 0 4 mfp 10 Fig. 5a. Z?fr for two-layered shields (Zf&Z2) as a function of mfp 90 80 70 4D ~2w pb 3D ~3w pb 20 ~4w pb 10 ~6w pb 0 0 2 4 6 8 1D m fp Fig. 5. b. Z, fr for two-layered shields (Zf&Z2) as a function...

  2. Prediction of effective atomic number (Z) for laminated shielding material

    E-Print Network [OSTI]

    Sarder, Md. Maksudur Rahaman

    1999-01-01T23:59:59.000Z

    (&?/P)=3. 103E-2 (P/P)=5. 951E-2 (P, ?/P)=2. 603 E-2 (&/P)=6. 803E-2 P', ?/P)=3. 654E-2 3. 0 (&/P)=3. 968E-2 (&, ?/P)=2. 281E-2 (4/P)=3. 616E-2 (P, ?/P)=2, 042E 2 (P/P)=4. 200E-2 (&??/P)=2. 322E-2 25 35 30 25 20 N 15 10 ~ffe w ~2fe w ~3... fe w ~4fe w ~5fe w 0 0 4 mfp 10 Fig. 5a. Z?fr for two-layered shields (Zf&Z2) as a function of mfp 90 80 70 4D ~2w pb 3D ~3w pb 20 ~4w pb 10 ~6w pb 0 0 2 4 6 8 1D m fp Fig. 5. b. Z, fr for two-layered shields (Zf&Z2) as a function...

  3. Atom Interferometry in Space: Thermal Management and Magnetic Shielding

    E-Print Network [OSTI]

    Alexander Milke; André Kubelka-Lange; Norman Gürlebeck; Benny Rievers; Sven Herrmann; Thilo Schuldt; Claus Braxmaier

    2014-08-18T23:59:59.000Z

    Atom interferometry is an exciting tool to probe fundamental physics. It is considered especially apt to test the universality of free fall by using two different sorts of atoms. The increasing sensitivity required for this kind of experiment sets severe requirements on its environments, instrument control, and systematic effects. This can partially be mitigated by going to space as was proposed, for example, in the Spacetime Explorer and Quantum Equivalence Principle Space Test (STE-QUEST) mission. However, the requirements on the instrument are still very challenging. For example, the specifications of the STE-QUEST mission imply that the Feshbach coils of the atom interferometer are allowed to change their radius only by about 260 nm or 2.6E-4% due to thermal expansion although they consume an average power of 22 W. Also Earth's magnetic field has to be suppressed by a factor of 10E5. We show in this article that with the right design such thermal and magnetic requirements can indeed be met and that these are not an impediment for the exciting physics possible with atom interferometers in space.

  4. Atom interferometry in space: Thermal management and magnetic shielding

    SciTech Connect (OSTI)

    Milke, Alexander; Kubelka-Lange, André; Gürlebeck, Norman, E-mail: norman.guerlebeck@zarm.uni-bremen.de; Rievers, Benny; Herrmann, Sven [Center of Applied Space Technology and Microgravity (ZARM), University Bremen, Am Fallturm, 28359 Bremen (Germany); Schuldt, Thilo [DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Braxmaier, Claus [Center of Applied Space Technology and Microgravity (ZARM), University Bremen, Am Fallturm, 28359 Bremen (Germany); DLR Institute for Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany)

    2014-08-15T23:59:59.000Z

    Atom interferometry is an exciting tool to probe fundamental physics. It is considered especially apt to test the universality of free fall by using two different sorts of atoms. The increasing sensitivity required for this kind of experiment sets severe requirements on its environments, instrument control, and systematic effects. This can partially be mitigated by going to space as was proposed, for example, in the Spacetime Explorer and Quantum Equivalence Principle Space Test (STE-QUEST) mission. However, the requirements on the instrument are still very challenging. For example, the specifications of the STE-QUEST mission imply that the Feshbach coils of the atom interferometer are allowed to change their radius only by about 260?nm or 2.6 × 10{sup ?4}?% due to thermal expansion although they consume an average power of 22?W. Also Earth's magnetic field has to be suppressed by a factor of 10{sup 5}. We show in this article that with the right design such thermal and magnetic requirements can indeed be met and that these are not an impediment for the exciting physics possible with atom interferometers in space.

  5. A study of form-principles affording shielding from atomic fallout

    E-Print Network [OSTI]

    Lanford, Samuel Taylor

    1963-01-01T23:59:59.000Z

    "). The D.O.D.-O.C.D. program, for the moat part, has placed emphasis on methods of calculating "attenuation", which is a measurement of the reduction of radiation through masses of shielding materials, through distance and other means. The calculations...

  6. Modular shield

    DOE Patents [OSTI]

    Snyder, Keith W. (Sandia Park, NM)

    2002-01-01T23:59:59.000Z

    A modular system for containing projectiles has a sheet of material including at least a polycarbonate layer held by a metal frame having a straight frame member corresponding to each straight edge of the sheet. Each frame member has a U-shaped shield channel covering and holding a straight edge of the sheet and an adjacent U-shaped clamp channel rigidly held against the shield channel. A flexible gasket separates each sheet edge from its respective shield channel; and each frame member is fastened to each adjacent frame member only by clamps extending between adjacent clamp channels.

  7. Thermocouple shield

    DOE Patents [OSTI]

    Ripley, Edward B. (Knoxville, TN)

    2009-11-24T23:59:59.000Z

    A thermocouple shield for use in radio frequency fields. In some embodiments the shield includes an electrically conductive tube that houses a standard thermocouple having a thermocouple junction. The electrically conductive tube protects the thermocouple from damage by an RF (including microwave) field and mitigates erroneous temperature readings due to the microwave or RF field. The thermocouple may be surrounded by a ceramic sheath to further protect the thermocouple. The ceramic sheath is generally formed from a material that is transparent to the wavelength of the microwave or RF energy. The microwave transparency property precludes heating of the ceramic sheath due to microwave coupling, which could affect the accuracy of temperature measurements. The ceramic sheath material is typically an electrically insulating material. The electrically insulative properties of the ceramic sheath help avert electrical arcing, which could damage the thermocouple junction. The electrically conductive tube is generally disposed around the thermocouple junction and disposed around at least a portion of the ceramic sheath. The concepts of the thermocouple shield may be incorporated into an integrated shielded thermocouple assembly.

  8. Shielding vacuum fluctuations with graphene

    E-Print Network [OSTI]

    Sofia Ribeiro; Stefan Scheel

    2014-03-14T23:59:59.000Z

    The Casimir-Polder interaction of ground-state and excited atoms with graphene is investigated with the aim to establish whether graphene systems can be used as a shield for vacuum fluctuations of an underlying substrate. We calculate the zero-temperature Casimir-Polder potential from the reflection coefficients of graphene within the framework of the Dirac model. For both doped and undoped graphene we show limits at which graphene could be used effectively as a shield. Additional results are given for AB-stacked bilayer graphene.

  9. CSR SHIELDING EXPERIMENT

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    triplets are essential elements of CSR shielding experiment beamline setup. e - e - e - BPMflag image HES image Dispersion function minimized in the dipole where shielding plates...

  10. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1985-02-12T23:59:59.000Z

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  11. Magnetic shielding design analysis

    SciTech Connect (OSTI)

    Kerns, J.A.; LaPaz, A.D.; Fabyan, J.

    1983-12-27T23:59:59.000Z

    Two passive magnetic-shielding-design approaches for static external fields are reviewed. The first approach uses the shielding solutions for spheres and cylinders while the second approach requires solving Maxwell's equations. Experimental data taken at LLNL are compared with the results from these shieldings-design methods, and improvements are recommended for the second method. Design considerations are discussed here along with the importance of material gaps in the shield.

  12. INTOR radiation shielding for personnel access

    SciTech Connect (OSTI)

    Gohar, Y.; Abdou, M.

    1981-01-01T23:59:59.000Z

    The INTOR reactor shield system consists of the blanket, bulk shield, penetration shield, component shield, and biological shield. The bulk shield consists of two parts: (a) the inboard shield; and (b) the outboard shield. The distinction between the different components of the shield system is essential to satisfy the different design constraints and achieve various objectives.

  13. Gamma ray detector shield

    DOE Patents [OSTI]

    Ohlinger, R.D.; Humphrey, H.W.

    1985-08-26T23:59:59.000Z

    A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

  14. Hysteresis prediction inside magnetic shields and application

    SciTech Connect (OSTI)

    Mori?, Igor [Observatoire de Paris, SYRTE, Avenue Denfert 77, 75014 Paris (France); CNES, Edouard Belin 18, 31400 Toulouse (France); De Graeve, Charles-Marie [SOGETI High Tech, chemin Laporte 3, 31300 Toulouse (France); Grosjean, Olivier [CNES, Edouard Belin 18, 31400 Toulouse (France); Laurent, Philippe [Observatoire de Paris, SYRTE, Avenue Denfert 77, 75014 Paris (France)

    2014-07-15T23:59:59.000Z

    We have developed a simple model that is able to describe and predict hysteresis behavior inside Mumetal magnetic shields, when the shields are submitted to ultra-low frequency (<0.01 Hz) magnetic perturbations with amplitudes lower than 60??T. This predictive model has been implemented in a software to perform an active compensation system. With this compensation the attenuation of longitudinal magnetic fields is increased by two orders of magnitude. The system is now integrated in the cold atom space clock called PHARAO. The clock will fly onboard the International Space Station in the frame of the ACES space mission.

  15. Adhesive particle shielding

    DOE Patents [OSTI]

    Klebanoff, Leonard Elliott (Dublin, CA); Rader, Daniel John (Albuquerque, NM); Walton, Christopher (Berkeley, CA); Folta, James (Livermore, CA)

    2009-01-06T23:59:59.000Z

    An efficient device for capturing fast moving particles has an adhesive particle shield that includes (i) a mounting panel and (ii) a film that is attached to the mounting panel wherein the outer surface of the film has an adhesive coating disposed thereon to capture particles contacting the outer surface. The shield can be employed to maintain a substantially particle free environment such as in photolithographic systems having critical surfaces, such as wafers, masks, and optics and in the tools used to make these components, that are sensitive to particle contamination. The shield can be portable to be positioned in hard-to-reach areas of a photolithography machine. The adhesive particle shield can incorporate cooling means to attract particles via the thermophoresis effect.

  16. Microscreen radiation shield for thermoelectric generator

    DOE Patents [OSTI]

    Hunt, Thomas K. (Ann Arbor, MI); Novak, Robert F. (Farmington Hills, MI); McBride, James R. (Ypsilanti, MI)

    1990-01-01T23:59:59.000Z

    The present invention provides a microscreen radiation shield which reduces radiative heat losses in thermoelectric generators such as sodium heat engines without reducing the efficiency of operation of such devices. The radiation shield is adapted to be interposed between a reaction zone and a means for condensing an alkali metal vapor in a thermoelectric generator for converting heat energy directly to electrical energy. The radiation shield acts to reflect infrared radiation emanating from the reaction zone back toward the reaction zone while permitting the passage of the alkali metal vapor to the condensing means. The radiation shield includes a woven wire mesh screen or a metal foil having a plurality of orifices formed therein. The orifices in the foil and the spacing between the wires in the mesh is such that radiant heat is reflected back toward the reaction zone in the interior of the generator, while the much smaller diameter alkali metal atoms such as sodium pass directly through the orifices or along the metal surfaces of the shield and through the orifices with little or no impedance.

  17. SHIELD certification package

    SciTech Connect (OSTI)

    Boman, C.

    1992-02-01T23:59:59.000Z

    Certification as applied to existing computer codes includes the verification and validation process, placing the code in configuration control, establishing user qualification standards and training requirements. All software intended for use in critical calculations must be certified. This report is intended to fulfill the requirements for the certification of the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system built February, 1992, by W.S. Parks. These modules are used for burnup, cooling, separate, and edit calculations.

  18. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    2000-12-26T23:59:59.000Z

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  19. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    1998-01-01T23:59:59.000Z

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  20. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, W.J.; Lessing, P.A.

    1998-07-28T23:59:59.000Z

    A composition is disclosed for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm{sup 3} and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile. 5 figs.

  1. Glove box shield

    DOE Patents [OSTI]

    Brackenbush, Larry W. (Richland, WA); Hoenes, Glenn R. (Richland, WA)

    1981-01-01T23:59:59.000Z

    According to the present invention, a shield for a glove box housing radioactive material is comprised of spaced apart clamping members which maintain three overlapping flaps in place therebetween. There is a central flap and two side flaps, the side flaps overlapping at the interior edges thereof and the central flap extending past the intersection of the side flaps in order to insure that the shield is always closed when the user withdraws his hand from the glove box. Lead loaded neoprene rubber is the preferred material for the three flaps, the extent of lead loading depending upon the radiation levels within the glove box.

  2. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC)

    1994-01-01T23:59:59.000Z

    A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

  3. Modified shielding jet model for twin-jet shielding analysis

    E-Print Network [OSTI]

    Gilbride, Jennifer Frances

    1983-01-01T23:59:59.000Z

    MODIFIED SHIELDING JET MODEL FOR TWIN-JET SHIELDING ANALYSIS A Thesis by JENNIFER FRANCES GILBRIDE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1983 Major Subject: Mechanical Engineering MODIFIED SHIELDING JET MODEL FOR TWIN-JET SHIELDING ANALYSIS A Thesis by JENNIFER FRANCES GILBRIDE Approved as to stvle and content by: 'Carl H. Gerhold (Chairman of Committee) J. Craag Dutton...

  4. The Tower Shielding Facility: Its glorious past

    SciTech Connect (OSTI)

    Muckenthaler, F.J.

    1997-05-07T23:59:59.000Z

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.

  5. SUPERCONDUCTING SHIELDING By W. O. HAMILTON,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    41. SUPERCONDUCTING SHIELDING By W. O. HAMILTON, Stanford University, Department of Physics, Stanford, California (U.S.A.). Abstract. 2014 Superconducting shields offer the possibility of obtaining shielding from external time varying fields. Various techniques of superconducting shielding

  6. Review Article RADIATION SHIELDING TECHNOLOGY

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    Review Article RADIATION SHIELDING TECHNOLOGY J. Kenneth Shultis and Richard E. Faw* Abstract Physics Society INTRODUCTION THIS IS a review of the technology of shielding against the effects to the review. The first treats the evolution of radiation-shielding technology from the beginning of the 20th

  7. Gas shielding apparatus

    DOE Patents [OSTI]

    Brandt, D.

    1984-06-05T23:59:59.000Z

    An apparatus for preventing oxidation by uniformly distributing inert shielding gas over the weld area of workpieces such as pipes being welded together. The apparatus comprises a chamber and a gas introduction element. The chamber has an annular top wall, an annular bottom wall, an inner side wall and an outer side wall connecting the top and bottom walls. One side wall is a screen and the other has a portion defining an orifice. The gas introduction element has a portion which encloses the orifice and can be one or more pipes. The gas introduction element is in fluid communication with the chamber and introduces inert shielding gas into the chamber. The inert gas leaves the chamber through the screen side wall and is dispersed evenly over the weld area.

  8. Multilayer radiation shield

    DOE Patents [OSTI]

    Urbahn, John Arthur (Saratoga Springs, NY); Laskaris, Evangelos Trifon (Niskayuna, NY)

    2009-06-16T23:59:59.000Z

    A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

  9. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-08-02T23:59:59.000Z

    A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

  10. DETECTORS, SAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSION TOMOGRAPHY

    E-Print Network [OSTI]

    Derenzo, S.E.

    2010-01-01T23:59:59.000Z

    SAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSIONSAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSIONSAMPLING, SHIELDING, AND ELECTRONICS FOR POSITRON EMISSION

  11. Actively driven thermal radiation shield

    DOE Patents [OSTI]

    Madden, Norman W. (Livermore, CA); Cork, Christopher P. (Pleasant Hill, CA); Becker, John A. (Alameda, CA); Knapp, David A. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

  12. Radiation Shielding for Fusion Reactors

    SciTech Connect (OSTI)

    Santoro, R.T.

    1999-10-01T23:59:59.000Z

    Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel. Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shielding. Radiation transport calculations are essential for predicting and confirming the nuclear performance of the reactor and, as such, must be an essential part of the reactor design process. Development and optimization of reactor components from the first wall and primary shielding to the penetrations and containment shielding must be carried out in a sensible progression. Initial results from one-dimensional transport calculations are used for scoping studies and are followed by detailed two- and three-dimensional analyses to effectively characterize the overall radiation environment. These detail model calculations are essential for accounting for the radiation leakage through ports and other penetrations in the bulk shield. Careful analysis of component activation and radiation damage is cardinal for defining remote handling requirements, in-situ replacement of components, and personnel access at specific locations inside the reactor containment vessel.

  13. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A. (Livermore, CA)

    2011-03-15T23:59:59.000Z

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more frusto-conically-tapered telescoping rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration by the friction fit of adjacent pairs of frusto-conically-tapered rings to each other.

  14. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler, Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2007-05-22T23:59:59.000Z

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  15. Portable convertible blast effects shield

    DOE Patents [OSTI]

    Pastrnak, John W. (Livermore, CA); Hollaway, Rocky (Modesto, CA); Henning, Carl D. (Livermore, CA); Deteresa, Steve (Livermore, CA); Grundler, Walter (Hayward, CA); Hagler,; Lisle B. (Berkeley, CA); Kokko, Edwin (Dublin, CA); Switzer, Vernon A (Livermore, CA)

    2010-10-26T23:59:59.000Z

    A rapidly deployable portable convertible blast effects shield/ballistic shield includes a set two or more telescoping cylindrical rings operably connected to each other to convert between a telescopically-collapsed configuration for storage and transport, and a telescopically-extended upright configuration forming an expanded inner volume. In a first embodiment, the upright configuration provides blast effects shielding, such as against blast pressures, shrapnel, and/or fire balls. And in a second embodiment, the upright configuration provides ballistic shielding, such as against incoming weapons fire, shrapnel, etc. Each ring has a high-strength material construction, such as a composite fiber and matrix material, capable of substantially inhibiting blast effects and impinging projectiles from passing through the shield. And the set of rings are releasably securable to each other in the telescopically-extended upright configuration, such as by click locks.

  16. Welding shield for coupling heaters

    DOE Patents [OSTI]

    Menotti, James Louis (Dickinson, TX)

    2010-03-09T23:59:59.000Z

    Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

  17. The Anticoincidence Shield of the PAMELA

    E-Print Network [OSTI]

    Haviland, David

    The Anticoincidence Shield of the PAMELA Satellite Experiment SILVIO ORSI Licentiate Thesis Stockholm, Sweden 2004 #12;#12;Licentiate Thesis The Anticoincidence Shield of the PAMELA Satellite

  18. Preliminary radiation shielding design for BOOMERANG

    E-Print Network [OSTI]

    Donahue, Richard J.

    2002-01-01T23:59:59.000Z

    Preliminary Radiation Shielding Design for BOOMERANG R. J.2003 Abstract Preliminary radiation shielding speci?cationsElectron Photon Stray Radiation from a High Energy Electron

  19. Thermal neutron shield and method of manufacture

    DOE Patents [OSTI]

    Metzger, Bert Clayton; Brindza, Paul Daniel

    2014-03-04T23:59:59.000Z

    A thermal neutron shield comprising boron shielding panels with a high percentage of the element Boron. The panel is least 46% Boron by weight which maximizes the effectiveness of the shielding against thermal neutrons. The accompanying method discloses the manufacture of boron shielding panels which includes enriching the pre-cursor mixture with varying grit sizes of Boron Carbide.

  20. Renormalization plasma shielding effects on scattering entanglement fidelity in dense plasmas

    SciTech Connect (OSTI)

    Lee, Gyeong Won [Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Shim, Jaewon [Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr [Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180-3590 (United States)

    2014-10-15T23:59:59.000Z

    The influence of renormalization plasma screening on the entanglement fidelity for the elastic electron-atom scattering is investigated in partially ionized dense hydrogen plasmas. The partial wave analysis and effective interaction potential are employed to obtain the scattering entanglement fidelity in dense hydrogen plasmas as functions of the collision energy, the Debye length, and the renormalization parameter. It is found that the renormalization plasma shielding enhances the scattering entanglement fidelity. Hence, we show that the transmission of the quantum information can be increased about 10% due to the renormalization shielding effect in dense hydrogen plasmas. It is also found that the renormalization shielding effect on the entanglement fidelity for the electron-atom collision increases with an increase of the collision energy. In addition, the renormalization shielding function increases with increasing collision energy and saturates to the unity with an increase of the Debye length.

  1. Radiation shielding materials and containers incorporating same

    DOE Patents [OSTI]

    Mirsky, Steven M. (Greenbelt, MD); Krill, Stephen J. (Arlington, VA); Murray, Alexander P. (Gaithersburg, MD)

    2005-11-01T23:59:59.000Z

    An improved radiation shielding material and storage systems for radioactive materials incorporating the same. The PYRolytic Uranium Compound ("PYRUC") shielding material is preferably formed by heat and/or pressure treatment of a precursor material comprising microspheres of a uranium compound, such as uranium dioxide or uranium carbide, and a suitable binder. The PYRUC shielding material provides improved radiation shielding, thermal characteristic, cost and ease of use in comparison with other shielding materials. The shielding material can be used to form containment systems, container vessels, shielding structures, and containment storage areas, all of which can be used to house radioactive waste. The preferred shielding system is in the form of a container for storage, transportation, and disposal of radioactive waste. In addition, improved methods for preparing uranium dioxide and uranium carbide microspheres for use in the radiation shielding materials are also provided.

  2. Radiation Shielding Materials and Containers Incorporating Same

    DOE Patents [OSTI]

    Mirsky, Steven M.; Krill, Stephen J.; and Murray, Alexander P.

    2005-11-01T23:59:59.000Z

    An improved radiation shielding material and storage systems for radioactive materials incorporating the same. The PYRolytic Uranium Compound (''PYRUC'') shielding material is preferably formed by heat and/or pressure treatment of a precursor material comprising microspheres of a uranium compound, such as uranium dioxide or uranium carbide, and a suitable binder. The PYRUC shielding material provides improved radiation shielding, thermal characteristic, cost and ease of use in comparison with other shielding materials. The shielding material can be used to form containment systems, container vessels, shielding structures, and containment storage areas, all of which can be used to house radioactive waste. The preferred shielding system is in the form of a container for storage, transportation, and disposal of radioactive waste. In addition, improved methods for preparing uranium dioxide and uranium carbide microspheres for use in the radiation shielding materials are also provided.

  3. Penetration seals for TFTR shielding

    SciTech Connect (OSTI)

    Hondorp, H.L.

    1980-12-01T23:59:59.000Z

    The penetrations of the shielding provided for TFTR are required to be sealed to avoid radiation streaming. This report provides a discussion of the properties required for these penetration seals. Several alternate designs are discussed and evaluated and designs recommended for specific applications.

  4. Light shield for solar concentrators

    DOE Patents [OSTI]

    Plesniak, Adam P.; Martins, Guy L.

    2014-08-26T23:59:59.000Z

    A solar receiver unit including a housing defining a recess, a cell assembly received in the recess, the cell assembly including a solar cell, and a light shield received in the recess and including a body and at least two tabs, the body defining a window therein, the tabs extending outward from the body and being engaged with the recess, wherein the window is aligned with the solar cell.

  5. A Miniature Continuous Adiabatic Demagnetization Refrigerator with compact shielded superconducting magnets.

    E-Print Network [OSTI]

    Timbie, Peter

    insulated from the bath. The refrigeration cycle exploits the interaction between the atomic magnetic a magnetic field is applied to a param- agnetic refrigerant, its magnetic spins are aligned and orderedA Miniature Continuous Adiabatic Demagnetization Refrigerator with compact shielded superconducting

  6. Hot Cell Window Shielding Analysis Using MCNP

    SciTech Connect (OSTI)

    Chad L. Pope; Wade W. Scates; J. Todd Taylor

    2009-05-01T23:59:59.000Z

    The Idaho National Laboratory Materials and Fuels Complex nuclear facilities are undergoing a documented safety analysis upgrade. In conjunction with the upgrade effort, shielding analysis of the Fuel Conditioning Facility (FCF) hot cell windows has been conducted. This paper describes the shielding analysis methodology. Each 4-ft thick window uses nine glass slabs, an oil film between the slabs, numerous steel plates, and packed lead wool. Operations in the hot cell center on used nuclear fuel (UNF) processing. Prior to the shielding analysis, shield testing with a gamma ray source was conducted, and the windows were found to be very effective gamma shields. Despite these results, because the glass contained significant amounts of lead and little neutron absorbing material, some doubt lingered regarding the effectiveness of the windows in neutron shielding situations, such as during an accidental criticality. MCNP was selected as an analysis tool because it could model complicated geometry, and it could track gamma and neutron radiation. A bounding criticality source was developed based on the composition of the UNF. Additionally, a bounding gamma source was developed based on the fission product content of the UNF. Modeling the windows required field inspections and detailed examination of drawings and material specifications. Consistent with the shield testing results, MCNP results demonstrated that the shielding was very effective with respect to gamma radiation, and in addition, the analysis demonstrated that the shielding was also very effective during an accidental criticality.

  7. Relative radiant heat absorption characteristics of two types of mirror shields and a polished aluminum shield 

    E-Print Network [OSTI]

    Herron, Steven Douglas

    1973-01-01T23:59:59.000Z

    RELATIVE RADIANT HEAT ABSORPTION CHARACTERISTICS OF TWO TYPES OF MIRROR SHIELDS AND A POLISHED ALUMINUM SHIELD A Thesis by STEVEN DOUGLAS HERRON Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1973 Major Subject: Industrial Hygiene RELATIVE RADIANT HEAT ABSORPTION CHARACTERISTICS OF TWO TYPES OF MIRROR SHIELDS AND A POLISHED ALUMINUM SHIELD A Thesis by STEVEN DOUGLAS HERRON Approved...

  8. Hewlett and Duncan - Atomic Shield | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently20,000 RussianBy: Thomas P. D'Agostino,GlenLearning andDesign inImageEnergy andHewlett,

  9. A' Brief. History of the Tower Shielding Facility and Tower Shielding Facility

    E-Print Network [OSTI]

    A' Brief. History of the Tower Shielding Facility and Programs Tower Shielding Facility Hoisting Equipment and Handling Pool Tower Shielding Reactor TSR-II Assembly and Outer Reflector Reactor Suspension buildings (1953) 0 Towers form a lOO- by 200-j? rectangle 0 Unit weight of towers less than 400 lb/' - gives

  10. Shielding, Levitation, Propulsion G. W. Jewell, Chariman Method for expanding the uniformly shielded area in a short-length

    E-Print Network [OSTI]

    Paperno, Eugene

    Shielding, Levitation, Propulsion G. W. Jewell, Chariman Method for expanding the uniformly shielded area in a short-length open-ended cylindrical magnetic shield K. Oshita, I. Sasada,a) H. Naka shielded area of the axial magnetic field in a relatively short, open-structure axial magnetic shield can

  11. Thermal neutron shield and method of manufacture

    DOE Patents [OSTI]

    Brindza, Paul Daniel; Metzger, Bert Clayton

    2013-05-28T23:59:59.000Z

    A thermal neutron shield comprising concrete with a high percentage of the element Boron. The concrete is least 54% Boron by weight which maximizes the effectiveness of the shielding against thermal neutrons. The accompanying method discloses the manufacture of Boron loaded concrete which includes enriching the concrete mixture with varying grit sizes of Boron Carbide.

  12. Shielding superconductors with thin films

    E-Print Network [OSTI]

    Posen, Sam; Catelani, Gianluigi; Liepe, Matthias U; Sethna, James P

    2015-01-01T23:59:59.000Z

    Determining the optimal arrangement of superconducting layers to withstand large amplitude AC magnetic fields is important for certain applications such as superconducting radiofrequency cavities. In this paper, we evaluate the shielding potential of the superconducting film/insulating film/superconductor (SIS') structure, a configuration that could provide benefits in screening large AC magnetic fields. After establishing that for high frequency magnetic fields, flux penetration must be avoided, the superheating field of the structure is calculated in the London limit both numerically and, for thin films, analytically. For intermediate film thicknesses and realistic material parameters we also solve numerically the Ginzburg-Landau equations. It is shown that a small enhancement of the superheating field is possible, on the order of a few percent, for the SIS' structure relative to a bulk superconductor of the film material, if the materials and thicknesses are chosen appropriately.

  13. Impact of External Heat-shielding Techniques on Shell Surface...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    External Heat-shielding Techniques on Shell Surface Temperatures and Dynamic Shell Thermal Deformation of Diesel Engine Emission Control Systems Impact of External Heat-shielding...

  14. Hot cell shield plug extraction apparatus

    DOE Patents [OSTI]

    Knapp, Philip A. (Moore, ID); Manhart, Larry K. (Pingree, ID)

    1995-01-01T23:59:59.000Z

    An apparatus is provided for moving shielding plugs into and out of holes in concrete shielding walls in hot cells for handling radioactive materials without the use of external moving equipment. The apparatus provides a means whereby a shield plug is extracted from its hole and then swung approximately 90 degrees out of the way so that the hole may be accessed. The apparatus uses hinges to slide the plug in and out and to rotate it out of the way, the hinge apparatus also supporting the weight of the plug in all positions, with the load of the plug being transferred to a vertical wall by means of a bolting arrangement.

  15. Study of Active Shielding for {gamma} - Spectrometers

    SciTech Connect (OSTI)

    Bikit, I.; Mrdja, D.; Forkapic, S.; Todorovic, N.; Veskovic, M.; Slivka, J.; Conkic, Lj.; Krmar, M.; Varga, E. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21 000 Novi Sad (Serbia and Montenegro)

    2006-04-26T23:59:59.000Z

    The features of the ground located gamma ray spectrometer shielded passively with 12 cm of lead and actively by five 0.5m x 0.5m x 0.05m plastic veto shields are described. The detector mass related background was 0.345 C/kg s. The 511 keV annihilation line was reduced by the factor of 7 by the anticoincidence gate. It is shown that the plastic shields increase the neutron capture gamma line intensities due to neutron thermalization.

  16. Seismic Crystals And Earthquake Shield Application

    E-Print Network [OSTI]

    B. Baykant Alagoz; Serkan Alagoz

    2009-05-15T23:59:59.000Z

    We theoretically demonstrate that earthquake shield made of seismic crystal can damp down surface waves, which are the most destructive type for constructions. In the paper, seismic crystal is introduced in aspect of band gaps (Stop band) and some design concepts for earthquake and tsunami shielding were discussed in theoretical manner. We observed in our FDTD based 2D elastic wave simulations that proposed earthquake shield could provide about 0.5 reductions in magnitude of surface wave on the Richter scale. This reduction rate in magnitude can considerably reduce destructions in the case of earthquake.

  17. SHIELDED CONTAINER COMPLETENESS COMMENTS July 13, 2010

    E-Print Network [OSTI]

    the possible dose rate changes at the surface of the package for the intended payloads to be shipped. The same concerns as outlined above apply here. Reference WTS 2008. Shielded Container Type A Evaluation Report, ECO

  18. X-ray transmissive debris shield

    DOE Patents [OSTI]

    Spielman, Rick B. (Albuquerque, NM)

    1994-01-01T23:59:59.000Z

    A composite window structure is described for transmitting x-ray radiation and for shielding radiation generated debris. In particular, separate layers of different x-ray transmissive materials are laminated together to form a high strength, x-ray transmissive debris shield which is particularly suited for use in high energy fluences. In one embodiment, the composite window comprises alternating layers of beryllium and a thermoset polymer.

  19. Shielded beam delivery apparatus and method

    DOE Patents [OSTI]

    Hershcovitch, Ady; Montano, Rory Dominick

    2006-07-11T23:59:59.000Z

    An apparatus includes a plasma generator aligned with a beam generator for producing a plasma to shield an energized beam. An electrode is coaxially aligned with the plasma generator and followed in turn by a vortex generator coaxially aligned with the electrode. A target is spaced from the vortex generator inside a fluid environment. The electrode is electrically biased relative to the electrically grounded target for driving the plasma toward the target inside a vortex shield.

  20. Space Shielding Materials for Prometheus Application

    SciTech Connect (OSTI)

    R. Lewis

    2006-01-20T23:59:59.000Z

    At the time of Prometheus program restructuring, shield material and design screening efforts had progressed to the point where a down-selection from approximately eighty-eight materials to a set of five ''primary'' materials was in process. The primary materials were beryllium (Be), boron carbide (B{sub 4}C), tungsten (W), lithium hydride (LiH), and water (H{sub 2}O). The primary materials were judged to be sufficient to design a Prometheus shield--excluding structural and insulating materials, that had not been studied in detail. The foremost preconceptual shield concepts included: (1) a Be/B{sub 4}C/W/LiH shield; (2) a Be/B{sub 4}C/W shield; (3) and a Be/B{sub 4}C/H{sub 2}O shield. Since the shield design and materials studies were still preliminary, alternative materials (e.g., {sup nal}B or {sup 10}B metal) were still being screened, but at a low level of effort. Two competing low mass neutron shielding materials are included in the primary materials due to significant materials uncertainties in both. For LiH, irradiation-induced swelling was the key issue, whereas for H{sub 2}O, containment corrosion without active chemistry control was key, Although detailed design studies are required to accurately estimate the mass of shields based on either hydrogenous material, both are expected to be similar in mass, and lower mass than virtually any alternative. Unlike Be, W, and B{sub 4}C, which are not expected to have restrictive temperature limits, shield temperature limits and design accommodations are likely to be needed for either LiH or H{sub 2}O. The NRPCT focused efforts on understanding swelting of LiH, and observed, from approximately fifty prior irradiation tests, that either casting ar thorough out-gassing should reduce swelling. A potential contributor to LiH swelling appears to be LiOH contamination due to exposure to humid air, that can be eliminated by careful processing. To better understand LiH irradiation performance and mitigate the risks in LiH development for a project with an aggressive schedule like JIMO, some background or advanced development effort for LiH should be considered for future space reactor projects.

  1. SONY GXB5005 GPS RECEIVER DATA Without shield can Installed With shield can in place

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    SONY GXB5005 GPS RECEIVER DATA Without shield can Installed With shield can in place (for illustrative purposes only) The Sony GXB5005 GPS receiver is a miniature 12 channel GPS module with support for WAAS/EGNOS augmented positioning. The receiver is based on Sony's CXD2951 single-chip GPS receiver IC

  2. Test program element II blanket and shield thermal-hydraulic and thermomechanical testing, experimental facility survey

    SciTech Connect (OSTI)

    Ware, A.G.; Longhurst, G.R.

    1981-12-01T23:59:59.000Z

    This report presents results of a survey conducted by EG and G Idaho to determine facilities available to conduct thermal-hydraulic and thermomechanical testing for the Department of Energy Office of Fusion Energy First Wall/Blanket/Shield Engineering Test Program. In response to EG and G queries, twelve organizations (in addition to EG and G and General Atomic) expressed interest in providing experimental facilities. A variety of methods of supplying heat is available.

  3. Numerical estimation on free electrons generated by shielded radioactive materials under various gaseous environments

    SciTech Connect (OSTI)

    Kim, D. S. [Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); Lee, W. S.; So, J. H. [Agency for Defence Development (ADD), Daejeon 305-152 (Korea, Republic of); Choi, E. M. [Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of); School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of)

    2013-06-15T23:59:59.000Z

    We report simulation results on generation of free electrons due to the presence of radioactive materials under controlled pressure and gases using a general Monte Carlo transport code (MCNPX). A radioactive material decays to lower atomic number, simultaneously producing high energy gamma rays that can generate free electrons via various scattering mechanisms. This paper shows detailed simulation works for answering how many free electrons can be generated under the existence of shielded radioactive materials as a function of pressure and types of gases.

  4. Cosmic Ray Interactions in Shielding Materials

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.; Orrell, John L.; Berguson, Timothy J.; Troy, Meredith D.

    2011-09-08T23:59:59.000Z

    This document provides a detailed study of materials used to shield against the hadronic particles from cosmic ray showers at Earth’s surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during transport for the MAJORANA collaboration. The materials suitable for cosmic-ray shield design are materials such as lead and iron that will stop the primary protons, and materials like polyethylene, borated polyethylene, concrete and water that will stop the induced neutrons. The interaction of the different cosmic-ray components at ground level (protons, neutrons, muons) with their wide energy range (from kilo-electron volts to giga-electron volts) is a complex calculation. Monte Carlo calculations have proven to be a suitable tool for the simulation of nucleon transport, including hadron interactions and radioactive isotope production. The industry standard Monte Carlo simulation tool, Geant4, was used for this study. The result of this study is the assertion that activation at Earth’s surface is a result of the neutronic and protonic components of the cosmic-ray shower. The best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.

  5. Power converter having improved EMI shielding

    DOE Patents [OSTI]

    Beihoff, Bruce C.; Kehl, Dennis L.; Gettelfinger, Lee A.; Kaishian, Steven C.; Phillips, Mark G.; Radosevich, Lawrence D.

    2006-06-13T23:59:59.000Z

    EMI shielding is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  6. Vehicle drive module having improved EMI shielding

    DOE Patents [OSTI]

    Beihoff, Bruce C.; Kehl, Dennis L.; Gettelfinger, Lee A.; Kaishian, Steven C.; Phillips, Mark G.; Radosevich, Lawrence D.

    2006-11-28T23:59:59.000Z

    EMI shielding in an electric vehicle drive is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  7. The Interaction of Debye-Shielded Particles

    SciTech Connect (OSTI)

    Buss, Richard J.; Riley, Merle E.

    1999-04-01T23:59:59.000Z

    Macroscopic particles or solid surfaces in contact with a typical low-temperature plasma immediately charge negatively and surround themselves with an electron-depleted region of positive charge. This Debye shielding effect is involved in the Debye-Huckel theory in liquids and plasma sheath formation in the gas phase. In this report, the interaction between such screened particles is found by using the same basic approximation that is used in constructing the Debye shielding potential itself. The results demonstrate that a significant attraction exists between the particles, and, if conditions are right, this attractive force can contribute to the generation of particulate plasma crystals.

  8. Including shielding effects in application of the TPCA method for detection of embedded radiation sources.

    SciTech Connect (OSTI)

    Johnson, William C.; Shokair, Isaac R.

    2011-12-01T23:59:59.000Z

    Conventional full spectrum gamma spectroscopic analysis has the objective of quantitative identification of all the radionuclides present in a measurement. For low-energy resolution detectors such as NaI, when photopeaks alone are not sufficient for complete isotopic identification, such analysis requires template spectra for all the radionuclides present in the measurement. When many radionuclides are present it is difficult to make the correct identification and this process often requires many attempts to obtain a statistically valid solution by highly skilled spectroscopists. A previous report investigated using the targeted principal component analysis method (TPCA) for detection of embedded sources for RPM applications. This method uses spatial/temporal information from multiple spectral measurements to test the hypothesis of the presence of a target spectrum of interest in these measurements without the need to identify all the other radionuclides present. The previous analysis showed that the TPCA method has significant potential for automated detection of target radionuclides of interest, but did not include the effects of shielding. This report complements the previous analysis by including the effects of spectral distortion due to shielding effects for the same problem of detection of embedded sources. Two examples, one with one target radionuclide and the other with two, show that the TPCA method can successfully detect shielded targets in the presence of many other radionuclides. The shielding parameters are determined as part of the optimization process using interpolation of library spectra that are defined on a 2D grid of atomic numbers and areal densities.

  9. Beer and Economic Growth Dr. Martin Shields

    E-Print Network [OSTI]

    Beer and Economic Growth Dr. Martin Shields Regional Economics Institute Colorado State University to the rest of the world #12;Industry Trends · Over the past 10 years, the growth in craft beer has significantly altered the industry · While overall beer sales are relatively flat, market share of craft brewers

  10. Oxygen Abundance Measurements of SHIELD Galaxies

    E-Print Network [OSTI]

    Haurberg, Nathalie C; Cannon, John M; Marshall, Melissa V

    2015-01-01T23:59:59.000Z

    We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. H$\\alpha$ images from the WIYN 3.5m telescope show that these 8 SHIELD galaxies each possess one or two active star-forming regions which were targeted with long-slit spectral observations using the Mayall 4m telescope at KPNO. We obtained a direct measurement of the electron temperature by detection of the weak [O III] $\\lambda$4363 line in 2 of the HII regions. Oxygen abundances for the other HII regions were estimated using a strong-line method. When the SHIELD galaxies are plotted on a B-band luminosity-metallicity diagram they appear to suggest a slightly shallower slope to the relationship than normally seen. However, that offset is systematically reduced when the near-infrared luminosity is used ins...

  11. Effective shielding to measure beam current from an ion source

    SciTech Connect (OSTI)

    Bayle, H., E-mail: bayle@bergoz.com [Bergoz Instrumentation, Saint-Genis-Pouilly (France); Delferrière, O.; Gobin, R.; Harrault, F.; Marroncle, J.; Senée, F.; Simon, C.; Tuske, O. [CEA, Saclay (France)] [CEA, Saclay (France)

    2014-02-15T23:59:59.000Z

    To avoid saturation, beam current transformers must be shielded from solenoid, quad, and RFQ high stray fields. Good understanding of field distribution, shielding materials, and techniques is required. Space availability imposes compact shields along the beam pipe. This paper describes compact effective concatenated magnetic shields for IFMIF-EVEDA LIPAc LEBT and MEBT and for FAIR Proton Linac injector. They protect the ACCT Current Transformers beyond 37 mT radial external fields. Measurements made at Saclay on the SILHI source are presented.

  12. Engineering of Ferrite-Graphite Composite Media for Microwave Shields

    E-Print Network [OSTI]

    Koledintseva, Marina Y.

    Engineering of Ferrite-Graphite Composite Media for Microwave Shields Marina Koledintseva, PoornaAA@mpei.ru Abstract-- An electromagnetic shielding of objects using ferrite-graphite composites is considered- shielding; dielectric base material; ferrite- graphite composite, Maxwell Garnett formulation I

  13. On vapor shielding of dust grains of iron, molybdenum, and tungsten in fusion plasmas

    SciTech Connect (OSTI)

    Brown, B. T.; Smirnov, R. D., E-mail: rsmirnov@ucsd.edu; Krasheninnikov, S. I. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0411 (United States)] [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0411 (United States)

    2014-02-15T23:59:59.000Z

    The shielding effects of ablation cloud around a small dust grain composed of iron, molybdenum, or tungsten in fusion plasmas are considered. These include collisional dissipation of momentum flux of impinging plasma ions, heat transfer by secondary plasma created due to electron impact ionization of the ablated atoms, and radiative plasma power losses in the ablation cloud. The maximum radius, which limits applicability of existing dust-plasma interaction models neglecting the cloud shielding effects, for dust grains of the considered high-Z metals is calculated as function of plasma parameters. The thermal bifurcation triggered by thermionic electron emission from dust grains, observed for some of the considered materials, is analyzed. The results are compared with previous calculations for dust composed of low-Z fusion related materials, i.e., lithium, beryllium, and carbon.

  14. Magnetic shielding for the Fermilab Vertical Cavity Test Facility

    SciTech Connect (OSTI)

    Ginsburg, Camille M.; Reid, Clark; Sergatskov, Dmitri A.; /Fermilab

    2008-09-01T23:59:59.000Z

    A superconducting RF cavity has to be shielded from magnetic fields present during cool down below the critical temperature to avoid freezing in the magnetic flux at localized impurities, thereby degrading the cavity intrinsic quality factor Q{sub 0}. The magnetic shielding designed for the Fermilab vertical cavity test facility (VCTF), a facility for CW RF vertical testing of bare ILC 1.3 GHz 9-cell SRF cavities, was recently completed. For the magnetic shielding design, we used two cylindrical layers: a room temperature 'outer' shield of Amumetal (80% Ni alloy), and a 2K 'inner' shield of Cryoperm 10. The magnetic and mechanical design of the magnetic shielding and measurement of the remanent magnetic field inside the shielding are described.

