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Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

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

E-Print Network [OSTI]

(&?/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...

Sarder, Md. Maksudur Rahaman

1999-01-01T23:59:59.000Z

2

Atom interferometry in space: Thermal management and magnetic shielding  

SciTech Connect (OSTI)

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.

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

3

A study of form-principles affording shielding from atomic fallout  

E-Print Network [OSTI]

"). 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...

Lanford, Samuel Taylor

1963-01-01T23:59:59.000Z

4

Thermocouple shield  

DOE Patents [OSTI]

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.

Ripley, Edward B. (Knoxville, TN)

2009-11-24T23:59:59.000Z

5

Shielding vacuum fluctuations with graphene  

E-Print Network [OSTI]

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.

Sofia Ribeiro; Stefan Scheel

2014-03-14T23:59:59.000Z

6

Magnetic shielding  

DOE Patents [OSTI]

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.

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

1985-02-12T23:59:59.000Z

7

Early test facilities and analytic methods for radiation shielding: Proceedings  

SciTech Connect (OSTI)

This report represents a compilation of eight papers presented at the 1992 American Nuclear Society/European Nuclear Society International Meeting. The meeting is of special significance since it commemorates the fiftieth anniversary of the first controlled nuclear chain reaction. 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. The paper titles are good indicators of their content and are: (1) The origin of radiation shielding research: The Oak Ridge experience, (2) Shielding research at the hanford site, (3) Aircraft shielding experiments at General Dynamics Fort Worth, 1950-1962, (4) Where have the neutrons gone , a history of the tower shielding facility, (5) History and evolution of buildup factors, (6) Early shielding research at Bettis atomic power laboratory, (7) UK reactor shielding: then and now, (8) A very personal view of the development of radiation shielding theory.

Ingersoll, D.T. (comp.) (Oak Ridge National Lab., TN (United States)); Ingersoll, J.K. (comp.) (Tec-Com, Knoxville, TN (United States))

1992-11-01T23:59:59.000Z

8

INTOR radiation shielding for personnel access  

SciTech Connect (OSTI)

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.

Gohar, Y.; Abdou, M.

1981-01-01T23:59:59.000Z

9

Gamma ray detector shield  

DOE Patents [OSTI]

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.

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

1985-08-26T23:59:59.000Z

10

Hysteresis prediction inside magnetic shields and application  

SciTech Connect (OSTI)

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.

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

11

Adhesive particle shielding  

DOE Patents [OSTI]

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.

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

2009-01-06T23:59:59.000Z

12

SHIELD certification package  

SciTech Connect (OSTI)

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.

Boman, C.

1992-02-01T23:59:59.000Z

13

Microscreen radiation shield for thermoelectric generator  

DOE Patents [OSTI]

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.

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

1990-01-01T23:59:59.000Z

14

Radiation shielding composition  

DOE Patents [OSTI]

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.

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

2000-12-26T23:59:59.000Z

15

Radiation shielding composition  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

16

Radiation shielding composition  

DOE Patents [OSTI]

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.

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

1998-07-28T23:59:59.000Z

17

Composition for radiation shielding  

DOE Patents [OSTI]

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.

Kronberg, James W. (Aiken, SC)

1994-01-01T23:59:59.000Z

18

Lightweight blast shield  

DOE Patents [OSTI]

A tandem warhead missile arrangement that has a composite material housing structure with a first warhead mounted at one end and a second warhead mounted near another end of the composite structure with a dome shaped composite material blast shield mounted between the warheads to protect the second warhead from the blast of the first warhead.

Mixon, Larry C. (Madison, AL); Snyder, George W. (Huntsville, AL); Hill, Scott D. (Toney, AL); Johnson, Gregory L. (Decatur, AL); Wlodarski, J. Frank (Huntsville, AL); von Spakovsky, Alexis P. (Huntsville, AL); Emerson, John D. (Arab, AL); Cole, James M. (Huntsville, AL); Tipton, John P. (Huntsville, AL)

1991-01-01T23:59:59.000Z

19

The Tower Shielding Facility: Its glorious past  

SciTech Connect (OSTI)

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.

Muckenthaler, F.J.

1997-05-07T23:59:59.000Z

20

Review Article RADIATION SHIELDING TECHNOLOGY  

E-Print Network [OSTI]

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

Shultis, J. Kenneth

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

SUPERCONDUCTING SHIELDING By W. O. HAMILTON,  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

22

Gas shielding apparatus  

DOE Patents [OSTI]

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.

Brandt, D.

1984-06-05T23:59:59.000Z

23

Composition for radiation shielding  

DOE Patents [OSTI]

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.

Kronberg, J.W.

1994-08-02T23:59:59.000Z

24

Actively driven thermal radiation shield  

DOE Patents [OSTI]

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.

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

25

Drip Shield Emplacement Gantry Concept  

SciTech Connect (OSTI)

This design analysis has shown that, on a conceptual level, the emplacement of drip shields is feasible with current technology and equipment. A plan for drip shield emplacement was presented using a Drip Shield Transporter, a Drip Shield Emplacement Gantry, a locomotive, and a Drip Shield Gantry Carrier. The use of a Drip Shield Emplacement Gantry as an emplacement concept results in a system that is simple, reliable, and interfaces with the numerous other exising repository systems. Using the Waste Emplacement/Retrieval System design as a basis for the drip shield emplacement concept proved to simplify the system by using existing equipment, such as the gantry carrier, locomotive, Electrical and Control systems, and many other systems, structures, and components. Restricted working envelopes for the Drip Shield Emplacement System require further consideration and must be addressed to show that the emplacement operations can be performed as the repository design evolves. Section 6.1 describes how the Drip Shield Emplacement System may use existing equipment. Depending on the length of time between the conclusion of waste emplacement and the commencement of drip shield emplacement, this equipment could include the locomotives, the gantry carrier, and the electrical, control, and rail systems. If the exisiting equipment is selected for use in the Drip Shield Emplacement System, then the length of time after the final stages of waste emplacement and start of drip shield emplacement may pose a concern for the life cycle of the system (e.g., reliability, maintainability, availability, etc.). Further investigation should be performed to consider the use of existing equipment for drip shield emplacement operations. Further investigation will also be needed regarding the interfaces and heat transfer and thermal effects aspects. The conceptual design also requires further design development. Although the findings of this analysis are accurate for the assumptions made, further refinements of this analysis are needed as the project parameters change. The designs of the drip shield, the Emplacement Drift, and the other drip shield emplacement equipment all have a direct effect on the overall design feasibility.

Silva, R.A.; Cron, J.

2000-03-29T23:59:59.000Z

26

Portable convertible blast effects shield  

DOE Patents [OSTI]

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.

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

27

Portable convertible blast effects shield  

DOE Patents [OSTI]

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.

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

28

Portable convertible blast effects shield  

DOE Patents [OSTI]

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.

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

29

Welding shield for coupling heaters  

DOE Patents [OSTI]

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.

Menotti, James Louis (Dickinson, TX)

2010-03-09T23:59:59.000Z

30

Radiation Shielding and Radiological Protection  

E-Print Network [OSTI]

Radiation Shielding and Radiological Protection J. Kenneth Shultis Richard E. Faw Department@triad.rr.com Radiation Fields and Sources ................................................ . Radiation Field Variables........................................................... .. Direction and Solid Angle Conventions ......................................... .. Radiation Fluence

Shultis, J. Kenneth

31

Thermal neutron shield and method of manufacture  

DOE Patents [OSTI]

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.

Metzger, Bert Clayton; Brindza, Paul Daniel

2014-03-04T23:59:59.000Z

32

Atlas SCT/Pixel Grounding and Shielding ATLAS SCT/Pixel Grounding and Shielding Note  

E-Print Network [OSTI]

Atlas SCT/Pixel Grounding and Shielding 1 ATLAS SCT/Pixel Grounding and Shielding Note November 22 mostly connects existing mechanical electrical conductive #12; Atlas SCT/Pixel Grounding and Shielding 2 that equivalent. The barrel outer heat shield (150 aluminum) main element shield. #12; Atlas SCT/Pixel Grounding

California at Santa Cruz, University of

33

Renormalization plasma shielding effects on scattering entanglement fidelity in dense plasmas  

SciTech Connect (OSTI)

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.

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

34

Radiation shielding materials and containers incorporating same  

DOE Patents [OSTI]

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.

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

2005-11-01T23:59:59.000Z

35

Radiation Shielding Materials and Containers Incorporating Same  

DOE Patents [OSTI]

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.

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

2005-11-01T23:59:59.000Z

36

Penetration seals for TFTR shielding  

SciTech Connect (OSTI)

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.

Hondorp, H.L.

1980-12-01T23:59:59.000Z

37

Shielding and grounding in large detectors  

SciTech Connect (OSTI)

Prevention of electromagnetic interference (EMI), or ``noise pickup,`` is an important design aspect in large detectors in accelerator environments. Shielding effectiveness as a function of shield thickness and conductivity vs the type and frequency of the interference field is described. Noise induced in transmission lines by ground loop driven currents in the shield is evaluated and the importance of low shield resistance is emphasized. Some measures for prevention of ground loops and isolation of detector-readout systems are discussed.

Radeka, V.

1998-09-01T23:59:59.000Z

38

Biological Diversity of the Guiana Shield: Georeferencing Plants of the Guiana Shield  

E-Print Network [OSTI]

of Suriname, maximum elevation 500 m] #12;Georeferencing Plants of the Guiana Shield Google Earth allows

Mathis, Wayne N.