  15. Supplemental heating of deposition tooling shields

    DOE Patents [OSTI]

    Ohlhausen, James A. (Albuquerque, NM); Peebles, Diane E. (Albuquerque, NM); Hunter, John A. (Albuquerque, NM); Eckelmeyer, Kenneth H. (Albuquerque, NM)

    2000-01-01T23:59:59.000Z

    A method of reducing particle generation from the thin coating deposited on the internal surfaces of a deposition chamber which undergoes temperature variation greater than 100.degree. C. comprising maintaining the temperature variation of the internal surfaces low enough during the process cycle to keep thermal expansion stresses between the coating and the surfaces under 500 MPa. For titanium nitride deposited on stainless steel, this means keeping temperature variations under approximately 70.degree. C. in a chamber that may be heated to over 350.degree. C. during a typical processing operation. Preferably, a supplemental heater is mounted behind the upper shield and controlled by a temperature sensitive element which provides feedback control based on the temperature of the upper shield.

  16. Electronically shielded solid state charged particle detector

    DOE Patents [OSTI]

    Balmer, D.K.; Haverty, T.W.; Nordin, C.W.; Tyree, W.H.

    1996-08-20T23:59:59.000Z

    An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite. 1 fig.

  17. Electronically shielded solid state charged particle detector

    DOE Patents [OSTI]

    Balmer, David K. (155 Coral Way, Broomfield, CO 80020); Haverty, Thomas W. (1173 Logan, Northglenn, CO 80233); Nordin, Carl W. (7203 W. 32nd Ave., Wheatridge, CO 80033); Tyree, William H. (1977 Senda Rocosa, Boulder, CO 80303)

    1996-08-20T23:59:59.000Z

    An electronically shielded solid state charged particle detector system having enhanced radio frequency interference immunity includes a detector housing with a detector entrance opening for receiving the charged particles. A charged particle detector having an active surface is disposed within the housing. The active surface faces toward the detector entrance opening for providing electrical signals representative of the received charged particles when the received charged particles are applied to the active surface. A conductive layer is disposed upon the active surface. In a preferred embodiment, a nonconductive layer is disposed between the conductive layer and the active surface. The conductive layer is electrically coupled to the detector housing to provide a substantially continuous conductive electrical shield surrounding the active surface. The inner surface of the detector housing is supplemented with a radio frequency absorbing material such as ferrite.

  18. Spallation Neutron Source Radiation Shielding Issues

    SciTech Connect (OSTI)

    Azmy, Y.Y.; Barnes, J.M.; Drischler, J.D.; Johnston, J.O.; Lillie, R.A.; McNeilly, G.S.; Santoro, R.T.

    1999-11-14T23:59:59.000Z

    This paper summarizes results of Spallation Neutron Source calculations to estimate radiation hazards and shielding requirements for activated Mercury, target components, target cooling water, and {sup 7}Be plateout. Dose rates in the accelerator tunnel from activation of magnets and concrete were investigated. The impact of gaps and other streaming paths on the radiation environment inside the test cell during operation and after shutdown were also assessed.

  19. Enrichment Determination of Uranium in Shielded Configurations

    SciTech Connect (OSTI)

    Crye, Jason Michael [ORNL] [ORNL; Hall, Howard L [ORNL] [ORNL; McConchie, Seth M [ORNL] [ORNL; Mihalczo, John T [ORNL] [ORNL; Pena, Kirsten E [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The determination of the enrichment of uranium is required in many safeguards and security applications. Typical methods of determining the enrichment rely on detecting the 186 keV gamma ray emitted by {sup 235}U. In some applications, the uranium is surrounded by external shields, and removal of the shields is undesirable. In these situations, methods relying on the detection of the 186 keV gamma fail because the gamma ray is shielded easily. Oak Ridge National Laboratory (ORNL) has previously measured the enrichment of shielded uranium metal using active neutron interrogation. The method consists of measuring the time distribution of fast neutrons from induced fissions with large plastic scintillator detectors. To determine the enrichment, the measurements are compared to a calibration surface that is created from Monte Carlo simulations where the enrichment in the models is varied. In previous measurements, the geometry was always known. ORNL is extending this method to situations where the geometry and materials present are not known in advance. In the new method, the interrogating neutrons are both time and directionally tagged, and an array of small plastic scintillators measures the uncollided interrogating neutrons. Therefore, the attenuation through the item along many different paths is known. By applying image reconstruction techniques, an image of the item is created which shows the position-dependent attenuation. The image permits estimating the geometry and materials present, and these estimates are used as input for the Monte Carlo simulations. As before, simulations predict the time distribution of induced fission neutrons for different enrichments. Matching the measured time distribution to the closest prediction from the simulations provides an estimate of the enrichment. This presentation discusses the method and provides results from recent simulations that show the importance of knowing the geometry and materials from the imaging system.

  20. Transparent self-cleaning dust shield

    DOE Patents [OSTI]

    Mazumder, Malay K.; Sims, Robert A.; Wilson, James D.

    2005-06-28T23:59:59.000Z

    A transparent electromagnetic shield to protect solar panels and the like from dust deposition. The shield is a panel of clear non-conducting (dielectric) material with embedded parallel electrodes. The panel is coated with a semiconducting film. Desirably the electrodes are transparent. The electrodes are connected to a single-phase AC signal or to a multi-phase AC signal that produces a travelling electromagnetic wave. The electromagnetic field produced by the electrodes lifts dust particles away from the shield and repels charged particles. Deposited dust particles are removed when the electrodes are activated, regardless of the resistivity of the dust. Electrostatic charges on the panel are discharged by the semiconducting film. When used in conjunction with photovoltaic cells, the power for the device may be obtained from the cells themselves. For other surfaces, such as windshields, optical windows and the like, the power must be derived from an external source. One embodiment of the invention employs monitoring and detection devices to determine when the level of obscuration of the screen by dust has reached a threshold level requiring activation of the dust removal feature.

  1. Radiation Shielding for Electronic Devices OperatingRadiation Shielding for Electronic Devices Operating in XFEL Environment: Monte Carlo Simulations andin XFEL Environment: Monte Carlo Simulations and

    E-Print Network [OSTI]

    Radiation Shielding for Electronic Devices OperatingRadiation Shielding for Electronic Devices undergroundund tunnel. All LLRF Electronic Devices, made of radiation sensitivetunnel. All LLRF Electronic principle of the dedicated radiationtion shielding for the electronic devices to be operating in XFEL

  2. Shielding aspects of D- sup 3 He fusion power reactors

    SciTech Connect (OSTI)

    El-Guebaly, L.A. (Wisconsin Univ., Madison, WI (United States). Fusion Technology Inst.)

    1992-08-01T23:59:59.000Z

    In this paper the implications of the D-{sup 3}He fuel cycle on shielding design are investigated for tokamak power reactors of the ARIES/Apollo class. The prime function of the shield is to protect the superconducting magnets against radiation. A variety of shield options is examined, and the various shields are optimized for the D-{sup 3}He neutron spectrum. The results demonstrate the relative merits of the various materials as a function of the shield thickness. In the first wall/shield, low-activation structural materials (such as Tenelon, modified HT-9, silicon carbide composites, and carbon-carbon composites) were employed to reduce the radioactive inventory and increase the safety margin in case of accidents. A comparison between the different shield options based on detailed neutronics, environmental/safety, and economic assessments has led to the selection of the reference shield design. The first-wall/shield structure is made of an elementally tailored ferritic steel (MHT-9), and the thermal energy is converted through an organic coolant at 44% efficiency. The safety features of the low-activation steel shield, along with the low neutron production in the D-{sup 3}He fuel cycle, enable the ARIES-III/Apollo design to achieve acceptable environmental and safety characteristics.

  3. Cross Section Evaluation Group shielding benchmark compilation. Volume II

    SciTech Connect (OSTI)

    Rose, P.F.; Roussin, R.W.

    1983-12-01T23:59:59.000Z

    At the time of the release of ENDF/B-IV in 1974, the Shielding Subcommittee had identified a series of 12 shielding data testing benchmarks (the SDT series). Most were used in the ENDF/B-IV data testing effort. A new concept and series was begun in the interim, the so-called Shielding Benchmark (SB) series. An effort was made to upgrade the SDT series as far as possible and to add new SB benchmarks. In order to be designated in the SB class, both an experiment and analysis must have been performed. The current recommended benchmark for Shielding Data Testing are listed. Until recently, the philosophy has been to include only citations to published references for shielding benchmarks. It is now our intention to provide adequate information in this volume for proper analysis of any new benchmarks added to the collection. These compilations appear in Section II, with the SB5 Fusion Reactor Shielding Benchmark as the first entry.

  4. Optimization of a Mu2e production solenoid heat and radiation shield using MARS15

    SciTech Connect (OSTI)

    Pronskikh, V.S.; Mokhov, N.V.; /Fermilab

    2011-02-01T23:59:59.000Z

    A Monte-Carlo study of several Mu2e Production Solenoid (PS) absorber (heat shield) versions using the MARS15 code has been performed. Optimizations for material as well as cost (amount of tungsten) have been carried out. Studied are such quantities as the number of displacements per atom (DPA) in the helium-cooled solenoid superconducting coils, power density and dynamic heat load in various parts of the PS and its surrounding structures. Prompt dose, residual dose, secondary particle flux are also simulated in the PS structures and the experimental hall. A preliminary choice of the PS absorber design is made on the ground of these studies.

  5. Optimal Shielding for Minimum Materials Cost of Mass

    SciTech Connect (OSTI)

    Woolley, Robert D. [PPPL

    2014-08-01T23:59:59.000Z

    Material costs dominate some shielding design problems. This is certainly the case for manned nuclear power space applications for which shielding is essential and the cost of launching by rocket from earth is high. In such situations or in those where shielding volume or mass is constrained, it is important to optimize the design. Although trial and error synthesis methods may succeed a more systematic approach is warranted. Design automation may also potentially reduce engineering costs.

  6. Shielded serpentine traveling wave tube deflection structure

    DOE Patents [OSTI]

    Hudson, Charles L. (Santa Barbara, CA); Spector, Jerome (Berkeley, CA)

    1994-01-01T23:59:59.000Z

    A shielded serpentine slow wave deflection structure (10) having a serpene signal conductor (12) within a channel groove (46). The channel groove (46) is formed by a serpentine channel (20) in a trough plate (18) and a ground plane (14). The serpentine signal conductor (12) is supported at its ends by coaxial feed through connectors 28. A beam interaction trough (22) intersects the channel groove (46) to form a plurality of beam interaction regions (56) wherein an electron beam (54) may be deflected relative to the serpentine signal conductor (12).

  7. Longwall shield design: is bigger better?

    SciTech Connect (OSTI)

    Barczak, T.M.; Tadolini, S.C. [NIOSH-PRL, Pittsburgh, PA (United States)

    2008-05-15T23:59:59.000Z

    This article evaluates the bigger is better design philosophy for longwall shields. The conventional support design approach based on simplistic models of supporting the full dead weight detached rock masses is replaced by a ground reaction design approach. Here, the goal is to match the support characteristics to the ground response, and not to try and overpower the ground forces with some massive support capability. The ground reaction concept embodies both the force and displacement controlled loading aspects, and therefore provides a more accurate representation of the support loading requirements. 7 figs.

  8. Shields, Michigan: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk, New York: EnergySumoncleShida Battery Technology Co LtdShields,

  9. Gravity Scaling of a Power Reactor Water Shield

    SciTech Connect (OSTI)

    Reid, Robert S.; Pearson, J. Boise [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2008-01-21T23:59:59.000Z

    Water based reactor shielding is being considered as an affordable option for potential use on initial lunar surface reactor power systems. Heat dissipation in the shield from nuclear sources must be rejected by an auxillary thermal hydraulic cooling system. The mechanism for transferring heat through the shield is natural convection between the core surface and an array of thermosyphon radiator elements. Natural convection in a 100 kWt lunar surface reactor shield design has been previously evaluated at lower power levels (Pearson, 2006). The current baseline assumes that 5.5 kW are dissipated in the water shield, the preponderance on the core surface, but with some volumetric heating in the naturally circulating water as well. This power is rejected by a radiator located above the shield with a surface temperature of 370 K. A similarity analysis on a water-based reactor shield is presented examining the effect of gravity on free convection between a radiation shield inner vessel and a radiation shield outer vessel boundaries. Two approaches established similarity: 1) direct scaling of Rayleigh number equates gravity-surface heat flux products, 2) temperature difference between the wall and thermal boundary layer held constant on Earth and the Moon. Nussult number for natural convection (laminar and turbulent) is assumed of form Nu = CRa{sup n}. These combined results estimate similarity conditions under Earth and Lunar gravities. The influence of reduced gravity on the performance of thermosyphon heat pipes is also examined.

  10. Graphene shield enhanced photocathodes and methods for making the same

    DOE Patents [OSTI]

    Moody, Nathan Andrew

    2014-09-02T23:59:59.000Z

    Disclosed are graphene shield enhanced photocathodes, such as high QE photocathodes. In certain embodiments, a monolayer graphene shield membrane ruggedizes a high quantum efficiency photoemission electron source by protecting a photosensitive film of the photocathode, extending operational lifetime and simplifying its integration in practical electron sources. In certain embodiments of the disclosed graphene shield enhanced photocathodes, the graphene serves as a transparent shield that does not inhibit photon or electron transmission but isolates the photosensitive film of the photocathode from reactive gas species, preventing contamination and yielding longer lifetime.

  11. Optimal Magnetic Shield Design with Second–Order Cone ...

    E-Print Network [OSTI]

    2002-10-31T23:59:59.000Z

    Each car is equipped with several super-conducting magnet units which generate ... Passengers inside the car need to be shielded from the magnetic field.

  12. MicroShield/ISOCS gamma modeling comparison.

    SciTech Connect (OSTI)

    Sansone, Kenneth R

    2013-08-01T23:59:59.000Z

    Quantitative radiological analysis attempts to determine the quantity of activity or concentration of specific radionuclide(s) in a sample. Based upon the certified standards that are used to calibrate gamma spectral detectors, geometric similarities between sample shape and the calibration standards determine if the analysis results developed are qualitative or quantitative. A sample analyzed that does not mimic a calibrated sample geometry must be reported as a non-standard geometry and thus the results are considered qualitative and not quantitative. MicroShieldR or ISOCSR calibration software can be used to model non-standard geometric sample shapes in an effort to obtain a quantitative analytical result. MicroShieldR and Canberra's ISOCSR software contain several geometry templates that can provide accurate quantitative modeling for a variety of sample configurations. Included in the software are computational algorithms that are used to develop and calculate energy efficiency values for the modeled sample geometry which can then be used with conventional analysis methodology to calculate the result. The response of the analytical method and the sensitivity of the mechanical and electronic equipment to the radionuclide of interest must be calibrated, or standardized, using a calibrated radiological source that contains a known and certified amount of activity.

  13. Liquid Vortex Shielding for Fusion Energy Applications

    SciTech Connect (OSTI)

    Bardet, Philippe M. [University of California, Berkeley (United States); Supiot, Boris F. [University of California, Berkeley (United States); Peterson, Per F. [University of California, Berkeley (United States); Savas, Oemer [University of California, Berkeley (United States)

    2005-05-15T23:59:59.000Z

    Swirling liquid vortices can be used in fusion chambers to protect their first walls and critical elements from the harmful conditions resulting from fusion reactions. The beam tube structures in heavy ion fusion (HIF) must be shielded from high energy particles, such as neutrons, x-rays and vaporized coolant, that will cause damage. Here an annular wall jet, or vortex tube, is proposed for shielding and is generated by injecting liquid tangent to the inner surface of the tube both azimuthally and axially. Its effectiveness is closely related to the vortex tube flow properties. 3-D particle image velocimetry (PIV) is being conducted to precisely characterize its turbulent structure. The concept of annular vortex flow can be extended to a larger scale to serve as a liquid blanket for other inertial fusion and even magnetic fusion systems. For this purpose a periodic arrangement of injection and suction holes around the chamber circumference are used, generating the layer. Because it is important to match the index of refraction of the fluid with the tube material for optical measurement like PIV, a low viscosity mineral oil was identified and used that can also be employed to do scaled experiments of molten salts at high temperature.

  14. Issues and test requirements in radiation shielding of fusion reactors

    SciTech Connect (OSTI)

    Nakagawa, M.; Abdou, M.A.

    1986-11-01T23:59:59.000Z

    Radiation shield issues for fusion reactors have been investigated and the experiments and facilities required to resolve the issues have been identified and characterized as part of the FINESSE program. This paper summarizes the recommended approach to fusion shield research and development, provides a summary of the necessary experiments and facilities, and presents the results of technical analyses involved.

  15. Issues and test requirements in radiation shielding of fusion reactors

    SciTech Connect (OSTI)

    Nakagawa, M.; Abdou, M.A.

    1986-01-01T23:59:59.000Z

    Radiation shield issues for fusion reactors have been investigated and the experiments and facilities required to resolve the issues have been identified and characterized as part of the FINESSE program. This paper summarizes the recommended approach to fusion shield R and D, provides a summary of the necessary experiments and facilities, and presents the results of technical analyses involved.

  16. General Corrosion and Localized Corrosion of the Drip Shield

    SciTech Connect (OSTI)

    F. Hua

    2004-09-16T23:59:59.000Z

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847]).

  17. Simulations of Magnetic Shields for Spacecraft Simon G. Shepherd

    E-Print Network [OSTI]

    Shepherd, Simon

    magnetosphere around spacecraft: Propulsion and protection Inflating magnetic field can shield particlesSimulations of Magnetic Shields for Spacecraft Simon G. Shepherd Thayer School of Engineering Brian that controls magnetism will control the universe". -- Dick Tracy Patrick Magari and Darin Knaus Creare, Inc

  18. Nanocrystalline Cs{sub x}WO{sub 3} particles: Effects of N{sub 2} annealing on microstructure and near-infrared shielding characteristics

    SciTech Connect (OSTI)

    Liu, Jing-Xiao, E-mail: drliu-shi@dlpu.edu.cn [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Institute of Multidisciplinary Research for Advanced Material, Tohoku University, Sendai, 980-8577,Japan (Japan); Shi, Fei; Dong, Xiao-Li; Xu, Qiang [School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034 (China); Yin, Shu; Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Material, Tohoku University, Sendai, 980-8577,Japan (Japan)

    2013-10-15T23:59:59.000Z

    In order to further improve the near-infrared shielding properties of cesium tungsten bronze (Cs{sub x}WO{sub 3}) for solar filter applications, Cs{sub x}WO{sub 3} particles were prepared by solvothermal reaction method and the effects of nitrogen annealing on the microstructure and near-infrared shielding properties of Cs{sub x}WO{sub 3} were investigated. The obtained Cs{sub x}WO{sub 3} samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and spectrophotometer. The results indicate that nanosheet-like Cs{sub x}WO{sub 3} particles with hexagonal structure began to transform into nanorods after annealed at temperature higher than 600 °C. The near-infrared shielding properties of Cs{sub x}WO{sub 3} particles could be further improved by N{sub 2} annealing at 500–700 °C. Particularly, the 500 °C-annealed Cs{sub x}WO{sub 3} samples in the N{sub 2} atmosphere showed best near-infrared shielding properties. It was suggested that the excellent near-infrared shielding ability of the 500 °C-annealed Cs{sub x}WO{sub 3} samples is correlated with its minimum O/W atomic ratio and most oxygen vacancies. Highlights: • N{sub 2} annealing could further improve the near-infrared (NIR) shielding of Cs{sub x}WO{sub 3}. • Effects of N{sub 2} annealing on microstructure and NIR shielding of Cs{sub x}WO{sub 3} were studied. • The 500 °C-N{sub 2}-annealed Cs{sub x}WO{sub 3} exhibited minimum O/W ratio and most oxygen vacancies. • The 500 °C-N{sub 2}-annealed Cs{sub x}WO{sub 3} particles exhibited best NIR shielding properties.

  19. Fan-fold shielded electrical leads

    DOE Patents [OSTI]

    Rohatgi, R.R.; Cowan, T.E.

    1996-06-11T23:59:59.000Z

    Disclosed are fan-folded electrical leads made from copper cladded Kapton, for example, with the copper cladding on one side serving as a ground plane and the copper cladding on the other side being etched to form the leads. The Kapton is fan folded with the leads located at the bottom of the fan-folds. Electrical connections are made by partially opening the folds of the fan and soldering, for example, the connections directly to the ground plane and/or the lead. The fan folded arrangement produces a number of advantages, such as electrically shielding the leads from the environment, is totally non-magnetic, and has a very low thermal conductivity, while being easy to fabricate. 3 figs.

  20. Protective shield for an instrument probe

    DOE Patents [OSTI]

    Johnsen, Howard A.; Ross, James R.; Birtola, Sal R.

    2004-10-26T23:59:59.000Z

    A shield is disclosed that is particularly useful for protecting exposed optical elements at the end of optical probes used in the analysis of hazardous emissions in and around an industrial environment from the contaminating effects of those emissions. The instant invention provides a hood or cowl in the shape of a right circular cylinder that can be fitted over the end of such optical probes. The hood provides a clear aperture through which the probe can perform unobstructed analysis. The probe optical elements are protected from the external environment by passing a dry gas through the interior of the hood and out through the hood aperture in sufficient quantity and velocity to prevent any significant mixing between the internal and external environments. Additionally, the hood is provided with a cooling jacket to lessen the potential for damaging the probe due to temperature excursions.

  1. Radiolysis Concerns for Water Shielding in Fission Surface Power Applications

    SciTech Connect (OSTI)

    Schoenfeld, Michael P. [NASA Marshall Space Flight Center, ER24, MSFC, AL 35812 (United States); Anghaie, Samim [Innovative Space Power and Propulsion Institute, 800 SW Archer Rd. Bldg.554, P.O. Box 116502, University of Florida, Gainesville, FL 32611-6502 (United States)

    2008-01-21T23:59:59.000Z

    This paper presents an overview of radiolysis concerns with regard to water shields for fission surface power. A review of the radiolysis process is presented and key parameters and trends are identified. From this understanding of the radiolytic decomposition of water, shield pressurization and corrosion are identified as the primary concerns. Existing experimental and modeling data addressing concerns are summarized. It was found that radiolysis of pure water in a closed volume results in minimal, if any net decomposition, and therefore reduces the potential for shield pressurization and corrosion.

  2. Atomic Rydberg Reservoirs for Polar Molecules

    E-Print Network [OSTI]

    Zhao, Bo; Pupillo, Guido; Zoller, Peter

    2011-01-01T23:59:59.000Z

    We discuss laser dressed dipolar and Van der Waals interactions between atoms and polar molecules, so that a cold atomic gas with laser admixed Rydberg levels acts as a designed reservoir for both elastic and inelastic collisional processes. The elastic scattering channel is characterized by large elastic scattering cross sections and repulsive shields to protect from close encounter collisions. In addition, we discuss a dissipative (inelastic) collision where a spontaneously emitted photon carries away (kinetic) energy of the collision partners, thus providing a significant energy loss in a single collision. This leads to the scenario of rapid thermalization and cooling of a molecule in the mK down to the \\mu K regime by cold atoms.

  3. Atomic Rydberg Reservoirs for Polar Molecules

    E-Print Network [OSTI]

    Bo Zhao; Alexander Glätzle; Guido Pupillo; Peter Zoller

    2011-12-18T23:59:59.000Z

    We discuss laser dressed dipolar and Van der Waals interactions between atoms and polar molecules, so that a cold atomic gas with laser admixed Rydberg levels acts as a designed reservoir for both elastic and inelastic collisional processes. The elastic scattering channel is characterized by large elastic scattering cross sections and repulsive shields to protect from close encounter collisions. In addition, we discuss a dissipative (inelastic) collision where a spontaneously emitted photon carries away (kinetic) energy of the collision partners, thus providing a significant energy loss in a single collision. This leads to the scenario of rapid thermalization and cooling of a molecule in the mK down to the \\mu K regime by cold atoms.

  4. Addendum to NuMI shielding assessment

    SciTech Connect (OSTI)

    Vaziri, Kamran; /Fermilab

    2007-10-01T23:59:59.000Z

    The original safety assessment and the Safety Envelope for the NuMI beam line corresponds to 400 kW of beam power. The Main Injector is currently capable of and approved for producing 500 kW of beam power2. However, operation of the NuMI beam line at 400 kW of power brings up the possibility of an occasional excursion above 400 kW due to better than usual tuning in one of the machines upstream of the NuMI beam line. An excursion above the DOE approved Safety Envelope will constitute a safety violation. The purpose of this addendum is to evaluate the radiological issues and modifications required to operate the NuMI beam line at 500 kW. This upgrade will allow 400 kW operations with a reasonable safety margin. Configuration of the NuMI beam line, boundaries, safety system and the methodologies used for the calculations are as described in the original NuMI SAD. While most of the calculations presented in the original shielding assessment were based on Monte Carlo simulations, which were based on the design geometries, most of the results presented in this addendum are based on the measurements conducted by the AD ES&H radiation safety group.

  5. Recovery Act Workers Clear Reactor Shields from Brookhaven Lab

    Broader source: Energy.gov [DOE]

    American Recovery and Reinvestment Act workers are in the final stage of decommissioning a nuclear reactor after they recently removed thick steel shields once used to absorb neutrons produced for...

  6. Colorado's Economic Recovery since the Great Recession Professor Martin Shields

    E-Print Network [OSTI]

    1 Colorado's Economic Recovery since the Great Recession Professor Martin Shields Regional Economics Institute Colorado State University csurei, economic performance has been mixed. The northern Front Range has fared best

  7. RSMASS: A simple model for estimating reactor and shield masses

    SciTech Connect (OSTI)

    Marshall, A.C.; Aragon, J.; Gallup, D.

    1987-01-01T23:59:59.000Z

    A simple mathematical model (RSMASS) has been developed to provide rapid estimates of reactor and shield masses for space-based reactor power systems. Approximations are used rather than correlations or detailed calculations to estimate the reactor fuel mass and the masses of the moderator, structure, reflector, pressure vessel, miscellaneous components, and the reactor shield. The fuel mass is determined either by neutronics limits, thermal/hydraulic limits, or fuel damage limits, whichever yields the largest mass. RSMASS requires the reactor power and energy, 24 reactor parameters, and 20 shield parameters to be specified. This parametric approach should be applicable to a very broad range of reactor types. Reactor and shield masses calculated by RSMASS were found to be in good agreement with the masses obtained from detailed calculations.

  8. Criticality Evaluation - Cask Unloading Using the Shielded Transfer System

    SciTech Connect (OSTI)

    Blanchard, A. [Westinghouse Savannah River Company, AIKEN, SC (United States); Nadeau, M.L.

    1998-06-01T23:59:59.000Z

    This evaluation reviewed the criticality aspects of Shielded Transfer System (STS) operation. The existing Nuclear Safety Control (NSC) elements were examined and new NSC elements were developed, as needed.

  9. NASA TM-2012-217361 Evaluating Shielding Approaches to Reduce

    E-Print Network [OSTI]

    Rathbun, Julie A.

    Space Information 7121 Standard Hanover, MD 21076-1320 #12;NASA TM-2012-217361 Evaluating Shielding ApproachesSpace Information National Technical Information Service 7121 Standard Drive 5285 Port Royal Road Hanover, MD 21076

  10. Experimental Test of Self-Shielding in VUV Photodissociation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Experimental Test of Self-Shielding in VUV Photodissociation of CO Print One way to test models of the solar system's formation is to compare the isotopic abundances of the...

  11. A small satellite preliminary thermal control and heat shield analysis

    E-Print Network [OSTI]

    Melani Barreiro, Diego A

    2008-01-01T23:59:59.000Z

    As part of a student owned small satellite project, a preliminary thermal control and heat shield analysis was developed to verify acceptable performance requirements for the system. For the thermal control section, the ...

  12. Upgrade of the LHC magnet interconnections thermal shielding

    SciTech Connect (OSTI)

    Musso, Andrea; Barlow, Graeme; Bastard, Alain; Charrondiere, Maryline; Deferne, Guy; Dib, Gaëlle; Duret, Max; Guinchard, Michael; Prin, Hervé; Craen, Arnaud Vande; Villiger, Gilles [CERN European Organization for Nuclear Research, Meyrin 1211, Geneva 23, CH (Switzerland); Chrul, Anna [The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul.Radzikowskiego 152, 31-324 Krakow (Poland); Damianoglou, Dimitrios [NTUA National Technical University of Athens, Heeron Polytechniou 9, 15780 Zografou (Greece); Strychalski, Micha? [Wroclaw University of Technology, Faculty of Mechanical and Power Engineering, Wyb. Wyspianskiego 27, Wroclaw, 50-370 (Poland); Wright, Loren [Lancaster University, Bailrigg, Lancaster, LA1 4YW (United Kingdom)

    2014-01-29T23:59:59.000Z

    The about 1700 interconnections (ICs) between the Large Hadron Collider (LHC) superconducting magnets include thermal shielding at 50-75 K, providing continuity to the thermal shielding of the magnet cryostats to reduce the overall radiation heat loads to the 1.9 K helium bath of the magnets. The IC shield, made of aluminum, is conduction-cooled via a welded bridge to the thermal shield of the adjacent magnets which is actively cooled. TIG welding of these bridges made in the LHC tunnel at installation of the magnets induced a considerable risk of fire hazard due to the proximity of the multi-layer insulation of the magnet shields. A fire incident occurred in one of the machine sectors during machine installation, but fortunately with limited consequences thanks to prompt intervention of the operators. LHC is now undergoing a 2 years technical stop during which all magnet's ICs will have to be opened to consolidate the magnet electrical connections. The IC thermal shields will therefore have to be removed and re-installed after the work is completed. In order to eliminate the risk of fire hazard when re-welding, it has been decided to review the design of the IC shields, by replacing the welded bridges with a mechanical clamping which also preserves its thermal function. An additional advantage of this new solution is the ease in dismantling for maintenance, and eliminating weld-grinding operations at removal needing radioprotection measures because of material activation after long-term operation of the LHC. This paper describes the new design of the IC shields and in particular the theoretical and experimental validation of its thermal performance. Furthermore a status report of the on-going upgrade work in the LHC is given.

  13. Atom Interferometry

    ScienceCinema (OSTI)

    Mark Kasevich

    2010-01-08T23:59:59.000Z

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton?s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  14. Blue Cross Blue Shield of Massachusetts is an Independent Licensee of the Blue Cross and Blue Shield Association Expanded Coverage for Preventive Care Under

    E-Print Network [OSTI]

    Aalberts, Daniel P.

    Blue Cross Blue Shield of Massachusetts is an Independent Licensee of the Blue Cross and Blue. Effect the New Rules Will Have on Members and Accounts Blue Cross Blue Shield of Massachusetts. Blue Cross Blue Shield of Massachusetts will offer the following services with no member cost share

  15. SPAN-4. A Point-Kernel Shield Evaluation Code

    SciTech Connect (OSTI)

    Wallace, O.J. [Bettis Atomic Power Lab., West Mifflin, PA, (United States)

    1992-03-16T23:59:59.000Z

    SPAN4 calculates the fast neutron dose rate, thermal neutron flux, gamma-ray flux, dose rate, and energy-absorption rate in rectangular, cylindrical, and spherical geometries by integrating appropriate exponential kernels over a source distribution. The shield configuration is flexible, a first-level shield mesh, using any one of the three geometries, is specified. Regions of this same geometry or of other geometries, having their own (finer) meshes, may then be embedded between the first-level mesh lines, defining second-level shield meshes. This process is telescopic, third-level shield meshes may be embedded between second-level meshlines in turn. All meshes may have variable spacing. Sources and detectors may be located arbitrarily with respect to any shield mesh. The source is defined by the function: s=s0+s1(a)*s2(b)*s3(c)+s4(a,b)*s3(c)+s5(a,c)*s2(b)+s6(b,c) *s1(a)+s7(a,b,c), where a, b, and c represent coordinates. If any factor is missing, the corresponding terms are zero.

  16. Measuring Atomic Properties with an Atom Interferometer

    E-Print Network [OSTI]

    Roberts, Tony David

    2006-06-28T23:59:59.000Z

    Two experiments are presented which measure atomic properties using an atom interferometer. The interferometer splits the sodium de Broglie wave into two paths,

  17. Shielding analysis of the NAC-MPC storage system

    SciTech Connect (OSTI)

    Napolitano, D.G.; Romano, N.J. [NAC International, Norcross, GA (United States); Hertel, N.E. [Georgia Institute of Technology, Atlanta, GA (United States)] [and others

    1997-12-01T23:59:59.000Z

    This paper presents the shielding analyses of the NAC-MPC dry cask storage system. The NAC-MPC dry cask storage system consists of a transportable storage canister, a transfer cask, and a vertical concrete storage cask. The NAC-MPC is designed to accommodate 36 {open_quotes}Yankee Class{close_quotes} fuel assemblies with a maximum burnup of 36,000 MWd/tonne U burnup and 8 yr cooling time. The shielding analysis is performed with the SCALE 4.3 code package which includes SAS2H for source term generation and SAS4A, a modification of SAS4, for shielding evaluations. SAS4 utilizes a one-dimensional XSDRNPM adjoint calculation of the cask to generate biasing parameters for a three-dimensional MORSE-SGC Monte Carlo model of the cask geometry.

  18. Concrete Shield Performance of the VSC-17 Spent Nuclear Fuel Cask

    SciTech Connect (OSTI)

    Koji Shirai

    2006-04-01T23:59:59.000Z

    The VSC-17 Spent Nuclear Fuel Storage Cask was surveyed for degradation of the concrete shield by radiation measurement, temperature measurement, and ultrasonic testing. No general loss of shielding function was identified.

  19. Application of plasma shield technology to the reduction, treatment, and disposal of hazardous organic and/or mixed wastes with actinide recovery

    SciTech Connect (OSTI)

    Adams, B.T.; Vaughan, L.L.; Joyce, E.L. Jr.; Bieniewski, T.M.

    1990-01-01T23:59:59.000Z

    Los Alamos research activities are currently directed at the application of the shielded hydrogen plasma torch to the direct production of actinide metals from a UF{sub 6} feedstock. Two broad classes of thermal plasma reactors are currently in widespread use: the direct current (dc) arc jet system and the radio frequency (rf) inductively coupled system. Los Alamos has improved upon the basic rf plasma tube design using the concept of a transformer. The unique feature of the Los Alamos tube is a segmented, cooled, internal radiation shield. The Los Alamos shielded plasma torch routinely achieves temperatures exceeding 10,000 K and electron densities of 10{sup 16}/cm{sup 3} when operated continuously at one atmosphere of argon. These highly energetic conditions are sufficient to dissociate most chemical compounds into their constituent atoms. Based upon these characteristics, Los Alamos is currently investigating the application of the shielded plasma torch technology to the destruction of organic and mixed hazardous wastes, as well as the direct production of actinide metals from the halides and oxides, without the cogeneration of contaminated wastes. 5 refs., 4 figs.

  20. Multi electron species and shielding potentials in plasmas

    SciTech Connect (OSTI)

    Khan, Arroj A.; Murtaza, G. [Salam Chair in Physics, Government College University, Lahore 54000 (Pakistan); Rasheed, A.; Jamil, M. [Department of Physics, Government College University, Faisalabad 38000 (Pakistan)

    2012-11-15T23:59:59.000Z

    The phenomenon of Debye shielding is investigated in electron ion plasmas using the approach of two temperature electrons. We get different profiles of potential for different parameters and observe that the potentials fall very slowly than the standard Coulomb and Debye potentials. The importance of work is pointed out in the introduction.

  1. RSMASS-D: Reactor and shield mass minimization models

    SciTech Connect (OSTI)

    Marshall, A.C. (Department 0410 Sandia National Laboratories (USA) NE-52 The Department of Energy, Germantown Building, Washington, D.C. 20545 (USA)); Gallup, D.R. (Division 6472 Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (USA))

    1991-01-01T23:59:59.000Z

    Three relatively simple mathematical models have been developed to estimate minimum reactor and radiation shield masses for liquid metal cooled reactors (LMR's), in-core thermionic reactors (TI's) and out-of-core thermionic reactors (OTR's). The approach was based on much of the methodology developed for the RSMASS model (Marshall 1986). The models use a combination of simple equations derived from reactor physics and other fundamental considerations along with tabulations of data from more detailed neutron and gamma transport theory computations. All three models vary basic design parameters within an allowed range to achieve a parameter choice which yields a minimum mass for the power level and operational time of interest. The impact of critical mass, fuel damage and thermal limitations are accounted for in the computations. Thermionic requirements are also accounted for in the thermionic reactor models. All major reactor component masses are estimated as well as instrumentation and control (I C), boom and safety system mass. A new shield model was developed and incorporated into all three models. The new shield model is more accurate and simpler to use than the approach used in the original RSMASS model. The estimated reactor and shield masses agree with the mass predictions from detailed calculations within 16 percent for all three models.

  2. RZ calculations for self shielded multigroup cross sections

    SciTech Connect (OSTI)

    Li, M.; Sanchez, R.; Zmijarevic, I.; Stankovski, Z. [Commissariat a l'Energie Atomique CEA, Direction de l'Energie Nucleaire, DEN/DM2S/SERMA/LENR, 91191 Gif-sur-Yvette Cedex (France)

    2006-07-01T23:59:59.000Z

    A collision probability method has been implemented for RZ geometries. The method accounts for white albedo, specular and translation boundary condition on the top and bottom surfaces of the geometry and for a white albedo condition on the outer radial surface. We have applied the RZ CP method to the calculation of multigroup self shielded cross sections for Gadolinia absorbers in BWRs. (authors)

  3. aircraft shield test reactor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    aircraft shield test reactor First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Experimental Tests of...

  4. aperture shield materials: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    aperture shield materials First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Light-weight Flexible...

  5. Advances in Magnetized Plasma Propulsion and Radiation Shielding Robert Winglee

    E-Print Network [OSTI]

    Shepherd, Simon

    Advances in Magnetized Plasma Propulsion and Radiation Shielding Robert Winglee Department of Earth Propulsion (M2P2)3,4 . In this scheme a magnetic field attached to the spacecraft is expanded-mangetosphere, that is magnetic field inflated by the injection of plasma have several applications key to the exploration

  6. analytic shielding optimization: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    analytic shielding optimization First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Information Management,...

  7. Atomic magnetometer

    DOE Patents [OSTI]

    Schwindt, Peter (Albuquerque, NM); Johnson, Cort N. (Albuquerque, NM)

    2012-07-03T23:59:59.000Z

    An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

  8. Depleted uranium hexafluoride: The source material for advanced shielding systems

    SciTech Connect (OSTI)

    Quapp, W.J.; Lessing, P.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Cooley, C.R. [Department of Technology, Germantown, MD (United States)

    1997-02-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) has a management challenge and financial liability problem in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF{sub 6}) that are stored at the gaseous diffusion plants. DOE is evaluating several options for the disposition of this UF{sub 6}, including continued storage, disposal, and recycle into a product. Based on studies conducted to date, the most feasible recycle option for the depleted uranium is shielding in low-level waste, spent nuclear fuel, or vitrified high-level waste containers. Estimates for the cost of disposal, using existing technologies, range between $3.8 and $11.3 billion depending on factors such as the disposal site and the applicability of the Resource Conservation and Recovery Act (RCRA). Advanced technologies can reduce these costs, but UF{sub 6} disposal still represents large future costs. This paper describes an application for depleted uranium in which depleted uranium hexafluoride is converted into an oxide and then into a heavy aggregate. The heavy uranium aggregate is combined with conventional concrete materials to form an ultra high density concrete, DUCRETE, weighing more than 400 lb/ft{sup 3}. DUCRETE can be used as shielding in spent nuclear fuel/high-level waste casks at a cost comparable to the lower of the disposal cost estimates. Consequently, the case can be made that DUCRETE shielded casks are an alternative to disposal. In this case, a beneficial long term solution is attained for much less than the combined cost of independently providing shielded casks and disposing of the depleted uranium. Furthermore, if disposal is avoided, the political problems associated with selection of a disposal location are also avoided. Other studies have also shown cost benefits for low level waste shielded disposal containers.

  9. Blue Shield ensures uninterrupted access to quality medical care after Palm Drive Hospital ceases operations

    E-Print Network [OSTI]

    Ravikumar, B.

    Blue Shield ensures uninterrupted access to quality medical care after Palm Drive Hospital ceases and inpatient services due to the hospital's bankruptcy filing. This closure affects Blue Shield HMO plan members who have been utilizing Palm Drive Hospital services. Please be advised that Blue Shield

  10. Company Name: Blue Cross Blue Shield of MA Web Site: www.bluecrossma.com

    E-Print Network [OSTI]

    New Hampshire, University of

    Company Name: Blue Cross Blue Shield of MA Web Site: www.bluecrossma.com Industry: Healthcare Brief Company Overview: Headquartered in Boston, Blue Cross Blue Shield of Massachusetts provides comprehensive-level position: Please visit www.bluecrossma.com/careers. With almost 3 million members, Blue Cross Blue Shield

  11. Colorado Supplement to the Summary of Benefits and Coverage Form Anthem Blue Cross and Blue Shield

    E-Print Network [OSTI]

    Supplement to the Summary of Benefits and Coverage Form Anthem Blue Cross and Blue Shield CHEIBA Prime PPO Screenings, Prostate Cancer Screenings, and Colorectal Cancer Screenings. Anthem Blue Cross and Blue Shield Colorado, Inc. Independent licensees of the Blue Cross and Blue Shield Association. ®ANTHEM is a registered

  12. Colorado Supplement to the Summary of Benefits and Coverage Form Anthem Blue Cross and Blue Shield

    E-Print Network [OSTI]

    Supplement to the Summary of Benefits and Coverage Form Anthem Blue Cross and Blue Shield CHEIBA Custom Plus Screenings, Prostate Cancer Screenings, and Colorectal Cancer Screenings. Anthem Blue Cross and Blue Shield Colorado, Inc. Independent licensees of the Blue Cross and Blue Shield Association. ®ANTHEM is a registered

  13. Flood and Shield Basalts from Ethiopia: Magmas from the African Superswell

    E-Print Network [OSTI]

    Demouchy, Sylvie

    Flood and Shield Basalts from Ethiopia: Magmas from the African Superswell BRUNO KIEFFER1, ETHIOPIA 4 DEEPARTEMENT DES SCIENCES DE LA TERRE ET DE L'ENVIRONNEMENT, UNIVERSITEE LIBRE DE BRUXELLES 50 the shield volcanoes. KEY WORDS: Ethiopia; flood basalts; shield volcanism; superswell INTRODUCTION According

  14. A low-noise ferrite magnetic shield T. W. Kornack,a

    E-Print Network [OSTI]

    Romalis, Mike

    A low-noise ferrite magnetic shield T. W. Kornack,a S. J. Smullin, S.-K. Lee, and M. V. Romalis April 2007; published online 29 May 2007 Ferrite materials provide magnetic shielding performance by thermal Johnson currents due to their high electrical resistivity. Measurements inside a ferrite shield

  15. Terrestrial Background Reduction in RPM Systems by Direct Internal Shielding

    SciTech Connect (OSTI)

    Robinson, Sean M.; Ashbaker, Eric D.; Schweppe, John E.