39

Modified shielding jet model for twin-jet shielding analysis  

E-Print Network [OSTI]

the slowing of the jet flow due to turbulent mixing and entrainment of particles from the surrounding medium. The empirical formulations and velocity profiles derived for the respective regions of the jet consider this increase in entrained fluid... velocity profiles are integrated over their respective cross sections of the shielding jet to determine the total volumetric flowrate at the specified locations. A slug flow velocity approximation is then determined for each of the desired downstream...

Gilbride, Jennifer Frances

2012-06-07T23:59:59.000Z

40

Light shield for solar concentrators  

DOE Patents [OSTI]

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.

Plesniak, Adam P.; Martins, Guy L.

2014-08-26T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Hewlett and Duncan - Atomic Shield | Department of Energy  

Office of Environmental Management (EM)

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) " ,"ClickPipelinesProvedDecember 2005DepartmentDecemberGlossaryEnergy and Commerce Subcommittee onDuncan -

42

Shield Volcano | 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 on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov Pty Ltd Jump to: navigation,Pvt Ltd Jump to:Shenzhen79. It.Shida BatteryShield

43

Shielding effectiveness against electromagnetic interference  

SciTech Connect (OSTI)

The use of metal-filled and metal-coated plastics and other modified dielectric materials to replace metals for enclosures has created a need to test these materials for their electromagnetic interference (EMI) shielding effectiveness (SE). Shielding effectiveness involves a variety of electromagnetic environments, and useful data can be obtained from tests that carefully limit the environment to that of a plane wave. Such an environment can be created in a circular or rectangular transmission line. Two such transmission line test fixtures, which hold samples of the material to be tested, have been developed. The fixtures described in this report are the National Bureau of Standards (NBS) coaxial transverse electromagnetic (TEM) cell, and a dual TEM cell constructed at ORNL from a design suggested by the NBS. The NBS coaxial fixture is an improved version of the device recommended by the American Society for Testing and Materials (ASTM). The problems associated with measuring SE are well described in the literature. The two methods described here are the result of years of work to establish procedures and instrumentation that will produce acceptable data.

Googe, J.M.; Hess, R.A.

1987-10-01T23:59:59.000Z

44

Decontaminating lead bricks and shielding  

SciTech Connect (OSTI)

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially of planned decommissioning operations. Thus lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for contaminated lead is removing the superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a scaled-off area. The slurry of abrasive and particles of lead falls through a floor and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling.

Lussiez, G.

1994-02-01T23:59:59.000Z

45

Decontaminating lead bricks and shielding  

SciTech Connect (OSTI)

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium trader pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of contaminated lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling.

Lussiez, G.W.

1993-05-01T23:59:59.000Z

46

Decontaminating lead bricks and shielding  

SciTech Connect (OSTI)

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium trader pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of contaminated lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling.

Lussiez, G.W.

1993-01-01T23:59:59.000Z

47

Thermal neutron shield and method of manufacture  

DOE Patents [OSTI]

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.

Brindza, Paul Daniel; Metzger, Bert Clayton

2013-05-28T23:59:59.000Z

48

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...

49

Study of Active Shielding for {gamma} - Spectrometers  

SciTech Connect (OSTI)

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.

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

50

Hot cell shield plug extraction apparatus  

DOE Patents [OSTI]

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.

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

1995-01-01T23:59:59.000Z

51

Seismic Crystals And Earthquake Shield Application  

E-Print Network [OSTI]

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.

B. Baykant Alagoz; Serkan Alagoz

2009-05-15T23:59:59.000Z

52

Electromagnetic interference shielding using continuous carbon-fiber carbon-matrix and polymer-matrix composites  

E-Print Network [OSTI]

Electromagnetic interference shielding using continuous carbon-fiber carbon-matrix and polymer electromagnetic interference (EMI) shielding material with shielding effectiveness 124 dB, low surface impedance interference shielding 1. Introduction Electromagnetic interference (EMI) shielding is receiv- ing increasing

Chung, Deborah D.L.

53

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

54

Nuclear reactor shield including magnesium oxide  

DOE Patents [OSTI]

An improvement in nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux, the reactor shielding including means providing structural support, neutron moderator material, neutron absorber material and other components as described below, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron.

Rouse, Carl A. (Del Mar, CA); Simnad, Massoud T. (La Jolla, CA)

1981-01-01T23:59:59.000Z

55

Atlas SCT/Pixel Grounding and Shielding Note 1 ATLAS SCT/Pixel Grounding and Shielding Note  

E-Print Network [OSTI]

Atlas SCT/Pixel Grounding and Shielding Note 1 ATLAS SCT/Pixel Grounding and Shielding Note for SCT. This proposal mostly connects existing mechanical and electrical conductive #12;Atlas SCT. The barrel outer heat shield (150 µm aluminum) is the main element of the shield. #12;Atlas SCT

California at Santa Cruz, University of

56

Advancements in FBR shielding - Ten years in Japan  

SciTech Connect (OSTI)

Research and development in the area of fast breeder reactor (FBR) shielding in Japan was fully under way in April 1987 when criticality of the JOYO experimental FBR was first attained. The main activities performed and results obtained during more than 10 yr of FBR shielding research are presented. The paper describes shielding research in Joyo; Monju shielding design and related research; research activities for future FBRs; and evaluation of Monju shielding designs.

Ohtani, Nobuo; Suzuki, Soju

1990-01-01T23:59:59.000Z

57

Space Shielding Materials for Prometheus Application  

SciTech Connect (OSTI)

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.

R. Lewis

2006-01-20T23:59:59.000Z

58

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

E-Print Network [OSTI]

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

Berns, Hans-Gerd

59

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

SciTech Connect (OSTI)

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.

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

1981-12-01T23:59:59.000Z

60

Cosmic Ray Interactions in Shielding Materials  

SciTech Connect (OSTI)

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.

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

2011-09-08T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Vehicle drive module having improved EMI shielding  

DOE Patents [OSTI]

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.

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

2006-11-28T23:59:59.000Z

62

Power converter having improved EMI shielding  

DOE Patents [OSTI]

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.

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

2006-06-13T23:59:59.000Z

63

Thermophysical Properties of Heat Resistant Shielding Material  

SciTech Connect (OSTI)

This project was aimed at determining thermal conductivity, specific heat and thermal expansion of a heat resistant shielding material for neutron absorption applications. These data are critical in predicting the structural integrity of the shielding under thermal cycling and mechanical load. The measurements of thermal conductivity and specific heat were conducted in air at five different temperatures (-31 F, 73.4 F, 140 F, 212 F and 302 F). The transient plane source (TPS) method was used in the tests. Thermal expansion tests were conducted using push rod dilatometry over the continuous range from -40 F (-40 C) to 302 F (150 C).

Porter, W.D.

2004-12-15T23:59:59.000Z

64

Oxygen Abundance Measurements of SHIELD Galaxies  

E-Print Network [OSTI]

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...

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

2015-01-01T23:59:59.000Z

65

Beer and Economic Growth Dr. Martin Shields  

E-Print Network [OSTI]

Beer and Economic Growth Dr. Martin Shields Regional Economics Institute Colorado State University #12;The Idea · Regional economic growth depends, in part, on the ability to sell goods and services) ­ Industry employment is 35 times more concentrated in Larimer County than the US average! #12;Economic

66

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 Experimental Test of Self-Shielding in VUV Photodissociation of CO Print Wednesday, 25 March 2009 00:00 One way...

67

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

SciTech Connect (OSTI)

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.

Johnson, William C.; Shokair, Isaac R.

2011-12-01T23:59:59.000Z

68

Effective shielding to measure beam current from an ion source  

SciTech Connect (OSTI)

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.

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

69

Engineering of Ferrite-Graphite Composite Media for Microwave Shields  

E-Print Network [OSTI]

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

Koledintseva, Marina Y.

70

Hadronic Atoms  

E-Print Network [OSTI]

We review the theory of hadronic atoms in QCD+QED. The non-relativistic effective Lagrangian approach, used to describe this type of bound states, is illustrated with the case of pi+pi- atoms. In addition, we discuss the evaluation of isospin-breaking corrections to hadronic atom observables by invoking chiral perturbation theory.

J. Gasser; V. E. Lyubovitskij; A. Rusetsky

2009-03-02T23:59:59.000Z

71

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

SciTech Connect (OSTI)

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.

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

72

Thermoforming plastic in lead shield construction  

SciTech Connect (OSTI)

Radiation treatments using low energy X-rays or electrons frequently require a final field defining shield to be placed on the patient's skin. A custom made lead cut-out is used to provide a close fit to a particular patient's surface contours. We have developed a procedure which utilizes POLYFORM thermoplastic to obtain a negative mold of the patient instead of the traditional plaster bandage or dental impression gel. The Polyform is softened in warm water, molded carefully over the patient's surface, and is removed when set or hardened, usually within five minutes. Then lead sheet cut-outs can be formed within this negative. For shielding cut-outs requiring thicker lead sheet, a positive is made from dental stone using this Polyform negative. We have found this procedure to be neat, fast and comfortable for both patient and the dosimetrist.