    2008-11-19T23:59:59.000Z

    Gamma-ray detection systems that are close to the earth or other sources of background radiation often require shielding, especially when trying to detect a relatively weak source. One particular case of interest that we address in this paper is that encountered by the Radiation Portal Monitors (RPMs) systems placed at border-crossing Ports of Entry (POE). These RPM systems are used to screen for illicit radiological materials, and they are often placed in situations where terrestrial background is large. In such environments, it is desirable to consider simple physical modifications that could be implemented to reduce the effects from background radiation without affecting the flow of traffic and the normal operation of the portal. Simple modifications include adding additional shielding to the environment, either inside or outside the apparatus. Previous work [2] has shown the utility of some of these shielding configurations for increasing the Signal to Noise Ratio (SNR) of gross-counting RPMs. Because the total cost for purchasing and installing RPM systems can be quite expensive, in the range of hundreds of thousands of dollars for each cargo-screening installation, these shielding variations may offer increases in detection capability for relatively small cost. Several modifications are considered here in regard to their real-world applicability, and are meant to give a general idea of the effectiveness of the schemes used to reduce background for both gross-counting and spectroscopic detectors. These scenarios are modeled via the Monte-Carlo N-Particle (MCNP) code package [1] for ease of altering shielding configurations, as well as enacting unusual scenarios prior to prototyping in the field. The objective of this paper is to provide results representative of real modifications that could enhance the sensitivity of this, as well as the next generation of radiation detectors. The models used in this work were designed to provide the most general results for an RPM. These results are therefore presented as general guidance on what shielding configurations will be the most valuable for a generalized RPM, considered in light of their economic and geometric possibility in the real world.

  16. Field corrosion testing and performance of cable shielding materials in soils

    SciTech Connect (OSTI)

    Haynes, G.; Baboian, R. (Texas Instruments Inc., Electrochemical and Corrosion Lab., 34 Forest St., Mail Station 10-13, Attleboro, MA (US))

    1989-09-01T23:59:59.000Z

    This article discusses the importance of corrosion resistance in cable-shielding materials, describes the mechanisms of shielding corrosion that occur in buried telephone cable, and evaluates the results of the six-year REA Horry Cooperative buried telephone cable corrosion test. In this study, both active and static cables were included. Withdrawals were made over a six-year period. These cables were evaluated for cable-shielding corrosion. Special attention was paid to the comparative behavior of active and static cables. Results indicate that steel shieldings are most susceptible to the effects of alternating current (AC) in active cables. Results of a wide range of shieldings are presented and evaluated.

  17. Shielding of absorbing objects in collisionless flowing plasma

    E-Print Network [OSTI]

    Tyshetskiy, Yuriy

    2010-01-01T23:59:59.000Z

    The electrostatic shielding of a charged absorbing object (dust grain) in a flowing collisionless plasma is investigated by using the linearized kinetic equation for plasma ions with a point-sink term accounting for ion absorption on the object. The effect of absorption on the attractive part of the grain potential is investigated. For subthermal ion flows, the attractive part of the grain potential in the direction perpendicular to the ion flow can be significantly reduced or completely destroyed, depending on the absorption rate. For superthermal ion flows, however, the effect of absorption on the grain attraction in the direction perpendicular to the ion flow is shown to be exponentially weak. It is thus argued that, in the limit of superthermal ion flow, the effect of absorption on the grain shielding potential can be safely ignored for typical grain sizes relevant to complex plasmas.

  18. Secret key distillation from shielded two-qubit states

    E-Print Network [OSTI]

    Joonwoo Bae

    2010-09-22T23:59:59.000Z

    The quantum states corresponding to a secret key are characterized using the so-called private states, where the key part consisting of a secret key is shielded by the additional systems. Based on the construction, it was shown that a secret key can be distilled from bound entangled states. In this work, I consider the shielded two-qubit states in a key-distillation scenario and derive the conditions under which a secret key can be distilled using the recurrence protocol or the two-way classical distillation, advantage distillation together with one-way postprocessing. From the security conditions, it is shown that a secret key can be distilled from bound entangled states in a much wider range. In addition, I consider the case that in which white noise is added to quantum states and show that the classical distillation protocol still works despite a certain amount of noise although the recurrence protocol does not.

  19. Resonance self-shielding effects on Eigenvalue sensitivity

    SciTech Connect (OSTI)

    Dion, M.; Marleau, G. [Ecole Polytechnique de Montreal, Institut de Genie Nucleaire, C.P. 6079, suce. Centre-ville, Montreal, QC H3C 3A7 (Canada)

    2013-07-01T23:59:59.000Z

    We present a quick and accurate way to compute the eigenvalue sensitivity coefficients in multigroup lattice cell calculations. We look at both the explicit and implicit sensitivities, the latter resulting from the resonance self-shielding process. A self-shielding model is presented, and we show how to obtain cross section sensitivities to a variation on a light isotope density. As an example, we look at how a perturbation on the hydrogen density affects the multigroup cross sections for resonant reactions such as U'capture and U'fission, in two uranium spheres with different enrichments. Explicit sensitivities are also computed, and we discuss the relative importance of the implicit sensitivities. (authors)

  20. Superconducting shielded core reactor with reduced AC losses

    DOE Patents [OSTI]

    Cha, Yung S.; Hull, John R.

    2006-04-04T23:59:59.000Z

    A superconducting shielded core reactor (SSCR) operates as a passive device for limiting excessive AC current in a circuit operating at a high power level under a fault condition such as shorting. The SSCR includes a ferromagnetic core which may be either closed or open (with an air gap) and extends into and through a superconducting tube or superconducting rings arranged in a stacked array. First and second series connected copper coils each disposed about a portion of the iron core are connected to the circuit to be protected and are respectively wound inside and outside of the superconducting tube or rings. A large impedance is inserted into the circuit by the core when the shielding capability of the superconducting arrangement is exceeded by the applied magnetic field generated by the two coils under a fault condition to limit the AC current in the circuit. The proposed SSCR also affords reduced AC loss compared to conventional SSCRs under continuous normal operation.

  1. Secret key distillation from shielded two-qubit states

    SciTech Connect (OSTI)

    Bae, Joonwoo [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)

    2010-05-15T23:59:59.000Z

    The quantum states corresponding to a secret key are characterized using the so-called private states, where the key part consisting of a secret key is shielded by the additional systems. Based on the construction, it was shown that a secret key can be distilled from bound entangled states. In this work, I consider the shielded two-qubit states in a key-distillation scenario and derive the conditions under which a secret key can be distilled using the recurrence protocol or the two-way classical distillation, advantage distillation together with one-way postprocessing. From the security conditions, it is shown that a secret key can be distilled from bound entangled states in a much wider range. In addition, I consider the case that in which white noise is added to quantum states and show that the classical distillation protocol still works despite a certain amount of noise although the recurrence protocol does not.

  2. Accordian-folded boot shield for flexible swivel connection

    DOE Patents [OSTI]

    Hoh, Joseph C. (Naperville, IL)

    1986-01-01T23:59:59.000Z

    A flexible swivel boot connector for connecting a first boot shield section to a second boot shield section, both first and second boot sections having openings therethrough, the second boot section having at least two adjacent accordian folds at the end having the opening, the second boot section being positioned through the opening of the first boot section such that a first of the accordian folds is within the first boot section and a second of the accordian folds is outside of the first boot, includes first and second annular discs, the first disc being positioned within and across the first accordian fold, the second disc being positioned within and across the second accordian fold, such that the first boot section is moveably and rigidly connected between the first and second accordian folds of the second boot section.

  3. Attenuation of high-energy x rays by iron shielding

    SciTech Connect (OSTI)

    Bespalov, V.I.; Chakhlov, V.L.; Shtein, M.M.

    1988-04-01T23:59:59.000Z

    Monte Carlo calculations are presented on electron-accelerator x-ray spectra for actual target thicknesses and electron energies of 4-50 MeV. Effective attenuation coefficients have been obtained as well as build-up factors for collimated beams andiron shielding of thickness form 1 to 80 cm. The radiation contrast has been determined as a function of thickness for this energy range.

  4. Propellantless propulsion in magnetic fields by partially shielded current

    E-Print Network [OSTI]

    Bergamin, L; Pinchook, A

    2006-01-01T23:59:59.000Z

    A new device for propellantless propulsion in presence of a magnetic field is discussed. The functional principle shares some features with electrodynamic tethers. However, the tether structure is replaced by a closed wire, which is partially shielded from the magnetic field by means of a superconductor. Therefore, it does not depend on the presence of a plasma. We show that even a relatively small device can yield interesting propulsivet forces for drag compensation or for orbital transfers.

  5. Magnetic shielding of Hall thrusters at high discharge voltages

    SciTech Connect (OSTI)

    Mikellides, Ioannis G., E-mail: Ioannis.G.Mikellides@jpl.nasa.gov; Hofer, Richard R.; Katz, Ira; Goebel, Dan M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-08-07T23:59:59.000Z

    A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700?V (I{sub sp}???2000–2700?s) at 6?kW, and 800?V (I{sub sp} ? 3000) at 9?kW. At 6?kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300?V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed maximum erosion rates in the range of 300–700?V are found not to exceed 10{sup ?2}?mm/kh. Such rates are ?3 orders of magnitude less than those observed in the unshielded version of the same thruster at 300?V. At 9?kW and 800?V, saturation of the magnetic circuit did not allow for precisely the same magnetic shielding topology as that employed during the 6-kW operation since this thruster was not designed to operate at this condition. Consequently, the maximum erosion rate at the inner wall is found to be ?1 order of magnitude higher (?10{sup ?1}?mm/kh) than that at 6?kW. At the outer wall, the ion energy is found to be below the sputtering yield threshold so no measurable erosion is expected.

  6. Blue Cross and Blue Shield of Florida is now Florida Blue State Employees' PPO Plan health insurance provider Blue Cross and Blue Shield of

    E-Print Network [OSTI]

    Ronquist, Fredrik

    Blue Cross and Blue Shield of Florida is now Florida Blue State Employees' PPO Plan health insurance provider Blue Cross and Blue Shield of Florida has recently changed its name to Florida Blue Resources Benefits Office at (850) 6444015, or insben@admin.fsu.edu. RELATED LINKS ­ Florida Blue

  7. atom-atom collisions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Safronova, Marianna 3 Atom-atom correlations in colliding Bose-Einstein condensates Quantum Physics (arXiv) Summary: We analyze atom-atom correlations in the s-wave...

  8. Benchmarking FENDL libraries through analysis of bulk shielding experiments on large SS316 assemblies for verification of ITER shielding characteristics

    SciTech Connect (OSTI)

    Youssef, M.Z.; Kumar, A.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States); Konno, Chikara; Maekawa, Fujio; Wada, Masayuki; Oyama, Yukio; Maekawa, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Ibaraki (Japan)

    1996-12-31T23:59:59.000Z

    FENDL-1 data base has been developed recently for use in ITER/EDA phase and other fusion-related design activities. It is now undergoing extensive testing and benchmarking using experimental data of differential and integral measured parameters obtained from fusion-oriented experiments. As part of co-operation between UCLA (U.S.) with JAERI (Japan) on executing the required neutronics R&D tasks for ITER shield design, two bulk shielding experiments on large SS316 assemblies were selected for benchmarking FENDL/MG-1 multigroup data base and FENDL/MC-1 continous energy data base. The analyses with the multigroup data (performed with S8, P5, DORT calculations with shielded and unshielded data) also included library derived from ENDF/B-VI data base for comparison purposes. The MCNP Monte Carlo code was used by JAERI with the FENDL/MC-1 data. The results of this benchmarking is reported in this paper along with the observed deficiencies and discrepancies. 20 refs., 27 figs., 1 tab.

  9. Scalar relativistic computations of nuclear magnetic shielding and g-shifts with the zeroth-order regular approximation and range-separated hybrid density functionals

    SciTech Connect (OSTI)

    Aquino, Fredy W.; Govind, Niranjan; Autschbach, Jochen

    2011-10-01T23:59:59.000Z

    Density functional theory (DFT) calculations of NMR chemical shifts and molecular g-tensors with Gaussian-type orbitals are implemented via second-order energy derivatives within the scalar relativistic zeroth order regular approximation (ZORA) framework. Nonhybrid functionals, standard (global) hybrids, and range-separated (Coulomb-attenuated, long-range corrected) hybrid functionals are tested. Origin invariance of the results is ensured by use of gauge-including atomic orbital (GIAO) basis functions. The new implementation in the NWChem quantum chemistry package is verified by calculations of nuclear shielding constants for the heavy atoms in HX (X=F, Cl, Br, I, At) and H2X (X = O, S, Se, Te, Po), and Te chemical shifts in a number of tellurium compounds. The basis set and functional dependence of g-shifts is investigated for 14 radicals with light and heavy atoms. The problem of accurately predicting F NMR shielding in UF6-nCln, n = 1 to 6, is revisited. The results are sensitive to approximations in the density functionals, indicating a delicate balance of DFT self-interaction vs. correlation. For the uranium halides, the results with the range-separated functionals are mixed.

  10. New Six-Layer Magnetically-Shielded Room for MEG D. Cohen1,2

    E-Print Network [OSTI]

    by Imedco, to house a 4-D MEG system, containing both gradiometers and magnetometers (Vectorview of the passive shielding factor yield 1,630 (64dB), 3,600 (71dB), 240,000 (107dB) , and 78,000,000 (158d of 0.010 to 0.10 Hz. The 78 dB was to combine 58 dB of passive shielding with 20 dB of active shielding

  11. Design and Testing of Improved Spacesuit Shielding Components

    SciTech Connect (OSTI)

    Ware, J.; Ferl, J.; Wilson, J.W.; Clowdsley, M.S.; DeAngelis, G.; Tweed, J.; Zeitlin, C.J.

    2002-05-08T23:59:59.000Z

    In prior studies of the current Shuttle Spacesuit (SSA), where basic fabric lay-ups were tested for shielding capabilities, it was found that the fabric portions of the suit give far less protection than previously estimated due to porosity and non-uniformity of fabric and LCVG components. In addition, overall material transmission properties were less than optimum. A number of alternate approaches are being tested to provide more uniform coverage and to use more efficient materials. We will discuss in this paper, recent testing of new material lay-ups/configurations for possible use in future spacesuit designs.

  12. Dose estimates in a loss of lead shielding truck accident.

    SciTech Connect (OSTI)

    Dennis, Matthew L.; Osborn, Douglas M.; Weiner, Ruth F.; Heames, Terence John (Alion Science & Technology Albuquerque, NM)

    2009-08-01T23:59:59.000Z

    The radiological transportation risk & consequence program, RADTRAN, has recently added an updated loss of lead shielding (LOS) model to it most recent version, RADTRAN 6.0. The LOS model was used to determine dose estimates to first-responders during a spent nuclear fuel transportation accident. Results varied according to the following: type of accident scenario, percent of lead slump, distance to shipment, and time spent in the area. This document presents a method of creating dose estimates for first-responders using RADTRAN with potential accident scenarios. This may be of particular interest in the event of high speed accidents or fires involving cask punctures.

  13. Fabrication options for depleted uranium components in shielded containers

    SciTech Connect (OSTI)

    Derrington, S.B.; Thompson, J.E.; Coates, C.W.

    1994-01-27T23:59:59.000Z

    Depleted uranium (DU) is an attractive material for the gamma-shielding components in containers designed for the storage, transport, and disposal of high-level radioactive wastes or spent nuclear fuel. The size and weight of these components present fabrication challenges. A broad range of technical expertise, capabilities, and facilities for uranium manufacturing and technology development exist at the Department of Energy laboratories and production facilities and within commercial industry. Several cast and wrought processes are available to fabricate the DU components. Integration of the DU fabrication capabilities and physical limitations for handling the DU components into the early design phase will ensure a fabricable product.

  14. Early Test Facilities and Analytic Methods for Radiation Shielding

    SciTech Connect (OSTI)

    Ingersoll, D.T.

    1992-01-01T23:59:59.000Z

    This report represents a compilation of eight papers presented at the 1992 American Nuclear Society/European Nuclear Society International Meeting held in Chicago, Illinois on November 15 20,1992. The meeting is of special significance since it commemorates the 50th anniversary of the first controlled nuclear chain reaction, which occurred, not coincidentally, in Chicago. The papers contained in this report were presented in a special session organized by the Radiation Protection and Shielding Division in keeping with the historical theme of the meeting.

  15. Brachytherapy structural shielding calculations using Monte Carlo generated, monoenergetic data

    SciTech Connect (OSTI)

    Zourari, K.; Peppa, V.; Papagiannis, P., E-mail: ppapagi@phys.uoa.gr [Medical Physics Laboratory, Medical School, University of Athens, 75 Mikras Asias, 11527 Athens (Greece); Ballester, Facundo [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain)] [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Siebert, Frank-André [Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel 24105 (Germany)] [Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel 24105 (Germany)

    2014-04-15T23:59:59.000Z

    Purpose: To provide a method for calculating the transmission of any broad photon beam with a known energy spectrum in the range of 20–1090 keV, through concrete and lead, based on the superposition of corresponding monoenergetic data obtained from Monte Carlo simulation. Methods: MCNP5 was used to calculate broad photon beam transmission data through varying thickness of lead and concrete, for monoenergetic point sources of energy in the range pertinent to brachytherapy (20–1090 keV, in 10 keV intervals). The three parameter empirical model introduced byArcher et al. [“Diagnostic x-ray shielding design based on an empirical model of photon attenuation,” Health Phys. 44, 507–517 (1983)] was used to describe the transmission curve for each of the 216 energy-material combinations. These three parameters, and hence the transmission curve, for any polyenergetic spectrum can then be obtained by superposition along the lines of Kharrati et al. [“Monte Carlo simulation of x-ray buildup factors of lead and its applications in shielding of diagnostic x-ray facilities,” Med. Phys. 34, 1398–1404 (2007)]. A simple program, incorporating a graphical user interface, was developed to facilitate the superposition of monoenergetic data, the graphical and tabular display of broad photon beam transmission curves, and the calculation of material thickness required for a given transmission from these curves. Results: Polyenergetic broad photon beam transmission curves of this work, calculated from the superposition of monoenergetic data, are compared to corresponding results in the literature. A good agreement is observed with results in the literature obtained from Monte Carlo simulations for the photon spectra emitted from bare point sources of various radionuclides. Differences are observed with corresponding results in the literature for x-ray spectra at various tube potentials, mainly due to the different broad beam conditions or x-ray spectra assumed. Conclusions: The data of this work allow for the accurate calculation of structural shielding thickness, taking into account the spectral variation with shield thickness, and broad beam conditions, in a realistic geometry. The simplicity of calculations also obviates the need for the use of crude transmission data estimates such as the half and tenth value layer indices. Although this study was primarily designed for brachytherapy, results might also be useful for radiology and nuclear medicine facility design, provided broad beam conditions apply.

  16. Experimental Evaluation of the Thermal Performance of a Water Shield for a Surface Power Reactor

    SciTech Connect (OSTI)

    Pearson, J. Boise; Stewart, Eric T. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Reid, Robert S. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States)

    2007-01-30T23:59:59.000Z

    Water based reactor shielding is being investigated for use on initial lunar surface power systems. A water shield may lower overall cost (as compared to development cost for other materials) and simplify operations in the setup and handling. The thermal hydraulic performance of the shield is of significant interest. The mechanism for transferring heat through the shield is natural convection. Natural convection in a 100 kWt lunar surface reactor shield design is evaluated with 2 kW power input to the water in the Water Shield Testbed (WST) at the NASA Marshall Space Flight Center. The experimental data from the WST is used to validate a CFD model. Performance of the water shield on the lunar surface is then predicted with a CFD model anchored to test data. The experiment had a maximum water temperature of 75 deg. C. The CFD model with 1/6-g predicts a maximum water temperature of 88 deg. C with the same heat load and external boundary conditions. This difference in maximum temperature does not greatly affect the structural design of the shield, and demonstrates that it may be possible to use water for a lunar reactor shield.

  17. Shielding optimization studies for the detector systems of the Superconducting Super Collider

    SciTech Connect (OSTI)

    Slater, C.O.; Lillie, R.A.; Gabriel, T.A.

    1994-09-01T23:59:59.000Z

    Preliminary shielding optimization studies for the Superconducting Super Collider`s Solenoidal Detector Collaboration detector system were performed at the Oak Ridge National Laboratory in 1993. The objective of the study was to reduce the neutron and gamma-ray fluxes leaving the shield to a level that resulted in insignificant effects on the functionality of the detector system. Steel and two types of concrete were considered as components of the shield, and the shield was optimized according to thickness, weight, and cost. Significant differences in the thicknesses, weights, and costs were noted for the three optimization parameters. Results from the study are presented.

  18. Structural Design and Thermal Analysis for Thermal Shields of the MICE Coupling Magnets

    SciTech Connect (OSTI)

    Green, Michael A.; Pan, Heng; Liu, X. K.; Wang, Li; Wu, Hong; Chen, A. B.; Guo, X.L.

    2009-07-01T23:59:59.000Z

    A superconducting coupling magnet made from copper matrix NbTi conductors operating at 4 K will be used in the Muon Ionization Cooling Experiment (MICE) to produce up to 2.6 T on the magnet centerline to keep the muon beam within the thin RF cavity indows. The coupling magnet is to be cooled by two cryocoolers with a total cooling capacity of 3 W at 4.2 K. In order to keep a certain operating temperature margin, the most important is to reduce the heat leakage imposed on cold surfaces of coil cold mass assembly. An ntermediate temperature shield system placed between the coupling coil and warm vacuum chamber is adopted. The shield system consists of upper neck shield, main shields, flexible connections and eight supports, which is to be cooled by the first stage cold heads of two ryocoolers with cooling capacity of 55 W at 60 K each. The maximum temperature difference on the shields should be less than 20 K, so the thermal analyses for the shields with different thicknesses, materials, flexible connections for shields' cooling and structure design for heir supports were carried out. 1100 Al is finally adopted and the maximum temperature difference is around 15 K with 4 mm shield thickness. The paper is to present detailed analyses on the shield system design.

  19. Instrumented, Shielded Test Canister System for Evaluation of Spent Nuclear Fuel in Dry Storage

    SciTech Connect (OSTI)

    Sindelar, R.L.

    1999-10-21T23:59:59.000Z

    This document describes the development of an instrumented, shielded test canister system to store and monitor aluminum-based spent nuclear duel under dry storage conditions.

  20. Nitrogen containing shielding gases for GTAW duplex stainless steels

    SciTech Connect (OSTI)

    Creffield, G.K.; Cole, M.H.; Paciej, R.; Huang, W.; Urmston, S. [BOC Ltd., London (United Kingdom)

    1993-12-31T23:59:59.000Z

    The duplex stainless steel are alloys characterized as consisting of two phases; austenite and ferrite. As such, they combine the benefits of both phases i.e. good ductility and general corrosion resistance of austenite, but with improved stress corrosion cracking resistance and strength associate with ferrite. Carefully controlled manufacturing techniques are employed to produce this combination in roughly equal proportions to ensure optimum properties. The range of duplex alloys studied in this work covered both the standard grade (2205) and the latest generation of super duplex (2507) alloys; typical compositions are shown in Table 1. Although the standard duplex is the most commonly available and widely used, super duplexes, which are characterized by higher chromium, nickel, molybdenum and nitrogen contents, have even better corrosion properties and are finding increasing applications in the offshore industry. To benefit from the superior properties of duplex, it is vital that these alloys can be welded effectively and that the properties of the welded joint match those of the parent weld. The objective of the current investigation was to study the effect of nitrogen, in both the shielding and purge gas, on the weld metal nitrogen content, microstructure and corrosion resistance, with the eventual aim of recommending an effective shielding gas mixture for duplex stainless steels.

  1. Magnetic shielding of a laboratory Hall thruster. II. Experiments

    SciTech Connect (OSTI)

    Hofer, Richard R., E-mail: richard.r.hofer@jpl.nasa.gov; Goebel, Dan M.; Mikellides, Ioannis G.; Katz, Ira [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

    2014-01-28T23:59:59.000Z

    The physics of magnetic shielding in Hall thrusters were validated through laboratory experiments demonstrating essentially erosionless, high-performance operation. The magnetic field near the walls of a laboratory Hall thruster was modified to effectively eliminate wall erosion while maintaining the magnetic field topology away from the walls necessary to retain efficient operation. Plasma measurements at the walls validate our understanding of magnetic shielding as derived from the theory. The plasma potential was maintained very near the anode potential, the electron temperature was reduced by a factor of two to three, and the ion current density was reduced by at least a factor of two. Measurements of the carbon backsputter rate, wall geometry, and direct measurement of plasma properties at the wall indicate that the wall erosion rate was reduced by a factor of 1000 relative to the unshielded thruster. These changes effectively eliminate wall erosion as a life limitation in Hall thrusters, enabling a new class of deep-space missions that could not previously be attempted.

  2. Atomizing nozzle and process

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

    1993-07-20T23:59:59.000Z

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  3. Atomic swelling upon compression

    E-Print Network [OSTI]

    V. K. Dolmatov; J. L. King

    2012-08-18T23:59:59.000Z

    The hydrogen atom under the pressure of a spherical penetrable confinement potential of a decreasing radius $r_{0}$ is explored, as a case study. A novel counter-intuitive effect of atomic swelling rather than shrinking with decreasing $r_{0}$ is unraveled, when $r_{0}$ reaches, and remains smaller than, a certain critical value. Upon swelling, the size of the atom is shown to increase by an order of magnitude, or more, compared to the size of the free atom. Examples of changes of photoabsorption properties of confined hydrogen atom upon its swelling are uncovered and demonstrated.

  4. Colorado Supplement to the Summary of Benefits and Coverage Form Anthem Blue Cross and Blue Shield

    E-Print Network [OSTI]

    Supplement to the Summary of Benefits and Coverage Form Anthem Blue Cross and Blue Shield CHEIBA HMO/POS Plan. Anthem Blue Cross and Blue Shield is the trade name of Rocky Mountain Hospital and Medical Service, Inc. HMO products underwritten by HMO Colorado, Inc. Independent licensees of the Blue Cross and Blue

  5. Electric field gradient, generalized Sternheimer shieldings and electric field gradient polarizabilities by multiconfigurational SCF response

    E-Print Network [OSTI]

    Helgaker, Trygve

    Electric field gradient, generalized Sternheimer shieldings and electric field gradient at the nuclei, the generalized Sternheimer shielding constants and the EFG electric dipole polarizabilities discussed by Egstro¨m and co-workers4 and recently in a more general way by Fowler and co-workers.5

  6. Combined Use of Magnetic and Electrically Conductive Fillers in a Polymer Matrix for Electromagnetic Interference Shielding

    E-Print Network [OSTI]

    Chung, Deborah D.L.

    by radiofrequency radiation (such as that emitted by a cellular phone), there is a growing need for devel- oping) shielding refers to the blocking of electromagnetic radiation so that the radiation essentially cannot pass conductors such as met- als and carbons mainly shield by reflection of the radiation. On the other hand

  7. PHYSICS DIVISION ESH BULLETIN 2004-02 1/15/04 LEAD SHIELDING

    E-Print Network [OSTI]

    PHYSICS DIVISION ESH BULLETIN 2004-02 1/15/04 LEAD SHIELDING Lead bricks (also sheet, tape, shot) are commonly used in the Physics Division for radiation shielding. Lead is toxic by inhalation and ingestion. Lead is a carcinogen and a reproductive hazard for both males and females. In addition to being

  8. Shielding-Effectiveness Modeling of Carbon-Fiber/Nylon-6,6 Composites

    E-Print Network [OSTI]

    Perger, Warren F.

    - proving the electrical conductivity of a polymer is the addition of a conductive filler materialShielding-Effectiveness Modeling of Carbon-Fiber/Nylon- 6,6 Composites Nicholas B. Janda,1 Jason M a linear theory for the shielding effectiveness of composite matrix materials and have tested the theory

  9. Overlap Technique for End-Cap Seals on Cylindrical Magnetic Shields

    E-Print Network [OSTI]

    Malkowski, S; Boissevain, J; Daurer, C; Filippone, B W; Hona, B; Plaster, B; Woods, D; Yan, H

    2013-01-01T23:59:59.000Z

    We present results from studies of the effectiveness of an overlap technique for forming a magnetic seal across a gap at the boundary between a cylindrical magnetic shield and an end-cap. In this technique a thin foil of magnetic material overlaps the two surfaces, thereby spanning the gap across the cylinder and the end-cap, with the magnetic seal then formed by clamping the thin magnetic foil to the surfaces of the cylindrical shield and the end-cap on both sides of the gap. In studies with a prototype 31-cm diameter, 91-cm long, 0.16-cm thick cylindrical magnetic shield and flared end-cap, the magnetic shielding performance of our overlap technique is comparable to that obtained with the conventional method in which the end-cap is placed in direct lapped contact with the cylindrical shield via through bolts or screws.

  10. Estimation of the Performance of Multiple Active Neutron Interrogation Signatures for Detecting Shielded HEU

    SciTech Connect (OSTI)

    David L. Chichester; Scott J. Thompson; Scott M. Watson; James T. Johnson; Edward H. Seabury

    2012-10-01T23:59:59.000Z

    A comprehensive modeling study has been carried out to evaluate the utility of multiple active neutron interrogation signatures for detecting shielded highly enriched uranium (HEU). The modeling effort focused on varying HEU masses from 1 kg to 20 kg; varying types of shields including wood, steel, cement, polyethylene, and borated polyethylene; varying depths of the HEU in the shields, and varying engineered shields immediately surrounding the HEU including steel, tungsten, and cadmium. Neutron and gamma-ray signatures were the focus of the study and false negative detection probabilities versus measurement time were used as a performance metric. To facilitate comparisons among different approaches an automated method was developed to generate receiver operating characteristic (ROC) curves for different sets of model variables for multiple background count rate conditions. This paper summarizes results or the analysis, including laboratory benchmark comparisons between simulations and experiments. The important impact engineered shields can play towards degrading detectability and methods for mitigating this will be discussed.

  11. Earth pressure balance (EPB) shield tunneling in Bangkok : ground response and prediction of surface settlements using artificial neural networks

    E-Print Network [OSTI]

    Suwansawat, Suchatvee, 1972-

    2002-01-01T23:59:59.000Z

    Although Earth Pressure Balance (EPB) shields have been used for several decades, very little information exists about the actual mechanisms of shield-ground interaction. The ground response mechanism induced by EPB tunneling ...

  12. Method for fabricating fan-fold shielded electrical leads

    DOE Patents [OSTI]

    Rohatgi, R.R.; Cowan, T.E.

    1994-12-27T23:59:59.000Z

    Fan-folded electrical leads made from copper cladded Kapton, for example, with the copper cladding on one side serving as a ground plane and the copper cladding on the other side being etched to form the leads. The Kapton is fan folded with the leads located at the bottom of the fan-folds. Electrical connections are made by partially opening the folds of the fan and soldering, for example, the connections directly to the ground plane and/or the lead. The fan folded arrangement produces a number of advantages, such as electrically shielding the leads from the environment, is totally non-magnetic, and has a very low thermal conductivity, while being easy to fabricate. 3 figures.

  13. Underground barrier construction apparatus with soil-retaining shield

    DOE Patents [OSTI]

    Gardner, Bradley M. (Idaho Falls, ID); Smith, Ann Marie (Pocatello, ID); Hanson, Richard W. (Spokane, WA); Hodges, Richard T. (Deer Park, WA)

    1998-01-01T23:59:59.000Z

    An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

  14. Underground barrier construction apparatus with soil-retaining shield

    DOE Patents [OSTI]

    Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.

    1998-08-04T23:59:59.000Z

    An apparatus is described for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment. 17 figs.

  15. U. S. ITER shield and blanket design activities

    SciTech Connect (OSTI)

    Baker, C.C.

    1989-03-01T23:59:59.000Z

    This paper summarizes nuclear-related work in support of the U.S. effort for the Internatinoal Thermonuclear Experimental Reactor (ITER) Study. Primary tasks carried out during the past year include design improvements of the inboard shield developed for the TIBER concept, scoping studies of a variety of tritium breeding blanket options, development of necessary design guidelines and evaluation criteria for the blanket options, further safety considerations related to nuclear components, and issues regarding structural materials for an ITER device. The blanket concepts considered are the aqueous/Li salt solution, a water-cooled, solid-breeder blanket, a helium-cooled, solid-breeder blanket, a helium-cooled, solid-breeder blanket, a blanket cooled by helium containing lithium-bearing particulates, and a blanket concept based on breeding tritium from He/sup 3/.

  16. Reactor and shielding design implications of clustering nuclear thermal rockets

    SciTech Connect (OSTI)

    Buksa, J.J.; Houts, M.G. (Los Alamos National Laboratory, NM (United States))

    1992-07-01T23:59:59.000Z

    This paper examines design considerations in the context of engine-out accidents in clustered nuclear-thermal rocket stages, and an accident-management protocol is devised. Safety and performance issues are considered in the light of designs for the reactor and shielding elements of ROVER/NERVA-type engines. The engine-out management process involves: phase one, in which sufficient propulsive power is guaranteed for mission completion; and phase two, in which engine failure is isolated and not allowed to propagate to other engines or to the spacecraft. Phase-one designs can employ spare engines, throttled engines, and/or long-burning engines. Phase-two safety concepts can include techniques for cooling or jettisoning the failed engines. Engine-out management philosophies are shown to be shaped by a combination of safety and mission-trajectory requirements. 6 refs.

  17. Penetration of the LCLS Injector Shield Wall at Sector 20

    SciTech Connect (OSTI)

    Dowell, D

    2010-12-10T23:59:59.000Z

    Penetrations through the LCLS injector shield wall are needed for the alignment of the accelerator, a diagnostic laser beam and utilities, and are shown in figure 1. The 1-inch diameter LCLS injector beam tube is blocked by the PPS stopper when the injector side of the wall is occupied. The two 3-inch diameter penetrations above and to the left of the beam tube are used by Precision Alignment and will be open only during installation of the injector beamline. Additional 3-inch diameter penetrations are for laser beams which will be used for electron beam diagnostics. These will not be plugged when the injector occupied. Other penetrations for the RF waveguide and other utilities are approximately 13-inch from the floor and as such are far from the line-of-sight of any radiation sources. The waveguide and utility penetrations pass only through the thicker wall as shown in the figure. The principal issue is with the two laser penetrations, since these will be open when the linac is operating and people are in the LCLS injector area. A principal concern is radiation streaming through the penetrations due to direct line-of sight of the PEP-2 lines. To answer this, fans of rays were traced through the 3-inch diameter laser penetrations as shown in Figures 2 and 3. Figure 2 gives the top view of the shield walls, the main linac and PEP-2 lines, and the ray-fans. The fans appear to originate between the walls since their angular envelope is defined by the greatest angle possible when rays are just on the 3-inch diameter at the inner most and outermost wall surfaces. The crossovers of all possible rays lie half way between these two surfaces. As the end-on view of Figure 3 clearly shows, there is no direct line-of-sight through the laser penetrations of the PEP-2 or linac beamlines.

  18. 1370 Rev. (3/03) An independent licensee of the Blue Cross and Blue Shield Association. Anthem Blue Cross and Blue Shield is the trade name of Anthem Health Plans of New Hampshire, Inc.

    E-Print Network [OSTI]

    Myers, Lawrence C.

    1370 Rev. (3/03) An independent licensee of the Blue Cross and Blue Shield Association. Anthem Blue Cross and Blue Shield is the trade name of Anthem Health Plans of New Hampshire, Inc. ® Registered marks of the Blue Cross and Blue Shield Association. Request for Certification for a Mentally or Physically

  19. Final Technical Report [Cosmogenic background and shielding R&D for a Ge Neutrinoless Double Beta Decay Experiment

    SciTech Connect (OSTI)

    Guiseppe, Vince

    2013-10-01T23:59:59.000Z

    The USD Majorana group focused all of its effort in support of the MAJORANA DEMONSTRATOR (MJD) experiment. Final designs of the shielding subsystems are complete. Construction of the MJD shielding systems at SURF has begun and the proposed activities directly support the completion of the shield systems. The PI and the group contribute heavily to the onsite construction activities of the MJD experiment. The group led investigations into neutron and neutron-­?induced backgrounds, shielding effectiveness and design, and radon backgrounds.

  20. Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield inside them, according to a

    E-Print Network [OSTI]

    McDonald, Kirk

    Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield FOR A MUON COLLIDER (TUP265, PAC11) The concept for a muon-production system for a muon collider (or neutrino Magnet shield WC beads + water Shield must dissipate 2.4 MW Superconducting magnets tungsten-carbide (WC

  1. What is Ozone? Ozone (O3) is a molecule made up of three atoms of oxygen (O), and is mostly found in the strato-

    E-Print Network [OSTI]

    What is Ozone? Ozone (O3) is a molecule made up of three atoms of oxygen (O), and is mostly found it represents only a tiny fraction of the atmosphere, ozone is crucial for life on Earth. Ozone--acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. With- out ozone, the Sun

  2. Improved graphite furnace atomizer

    DOE Patents [OSTI]

    Siemer, D.D.

    1983-05-18T23:59:59.000Z

    A graphite furnace atomizer for use in graphite furnace atomic absorption spectroscopy is described wherein the heating elements are affixed near the optical path and away from the point of sample deposition, so that when the sample is volatilized the spectroscopic temperature at the optical path is at least that of the volatilization temperature, whereby analyteconcomitant complex formation is advantageously reduced. The atomizer may be elongated along its axis to increase the distance between the optical path and the sample deposition point. Also, the atomizer may be elongated along the axis of the optical path, whereby its analytical sensitivity is greatly increased.

  3. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 | Tags: Hopper, Materials Science Contact: Linda...

  4. Dose measurements behind reduced shielding at the Texas A&M University variable energy cyclotron

    E-Print Network [OSTI]

    Kay, Douglas Carey

    1982-01-01T23:59:59.000Z

    the reduced shielding by measuring neutron and gamma ray dose rates. A listing of currently available beams that are included in the study is given in Table 1. The purpose of this study is to provide information that can be used to limit radiation... conducted into accelerator shielding. It is known that a shield which is adequate to attenuate the high energy neutron component of the incident radiation will be more than enough to contain the charged particle and gamma ray com- ponents (NCRP77...

  5. Magnetic shielding of an electron beamline in a hadron accelerator enclosure

    SciTech Connect (OSTI)

    Kroc, T.K.; Schmidt, C.W.; Shemyakin, A.; /Fermilab

    2005-05-01T23:59:59.000Z

    The Fermilab Electron Cooling Project requires the operation of a 4.34 MeV electron beam in the same enclosure that houses the 120, 150 GeV Main Injector. Effective shielding of the magnetic fields from the ramped electrical busses and local static fields is necessary to maintain the high beam quality and recirculation efficiency required by the electron cooling system. This paper discusses the operational tolerances and the design of the beamline shielding, bus design, and bus shielding as well as experimental results from the prototype and final installation.

  6. Producing and Detecting Correlated atoms

    E-Print Network [OSTI]

    Christoph I. Westbrook; Martijn Schellekens; Aurélien Perrin; Valentina Krachmalnicoff; Jose Carlos Viana Gomes; Jean-Baptiste Trebbia; Jérôme Estève; Hong Chang; Isabelle Bouchoule; Denis Boiron; Alain Aspect; Tom Jeltes; John McNamara; Wim Hogervorst; Wim Vassen

    2006-09-04T23:59:59.000Z

    We discuss experiments to produce and detect atom correlations in a degenerate or nearly degenerate gas of neutral atoms. First we treat the atomic analog of the celebrated Hanbury Brown Twiss experiment, in which atom correlations result simply from interference effects without any atom interactions.We have performed this experiment for both bosons and fermions. Next we show how atom interactions produce correlated atoms using the atomic analog of spontaneous four-wavemixing. Finally, we briefly mention experiments on a one dimensional gas on an atom chip in which correlation effects due to both interference and interactions have been observed.

  7. General Corrosion and Localized Corrosion of the Drip Shield

    SciTech Connect (OSTI)

    F. Hua; K. Mon

    2003-06-24T23:59:59.000Z

    The recommended waste package (WP) design is described in BSC (2001a). The design includes a double-wall WP underneath a protective drip shield (DS) (BSC 2003a). The purpose of the process-level models developed in this report is to model dry oxidation (DOX), general corrosion (GC) and localized corrosion (LC) of the DS plate material, which is made of Ti Grade 7. The DS design also includes structural supports fabricated from Ti Grade 24. Degradation of Ti Grade 24 is not considered in this report. The DS provides protection for the waste package outer barrier (WPOB) both as a barrier to seepage water contact and a physical barrier to potential rockfall. This Model Report (MR) serves as a feed to the Integrated Waste Package Degradation Model (IWPD) analyses, and was developed in accordance with the Technical Work Plan (TWP) (BSC 2002a). The models contained in this report serve as a basis to determine whether or not the performance requirements for the DS can be met.

  8. Regulation of biological tissue mineralization through post-nucleation shielding

    E-Print Network [OSTI]

    Joshua C. Chang; Robert M. Miura

    2015-01-29T23:59:59.000Z

    In vertebrates, insufficient availability of calcium and phosphate ions in extracellular fluids leads to loss of bone density and neuronal hyper-excitability. To counteract this problem, calcium ions are present at high concentrations throughout body fluids -- at concentrations exceeding the saturation point. This condition leads to the opposite situation where unwanted mineral sedimentation may occur. Remarkably, ectopic or out-of-place sedimentation into soft tissues is rare, in spite of the thermodynamic driving factors. This fortunate fact is due to the presence of auto-regulatory proteins that are found in abundance in bodily fluids. Yet, many important inflammatory disorders such as atherosclerosis and osteoarthritis are associated with this undesired calcification. Hence, it is important to gain an understanding of the regulatory process and the conditions under which it can go awry. In this Letter, we use ideas from mean-field classical nucleation theory to study the regulation of sedimentation of calcium phosphate salts in biological tissues through the mechanism of post-nuclear shielding of nascent mineral particles by binding proteins. A critical concentration of regulatory protein is identified as a function of the physical parameters that describe the system.

  9. 2012 BlueCross BlueShield of Tennessee. BlueCross BlueShield of Tennessee, Inc., an Independent Licensee of the BlueCross BlueShield Association.

    E-Print Network [OSTI]

    Hong, Don

    Licensee of the BlueCross BlueShield Association. Pricing and Health Care Reform Overview Heather Westman Director, Actuarial #12;2 Agenda Pricing Overview Health Care Reform Overview Major Provisions Insurance Market Reforms Exchange Medical Loss Ratio Requirements Rate Review Reform Impact Scenarios

  10. Graphit-ceramic RF Faraday-thermal shield and plasma limiter

    DOE Patents [OSTI]

    Hwang, David L. (Princeton Junction, NJ); Hosea, Joel C. (Princeton, NJ)

    1989-01-01T23:59:59.000Z

    The present invention is directed to a process of brazing a ceramic mater to graphite. In particular, the brazing procedure is directed to the production of a novel brazed ceramic graphite product useful as a Faraday shield.

  11. RSMASS: A preliminary reactor/shield mass model for SDI applications

    SciTech Connect (OSTI)

    Marshall, A.C.

    1986-08-01T23:59:59.000Z

    A simple mathematical model (RSMASS) has been developed to provide rapid estimates of reactor and shield masses for space-based reactor power systems. Approximations are used rather than correlations or detailed calculations to estimate the reactor fuel mass and the masses of the moderator, structure, reflector, pressure vessel, miscellaneous components, and the reactor shield. The fuel mass is determined either by neutronics limits, specific power limits, or fuel burnup limits - whichever yields the largest mass. RSMASS requires the reactor power and energy, 24 reactor parameters, and 20 shield parameters to be specified. This parametric approach should provide good mass estimates for a very broad range of reactor types. Reactor and shield masses calculated by RSMASS were found to be in good agreement with the masses obtained from detailed calculations.

  12. Recent Economic Trends in Colorado's Oil and Gas Industry Martin Shields, Ph.D.

    E-Print Network [OSTI]

    's Oil and Gas Industry Martin Shields, Ph.D. Regional Economics Institute Trends in Colorado's Oil and Gas Industry Summary Colorado's economy lost issues affecting its prospects in Colorado. Although the oil and gas industry

  13. Radiation protection aspects of the EURISOL Multi-MW target shielding

    E-Print Network [OSTI]

    D. Ene, J.-C. David, D. Doré, B. Rapp, D. Ridikas

    This work is focused on the approach used to assess the radiological characterisation and to support waste analysis for the multi-MW power target shielding being the most challenging both in terms of technological and safety issues.