Abrahams, M.E.; Chow, C.H.; Loyd, M.D. (Univ. of Texas Medical Branch, Galveston (USA))

1989-09-01T23:59:59.000Z

73

Electronically shielded solid state charged particle detector  

DOE Patents [OSTI]

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.

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

1996-08-20T23:59:59.000Z

74

Electronically shielded solid state charged particle detector  

DOE Patents [OSTI]

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.

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

75

Supplemental heating of deposition tooling shields  

DOE Patents [OSTI]

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.

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

76

Transparent self-cleaning dust shield  

DOE Patents [OSTI]

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.

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

2005-06-28T23:59:59.000Z

77

GRAVITATIONAL FIELD SHIELDING AND SUPERNOVA EXPLOSIONS  

SciTech Connect (OSTI)

A new mechanism for supernova explosions called gravitational field shielding is proposed, in accord with a five-dimensional fully covariant Kaluza-Klein theory with a scalar field that unifies the four-dimensional Einsteinian general relativity and Maxwellian electromagnetic theory. It is shown that a dense compact collapsing core of a star will suddenly turn off or completely shield its gravitational field when the core collapses to a critical density, which is inversely proportional to the square of mass of the core. As the core suddenly turns off its gravity, the extremely large pressure immediately stops the core collapse and pushes the mantle material of supernova moving outward. The work done by the pressure in the expansion can be the order of energy released in a supernova explosion. The gravity will resume and stop the core from a further expansion when the core density becomes less than the critical density. Therefore, the gravitational field shielding leads a supernova to impulsively explode and form a compact object such as a neutron star as a remnant. It works such that a compressed spring will shoot the oscillator out when the compressed force is suddenly removed.

Zhang, T. X. [Physics Department, Alabama A and M University, Normal, AL 35762 (United States)

2010-12-20T23:59:59.000Z

78

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

79

Cross Section Evaluation Group shielding benchmark compilation. Volume II  

SciTech Connect (OSTI)

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.

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

1983-12-01T23:59:59.000Z

80

Radiation shielding for underground low-background experiments  

E-Print Network [OSTI]

The design task of creating an efficient radiation shield for the new COBRA double-beta decay experiment led to a comprehensive study of commercially available shielding materials. The aim was to find the most efficient combination of materials under the constraints of an extreme low-background experiment operating in a typical underground laboratory. All existing shield configurations for this type of experiment have been found to perform sub-optimally in comparison to the class of multilayered configurations proposed in this study. The method used here to create a specific shield configuration should yield a close to optimal result when applied to any experiment utilising a radiation shield. In particular, the survey of single material response to a given radiation source turns out to give a guideline for the construction of efficient multilayer shields.

D. Y Stewart; P. F. Harrison; B. Morgan; Y. A. Ramachers

2006-07-31T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

SciTech Connect (OSTI)

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.

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

2011-02-01T23:59:59.000Z

82

Shielded serpentine traveling wave tube deflection structure  

DOE Patents [OSTI]

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).

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

1994-01-01T23:59:59.000Z

83

Longwall shield design: is bigger better?  

SciTech Connect (OSTI)

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.

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

2008-05-15T23:59:59.000Z

84

X-ray transmissive debris shield  

DOE Patents [OSTI]

An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

Spielman, Rick B. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

85

Methods and Procedures for Shielding Analyses for the SNS  

SciTech Connect (OSTI)

In order to provide radiologically safe Spallation Neutron Source operation, shielding analyses are performed according to Oak Ridge National Laboratory internal regulations and to comply with the Code of Federal Regulations. An overview of on-going shielding work for the accelerator facility and neutrons beam lines, methods, used for the analyses, and associated procedures and regulations is presented. Methods used to perform shielding analyses are described as well.

Gallmeier, Franz X [ORNL] [ORNL; Iverson, Erik B [ORNL] [ORNL; Remec, Igor [ORNL] [ORNL; Lu, Wei [ORNL] [ORNL; Popova, Irina [ORNL] [ORNL

2014-01-01T23:59:59.000Z

86

Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon  

E-Print Network [OSTI]

Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon Nanotube Epoxy Composites Ning (SWNT)-polymer composites have been fabricated to evaluate the electromagnetic interference (EMI

Gao, Hongjun

87

Gravity Scaling of a Power Reactor Water Shield  

SciTech Connect (OSTI)

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.

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

2008-01-21T23:59:59.000Z

88

Graphene shield enhanced photocathodes and methods for making the same  

SciTech Connect (OSTI)

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.

Moody, Nathan Andrew

2014-09-02T23:59:59.000Z

89

MicroShield/ISOCS gamma modeling comparison.  

SciTech Connect (OSTI)

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.

Sansone, Kenneth R

2013-08-01T23:59:59.000Z

90

SHIELDING ANALYSIS FOR PORTABLE GAUGING COMBINATION SOURCES  

SciTech Connect (OSTI)

Radioisotopic decay has been used as a source of photons and neutrons for industrial gauging operations since the late 1950s. Early portable moisture/density gauging equipment used Americium (Am)-241/Beryllium (Be)/Cesium (Cs)-137 combination sources to supply the required nuclear energy for gauging. Combination sources typically contained 0.040 Ci of Am-241 and 0.010 Ci of CS-137 in the same source capsule. Most of these sources were manufactured approximately 30 years ago. Collection, transportation, and storage of these sources once removed from their original device represent a shielding problem with distinct gamma and neutron components. The Off-Site Source Recovery (OSR) Project is planning to use a multi-function drum (MFD) for the collection, shipping, and storage of AmBe sources, as well as the eventual waste package for disposal. The MFD is an approved TRU waste container design for DOE TRU waste known as the 12 inch Pipe Component Overpack. As the name indicates, this drum is based on a 12 inch ID stainless steel weldment approximately 25 inch in internal length. The existing drum design allows for addition of shielding within the pipe component up to the 110 kg maximum pay load weight. The 12 inch pipe component is packaged inside a 55-gallon drum, with the balance of the interior space filled with fiberboard dunnage. This packaging geometry is similar to the design of a DOT 6M, Type B shipping container.

J. TOMPKINS; L. LEONARD; ET AL

2000-08-01T23:59:59.000Z

91

System for imaging plutonium through heavy shielding  

SciTech Connect (OSTI)

A single pinhole can be used to image strong self-luminescent gamma-ray sources such as plutonium on gamma scintillation (Anger) cameras. However, if the source is weak or heavily shielded, a poor signal to noise ratio can prevent acquisition of the image. An imaging system designed and built at Los Alamos National Laboratory uses a coded aperture to image heavily shielded sources. The paper summarizes the mathematical techniques, based on the Fast Delta Hadamard transform, used to decode raw images. Practical design considerations such as the phase of the uniformly redundant aperture and the encoded image sampling are discussed. The imaging system consists of a custom designed m-sequence coded aperture, a Picker International Corporation gamma scintillation camera, a LeCroy 3500 data acquisition system, and custom imaging software. The paper considers two sources - 1.5 mCi /sup 57/Co unshielded at a distance of 27 m and 220 g of bulk plutonium (11.8% /sup 240/Pu) with 0.3 cm lead, 2.5 cm steel, and 10 cm of dense plastic material at a distance of 77.5 cm. Results show that the location and geometry of a source hidden in a large sealed package can be determined without having to open the package. 6 references, 4 figures.

Kuckertz, T.H.; Cannon, T.M.; Fenimore, E.E.; Moss, C.E.; Nixon, K.V.

1984-04-01T23:59:59.000Z

92

Liquid Vortex Shielding for Fusion Energy Applications  

SciTech Connect (OSTI)

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.

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

93

General Corrosion and Localized Corrosion of the Drip Shield  

SciTech Connect (OSTI)

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]).

F. Hua

2004-09-16T23:59:59.000Z

94

Issues and test requirements in radiation shielding of fusion reactors  

SciTech Connect (OSTI)

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.

Nakagawa, M.; Abdou, M.A.

1986-11-01T23:59:59.000Z

95

Issues and test requirements in radiation shielding of fusion reactors  

SciTech Connect (OSTI)

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.

Nakagawa, M.; Abdou, M.A.

1986-01-01T23:59:59.000Z

96

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

SciTech Connect (OSTI)

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.

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

97

Fan-fold shielded electrical leads  

DOE Patents [OSTI]

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.

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

1996-06-11T23:59:59.000Z

98

Fan-fold shielded electrical leads  

DOE Patents [OSTI]

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.

Rohatgi, Rajeev R. (Mountain View, CA); Cowan, Thomas E. (Livermore, CA)

1996-01-01T23:59:59.000Z

99

Protective shield for an instrument probe  

DOE Patents [OSTI]

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.

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

2004-10-26T23:59:59.000Z

100

E-Print Network 3.0 - analytical shielding calculations Sample...  

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

Use of Magnetic and Electrically Conductive Fillers in a Polymer Matrix for Electromagnetic Interference Shielding Summary: for Electromagnetic Interference Shielding JUNHUA WU1,2...

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Polyethylene as a Radiation Shielding Standard in Simulated Cosmic-Ray Environments  

E-Print Network [OSTI]

on the ISS through polyethylene shielding augmentation ofnucleon Iron-56 in Polyethylene. II. , Comparisons betweenPolyethylene as a Radiation Shielding Standard in Simulated

2006-01-01T23:59:59.000Z

102

RELATIVE ATTENUATION CHARACTERISTICS OF SOME SHIELDING MATERIALS FOR PuB NEUTRONS  

E-Print Network [OSTI]

1: Polyethylene Water Spodumene-gypsum Gypsum, wet and dryconstituents of the spodumene-gypsum, and gypsum shields.SPODUMENK·,GYPSUM SHIELD 30% Spodumene by weight 40% Gypsum

Bringham, P.S.

2010-01-01T23:59:59.000Z

103

Atom Interferometry  

ScienceCinema (OSTI)

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?

Mark Kasevich

2010-01-08T23:59:59.000Z

104

Shielding design for the proposed Advanced Photon Source at Argonne  

SciTech Connect (OSTI)

Bulk shielding was designed for the proposed Argonne Advanced Photon Source. The shielding is for two linacs, the positron converter, booster synchrotron, and the storage ring. Shielding design limits exposure to 20 mrem/wk for occupational and 25 mrem/y for an individual member of the public from the radiation products, which include high energy neutrons (HEN), giant resonance neutrons (GRN), and Bremsstrahlung radiation (BR). The beam loss parameters at various components were estimated. Dose rates were computed for continuous loss during beam decay using an empirical method. Normal operational losses and certain accidental beam losses were also considered.

Moe, H.J.; Veluri, V.R.

1987-01-01T23:59:59.000Z

105

Radiolysis Concerns for Water Shielding in Fission Surface Power Applications  

SciTech Connect (OSTI)

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.

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

106

Electric field shielding in dielectric nanosolutions  

E-Print Network [OSTI]

To gain some insight into electrochemical activity of dielectric colloids of technical and biomedical interest we investigate a model of dielectric nanosolution whose micro-constitution is dominated by dipolarions -- positively and negatively charged spherically symmetric nano-structures composed of ionic charge surrounded by cloud of radially polarized dipoles of electrically neutral molecules of solvent. Combing the standard constitutive equations of an isotropic dielectric liquid with Maxwell equation of electrostatics and presuming the Boltzmann shape of the particle density of bound-charge we derive equation for the in-medium electrostatic field. Particular attention is given to numerical analysis of obtained analytic solutions of this equation describing the exterior fields of dipolarions with dipolar atmospheres of solvent molecules endowed with either permanent or field-induced dipole moments radially polarized by central symmetric field of counterions. The presented computations show that the electric field shielding of dipolarions in dielectric nanosolutions is quite different from that of counterionic nano-complexes of Debye-H\\"uckel theory of electrolytes.

Sergey Bastrukov; Pik-Yin Lai; Irina Molodtsova

2014-03-26T23:59:59.000Z

107

Addendum to NuMI shielding assessment  

SciTech Connect (OSTI)

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.

Vaziri, Kamran; /Fermilab

2007-10-01T23:59:59.000Z

108

Method for the construction of x-ray shielding masks  

SciTech Connect (OSTI)

A method is described for the production of a rigid model of a patient's face onto which lead shielding sheets may be contoured. The model is cast in Lipowitz's metal using a plaster mold.

Canup, D.; Ekstrand, K.E.

1982-03-01T23:59:59.000Z

109

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

110

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...

111

RSMASS: A simple model for estimating reactor and shield masses  

SciTech Connect (OSTI)

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.

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

1987-01-01T23:59:59.000Z

112

Upgrade of the LHC magnet interconnections thermal shielding  

SciTech Connect (OSTI)

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.

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

113

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]

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

Aalberts, Daniel P.

114

Atomic magnetometer  

DOE Patents [OSTI]

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.

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

2012-07-03T23:59:59.000Z

115

Shielded fluid stream injector for particle bed reactor  

DOE Patents [OSTI]

A shielded fluid-stream injector assembly is provided for particle bed reactors. The assembly includes a perforated pipe injector disposed across the particle bed region of the reactor and an inverted V-shaped shield placed over the pipe, overlapping it to prevent descending particles from coming into direct contact with the pipe. The pipe and shield are fixedly secured at one end to the reactor wall and slidably secured at the other end to compensate for thermal expansion. An axially extending housing aligned with the pipe and outside the reactor and an in-line reamer are provided for removing deposits from the inside of the pipe. The assembly enables fluid streams to be injected and distributed uniformly into the particle bed with minimized clogging of injector ports. The same design may also be used for extraction of fluid streams from particle bed reactors.

Notestein, John E. (Morgantown, WV)

1993-01-01T23:59:59.000Z

116

Shielding analysis of the NAC-MPC storage system  

SciTech Connect (OSTI)

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.

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

117

AXIAL SOURCE PROFILE EFFECT ON WASTE PACKAGE TRANSPORTER SHIELDING  

SciTech Connect (OSTI)

The purpose of this scoping calculation is to support preliminary design of the Waste Package (WP) transporter radiation shield configuration. Spent Nuclear Fuel (SNF) is highly radioactive and site personnel must be protected during the period that the WPs are emplaced. Personnel protection is accomplished via a heavily shielded WP transporter that moves the waste from the surface to the emplacement drift. All previous WP transporter shielding calculations have assumed a Design Basis Fuel (DBF) in which the fuel burnup is uniform (e.g. Ref. 7.3, Ref. 7.4, and Ref. 7.12). In reality, SNF burnup varies significantly from one end of the fuel assembly to the other. Since source strengths are dependent upon fuel burnup, a model which varies the fuel burnup along the assembly axis will produce a more accurate depiction of the radiation field surrounding the WP transporter. The objective of this calculation is to determine the need for using the actual axial profile, as opposed to the uniform burnup assumption, in the WP transporter shield design. The scope of the calculation is as follows: (1) Determine the impact of axial source term variation on WP transporter contact dose rates. (2) Determine appropriate shielding modifications to account for expected dose rate peaking effects. Consistent with the previous subsurface shielding analyses, this calculation considers the bounding 21 Pressurized Water Reactor (PWR) WP only. The calculation will need to be revised and extended to Boiling Water Reactor (BWR) SNF upon selection of the WP design for the License Application (LA) and availability of the source terms from the WP Operations Group.

A. Nielsen

1999-06-30T23:59:59.000Z

118

Renormalization shielding and eikonal analysis on the atomic collision in dense partially ionized hydrogen plasmas  

SciTech Connect (OSTI)

The renormalization plasma screening effects on the electron-ion collision are investigated in dense partially ionized hydrogen plasmas. The Hamilton-Jacobi and eikonal methods with the effective interaction potential are employed to obtain the eikonal scattering phase shift and eikonal cross section for the electron-ion collision. It is found that the influence of renormalization screening strongly suppresses the eikonal scattering phase shift as well as the eikonal cross section, especially, for small impact parameter regions. In addition, the renormalization screening effect reduces the total eikonal cross section in all energy domains. The variation of the renormalization effects on the electron-ion collision in dense partially ionized hydrogen plasmas is also discussed.

Kim, Sung Soo [Department of Applied Mathematics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of)] [Department of Applied Mathematics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Jung, Young-Dae [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of) [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180-3590 (United States)

2013-12-15T23:59:59.000Z

119

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...

120

A Note on Hamilton Cycles in Kneser Graphs Ian Shields  

E-Print Network [OSTI]

A Note on Hamilton Cycles in Kneser Graphs Ian Shields IBM P.O. Box 12195 Research Triangle Park) have Hamilton cycles when n #20; 27. A similar result is shown for bipartite Kneser graphs. 1 for Hamilton cycles in Kneser graphs, K(n; k), and bipartite Kneser graphs, H(n; k). With the exception

Savage, Carla D.

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

RSMASS-D: Reactor and shield mass minimization models  

SciTech Connect (OSTI)

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.

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

122

February, 2010 Fire Analysis of the Shielded Container  

E-Print Network [OSTI]

Pilot Plant Carlsbad, New Mexico Preparer: Independent Technical Review: Ray Sprankle RSL Safety;FIRE ANALYSIS OF THE SHIELDED CONTAINER FOR THE WIPP-032, REV. 0 WASTE ISOLATION PILOT PLANT, CARLSBAD, CARLSBAD, NEW MEXICO PAGE 3 OF 28 Executive Summary Transuranic waste is currently shipped to the WIPP from

123

RZ calculations for self shielded multigroup cross sections  

SciTech Connect (OSTI)

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)

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

124

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

E-Print Network [OSTI]

PERGAMON Carbon 39 (2001) 279­285 Review Electromagnetic interference shielding effectiveness materials for electromagnetic interference (EMI) shielding are reviewed. They include composite materials-structural and structural composites, colloi- dal graphite, as well as EMI gasket materials. Electromagnetic interference

Chung, Deborah D.L.

125

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

SciTech Connect (OSTI)

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.