  14. PRINCIPLES OF RADIATION SHIELDING by Arthur B. Chilton, J. Kenneth Shultis and Richard E. Faw

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    8 Feb 95 ERRATA PRINCIPLES OF RADIATION SHIELDING by Arthur B. Chilton, J. Kenneth Shultis of a fast reactor or for a thick slab of low-moderating, hig-absorbing material. p. 275, line 15 the terms

  15. PRINCIPLES OF RADIATION SHIELDING by Arthur B. Chilton, J. Kenneth Shultis and Richard E. Faw

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    8 Feb 95 ERRATA PRINCIPLES OF RADIATION SHIELDING by Arthur B. Chilton, J. Kenneth Shultis of a fast reactor or for a thick slab of low­moderating, hig­absorbing material. p. 275, line 15 the terms

  16. Safety analysis report for packaging: the ORNL lithium hydroxide fire and impact shield

    SciTech Connect (OSTI)

    Evans, J.H.; Eversole, R.E.; Just, R.A.; Schaich, R.W.

    1984-07-01T23:59:59.000Z

    The ORNL Lithium Hydroxide Fire and Impact Shield and its packaging were designed and fabricated at Oak Ridge National Laboratory to permit the transport of Type B quantities of radioactive material and limited quantities of fissionable material. The shield and its packaging were evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported, and that evaluation is the subject of this report. Computational and test procedures were used to determine the structural integrity and thermal behavior of the shield relative to the general standards for normal conditions of transport and the standards for the hypothetical accident conditions. The results of the evaluation demonstrate that the shield and its packaging are in compliance with the applicable regulations. 16 references, 8 figures, 5 tables.

  17. Shielding analysis for a heavy ion beam chamber with plasma channels for ion transport

    SciTech Connect (OSTI)

    Sawan, M.E.; Peterson, R.R.; Yu, S.

    2000-06-28T23:59:59.000Z

    Neutronics analysis has been performed to assess the shielding requirements for the insulators and final focusing magnets in a modified HYLIFE-II target chamber that utilizes pre-formed plasma channels for heavy ion beam transport. Using 65 cm thick Flibe jet assemblies provides adequate shielding for the electrical insulator units. Additional shielding is needed in front of the final focusing superconducting quadrupole magnets. A shield with a thickness varying between 45 and 90 cm needs to be provided in front of the quadrupole unit. The final laser mirrors located along the channel axis are in the direct line-of-sight of source neutrons. Neutronics calculations were performed to determine the constraints on the placement of these mirrors to be lifetime components.

  18. Assessment of Dancoff adjusted Wigner-Seitz cells for self-shielding LWR lattices

    E-Print Network [OSTI]

    Roomy, Thomas Hayward

    2012-01-01T23:59:59.000Z

    The objective of this thesis was to assess the effectiveness of using a Wigner-Seitz (WS) cell with an adjusted moderator thickness to produce more accurate resonance self-shielded cross sections for light water reactor ...

  19. D0 Solenoid Upgrade Project: Chimney LN2 Radiation Shield Attachment Area Calculation

    SciTech Connect (OSTI)

    Rucinski, R.; /Fermilab

    1993-05-26T23:59:59.000Z

    A short calculation was done to check the attachment method of the radiation shield to it's LN2 cooling tubes. The case considered was only for the obround chimney section. The proposed attachment method was to use 1/8-inch plug welds spaced every 5-inch along the length of the shield. The calculations were done conservatively for 6-inch spacing between plug welds. The criteria used was that the LN2 shield warmest temperature be less than 2 K above the temperature of the LN2 fluid. Using a very conservative heat transfer model. the calculations predict that the warmest temperature on the radiation shield will be < 1.4 K warmer than the LN2 fluid temperature.

  20. Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Orrell, John L.; Ankney, Austin S.; Berguson, Timothy J.

    2011-09-21T23:59:59.000Z

    This document provides a detailed study of cost and materials that could be used to shield the detector material of the international Tonne-scale germanium neutrinoless double-beta decay experiment from hadronic particles from cosmic ray showers at the Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during storage; in particular, when the detector material is being worked on at the detector manufacturer's facility. This work considers two options for shielding the detector material from cosmic ray particles. One option is to use a pre-existing structure already located near the detector manufacturer, such as Canberra Industries in Meriden, Connecticut. The other option is to build a shield onsite at a detector manufacturer's site. This paper presents a cost and efficiency analysis of such construction.

  1. Pollution prevention benefits of non-hazardous shielding glovebox gloves - 11000

    SciTech Connect (OSTI)

    Cournoyer, Michael E [Los Alamos National Laboratory; Dodge, Robert L [Los Alamos National Laboratory

    2011-01-11T23:59:59.000Z

    Radiation shielding is commonly used to protect the glovebox worker from unintentional direct and secondary radiation exposure, while working with plutonium-238 and plutonium-239. Shielding glovebox gloves are traditionally composed of lead-based materials, i.e., hazardous waste. This has prompted the development of new, non-hazardous shielding glovebox gloves. No studies, however, have investigated the pollution prevention benefits of these new glovebox gloves. We examined both leaded and non-hazardous shielding glovebox gloves. The nonhazardous substitutes are higher in cost, but this is offset by eliminating the costs associated with onsite waste handling of Resource Conservation and Recovery Act (RCRA) items. In the end, replacing lead with non-hazardous substitutes eliminates waste generation and future liability.

  2. EMI shield enhancement through the addition of copper coated glass fibers

    E-Print Network [OSTI]

    Montanye, Jeffrey Richard

    1988-01-01T23:59:59.000Z

    EMI SHIELD ENHANCEMENT THROUGH THE ADDITION OF COPPER COATED GLASS FIBERS A Thesis by JEFFREY RICHARD MONTANYE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August f988 Major Subject: Interdisciplinary Engineering EMI SHIELD ENHANCEMENT THROUGH THE ADDITION OF COPPER COATED GLASS FIBERS A Thesis by JEFFREY RICHARD MONTANYE Approved as to style and content by: George W. Halldin (Chair...

  3. Progress on Establishing Guidelines for National Ignition Facility (NIF) Experiments to Extend Debris Shield Lifetime

    SciTech Connect (OSTI)

    Tobin, M; Eder, D; Braun, D; MacGowan, B

    2000-07-26T23:59:59.000Z

    The survivability and performance of the debris shields on the National Ignition Facility (NIF) are a key factor for the successful conduct and affordable operation of the facility. The improvements required over Nova debris shields are described. Estimates of debris shield lifetimes in the presence of target emissions with 4 - 5 J/cm{sup 2} laser fluences (and higher) indicate lifetimes that may contribute unacceptably to operations costs for NIF. We are developing detailed guidance for target and experiment designers for NIF to assist in minimizing the damage to, and therefore the cost of, maintaining NIF debris shields. The guidance limits the target mass that is allowed to become particulate on the debris shields (300 mg). It also limits the amount of material that can become shrapnel for any given shot (10 mg). Finally, it restricts the introduction of non-volatile residue (NVR) that is a threat to the sol-gel coatings on the debris shields to ensure that the chamber loading at any time is less than 1 pg/cm{sup 2}. We review the experimentation on the Nova chamber that included measuring quantities of particulate on debris shields by element and capturing shrapnel pieces in aerogel samples mounted in the chamber. We also describe computations of x-ray emissions from a likely NIF target and the associated ablation expected from this x-ray exposure on supporting target hardware. We describe progress in assessing the benefits of a pre-shield and the possible impact on the guidance for target experiments on NIF. Plans for possible experimentation on Omega and other facilities to improve our understanding of target emissions and their impacts are discussed. Our discussion of planned future work provides a forum to invite possible collaboration with the IFE community.

  4. EMI shield enhancement through the addition of copper coated glass fibers 

    E-Print Network [OSTI]

    Montanye, Jeffrey Richard

    1988-01-01T23:59:59.000Z

    EMI SHIELD ENHANCEMENT THROUGH THE ADDITION OF COPPER COATED GLASS FIBERS A Thesis by JEFFREY RICHARD MONTANYE Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August f988 Major Subject: Interdisciplinary Engineering EMI SHIELD ENHANCEMENT THROUGH THE ADDITION OF COPPER COATED GLASS FIBERS A Thesis by JEFFREY RICHARD MONTANYE Approved as to style and content by: George W. Halldin (Chair...

  5. Molecular based magnets comprising vanadium tetracyanoethylene complexes for shielding electromagnetic fields

    DOE Patents [OSTI]

    Epstein, Arthur J. (Columbus, OH); Morin, Brian G. (Columbus, OH)

    1998-01-01T23:59:59.000Z

    The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors.

  6. Boron cage compound materials and composites for shielding and absorbing neutrons

    DOE Patents [OSTI]

    Bowen, III, Daniel E; Eastwood, Eric A

    2014-03-04T23:59:59.000Z

    Boron cage compound-containing materials for shielding and absorbing neutrons. The materials include BCC-containing composites and compounds. BCC-containing compounds comprise a host polymer and a BCC attached thereto. BCC-containing composites comprise a mixture of a polymer matrix and a BCC filler. The BCC-containing materials can be used to form numerous articles of manufacture for shielding and absorbing neutrons.

  7. Molecular based magnets comprising vanadium tetracyanoethylene complexes for shielding electromagnetic fields

    DOE Patents [OSTI]

    Epstein, A.J.; Morin, B.G.

    1998-10-13T23:59:59.000Z

    The invention presents a vanadium tetracyanoethylene solvent complex for electromagnetic field shielding, and a method for blocking low frequency and magnetic fields using these vanadium tetracyanoethylene compositions. The compositions of the invention can be produced at ambient temperature and are light weight, low density and flexible. The materials of the present invention are useful as magnetic shields to block low frequency fields and static fields, and for use in cores in transformers and motors. 21 figs.

  8. Double active shielded magnetic field gradient design with minimum inductance method

    E-Print Network [OSTI]

    Wang, Xu

    1992-01-01T23:59:59.000Z

    DOUBLE ACTIVE SHIELDED MAGNETIC FIELD GRADIENT DESIGN WITH MINIMUM INDUCTANCE METHOD A Thesis by XU WANG Submitted to the Oflice of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Physics DOUBLE ACTIVE SHIELDED MAGNETIC FIELD GRADIENT DESIGN WITH MINIMUM INDUCTANCE METHOD A Thesis by XU WANG Approved as to style and content by: F. R. Huson (Chair of Committee) Steve Wry (Member) Edward...

  9. Packaging and Disposal of a Radium-beryllium Source using Depleted Uranium Polyethylene Composite Shielding

    SciTech Connect (OSTI)

    Keith Rule; Paul Kalb; Pete Kwaschyn

    2003-02-11T23:59:59.000Z

    Two, 111-GBq (3 Curie) radium-beryllium (RaBe) sources were in underground storage at the Brookhaven National Laboratory (BNL) since 1988. These sources originated from the Princeton Plasma Physics Laboratory (PPPL) where they were used to calibrate neutron detection diagnostics. In 1999, PPPL and BNL began a collaborative effort to expand the use of an innovative pilot-scale technology and bring it to full-scale deployment to shield these sources for eventual transport and burial at the Hanford Burial site. The transport/disposal container was constructed of depleted uranium oxide encapsulated in polyethylene to provide suitable shielding for both gamma and neutron radiation. This new material can be produced from recycled waste products (depleted uranium and polyethylene), is inexpensive, and can be disposed with the waste, unlike conventional lead containers, thus reducing exposure time for workers. This paper will provide calculations and information that led to the initial design of the shielding. We will also describe the production-scale processing of the container, cost, schedule, logistics, and many unforeseen challenges that eventually resulted in the successful fabrication and deployment of this shield. We will conclude with a description of the final configuration of the shielding container and shipping package along with recommendations for future shielding designs.

  10. PACKAGING AND DISPOSAL OF A RADIUM BERYLLIUM SOURCE USING DEPLETED URANIUM POLYETHYLENE COMPOSITE SHIELDING.

    SciTech Connect (OSTI)

    RULE,K.; KALB,P.; KWASCHYN,P.

    2003-02-23T23:59:59.000Z

    Two, 111 GBq (3 Curie) radium-beryllium (RaBe) sources were in underground storage at the Brookhaven National Laboratory (BNL) since 1988. These sources originated from Princeton Plasma Physics Laboratory (PPPL) where they were used to calibrate neutron detection diagnostics. In 1999, PPPL and BNL began a collaborative effort to expand the use of an innovative pilot-scale technology and bring it to full-scale deployment to shield these sources for eventual transport and burial at the Hanford Burial site. The transport/disposal container was constructed of depleted uranium oxide encapsulated in polyethylene to provide suitable shielding for both gamma and neutron radiation. This new material can be produced from recycled waste products (DU and polyethylene), is inexpensive, and can be disposed with the waste, unlike conventional lead containers, thus reducing exposure time for workers. This paper will provide calculations and information that led to the initial design of the shielding. We will also describe the production-scale processing of the container, cost, schedule, logistics, and many unforeseen challenges that eventually resulted in the successful fabrication and deployment of this shield. We will conclude with a description of the final configuration of the shielding container and shipping package along with recommendations for future shielding designs.

  11. Nuclear reactor having a polyhedral primary shield and removable vessel insulation

    DOE Patents [OSTI]

    Ekeroth, D.E.; Orr, R.

    1993-12-07T23:59:59.000Z

    A nuclear reactor is provided having a generally cylindrical reactor vessel disposed within an opening in a primary shield. The opening in the primary shield is defined by a plurality of generally planar side walls forming a generally polyhedral-shaped opening. The reactor vessel is supported within the opening in the primary shield by reactor vessel supports which are in communication and aligned with central portions of some of the side walls. The reactor vessel is connected to the central portions of the reactor vessel supports. A thermal insulation polyhedron formed from a plurality of slidably insertable and removable generally planar insulation panels substantially surrounds at least a portion of the reactor vessel and is disposed between the reactor vessel and the side walls of the primary shield. The shape of the insulation polyhedron generally corresponds to the shape of the opening in the primary shield. Reactor monitoring instrumentation may be mounted in the corners of the opening in the primary shield between the side walls and the reactor vessel such that insulation is not disposed between the instrumentation and the reactor vessel. 5 figures.

  12. Nuclear reactor having a polyhedral primary shield and removable vessel insulation

    DOE Patents [OSTI]

    Ekeroth, Douglas E. (Delmont, PA); Orr, Richard (Pittsburgh, PA)

    1993-01-01T23:59:59.000Z

    A nuclear reactor is provided having a generally cylindrical reactor vessel disposed within an opening in a primary shield. The opening in the primary shield is defined by a plurality of generally planar side walls forming a generally polyhedral-shaped opening. The reactor vessel is supported within the opening in the primary shield by reactor vessel supports which are in communication and aligned with central portions of some of the side walls. The reactor vessel is connected to the central portions of the reactor vessel supports. A thermal insulation polyhedron formed from a plurality of slidably insertable and removable generally planar insulation panels substantially surrounds at least a portion of the reactor vessel and is disposed between the reactor vessel and the side walls of the primary shield. The shape of the insulation polyhedron generally corresponds to the shape of the opening in the primary shield. Reactor monitoring instrumentation may be mounted in the corners of the opening in the primary shield between the side walls and the reactor vessel such that insulation is not disposed between the instrumentation and the reactor vessel.

  13. Atomic and molecular supernovae

    SciTech Connect (OSTI)

    Liu, W.

    1997-12-01T23:59:59.000Z

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  14. Summary of Blast Shield and Material Testing for Development of Solid Debris Collection at the National Ignition Facility (NIF)

    SciTech Connect (OSTI)

    Shaughnessy, D A; Gostic, J M; Moody, K J; Grant, P M; Lewis, L A; Hutcheon, I D

    2011-11-21T23:59:59.000Z

    The ability to collect solid debris from the target chamber following a NIF shot has application for both capsule diagnostics, particularly for fuel-ablator mix, and measuring cross sections relevant to the Stockpile Stewardship program and nuclear astrophysics. Simulations have shown that doping the capsule with up to 10{sup 15} atoms of an impurity not otherwise found in the capsule does not affect its performance. The dopant is an element that will undergo nuclear activations during the NIF implosion, forming radioactive species that can be collected and measured after extraction from the target chamber. For diagnostics, deuteron or alpha induced reactions can be used to probe the fuel-ablator mix. For measuring neutron cross sections, the dopant should be something that is sensitive to the 14 MeV neutrons produced through the fusion of deuterium and tritium. Developing the collector is a challenge due to the extreme environment of the NIF chamber. The collector surface is exposed to a large photon flux from x-rays and unconverted laser light before it is exposed to a debris wind that is formed from vaporized material from the target chamber center. The photons will ablate the collector surface to some extent, possibly impeding the debris from reaching the collector and sticking. In addition, the collector itself must be mechanically strong enough to withstand the large amount of energy it will be exposed to, and it should be something that will be easy to count and chemically process. In order to select the best material for the collector, a variety of different metals have been tested in the NIF chamber. They were exposed to high-energy laser shots in order to evaluate their postshot surface characterization, morphology, degree of melt, and their ability to retain debris from the chamber center. The first set of samples consisted of 1 mm thick pieces of aluminum that had been fielded in the chamber as blast shields protecting the neutron activation diagnostic. Ten of these pieces were fielded at the equator and one was fielded on the pole. The shields were analyzed using a combination of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), x-ray fluorescence (XRF), neutron activation analysis (NAA) and chemical leaching followed by mass spectrometry. On each shield, gold debris originating from the gold hohlraum was observed, as well as large quantities of debris that were present in the center of the target chamber at the time of the shot (i.e., stainless steel, indium, copper, etc.) Debris was visible in the SEM as large blobs or splats of material that had encountered the surface of the aluminum and stuck. The aluminum itself had obviously melted and condensed, and some of the large debris splats arrived after the surface had already hardened. Melt depth was determined by cross sectioning the pieces and measuring the melted surface layers via SEM. After the SEM analysis was completed, the pieces were sent for NAA at the USGS reactor and were analyzed by U. Greife at the Colorado School of Mines. The NAA showed that the majority of gold mass present on the shields was not in the form of large blobs and splats, but was present as small particulates that had most likely formed as condensed vapor. Further analysis showed that the gold was entrained in the melted aluminum surface layers and did not extend down into the bulk of the aluminum. Once the gold mass was accounted for from the NAA, it was determined that the aluminum fielded at the equator was collecting a fraction of the total gold hohlraum mass equivalent to 120% {+-} 10% of the solid angle subtended by the shield. The attached presentation has more information on the results of the aluminum blast shield analysis. In addition to the information given in the presentation, the surfaces of the shields have been chemically leached and submitted for mass spectrometric analysis. The results from that analysis are expected to arrive after the due date of this report and will be written up at a later time. Based on the results of the aluminum b

  15. Metal atomization spray nozzle

    DOE Patents [OSTI]

    Huxford, T.J.

    1993-11-16T23:59:59.000Z

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  16. Atomizing nozzle and method

    DOE Patents [OSTI]

    Ting, Jason (Ames, IA); Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

    2000-03-16T23:59:59.000Z

    A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

  17. Optical atomic magnetometer

    DOE Patents [OSTI]

    Budker, Dmitry; Higbie, James; Corsini, Eric P

    2013-11-19T23:59:59.000Z

    An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

  18. Atomic mass compilation 2012

    SciTech Connect (OSTI)

    Pfeiffer, B., E-mail: bpfeiffe@uni-mainz.de [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Venkataramaniah, K. [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India)] [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India); Czok, U. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)] [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); Scheidenberger, C. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)

    2014-03-15T23:59:59.000Z

    Atomic mass reflects the total binding energy of all nucleons in an atomic nucleus. Compilations and evaluations of atomic masses and derived quantities, such as neutron or proton separation energies, are indispensable tools for research and applications. In the last decade, the field has evolved rapidly after the advent of new production and measuring techniques for stable and unstable nuclei resulting in substantial ameliorations concerning the body of data and their precision. Here, we present a compilation of atomic masses comprising the data from the evaluation of 2003 as well as the results of new measurements performed. The relevant literature in refereed journals and reports as far as available, was scanned for the period beginning 2003 up to and including April 2012. Overall, 5750 new data points have been collected. Recommended values for the relative atomic masses have been derived and a comparison with the 2003 Atomic Mass Evaluation has been performed. This work has been carried out in collaboration with and as a contribution to the European Nuclear Structure and Decay Data Network of Evaluations.

  19. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    A. Deltuva

    2012-03-28T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  20. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    Deltuva, A

    2012-01-01T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  1. Safety analysis report for the National Low-Temperature Neutron Irradiation Facility (NLTNIF) at the ORNL Bulk Shielding Reactor (BSR)

    SciTech Connect (OSTI)

    Coltman, R.R. Jr.; Kerchner, H.R.; Klabunde, C.E.; Richardson, S.A.

    1986-06-01T23:59:59.000Z

    This report provides information concerning: the experiment facility; experiment assembly; instrumentation and controls; materials; radioactivity; shielding; thermodynamics; estimated or measured reactivity effects; procedures; hazards; and quality assurance. (JDB)

  2. Experimental results of neutron fluence outside an iron shield in the forward direction

    SciTech Connect (OSTI)

    Torres, M.M.C. [Argonne National Lab., IL (United States); Elwyn, A.J. [Fermi National Accelerator Lab., Batavia, IL (United States); Fein, D.; James, E.; Johns, K. [Arizona Univ., Tucson, AZ (United States); Davis, W. [Ball State Univ., Muncie, IN (United States); Ciampa, D.P. [Minnesota Univ., Minneapolis, MN (United States); Mierkiewicz, E. [Northern Illinois Univ., De Kalb, IL (United States)

    1996-09-01T23:59:59.000Z

    Analyses of both lateral shielding measurements and Monte Carlo calculations for beam stop geometry for incident hadrons at energies between 10 GeV and 10 TeV suggests that the dose equivalent can be represented by the expression H = H{sub 0}(E)e{sup -r/{lambda}}/r{sup 2} where H, is the source term, r is the radial distance to the point of interest in the shield, and {lambda} is the effective interaction length, or absorption mean free path. However, unlike the lateral shielding case, there is no similarly simple analytical expression that can be used to describe the on-axis longitudinal cascade development. In this study the results from the measurement in the forward direction of neutron fluence spectra (and the derived quantity dose equivalent) for 25 to 150 GeV pions incident on an iron beam stop as a function of thickness of iron are presented. The observed dependence of both fluence and dose equivalent on shield thickness and hadron energy was then quantified in terms of an expression in which a build up factor as well as an attenuation term was included. On the basis of this analysis the conversion factor from fluence to dose equivalent was also determined for these forward going neutrons. This work represents the first systematic study at an high energy accelerator of the depth dependence of neutron fluence in longitudinal shielding.

  3. Plume dynamics and shielding characteristics of nanosecond scale multiple pulse in carbon ablation

    SciTech Connect (OSTI)

    Pathak, Kedar; Povitsky, Alex [Department of Mechanical Engineering, University of Akron, Akron, Ohio 44325-3903 (United States)

    2008-12-01T23:59:59.000Z

    The behavior of ablated plumes produced by nanosecond scale multiple laser pulses typical for carbon ablation is studied in order to understand the plume expansion dynamics and shielding effect of plume with special interest to ionization of plumes. The patterns of a planar plume (typical for channel cutting) and an axisymmetric plume (typical for hole drilling) appear to be quite different. Ionization in carbon plume is estimated using the Saha equation. An iterative procedure is developed to determine the local equilibrium temperature affected by ionization. It is shown that though shielding due to the presence of ionized particles in carbon plume is small, the effect of ionization on plume temperature can be considerable. Shielding effect is calculated for laser pulses with different time intervals between pulses. The effects of high temperature and low density of plume are conflicting and cause shielding behavior to be nonmonotonic. It is shown that the nonmonotonic dependence of the delivered laser energy, the pulse number, and the difference in shielding characteristics between planar and axisymmetric formulations increase with the time duration between two consecutive pulses.

  4. Influence of nitrogen in the shielding gas on corrosion resistance of duplex stainless steel welds

    SciTech Connect (OSTI)

    Bhatt, R.B.; Kamat, H.S.; Ghosal, S.K.; De, P.K.

    1999-10-01T23:59:59.000Z

    The influence of nitrogen in shielding gas on the corrosion resistance of welds of a duplex stainless steel (grade U-50), obtained by gas tungsten arc (GTA) with filler wire, autogenous GTA (bead-on-plate), electron beam welding (EBW), and microplasma techniques, has been evaluated in chloride solutions at 30 C. Pitting attack has been observed in GTA, electron beam welding, and microplasma welds when welding has been carried out using pure argon as the shielding gas. Gas tungsten arc welding with 5 to 10% nitrogen and 90 to 95% argon, as the shielding gas, has been found to result in an improved pitting corrosion resistance of the weldments of this steel. However, the resistance of pitting of autogenous welds (bead-on-plate) obtained in pure argon as the shielding gas has been observed to remain unaffected. Microscopic examination, electron probe microanalysis (EPMA), and x-ray diffraction studies have revealed that the presence of nitrogen in the shielding gas in the GTA welds not only modifies the microstructure and the austenite to ferrite ratio but also results in a nearly uniform distribution of the various alloying elements, for example, chromium, nickel, and molybdenum among the constituent phases, which are responsible for improved resistance to pitting corrosion.

  5. Design of a dual species atom interferometer for space

    E-Print Network [OSTI]

    Thilo Schuldt; Christian Schubert; Markus Krutzik; Lluis Gesa Bote; Naceur Gaaloul; Jonas Hartwig; Holger Ahlers; Waldemar Herr; Katerine Posso-Trujillo; Jan Rudolph; Stephan Seidel; Thijs Wendrich; Wolfgang Ertmer; Sven Herrmann; André Kubelka-Lange; Alexander Milke; Benny Rievers; Emanuele Rocco; Andrew Hinton; Kai Bongs; Markus Oswald; Matthias Franz; Matthias Hauth; Achim Peters; Ahmad Bawamia; Andreas Wicht; Baptiste Battelier; Andrea Bertoldi; Philippe Bouyer; Arnaud Landragin; Didier Massonnet; Thomas Lévèque; Andre Wenzlawski; Ortwin Hellmig; Patrick Windpassinger; Klaus Sengstock; Wolf von Klitzing; Chris Chaloner; David Summers; Philip Ireland; Ignacio Mateos; Carlos F. Sopuerta; Fiodor Sorrentino; Guglielmo M. Tino; Michael Williams; Christian Trenkel; Domenico Gerardi; Michael Chwalla; Johannes Burkhardt; Ulrich Johann; Astrid Heske; Eric Wille; Martin Gehler; Luigi Cacciapuoti; Norman Gürlebeck; Claus Braxmaier; Ernst Rasel

    2014-12-08T23:59:59.000Z

    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species $^{85}$Rb/$^{87}$Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for $10^{-11}$ mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (819 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.

  6. Atomic Force Microscope

    SciTech Connect (OSTI)

    Day, R.D.; Russell, P.E.

    1988-12-01T23:59:59.000Z

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  7. Iowa Powder Atomization Technologies

    ScienceCinema (OSTI)

    None

    2013-03-01T23:59:59.000Z

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  8. Iowa Powder Atomization Technologies

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    The same atomization effect seen in a fuel injector is being applied to titanium metal resulting in fine titanium powders that are less than half the width of a human hair. Titanium melts above 3,000°F and is highly corrosive therefore requiring specialized containers. The liquid titanium is poured through an Ames Laboratory - USDOE patented tube which is intended to increase the energy efficiency of the atomization process, which has the ability to dramatically decrease the cost of fine titanium powders. This novel process could open markets for green manufacturing of titanium components from jet engines to biomedical implants.

  9. Orthogonally interdigitated shielded serpentine travelling wave cathod ray tube deflection structure

    SciTech Connect (OSTI)

    Hagen, E.C.; Hudson, C.L.

    1993-10-27T23:59:59.000Z

    This invention comprises a new deflection structure which deflects a beam of charged particles, such as an electron beam, includes a serpentine set for transmitting a deflection field, and shielding frame for housing the serpentine set. The serpentine set includes a vertical serpentine deflection element and a horizontal serpentine deflection element. These deflection elements are identical and are interdigitatedly and orthogonally disposed relative to each other, for forming a central transmission passage, through which the electron beam passes and is deflected by the deflection field to minimize drift space signal distortion. The shielding frame includes a plurality of ground blocks and forms an internal serpentine trough within these ground blocks for housing the serpentine set. The deflection structure further includes a plurality of feedthrough connectors which are inserted through the shielding frame and which are electrically connected to the serpentine set.

  10. Optimizing moderation of He-3 neutron detectors for shielded fission sources

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rees, Lawrence B.; Czirr, J. Bart

    2012-11-01T23:59:59.000Z

    Abstract: The response of 3-He neutron detectors is highly dependent on the amount of moderator incorporated into the detector system. If there is too little moderation, neutrons will not react with the 3-He. If there is too much moderation, neutrons will not reach the 3-He. In applications for portal or border monitors where 3He detectors are used to interdict illicit Importation of plutonium, the fission source is always shielded to some extent. Since the energy distribution of neutrons emitted from the source depends on the amount and type of shielding present, the optimum placement of moderating material around 3-He tubesmore »is a function of shielding. In this paper, we use Monte Carlo techniques to model the response of 3-He tubes placed in polyethylene boxes for moderation. To model the shielded fission neutron source, we use a 252-Cf source placed in the center of spheres of water of varying radius. Detector efficiency as a function of box geometry and shielding are explored. We find that increasing the amount of moderator behind and to the sides of the detector generally improves the detector response, but that benefits are limited if the thickness of the polyethylene moderator is greater than about 5-7 cm. The thickness of the moderator in front of the 3He tubes, however, is very important. For bare sources, about 5-6 cm of moderator is optimum, but as the shielding increases, the optimum thickness of this moderator decreases to 0-1 cm. A two-tube box with a moderator thickness of 5 cm in front of the first tube and a thickness of 1 cm in front of the second tube is proposed to improve the detector's sensitivity to lower-energy neutrons.« less

  11. Optimizing moderation of He-3 neutron detectors for shielded fission sources

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rees, Lawrence B. [Brigham Young University, Provo, UT (United States); Czirr, J. Bart [Brigham Young University, Provo, UT (United States)

    2012-11-01T23:59:59.000Z

    Abstract: The response of 3-He neutron detectors is highly dependent on the amount of moderator incorporated into the detector system. If there is too little moderation, neutrons will not react with the 3-He. If there is too much moderation, neutrons will not reach the 3-He. In applications for portal or border monitors where 3He detectors are used to interdict illicit Importation of plutonium, the fission source is always shielded to some extent. Since the energy distribution of neutrons emitted from the source depends on the amount and type of shielding present, the optimum placement of moderating material around 3-He tubes is a function of shielding. In this paper, we use Monte Carlo techniques to model the response of 3-He tubes placed in polyethylene boxes for moderation. To model the shielded fission neutron source, we use a 252-Cf source placed in the center of spheres of water of varying radius. Detector efficiency as a function of box geometry and shielding are explored. We find that increasing the amount of moderator behind and to the sides of the detector generally improves the detector response, but that benefits are limited if the thickness of the polyethylene moderator is greater than about 5-7 cm. The thickness of the moderator in front of the 3He tubes, however, is very important. For bare sources, about 5-6 cm of moderator is optimum, but as the shielding increases, the optimum thickness of this moderator decreases to 0-1 cm. A two-tube box with a moderator thickness of 5 cm in front of the first tube and a thickness of 1 cm in front of the second tube is proposed to improve the detector's sensitivity to lower-energy neutrons.

  12. Development of a New Shielding Model for JB-Line Dose Rate Calculations

    SciTech Connect (OSTI)

    Buckner, M.R.

    2001-08-09T23:59:59.000Z

    This report describes the shielding model development for the JB-Line Upgrade project. The product of this effort is a simple-to-use but accurate method of estimating the personnel dose expected for various operating conditions on the line. The current techniques for shielding calculations use transport codes such as ANISN which, while accurate for geometries which can be accurately approximated as one dimensional slabs, cylinders or spheres, fall short in calculating configurations in which two-or three-dimensional effects (e.g., streaming) play a role in the dose received by workers.

  13. Graphite-ceramic rf Faraday-thermal shield and plasma limiter

    DOE Patents [OSTI]

    Hwang, D.L.Q.; Hosea, J.C.

    1983-05-05T23:59:59.000Z

    The present invention is directed to a brazing procedure for joining a ceramic or glass material (e.g., Al/sub 2/O/sub 3/ or Macor) to graphite. In particular, the present invention is directed to a novel brazing procedure for the production of a brazed ceramic graphite product useful as a Faraday shield. The brazed ceramic graphite Faraday shield of the present invention may be used in Magnetic Fusion Devices (e.g., Princeton Large Torus Tokamak) or other high temperature resistant apparatus.

  14. Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J.; Fast, James E.

    2012-04-15T23:59:59.000Z

    This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.

  15. Apparatus for characterizing conductivity of materials by measuring the effect of induced shielding currents therein

    DOE Patents [OSTI]

    Doss, James D. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples.

  16. Apparatus for characterizing conductivity of materials by measuring the effect of induced shielding currents therein

    DOE Patents [OSTI]

    Doss, J.D.

    1991-05-14T23:59:59.000Z

    Apparatus and method for noncontact, radio-frequency shielding current characterization of materials is disclosed. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 10 figures.

  17. Evaluation of the effectiveness of shielding and filtering of HVDC converter stations

    SciTech Connect (OSTI)

    Dallaire, R.D.; Maruvada, P.S.

    1989-04-01T23:59:59.000Z

    The electromagnetic interference (EMI) generated by the periodic turn-on and turn-off of the valves is an important consideration in the design of HVDC converter stations. Remedial measures such as shielding the valve hall and filtering have been used in order to reduce the interference levels to acceptable values. The application of recently-developed Numerical Electromagnetic Code (NEC) to the problem of EMI from HVDC converter stations is investigated in this paper, with particular emphasis on evaluating the effectiveness of valve hall shielding and filtering.

  18. Modeling of capacitive and electromagnetic field shielding effects in a CVT.

    SciTech Connect (OSTI)

    Gover, James E. (Kettering University); Bou, Jimmy; Sommerville, William (Kettering University); Sanchez, Robert O.

    2005-08-01T23:59:59.000Z

    In the discharge of a capacitor the current was measured with a current viewing transformer (CVT). In addition to measuring the current flowing through the CVT primary, a 51 MHz noise signal was added to the primary current. When the CVT was covered with a gold shield, the noise was eliminated. Analysis of the measured results indicate that the gold layer reflected the electromagnetic that was generated by current flowing in the primary and that the capacitance between the shield and the CVT secondary had no measurable effect on the CVT output.

  19. Elements & Compounds Atoms (Elements)

    E-Print Network [OSTI]

    Frey, Terry

    #12;Elements & Compounds #12;Atoms (Elements) Molecules (Compounds) Cells Elements & Compounds #12 #12;First shell Second shell Third shell Hydrogen 1H Lithium 3Li Sodium 11Na Beryllium 4Be Magnesium energy Higher energy (a) A ball bouncing down a flight of stairs provides an analogy for energy levels

  20. Zi-Wei Lin Oct 5, 2004 UAH / NASA Space Radiation Shielding Program, MS Determine Important Nuclear Fragmentation Processes

    E-Print Network [OSTI]

    Lin, Zi-wei

    Zi-Wei Lin Oct 5, 2004 UAH / NASA Space Radiation Shielding Program, MS Determine Important Nuclear Fragmentation Processes for Space Radiation Protection in Human Space Explorations Why do we need to study? Conclusions Zi-Wei Lin University of Alabama in Huntsville/ NASA Space Radiation Shielding Program, MSFC #12

  1. Phanerozoic tectonothermal history of the ArabianNubian shield in the Eastern Desert of Egypt: evidence from fission track

    E-Print Network [OSTI]

    Fritz, Harald

    Phanerozoic tectonothermal history of the Arabian­Nubian shield in the Eastern Desert of Egypt were performed in the Eastern Desert of Egypt. The results provide insights into the processes driving reserved. Keywords: Phanerozoic; Fission track thermochronology; Palaeostress; Arabian­Nubien shield; Egypt

  2. Atom-by-atom nucleation and growth of graphene nanopores

    E-Print Network [OSTI]

    Golovchenko, Jene A.

    Atom-by-atom nucleation and growth of graphene nanopores Christopher J. Russoa,b and J. A February 17, 2012 (received for review December 9, 2011) Graphene is an ideal thin membrane substrate structures in graphene with atomic preci- sion. It consists of inducing defect nucleation centers with ener

  3. Atomic phenomena in dense plasmas

    SciTech Connect (OSTI)

    Weisheit, J.C.

    1981-03-01T23:59:59.000Z

    The following chapters are included: (1) the plasma environment, (2) perturbations of atomic structure, (3) perturbations of atomic collisions, (4) formation of spectral lines, and (5) dielectronic recombination. (MOW)

  4. atoms: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  5. A nonself sugar mimic of the HIV glycan shield shows enhanced antigenicity

    E-Print Network [OSTI]

    Davis, Ben G.

    of protein glycans recognized by 2G12, their antigenicity is significantly enhanced. Logical variation are either difficult to access or shielded from recognition by the immune system by an extensive display patients that provide protection against viral challenge in animal models (5­9) as well as the more recent

  6. The City of Vancouver's Approach to Electric Vehicles: Malcolm Shield, Climate Policy Manager

    E-Print Network [OSTI]

    California at Davis, University of

    V ­ BCH Conservation Collaborative Identifies EVs as priority area City buys first Canadian plug-in Prius, Community Energy Assoc., Van. Elec. Vehicle Assoc., & industry $730k Funding secured, with $70k City1 The City of Vancouver's Approach to Electric Vehicles: 7 Pillars Malcolm Shield, Climate Policy

  7. PART A: TYPE OF COVERAGE HMO Colorado/Anthem Blue Cross and Blue Shield

    E-Print Network [OSTI]

    PART A: TYPE OF COVERAGE HMO Colorado/Anthem Blue Cross and Blue Shield Colorado Higher Education Insurance Benefits Alliance Trust Effective January 1, 2015 Blue Advantage HMO/Point-of-Service(POS) Plan and copayment options reflect the amount the covered person will pay. BlueAdvantage HMO

  8. Effect of charge reduction on shielding in dusty plasmas K. Avinash, A. Bhattacharjee, and R. Merlino

    E-Print Network [OSTI]

    Merlino, Robert L.

    - ical models and molecular dynamic simulations pertaining to dusty plasmas. However, the notion produces an electric field in the plasma. A question, which then naturally arises, is how this electric there is a single grain in a large volume, the electrons and ions will shield the electric field within

  9. Summary of Surface Swipe Sampling for Beryllium on Lead Bricks and Shielding

    SciTech Connect (OSTI)

    Paik, S Y; Barron, D A

    2011-08-03T23:59:59.000Z

    Approximately 25,000 lbs of lead bricks at Site 300 were assessed by the Site 300 Industrial Hygienis tand Health Physicist for potential contamination of beryllium and radiation for reuse. These lead bricks and shielding had been used as shielding material during explosives tests that included beryllium and depleted uranium. Based on surface swipe sampling that was performed between July 26 and October 11, 2010, specifically for beryllium, the use of a spray encapsulant was found to be an effective means to limit removable surface contamination to levels below the DOE release limit for beryllium, which is 0.2 mcg/100 cm{sup 2}. All the surface swipe sampling data for beryllium and a timeline of when the samples were collected (and a brief description) are presented in this report. On December 15, 2010, the lead bricks and shielding were surveyed with an ion chamber and indicated dose rates less than 0.05 mrem per hour on contact. This represents a dose rate consistent with natural background. An additional suevey was performed on February 8, 2011, using a GM survey instrument to estimate total activity on the lead bricks and shielding, confirming safe levels of radioactivity. The vendor is licensed to possess and work with radioactive material.

  10. Radiation protection aspects of the EURISOL Multi-MW target shielding

    E-Print Network [OSTI]

    Ene, D; Doré, D; Rapp, B; Ridikas, D

    This paper which will be submitted to Annals in Nuclear Energy is focused on the approach used to assess the radiological characterisation and to support waste analysis for the multi-MW power target shielding being the most challenging both in terms of technological and safety issues.

  11. Estimation of Radiation Protection Shielding for a EURISOL Linear Proton Accelerator

    E-Print Network [OSTI]

    Thomas Otto, CERN

    A linear accelerator for protons, based on superconducting radiofrequency technology, is envisaged as a driver accelerator for the isotope production targets in a future EURISOL facility. This note reports basic estimates of the required radiation protection shielding of such an accelerator.

  12. Radiation shielding of high-energy neutrons in SAD P. Seltborg1

    E-Print Network [OSTI]

    , A. Lopatkin3 , W. Gudowski1 , V. Shvetsov2 1 Department of Nuclear and Reactor Physics Albanova of the shielding. Consequently, the effec- tive dose above the SAD reactor system is merely dependent on the proton (Karlsruhe) and KTH (Stockholm), the various con- cepts and the basic physical principles of accelerator

  13. An Evaluation of Shadow Shielding for Lunar System Waste Heat Rejection 

    E-Print Network [OSTI]

    Worn, Cheyn

    2012-07-16T23:59:59.000Z

    force the radiator to expand in size and mass to compensate. On the Moon, there are three types: surface infrared, solar insulation, and albedo. This thesis tests shadow shielding geometry and its effect on the radiator and nuclear reactor in a reactor...

  14. Neutron and gamma radiation shielding material, structure, and process of making structure

    DOE Patents [OSTI]

    Hondorp, Hugh L. (Princeton Junction, NJ)

    1984-01-01T23:59:59.000Z

    The present invention is directed to a novel neutron and gamma radiation elding material consisting of 95 to 97 percent by weight SiO.sub.2 and 5 to 3 percent by weight sodium silicate. In addition, the method of using this composition to provide a continuous neutron and gamma radiation shielding structure is disclosed.

  15. Shielding Effectiveness Density Theory for Carbon Fiber/ Nylon 6,6 Composites

    E-Print Network [OSTI]

    Perger, Warren F.

    resistivity (1/electrical conductivity) values for various materials are typically 1014 to 1017 for polymers to improving the electri- cal conductivity of a polymer is through the addition of a conductive filler materialShielding Effectiveness Density Theory for Carbon Fiber/ Nylon 6,6 Composites Jason M. Keith

  16. An Evaluation of Shadow Shielding for Lunar System Waste Heat Rejection

    E-Print Network [OSTI]

    Worn, Cheyn

    2012-07-16T23:59:59.000Z

    force the radiator to expand in size and mass to compensate. On the Moon, there are three types: surface infrared, solar insulation, and albedo. This thesis tests shadow shielding geometry and its effect on the radiator and nuclear reactor in a reactor...

  17. Neutral shells and their applications in the design of electromagnetic shields

    E-Print Network [OSTI]

    Liu, Liping

    , biomedical re- search laboratories, continuous beam accelerators, and various facilities such as transformer for field expelling or confinement are necessary for the reliable working of many electronic devices to these examples, electromagnetic shields are commonly used in advanced nanotechnology research facilities

  18. Optimization and Numerical Simulation of the Cycling Process and Magnetic Shielding of a Miniature Adiabatic

    E-Print Network [OSTI]

    Timbie, Peter

    , which is crucial to minimize stray magnetic fields that could interfere with other refrigerator stagesOptimization and Numerical Simulation of the Cycling Process and Magnetic Shielding of a Miniature Adiabatic Demagnetization Refrigerator Benjamin M. Cain May 18, 2004 A Senior Honors Thesis Project Under

  19. PERGAMON Carbon 39 (2001) 279285 Electromagnetic interference shielding effectiveness of carbon

    E-Print Network [OSTI]

    Chung, Deborah D.L.

    in composite materials, especially after electroplating with nickel. Flexible graphite is attractive for EMI, trons in them. Metal sheets are bulky, so metal coatings made by electroplating, electroless plating / Carbon 39 (2001) 279­285 A secondary mechanism of EMI shielding is usually small value of d for nickel

  20. Turbo Pump Magnetic Shielding Analysis NSTX-CALC-24-04-00

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    NSTX Turbo Pump Magnetic Shielding Analysis NSTX-CALC-24-04-00 March 16, 2011 Prepared By turbo pump to reduce the fringe field from NSTX coils at the pump location to below 50 gauss to be at least 12 inches longer than the pump (6 inches above the top and below the bottom of the turbo pump

  1. Effect of hydrogen in an argon GTAW shielding gas: Arc characteristics and bead morphology

    SciTech Connect (OSTI)

    Onsoeien, M.; Olson, D.L.; Liu, S. (Colorado School of Mines, Golden, CO (United States). Center for Welding and Joining Research); Peters, R. (Delft Technological Univ. (Netherlands))

    1995-01-01T23:59:59.000Z

    The influence of hydrogen additions to an argon shielding gas on the heat input and weld bead morphology was investigated using the gas tungsten arc welding process. Variations in weld bead size and shape with hydrogen additions were related to changes in the ability of the arc to generate heat and not to generate perturbations in the weld pool caused by Marangoni fluid flow.