Koji Shirai

2006-04-01T23:59:59.000Z

126

Accelerator shield design of KIPT neutron source facility  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of a neutron source facility at KIPT utilizing an electron-accelerator-driven subcritical assembly. Electron beam power is 100 kW, using 100 MeV electrons. The facility is designed to perform basic and applied nuclear research, produce medical isotopes, and train young nuclear specialists. The biological shield of the accelerator building is designed to reduce the biological dose to less than 0.5-mrem/hr during operation. The main source of the biological dose is the photons and the neutrons generated by interactions of leaked electrons from the electron gun and accelerator sections with the surrounding concrete and accelerator materials. The Monte Carlo code MCNPX serves as the calculation tool for the shield design, due to its capability to transport electrons, photons, and neutrons coupled problems. The direct photon dose can be tallied by MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is less than 0.01 neutron per electron. This causes difficulties for Monte Carlo analyses and consumes tremendous computation time for tallying with acceptable statistics the neutron dose outside the shield boundary. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were developed for the study. The generated neutrons are banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron and secondary photon doses. The weight windows variance reduction technique is utilized for both neutron and photon dose calculations. Two shielding materials, i.e., heavy concrete and ordinary concrete, were considered for the shield design. The main goal is to maintain the total dose outside the shield boundary at less than 0.5-mrem/hr. The shield configuration and parameters of the accelerator building have been determined and are presented in this paper. (authors)

Zhong, Z.; Gohar, Y. [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)

2013-07-01T23:59:59.000Z

127

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

E-Print Network [OSTI]

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

Romalis, Mike

128

Electromagnetic interference shielding reaching 70 dB in steel fiber cement  

E-Print Network [OSTI]

Electromagnetic interference shielding reaching 70 dB in steel fiber cement Sihai Wen, D.D.L. Chung; Silica fume; Shielding 1. Introduction Electromagnetic interference (EMI) shielding [1­4] is in critical, NY 14260-4400, USA Received 9 January 2002; accepted 14 August 2003 Abstract An electromagnetic

Chung, Deborah D.L.

129

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

E-Print Network [OSTI]

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

Ravikumar, B.

130

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

E-Print Network [OSTI]

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

New Hampshire, University of

131

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

132

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

133

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

E-Print Network [OSTI]

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

Demouchy, Sylvie

134

Field corrosion testing and performance of cable shielding materials in soils  

SciTech Connect (OSTI)

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.

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

135

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...

136

Superconducting shielded core reactor with reduced AC losses  

DOE Patents [OSTI]

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.

Cha, Yung S.; Hull, John R.

2006-04-04T23:59:59.000Z

137

CORROSION OF LEAD SHIELDING IN NUCLEAR MATERIALS PACKAGES  

SciTech Connect (OSTI)

Inspection of United States-Department of Energy (US-DOE) model 9975 nuclear materials shipping package revealed corrosion of the lead shielding that was induced by off-gas constituents from organic components in the package. Experiments were performed to determine the corrosion rate of lead when exposed to off-gas or degradation products of these organic materials. The results showed that the room temperature vulcanizing (RTV) sealant was the most corrosive organic species used in the construction of the packaging, followed by polyvinyl acetate (PVAc) glue. Fiberboard material, also used in the construction of the packaging induced corrosion to a much lesser extent than the PVAc glue and RTV sealant, and only in the presence of condensed water. The results indicated faster corrosion at temperatures higher than ambient and with condensed water. In light of these corrosion mechanisms, the lead shielding was sheathed in a stainless steel liner to mitigate against corrosion.

Subramanian, K; Kerry Dunn, K; Joseph Murphy, J

2008-07-18T23:59:59.000Z

138

Theoretical prediction of nuclear magnetic shieldings and indirect spin-spin coupling constants in 1,1-, cis-, and trans-1,2-difluoroethylenes  

SciTech Connect (OSTI)

A theoretical prediction of nuclear magnetic shieldings and indirect spin-spin coupling constants in 1,1-, cis- and trans-1,2-difluoroethylenes is reported. The results obtained using density functional theory (DFT) combined with large basis sets and gauge-independent atomic orbital calculations were critically compared with experiment and conventional, higher level correlated electronic structure methods. Accurate structural, vibrational, and NMR parameters of difluoroethylenes were obtained using several density functionals combined with dedicated basis sets. B3LYP/6-311++G(3df,2pd) optimized structures of difluoroethylenes closely reproduced experimental geometries and earlier reported benchmark coupled cluster results, while BLYP/6-311++G(3df,2pd) produced accurate harmonic vibrational frequencies. The most accurate vibrations were obtained using B3LYP/6-311++G(3df,2pd) with correction for anharmonicity. Becke half and half (BHandH) density functional predicted more accurate {sup 19}F isotropic shieldings and van Voorhis and Scuseria's ?-dependent gradient-corrected correlation functional yielded better carbon shieldings than B3LYP. A surprisingly good performance of Hartree-Fock (HF) method in predicting nuclear shieldings in these molecules was observed. Inclusion of zero-point vibrational correction markedly improved agreement with experiment for nuclear shieldings calculated by HF, MP2, CCSD, and CCSD(T) methods but worsened the DFT results. The threefold improvement in accuracy when predicting {sup 2}J(FF) in 1,1-difluoroethylene for BHandH density functional compared to B3LYP was observed (the deviations from experiment were ?46 vs. ?115 Hz)

Nozirov, Farhod, E-mail: teobaldk@gmail.com, E-mail: farhod.nozirov@gmail.com [Department of Physics, 4513 Manhattan College Parkway Riverdale, New York 10471 (United States)] [Department of Physics, 4513 Manhattan College Parkway Riverdale, New York 10471 (United States); Stachów, Micha?, E-mail: michal.stachow@gmail.com [Faculty of Chemistry, Opole University, 48, Oleska Street, 45-052 Opole (Poland)] [Faculty of Chemistry, Opole University, 48, Oleska Street, 45-052 Opole (Poland); Kupka, Teobald, E-mail: teobaldk@gmail.com, E-mail: farhod.nozirov@gmail.com

2014-04-14T23:59:59.000Z

139

Attenuation of high-energy x rays by iron shielding  

SciTech Connect (OSTI)

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.

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

1988-04-01T23:59:59.000Z

140

Neutral atom traps.  

SciTech Connect (OSTI)

This report describes progress in designing a neutral atom trap capable of trapping sub millikelvin atom in a magnetic trap and shuttling the atoms across the atom chip from a collection area to an optical cavity. The numerical simulation and atom chip design are discussed. Also, discussed are preliminary calculations of quantum noise sources in Kerr nonlinear optics measurements based on electromagnetically induced transparency. These types of measurements may be important for quantum nondemolition measurements at the few photon limit.

Pack, Michael Vern

2008-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

ACCURATE TEMPERATURE MEASUREMENTS IN A NATURALLY-ASPIRATED RADIATION SHIELD  

SciTech Connect (OSTI)

Experiments and calculations were conducted with a 0.13 mm fine wire thermocouple within a naturally-aspirated Gill radiation shield to assess and improve the accuracy of air temperature measurements without the use of mechanical aspiration, wind speed or radiation measurements. It was found that this thermocouple measured the air temperature with root-mean-square errors of 0.35 K within the Gill shield without correction. A linear temperature correction was evaluated based on the difference between the interior plate and thermocouple temperatures. This correction was found to be relatively insensitive to shield design and yielded an error of 0.16 K for combined day and night observations. The correction was reliable in the daytime when the wind speed usually exceeds 1 m s{sup -1} but occasionally performed poorly at night during very light winds. Inspection of the standard deviation in the thermocouple wire temperature identified these periods but did not unambiguously locate the most serious events. However, estimates of sensor accuracy during these periods is complicated by the much larger sampling volume of the mechanically-aspirated sensor compared with the naturally-aspirated sensor and the presence of significant near surface temperature gradients. The root-mean-square errors therefore are upper limits to the aspiration error since they include intrinsic sensor differences and intermittent volume sampling differences.

Kurzeja, R.

2009-09-09T23:59:59.000Z

142

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]

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

Ronquist, Fredrik

143

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

SciTech Connect (OSTI)

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.

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

144

WAPDEG Analysis of Waste Package and Drip shield Degradation  

SciTech Connect (OSTI)

As directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), an analysis of the degradation of the engineered barrier system (EBS) drip shields and waste packages at the Yucca Mountain repository is developed. The purpose of this activity is to provide the TSPA with inputs and methodologies used to evaluate waste package and drip shield degradation as a function of exposure time under exposure conditions anticipated in the repository. This analysis provides information useful to satisfy ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]) requirements. Several features, events, and processes (FEPs) are also discussed (Section 6.2, Table 15). The previous revision of this report was prepared as a model report in accordance with AP-SIII.10Q, Models. Due to changes in the role of this report since the site recommendation, it no longer contains model development. This revision is prepared as a scientific analysis in accordance with AP-SIII.9Q, ''Scientific Analyses'' and uses models previously validated in (1) ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]); (2) ''General Corrosion and Localized Corrosion of Waste Package Outer Barrier'' (BSC 2004 [DIRS 169984]); and (3) ''General Corrosion and Localized Corrosion of Drip Shield'' (BSC 2004 [DIRS 169845]). The integrated waste package degradation (IWPD) analysis presented in this report treats several implementation-related issues, such as defining the number and size of patches per waste package that undergo stress corrosion cracking; recasting the weld flaw analysis in a form as implemented in the Closure Weld Defects (CWD) software; and, general corrosion rate manipulations (e.g., change of scale in Section 6.3.4). The weld flaw portion of this report takes input from an engineering calculation (BSC 2004 [DIRS 170024]) and uses standard mathematical methods to enable easier implementation. The IWPD analysis also provides guidance on implementation of early failures (importance sampling and multinomial distribution usage). These manipulations are evident from standard scientific practices, approaches, or methods and do not require changes to the previously validated models. The IWPD analysis itself (Section 6.4), not the resultant curves from executing the IWPD analysis presented in Section 6.5 (which are for illustrative purposes), is used directly in total system performance assessment (TSPA). The IWPD analysis simulates general corrosion and stress corrosion cracking of the waste package outer barrier and general corrosion of the drip shield. The effects of igneous and seismic events and localized corrosion on drip shield and waste package performance are not evaluated in this report. The outputs of this report are inputs and methodologies used by TSPA to evaluate waste package and drip shield degradation as a function of exposure time under exposure conditions anticipated in the repository. The analyses presented in this report are for the current repository design (BSC 2004 [DIRS 168489]).