  2. Calibration of a single atom detector for atomic micro chips

    E-Print Network [OSTI]

    A. Stibor; S. Kraft; T. Campey; D. Komma; A. Günther; J. Fortágh; C. J. Vale; H. Rubinsztein-Dunlop; C. Zimmermann

    2007-02-13T23:59:59.000Z

    We experimentally investigate a scheme for detecting single atoms magnetically trapped on an atom chip. The detector is based on the photoionization of atoms and the subsequent detection of the generated ions. We describe the characterization of the ion detector with emphasis on its calibration via the correlation of ions with simultaneously generated electrons. A detection efficiency of 47.8% (+-2.6%) is measured, which is useful for single atom detection, and close to the limit allowing atom counting with sub-Poissonian uncertainty.

  3. A microfabricated atomic clock

    SciTech Connect (OSTI)

    Knappe, Svenja; Shah, Vishal; Schwindt, Peter D.D.; Hollberg, Leo; Kitching, John; Liew, Li-Anne; Moreland, John [Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305-3328 (United States); Electromagnetics Division, National Institute of Standards and Technology, Boulder, Colorado 80305-3328 (United States)

    2004-08-30T23:59:59.000Z

    Fabrication techniques usually applied to microelectromechanical systems (MEMS) are used to reduce the size and operating power of the core physics assembly of an atomic clock. With a volume of 9.5 mm{sup 3}, a fractional frequency instability of 2.5x10{sup -10} at 1 s of integration, and dissipating less than 75 mW of power, the device has the potential to bring atomically precise timing to hand-held, battery-operated devices. In addition, the design and fabrication process allows for wafer-level assembly of the structures, enabling low-cost mass-production of thousands of identical units with the same process sequence, and easy integration with other electronics.

  4. Delay in Atomic Photoionization

    SciTech Connect (OSTI)

    Kheifets, A. S. [Research School of Physical Sciences, Australian National University, Canberra ACT 0200 (Australia); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106-4030 (United States); Ivanov, I. A. [Research School of Physical Sciences, Australian National University, Canberra ACT 0200 (Australia)

    2010-12-03T23:59:59.000Z

    We analyze the time delay between emission of photoelectrons from the outer valence ns and np subshells in noble gas atoms following absorption of an attosecond extreme ultraviolet pulse. Various processes such as elastic scattering of the photoelectron on the parent ion and many-electron correlation affect the apparent 'time zero' when the photoelectron leaves the atom. This qualitatively explains the time delay between photoemission from the 2s and 2p subshells of Ne as determined experimentally by attosecond streaking [Science 328, 1658 (2010)]. However, with our extensive numerical modeling, we were only able to account for less than half of the measured time delay of 21{+-}5 as. We argue that the extreme ultraviolet pulse alone cannot produce such a large time delay and it is the streaking IR field that is most likely responsible for this effect.

  5. Construction of a Post-Irradiated Fuel Examination Shielded Enclosure Facility

    SciTech Connect (OSTI)

    Michael A. Lehto, Ph.D.; Boyd D. Christensen

    2008-05-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) has committed to provide funding to the Idaho National Laboratory (INL) for new post-irradiation examination (PIE) equipment in support of advanced fuels development. This equipment will allow researchers at the INL to accurately characterize the behavior of experimental test fuels after they are removed from an experimental reactor also located at the INL. The accurate and detailed characterization of the fuel from the reactor, when used in conjunction with computer modeling, will allow DOE to more quickly understand the behavior of the fuel and to guide further development activities consistent with the missions of the INL and DOE. Due to the highly radioactive nature of the specimen samples that will be prepared and analyzed by the PIE equipment, shielded enclosures are required. The shielded cells will be located in the existing Analytical Laboratory (AL) basement (Rooms B-50 and B-51) at the INL Material and Fuels Complex (MFC). AL Rooms B-50 and B-51 will be modified to establish an area where sample containment and shielding will be provided for the analysis of radioactive fuels and materials while providing adequate protection for personnel and the environment. The area is comprised of three separate shielded cells for PIE instrumentation. Each cell contains an atmosphere interface enclosure (AIE) for contamination containment. The shielding will provide a work area consistent with the as-low-as-reasonably-achievable (ALARA) concept, assuming a source term of 10 samples in each of the three shielded areas. Source strength is assumed to be a maximum of 3 Ci at 0.75 MeV gamma for each sample. Each instrument listed below will be installed in an individual shielded enclosure: Shielded electron probe micro-analyzer (EPMA) Focused ion beam instrument (FIB) Micro-scale x-ray diffractometer (MXRD). The project is designed and expected to be built incrementally as funds are allocated. The initial phase will be to fund the construction activities, which will include facility modifications and construction of one shielded enclosure. Follow-up activities will be to construct two additional shielded enclosures to complete the suite of three separate but connected remote operated examination areas. Equipment purchases are to be capital procurement spread out over several years on a funded schedule. This paper discusses safety and operational considerations given during the conceptual design phase of the project. The paper considers such things as project material at risk (MAR), new processes and equipment, potential hazards, and the major modification evaluation process to determine if a preliminary Documented Safety Analysis (PDSA) is required. As part of that process, an evaluation was made of the potential hazards with the new project compared to the existing and historical work and associated hazards in the affected facility.

  6. Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions

    SciTech Connect (OSTI)

    Mahnken, Andreas H., E-mail: mahnken@rad.rwth-aachen.de [RWTH Aachen, Department of Diagnostic and Interventional Radiology (Germany); Sedlmair, Martin [Siemens, Healthcare Sector (Germany); Ritter, Christine [University of Copenhagen, Niels Bohr Institute (Denmark); Banckwitz, Rosemarie; Flohr, Thomas [Siemens, Healthcare Sector (Germany)

    2012-12-15T23:59:59.000Z

    Purpose: Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient. Material and Methods: All examinations were performed with a 128-slice dual source CT scanner (12 Multiplication-Sign 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement. Results: On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner's isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at {>=}150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r{sup 2} = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product. Conclusion: Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.

  7. If you have a Blue Cross Blue Shield of Massachusetts health plan, we've got a healthy incentive for you.

    E-Print Network [OSTI]

    Stoiciu, Mihai

    If you have a Blue Cross Blue Shield of Massachusetts health plan, we've got a healthy incentive for you. As a Blue Cross Blue Shield of Massachusetts subscriber your Fitness Benefit can save you or your Benefit after you've belonged to your health club and been a Blue Cross Blue Shield of Massachusetts

  8. If you have a Blue Cross Blue Shield of Massachusetts health plan, we've got a healthy incentive for you.

    E-Print Network [OSTI]

    Stoiciu, Mihai

    If you have a Blue Cross Blue Shield of Massachusetts health plan, we've got a healthy incentive for you. As a subscriber to Blue Cross Blue Shield of Massachusetts, your Weight Loss Benefit can save you the qualified program in which you enroll. Receipts must show the Blue Cross Blue Shield of Massachusetts member

  9. Optics and interferometry with atoms and molecules

    E-Print Network [OSTI]

    Cronin, Alexander D.

    Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic ...

  10. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisiting the TWP TWPAlumni AlumniFederalAshley BoyleAn overhead viewAtom-split it

  11. MODELING HEAT TRANSFER IN SPENT FUEL TRANSFER CASK NEUTRON SHIELDS – A CHALLENGING PROBLEM IN NATURAL CONVECTION

    SciTech Connect (OSTI)

    Fort, James A.; Cuta, Judith M.; Bajwa, C.; Baglietto, E.

    2010-07-18T23:59:59.000Z

    In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 10-15 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper proposes that there may be reliable CFD approaches to the transfer cask problem, specifically coupled steady-state solvers or unsteady simulations; however, both of these solutions take significant computational effort. Segregated (uncoupled) steady state solvers that were tested did not accurately capture the flow field and heat transfer distribution in this application. Mesh resolution, turbulence modeling, and the tradeoff between steady state and transient solutions are addressed. Because of the critical nature of this application, the need for new experiments at representative scales is clearly demonstrated.

  12. Atomic Energy Commission Takes Over Responsibility for all Atomic...

    National Nuclear Security Administration (NNSA)

    Takes Over Responsibility for all Atomic Energy Programs | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile...

  13. Quantum transport in ultracold atoms

    E-Print Network [OSTI]

    Chih-Chun Chien; Sebastiano Peotta; Massimiliano Di Ventra

    2015-04-11T23:59:59.000Z

    Ultracold atoms confined by engineered magnetic or optical potentials are ideal systems for studying phenomena otherwise difficult to realize or probe in the solid state because their atomic interaction strength, number of species, density, and geometry can be independently controlled. This review focuses on quantum transport phenomena in atomic gases that mirror and oftentimes either better elucidate or show fundamental differences with those observed in mesoscopic and nanoscopic systems. We discuss significant progress in performing transport experiments in atomic gases, contrast similarities and differences between transport in cold atoms and in condensed matter systems, and survey inspiring theoretical predictions that are difficult to verify in conventional setups. These results further demonstrate the versatility offered by atomic systems in the study of nonequilibrium phenomena and their promise for novel applications.

  14. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOE Patents [OSTI]

    Cookson, A.H.; Dale, S.J.; Bolin, P.C.

    1982-12-28T23:59:59.000Z

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections. 10 figs.

  15. Study on eddy current losses and shielding measures in large power transformers

    SciTech Connect (OSTI)

    Chen Yongbin; Yu Hainian [Shenyang Transformer Research Inst. (China)] [Shenyang Transformer Research Inst. (China); Yang Junyou; Tang Renyuan [Shenyang Polytechnic Univ. (China)] [Shenyang Polytechnic Univ. (China)

    1994-09-01T23:59:59.000Z

    The improved T-{Omega} method is applied to the computation of the three dimensional eddy current field in a 360MVA/500kV large power transformer, the structure of which is complicated. The different cases of tank wall with magnetic shunt, aluminum screen or without any shield are analyzed. The relations between eddy current losses and the materials, structure and size of the tank shield are presented. Compared with a parallel magnetic shunt arrangement, the vertical magnetic shunt reduces stray losses by 63.8%. The optimal thickness or the vertical magnetic shunt Is 10mm. The magnetic shunt should be spread over 0.5mm at both ends of windings in the 360MVA/500kV large power transformer.

  16. Nucleonic analysis of the ETF neutral-beam-injector-duct and vacuum-pumping-duct shields

    SciTech Connect (OSTI)

    Urban, W.T.; Seed, T.J.; Dudziak, D.J.

    1981-05-01T23:59:59.000Z

    A nucleonic analysis of the Engineering Test Facility neutral-beam-injector-duct and vacuum-pumping-duct shields has been made using a hybrid Monte Carlo/discrete-ordinates method. This method used Monte Carlo to determine internal and external boundary surface sources for subsequent discrete-ordinates calculations of the neutron and gamma-ray transport through the shields. Confidence was provided in both the hybrid method and the results obtained through a comparison with three-dimensional Monte Carlo results. Also determined in the analysis were the energy and angular distributions of neutrons and gamma rays entering the neutral-beam-injector duct from the toroidal plasma chamber, as well as exiting the duct into the neutral-beam-injector chamber. In addition, the energy and angular distributions of neutrons entering the vacuum-pumping chamber were determined.

  17. Nuclear Rocket Test Facility Decommissioning Including Controlled Explosive Demolition of a Neutron-Activated Shield Wall

    SciTech Connect (OSTI)

    Michael Kruzic

    2007-09-01T23:59:59.000Z

    Located in Area 25 of the Nevada Test Site, the Test Cell A Facility was used in the 1960s for the testing of nuclear rocket engines, as part of the Nuclear Rocket Development Program. The facility was decontaminated and decommissioned (D&D) in 2005 using the Streamlined Approach For Environmental Restoration (SAFER) process, under the Federal Facilities Agreement and Consent Order (FFACO). Utilities and process piping were verified void of contents, hazardous materials were removed, concrete with removable contamination decontaminated, large sections mechanically demolished, and the remaining five-foot, five-inch thick radiologically-activated reinforced concrete shield wall demolished using open-air controlled explosive demolition (CED). CED of the shield wall was closely monitored and resulted in no radiological exposure or atmospheric release.

  18. Integrity evaluation of lower thermal shield under exposure to HFBR environment

    SciTech Connect (OSTI)

    Kassir, M.; Weeks, J.; Bandyopadhyay, K. [Brookhaven National Lab., Upton, NY (United States); Shewmon, P. [Ohio State Univ., Columbus, OH (United States)

    1998-01-01T23:59:59.000Z

    The effects of exposure to the HFBR environment on the carbon steel in the HFBR lower thermal shield were evaluated. Corrosion was found to be a non-significant degradation process. Radiation embrittlement has occurred; portions of the plate closest to the reactor are currently operating in the lower-shelf region of the Charpy impact curve (i.e., below the fracture toughness transition temperature). In this region, the effects of radiation on the mechanical properties of carbon steel are believed to have been saturated, so that no further deterioration is anticipated. A fracture toughness analysis shows that a large factor of safety (> 1.5) exists against propagation of credible hypothetical flaws. Therefore, the existing lower thermal shield structure is suitable for continued operation of the HFBR.

  19. A magnetically shielded room with ultra low residual field and gradient

    SciTech Connect (OSTI)

    Altarev, I.; Chesnevskaya, S.; Gutsmiedl, E.; Kuchler, F.; Lins, T.; Marino, M.; McAndrew, J.; Niessen, B.; Paul, S.; Petzoldt, G.; Singh, J.; Stoepler, R.; Stuiber, S.; Sturm, M.; Taubenheim, B. [Physikdepartment, Technische Universität München, D-85748 Garching (Germany); Babcock, E. [Jülich Center for Neutron Science, Lichtenbergstrasse 1, D-85748 Garching (Germany); Beck, D.; Sharma, S. [Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Burghoff, M.; Fan, I. [Physikalisch-Technische Bundesanstalt Berlin, D-10587 Berlin (Germany); and others

    2014-07-15T23:59:59.000Z

    A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.

  20. Magnetic shielding of the channel walls in a Hall plasma accelerator

    SciTech Connect (OSTI)

    Mikellides, Ioannis G.; Katz, Ira; Hofer, Richard R.; Goebel, Dan M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States); Grys, Kristi de; Mathers, Alex [Aerojet, Redmond, Washington 98052 (United States)

    2011-03-15T23:59:59.000Z

    In a qualification life test of a Hall thruster it was found that the erosion of the acceleration channel practically stopped after {approx}5600 h. Numerical simulations using a two-dimensional axisymmetric plasma solver with a magnetic field-aligned mesh reveal that when the channel receded from its early-in-life to its steady-state configuration the following changes occurred near the wall: (1) reduction of the electric field parallel to the wall that prohibited ions from acquiring significant impact kinetic energy before entering the sheath, (2) reduction of the potential fall in the sheath that further diminished the total energy ions gained before striking the material, and (3) reduction of the ion number density that decreased the flux of ions to the wall. All these changes, found to have been induced by the magnetic field, constituted collectively an effective shielding of the walls from any significant ion bombardment. Thus, we term this process in Hall thrusters 'magnetic shielding'.

  1. Process for producing an aggregate suitable for inclusion into a radiation shielding product

    DOE Patents [OSTI]

    Lessing, Paul A. (Idaho Falls, ID); Kong, Peter C. (Idaho Falls, ID)

    2000-01-01T23:59:59.000Z

    The present invention is directed to methods for converting depleted uranium hexafluoride to a stable depleted uranium silicide in a one-step reaction. Uranium silicide provides a stable aggregate material that can be added to concrete to increase the density of the concrete and, consequently, shield gamma radiation. As used herein, the term "uranium silicide" is defined as a compound generically having the formula U.sub.x Si.sub.y, wherein the x represents the molecules of uranium and the y represent the molecules of silicon. In accordance with the present invention, uranium hexafluoride is converted to a uranium silicide by contacting the uranium hexafluoride with a silicon-containing material at a temperature in a range between about 1450.degree. C. and about 1750.degree. C. The stable depleted uranium silicide is included as an aggregate in a radiation shielding product, such as a concrete product.

  2. Radiation Protection Study for the Shielding Design of the LINAC4 Beam Dump at CERN

    E-Print Network [OSTI]

    Blaha, Jan

    2013-01-01T23:59:59.000Z

    The aim of this study is to determine an optimal shielding of the LINAC4 beam dump fulfilling the radiation protection requirements. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities, such as particle fluences, neutron energy spectra, residual and prompt dose rates, air and water activation have been evaluated for different LINAC4 operation phases.

  3. Analysis of the conceptual shielding design for the upflow Gas-Cooled Fast Breeder Reactor

    SciTech Connect (OSTI)

    Slater, C.O.; Reed, D.A.; Cramer, S.N.; Emmett, M.B.; Tomlinson, E.T.

    1981-01-01T23:59:59.000Z

    Conceptual Shielding Configuration III for the Gas-Cooled Fast Breeder Reactor (GCFR) was analyzed by performing global calculations of neutron and gamma-ray fluences and correcting the results as appropriate with bias factors from localized calculations. Included among the localized calculations were the radial and axial cell streaming calculations, plus extensive preliminary calculations and three final confirmation calculations of the plenum flow-through shields. The global calculations were performed on the GCFR mid-level and the lower and upper plenum regions. Calculated activities were examined with respect to the design constraint, if any, imposed on the particular activity. The spatial distributions of several activities of interest were examined with the aid of isoplots (i.e., symbols are used to describe a surface on which the activity level is everywhere the same). In general the results showed that most activities were below the respective design constraints. Only the total neutron fluence in the core barrel appeared to be marginal with the present reactor design. Since similar results were obtained for an earlier design, it has been proposed that the core barrel be cooled with inlet plenum gas to maintain it at a temperature low enough that it can withstand a higher fluence limit. Radiation levels in the prestressed concrete reactor vessel (PCRV) and liner appeared to be sufficiently below the design constraint that expected results from the Radial Shield Heterogeneity Experiment should not force any levels above the design constraint. A list was also made of a number of issues which should be examined before completion of the final shielding design.

  4. TXSAMC (transport cross sections from applied Monte Carlo): a new tool for generating shielded multigroup cross sections 

    E-Print Network [OSTI]

    Hiatt, Matthew Torgerson

    2009-06-02T23:59:59.000Z

    This thesis describes a tool called TXSAMC (Transport Cross Sections from Applied Monte Carlo) that produces shielded and homogenized multigroup cross sections for small fast reactor systems. The motivation for this tool comes from a desire...

  5. SHIELDING AND DETECTOR RESPONSE CALCULATIONS PERTAINING TO CATEGORY 1 QUANTITIES OF PLUTONIUM AND HAND-HELD PLASTIC SCINTILLATORS

    SciTech Connect (OSTI)

    Couture, A.

    2013-06-07T23:59:59.000Z

    Nuclear facilities sometimes use hand-held plastic scintillator detectors to detect attempts to divert special nuclear material in situations where portal monitors are impractical. MCNP calculations have been performed to determine the neutron and gamma radiation field arising from a Category I quantity of weapons-grade plutonium in various shielding configurations. The shields considered were composed of combinations of lead and high-density polyethylene such that the mass of the plutonium plus shield was 22.7 kilograms. Monte-Carlo techniques were also used to determine the detector response to each of the shielding configurations. The detector response calculations were verified using field measurements of high-, medium-, and low- energy gamma-ray sources as well as a Cf-252 neutron source.

  6. DETERMINING THE OPTIMUM PLACEMENT OF A PHASE CHANGE MATERIALS (PCM) THERMAL SHIELD INSIDE FRAME WALLS USING A DYNAMIC WALL SIMULATOR

    E-Print Network [OSTI]

    Reshmeen, Silvia

    2009-12-23T23:59:59.000Z

    ABSTRACT This thesis presents the results of an experimental study to determine the optimum placement and the thermal performance of a Phase Change Materials (PCMs) thermal shield incorporated into frame wall insulation systems for the purpose...

  7. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect (OSTI)

    Sherrell, D.L.

    1992-06-01T23:59:59.000Z

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  8. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect (OSTI)

    Sherrell, D.L.

    1992-06-01T23:59:59.000Z

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy`s (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE`s Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford`s MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford`s calculations assume five times the GPHS inventory of that assumed for Mound.

  9. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect (OSTI)

    Sherrell, D.L. (Westinghouse Hanford Company, P.O. Box 1970, Mail Stop N1-42, Richland, Washington 99352 (United States))

    1993-01-15T23:59:59.000Z

    A shielded storage rack has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the U.S. Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which processes and stores assembled GPHS modules, prior to their installation into RTGs. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  10. Characterization of TFTR shielding penetrations of ITER-relevance in D-T neutron field

    SciTech Connect (OSTI)

    Kumar, A.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States); Kugel, H.W. [Princeton Univ., NJ (United States)

    1994-12-31T23:59:59.000Z

    D-T operation of TFTR began successfully with trace tritium discharges in mid-November 1993. During the next year, the TFTR plasma tritium fraction is scheduled to be increased to at least 50%. The availability of larger amounts of D-T fusion neutrons in the high power D-T plasma phase of TFTR provides a useful opportunity to characterize tokamak shielding-penetration geometries of potential interest to ITER. These types of measurements can provide direct experimental data on the degree of enhancement of transmitted neutron flux along or across a realistic penetration and, as such, can be used to validate, calculational methods and to meet fusion reactor licensing requirements. The enhancement of neutron streaming in the shielding penetrations has the following significant consequences from the ITER viewpoint: (1) increased radiation damage to plasma diagnostics/detectors, (2) increased biological dose rates behind the shield, (3) increased radiation damage to the superconducting magnet on the inboard side. TFTR has penetrations of different varieties inside the vacuum vessel, the test cell, and the adjoining hot cell. In the initial stage, the authors have chosen to characterize three different types of penetrations in and around the TFTR test cell: (1) a straight hollow pipe coming out of the test cell concrete wall on east side of the test cell into the hot cell, (2) a bent pipe coming out of the test cell through the north concrete wall, and (3) a labyrinth in the north-west end of the test cell.

  11. Using Electronic Neutron Generators in Active Interrogation to Detect Shielded Fissionable Material

    SciTech Connect (OSTI)

    D. L. Chichester; E. H. Seabury

    2008-10-01T23:59:59.000Z

    Experiments have been performed at Idaho National Laboratory to study methodology and instrumentation for performing neutron active interrogation die-away analyses for the purpose of detecting shielded fissionable material. Here we report initial work using a portable DT electronic neutron generator with a He-3 fast neutron detector to detect shielded fissionable material including >2 kg quantities of enriched uranium and plutonium. Measurements have been taken of bare material as well as of material hidden within a large plywood cube. Results from this work have demonstrated the efficacy of the die-away neutron measurement technique for quickly detecting the presence of special nuclear material hidden within plywood shields by analyzing the time dependent neutron signals in-between neutron generator pulses. Using a DT electronic neutron generator operating at 300 Hz with a yield of approximately 0.36 x 10**8 neutrons per second, 2.2 kg of enriched uranium hidden within a 0.60 m x 0.60 m x 0.70 m volume of plywood was positively detected with a measurement signal 2-sigma above the passive background within 1 second. Similarly, for a 500 second measurement period a lower detection limit of approaching the gram level could be expected with the same simple set-up.

  12. MicroShield analysis to calculate external radiation dose rates for several spent fuel casks

    SciTech Connect (OSTI)

    Marincel, M.K. [Missouri Univ., Rolla, MO (United States); Weiner, R.F.; Osborn, D.M. [Sandia National Laboratories, Albuquerque, NM (United States)

    2007-07-01T23:59:59.000Z

    The purpose of this MicroShield analysis is to calculate the external radiation, primarily gamma, dose rate for spent fuel casks. The reason for making this calculation is that currently all analyses of transportation risk assume that this external dose rate is the maximum allowed by regulation, 10 mrem/hr at 2 m from the casks, and the risks of incident-free transportation are thus always overestimated to an unknown extent. In order to do this, the program by Grove Software, MicroShield 7.01, was used to model three Nuclear Regulatory Commission (NRC) approved casks: HI-STAR 100, GA-4, and NAC-STC, loaded with specific source material. Dimensions were obtained from NUREG/CR-6672 and the Certificates of Compliance for each respective cask. Detectors were placed at the axial point at 1 m and 2 m from the outer gamma shielding of the casks. In the April 8, 2004 publication of the Federal Register, a notice of intent to prepare a Supplemental Yucca Mountain Environmental Impact Statement (DOE/EIS-0250F-S1) was published by the Office of Civilian Radioactive Waste Management (OCRWM) in order to consider design, construction, operation, and transportation of spent nuclear fuel to the Yucca Mountain repository [1]. These more accurate estimates of the external dose rates could be used in order to provide a more risk-informed analysis. (authors)

  13. Modeling resonance interference by 0-D slowing-down solution with embedded self-shielding method

    SciTech Connect (OSTI)

    Liu, Y.; Martin, W. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI, 48109 (United States); Kim, K. S.; Williams, M. [Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN 37831-6172 (United States)

    2013-07-01T23:59:59.000Z

    The resonance integral table based methods employing conventional multigroup structure for the resonance self-shielding calculation have a common difficulty on treating the resonance interference. The problem arises due to the lack of sufficient energy dependence of the resonance cross sections when the calculation is performed in the multigroup structure. To address this, a resonance interference factor model has been proposed to account for the interference effect by comparing the interfered and non-interfered effective cross sections obtained from 0-D homogeneous slowing-down solutions by continuous-energy cross sections. A rigorous homogeneous slowing-down solver is developed with two important features for reducing the calculation time and memory requirement for practical applications. The embedded self-shielding method (ESSM) is chosen as the multigroup resonance self-shielding solver as an integral component of the interference method. The interference method is implemented in the DeCART transport code. Verification results show that the code system provides more accurate effective cross sections and multiplication factors than the conventional interference method for UO{sub 2} and MOX fuel cases. The additional computing time and memory for the interference correction is acceptable for the test problems including a depletion case with 87 isotopes in the fuel region. (authors)

  14. The magnetic shielding for the neutron decay spectrometer aSPECT

    E-Print Network [OSTI]

    Gertrud Konrad; Fidel Ayala Guardia; Stefan Baeßler; Michael Borg; Ferenc Glück; Werner Heil; Stefan Hiebel; Raquel Munoz Horta; Yury Sobolev

    2014-05-05T23:59:59.000Z

    Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magnet system. While the return yoke must reduce the stray magnetic field, the internal magnetic field and its homogeneity should not be affected. As in many cases, the magnetic shielding for aSPECT must manage with limited space. In addition, we must ensure that the additional magnetic forces on the magnet coils are not destructive. In order to determine the most suitable geometry for the magnetic shielding for aSPECT, we simulated a variety of possible geometries and combinations of shielding materials of non-linear permeability. The results of our simulations were checked through magnetic field measurements both with Hall and nuclear magnetic resonance probes. The experimental data are in good agreement with the simulated values: The mean deviation from the simulated exterior magnetic field is (-1.7+/-4.8)%. However, in the two critical regions, the internal magnetic field deviates by 0.2% respectively <1E-4 from the simulated values.

  15. Coherent Atom Optics with fast metastable rare gas atoms

    SciTech Connect (OSTI)

    Grucker, J.; Baudon, J.; Karam, J.-C.; Perales, F.; Vassilev, G.; Ducloy, M. [Laboratoire de Physique des Lasers, Universite Paris 13, Avenue J.B. Clement, 93430-Villetaneuse (France); Bocvarski, V. [Institute of Physics, Pregrevica 118, 11080 - Belgrade-Zemun (Serbia and Montenegro)

    2006-12-01T23:59:59.000Z

    Coherent atom optics experiments making use of an ultra-narrow beam of fast metastable atoms generated by metastability exchange are reported. The transverse coherence of the beam (coherence radius of 1.7 {mu}m for He*, 1.2 {mu}m for Ne*, 0.87 {mu}m for Ar*) is demonstrated via the atomic diffraction by a non-magnetic 2{mu}m-period reflection grating. The combination of the non-scalar van der Waals (vdW) interaction with the Zeeman interaction generated by a static magnetic field gives rise to ''vdW-Zeeman'' transitions among Zeeman sub-levels. Exo-energetic transitions of this type are observed with Ne*(3P2) atoms traversing a copper micro-slit grating. They can be used as a tunable beam splitter in an inelastic Fresnel bi-prism atom interferometer.

  16. Bogoliubov theory and bosonic atoms

    E-Print Network [OSTI]

    Phan Thanh Nam

    2011-09-13T23:59:59.000Z

    We formulate the Bogoliubov variational principle in a mathematical framework similar to the generalized Hartree-Fock theory. Then we analyze the Bogoliubov theory for bosonic atoms in details. We discuss heuristically why the Bogoliubov energy should give the first correction to the leading energy of large bosonic atoms.

  17. In-situ control system for atomization

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Terpstra, R.L.

    1995-06-13T23:59:59.000Z

    Melt atomizing apparatus comprising a melt supply orifice for supplying the melt for atomization and gas supply orifices proximate the melt supply orifice for supplying atomizing gas to atomize the melt as an atomization spray is disclosed. The apparatus includes a sensor, such as an optical and/or audio sensor, for providing atomization spray data, and a control unit responsive to the sensed atomization spray data for controlling at least one of the atomizing gas pressure and an actuator to adjust the relative position of the gas supply orifice and melt supply in a manner to achieve a desired atomization spray. 3 figs.

  18. Spectral Emission of Moving Atom

    E-Print Network [OSTI]

    J. X. Zheng-Johansson

    2008-03-17T23:59:59.000Z

    A renewed analysis of the H.E. Ives and G.R. Stilwell's experiment on moving hydrogen canal rays (J. Opt. Soc. Am., 1938, v.28, 215) concludes that the spectral emission of a moving atom exhibits always a redshift which informs not the direction of the atom's motion. The conclusion is also evident from a simple energy relation: atomic spectral radiation is emitted as an orbiting electron consumes a portion of its internal energy on transiting to a lower-energy state which however has in a moving atom an additional energy gain; this results in a redshift in the emission frequency. Based on auxiliary experimental information and a scheme for de Broglie particle formation, we give a vigorous elucidation of the mechanism for deceleration radiation of atomic electron; the corresponding prediction of the redshift is in complete agreement with the Ives and Stilwell's experimental formula.

  19. Supersonic coal water slurry fuel atomizer

    DOE Patents [OSTI]

    Becker, Frederick E. (Reading, MA); Smolensky, Leo A. (Concord, MA); Balsavich, John (Foxborough, MA)

    1991-01-01T23:59:59.000Z

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  20. Detection of transient fluorine atoms

    SciTech Connect (OSTI)

    Loge, G.W.; Nereson, N.; Fry, H.A.

    1986-01-01T23:59:59.000Z

    A KrF eximer laser with a fluence of 50 mJ/cm/sup 2/ was used to photolyze either uranium hexafluoride or molecular fluorine, yielding a transient number density of fluorine atoms. The rise and decay of the atomic fluorine density was observed by transient absorption of a 25-..mu..m Pb-salt diode laser. To prevent the diode laser wavelength from drifting out of resonance with the atomic fluorine line, part of the beam was split off and sent through a microwave discharge fluorine atom cell. This allowed a wavelength modulation-feedback technique to be used to lock the diode laser wavelength onto the atomic line. The remaining diode laser beam was made collinear with the eximer laser beam using a LiF window with a 45/sup 0/ angle of incidence to reflect the infrared beam while transmitting most of the uv beam. Using this setup along with a transient digitizer to average between 100 and 200 transient absorption profiles, fluorine atom number densities on the order of 10/sup 14/ cm/sup -3/ in a 1.7 m pathlength were detected. The signals observed were about a factor of two less than expected from known photolysis and atomic fluorine absorption cross-sections. 2 refs., 4 figs.

  1. Anticipating the atom: popular perceptions of atomic power before Hiroshima

    E-Print Network [OSTI]

    d'Emal, Jacques-Andre Christian

    1994-01-01T23:59:59.000Z

    Before Hiroshima made the Bomb an object of popular concern, possible implications and applications of atomic physics had been discussed in the public forum. The new science of X-rays and radium promised the possibilities of unlimited energy...

  2. atomization atomic absorption: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in vacuum. The...

  3. Chemical factors influencing selenium atomization

    E-Print Network [OSTI]

    Buren, Mary Sue

    1980-01-01T23:59:59.000Z

    Atomization. (August 1980) Mary Sue Buren, B, S. , Angelo State University Chairman of Advisory Comm1ttee: Dr. Thomas M. Vickrey Selenium in an acid1c matrix was analyzed using graphite furnace atom1c absorption with Zeeman-effect background correct1on.... Nickel(II} and lanthanum( III) were introduced as matrix modifiers to determine their effect on interferences 1n selenium atom1zation. In add1tion to matr1x mod1ficat1on, surface coating the graphite furnace with z1rconium and tantalum salts was also...

  4. Chemical factors influencing selenium atomization 

    E-Print Network [OSTI]

    Buren, Mary Sue

    1980-01-01T23:59:59.000Z

    Atomization. (August 1980) Mary Sue Buren, B, S. , Angelo State University Chairman of Advisory Comm1ttee: Dr. Thomas M. Vickrey Selenium in an acid1c matrix was analyzed using graphite furnace atom1c absorption with Zeeman-effect background correct1on.... Nickel(II} and lanthanum( III) were introduced as matrix modifiers to determine their effect on interferences 1n selenium atom1zation. In add1tion to matr1x mod1ficat1on, surface coating the graphite furnace with z1rconium and tantalum salts was also...

  5. SU-D-BRE-07: Neutron Shielding Assessment for a Compact Proton Therapy Vault

    SciTech Connect (OSTI)

    Prusator, M; Ahmad, S; Chen, Y [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To perform a neutron shielding assessment of a commercially available compact proton therapy system. Methods: TOPAS (TOol for PArticle Simulation) beta release was used to model beam line components for Mevion S250 proton treatment system the design of which is that the cyclotron is present in the treatment room. Three neutron production sources were taken into account in the simulation. These are the cyclotron, the treatment nozzle and the patient itself, respectively. The cyclotron was modeled as a cylindrical iron target (r =5 cm, length = 8 cm). A water phantom (10 cm ×10 cm ×60 cm) was used to model the patient and various structures (scattering foils, range modulator wheel, applicator and compensator) defaulted in TOPAS were used to model the passive scattering treatment nozzle. Neutron fluences and energy spectra were counted in a spherical scoring geometry per incident proton in 18 angular bins (10 degree each). Fluence to dose conversion factors from ICRU publication 74 were used to acquire neutron ambient dose equivalent H*(10). A point source line of sight model was then used to calculate neutron dose at eight locations beyond shielding barriers. Results: The neutron ambient dose equivalent was calculated at the 8 points of interest around the proton treatment vault. The highest dose was found to be less than 0.781 mSv/year outside south barrier wall. However, the dose is less than 0.05 mSv/year at the control room area of the proton vault. Conclusion: All Points of interest were well under annual dose limits. This suggests that the shielding design of this compact proton therapy system is sufficient for radiation protection purpose. However, it is important to note that the workload and the occupancy factors are direct multipliers for dose calculations beyond the barrier and must be accurately estimated for validation of our results.

  6. Heterogeneous Catalysis on Atomically Dispersed Supported Metals...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction on Multifunctional Pd Catalysts. Heterogeneous Catalysis on Atomically Dispersed Supported Metals: CO2 Reduction...

  7. Calculation of NMR Shielding in Paramagnetic Molecules: Roadmap and Magnetic Couplings

    E-Print Network [OSTI]

    Vaara, Juha; Mareš, Ji?í

    2015-01-01T23:59:59.000Z

    We present a simple derivation of the nuclear shielding in paramagnetic molecules, extendable to strong spin-orbit coupling cases of relevance to lanthanides and actinides, as well as encompassing contributions from excited multiplets. While our general formulation does not need electron paramagnetic resonance parameters, using them a simple and practical expression is obtained for the special case of the zero-field-split ground-state manifold, including magnetic (Zeeman and hyperfine) couplings between the sublevels. The latter method is implemented computationally and applied in the context of first-principles calculations on example Ni(II) and Co(II) complexes.

  8. Nuclear Rocket Facility Decommissioning Project: Controlled Explosive Demolition of Neutron-Activated Shield Wall

    SciTech Connect (OSTI)

    Michael R. Kruzic

    2008-06-01T23:59:59.000Z

    Located in Area 25 of the Nevada Test Site (NTS), the Test Cell A (TCA) Facility (Figure 1) was used in the early to mid-1960s for testing of nuclear rocket engines, as part of the Nuclear Rocket Development Program, to further space travel. Nuclear rocket testing resulted in the activation of materials around the reactors and the release of fission products and fuel particles. The TCA facility, known as Corrective Action Unit 115, was decontaminated and decommissioned (D&D) from December 2004 to July 2005 using the Streamlined Approach for Environmental Restoration (SAFER) process, under the Federal Facility Agreement and Consent Order. The SAFER process allows environmental remediation and facility closure activities (i.e., decommissioning) to occur simultaneously, provided technical decisions are made by an experienced decision maker within the site conceptual site model. Facility closure involved a seven-step decommissioning strategy. First, preliminary investigation activities were performed, including review of process knowledge documentation, targeted facility radiological and hazardous material surveys, concrete core drilling and analysis, shield wall radiological characterization, and discrete sampling, which proved to be very useful and cost-effective in subsequent decommissioning planning and execution and worker safety. Second, site setup and mobilization of equipment and personnel were completed. Third, early removal of hazardous materials, including asbestos, lead, cadmium, and oil, was performed ensuring worker safety during more invasive demolition activities. Process piping was to be verified void of contents. Electrical systems were de-energized and other systems were rendered free of residual energy. Fourth, areas of high radiological contamination were decontaminated using multiple methods. Contamination levels varied across the facility. Fixed beta/gamma contamination levels ranged up to 2 million disintegrations per minute (dpm)/100 centimeters squared (cm2) beta/gamma. Removable beta/gamma contamination levels seldom exceeded 1,000 dpm/100 cm2, but, in railroad trenches on the reactor pad containing soil on the concrete pad in front of the shield wall, the beta dose rates ranged up to 120 milli-roentgens per hour from radioactivity entrained in the soil. General area dose rates were less than 100 micro-roentgens per hour. Prior to demolition of the reactor shield wall, removable and fixed contaminated surfaces were decontaminated to the best extent possible, using traditional decontamination methods. Fifth, large sections of the remaining structures were demolished by mechanical and open-air controlled explosive demolition (CED). Mechanical demolition methods included the use of conventional demolition equipment for removal of three main buildings, an exhaust stack, and a mobile shed. The 5-foot (ft), 5-inch (in.) thick, neutron-activated reinforced concrete shield was demolished by CED, which had never been performed at the NTS.

  9. Self-shielding of a plasma-exposed surface during extreme transient heat loads

    SciTech Connect (OSTI)

    Zielinski, J. J.; Meiden, H. J. van der; Morgan, T. W.; Hoen, M. H. J. 't; De Temmerman, G., E-mail: g.c.detemmerman@differ.nl [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Schram, D. C. [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2014-03-24T23:59:59.000Z

    The power deposition on a tungsten surface exposed to combined pulsed/continuous high power plasma is studied. A study of the correlation between the plasma parameters and the power deposition on the surface demonstrates the effect of particle recycling in the strongly coupled regime. Upon increasing the input power to the plasma source, the energy density to the target first increases then decreases. We suggest that the sudden outgassing of hydrogen particles from the target and their subsequent ionization causes this. This back-flow of neutrals impedes the power transfer to the target, providing a shielding of the metal surface from the intense plasma flux.

  10. The Conceptional Design of the Shielding Layout and Beam Absorber at the PXIE

    SciTech Connect (OSTI)

    Eidelman, Yu.; Kerby, J.; Lebedev, V.; Leibfritz, J.; Leveling, T.; Nagaisev, S.; Stanek, R.; /Fermilab

    2012-05-14T23:59:59.000Z

    Project X is a high intensity proton facility conceived to support a world-leading physics program at Fermilab. Project X will provide high intensity beams for neutrino, kaon, muon, and nuclei based experiments and for studies supporting energy applications. The Project X Injector Experiment (PIXIE) is a prototype of the Project X front end. A 30 MeV 50 kW beam will be used to validate the design concept of the Project X. This paper discusses a design of the accelerator enclosure radiation shielding and the beam dump.

  11. New Shielding Is Designed to Put the Block on Neutrons | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011R - 445Reports ChartNewShielding Is

  12. Imaging atoms in 3-D

    ScienceCinema (OSTI)

    Ercius, Peter

    2014-06-27T23:59:59.000Z

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  13. Imaging atoms in 3-D

    SciTech Connect (OSTI)

    Ercius, Peter

    2013-10-31T23:59:59.000Z

    Berkeley Lab's Peter Ercius discusses "Imaging atoms in 3-D" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas

  14. RSMASS-D models: An improved method for estimating reactor and shield mass for space reactor applications

    SciTech Connect (OSTI)

    Marshall, A.C.

    1997-10-01T23:59:59.000Z

    Three relatively simple mathematical models have been developed to estimate minimum reactor and radiation shield masses for liquid-metal-cooled reactors (LMRs), in-core thermionic fuel element (TFE) reactors, and out-of-core thermionic reactors (OTRs). The approach was based on much of the methodology developed for the Reactor/Shield Mass (RSMASS) model. Like the original RSMASS models, the new RSMASS-derivative (RSMASS-D) models use a combination of simple equations derived from reactor physics and other fundamental considerations, along with tabulations of data from more detailed neutron and gamma transport theory computations. All three models vary basic design parameters within a range specified by the user to achieve a parameter choice that yields a minimum mass for the power level and operational time of interest. The impact of critical mass, fuel damage, and thermal limitations are accounted for to determine the required fuel mass. The effect of thermionic limitations are also taken into account for the thermionic reactor models. All major reactor component masses are estimated, as well as instrumentation and control (I&C), boom, and safety system masses. A new shield model was developed and incorporated into all three reactor concept models. The new shield model is more accurate and simpler to use than the approach used in the original RSMASS model. The estimated reactor and shield masses agree with the mass predictions from separate detailed calculations within 15 percent for all three models.

  15. Recent Progress in ultracold atoms

    E-Print Network [OSTI]

    Baltisberger, Jay H.

    , cold gas experiments 2. How to make a BEC out of fermions 3. Recent Progress: Controlling Interaction (Feshbach Resonance) 4. From BCS to BEC: Rotating trap and spin- polarized condensates. 5. Future research and Einstein What is Bose-Einstein condensation (BEC)? #12;300 K to 1 mK 109 atoms 1 mK to 1 mK 108 106 atoms

  16. Absorption properties of identical atoms

    E-Print Network [OSTI]

    Pedro Sancho

    2013-07-31T23:59:59.000Z

    Emission rates and other optical properties of multiparticle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas.

  17. Comparison of analytic Whipple bumper shield ballistic limits with CTH simulations

    SciTech Connect (OSTI)

    Hertel, E.S. Jr.

    1993-05-01T23:59:59.000Z

    A series of CTH simulations were conducted to assess the feasibility of using the hydrodynamic code for debris cloud formation and to predict any damage due to the subsequent loading on rear structures. Six axisymmetric and one 3-dimensional simulations were conducted for spherical projectiles impacting Whipple bumper shields. The projectile diameters were chosen to correlate with two well known analytic expressions for the ballistic limit of a Whipple bumper shield. It has been demonstrated that CTH can be used to simulate the debris cloud formation, the propagation of the debris across a void region, and the secondary impact of the debris against a structure. In addition, the results from the CTH simulations were compared to the analytic estimates of the ballistic limit. At impact velocities of 10 km/s or less, the CTH predicted ballistic limit lays between the two analytic estimates. However, for impact velocities greater than 10 km/s, CTH simulations predicted a ballistic limit larger than both analytical estimates. The differences at high velocities are not well understood. Structural failure at late times due to the time integrated loading of a very diffuse debris cloud has not been considered in the CTH model. In addition, the analytic predictions are extrapolated from relatively low velocity data and the extrapolation technique may not be valid. The discrepancy between the two techniques should be investigated further.

  18. Dendrite-Free Lithium Deposition via Self-Healing Electrostatic Shield Mechanism

    SciTech Connect (OSTI)

    Ding, Fei; Xu, Wu; Graff, Gordon L.; Zhang, Jian; Sushko, Maria L.; Chen, Xilin; Shao, Yuyan; Engelhard, Mark H.; Nie, Zimin; Xiao, Jie; Liu, Xingjiang; Sushko, P. V.; Liu, Jun; Zhang, Jiguang

    2013-02-28T23:59:59.000Z

    Lithium metal batteries are called the “holy grail” of energy storage systems. However, lithium dendrite growth in these batteries has prevented their practical applications in the last 40 years. Here we show a novel mechanism which can fundamentally change the dendritic morphology of lithium deposition. A low concentration of the second cations (including ions of cesium, rubidium, potassium, and strontium) exhibits an effective reduction potential lower than the standard reduction potential of lithium ions when the chemical activities of these second cations are much lower than that of lithium ions. During lithium deposition, these second cations will form a self-healing electrostatic shield around the initial tip of lithium whenever it is formed. This shield will repel the incoming lithium ions and force them to deposit in the smoother region of the anode so a dendrite-free film is obtained. This mechanism is effective on dendrite prevention in both lithium metal and lithium ion batteries. They may also prevent dendrite growth in other metal batteries and have transformational impact on the smooth deposition in general electrodeposition processes.

  19. Pulsed, Photonuclear-induced, Neutron Measurements of Nuclear Materials with Composite Shielding

    SciTech Connect (OSTI)

    James Jones; Kevin Haskell; Rich Waston; William Geist; Jonathan Thron; Corey Freeman; Martyn Swinhoe; Seth McConchie; Eric Sword; Lee Montierth; John Zabriskie

    2011-07-01T23:59:59.000Z

    Active measurements were performed using a 10-MeV electron accelerator with inspection objects containing various nuclear and nonnuclear materials available at the Idaho National Laboratory’s Zero Power Physics Reactor (ZPPR) facility. The inspection objects were assembled from ZPPR reactor plate materials to evaluate the measurement technologies for the characterization of plutonium, depleted uranium or highly enriched uranium shielded by both nuclear and non-nuclear materials. A series of pulsed photonuclear, time-correlated measurements were performed with unshielded calibration materials and then compared with the more complex composite shield configurations. The measurements used multiple 3He detectors that are designed to detect fission neutrons between pulses of an electron linear accelerator. The accelerator produced 10-MeV bremsstrahlung X-rays at a repetition rate of 125 Hz (8 ms between pulses) with a 4-us pulse width. All inspected objects were positioned on beam centerline and 100 cm from the X-ray source. The time-correlated data was collected in parallel using both a Los Alamos National Laboratory-designed list-mode acquisition system and a commercial multichannel scaler analyzer. A combination of different measurement configurations and data analysis methods enabled the identification of each object. This paper describes the experimental configuration, the ZPPR inspection objects used, and the various measurement and analysis results for each inspected object.

  20. Parametric Evaluation of Active Neutron Interrogation for the Detection of Shielded Highly-Enriched Uranium in the Field

    SciTech Connect (OSTI)

    D. L. Chcihester; E. H. Seabury; S. J. Thompson; R. R. C. Clement

    2011-10-01T23:59:59.000Z

    Parametric studies using numerical simulations are being performed to assess the performance capabilities and limits of active neutron interrogation for detecting shielded highly enriched uranium (HEU). Varying the shield material, HEU mass, HEU depth inside the shield, and interrogating neutron source energy, the simulations account for both neutron and photon emission signatures from the HEU with resolution in both energy and time. The results are processed to represent different irradiation timing schemes and several different classes of radiation detectors, and evaluated using a statistical approach considering signal intensity over background. This paper describes the details of the modeling campaign and some preliminary results, weighing the strengths of alternative measurement approaches for the different irradiation scenarios.

  1. Accelerometer using atomic waves for space applications

    E-Print Network [OSTI]

    of Bose-Einstein condensation (BEC) of a dilute gas of trapped atoms in a single quantum state [18, 19, 20 of such devices in the field of navigation, surveying and analysis of earth structures. Matter-wave interferometry that the use of Bose-Einstein condensed atoms will bring the science of atom optics, and in particular atom

  2. Use of depleted uranium metal as cask shielding in high-level waste storage, transport, and disposal systems

    SciTech Connect (OSTI)

    Yoshimura, H.R.; Ludwigsen, J.S.; McAllaster, M.E. [and others

    1996-09-01T23:59:59.000Z

    The US DOE has amassed over 555,000 metric tons of depleted uranium from its uranium enrichment operations. Rather than dispose of this depleted uranium as waste, this study explores a beneficial use of depleted uranium as metal shielding in casks designed to contain canisters of vitrified high-level waste. Two high-level waste storage, transport, and disposal shielded cask systems are analyzed. The first system employs a shielded storage and disposal cask having a separate reusable transportation overpack. The second system employs a shielded combined storage, transport, and disposal cask. Conceptual cask designs that hold 1, 3, 4 and 7 high-level waste canisters are described for both systems. In all cases, cask design feasibility was established and analyses indicate that these casks meet applicable thermal, structural, shielding, and contact-handled requirements. Depleted uranium metal casting, fabrication, environmental, and radiation compatibility considerations are discussed and found to pose no serious implementation problems. About one-fourth of the depleted uranium inventory would be used to produce the casks required to store and dispose of the nearly 15,400 high-level waste canisters that would be produced. This study estimates the total-system cost for the preferred 7-canister storage and disposal configuration having a separate transportation overpack would be $6.3 billion. When credits are taken for depleted uranium disposal cost, a cost that would be avoided if depleted uranium were used as cask shielding material rather than disposed of as waste, total system net costs are between $3.8 billion and $5.5 billion.

  3. Magnetic field dependence of shielding current density in Y-Ba-Cu-O rings at 77 K

    SciTech Connect (OSTI)

    Polak, M.; Majoros, M.; Hanic, F.; Pitel, J.; Kedrova, M.; Kottman, P.; Talapa, J.; Vencel, L. (Center for Electrophysical Research, Dubravska (Czechoslovakia))

    1989-06-01T23:59:59.000Z

    A method for contactless measurement of the shielding critical current density and its dependence on the external magnetic field is described and analyzed. The obtained values are compared with those measured resistively on two different samples. It is shown that the shielding critical current density J{sub cs} and the intergranular transport current density J{sub ct} are identical if the measurement conditions are similar. A degradation of J{sub cs} measured in the external field with AC ripple has been observed.

  4. A 2-D Test Problem for CFD Modeling Heat Transfer in Spent Fuel Transfer Cask Neutron Shields

    SciTech Connect (OSTI)

    Zigh, Ghani; Solis, Jorge; Fort, James A.

    2011-01-14T23:59:59.000Z

    In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 5-10 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper presents results for a simple 2-D problem that is an effective numerical analog for the neutron shield application. Because it is 2-D, solutions can be obtained relatively quickly allowing a comparison and assessment of sensitivity to model parameter changes. Turbulence models are considered as well as the tradeoff between steady state and transient solutions. Solutions are compared for two commercial CFD codes, FLUENT and STAR-CCM+. The results can be used to provide input to the CFD Best Practices for this application. Following study results for the 2-D test problem, a comparison of simulation results is provided for a high Rayleigh number experiment with large annular gap. Because the geometry of this validation is significantly different from the neutron shield, and due to the critical nature of this application, the argument is made for new experiments at representative scales

  5. Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    SciTech Connect (OSTI)

    Cui, Z. Q.; Chen, Z. J.; Xie, X. F.; Peng, X. Y.; Hu, Z. M.; Du, T. F.; Ge, L. J.; Zhang, X.; Yuan, X.; Fan, T. S.; Chen, J. X.; Li, X. Q., E-mail: lixq2002@pku.edu.cn, E-mail: guohuizhang@pku.edu.cn; Zhang, G. H., E-mail: lixq2002@pku.edu.cn, E-mail: guohuizhang@pku.edu.cn [School of Physics, State Key Lab of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Xia, Z. W. [Southwestern Institute of Physics, Chengdu 610225 (China); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, CAS, Hefei 230031 (China)

    2014-11-15T23:59:59.000Z

    The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

  6. Design of the radiation shielding for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    SciTech Connect (OSTI)

    Du, T. F.; Chen, Z. J.; Peng, X. Y.; Yuan, X.; Zhang, X.; Hu, Z. M.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S., E-mail: tsfan@pku.edu.cn [School of Physics, State Key Lab of Nuclear Physics and Technology, Peking University, Beijing (China); Gorini, G.; Nocente, M. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano (Italy); Istituto di Fisicadel Plasma “P. Caldirola,” Milano (Italy); Tardocchi, M. [Istituto di Fisicadel Plasma “P. Caldirola,” Milano (Italy); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, CAS, Hefei (China)

    2014-11-15T23:59:59.000Z

    A radiation shielding has been designed to reduce scattered neutrons and background gamma-rays for the new double-ring Time Of Flight Enhanced Diagnostics (TOFED). The shielding was designed based on simulation with the Monte Carlo code MCNP5. Dedicated model of the EAST tokamak has been developed together with the emission neutron source profile and spectrum; the latter were simulated with the Nubeam and GENESIS codes. Significant reduction of background radiation at the detector can be achieved and this satisfies the requirement of TOFED. The intensities of the scattered and direct neutrons in the line of sight of the TOFED neutron spectrometer at EAST are studied for future data interpretation.

  7. Atomic Cascade in Muonic and Hadronic Hydrogen Atoms

    E-Print Network [OSTI]

    T. S. Jensen; V. P. Popov; V. N. Pomerantsev

    2007-12-18T23:59:59.000Z

    The atomic cascade in $\\mu^- p$ and $\\pi^- p$ atoms has been studied with the improved version of the extended cascade model in which new quantum mechanical calculations of the differential and integral cross sections of the elastic scattering, Stark transitions and Coulomb de-excitation have been included for the principal quantum number values $n\\le 8$ and the relative energies $E \\ge 0.01$ eV. The $X$-ray yields and kinetic energy distributions are compared with the experimental data.

  8. Quantum Electrodynamics of Atomic Resonances

    E-Print Network [OSTI]

    Miguel Ballesteros; Jérémy Faupin; Jürg Fröhlich; Baptiste Schubnel

    2015-03-09T23:59:59.000Z

    A simple model of an atom interacting with the quantized electromagnetic field is studied. The atom has a finite mass $m$, finitely many excited states and an electric dipole moment, $\\vec{d}_0 = -\\lambda_{0} \\vec{d}$, where $\\| d^{i}\\| = 1,$ $ i=1,2,3,$ and $\\lambda_0$ is proportional to the elementary electric charge. The interaction of the atom with the radiation field is described with the help of the Ritz Hamiltonian, $-\\vec{d}_0\\cdot \\vec{E}$, where $\\vec{E}$ is the electric field, cut off at large frequencies. A mathematical study of the Lamb shift, the decay channels and the life times of the excited states of the atom is presented. It is rigorously proven that these quantities are analytic functions of the momentum $\\vec{p}$ of the atom and of the coupling constant $\\lambda_0$, provided $|\\vec{p}| < mc$ and $| \\Im\\vec{p} |$ and $| \\lambda_{0} |$ are sufficiently small. The proof relies on a somewhat novel inductive construction involving a sequence of `smooth Feshbach-Schur maps' applied to a complex dilatation of the original Hamiltonian, which yields an algorithm for the calculation of resonance energies that converges super-exponentially fast.

  9. Degeneracy Breaking of Hydrogen Atom

    E-Print Network [OSTI]

    Agung Trisetyarso; Pantur Silaban

    2014-11-21T23:59:59.000Z

    The three dimensional rotation group, SO(3), is a symmetry group of the normal hydrogen atom. Each reducible representation of this group can be associated with a degenerate energy level. If this atom is placed in an external magnetic field, the interaction between the orbital magnetic moment with this field will lead to a symmetry breaking where the symmetry group of the atom is a new group distinct from the SO(3) group. This phenomenon describes the normal Zeeman effect, where a degenerate energy level splits into several new energy levels. It is explicitly shown that each of the new energy levels can be associated with an irreducible representation of the new symmetry group.

  10. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, Cyril V. (Knoxville, TN); Wise, Marcus B. (Kingston, TN)

    1997-01-01T23:59:59.000Z

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid.

  11. Atomizing, continuous, water monitoring module

    DOE Patents [OSTI]

    Thompson, C.V.; Wise, M.B.

    1997-07-08T23:59:59.000Z

    A system for continuously analyzing volatile constituents of a liquid is described. The system contains a pump for continuously pumping the liquid to be tested at a predetermined flow rate into an extracting container through a liquid directing tube having an orifice at one end and positioned to direct the liquid into the extracting container at a flow rate sufficient to atomize the liquid within the extracting container. A continuous supply of helium carrier gas at a predetermined flow rate is directed through a tube into the extracting container and co-mingled with the atomized liquid to extract the volatile constituents contained within the atomized liquid. The helium containing the extracted volatile constituents flows out of the extracting container into a mass spectrometer for an analysis of the volatile constituents of the liquid. 3 figs.

  12. This A TM contains mate rial on the comparative analysis and de sign of the A LSEP Fuel Cask Thermal Shield. This report is submitted in accor-

    E-Print Network [OSTI]

    Rathbun, Julie A.

    of the fuel cask/LEM/SLA envelope was undertakei?- to determine the specific requirements for a thermal heat envelope was made to select the position an? orientation of the cask thermal shield. Figure 1 shows Thermal Shield. This report ·is submitted in accor- dance with MSC request generated during the System

  13. DEMONSTRATION OF THE GLYCOLIC-FORMIC FLOWSHEET IN THE SRNL SHIELDED CELLS USING ACTUAL WASTE

    SciTech Connect (OSTI)

    Lambert, D.; Pareizs, J.; Click, D.

    2011-11-07T23:59:59.000Z

    Glycolic acid was effective at dissolving many metals, including iron, during processing with simulants. Criticality constraints take credit for the insolubility of iron during processing to prevent criticality of fissile materials. Testing with actual waste was needed to determine the extent of iron and fissile isotope dissolution during Chemical Process Cell (CPC) processing. The Alternate Reductant Project was initiated by the Savannah River Remediation (SRR) Company to explore options for the replacement of the nitric-formic flowsheet used for the CPC at the Defense Waste Processing Facility (DWPF). The goals of the Alternate Reductant Project are to reduce CPC cycle time, increase mass throughput of the facility, and reduce operational hazards. In order to achieve these goals, several different reductants were considered during initial evaluations conducted by Savannah River National Laboratory (SRNL). After review of the reductants by SRR, SRNL, and Energy Solutions (ES) Vitreous State Laboratory (VSL), two flowsheets were further developed in parallel. The two flowsheet options included a nitric-formic-glycolic flowsheet, and a nitric-formic-sugar flowsheet. As of July 2011, SRNL and ES/VSL have completed the initial flowsheet development work for the nitric-formic-glycolic flowsheet and nitric-formic-sugar flowsheet, respectively. On July 12th and July 13th, SRR conducted a Systems Engineering Evaluation (SEE) to down select the alternate reductant flowsheet. The SEE team selected the Formic-Glycolic Flowsheet for further development. Two risks were identified in SEE for expedited research. The first risk is related to iron and plutonium solubility during the CPC process with respect to criticality. Currently, DWPF credits iron as a poison for the fissile components of the sludge. Due to the high iron solubility observed during the flowsheet demonstrations with simulants, it was necessary to determine if the plutonium in the radioactive sludge slurry demonstrated the same behavior. The second risk is related to potential downstream impacts of glycolate on Tank Farm processes. The downstream impacts will be evaluated by a separate research team. Waste Solidification Engineering (WSE) has requested a radioactive demonstration of the Glycolic-Formic Flowsheet with radioactive sludge slurry be completed in the Shielded Cells Facility of the SRNL. The Shielded Cells demonstration only included a Sludge Receipt and Adjustment Tank (SRAT) cycle, and not a Slurry Mix Evaporator (SME) cycle or the co-processing of salt products. Sludge Batch 5 (SB5) slurry was used for the demonstration since it was readily available, had been previously characterized, and was generally representative of sludges being processing in DWPF. This sample was never used in the planned Shielded Cells Run 7 (SC-7).

  14. Nanoplasmonic Lattices for Ultracold atoms

    E-Print Network [OSTI]

    M. Gullans; T. Tiecke; D. E. Chang; J. Feist; J. D. Thompson; J. I. Cirac; P. Zoller; M. D. Lukin

    2014-07-25T23:59:59.000Z

    We propose to use sub-wavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the sub-wavelength manipulation and strong light-matter interaction associated with nano-plasmonic systems. It allows one to considerably increase the energy scales in the realization of Hubbard models and to engineer effective long-range interactions in coherent and dissipative many-body dynamics. Realistic imperfections and potential applications are discussed.

  15. An ultra-bright atom laser

    E-Print Network [OSTI]

    V. Bolpasi; N. K. Efremidis; M. J. Morrissey; P. Condylis; D. Sahagun; M. Baker; W. von Klitzing

    2013-11-25T23:59:59.000Z

    We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just below the condensate. As opposed to traditional atom lasers based on weak coupling, this technique allows us to outcouple atoms at an arbitrarily large rate. We demonstrate an increase in flux per atom in the BEC by a factor of sixteen compared to the brightest quasi-continuous atom laser. Furthermore, we produce by two orders of magnitude the coldest thermal atom beam to date (200 nK).

  16. Vitrification of cesium-loaded crystalline silicotitanate (CST) in the shielded cells melter

    SciTech Connect (OSTI)

    Andrews, M.K. [Westinghouse Savannah River Company, AIKEN, SC (United States); Fellinger, T.L.; Ferrara, D.M.; Harbour, J.R.; Herman, D.T.

    1997-09-30T23:59:59.000Z

    Through the Tanks Focus Area, the Savannah River Technology Center (SRTC) and the Oak Ridge National Laboratory participated in a joint project in which supernate waste from the Melton Valley Storage Tanks at Oak Ridge was treated by passage through a crystalline silicotitanate (CST) ion exchange column. CST was designed to sorb Cs- 137, Sr-90 and several other radionuclides from highly alkaline solutions containing large quantities of sodium.2 After demonstrating the effectiveness of CST as an ion exchange medium, ORNL shipped some of the loaded sorbent to SRTC where it was mixed with glass formers and processed in a joule-heated melter within the SRTC Shielded Cells. This report details the results of the melter run, along with the preparations that were required to complete the campaign.

  17. Thermal transport in boron nitride nanotorus—towards a nanoscopic thermal shield

    SciTech Connect (OSTI)

    Loh, G. C., E-mail: jgloh@mtu.edu [Institute of High Performance Computing, 1 Fusionopolis Way, 16-16 Connexis, Singapore 138632 (Singapore); Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); Baillargeat, D. [CNRS-International-NTU-Thales Research Alliance (CINTRA), 50 Nanyang Drive, Singapore 637553 (Singapore)

    2013-11-14T23:59:59.000Z

    Nanotori, or nanorings, are topological variants of nanotubes and are conceived to have different properties from their tubular form. In this study, the toroidal arrangement of boron nitride is introduced. Using classical molecular dynamics simulations, the thermal behaviour (thermal conductivity and thermal stability) of the boron nitride nanotorus and its relationship with the structural characteristics are investigated. Its circumferential thermal rectification strength displays a linear dependence on the bending coefficient of the nanostructure. Surface kinks are relatively inconsequential on its circumferential mode of conduction, as compared to its axial sense. The circumferential conductivity in the diffusive regime is calculated to be approximately 10?W/m K, while the axial conductivity is more than tenfold of this value. All nanotori with different toroidal characters show excellent thermal stability at extremely high temperatures approaching 3400?K. With consideration to its favourable properties, a thermal shield made up of a parallel row of nanotori is proposed as a nanoscale thermal insulation device.

  18. EURISOL-DS Multi?MW Target: Radiological Protection, Radiation Safety and Shielding Aspects

    E-Print Network [OSTI]

    Y. Romanets and R. Luís (ITN)

    The objective of this work was to carry out a detailed study and analysis of all aspects related toradioprotection and radiation safety of the spallation target area and the whole spaces reservedfor the fission targets and spallation target maintenance. Operational and no?operationalconditions were considered for an evaluation of the radiation safety conditions.An analysis of the proposed shielding dimensions and configuration was performed for thesystem during operation time. Parameters as activation, dose rate, energy deposition, etc. aremore important for the no?operation period, in order to evaluate the hazard level anddetermine the staff access type to the maintenance areas (direct or remote control).Such elements as the fission targets and the whole structure involved on it were studied in moredetail because of the disposal issues, after operation. Activation, dose rate and residual nuclideswere studied for each element of the assembly. All parameters were analyzed according to their...

  19. US ITER (International Thermonuclear Experimental Reactor) shield and blanket design activities

    SciTech Connect (OSTI)

    Baker, C.C.

    1988-08-01T23:59:59.000Z

    This paper summarizes nuclear-related work in support of the US effort for the International Thermonuclear Experimental Reactor (ITER) Study. Primary tasks carried out during the past year include design improvements of the inboard shield developed for the TIBER concept, scoping studies of a variety of tritium breeding blanket options, development of necessary design guidelines and evaluation criteria for the blanket options, further safety considerations related to nuclear components, and issues regarding structural materials for an ITER device. The blanket concepts considered are the aqueous/Li salt solution, a water-cooled, solid breeder blanket, a helium-cooled, solid-breeder blanket, a blanket cooled by helium containing lithium-bearing particulates, and a blanket concept based on breeding tritium from He/sup 3/. 1 ref., 2 tabs.

  20. Thermal insulating barrier and neutron shield providing integrated protection for a nuclear reactor vessel

    DOE Patents [OSTI]

    Schreiber, R.B.; Fero, A.H.; Sejvar, J.

    1997-12-16T23:59:59.000Z

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor. 8 figs.

  1. Thermal insulating barrier and neutron shield providing integrated protection for a nuclear reactor vessel

    DOE Patents [OSTI]

    Schreiber, Roger B. (Penn Twp., PA); Fero, Arnold H. (New Kensington, PA); Sejvar, James (Murrysville, PA)

    1997-01-01T23:59:59.000Z

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor.

  2. Use of fly ash as an admixture for electromagnetic interference shielding Jingyao Cao, D.D.L. Chung*

    E-Print Network [OSTI]

    Chung, Deborah D.L.

    in the United States generate 80 million tons of fly ash as a by-product each year, primarily from coal combustion [1]. Fly ash is typically disposed in landfills, but it is preferred to convert fly ashUse of fly ash as an admixture for electromagnetic interference shielding Jingyao Cao, D.D.L. Chung

  3. An Association of Independent Blue Cross and Blue Shield Plans This health plan meets Minimum Creditable Coverage Standards for

    E-Print Network [OSTI]

    Aalberts, Daniel P.

    An Association of Independent Blue Cross and Blue Shield Plans This health plan meets Minimum, as part of the Massachusetts Health Care Reform Law. HMO Blue New EnglandSM Summary of Benefits Williams College #12;Your Care Your Primary Care Provider. When you enroll in HMO Blue New England, you must choose

  4. EFFECT OF MINOR ADDITIONS OF HYDROGEN TO ARGON SHIELDING GAS WHEN WELDING AUSTENITIC STAINLESS STEEL WITH THE GTAW PROCESS

    SciTech Connect (OSTI)

    CANNELL, G.R.

    2004-12-15T23:59:59.000Z

    This paper provides the technical basis to conclude that the use of hydrogen containing shielding gases during welding of austenitic stainless steels will not lead to hydrogen induced cracking (HIC) of the weld or weld heat affected zone. Argon-hydrogen gas mixtures, with hydrogen additions up to 35% [1], have been successfully used as the shielding gas in gas tungsten arc welding (GTAW) of austenitic stainless steels. The addition of hydrogen improves weld pool wettability, bead shape control, surface cleanliness and heat input. The GTAW process is used extensively for welding various grades of stainless steel and is preferred when a very high weld quality is desired, such as that required for closure welding of nuclear materials packages. The use of argon-hydrogen gas mixtures for high-quality welding is occasionally questioned, primarily because of concern over the potential for HIC. This paper was written specifically to provide a technical basis for using an argon-hydrogen shielding gas in conjunction with the development, at the Savannah River Technology Center (SRTC), of an ''optimized'' closure welding process for the DOE standardized spent nuclear fuel canister [2]. However, the basis developed here can be applied to other applications in which the use of an argon-hydrogen shielding gas for GTAW welding of austenitic stainless steels is desired.

  5. 2013 R&D 100 Award: 'SHIELD' protects NIF optics from harmful pulses

    ScienceCinema (OSTI)

    Chou, Jason

    2014-07-22T23:59:59.000Z

    In the past, it took as long as 12 hours to manually screen 48 critical checkpoints at the National Ignition Facility (NIF) for harmful laser pulses. The screening equipment had to be moved from point to point throughout a facility the size of three football fields. Now with a new technology, called Laser SHIELD (Screening at High-throughput to Identify Energetic Laser Distortion), and with the push of a button, the screening can be done in less than one second. Proper screening of pulses is critical for the operation of high-energy lasers to ensure that the laser does not exceed safe operating conditions for optics. The energetic beams of light are so powerful that, when left uncontrolled, they can shatter the extremely valuable glass inside the laser. If a harmful pulse is found, immediate adjustments can be made in order to protect the optics for the facility. Laser SHIELD is a custom-designed high-throughput screening system built from low-cost and commercially available components found in the telecommunications industry. Its all-fiber design makes it amenable to the unique needs of high-energy laser facilities, including routing to intricate pick-off locations, immunity to electromagnetic interference and low-loss transport (up to several kilometers). The technology offers several important benefits for NIF. First, the facility is able to fire more shots in less time-an efficiency that saves the facility millions of dollars each year. Second, high-energy lasers are more flexible to wavelength changes requested by target physicists. Third, by identifying harmful pulses before they damage the laser's optics, the facility potentially saves hundreds of thousands of dollars in maintenance costs each year.

  6. A NEW ALGORITHM FOR RADIOISOTOPE IDENTIFICATION OF SHIELDED AND MASKED SNM/RDD MATERIALS

    SciTech Connect (OSTI)

    Jeffcoat, R.

    2012-06-05T23:59:59.000Z

    Detection and identification of shielded and masked nuclear materials is crucial to national security, but vast borders and high volumes of traffic impose stringent requirements for practical detection systems. Such tools must be be mobile, and hence low power, provide a low false alarm rate, and be sufficiently robust to be operable by non-technical personnel. Currently fielded systems have not achieved all of these requirements simultaneously. Transport modeling such as that done in GADRAS is able to predict observed spectra to a high degree of fidelity; our research is focusing on a radionuclide identification algorithm that inverts this modeling within the constraints imposed by a handheld device. Key components of this work include incorporation of uncertainty as a function of both the background radiation estimate and the hypothesized sources, dimensionality reduction, and nonnegative matrix factorization. We have partially evaluated performance of our algorithm on a third-party data collection made with two different sodium iodide detection devices. Initial results indicate, with caveats, that our algorithm performs as good as or better than the on-board identification algorithms. The system developed was based on a probabilistic approach with an improved approach to variance modeling relative to past work. This system was chosen based on technical innovation and system performance over algorithms developed at two competing research institutions. One key outcome of this probabilistic approach was the development of an intuitive measure of confidence which was indeed useful enough that a classification algorithm was developed based around alarming on high confidence targets. This paper will present and discuss results of this novel approach to accurately identifying shielded or masked radioisotopes with radiation detection systems.

  7. Magnetic shielding of a laboratory Hall thruster. I. Theory and validation

    SciTech Connect (OSTI)

    Mikellides, Ioannis G., E-mail: Ioannis.G.Mikellides@jpl.nasa.gov; Katz, Ira; Hofer, Richard R.; Goebel, Dan M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-01-28T23:59:59.000Z

    We demonstrate a technique by which erosion of the acceleration channel in Hall thrusters can be reduced by at least a few orders of magnitude. The first principles of the technique, now known as “magnetic shielding,” have been derived based on the findings of 2-D numerical simulations. The simulations, in turn, guided the modification of an existing 6-kW laboratory Hall thruster to test the theory and are the main subject of this Part I article. Part II expands on the results of the experiments. Near the walls of the magnetically shielded (MS) thruster theory and experiment agree that (1) the plasma potential has been sustained at values near the discharge voltage, and (2) the electron temperature has been lowered compared to the unshielded thruster. Erosion rates deduced directly from the wall probes show reductions of at least ?3 orders of magnitude at the MS inner wall when an ion energy threshold of 30.5?V is used in the sputtering yield model of the channel material. At the outer wall the probes reveal that the ion energy was below the assumed threshold. Using a threshold of 25?V, the simulations predict a minimum reduction of ?600 at the MS inner wall. At the MS outer wall ion energies are found to be below 25?V. When a 50-V threshold is used the computed ion energies are below the threshold at both sides of the channel. Uncertainties, sensitivities, and differences between theory and experiment are also discussed. The elimination of wall erosion in Hall thrusters solves a problem that has remained unsettled for more than five decades.

  8. Flow distribution analysis on the cooling tube network of ITER thermal shield

    SciTech Connect (OSTI)

    Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun; Kang, Dong Kwon; Kang, Kyoung-O; Ahn, Hee Jae; Lee, Hyeon Gon [ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-01-29T23:59:59.000Z

    Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube network for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.

  9. 2013 R&D 100 Award: 'SHIELD' protects NIF optics from harmful pulses

    SciTech Connect (OSTI)

    Chou, Jason

    2014-04-03T23:59:59.000Z

    In the past, it took as long as 12 hours to manually screen 48 critical checkpoints at the National Ignition Facility (NIF) for harmful laser pulses. The screening equipment had to be moved from point to point throughout a facility the size of three football fields. Now with a new technology, called Laser SHIELD (Screening at High-throughput to Identify Energetic Laser Distortion), and with the push of a button, the screening can be done in less than one second. Proper screening of pulses is critical for the operation of high-energy lasers to ensure that the laser does not exceed safe operating conditions for optics. The energetic beams of light are so powerful that, when left uncontrolled, they can shatter the extremely valuable glass inside the laser. If a harmful pulse is found, immediate adjustments can be made in order to protect the optics for the facility. Laser SHIELD is a custom-designed high-throughput screening system built from low-cost and commercially available components found in the telecommunications industry. Its all-fiber design makes it amenable to the unique needs of high-energy laser facilities, including routing to intricate pick-off locations, immunity to electromagnetic interference and low-loss transport (up to several kilometers). The technology offers several important benefits for NIF. First, the facility is able to fire more shots in less time-an efficiency that saves the facility millions of dollars each year. Second, high-energy lasers are more flexible to wavelength changes requested by target physicists. Third, by identifying harmful pulses before they damage the laser's optics, the facility potentially saves hundreds of thousands of dollars in maintenance costs each year.

  10. Pulse-echo ultrasonic inspection system for in-situ nondestructive inspection of Space Shuttle RCC heat shields.

    SciTech Connect (OSTI)

    Roach, Dennis Patrick; Walkington, Phillip D.; Rackow, Kirk A.

    2005-06-01T23:59:59.000Z

    The reinforced carbon-carbon (RCC) heat shield components on the Space Shuttle's wings must withstand harsh atmospheric reentry environments where the wing leading edge can reach temperatures of 3,000 F. Potential damage includes impact damage, micro cracks, oxidation in the silicon carbide-to-carbon-carbon layers, and interlaminar disbonds. Since accumulated damage in the thick, carbon-carbon and silicon-carbide layers of the heat shields can lead to catastrophic failure of the Shuttle's heat protection system, it was essential for NASA to institute an accurate health monitoring program. NASA's goal was to obtain turnkey inspection systems that could certify the integrity of the Shuttle heat shields prior to each mission. Because of the possibility of damaging the heat shields during removal, the NDI devices must be deployed without removing the leading edge panels from the wing. Recently, NASA selected a multi-method approach for inspecting the wing leading edge which includes eddy current, thermography, and ultrasonics. The complementary superposition of these three inspection techniques produces a rigorous Orbiter certification process that can reliably detect the array of flaws expected in the Shuttle's heat shields. Sandia Labs produced an in-situ ultrasonic inspection method while NASA Langley developed the eddy current and thermographic techniques. An extensive validation process, including blind inspections monitored by NASA officials, demonstrated the ability of these inspection systems to meet the accuracy, sensitivity, and reliability requirements. This report presents the ultrasonic NDI development process and the final hardware configuration. The work included the use of flight hardware and scrap heat shield panels to discover and overcome the obstacles associated with damage detection in the RCC material. Optimum combinations of custom ultrasonic probes and data analyses were merged with the inspection procedures needed to properly survey the heat shield panels. System features were introduced to minimize the potential for human factors errors in identifying and locating the flaws. The in-situ NDI team completed the transfer of this technology to NASA and USA employees so that they can complete 'Return-to-Flight' certification inspections on all Shuttle Orbiters prior to each launch.

  11. ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS

    E-Print Network [OSTI]

    Johnson, Robert E.

    ELECTRONIC SPUTTERING: FROM ATOMIC PHYSICS TO CONTINUUM MECHANICS Ejection of simple and complex molecules from surfaces probes the response of condensed matter to electronic excitations and has and Engineering Physics at the University of Virginia, Charlottesville. Bo Sundqvist holds the Chair in Ion

  12. Photoabsorption by Ions and Atoms

    SciTech Connect (OSTI)

    Manson, Steven T. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303 (United States)

    2004-12-01T23:59:59.000Z

    Recent progress in theoretical and experimental investigations of photoabsorption by atoms and ions is presented. Specifically, examples of near-chaotic behavior in photoionization of positive ions, low-energy manifestations of nondipole effects, high-energy breakdown of the single particle picture and new phenomenology uncovered in the inner-shell photoabsorption by negative ions are discussed.

  13. Realization of a superconducting atom chip

    E-Print Network [OSTI]

    Thomas Nirrengarten; Angie Qarry; Cédric Roux; Andreas Emmert; Gilles Nogues; Michel Brune; Jean-Michel Raimond; Serge Haroche

    2006-10-09T23:59:59.000Z

    We have trapped rubidium atoms in the magnetic field produced by a superconducting atom chip operated at liquid Helium temperatures. Up to $8.2\\cdot 10^5$ atoms are held in a Ioffe-Pritchard trap at a distance of 440 $\\mu$m from the chip surface, with a temperature of 40 $\\mu$K. The trap lifetime reaches 115 s at low atomic densities. These results open the way to the exploration of atom--surface interactions and coherent atomic transport in a superconducting environment, whose properties are radically different from normal metals at room temperature.

  14. Remote atom entanglement in a fiber-connected three-atom system

    E-Print Network [OSTI]

    Guo Yan-Qing; Chen Jing; Song He-Shan

    2008-05-28T23:59:59.000Z

    An Ising-type atom-atom interaction is obtained in a fiber-connected three-atom system. The interaction is effective when $\\Delta\\approx \\gamma _{0}\\gg g$. The preparations of remote two-atom and three-atom entanglement governed by this interaction are discussed in specific parameters region. The overall two-atom entanglement is very small because of the existence of the third atom. However, the three-atom entanglement can reach a maximum very close to 1.

  15. Analysis ofRH TRU Wastes for Containment in Lead Shielded Containers INV-SAR-08, Revision 0 Page I Of~'P~8tJ},f1-

    E-Print Network [OSTI]

    .2 Cellulose, Plastic, Rubber, Steel and Lead Associated with Shielded Container Emplacement 6 4.3 Number of 30-gallon Containers, 3-Packs and Stacks for Shielded Containers 8 4.4 Mass of Plastic, Steel, and LeadAnalysis ofRH TRU Wastes for Containment in Lead Shielded Containers INV-SAR-08, Revision 0 Page I

  16. Role of atomic collisions in fusion

    SciTech Connect (OSTI)

    Post, D.E.

    1982-04-01T23:59:59.000Z

    Atomic physics issues have played a large role in controlled fusion research. A general discussion of the present role of atomic processes in both magnetic and inertial controlled fusion work is presented.

  17. Preliminary steps to the Atomic Energy Commission

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    program to the newly created Atomic Energy Commission. He had succeeded in ending the war, but the transition to peacetime use of atomic energy was not something the Army was...

  18. atomic kitteni lauljatar: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  19. atoms barrasiye barhamkoneshhaye: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory...

  20. atomic mass spectrometry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Negative *) Atomic composition Graham, Nick 3 Prospects in Analytical Atomic Spectrometry CERN Preprints Summary: Tendencies in five main branches of atomic spectrometry...

  1. Institute for Atom-Efficient Chemical Transformations Energy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    adsorbed in a zirconium oxide nanobowl. The brown atoms are surface oxygen and the coral atoms are zirconium. Carbon, oxygen, and hydrogen atoms of fructose molecules are...

  2. Towards a high-precision atomic gyroscope

    E-Print Network [OSTI]

    Van Camp, Mackenzie A. (Mackenzie Anne)

    2013-01-01T23:59:59.000Z

    In this thesis, I report on the design and construction of the Rubidium Atomic Gyroscope Experiment (RAGE) at Draper Lab.

  3. Atomic Ordering Enhanced Electrocatalytic Activity of Nanoalloys...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ordering Enhanced Electrocatalytic Activity of Nanoalloys for Oxygen Reduction Reaction. Atomic Ordering Enhanced Electrocatalytic Activity of Nanoalloys for Oxygen Reduction...

  4. Investigation of an isotopically tailored boron-aluminum alloy's neutronic properties for application in neutron shielding

    E-Print Network [OSTI]

    Schleyer, William Charles

    1989-01-01T23:59:59.000Z

    -infinity as a function of moderation for Alboron (4. 5wt /o boI'on, 95at /o B-1 0). 63 13 K-infinity as a function of half-pitch separation for a 4. 5wt'%%d assembly poisoned with Alboron (4. 5wt'/o or 95% B-1 0) of increasing thickness. . . . . . . . 14 K... Elemental and Composition Densities . 14 93 A. ll Assembly and Structural Material Atomic Concentrations 94 A. lll Neutron Poison Material Atomic Concentrations . 95 B. l Pin Cell NITAWL and XSDRNPM-S Input for 4. 5wt'/o z~U. . . 97 B. ll Pin Cell...

  5. Chaotic Behaviour of Atomic Energy Levels

    E-Print Network [OSTI]

    A. Yilmaz; G. Hacibekiroglu; E. Bolcal; Y. Polatoglu

    2008-04-01T23:59:59.000Z

    The authors of this paper studied Schrodinger wave equation to investiagate the chaotic behavior of atomic energy levels in relation with three quantum numbers n, l, m by means of derived inequality. It could give rise to the siplitting of atomic spectral lines. Keywords: Chaos, Schrodinger wave equation, atomic energy levels

  6. Riso Report No. Danish Atomic Energy Commission

    E-Print Network [OSTI]

    Jagiellonski Institute of Physics Krakow, Poland and P. A. Lindgård Mogensen The Danish Atomic EnergyfM O o 8- OL '·O c/i Riso Report No. Danish Atomic Energy Commission Research Establishment Riso/t on exchangefrom: Library, Danish Atomic Energy Commission, Risd, Roskilde, Denmark #12;May, 1966 Ris6 Report No

  7. Driven Ratchets for Cold Atoms

    E-Print Network [OSTI]

    Renzoni, F

    2011-01-01T23:59:59.000Z

    Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations. The ratchet effect is a very general phenomenon which applies to a wide range of physical systems, and indeed ratchets have been realized with a variety of solid state devices, with optical trap setups as well as with synthetic molecules and granular gases. The present article reviews recent experimental realizations of ac driven ratchets with cold atoms in driven optical lattices. This is quite an unusual system for a Brownian motor as there is no a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields. Such a system allowed us to realize experimentally rocking and gating ratchets, and to precisely investigate the relationship between symmetry and transport in these ratchets, both for the case of periodic and quasiperiodic driving.

  8. Driven Ratchets for Cold Atoms

    E-Print Network [OSTI]

    F. Renzoni

    2011-12-05T23:59:59.000Z

    Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations. The ratchet effect is a very general phenomenon which applies to a wide range of physical systems, and indeed ratchets have been realized with a variety of solid state devices, with optical trap setups as well as with synthetic molecules and granular gases. The present article reviews recent experimental realizations of ac driven ratchets with cold atoms in driven optical lattices. This is quite an unusual system for a Brownian motor as there is no a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields. Such a system allowed us to realize experimentally rocking and gating ratchets, and to precisely investigate the relationship between symmetry and transport in these ratchets, both for the case of periodic and quasiperiodic driving.

  9. The Future of Atomic Energy

    DOE R&D Accomplishments [OSTI]

    Fermi, E.

    1946-05-27T23:59:59.000Z

    There is definitely a technical possibility that atomic power may gradually develop into one of the principal sources of useful power. If this expectation will prove correct, great advantages can be expected to come from the fact that the weight of the fuel is almost negligible. This feature may be particularly valuable for making power available to regions of difficult access and far from deposits of coal. It also may prove a great asset in mobile power units for example in a power plant for ship propulsion. On the negative side there are some technical limitations to be applicability of atomic power of which perhaps the most serious is the impossibility of constructing light power units; also there will be some peculiar difficulties in operating atomic plants, as for example the necessity of handling highly radioactive substances which will necessitate, at least for some considerable period, the use of specially skilled personnel for the operation. But the chief obstacle in the way of developing atomic power will be the difficulty of organizing a large scale industrial development in an internationally safe way. This presents actually problems much more difficult to solve than any of the technical developments that are necessary, It will require an unusual amount of statesmanship to balance properly the necessity of allaying the international suspicion that arises from withholding technical secrets against the obvious danger of dumping the details of the procedures for an extremely dangerous new method of warfare on a world that may not yet be prepared to renounce war. Furthermore, the proper balance should be found in the relatively short time that will elapse before the 'secrets' will naturally become open knowledge by rediscovery on part of the scientists and engineers of other countries.