K. Mon

2004-09-29T23:59:59.000Z

145

7 -ATOMIC PROCESSES Atomic processes can be  

E-Print Network [OSTI]

1 7 - ATOMIC PROCESSES Atomic processes can be: 1. Scattering 2. Absorption/Thermal Emission scattering, although the results won't change much when this condition is relaxed. Absorption/Thermal Emission Free-free (continuum) ("Bremsstrahlung") Emission/Absorption #12;2 Bound-Bound & Bound

Sitko, Michael L.

146

7 -ATOMIC PROCESSES Atomic processes can be  

E-Print Network [OSTI]

1 7 - ATOMIC PROCESSES Atomic processes can be: 1. Scattering 2. Absorption/Thermal Emission scattering, although the results won't change much when this condition is relaxed. #12;2 Absorption/Thermal Emission Free-free (continuum) ("Bremsstrahlung") Emission/Absorption Bound-Bound & Bound-Free Processes

Sitko, Michael L.

147

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)

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.

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

2011-10-01T23:59:59.000Z

148

Atomizing nozzle and process  

DOE Patents [OSTI]

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.

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

1993-07-20T23:59:59.000Z

149

Early Test Facilities and Analytic Methods for Radiation Shielding  

SciTech Connect (OSTI)

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.

Ingersoll, D.T.

1992-01-01T23:59:59.000Z

150

Dose estimates in a loss of lead shielding truck accident.  

SciTech Connect (OSTI)

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.

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

2009-08-01T23:59:59.000Z

151

Reflector and Shield Material Properties for Project Prometheus  

SciTech Connect (OSTI)

This letter provides updated reflector and shield preliminary material property information to support reactor design efforts. The information provided herein supersedes the applicable portions of Revision 1 to the Space Power Program Preliminary Reactor Design Basis (Reference (a)). This letter partially answers the request in Reference (b) to provide unirradiated and irradiated material properties for beryllium, beryllium oxide, isotopically enriched boron carbide ({sup 11}B{sub 4}C) and lithium hydride. With the exception of {sup 11}B{sub 4}C, the information is provided in Attachments 1 and 2. At the time of issuance of this document, {sup 11}B{sub 4}C had not been studied.

J. Nash

2005-11-02T23:59:59.000Z

152

Submicron carbon filament cement-matrix composites for electromagnetic interference shielding  

SciTech Connect (OSTI)

Carbon filaments of diameter 0.1 mm were found to be a much more effective additive than conventional carbon fibers of diameter 10 mm in providing cement pastes capable of electromagnetic interference shielding. With 0.54 vol. % filaments and a shield thickness of 4 mm, a shielding effectiveness of 30 dB was attained at 1--2 GHz. However, the filaments were less effective than the fibers for reinforcing and for providing strain sensing cement-matrix composites.

Fu, X.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.] [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.

1996-10-01T23:59:59.000Z

153

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

154

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

SciTech Connect (OSTI)

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.

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

2009-07-01T23:59:59.000Z

155

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

SciTech Connect (OSTI)

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.

Sindelar, R.L.

1999-10-21T23:59:59.000Z

156

E-Print Network 3.0 - aircraft shield test reactor Sample Search...  

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

Collection: Plasma Physics and Fusion 50 PERGAMON Carbon 39 (2001) 279285 Electromagnetic interference shielding effectiveness of carbon Summary: -matrix structural composites...

157

E-Print Network 3.0 - advanced shielding systems Sample Search...  

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

Computer Engineering, University of Rochester Collection: Engineering 77 Electromagnetic interference shielding using continuous carbon-fiber carbon-matrix and polymer-matrix...

158

1. Shielding against Electromagnetic Interference With telecommunication networks connecting wireless devices around the globe, there  

E-Print Network [OSTI]

#12;1. Shielding against Electromagnetic Interference With telecommunication networks connecting electromagnetic interference (EMI) across the airwaves. These communication networks are ubiquitous and dynamic

Rincon-Mora, Gabriel A.

159

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

SciTech Connect (OSTI)

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.

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

160

Nitrogen containing shielding gases for GTAW duplex stainless steels  

SciTech Connect (OSTI)

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.

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

1993-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

E-Print Network [OSTI]

for Electromagnetic Interference Shielding JUNHUA WU1,2 and D.D.L. CHUNG1,3 1.--Composite Materials Research for electromagnetic interference shielding than the use of a highly magnetic filler alone or the use of a highly, magnetic, electrical resistivity, nickel, mumetal, graphite INTRODUCTION Electromagnetic interference (EMI

Chung, Deborah D.L.

162

The influence of single-walled carbon nanotube structure on the electromagnetic interference shielding  

E-Print Network [OSTI]

The influence of single-walled carbon nanotube structure on the electromagnetic interference.01­15%) have been evaluated for electromagnetic interference (EMI) shielding effectiveness (SE) in the X and aerospace sectors with uses such as electrostatic dissipation, electromagnetic interference (EMI) shielding

Gao, Hongjun

163

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

E-Print Network [OSTI]

Shielding-Effectiveness Modeling of Carbon-Fiber/Nylon- 6,6 Composites Nicholas B. Janda,1 Jason M for various amounts of Thermal- Graph DKD X carbon fiber within nylon 6,6. The theory predicts that the most important parameters for the shield- ing effectiveness of a sample are the carbon-fiber volume percentage

Perger, Warren F.

164

Value Creation with Dye's Disclosure Option: Optimal Risk-Shielding with an Upper Tailed Disclosure Strategy  

E-Print Network [OSTI]

Value Creation with Dye's Disclosure Option: Optimal Risk-Shielding with an Upper Tailed DisclosureRiskShielding-CDAM.tex CDAM Research Report LSE-CDAM-2007-30 Abstract Dye (1985) showed that the optimal disclosure policy¤ level, we value the corresponding option using contingent claims analysis. It is shown that the Dye

Haase, Markus

165

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

E-Print Network [OSTI]

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

Helgaker, Trygve

166

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

167

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

SciTech Connect (OSTI)

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.

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

2012-10-01T23:59:59.000Z

168

Overlap Technique for End-Cap Seals on Cylindrical Magnetic Shields  

E-Print Network [OSTI]

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.

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

2013-01-01T23:59:59.000Z

169

Multiplicative Sets of Atoms.  

E-Print Network [OSTI]

??It is possible for an element to have both an atom factorization and a factorization that will always contain a reducible element. This leads us… (more)

Rand, Ashley Nicole

2013-01-01T23:59:59.000Z

170

Improved graphite furnace atomizer  

DOE Patents [OSTI]

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.

Siemer, D.D.

1983-05-18T23:59:59.000Z

171

Atomic Collapse Observed  

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

and professor of Physics at UC Berkeley. Nonrelativistic electrons orbiting a subcritical nucleus exhibit the traditional circular Bohr orbit of atomic physics. But when the...

172

U. S. ITER shield and blanket design activities  

SciTech Connect (OSTI)

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/.

Baker, C.C.

1989-03-01T23:59:59.000Z

173

Method for fabricating fan-fold shielded electrical leads  

DOE Patents [OSTI]

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.

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

1994-12-27T23:59:59.000Z

174

Method for fabricating fan-fold shielded electrical leads  

DOE Patents [OSTI]

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.

Rohatgi, Rajeev R. (Mountain View, CA); Cowan, Thomas E. (Livermore, CA)

1994-01-01T23:59:59.000Z

175

Underground barrier construction apparatus with soil-retaining shield  

DOE Patents [OSTI]

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.

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

176

Underground barrier construction apparatus with soil-retaining shield  

DOE Patents [OSTI]

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.

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

1998-08-04T23:59:59.000Z

177

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

E-Print Network [OSTI]

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 ...

Suwansawat, Suchatvee, 1972-

2002-01-01T23:59:59.000Z

178

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]

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

Myers, Lawrence C.

179

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

SciTech Connect (OSTI)

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.

Guiseppe, Vince

2013-10-01T23:59:59.000Z

180

| International Atomic Energy Agency Nuclear Fusion Nucl. Fusion 54 (2014) 023004 (9pp) doi:10.1088/0029-5515/54/2/023004  

E-Print Network [OSTI]

| International Atomic Energy Agency Nuclear Fusion Nucl. Fusion 54 (2014) 023004 (9pp) doi:10 Tatyana Sizyuk and Ahmed Hassanein Center for Materials under Extreme Environment, School of Nuclear for publication 17 December 2013 Published 21 January 2014 Abstract The plasma shielding effect is a well

Harilal, S. S.

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

E-Print Network [OSTI]

Use of fly ash as an admixture for electromagnetic interference shielding Jingyao Cao, D.D.L. Chung The use of fly ash as an admixture results in enhancement of the electromagnetic interference (EMI of fly ash as an admixture for enhancing the electromagnetic interference (EMI) shielding. EMI shielding

Chung, Deborah D.L.

182

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

E-Print Network [OSTI]

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

McDonald, Kirk

183

Atomic dark matter  

SciTech Connect (OSTI)

We propose that dark matter is dominantly comprised of atomic bound states. We build a simple model and map the parameter space that results in the early universe formation of hydrogen-like dark atoms. We find that atomic dark matter has interesting implications for cosmology as well as direct detection: Weak-scale dark atoms can accommodate hyperfine splittings of order 100 keV, consistent with the inelastic dark matter interpretation of the DAMA data while naturally evading direct detection bounds. Moreover, protohalo formation can be suppressed below M{sub proto} ? 10{sup 3}–10{sup 6}M{sub s}un for weak scale dark matter due to Ion-Radiation and Ion-Atom interactions in the dark sector.

Kaplan, David E.; Krnjaic, Gordan Z.; Rehermann, Keith R.; Wells, Christopher M., E-mail: dkaplan@pha.jhu.edu, E-mail: gordan@pha.jhu.edu, E-mail: keith@pha.jhu.edu, E-mail: cwells13@pha.jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States)

2010-05-01T23:59:59.000Z

184

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

E-Print Network [OSTI]

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...

Kay, Douglas Carey

1982-01-01T23:59:59.000Z

185

The use of isotopically tailored boron for advanced neutron shielding and moderating applications  

E-Print Network [OSTI]

cm. The incident neutron flux was measured first without any shielding slab between the source and the detector. The first slab of shielding material was then placed nearest to the source and the transmitted intensity was measured by the detector... effects of nuclear radiation. This analysis examined the use of isotopically tailored boron for the purpose of moderating, reflecting and shielding neutrons. The source of neutrons in this study varied in energy from 0. 2 keV to 14 MeV. The material...

Deere, Laura Marie

2012-06-07T23:59:59.000Z

186

Increasing transcurium production efficiency through direct resonance shielding  

SciTech Connect (OSTI)

The Radiochemical Engineering Development Center at Oak Ridge National Laboratory is the world s leader in production of 252Cf. This and other heavy actinides are produced by irradiation of mixed curium/americium targets in the High Flux Isotope Reactor. Due to the strong dependence of isotopic cross sections upon incoming neutron energy, the efficiency with which an isotope is transmuted is highly dependent upon the neutron flux energy spectrum and intensities. There are certain energy ranges in which the rate of fissions in feedstock materials can be minimized relative to the rate of (n, ) absorptions. It is shown that by perturbing the flux spectrum, it is possible to alter the net consumption of curium feedstock, as well as the yields of key isotopes for the heavy element research program, such as 249Bk and 252Cf. This flux spectrum perturbation is accomplished by means of focused resonance shielding through the use of filter materials. It is further shown that these perturbations can alter the target yields in a significant way, increasing the amount of 252Cf produced per unit curium consumption by over 40%.

Hogle, Susan L [ORNL; Maldonado, G Ivan [ORNL; Alexander, Charles W [ORNL

2013-01-01T23:59:59.000Z

187

Regulation of biological tissue mineralization through post-nucleation shielding  

E-Print Network [OSTI]

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.

Joshua C. Chang; Robert M. Miura

2015-01-29T23:59:59.000Z

188

MAGNETIC SHIELDING OF EXOMOONS BEYOND THE CIRCUMPLANETARY HABITABLE EDGE  

SciTech Connect (OSTI)

With most planets and planetary candidates detected in the stellar habitable zone (HZ) being super-Earths and gas giants rather than Earth-like planets, we naturally wonder if their moons could be habitable. The first detection of such an exomoon has now become feasible, and due to observational biases it will be at least twice as massive as Mars. However, formation models predict that moons can hardly be as massive as Earth. Hence, a giant planet's magnetosphere could be the only possibility for such a moon to be shielded from cosmic and stellar high-energy radiation. Yet, the planetary radiation belt could also have detrimental effects on exomoon habitability. Here we synthesize models for the evolution of the magnetic environment of giant planets with thresholds from the runaway greenhouse (RG) effect to assess the habitability of exomoons. For modest eccentricities, we find that satellites around Neptune-sized planets in the center of the HZ around K dwarf stars will either be in an RG state and not be habitable, or they will be in wide orbits where they will not be affected by the planetary magnetosphere. Saturn-like planets have stronger fields, and Jupiter-like planets could coat close-in habitable moons soon after formation. Moons at distances between about 5 and 20 planetary radii from a giant planet can be habitable from an illumination and tidal heating point of view, but still the planetary magnetosphere would critically influence their habitability.

Heller, René [McMaster University, Department of Physics and Astronomy, Hamilton, ON L8S 4M1 (Canada)] [McMaster University, Department of Physics and Astronomy, Hamilton, ON L8S 4M1 (Canada); Zuluaga, Jorge I., E-mail: rheller@physics.mcmaster.ca, E-mail: jzuluaga@fisica.udea.edu.co [FACom - Instituto de Física - FCEN, Universidad de Antioquia, Calle 70 No. 52-21, Medellín (Colombia)

2013-10-20T23:59:59.000Z

189

General Corrosion and Localized Corrosion of the Drip Shield  

SciTech Connect (OSTI)

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.

F. Hua; K. Mon

2003-06-24T23:59:59.000Z

190

Optical imaging of Rydberg atoms .  

E-Print Network [OSTI]

??We present an experiment exploring electromagnetically induced transparency (EIT) in Rydberg atoms in order to observe optical nonlinearities at the single photon level. ??Rb atoms… (more)

Mazurenko, Anton

2012-01-01T23:59:59.000Z

191

Rydberg Atoms for Quantum Information.  

E-Print Network [OSTI]

??I examine interactions between ensembles of cold Rydberg atoms, and between Rydberg atoms and an intense, optical standing wave. Because of their strong electrostatic interactions,… (more)

Younge, Kelly Cooper

2010-01-01T23:59:59.000Z

192

Optical atomic magnetometer  

DOE Patents [OSTI]

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.

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

2013-11-19T23:59:59.000Z

193

Metal atomization spray nozzle  

DOE Patents [OSTI]

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.

Huxford, T.J.

1993-11-16T23:59:59.000Z

194

Atomic mass compilation 2012  

SciTech Connect (OSTI)

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.

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

195

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

SciTech Connect (OSTI)

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.

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

1984-07-01T23:59:59.000Z

196

E-Print Network 3.0 - analytic shielding optimization Sample...  

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

of California at San Diego Collection: Plasma Physics and Fusion 57 Electromagnetic interference shielding reaching 70 dB in steel fiber cement Summary: content of 0.72...

197

Multilayer film shields for the protection of PMT from constant magnetic field  

E-Print Network [OSTI]

Photomultiplier tubes (PMTs) are widely used in physical experiments as well as in applied devices. PMTs are sensitive to magnetic field, so creation of effective magnetic shields for their protection is very important. In this paper, the results...

Dmitrenko, V. V.; Besson, David; Nyunt, PhyoWai; Grabchikov, S. S.; Grachev, V. M.; Muraviev-Smirnov, C. C.; Ulin, S. E.; Utechev, Z. M.; Vlasik, K. F.

2015-01-13T23:59:59.000Z

198

Graphit-ceramic RF Faraday-thermal shield and plasma limiter  

DOE Patents [OSTI]

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.

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

1989-01-01T23:59:59.000Z

199

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

E-Print Network [OSTI]

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 ...

Roomy, Thomas Hayward

2012-01-01T23:59:59.000Z

200

Recommendations for a Static Cosmic Ray Shield for Enriched Germanium Detectors  

SciTech Connect (OSTI)

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.

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

2011-09-21T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

The shielding effect of wild type iron reducing bacterial flora on the corrosion of linepipe steel  

E-Print Network [OSTI]

The shielding effect of wild type iron reducing bacterial flora on the corrosion of linepipe steel (iron reducing bacteria (IRB)) on API 5L Ã?52 carbon steel coupons was investigated. A wild type of IRB

202

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

SciTech Connect (OSTI)

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.

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

2011-01-11T23:59:59.000Z

203

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

SciTech Connect (OSTI)

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.

Marshall, A.C.

1986-08-01T23:59:59.000Z

204

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

205

Double active shielded magnetic field gradient design with minimum inductance method  

E-Print Network [OSTI]

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...

Wang, Xu

1992-01-01T23:59:59.000Z

206

Boron cage compound materials and composites for shielding and absorbing neutrons  

DOE Patents [OSTI]

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.

Bowen, III, Daniel E; Eastwood, Eric A

2014-03-04T23:59:59.000Z

207

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

SciTech Connect (OSTI)

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.

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

2000-07-26T23:59:59.000Z

208

Nuclear reactor having a polyhedral primary shield and removable vessel insulation  

DOE Patents [OSTI]

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.

Ekeroth, D.E.; Orr, R.

1993-12-07T23:59:59.000Z

209

Nuclear reactor having a polyhedral primary shield and removable vessel insulation  

DOE Patents [OSTI]

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.

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

1993-01-01T23:59:59.000Z

210

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

SciTech Connect (OSTI)

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.

Keith Rule; Paul Kalb; Pete Kwaschyn

2003-02-11T23:59:59.000Z

211

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

SciTech Connect (OSTI)

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.

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

2003-02-23T23:59:59.000Z

212

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

SciTech Connect (OSTI)

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

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

2011-11-21T23:59:59.000Z

213

Educational Multiwavelength Atomic Emission Spectrometer  

E-Print Network [OSTI]

atomic absorption is the capability for simultaneous multielement analysis. It can be used colleges had acquired atomic absorption instruments by the year 1990.[2] In contrast, atomic emission with the acetylene-air flame source taken from an existing atomic absorption instrument. Two spectrometer units

Nazarenko, Alexander

214

Atomic Force Microscope  

SciTech Connect (OSTI)

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.