  10. Asymmetric dose–volume optimization with smoothness control for rotating-shield brachytherapy

    SciTech Connect (OSTI)

    Liu, Yunlong [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 (United States); Flynn, Ryan T.; Kim, Yusung [Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Wu, Xiaodong, E-mail: xiaodong-wu@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, 4016 Seamans Center, Iowa City, Iowa 52242 and Department of Radiation Oncology, University of Iowa, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: It is important to reduce fluence map complexity in rotating-shield brachytherapy (RSBT) inverse planning to improve delivery efficiency while maintaining plan quality. This study proposes an efficient and effective RSBT dose optimization method which enables to produce smooth fluence maps. Methods: Five cervical cancer patients each with a high-risk clinical-target-volume (HR-CTV) larger than 40 cm{sup 3} were considered as the test cases. The RSBT source was a partially shielded electronic brachytherapy source (Xoft Axxent™). The anchor RSBT plans generated by the asymmetric dose–volume optimization with smoothness control (ADOS) method were compared against those produced by the dose–surface optimization (DSO) method and inverse-planning with simulated annealing (IPSA). Either L{sub 1}-norm or L{sub 2}-norm was used to measure the smoothness of a fluence map in the proposed ADOS method as one weighted term of the objective function. Uniform dwell-time scaling was applied to all plans such that HR-CTV D{sub 90} was maximized without violating the D{sub 2cc} tolerances of the rectum, bladder, and sigmoid colon. The quality of the anchor plans was measured with HR-CTV D{sub 90} of the anchor plans. Single-shielded RSBT [(S-RSBT), RSBT with single, fix sized delivery window] and dynamic-sheilded RSBT [(D-RSBT), RSBT with dynamically varying sized delivery window] delivery plans generated based on the anchor plans were also measured, with delivery time constraints of 10, 20, and 30 min/fraction (fx). Results: The average HR-CTV D{sub 90} values of the anchor plans achieved by the ADOS, DSO, and IPSA methods were 111.5, 94.2, and 107.4 Gy, respectively, where the weighting parameter ? used in ADOS with L{sub 2}-norm was set to be 100. By using S-RSBT sequencing and 20 min/fx delivery time, the corresponding D{sub 90} values were 88.8, 81.9, and 83.4 Gy; while using D-RSBT sequencing with 20 min/fx delivery time, the corresponding D{sub 90} values were 91.4, 88.3, and 78.9 Gy, respectively. The average optimization times for ADOS, DSO, and IPSA were, respectively, 77, 4, and 1800 s. By using L{sub 1}-norm instead of L{sub 2}-norm in the ADOS method, the optimization time was increased by 20 s, while the D{sub 90} was reduced by 6.8 Gy on average. ADOS-L1 was found to be more sensitive to the weighting parameter than ADOS-L2. If ? was increased to 10?000, the D{sub 90} drop with ADOS-L1 was 38 Gy, while the drop with ADOS-L2 is 13 Gy. Conclusions: The ADOS method had a reasonable optimization time cost, while achieving comparable RSBT dose plans as the IPSA method, which is of much higher time complexity. Compared to the DSO and IPSA methods, ADOS is able to generate anchor plans which are more suitable for RSBT delivery while preserving the high quality of the original plans. Compared to ADOS-L1, ADOS-L2 is able to achieve better quality of anchor plans more efficiently.

  11. Gauge invariant hydrogen atom Hamiltonian

    E-Print Network [OSTI]

    Wei-Min Sun; Xiang-Song Chen; Xiao-Fu Lu; Fan Wang

    2010-06-22T23:59:59.000Z

    For quantum mechanics of a charged particle in a classical external electromagnetic field, there is an apparent puzzle that the matrix element of the canonical momentum and Hamiltonian operators is gauge dependent. A resolution to this puzzle is recently provided by us in [2]. Based on the separation of the electromagnetic potential into pure gauge and gauge invariant parts, we have proposed a new set of momentum and Hamiltonian operators which satisfy both the requirement of gauge invariance and the relevant commutation relations. In this paper we report a check for the case of the hydrogen atom problem: Starting from the Hamiltonian of the coupled electron, proton and electromagnetic field, under the infinite proton mass approximation, we derive the gauge invariant hydrogen atom Hamiltonian and verify explicitly that this Hamiltonian is different from the Dirac Hamiltonian, which is the time translation generator of the system. The gauge invariant Hamiltonian is the energy operator, whose eigenvalue is the energy of the hydrogen atom. It is generally time-dependent. In this case, one can solve the energy eigenvalue equation at any specific instant of time. It is shown that the energy eigenvalues are gauge independent, and by suitably choosing the phase factor of the time-dependent eigenfunction, one can ensure that the time-dependent eigenfunction satisfies the Dirac equation.

  12. NAAP Hydrogen Atom 1/9 The Hydrogen Atom Student Guide

    E-Print Network [OSTI]

    Farritor, Shane

    Name: NAAP ­ Hydrogen Atom 1/9 The Hydrogen Atom ­ Student Guide Background Material Carefully read and the Quantum model represent the Hydrogen atom. In some cases they both describe things in the same way frequency, smaller energy, and the same velocity through space as a blue photon". #12;NAAP ­Hydrogen Atom 2

  13. Fast transport, atom sample splitting and single-atom qubit supply in two-dimensional arrays

    E-Print Network [OSTI]

    Birkl, Gerhard

    Fast transport, atom sample splitting and single-atom qubit supply in two-dimensional arrays architecture for neutral atom quantum information processing, quantum simulation and the manipulation of ultra-cold implemented functions. We introduce piezo-actuator-based transport of atom ensembles over distances of more

  14. Precision Measurement of the Newtonian Gravitational Constant Using Cold Atoms

    E-Print Network [OSTI]

    G. Rosi; F. Sorrentino; L. Cacciapuoti; M. Prevedelli; G. M. Tino

    2014-12-26T23:59:59.000Z

    About 300 experiments have tried to determine the value of the Newtonian gravitational constant, G, so far, but large discrepancies in the results have made it impossible to know its value precisely. The weakness of the gravitational interaction and the impossibility of shielding the effects of gravity make it very difficult to measure G while keeping systematic effects under control. Most previous experiments performed were based on the torsion pendulum or torsion balance scheme as in the experiment by Cavendish in 1798, and in all cases macroscopic masses were used. Here we report the precise determination of G using laser-cooled atoms and quantum interferometry. We obtain the value G=6.67191(99) x 10^(-11) m^3 kg^(-1) s^(-2) with a relative uncertainty of 150 parts per million (the combined standard uncertainty is given in parentheses). Our value differs by 1.5 combined standard deviations from the current recommended value of the Committee on Data for Science and Technology. A conceptually different experiment such as ours helps to identify the systematic errors that have proved elusive in previous experiments, thus improving the confidence in the value of G. There is no definitive relationship between G and the other fundamental constants, and there is no theoretical prediction for its value, against which to test experimental results. Improving the precision with which we know G has not only a pure metrological interest, but is also important because of the key role that G has in theories of gravitation, cosmology, particle physics and astrophysics and in geophysical models.

  15. Ultracold Atoms: How Quantum Field Theory Invaded Atomic Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin TransitionProgram |Frank CasellaEnergyUltracold Atoms: How Quantum

  16. Engineering Atomic Quantum Reservoirs for Photons

    E-Print Network [OSTI]

    Susanne Pielawa; Luiz Davidovich; David Vitali; Giovanna Morigi

    2010-04-06T23:59:59.000Z

    We present protocols for creating entangled states of two modes of the electromagnetic field, by using a beam of atoms crossing microwave resonators. The atoms are driven by a transverse, classical field and pump correlated photons into (i) two modes of a cavity and (ii) the modes of two distant cavities. The protocols are based on a stochastic dynamics, characterized by random arrival times of the atoms and by random interaction times between atoms and cavity modes. The resulting effective model yields a master equation, whose steady state is an entangled state of the cavity modes. In this respect, the atoms act like a quantum reservoir, pulling the cavity modes into an entangled, Einstein-Podolski-Rosen (EPR) state, whose degree of entanglement is controlled by the intensity and the frequency of the transverse field. This scheme is robust against stochastic fluctuations in the atomic beam, and it does not require atomic detection nor velocity selection.

  17. Engineering Atomic Quantum Reservoirs for Photons

    E-Print Network [OSTI]

    Pielawa, Susanne; Vitali, David; Morigi, Giovanna

    2010-01-01T23:59:59.000Z

    We present protocols for creating entangled states of two modes of the electromagnetic field, by using a beam of atoms crossing microwave resonators. The atoms are driven by a transverse, classical field and pump correlated photons into (i) two modes of a cavity and (ii) the modes of two distant cavities. The protocols are based on a stochastic dynamics, characterized by random arrival times of the atoms and by random interaction times between atoms and cavity modes. The resulting effective model yields a master equation, whose steady state is an entangled state of the cavity modes. In this respect, the atoms act like a quantum reservoir, pulling the cavity modes into an entangled, Einstein-Podolski-Rosen (EPR) state, whose degree of entanglement is controlled by the intensity and the frequency of the transverse field. This scheme is robust against stochastic fluctuations in the atomic beam, and it does not require atomic detection nor velocity selection.

  18. atomic recoil laser: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Recoil Laser Quantum Physics (arXiv) Summary: We formulate a wave atom optics theory of the Collective Atomic Recoil Laser, where the atomic center-of-mass motion...

  19. Dynamics of Tilt-based Browsing on Mobile Devices

    E-Print Network [OSTI]

    Cho, S.J.; Murray-Smith, R.

    Cho,S.J. Murray-Smith,R. Choi,C. Sung,Y. Lee,K. Kim,Y.B. CHI '07 extended abstracts on Human factors in computing systems, http://doi.acm.org/10.1145/1240866.1240930 pp 1947 - 1952 ACM Press

  20. Processes, Techniques, and Successes in Welding the Dry Shielded Canisters of the TMI-2 Reactor Core Debris

    SciTech Connect (OSTI)

    Zirker, L.R.; Rankin, R.A.; Ferrell, L.J.

    2002-01-29T23:59:59.000Z

    The Idaho National Engineering and Environmental Laboratory (INEEL) is operated by Bechtel-BWXT Idaho LLC (BBWI), which recently completed a very successful $100 million Three-Mile Island-2 (TMI-2) program for the Department of Energy (DOE). This complex and challenging program used an integrated multidisciplinary team approach that loaded, welded, and transported an unprecedented 25 dry shielded canisters (DSC) in seven months, and did so ahead of schedule. The program moved over 340 canisters of TMI-2 core debris that had been in wet storage into a dry storage facility at the INEEL. The main thrust of this paper is relating the innovations, techniques, approaches, and lessons learned associated to welding of the DSC's. This paper shows the synergism of elements to meet program success and shares these lessons learned that will facilitate success with welding of dry shielded canisters in other DOE complex dry storage programs.

  1. Material Open Test Assembly Specimen Retrieval from Hanford's Shielded Material Facility

    SciTech Connect (OSTI)

    Valdez, Patrick LJ; Rinker, Michael W.

    2009-06-14T23:59:59.000Z

    Hanford’s 324 Building, the Shielded Material Facility (SMF), was developed to provide containment for research and fabrication development studies on highly radioactive metallic and ceramic nuclear reactor fuels and structural materials. Between 1983 and 1992, the SMF was used in support of the Department of Energy (DOE)-funded Fast Flux Test Facility (FFTF) Materials Open Test Assembly (MOTA) program. In this program, metallurgical specimens were irradiated in FFTF and then sent to SMF for processing and storage in two cabinets. This effort was abruptly ended in early 1990s due to programmatic shifts within the DOE, leaving many specimens unexamined. In recent years, these specimens have become of high value to new DOE programs. Pacific Northwest National Laboratory (PNNL) was tasked with retrieving specimens from one of the cabinets in support of fuel clad and duct development for the Advanced Fuel Cycle Initiative. Cesium contamination of the cell and failure of the overhead crane system utilized for opening the cabinets prevented PNNL from using the built-in hot cell equipment to gain access to the cabinets. PNNL designed and tested a lifting device to fit through a standard 10 inch diameter mechanical manipulator port in the SMF South Cell wall. The tool was successfully deployed in June 2008 with the support of Washington Closure Hanford.

  2. Concrete Shield Performance of the VSC-17 Spent Nuclear Fuel Cask

    SciTech Connect (OSTI)

    Sheryl L. Morton; Philip L. Winston; Toshiari Saegusa; Koji Shirai; Akihiro Sasahara; Takatoshi Hattori

    2006-04-01T23:59:59.000Z

    In 2003, representatives from the Central Research Institute of Electric Power Industry (CRIEPI) requested development of a project with the objective of determining the performance of a concrete spent nuclear fuel storage cask. Radiation and environmental effects may cause chemical alteration of the concrete that could result in excessive cracking, spalling, and loss of compressive strength. The Idaho National Laboratory (INL) project team and CRIEPI representatives identified the Ventilated Storage Cask (VSC-17) spent nuclear fuel storage cask as a candidate to study cask performance, because it had been used to store fuel as part of a dry cask storage demonstration project for more than 15 years. The project involved investigating the properties of the concrete shield. INL performed a survey of the cask in the summers of 2003 and 2004. Preliminary cask evaluations performed in 2003 indicated that the cask has no visual degradation. However, a 4-5 mrem/hr step-change in the radiation levels about halfway up the cask and a localized hot spot beneath an upper air vent indicate that there may be variability in the density of the concrete or localized cracking. In 2005, INL and CRIEPI scientists performed additional surveys on the VSC-17 cask. This document summarizes the methods used on the VSC-17 to evaluate the cask for compressive strength, concrete cracking, concrete thickness, and temperature distribution.

  3. The new solid target system at UNAM in a self-shielded 11 MeV cyclotron

    SciTech Connect (OSTI)

    Zarate-Morales, A.; Gaspar-Carcamo, R. E.; Lopez-Rodriguez, V.; Flores-Moreno, A.; Trejo-Ballado, F.; Avila-Rodriguez, Miguel A. [Unidad PET, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, 04510 , D.F. Mexico (Mexico)

    2012-12-19T23:59:59.000Z

    A dual beam line (BL) self-shielded RDS 111 cyclotron for radionuclide production was installed at the School of Medicine of the National Autonomous University of Mexico in 2001. One of the BL's was upgraded to Eclipse HP (Siemens) in 2008 and the second BL was recently upgraded (June 2011) to the same version with the option for the irradiation of solid targets for the production of metallic radioisotopes.

  4. Density functional investigation of intermolecular effects on {sup 13}C NMR chemical-shielding tensors modeled with molecular clusters

    SciTech Connect (OSTI)

    Holmes, Sean T.; Dybowski, Cecil [Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716 (United States); Iuliucci, Robbie J. [Department of Chemistry, Washington and Jefferson College, Washington, Pennsylvania 15301 (United States); Mueller, Karl T. [Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

    2014-10-28T23:59:59.000Z

    A quantum-chemical method for modeling solid-state nuclear magnetic resonance chemical-shift tensors by calculations on large symmetry-adapted clusters of molecules is demonstrated. Four hundred sixty five principal components of the {sup 13}C chemical-shielding tensors of 24 organic materials are analyzed. The comparison of calculations on isolated molecules with molecules in clusters demonstrates that intermolecular effects can be successfully modeled using a cluster that represents a local portion of the lattice structure, without the need to use periodic-boundary conditions (PBCs). The accuracy of calculations which model the solid state using a cluster rivals the accuracy of calculations which model the solid state using PBCs, provided the cluster preserves the symmetry properties of the crystalline space group. The size and symmetry conditions that the model cluster must satisfy to obtain significant agreement with experimental chemical-shift values are discussed. The symmetry constraints described in the paper provide a systematic approach for incorporating intermolecular effects into chemical-shielding calculations performed at a level of theory that is more advanced than the generalized gradient approximation. Specifically, NMR parameters are calculated using the hybrid exchange-correlation functional B3PW91, which is not available in periodic codes. Calculations on structures of four molecules refined with density plane waves yield chemical-shielding values that are essentially in agreement with calculations on clusters where only the hydrogen sites are optimized and are used to provide insight into the inherent sensitivity of chemical shielding to lattice structure, including the role of rovibrational effects.

  5. Atomic Structure Calculations from the Los Alamos Atomic Physics Codes

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Cowan, R. D.

    The well known Hartree-Fock method of R.D. Cowan, developed at Los Alamos National Laboratory, is used for the atomic structure calculations. Electron impact excitation cross sections are calculated using either the distorted wave approximation (DWA) or the first order many body theory (FOMBT). Electron impact ionization cross sections can be calculated using the scaled hydrogenic method developed by Sampson and co-workers, the binary encounter method or the distorted wave method. Photoionization cross sections and, where appropriate, autoionizations are also calculated. Original manuals for the atomic structure code, the collisional excitation code, and the ionization code, are available from this website. Using the specialized interface, you will be able to define the ionization stage of an element and pick the initial and final configurations. You will be led through a series of web pages ending with a display of results in the form of cross sections, collision strengths or rates coefficients. Results are available in tabular and graphic form.

  6. Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields

    E-Print Network [OSTI]

    Seoung, Youl-Hun

    2015-01-01T23:59:59.000Z

    The purpose of the present study was to evaluate radiation dose reduction and image quality during CT scanning by using a new dose reduction fiber sheet (DRFS) with commercially available bismuth shields. These DRFS were composed of nano-barium sulfate (BaSO4), filling the gaps left by the large oxide bismuth (Bi2O3) particle sizes. The radiation dose was measured five times at directionss of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom to calculate an average value using a CT ionization chamber. The image quality measured CT transverse images of the PMMA head phantom depending on X-ray tube voltages and the type of shielding. Two regions of interest in CT transverse images were chosen from the right and left areas under the surface of the PMMA head phantom and from ion chamber holes located at directions of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce dosages to 15.61%, 23.05%, and 22.71% more in ...

  7. General Atomics | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdf Jump1946865°,Park, Texas:Webinars/Puesta en Marcha,Geary,GenSelfandAtomics

  8. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED MELDING PROCESSES IN RELATION TO THE ARC CURRENT DENSITY A Thesis by ROBIN KENT DEVORE Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT...

  9. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density 

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT... DENSITY A Thesis by ROBIN KENT DEVORE Approved as to style and content by: C alarm n of o itte Hea o partment e er Member December 1973 ABSTRACT The Effective Spectral Irradiance of Ultraviolet Radiations from Inert-Gas-Shielded Welding...

  10. Atoms can be divided into three categories: polar, non-polar and hydrogen atom

    E-Print Network [OSTI]

    Pei-Lin You

    2010-10-10T23:59:59.000Z

    Since the time of Rutherford 1911) physicists and chemists commonly believed that with no electric field, the nucleus of an atom is at the centre of the electron cloud, atoms do not have permanent electric dipole moment (EDM), so that there is no polar atom in nature. In the fact, the idea is untested hypothesis. After ten years of intense research, our experiments showed that atoms can be divided into three categories: polar, non-polar and hydrogen atom. Alkali atoms are all polar atoms. The EDM of a Sodium, Potassium, Rubidium and Cesium atom in the ground state have been obtained as follows: d(Na)=1.28*10 to-8 power e.cm; d(K)=1.58*10 to-8 power e.cm; d(Rb)=1.70 *10 to-8 power e.cm; d(Cs)=1.86*10 to-8 power e.cm. All kind of atoms are non-polar atoms except for alkali and hydrogen atoms. Hydrogen atom is quite distinct from the others. The ground state in hydrogen is non-polar atom(d=0) but the excited state is polar atom, for example, the first excited state has a large EDM: d(H)=3ea=1.59*10 to-8 power e.cm (a is Bohr radius).

  11. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V. C.; Wang, Chengpu

    2006-08-22T23:59:59.000Z

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  12. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V.; Wang, Chengpu

    2004-11-16T23:59:59.000Z

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  13. Sensing mode atomic force microscope

    DOE Patents [OSTI]

    Hough, Paul V. C. (Port Jefferson, NY); Wang, Chengpu (Upton, NY)

    2003-01-01T23:59:59.000Z

    An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

  14. Hydrogen Atom in Relativistic Motion

    E-Print Network [OSTI]

    M. Jarvinen

    2005-04-11T23:59:59.000Z

    The Lorentz contraction of bound states in field theory is often appealed to in qualitative descriptions of high energy particle collisions. Surprisingly, the contraction has not been demonstrated explicitly even in simple cases such as the hydrogen atom. It requires a calculation of wave functions evaluated at equal (ordinary) time for bound states in motion. Such wave functions are not obtained by kinematic boosts from the rest frame. Starting from the exact Bethe-Salpeter equation we derive the equal-time wave function of a fermion-antifermion bound state in QED, i.e., positronium or the hydrogen atom, in any frame to leading order in alpha. We show explicitly that the bound state energy transforms as the fourth component of a vector and that the wave function of the fermion-antifermion Fock state contracts as expected. Transverse photon exchange contributes at leading order to the binding energy of the bound state in motion. We study the general features of the corresponding fermion-antifermion-photon Fock states, and show that they do not transform by simply contracting. We verify that the wave function reduces to the light-front one in the infinite momentum frame.

  15. Calculation of shielding door thicknesses for radiation therapy facilities using the ITS Monte Carlo program

    SciTech Connect (OSTI)

    Biggs, P.J. (Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston (United States))

    1991-10-01T23:59:59.000Z

    Shielding calculations for door thicknesses for megavoltage radiotherapy facilities with mazes are generally straightforward. To simplify the calculations, the standard formalism adopts several approximations relating to the average beam path, scattering coefficients, and the mean energy of the spectrum of scattered radiation. To test the accuracy of these calculations, the Monte Carlo program, ITS, was applied to this problem by determining the dose and energy spectrum of the radiation at the door for 4- and 10-MV bremsstrahlung beams incident on a phantom at isocenter. This was performed for mazes, one termed 'standard' and the other a shorter maze where the primary beam is incident on the wall adjacent to the door. The peak of the photon-energy spectrum at the door was found to be the same for both types of maze, independent of primary beam energy, and also, in the case of the conventional maze, of the primary beam orientation. The spectrum was harder for the short maze and for 10 MV vs. 4 MV. The thickness of the lead door for a short maze configuration was 1.5 cm for 10 MV and 1.2 cm for 4 MV vs. approximately less than 1 mm for a conventional maze. For the conventional maze, the Monte Carlo calculation predicts the dose at the door to be lower than given by NCRP 49 and NCRP 51 by about a factor of 2 at 4 MV but to be the same at 10 MV. For the short maze, the Monte Carlo predicts the dose to be a factor of 3 lower for 4 MV and about a factor of 1.5 lower for 10 MV. Experimental results support the Monte Carlo findings for the short maze.

  16. Phases of Atom-Molecule Vortex Matter

    SciTech Connect (OSTI)

    Woo, S. J.; Bigelow, N. P. [Department of Physics and Astronomy, University of Rochester, Rochester, New York (United States); Park, Q-Han [Department of Physics, Korea University, Seoul (Korea, Republic of)

    2008-03-28T23:59:59.000Z

    We study ground state vortex configurations in a rotating atom-molecule Bose-Einstein condensate. It is found that the coherent coupling between the atomic and molecular condensates can render a pairing of atomic and molecular vortices into a composite structure that resembles a carbon dioxide molecule. Structural phase transitions of vortex lattices are also explored through different physical parameters including the rotational frequency of the system.

  17. Method for enhanced atomization of liquids

    DOE Patents [OSTI]

    Thompson, Richard E. (27121 Puerta del Oro, Mission Viejo, CA 92691); White, Jerome R. (44755 Wyandotte, Hemet, CA 92544)

    1993-01-01T23:59:59.000Z

    In a process for atomizing a slurry or liquid process stream in which a slurry or liquid is passed through a nozzle to provide a primary atomized process stream, an improvement which comprises subjecting the liquid or slurry process stream to microwave energy as the liquid or slurry process stream exits the nozzle, wherein sufficient microwave heating is provided to flash vaporize the primary atomized process stream.

  18. CERTIFICATION DOCKET WESTINGHOUSE ATOMIC POWER DEVELOPMENT PLANT

    Office of Legacy Management (LM)

    Westinghouse Atomic 1 U.S. Department of Energy Interim Residual Contamination and Waste Control Guidelines for bormerly Utilized Sites Remedial Action Program (FUSRAP) d Remote...

  19. Atomic 'mismatch' creates nano 'dumbbells' | Argonne National...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic 'mismatch' creates nano 'dumbbells' By Jared Sagoff * December 4, 2014 Tweet EmailPrint ARGONNE, Ill. - Like snowflakes, nanoparticles come in a wide variety of shapes and...

  20. Atomic Energy and Nuclear Materials Program (Tennessee)

    Broader source: Energy.gov [DOE]

    The Atomic Energy and Nuclear Materials section of the Tennessee Code covers all of the regulations, licenses, permits, siting requirements, and practices relevant to a nuclear energy development. ...

  1. Classical and Quantum Chaos in Atom Optics

    E-Print Network [OSTI]

    Farhan Saif

    2006-04-10T23:59:59.000Z

    The interaction of an atom with an electromagnetic field is discussed in the presence of a time periodic external modulating force. It is explained that a control on atom by electromagnetic fields helps to design the quantum analog of classical optical systems. In these atom optical systems chaos may appear at the onset of external fields. The classical and quantum chaotic dynamics is discussed, in particular in an atom optics Fermi accelerator. It is found that the quantum dynamics exhibits dynamical localization and quantum recurrences.

  2. United States Atomic Energy Commission formed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    weapons problem, the United States worked to establish its own formal organization. The transition from military civilian control of nuclear energy was defined in the Atomic...

  3. Distribution Category: Atomic, Molecular, and Chemical Physics

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic, Molecular, and Chemical Physics (UC-411) ARGONNE NATIONAL LABORATORY 9700 South Cass Avenue Argonne, TIlinois 60439 ANLI APSILS-151 RESULTS OF DESIGN CALCULATIONS FOR THE...

  4. Remote preparation of an atomic quantum memory

    E-Print Network [OSTI]

    Wenjamin Rosenfeld; Stefan Berner; Juergen Volz; Markus Weber; Harald Weinfurter

    2006-08-29T23:59:59.000Z

    Storage and distribution of quantum information are key elements of quantum information processing and quantum communication. Here, using atom-photon entanglement as the main physical resource, we experimentally demonstrate the preparation of a distant atomic quantum memory. Applying a quantum teleportation protocol on a locally prepared state of a photonic qubit, we realized this so-called remote state preparation on a single, optically trapped 87Rb atom. We evaluated the performance of this scheme by the full tomography of the prepared atomic state, reaching an average fidelity of 82%.

  5. Gas Atomization of Stainless Steel - Slow Motion

    SciTech Connect (OSTI)

    None

    2011-01-01T23:59:59.000Z

    Stainless steel liquid atomized by supersonic argon gas into a spray of droplets at ~1800ºC. Atomization of metal requires high pressure gas and specialized chambers for cooling and collecting the powders without contamination. The critical step for morphological control is the impingement of the gas on the melt stream. The video is a black and white high speed video of a liquid metal stream being atomized by high pressure gas. This material was atomized at the Ames Laboratory's Materials Preparation Center http://www.mpc.ameslab.gov

  6. Subwavelength Transportation of Light with Atomic Resonances

    E-Print Network [OSTI]

    Chui, Siu-Tat; Jo, Gyu-Boong

    2015-01-01T23:59:59.000Z

    We propose and investigate a new type of optical waveguide made by an array of atoms without involving conventional Bragg scattering or total internal reflection. A finite chain of atoms collectively coupled through their intrinsic resonance supports a propagating mode with minimal radiative loss when the array spacing $a$ is around 0.6$\\lambda_0/2\\pi$ where $\\lambda_0$ is the wavelength of the nearly resonant optical transition. We find that the transportation is robust with respect to position fluctuation and remains possible when the atoms are placed on a circle. Our result paves the way to implement the subwavelength transportation of light in integrated optical circuits with cold atoms.

  7. CARBON ATOM DISTRIBUTION IN A DUAL PHASE STEEL: AN ATOM PROBE STUDY

    E-Print Network [OSTI]

    Barnard, S.J.

    2014-01-01T23:59:59.000Z

    ATOM DISTRIBUTION IN A DUAL PHASE STEEL: AN ATOM PROBE STUDY~4720 1 U.S.A. IntroductioE. Dual Phase steels are currentlymartensite-austenite dual phase steel, although the results

  8. Vibrational Modes of Adsorbed Atoms

    E-Print Network [OSTI]

    LAWRENCE, WR; Allen, Roland E.

    1977-01-01T23:59:59.000Z

    of adsorbed atoms. vi rational modes *Present address: S h University of H c ool of Scienc City, Tex. ouston at Clear La ', r e e and Technology Lake City, Clea Lak %. R. wrence and R. E. Allen published). Allen, Phys. Rev. B (to be 2G. P... are about t r Ne on Kr. The d ou he same as fo mode labeled 2V a as large in the f' t X is almost erst (adsorbate) la e od( b t t)l pure surface mod e ayer. The 1H mode at X is a 4, this mode bec m e. Just to the r'right of X in Fig. e ecomes a...

  9. Relativistic atomic physics at the SSC

    SciTech Connect (OSTI)

    NONE

    1990-12-31T23:59:59.000Z

    This report discusses the following proposed work for relativistic atomic physics at the Superconducting Super Collider: Beam diagnostics; atomic physics research; staffing; education; budget information; statement concerning matching funds; description and justification of major items of equipment; statement of current and pending support; and assurance of compliance.

  10. Atomic processes in high-density plasmas

    SciTech Connect (OSTI)

    More, R.M.

    1982-12-21T23:59:59.000Z

    This review covers dense atomic plasmas such as that produced in inertial confinement fusion. The target implosion physics along with the associated atomic physics, i.e., free electron collision phenomena, electron states I, electron states II, and nonequilibrium plasma states are described. (MOW)

  11. Interaction of trapped ions with trapped atoms

    E-Print Network [OSTI]

    Grier, Andrew T. (Andrew Todd)

    2011-01-01T23:59:59.000Z

    In this thesis, I present results from two Paul-trap based ion traps carried out in the Vuleti? laboratory: the Atom-Ion trap for collision studies between cold atoms and cold ions, and the Cavity-Array trap for studying ...

  12. Photoassociative molecular spectroscopy for atomic radiative lifetimes.

    E-Print Network [OSTI]

    Boyer, Edmond

    very far apart, in so-called long- range molecular states, their mutual interaction is ruled by plain atomic properties. The high- resolution spectroscopic study of some molecular excited states populated by photoassociation of cold atoms (photoassociative spectroscopy) gives a good illustration of this property

  13. Small field segments surrounded by large areas only shielded by a multileaf collimator: Comparison of experiments and dose calculation

    SciTech Connect (OSTI)

    Kron, T.; Clivio, A.; Vanetti, E.; Nicolini, G.; Cramb, J.; Lonski, P.; Cozzi, L.; Fogliata, A. [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne 8006, Australia and Department of Applied Sciences, RMIT University, Melbourne 3001 (Australia); Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona 6500 (Switzerland); Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne 8006 (Australia); Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne 8006, Australia and Department of Applied Sciences, RMIT University, Melbourne 3001 (Australia); Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona 6500 (Switzerland)

    2012-12-15T23:59:59.000Z

    Purpose: Complex radiotherapy fields delivered using a tertiary multileaf collimator (MLC) often feature small open segments surrounded by large areas of the beam only shielded by the MLC. The aim of this study was to test the ability of two modern dose calculation algorithms to accurately calculate the dose in these fields which would be common, for example, in volumetric modulated arc treatment (VMAT) and study the impact of variations in dosimetric leaf gap (DLG), focal spot size, and MLC transmission in the beam models. Methods: Nine test fields with small fields (0.6-3 cm side length) surrounded by large MLC shielded areas (secondary collimator 12 Multiplication-Sign 12 cm{sup 2}) were created using a 6 MV beam from a Varian Clinac iX linear accelerator with 120 leaf MLC. Measurements of output factors and profiles were performed using a diamond detector (PTW) and compared to two dose calculations algorithms anisotropic analytical algorithm [(AAA) and Acuros XB] implemented on a commercial radiotherapy treatment planning system (Varian Eclipse 10). Results: Both calculation algorithms predicted output factors within 1% for field sizes larger than 1 Multiplication-Sign 1 cm{sup 2}. For smaller fields AAA tended to underestimate the dose. Profiles were predicted well for all fields except for problems of Acuros XB to model the secondary penumbra between MLC shielded fields and the secondary collimator. A focal spot size of 1 mm or less, DLG 1.4 mm and MLC transmission of 1.4% provided a generally good model for our experimental setup. Conclusions: AAA and Acuros XB were found to predict the dose under small MLC defined field segments well. While DLG and focal spot affect mostly the penumbra, the choice of correct MLC transmission will be essential to model treatments such as VMAT accurately.

  14. Alternatives evaluation and decommissioning study on shielded transfer tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect (OSTI)

    DeVore, J.R.; Hinton, R.R.

    1994-08-01T23:59:59.000Z

    The shielded transfer tanks (STTs) are five obsolete cylindrical shipping casks which were used to transport high specific activity radioactive solutions by rail during the 1960s and early 1970s. The STTs are currently stored at the Oak Ridge National Laboratory under a shed roof. This report is an evaluation to determine the preferred alternative for the final disposition of the five STTs. The decommissioning alternatives assessed include: (1) the no action alternative to leave the STTs in their present location with continued surveillance and maintenance; (2) solidification of contents within the tanks and holding the STTs in long term retrievable storage; (3) sale of one or more of the used STTs to private industry for use at their treatment facility with the remaining STTs processed as in Alternative 4; and (4) removal of tank contents for de-watering/retrievable storage, limited decontamination to meet acceptance criteria, smelting the STTs to recycle the metal through the DOE contaminated scrap metal program, and returning the shielding lead to the ORNL lead recovery program because the smelting contractor cannot reprocess the lead. To completely evaluate the alternatives for the disposition of the STTs, the contents of the tanks must be characterized. Shielding and handling requirements, risk considerations, and waste acceptance criteria all require that the radioactive inventory and free liquids residual in the STTs be known. Because characterization of the STT contents in the field was not input into a computer model to predict the probable inventory and amount of free liquid. The four alternatives considered were subjected to a numerical scoring procedure. Alternative 4, smelting the STTs to recycle the metal after removal/de-watering of the tank contents, had the highest score and is, therefore, recommended as the preferred alternative. However, if a buyer for one or more STT could be found, it is recommended that Alternative 3 be reconsidered.

  15. Sagnac interferometry with a single atomic clock

    E-Print Network [OSTI]

    Stevenson, R; Bishop, T; Lesanovsky, I; Fernholz, T

    2015-01-01T23:59:59.000Z

    We theoretically discuss an implementation of a Sagnac interferometer with cold atoms. In contrast to currently existing schemes our protocol does not rely on any free propagation of atoms. Instead it is based on superpositions of fully confined atoms and state-dependent transport along a closed path. Using Ramsey sequences for an atomic clock, the accumulated Sagnac phase is encoded in the resulting population imbalance between two internal (clock) states. Using minimal models for the above protocol we analytically quantify limitations arising from atomic dynamics and finite temperature. We discuss an actual implementation of the interferometer with adiabatic radio-frequency potentials that is inherently robust against common mode noise as well as phase noise from the reference oscillator.

  16. Sagnac interferometry with a single atomic clock

    E-Print Network [OSTI]

    R. Stevenson; M. Hush; T. Bishop; I. Lesanovsky; T. Fernholz

    2015-04-21T23:59:59.000Z

    We theoretically discuss an implementation of a Sagnac interferometer with cold atoms. In contrast to currently existing schemes our protocol does not rely on any free propagation of atoms. Instead it is based on superpositions of fully confined atoms and state-dependent transport along a closed path. Using Ramsey sequences for an atomic clock, the accumulated Sagnac phase is encoded in the resulting population imbalance between two internal (clock) states. Using minimal models for the above protocol we analytically quantify limitations arising from atomic dynamics and finite temperature. We discuss an actual implementation of the interferometer with adiabatic radio-frequency potentials that is inherently robust against common mode noise as well as phase noise from the reference oscillator.

  17. On the energy of electric field in hydrogen atom

    E-Print Network [OSTI]

    Yuri Kornyushin

    2009-07-30T23:59:59.000Z

    It is shown that hydrogen atom is a unique object in physics having negative energy of electric field, which is present in the atom. This refers also to some hydrogen-type atoms: hydrogen anti-atom, atom composed of proton and antiproton, and positronium.

  18. Engineering atom-atom thermal entanglement via two-photon process

    E-Print Network [OSTI]

    Y. Q. Guo; L. Zhou; H. S. Song

    2005-09-21T23:59:59.000Z

    We study the system that two atoms simultaneously interact with a single-mode thermal field via different couplings and different spontaneous emission rates when two-photon process is involved. It is found that we indeed can employ the different couplings to produce the atom-atom thermal entanglement in two-photon process. The different atomic spontaneous emission rates are also utilizable in generating thermal entanglement. We also investigate the effect of the cavity leakage. To the initial atomic state $|ee> ,$a slight leakage can relieve the restriction of interaction time and we can obtain a large and steady entanglement.

  19. Laser trapping of {sup 21}Na atoms

    SciTech Connect (OSTI)

    Lu, Zheng-Tian

    1994-09-01T23:59:59.000Z

    This thesis describes an experiment in which about four thousand radioactive {sup 21}Na (t{sub l/2} = 22 sec) atoms were trapped in a magneto-optical trap with laser beams. Trapped {sup 21}Na atoms can be used as a beta source in a precision measurement of the beta-asymmetry parameter of the decay of {sup 21}Na {yields} {sup 21}Ne + {Beta}{sup +} + v{sub e}, which is a promising way to search for an anomalous right-handed current coupling in charged weak interactions. Although the number o trapped atoms that we have achieved is still about two orders of magnitude lower than what is needed to conduct a measurement of the beta-asymmetry parameter at 1% of precision level, the result of this experiment proved the feasibility of trapping short-lived radioactive atoms. In this experiment, {sup 21}Na atoms were produced by bombarding {sup 24}Mg with protons of 25 MeV at the 88 in. Cyclotron of Lawrence Berkeley Laboratory. A few recently developed techniques of laser manipulation of neutral atoms were applied in this experiment. The {sup 21}Na atoms emerging from a heated oven were first transversely cooled. As a result, the on-axis atomic beam intensity was increased by a factor of 16. The atoms in the beam were then slowed down from thermal speed by applying Zeeman-tuned slowing technique, and subsequently loaded into a magneto-optical trap at the end of the slowing path. The last two chapters of this thesis present two studies on the magneto-optical trap of sodium atoms. In particular, the mechanisms of magneto-optical traps at various laser frequencies and the collisional loss mechanisms of these traps were examined.

  20. Atomic magnetometer for human magnetoencephalograpy.

    SciTech Connect (OSTI)

    Schwindt, Peter; Johnson, Cort N.

    2010-12-01T23:59:59.000Z

    We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, the evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography.

  1. Scattering properties of dark atoms and molecules

    E-Print Network [OSTI]

    James M. Cline; Zuowei Liu; Guy D. Moore; Wei Xue

    2014-01-15T23:59:59.000Z

    There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in molecular form.

  2. Scattering properties of dark atoms and molecules

    E-Print Network [OSTI]

    Cline, James M; Moore, Guy; Xue, Wei

    2013-01-01T23:59:59.000Z

    There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in ...

  3. Ps-atom scattering at low energies

    E-Print Network [OSTI]

    Fabrikant, I I

    2015-01-01T23:59:59.000Z

    A pseudopotential for positronium-atom interaction, based on electron-atom and positron-atom phase shifts, is constructed, and the phase shifts for Ps-Kr and Ps-Ar scattering are calculated. This approach allows us to extend the Ps-atom cross sections, obtained previously in the impulse approximation [Phys. Rev. Lett. 112, 243201 (2014)], to energies below the Ps ionization threshold. Although experimental data are not available in this low-energy region, our results describe well the tendency of the measured cross sections to drop with decreasing velocity at $v<1$ a.u. Our results show that the effect of the Ps-atom van der Waals interaction is weak compared to the polarization interaction in electron-atom and positron-atom scattering. As a result, the Ps scattering length for both Ar and Kr is positive, and the Ramsauer-Townsend minimum is not observed for Ps scattering from these targets. This makes Ps scattering quite different from electron scattering in the low-energy region, in contrast to the inter...

  4. Studying coherence in ultra-cold atomic gases

    E-Print Network [OSTI]

    Miller, Daniel E. (Daniel Edward)

    2007-01-01T23:59:59.000Z

    This thesis will discuss the study of coherence properties of ultra-cold atomic gases. The atomic systems investigated include a thermal cloud of atoms, a Bose-Einstein condensate and a fermion pair condensate. In each ...

  5. Shielding and activity estimator for template-based nuclide identification methods

    DOE Patents [OSTI]

    Nelson, Karl Einar

    2013-04-09T23:59:59.000Z

    According to one embodiment, a method for estimating an activity of one or more radio-nuclides includes receiving one or more templates, the one or more templates corresponding to one or more radio-nuclides which contribute to a probable solution, receiving one or more weighting factors, each weighting factor representing a contribution of one radio-nuclide to the probable solution, computing an effective areal density for each of the one more radio-nuclides, computing an effective atomic number (Z) for each of the one more radio-nuclides, computing an effective metric for each of the one or more radio-nuclides, and computing an estimated activity for each of the one or more radio-nuclides. In other embodiments, computer program products, systems, and other methods are presented for estimating an activity of one or more radio-nuclides.

  6. Depth distribution of H-3, C-14 and Co-60 in decommissioning of the biological shielding concrete of KRR-2

    SciTech Connect (OSTI)

    Hong, S.B.; Kim, H.R.; Chung, R.H.; Chung, K.H.; Park, J.H. [Korea Atomic Energy Research Institute, Yuseong-gu, Daejeon (Korea, Republic of)

    2007-07-01T23:59:59.000Z

    The depth distributions of the gamma emitting nuclides, H-3 and C-14 activities were characterized for the activated biological shielding concrete from a decommissioning of Korea Research Reactor-2(TRIGA Mark-II) by using a commercially available tube furnace and a liquid scintillation counter. The HTO vapor and {sup 14}CO{sub 2} gas generated from the tube furnace were trapped in HNO{sub 3} and Carbosorb bubbler, respectively. The H-3 and C-14 activities were measured by the liquid scintillation counter. The specific activities of H-3 and C-14 were calculated by considering the concrete mass and the recovery factor of the tube furnace. The detection limits for H-3 and C-14 were 0.048 and 0.028 Bq/g respectively. The specific activity of the H-3 and C-14 tends to decrease exponentially as the depth of the concrete becomes deeper from the surface. In addition, the H-3 and C-14 activities were in good agreement with the Co-60 activities analyzed for the biological shielding concrete of KRR-2. (authors)

  7. 1984 Bibliography of atomic and molecular processes

    SciTech Connect (OSTI)

    Barnett, C.F.; Gilbody, H.B.; Gregory, D.C.; Griffin, P.M.; Havener, C.C.; Howard, A.M.; Kirkpatrick, M.I.; McDaniel, E.W.; Meyer, F.W.; Morgan, T.J. (comps.)

    1985-04-01T23:59:59.000Z

    This annotated bibliography includes papers on atomic and molecular processes published during 1984. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

  8. 1985 bibliography of atomic and molecular processes

    SciTech Connect (OSTI)

    Barnett, C.F.; Gilbody, H.B.; Gregory, D.C.; Griffin, P.M.; Havener, C.C.; Howald, A.M.; Kirkpatrick, M.I.; McDaniel, E.W.; Meyer, F.W.; Morgan, T.J. (comps.)

    1986-06-01T23:59:59.000Z

    This annotated bibliography includes papers on atomic and molecular processes published during 1985. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

  9. Gain narrowing in few-atom systems

    E-Print Network [OSTI]

    Tom Savels; Allard P. Mosk; Ad Lagendijk

    2006-05-31T23:59:59.000Z

    Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the atoms are in each other's near-field, the system exhibits large gain narrowing and spectral mode redistribution. The observed phenomena are more pronounced if the feedback is enhanced. Our system is to our knowledge the simplest exactly solvable microscopic system which shows the approach to laser oscillation.

  10. Cold Light from Hot Atoms and Molecules

    SciTech Connect (OSTI)

    Lister, Graeme [OSRAM SYLVANIA, CRSL, 71 Cherry Hill Drive, Beverly, MA (United States); Curry, John J. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    2011-05-11T23:59:59.000Z

    The introduction of rare earth atoms and molecules into lighting discharges led to great advances in efficacy of these lamps. Atoms such as Dy, Ho and Ce provide excellent radiation sources for lighting applications, with rich visible spectra, such that a suitable combination of these elements can provide high quality white light. Rare earth molecules have also proved important in enhancing the radiation spectrum from phosphors in fluorescent lamps. This paper reviews some of the current aspects of lighting research, particularly rare earth chemistry and radiation, and the associated fundamental atomic and molecular data.

  11. An Atom Trap Relying on Optical Pumping

    E-Print Network [OSTI]

    P. Bouyer; P. Lemonde; M. Ben Dahan; A. Michaud; C. Salomon; J. Dalibard

    2005-09-21T23:59:59.000Z

    We have investigated a new radiation pressure trap which relies on optical pumping and does not require any magnetic field. It employs six circularly polarized divergent beams and works on the red of a $J_{g} \\longrightarrow J_{e} = J_{g} + 1$ atomic transition with $J_{g} \\geq 1/2$. We have demonstrated this trap with cesium atoms from a vapour cell using the 852 nm $J_{g} = 4 \\longrightarrow J_{e} = 5$ resonance transition. The trap contained up to $3 \\cdot 10^{7}$ atoms in a cloud of $1/\\sqrt{e}$ radius of 330 $\\mu$m.

  12. The Manhattan Project: Making the atomic bomb

    SciTech Connect (OSTI)

    Gosling, F.G.

    1994-09-01T23:59:59.000Z

    This article is a short history of the origins and development of the American atomic bomb program during World War II. Beginning with the scientific developments of the pre-war years, the monograph details the role of US government in conducting a secret, nationwide enterprise that took science from the laboratory and into combat with an entirely new type of weapon. The monograph concludes with a discussion of the immediate postwar period, the debate over the Atomic Energy Act of 1946, and the founding of the Atomic Energy Commission.

  13. 1982 bibliography of atomic and molecular processes

    SciTech Connect (OSTI)

    Barnett, C.F.; Crandall, D.H.; Gilbody, H.B.; Gregory, D.C.; Kirkpatrick, M.I.; McDaniel, E.W.; McKnight, R.H.; Meyer, F.W.; Morgan, T.J.; Phaneuf, R.A. (comps.)

    1984-05-01T23:59:59.000Z

    This annotated bibliography includes papers on atomic and molecular processes published during 1982. Sources include scientific journals, conference proceedings, and books. Each entry is designated by one or more of the 114 categories of atomic and molecular processes used by the Controlled Fusion Atomic Data Center, Oak Ridge National Laboratory to classify data. Also indicated is whether the work was experimental or theoretical, what energy range was covered, what reactants were investigated, and the country of origin of the first author. Following the bibliographical listing, the entries are indexed according to the categories and according to reactants within each subcategory.

  14. Study on reduction in electric field, charged voltage, ion current and ion density under HVDC transmission lines by parallel shield wires

    SciTech Connect (OSTI)

    Amano, Y.; Sunaga, Y.

    1989-04-01T23:59:59.000Z

    An important problem in the design and operation of HVDC transmission lines is to reduce electrical field effects such as ion flow electrification of objects, electric field, ion current and ion density at ground level in the vicinity of HVDC lines. Several models of shield wire were tested with the Shiobara HVDC test line. The models contain typical stranded wires that are generally used to reduce field effects at ground level, neutral conductors placed at lower parts of the DC line, and an ''earth corona model'' to cancel positive or negative ions intentionally by generating ions having opposite polarity to ions flowing into the wire. This report describes the experimental results of the effects of these shield wires and a method to predict shielding effects.

  15. Analysis of Doppler Lidar Data Acquired During the Pentagon Shield Field Campaign

    SciTech Connect (OSTI)

    Newsom, Rob K.

    2011-04-14T23:59:59.000Z

    Observations from two coherent Doppler lidars deployed during the Pentagon Shield field campaign are analyzed in conjunction with other sensors to characterize the overall boundary-layer structure, and identify the dominant flow characteristics during the entire two-week field campaign. Convective boundary layer (CBL) heights and cloud base heights (CBH) are estimated from an analysis of the lidar signal-to-noise-ratio (SNR), and mean wind profiles are computed using a modified velocity-azimuth-display (VAD) algorithm. Three-dimensional wind field retrievals are computed from coordinated overlapping volume scans, and the results are analyzed by visualizing the flow in horizontal and vertical cross sections. The VAD winds show that southerly flows dominate during the two-week field campaign. Low-level jets (LLJ) were evident on all but two of the nights during the field campaign. The LLJs tended to form a couple hours after sunset and reach maximum strength between 03 and 07 UTC. The surface friction velocities show distinct local maxima during four nights when strong LLJs formed. Estimates of the convective boundary layer height and residual layer height are obtained through an analysis of the vertical gradient of the lidar signal-to-noise-ratio (SNR). Strong minimum in the SNR gradient often develops just above the surface after sunrise. This minimum is associated with the developing CBL, and increases rapidly during the early portion of the daytime period. On several days, this minimum continues to increase until about sunset. Secondary minima in the SNR gradient were also observed at higher altitudes, and are believed to be remnants of the CBL height from previous days, i.e. the residual layer height. The dual-Doppler analysis technique used in this study makes use of hourly averaged radial velocity data to produce three-dimensional grids of the horizontal velocity components, and the horizontal velocity variance. Visualization of horizontal and vertical cross sections of the dual-Doppler wind retrievals often indicated a jet-like flow feature over the Potomac River under southerly flow conditions. This linear flow feature is roughly aligned with the Potomac River corridor to the south of the confluence with the Anatostia River, and is most apparent at low levels (i.e. below ~150 m MSL). It is believed that this flow arises due to reduced drag over the water surface and when the large scale flow aligns with the Potomac River corridor. A so-called area-constrained VAD analysis generally confirmed the observations from the dual-Doppler analysis. When the large scale flow is southerly, wind speeds over the Potomac River are consistently larger than the at a site just to the west of the river for altitudes less than 100 m MSL. Above this level, the trend is somewhat less obvious. The data suggest that the depth of the wind speed maximum may be reduced by strong directional shear aloft.

  16. Interaction of an aluminum atom with a closed subshell metal atom: Spectroscopic analysis of AlZn

    E-Print Network [OSTI]

    Morse, Michael D.

    Interaction of an aluminum atom with a closed subshell metal atom: Spectroscopic analysis of Al-block main group element, aluminum, and the 3d series of transi- tion metal atoms. Although the bonding in Al

  17. acoustic wave atomization: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of fluid and acoustic computations, hybrid methodologies still Kohlenbach, Ulrich 12 Propagation of atomic matter waves inside an atom wave guide Quantum Physics (arXiv)...

  18. atomic emission spectrometry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    not the direction of the atom's motion. The conclusion is also evident from a simple energy relation: atomic spectral radiation is emitted as an orbiting electron consumes a...

  19. atomic photoabsorption process: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    individual sites within atom-trap arrays. Cecilia Muldoon; Lukas Brandt; Jian Dong; Dustin Stuart; Edouard Brainis; Matthew Himsworth; Axel Kuhn 2012-03-21 306 Atomic...

  20. Structure of ?-Alumina: Toward The Atomic Level Understanding...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    -Alumina: Toward The Atomic Level Understanding Of Transition Alumina Phases. Structure of -Alumina: Toward The Atomic Level Understanding Of Transition Alumina Phases....

  1. Atomic Energy Commission Explores Peaceful Uses of Nuclear Explosions...

    National Nuclear Security Administration (NNSA)

    Our Jobs Working at NNSA Blog Home About Us Our History NNSA Timeline Atomic Energy Commission Explores Peaceful Uses of ... Atomic Energy Commission Explores Peaceful...

  2. Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys. Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys....

  3. atomic carbon nanowires: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Page Topic Index 1 Electron Transport Properties of Atomic Carbon Nanowires between Graphene Electrodes CERN Preprints Summary: Long, stable and free-standing linear atomic...

  4. Isolation, Characterization of an Intermediate in an Oxygen Atom...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Characterization of an Intermediate in an Oxygen Atom-Transfer Reaction, and the Determination of the Bond Isolation, Characterization of an Intermediate in an Oxygen Atom-Transfer...

  5. atom trap trace: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1 An atom trap trace analysis system for measuring krypton contamination in xenon dark matter detectors Physics Websites Summary: An atom trap trace analysis system for measuring...

  6. Materials, Modules, and Systems: An Atoms to Autos Approach to...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Materials, Modules, and Systems: An Atoms to Autos Approach to Automotive Thermoelectric Systems Development Materials, Modules, and Systems: An Atoms to Autos Approach to...

  7. atomic number: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and relative number squeezing in dissociation of spatially inhomogeneous molecular condensates Physics Websites Summary: Atom-atom correlations and relative number squeezing in...

  8. atomic number density: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and relative number squeezing in dissociation of spatially inhomogeneous molecular condensates Quantum Physics (arXiv) Summary: We study atom-atom correlations and relative...

  9. atomic mass number: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and relative number squeezing in dissociation of spatially inhomogeneous molecular condensates Physics Websites Summary: Atom-atom correlations and relative number squeezing in...

  10. atomic number electron: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and relative number squeezing in dissociation of spatially inhomogeneous molecular condensates Physics Websites Summary: Atom-atom correlations and relative number squeezing in...

  11. atom interferometry measurement: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bose-condensed atoms . Open Access Theses and Dissertations Summary: ??Bose-Einstein condensates are coherent matter waves, produced by cooling gaseous atomic clouds to ultra-low...

  12. atomic wave packets: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Statistics of atomic populations in output coupled wave packets from Bose-Einstein condensates: Four-wave mixing Physics Websites Summary: Statistics of atomic populations in...

  13. atomic number range: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and relative number squeezing in dissociation of spatially inhomogeneous molecular condensates Physics Websites Summary: Atom-atom correlations and relative number squeezing in...

  14. atom interferometry progress: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bose-condensed atoms . Open Access Theses and Dissertations Summary: ??Bose-Einstein condensates are coherent matter waves, produced by cooling gaseous atomic clouds to ultra-low...

  15. Adsorption of Atoms and Molecules Physisorption

    E-Print Network [OSTI]

    Glashausser, Charles

    Adsorption of Atoms and Molecules Physisorption Chemisorption Surface Bonding Kinetics of Adsorption/Diffusion/Desorption (Scattering Dynamics) #12;Outcomes of Collision Process Rebound (elastically or inelastically) Elastic Scattering Inelastic Scattering Accomodation (thermalizing) Adsorption E V(r) r

  16. Atomic physics: An almost lightless laser

    E-Print Network [OSTI]

    Vuletic, Vladan

    Lasers are often described in terms of a light field circulating in an optical resonator system. Now a laser has been demonstrated in which the field resides primarily in the atomic medium that is used to generate the light.

  17. FREQUENCY DEPENDENT MULTIPOLE POLARIZABILITIES OF ATOMIC SYSTEMS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1259 FREQUENCY DEPENDENT MULTIPOLE POLARIZABILITIES OF ATOMIC SYSTEMS S. I. EASA and G. C. SHUKLA et d'helium. Abstract. 2014 A variational calculation for frequency dependent multipole 1978, Classification Physics Abstracts 31.10 The calculation of multipole polarizabilities

  18. Electronic transport in atomically thin layered materials

    E-Print Network [OSTI]

    Baugher, Britton William Herbert

    2014-01-01T23:59:59.000Z

    Electronic transport in atomically thin layered materials has been a burgeoning field of study since the discovery of isolated single layer graphene in 2004. Graphene, a semi-metal, has a unique gapless Dirac-like band ...

  19. Accurate capacitive metrology for atomic force microscopy

    E-Print Network [OSTI]

    Mazzeo, Aaron D. (Aaron David), 1979-

    2005-01-01T23:59:59.000Z

    This thesis presents accurate capacitive sensing metrology designed for a prototype atomic force microscope (AFM) originally developed in the MIT Precision Motion Control Lab. The capacitive measurements use a set of ...

  20. Quantum Structures of the Hydrogen Atom

    E-Print Network [OSTI]

    J. Jeknic-Dugic; M. Dugic; A. Francom; M. Arsenijevic

    2014-05-28T23:59:59.000Z

    Modern quantum theory introduces quantum structures (decompositions into subsystems) as a new discourse that is not fully comparable with the classical-physics counterpart. To this end, so-called Entanglement Relativity appears as a corollary of the universally valid quantum mechanics that can provide for a deeper and more elaborate description of the composite quantum systems. In this paper we employ this new concept to describe the hydrogen atom. We offer a consistent picture of the hydrogen atom as an open quantum system that naturally answers the following important questions: (a) how do the so called "quantum jumps" in atomic excitation and de-excitation occur? and (b) why does the classically and seemingly artificial "center-of-mass + relative degrees of freedom" structure appear as the primarily operable form in most of the experimental reality of atoms?

  1. United Nations Atomic Energy Commission stalls out

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    commission would be short-lived and would not result in the desired control of atomic energy. In the wake of the disappointing results of the Moscow meeting, the United States...

  2. Moving closer to the Atomic Energy Commission

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    in some way. On October 3, 1945 the president addressed Congress on the subject of atomic energy. Here he first mentioned the need for international agreements. Attempts were made...

  3. Quantum micro-mechanics with ultracold atoms

    E-Print Network [OSTI]

    Thierry Botter; Daniel Brooks; Subhadeep Gupta; Zhao-Yuan Ma; Kevin L. Moore; Kater W. Murch; Tom P. Purdy; Dan M. Stamper-Kurn

    2008-10-21T23:59:59.000Z

    In many experiments isolated atoms and ions have been inserted into high-finesse optical resonators for the study of fundamental quantum optics and quantum information. Here, we introduce another application of such a system, as the realization of cavity optomechanics where the collective motion of an atomic ensemble serves the role of a moveable optical element in an optical resonator. Compared with other optomechanical systems, such as those incorporating nanofabricated cantilevers or the large cavity mirrors of gravitational observatories, our cold-atom realization offers direct access to the quantum regime. We describe experimental investigations of optomechanical effects, such as the bistability of collective atomic motion and the first quantification of measurement backaction for a macroscopic object, and discuss future directions for this nascent field.

  4. Remote-State Prparation eines einzelnen Atoms

    E-Print Network [OSTI]

    Weinfurter, Harald

    Remote-State Präparation eines einzelnen Atoms Diplomarbeit am Department für Physik der Ludwig . . . . . . . . . . . . . . . . . . . . . 8 1.3.3 Remote-State-Präparation . . . . . . . . . . . . . . . . . . . . . 11 1.3.4 Zusammenfassung . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3 Remote-State-Präparation 31 3.1 Einleitung

  5. Electrical Analogs of Atomic Radiative Decay Processes

    E-Print Network [OSTI]

    Fontana, Peter R.; Srivastava, Rajendra P.

    1977-03-01T23:59:59.000Z

    Simple electrical circuits are analyzed, and the results show that for high frequencies they have frequency and time responses identical to the spontaneous radiative decays of atoms. As an illustration of the analogy a two-circuit electrical system...

  6. Atomic vapor spectroscopy in integrated photonic structures

    E-Print Network [OSTI]

    Ritter, Ralf; Pernice, Wolfram; Kübler, Harald; Pfau, Tilman; Löw, Robert

    2015-01-01T23:59:59.000Z

    We investigate an integrated optical chip immersed in atomic vapor providing several waveguide geometries for spectroscopy applications. The narrow-band transmission through a silicon nitride waveguide and interferometer is altered when the guided light is coupled to a vapor of rubidium atoms via the evanescent tail of the waveguide mode. We use grating couplers to couple between the waveguide mode and the radiating wave, which allow for addressing arbitrary coupling positions on the chip surface. The evanescent atom-light interaction can be numerically simulated and shows excellent agreement with our experimental data. This work demonstrates a next step towards miniaturization and integration of alkali atom spectroscopy and provides a platform for further fundamental studies of complex waveguide structures.

  7. Hydrogen atom in rotationally invariant noncommutative space

    E-Print Network [OSTI]

    Kh. P. Gnatenko; V. M. Tkachuk

    2014-11-03T23:59:59.000Z

    We consider the noncommutative algebra which is rotationally invariant. The hydrogen atom is studied in a rotationally invariant noncommutative space. We find the corrections to the energy levels of the hydrogen atom up to the second order in the parameter of noncommutativity. The upper bound of the parameter of noncommutativity is estimated on the basis of the experimental results for 1s-2s transition frequency.

  8. Atomic resolution images of graphite in air

    SciTech Connect (OSTI)

    Grigg, D.A.; Shedd, G.M.; Griffis, D.; Russell, P.E.

    1988-12-01T23:59:59.000Z

    One sample used for proof of operation for atomic resolution in STM is highly oriented pyrolytic graphite (HOPG). This sample has been imaged with many different STM`s obtaining similar results. Atomic resolution images of HOPG have now been obtained using an STM designed and built at the Precision Engineering Center. This paper discusses the theoretical predictions and experimental results obtained in imaging of HOPG.

  9. Controlling the Ratchet Effect for Cold Atoms

    E-Print Network [OSTI]

    Anatole Kenfack; Jiangbin Gong; Arjendu K. Pattanayak

    2007-11-27T23:59:59.000Z

    Low-order quantum resonances manifested by directed currents have been realized with cold atoms. Here we show that by increasing the strength of an experimentally achievable delta-kicking ratchet potential, quantum resonances of a very high order may naturally emerge and can induce larger ratchet currents than low-order resonances, with the underlying classical limit being fully chaotic. The results offer a means of controlling quantum transport of cold atoms.

  10. ac-driven atomic quantum motor

    E-Print Network [OSTI]

    A. V. Ponomarev; S. Denisov; P. Hanggi

    2009-06-09T23:59:59.000Z

    We invent an ac-driven quantum motor consisting of two different, interacting ultracold atoms placed into a ring-shaped optical lattice and submerged in a pulsating magnetic field. While the first atom carries a current, the second one serves as a quantum starter. For fixed zero-momentum initial conditions the asymptotic carrier velocity converges to a unique non-zero value. We also demonstrate that this quantum motor performs work against a constant load.

  11. From Lattice Gauge Theories to Hydrogen Atoms

    E-Print Network [OSTI]

    Manu Mathur; T. P. Sreeraj

    2014-10-13T23:59:59.000Z

    Using canonical transformations we obtain a complete and most economical realization of the loop or physical Hilbert space of pure $SU(2)_{2+1}$ lattice gauge theory in terms of Wigner coupled Hilbert spaces of hydrogen atoms. One hydrogen atom is assigned to every plaquette of the lattice. The SU(2) gauge theory loop basis states over a plaquette are the bound energy eigenstates $|n l m>$ of the corresponding hydrogen atom. The Wigner couplings of these hydrogen atom energy eigenstates on different plaquettes provide a complete SU(2) gauge theory loop basis on the entire lattice. The loop basis is invariant under simultaneous rotations of all hydrogen atoms. The dual description of this basis diagonalizes all Wilson loop operators and is given in terms of hyperspherical harmonics on the SU(2) group manifold $S^3$. The SU(2) loop dynamics is governed by a "SU(2) spin Hamiltonian" without any gauge fields. The relevance of the hydrogen atom basis and its dynamical symmetry group SO(4,2) in SU(2) loop dynamics in weak coupling continuum limit ($g^2\\rightarrow 0$) is emphasized.

  12. Excess optical quantum noise in atomic sensors

    E-Print Network [OSTI]

    Irina Novikova; Eugeniy E. Mikhailov; Yanhong Xiao

    2014-10-14T23:59:59.000Z

    Enhanced nonlinear optical response of a coherent atomic medium is the basis for many atomic sensors, and their performance is ultimately limited by the quantum fluctuations of the optical read-out. Here we demonstrate that off-resonant interactions can significantly modify the quantum noise of the optical field, even when their effect on the mean signal is negligible. We illustrate this concept by using an atomic magnetometer based on the nonlinear Faraday effect: the rotation of the light polarization is mainly determined by the resonant light-induced spin alignment, which alone does not change the photon statistics of the optical probe. Yet, we found that the minimum noise of output polarization rotation measurements is above the expected shot noise limit. This excess quantum noise is due to off-resonant coupling and grows with atomic density. We also show that the detection scheme can be modified to reduce the measured quantum noise (even below the shot-noise limit) but only at the expense of the reduced rotational sensitivity. These results show the existence of previously unnoticed factors in fundamental limitations in atomic magnetometry and could have impacts in many other atom-light based precision measurements.

  13. Atoms 2014, 2, 157-177; doi:10.3390/atoms2020157 OPEN ACCESS

    E-Print Network [OSTI]

    Atoms 2014, 2, 157-177; doi:10.3390/atoms2020157 OPEN ACCESS atomsISSN 2218-2004 www]: = ne2 ¯h2 - dt1 t1 - dt2E(t1)·E(t2)ei (t1-t2) (3) where E(t1)·E(t2) = 2 3 0 vf(v)dv max 0 dE(t1

  14. Atoms for peace and war, 1953-1961: Eisenhower and the Atomic Energy Commission

    SciTech Connect (OSTI)

    Hewlett, Richard G.; Holl, Jack M.

    1989-12-01T23:59:59.000Z

    This third volume in the official history of the U.S. Atomic Energy Commission covers the years of the Eisenhower Administration.

  15. Understanding space weather to shield society: A global road map for 2015-2025 commissioned by COSPAR and ILWS

    E-Print Network [OSTI]

    Schrijver, Carolus J; Aylward, Alan D; Denardini, Clezio M; Gibson, Sarah E; Glover, Alexi; Gopalswamy, Nat; Grande, Manuel; Hapgood, Mike; Heynderickx, Daniel; Jakowski, Norbert; Kalegaev, Vladimir V; Lapenta, Giovanni; Linker, Jon A; Liu, Siqing; Mandrini, Cristina H; Mann, Ian R; Nagatsuma, Tsutomu; Nandi, Dibyendu; Obara, Takahiro; O'Brien, T Paul; Onsager, Terrance; Opgenoorth, Hermann J; Terkildsen, Michael; Valladares, Cesar E; Vilmer, Nicole

    2015-01-01T23:59:59.000Z

    There is a growing appreciation that the environmental conditions that we call space weather impact the technological infrastructure that powers the coupled economies around the world. With that comes the need to better shield society against space weather by improving forecasts, environmental specifications, and infrastructure design. [...] advanced understanding of space weather requires a coordinated international approach to effectively provide awareness of the processes within the Sun-Earth system through observation-driven models. This roadmap prioritizes the scientific focus areas and research infrastructure that are needed to significantly advance our understanding of space weather of all intensities and of its implications for society. Advancement of the existing system observatory through the addition of small to moderate state-of-the-art capabilities designed to fill observational gaps will enable significant advances. Such a strategy requires urgent action: key instrumentation needs to be sustaine...

  16. BWR spent fuel storage cask performance test. Volume 1. Cask handling experience and decay heat, heat transfer, and shielding data

    SciTech Connect (OSTI)

    McKinnon, M.A.; Doman, J.W.; Tanner, J.E.; Guenther, R.J.; Creer, J.M.; King, C.E.

    1986-02-01T23:59:59.000Z

    This report documents a heat transfer and shielding performance test conducted on a Ridihalgh, Eggers and Associates REA 2023 boiling water reactor (BWR) spent fuel storage cask. The testing effort consisted of three parts: pretest preparations, performance testing, and post-test activities. Pretest preparations included conducting cask handling dry runs and characterizing BWR spent fuel assemblies from Nebraska Public Power District's Cooper Nuclear Station. The performance test matrix included 14 runs consisting of two loadings, two cask orientations, and three backfill environments. Post-test activities included calorimetry and axial radiation scans of selected fuel assemblies, in-basin sipping of each assembly, crud collection, video and photographic scans, and decontamination of the cask interior and exterior.

  17. The estimation of the 210Pb bremsstrahlung contribution to the background of lead shielded {gamma}-spectrometers

    SciTech Connect (OSTI)

    Mrdja, Dusan; Bikit, Istvan; Veskovic, Miroslav; Slivka, Jaroslav; Conkic, Ljiljana; Varga, Ester [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21 000 Novi Sad (Serbia and Montenegro)

    2006-04-26T23:59:59.000Z

    The 46.5 keV {gamma}-intensity of 210Pb in the background can be easily reduced by inner lining, but the bremsstrahlung from the 1.2 MeV maximal energy {beta}-decay will reach the lead shielded Ge detector. The spectrum of this bremsstrahlung is calculated by numerically fitting the {beta}-spectrum and integrating the Koch-Motz formula. The adsorption of the bremsstrahlung spectrum in the lead is calculated by the effective solid angle algorithm by comparison with the measured background spectrum. It is shown, that for the lead with 25 Bq/kg of 210Pb, at 100 keV the bremsstrahlung contribution to the background is about 20%.

  18. Identification of Unknown Interface Locations in a Source/Shield System Using the Mesh Adaptive Direct Search Method

    SciTech Connect (OSTI)

    Armstrong, Jerawan C. [Los Alamos National Laboratory; Favorite, Jeffrey A. [Los Alamos National Laboratory

    2012-06-20T23:59:59.000Z

    The Levenberg-Marquardt (or simply Marquardt) and differential evolution (DE) optimization methods were recently applied to solve inverse transport problems. The Marquardt method is fast but convergence of the method is dependent on the initial guess. While it has been shown to work extremely well at finding an optimum independent of the initial guess, the DE method does not provide a global optimal solution in some problems. In this paper, we apply the Mesh Adaptive Direct Search (MADS) algorithm to solve the inverse problem of material interface location identification in one-dimensional spherical radiation source/shield systems, and we compare the results obtained by MADS to those obtained by Levenberg-Marquardt and DE.

  19. 29Counting Atoms in a Molecule The complex molecule Propanal

    E-Print Network [OSTI]

    29Counting Atoms in a Molecule The complex molecule Propanal was discovered in a dense interstellar is the ratio of carbon atoms to hydrogen atoms in propanal? Problem 4 - If the mass of a hydrogen atom of a propanal molecule in AMUs? Problem 5 - What is the complete chemical formula for propanal? C3 H __ O

  20. ATOMIC PHYSICS DMITRY BUDKER | DEREK F. KIMBALL | DAVID P. DEMILLE

    E-Print Network [OSTI]

    Pines, Alexander

    symmetries, atomic magnetometers and frequency comb metrology with ultra-short laser pulses. Dmitry Budker

  1. With BlueCard Worldwide you can explore the world with peace of mind. Like your passport, always carry your Blue Cross and Blue Shield of Oklahoma

    E-Print Network [OSTI]

    Oklahoma, University of

    With BlueCard Worldwide you can explore the world with peace of mind. Like your passport, always carry your Blue Cross and Blue Shield of Oklahoma (BCBSOK) identification (ID) card with you when you travel or live abroad. Through the BlueCard Worldwide program, you have access to medical assistance

  2. ANTHEM BLUE CROSS AND BLUE SHIELD You may select from two separate dental care plans to meet your individual needs. Premium cost

    E-Print Network [OSTI]

    - 34 - ANTHEM BLUE CROSS AND BLUE SHIELD You may select from two separate dental care plans to meet two choices are: Anthem Blue Dental PPO Plus Anthem Blue Dental PPO NOTE: Children are eligible in retirement. PERA retirement benefits are based on your highest three years of earnings. Anthem Blue Dental

  3. CHEIBA Multi-Option for 0111.v.10-20-10 1 HMO Colorado/Anthem Blue Cross and Blue Shield

    E-Print Network [OSTI]

    CHEIBA Multi-Option for 0111.v.10-20-10 1 HMO Colorado/Anthem Blue Cross and Blue Shield Colorado Higher Education Insurance Benefits Alliance Effective January 1, 2011 PART A: TYPE OF COVERAGE Blue. Coinsurance and copayment options reflect the amount the covered person will pay. BlueAdvantage HMO

  4. {sup 33}S hyperfine interactions in H{sub 2}S and SO{sub 2} and revision of the sulfur nuclear magnetic shielding scale

    SciTech Connect (OSTI)

    Helgaker, Trygve, E-mail: t.u.helgaker@kjemi.uio.no [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, N-0315 Oslo (Norway)] [Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Oslo, N-0315 Oslo (Norway); Gauss, Jürgen, E-mail: gauss@uni-mainz.de [Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz (Germany)] [Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz (Germany); Cazzoli, Gabriele, E-mail: gabriele.cazzoli@unibo.it; Puzzarini, Cristina, E-mail: cristina.puzzarini@unibo.it [Dipartimento di Chimica “Giacomo Ciamician,” Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy)] [Dipartimento di Chimica “Giacomo Ciamician,” Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy)

    2013-12-28T23:59:59.000Z

    Using the Lamb-dip technique, the hyperfine structure in the rotational spectra of H{sub 2}{sup 33}S and {sup 33}SO{sub 2} has been resolved and the corresponding parameters—that is, the sulfur quadrupole-coupling and spin–rotation tensors—were determined. The experimental parameters are in good agreement with results from high-level coupled-cluster calculations, provided that up to quadruple excitations are considered in the cluster operator, sufficiently large basis sets are used, and vibrational corrections are accounted for. The {sup 33}S spin-rotation tensor for H{sub 2}S has been used to establish a new sulfur nuclear magnetic shielding scale, combining the paramagnetic part of the shielding as obtained from the spin–rotation tensor with a calculated value for the diamagnetic part as well as computed vibrational and temperature corrections. The value of 716(5) ppm obtained in this way for the sulfur shielding of H{sub 2}S is in good agreement with results from high-accuracy quantum-chemical calculations but leads to a shielding scale that is about 28 ppm lower than the one suggested previously in the literature, based on the {sup 33}S spin-rotation constant of OCS.

  5. Isolating and moving single atoms using silicon nanocrystals

    DOE Patents [OSTI]

    Carroll, Malcolm S. (Albuquerque, NM)

    2010-09-07T23:59:59.000Z

    A method is disclosed for isolating single atoms of an atomic species of interest by locating the atoms within silicon nanocrystals. This can be done by implanting, on the average, a single atom of the atomic species of interest into each nanocrystal, and then measuring an electrical charge distribution on the nanocrystals with scanning capacitance microscopy (SCM) or electrostatic force microscopy (EFM) to identify and select those nanocrystals having exactly one atom of the atomic species of interest therein. The nanocrystals with the single atom of the atomic species of interest therein can be sorted and moved using an atomic force microscope (AFM) tip. The method is useful for forming nanoscale electronic and optical devices including quantum computers and single-photon light sources.

  6. Atomic-level imaging, processing and characterization of semiconductor surfaces

    DOE Patents [OSTI]

    Kazmerski, L.L.

    1995-08-22T23:59:59.000Z

    A method for selecting and removing single specific atoms from a solid material surface uses photon biasing to break down bonds that hold the selected atom in the lattice and to reduce barrier effects that hold the atom from transferring to a probe. The photon bias is preferably light or other electromagnetic radiation with a wavelength and frequency that approximately matches the wave function of the target atom species to be removed to induce high energy, selective thermionic-like vibration. An electric field potential is then applied between the probe and the surface of the solid material to pull the atom out of the lattice and to transfer the atom to the probe. Different extrinsic atoms can be installed in the lattice sites that are vacated by the removed atoms by using a photon bias that resonates the extrinsic atom species, reversing polarity of the electric field, and blowing gas comprising the extrinsic atoms through a hollow catheter probe. 8 figs.

  7. Atomic-level imaging, processing and characterization of semiconductor surfaces

    DOE Patents [OSTI]

    Kazmerski, Lawrence L. (Lakewood, CO)

    1995-01-01T23:59:59.000Z

    A method for selecting and removing single specific atoms from a solid material surface uses photon biasing to break down bonds that hold the selected atom in the lattice and to reduce barrier effects that hold the atom from transferring to a probe. The photon bias is preferably light or other electromagnetic radiation with a wavelength and frequency that approximately matches the wave function of the target atom species to be removed to induce high energy, selective thermionic-like vibration. An electric field potential is then applied between the probe and the surface of the solid material to pull the atom out of the lattice and to transfer the atom to the probe. Different extrinsic atoms can be installed in the lattice sites that are vacated by the removed atoms by using a photon bias that resonates the extrinsic atom species, reversing polarity of the electric field, and blowing gas comprising the extrinsic atoms through a hollow catheter probe.

  8. Concepts and Tests for the Remote-Controlled Dismantling of the Biological Shield and Form work of the KNK Reactor - 13425

    SciTech Connect (OSTI)

    Neff, Sylvia; Graf, Anja; Petrick, Holger; Rothschmitt, Stefan [WAK Rueckbau- und Entsorgungs- GmbH, P.O.Box 12 63, 76339 Eggenstein- Leopoldshafen (Germany)] [WAK Rueckbau- und Entsorgungs- GmbH, P.O.Box 12 63, 76339 Eggenstein- Leopoldshafen (Germany); Klute, Stefan [Siempelkamp Nukleartechnik GmbH, Am Taubenfeld 25/1, 69123 Heidelberg (Germany)] [Siempelkamp Nukleartechnik GmbH, Am Taubenfeld 25/1, 69123 Heidelberg (Germany); Stanke, Dieter [Siempelkamp NIS Ingenieurgesellschaft mbH, Industriestrasse 13, 63755 Alzenau (Germany)] [Siempelkamp NIS Ingenieurgesellschaft mbH, Industriestrasse 13, 63755 Alzenau (Germany)

    2013-07-01T23:59:59.000Z

    The compact sodium-cooled nuclear reactor facility Karlsruhe (KNK), a prototype Fast Breeder, is currently in an advanced stage of dismantling. Complete dismantling is based on 10 partial licensing steps. In the frame of the 9. decommissioning permit, which is currently ongoing, the dismantling of the biological shield is foreseen. The biological shield consists of heavy reinforced concrete with built-in steel fitments, such as form-work of the reactor tank, pipe sleeves, ventilation channels, and measuring devices. Due to the activation of the inner part of the biological shield, dismantling has to be done remote-controlled. During a comprehensive basic design phase a practical dismantling strategy was developed. Necessary equipment and tools were defined. Preliminary tests revealed that hot wire plasma cutting is the most favorable cutting technology due to the geometrical boundary conditions, the varying distance between cutter and material, and the heavy concrete behind the steel form-work. The cutting devices will be operated remotely via a carrier system with an industrial manipulator. The carrier system has expandable claws to adjust to the varying diameter of the reactor shaft during dismantling progress. For design approval of this prototype development, interaction between manipulator and hot wire plasma cutting was tested in a real configuration. For the demolition of the concrete structure, an excavator with appropriate tools, such as a hydraulic hammer, was selected. Other mechanical cutting devices, such as a grinder or rope saw, were eliminated because of concrete containing steel spheres added to increase the shielding factor of the heavy concrete. Dismantling of the biological shield will be done in a ring-wise manner due to static reasons. During the demolition process, the excavator is positioned on its tripod in three concrete recesses made prior to the dismantling of the separate concrete rings. The excavator and the manipulator carrier system will be operated alternately. Main boundary condition for all the newly designed equipment is the decommissioning housing of limited space within the reactor building containment. To allow for a continuous removal of the concrete rubble, an additional opening on the lowest level of the reactor shaft will be made. All equipment and the interaction of the tools have to be tested before use in the controlled area. Therefore a full-scale model of the biological shield will be provided in a mock-up. The tests will be performed in early 2014. The dismantling of the biological shield is scheduled for 2015. (authors)

  9. Chapter 44. Cooling and Trapping Neutral Atoms Cooling and Trapping Neutral Atoms

    E-Print Network [OSTI]

    transition. This year, we made progress in developing novel detection and cooling techniques. 1. SpinChapter 44. Cooling and Trapping Neutral Atoms 44-1 Cooling and Trapping Neutral Atoms RLE Groups in optical lattices. Additional cooling methods will be needed to reach this very interesting temperature

  10. Hydrogen atom in de Sitter spaces

    E-Print Network [OSTI]

    O. V. Veko; K. V. Kazmerchuk; E. M. Ovsiyuk; V. M. Red'kov; A. M. Ishkhanyan

    2014-12-28T23:59:59.000Z

    The hydrogen atom theory is developed for the de Sitter and anti de Sitter spaces on the basis of the Klein-Gordon-Fock wave equation in static coordinates. In both models, after separation of the variables, the problem is reduced to the general Heun equation, a second order linear differential equation having four regular singular points. A qualitative examination shows that the energy spectrum for the hydrogen atom in the de Sitter space should be quasi-stationary, and the atom should be unstable. We derive an approximate expression for energy levels within the quasi-classical approach and estimate the probability of decay of the atom. A similar analysis shows that in the anti de Sitter model the hydrogen atom should be stable in the quantum-mechanical sense. Using the quasi-classical approach, we derive approximate formulas for energy levels for this case as well. Finally, we present the extension to the case of a spin 1/2 particle for both de Sitter models. This extension leads to complicated differential equations with 8 singular points.

  11. Method and apparatus for atomic imaging

    DOE Patents [OSTI]

    Saldin, Dilano K. (Milwaukee, WI); de Andres Rodriquez, Pedro L. (Madrid, ES)

    1993-01-01T23:59:59.000Z

    A method and apparatus for three dimensional imaging of the atomic environment of disordered adsorbate atoms are disclosed. The method includes detecting and measuring the intensity of a diffuse low energy electron diffraction pattern formed by directing a beam of low energy electrons against the surface of a crystal. Data corresponding to reconstructed amplitudes of a wave form is generated by operating on the intensity data. The data corresponding to the reconstructed amplitudes is capable of being displayed as a three dimensional image of an adsorbate atom. The apparatus includes a source of a beam of low energy electrons and a detector for detecting the intensity distribution of a DLEED pattern formed at the detector when the beam of low energy electrons is directed onto the surface of a crystal. A device responsive to the intensity distribution generates a signal corresponding to the distribution which represents a reconstructed amplitude of a wave form and is capable of being converted into a three dimensional image of the atomic environment of an adsorbate atom on the crystal surface.

  12. Dynamic polarizabilities of rare-earth-metal atoms and dispersion coefficients for their interaction with helium atoms

    E-Print Network [OSTI]

    Chu, Xi

    Dynamic polarizabilities of rare-earth-metal atoms and dispersion coefficients; published 29 March 2007 The dynamic scalar and tensor polarizabilities of the rare-earth-metal atoms coefficients for the interactions of the rare-earth-metal atoms with helium atoms. The static polarizabilities

  13. Optical pumping of a lithium atomic beam for atom interferometry J. Gillot, A. Gauguet, M. Buchner, and J. Vigue

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Optical pumping of a lithium atomic beam for atom interferometry J. Gillot, A. Gauguet, M. B.vigue@irsamc.ups-tlse.fr (Dated: May 29, 2013) We apply optical pumping to prepare the lithium beam of our atom interferometer in a single hyperfine-Zeeman sublevel: we use two components of the D1-line for pumping the 7 Li atoms

  14. Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint

    SciTech Connect (OSTI)

    Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

    2011-07-01T23:59:59.000Z

    Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve full atomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface is maximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.

  15. Atomic multipole relaxation rates near surfaces

    E-Print Network [OSTI]

    J. A. Crosse; Stefan Scheel

    2010-08-13T23:59:59.000Z

    The spontaneous relaxation rates for an atom in free space and close to an absorbing surface are calculated to various orders of the electromagnetic multipole expansion. The spontaneous decay rates for dipole, quadrupole and octupole transitions are calculated in terms of their respective primitive electric multipole moments and the magnetic relaxation rate is calculated for the dipole and quadrupole transitions in terms of their respective primitive magnetic multipole moments. The theory of electromagnetic field quantization in magnetoelectric materials is used to derive general expressions for the decay rates in terms of the dyadic Green function. We focus on the decay rates in free space and near an infinite half space. For the decay of atoms near to an absorbing dielectric surface we find a hierarchy of scaling laws depending on the atom-surface distance z.

  16. Atom interferometry in an optical cavity

    E-Print Network [OSTI]

    Paul Hamilton; Matt Jaffe; Justin M. Brown; Lothar Maisenbacher; Brian Estey; Holger Müller

    2014-09-25T23:59:59.000Z

    We propose and demonstrate a new scheme for atom interferometry, using light pulses inside an optical cavity as matter wave beamsplitters. The cavity provides power enhancement, spatial filtering, and a precise beam geometry, enabling new techniques such as low power beamsplitters ($modest power, or new self-aligned interferometer geometries utilizing the transverse modes of the optical cavity. As a first demonstration, we obtain Ramsey-Raman fringes with $>75\\%$ contrast and measure the acceleration due to gravity, $\\mathit{g}$, to $60 \\mathrm{\\mu \\mathit{g} / \\sqrt{Hz}}$ resolution in a Mach-Zehnder geometry. We use $>10^7$ cesium atoms in the compact mode volume ($600 \\mathrm{\\mu m}$ $1/e^2$ waist) of the cavity and show trapping of atoms in higher transverse modes. This work paves the way toward compact, high sensitivity, multi-axis interferometry.

  17. Searching for dark matter with helium atom

    E-Print Network [OSTI]

    Imre Ferenc Barna

    2006-08-10T23:59:59.000Z

    With the help of the boost operator we can model the interaction between a weakly interacting particle(WIMP) of dark matter(DAMA) and an atomic nuclei. Via this "kick" we calculate the total electronic excitation cross section of the helium atom. The bound spectrum of He is calculated through a diagonalization process with a configuration interaction (CI) wavefunction built up from Slater orbitals. All together 19 singly- and doubly-excited atomic sates were taken with total angular momenta of L=0,1 and 2. Our calculation may give a rude estimation about the magnitude of the total excitation cross section which could be measured in later scintillator experiments. The upper limit of the excitation cross section is $9.7\\cdot 10^{-8}$ barn.

  18. Atom Interferometers and the Gravitational Redshift

    E-Print Network [OSTI]

    Supurna Sinha; Joseph Samuel

    2011-05-16T23:59:59.000Z

    From the principle of equivalence, Einstein predicted that clocks slow down in a gravitational field. Since the general theory of relativity is based on the principle of equivalence, it is essential to test this prediction accurately. Muller, Peters and Chu claim that a reinterpretation of decade old experiments with atom interferometers leads to a sensitive test of this gravitational redshift effect at the Compton frequency. Wolf et al dispute this claim and adduce arguments against it. In this article, we distill these arguments to a single fundamental objection: an atom is NOT a clock ticking at the Compton frequency. We conclude that atom interferometry experiments conducted to date do not yield such sensitive tests of the gravitational redshift. Finally, we suggest a new interferometric experiment to measure the gravitational redshift, which realises a quantum version of the classical clock "paradox".

  19. New charge radius relations for atomic nuclei

    E-Print Network [OSTI]

    B. H. Sun; Y. Lu; J. P. Peng; C. Y. Liu; Y. M. Zhao

    2014-11-24T23:59:59.000Z

    We show that the charge radii of neighboring atomic nuclei, independent of atomic number and charge, follow remarkably very simple relations, despite the fact that atomic nuclei are complex finite many-body systems governed by the laws of quantum mechanics. These relations can be understood within the picture of independent-particle motion and by assuming neighboring nuclei having similar pattern in the charge density distribution. A root-mean-square (rms) deviation of 0.0078 fm is obtained between the predictions in these relations and the experimental values, i.e., a comparable precision as modern experimental techniques. Such high accuracy relations are very useful to check the consistence of nuclear charge radius surface and moreover to predict unknown nuclear charge radii, while large deviations from experimental data is seen to reveal the appearance of nuclear shape transition or coexsitence.

  20. Feedback Cooling of a Single Neutral Atom

    E-Print Network [OSTI]

    Markus Koch; Christian Sames; Alexander Kubanek; Matthias Apel; Maximilian Balbach; Alexei Ourjoumtsev; Pepijn W. H. Pinkse; Gerhard Rempe

    2010-10-15T23:59:59.000Z

    We demonstrate feedback cooling of the motion of a single rubidium atom trapped in a high-finesse optical resonator to a temperature of about 160 \\mu K. Time-dependent transmission and intensity-correlation measurements prove the reduction of the atomic position uncertainty. The feedback increases the 1/e storage time into the one second regime, 30 times longer than without feedback. Feedback cooling therefore rivals state-of-the-art laser cooling, but with the advantages that it requires less optical access and exhibits less optical pumping.