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

1988-12-01T23:59:59.000Z

215

Iowa Powder Atomization Technologies  

SciTech Connect (OSTI)

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.

None

2012-01-01T23:59:59.000Z

216

Iowa Powder Atomization Technologies  

ScienceCinema (OSTI)

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.

None

2013-03-01T23:59:59.000Z

217

Atomic Josephson vortices  

SciTech Connect (OSTI)

We show that Josephson vortices in a quasi-one-dimensional atomic Bose Josephson junction can be controllably manipulated by imposing a difference of chemical potentials on the atomic Bose-Einstein condensate waveguides forming the junction. This effect, which has its origin in the Berry phase structure of a vortex, turns out to be very robust in the whole range of the parameters where such vortices can exist. We also propose that a Josephson vortex can be created by the phase imprinting technique and can be identified by a specific tangential feature in the interference picture produced by expanding clouds released from the waveguides.

Kaurov, V. M.; Kuklov, A. B. [Department of Engineering Science and Physics, College of Staten Island, CUNY, Staten Island, New York 10314 (United States)

2006-01-15T23:59:59.000Z

218

Atom Probe Tomography | EMSL  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone byDear Friend,Arthur J. NozikAtom Probe Tomography Atom Probe

219

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone byDear Friend,Arthur J. NozikAtom Probe Tomography Atom

220

Design of a dual species atom interferometer for space  

E-Print Network [OSTI]

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.

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

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Elements & Compounds Atoms (Elements)  

E-Print Network [OSTI]

#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

Frey, Terry

222

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

SciTech Connect (OSTI)

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.

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

223

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

SciTech Connect (OSTI)

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.

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

1999-10-01T23:59:59.000Z

224

Biological shield design and analysis of KIPT accelerator-driven subcritical facility.  

SciTech Connect (OSTI)

Argonne National Laboratory of the United States and Kharkov Institute of Physics and Technology of Ukraine have been collaborating on the conceptual design development of an electron accelerator-driven subcritical facility. The facility will be utilized for performing basic and applied nuclear research, producing medical isotopes, and training young nuclear specialists. This paper presents the design and analyses of the biological shield performed for the top section of the facility. The neutron source driving the subcritical assembly is generated from the interaction of a 100-kW electron beam with a natural uranium target. The electron energy is in the range of 100 to 200 MeV, and it has a uniform spatial distribution. The shield design and the associated analyses are presented including different parametric studies. In the analyses, a significant effort was dedicated to the accurate prediction of the radiation dose outside the shield boundary as a function of the shield thickness without geometrical approximations or material homogenization. The MCNPX Monte Carlo code was utilized for the transport calculation of electrons, photons, and neutrons. Weight window variance-reduction techniques were introduced, and the dose equivalent outside the shield can be calculated with reasonably good statistics.

Zhong, Z.; Gohar, Y.; Nuclear Engineering Division

2009-12-01T23:59:59.000Z

225

Guide to verification and validation of the SCALE-4 radiation shielding software  

SciTech Connect (OSTI)

Whenever a decision is made to newly install the SCALE radiation shielding software on a computer system, the user should run a set of verification and validation (V&V) test cases to demonstrate that the software is properly installed and functioning correctly. This report is intended to serve as a guide for this V&V in that it specifies test cases to run and gives expected results. The report describes the V&V that has been performed for the radiation shielding software in a version of SCALE-4. This report provides documentation of sample problems which are recommended for use in the V&V of the SCALE-4 system for all releases. The results reported in this document are from the SCALE-4.2P version which was run on an IBM RS/6000 work-station. These results verify that the SCALE-4 radiation shielding software has been correctly installed and is functioning properly. A set of problems for use by other shielding codes (e.g., MCNP, TWOTRAN, MORSE) performing similar V&V are discussed. A validation has been performed for XSDRNPM and MORSE-SGC6 utilizing SASI and SAS4 shielding sequences and the SCALE 27-18 group (27N-18COUPLE) cross-section library for typical nuclear reactor spent fuel sources and a variety of transport package geometries. The experimental models used for the validation were taken from two previous applications of the SASI and SAS4 methods.

Broadhead, B.L.; Emmett, M.B.; Tang, J.S.

1996-12-01T23:59:59.000Z

226

Liquid Metal Reactor Program: JASPER US/DOE/PNC Shielding Research Program : Technical progress report, April 1-May 31, 1987  

SciTech Connect (OSTI)

This progress report details activities on the JASPER Shielding Program for the time period of April 1, 1987 through May 31, 1987.

Ingersoll, D.T.; Engle, W.W.; Muckenthaler, F.J.; Slater, C.O.

1987-12-31T23:59:59.000Z

227

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

SciTech Connect (OSTI)

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)

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

1986-06-01T23:59:59.000Z

228

Atom-by-atom nucleation and growth of graphene nanopores  

E-Print Network [OSTI]

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

Golovchenko, Jene A.

229

Orthogonally interdigitated shielded serpentine travelling wave cathode ray tube deflection structure  

DOE Patents [OSTI]

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 a 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, so as 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 figs.

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

1995-07-25T23:59:59.000Z

230

Orthogonally interdigitated shielded serpentine travelling wave cathod ray tube deflection structure  

SciTech Connect (OSTI)

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.

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

1993-10-27T23:59:59.000Z

231

A large-scale magnetic shield with 10^6 damping at milli-Hertz frequencies  

E-Print Network [OSTI]

A magnetically shielded environment with a damping factor larger than one million at the milli-Hertz frequency regime and an extremely low field and gradient over an extended volume is presented. This extraordinary shielding perfomance is to our knowledge unprecedented and represents an improvement of the state of the art in damping the difficult regime of very low-frequency distortions by more than an order of magnitude. Thus, a new generation of high precision measurements in fundamental physics and metrology is enabled with this technology, particularly suitable to find traces of new physics far beyond the reach of accelerator based physics. The technical realization of the shield with its improvements in design is discussed.

Altarev, I; Beck, D H; Chupp, T; Fierlinger, K; Fierlinger, P; Kuchler, F; Lins, T; Marino, M G; Niessen, B; Petzoldt, G; Singh, J T; Schläpfer, U; Schnabel, A; Stoepler, R; Stuiber, S; Strum, M; Taubenheim, B; Voigt, J

2015-01-01T23:59:59.000Z

232

Atomic phenomena in dense plasmas  

SciTech Connect (OSTI)

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)

Weisheit, J.C.

1981-03-01T23:59:59.000Z

233

A microfabricated atomic clock  

SciTech Connect (OSTI)

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.

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

234

Delay in Atomic Photoionization  

SciTech Connect (OSTI)

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.

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

235

Graphite-ceramic rf Faraday-thermal shield and plasma limiter  

DOE Patents [OSTI]

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.

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

1983-05-05T23:59:59.000Z

236

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

SciTech Connect (OSTI)

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.

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

1989-04-01T23:59:59.000Z

237

Multidimensional shielding analysis of the JASPER in-vessel fuel storage experiments  

SciTech Connect (OSTI)

The In-Vessel Fuel Storage (IVFS) experiments analyzed in this report were conducted at the Oak Ridge National Laboratory`s Tower Shielding Reactor (TSR) as part of the Japanese-American Shielding Program for Experimental Research (JASPER). These IVFS experiments were designed to study source multiplication and three-dimensional effects related to in-vessel storage of spent fuel elements in liquid metal reactor (LMR) systems. The present report describes the 2-D and 3-D models, analyses, and calculated results corresponding to a limited subset of those IVFS experiments in which the US LMR program has a particular interest.

Bucholz, J.A.

1993-03-01T23:59:59.000Z

238

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

SciTech Connect (OSTI)

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.

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

2012-04-15T23:59:59.000Z

239

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

SciTech Connect (OSTI)

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.

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

2005-08-01T23:59:59.000Z

240

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

SciTech Connect (OSTI)

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.

Buckner, M.R.

2001-08-09T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Nucleonic analysis of a preliminary design for the ETF neutral-beam-injector duct shielding  

SciTech Connect (OSTI)

A nucleonic analysis of the Engineering Test Facility Neutral-Beam-Injector duct shielding 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 a subsequent discrete-ordinates calculation of the neutron and gamma-ray transport through the shield. The analysis also included determination of the energy and angular distribution of neutrons and gamma rays entering the duct from the torus plasma chamber. Confidence in the hybrid method and the results obtained were provided through a comparison with three-dimensional Monte Carlo results.

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

1980-01-01T23:59:59.000Z

242

Appendix G: Radiation HYDROGEN ATOM  

E-Print Network [OSTI]

. People are exposed to naturally occurring radiation constantly. For example, cosmic radiation; radon effects on the environment and biological systems. Radiation comes from natural and human-made sourcesAppendix G: Radiation #12;#12;P P P E E E N NN HYDROGEN ATOM DEUTERIUM ATOM TRITIUM ATOM HYDROGEN

Pennycook, Steve

243

Appendix A: Radiation HYDROGEN ATOM  

E-Print Network [OSTI]

. People are exposed to naturally occurring radiation constantly. For example, cosmic radiation; radon effects on the environment and biological systems. Radiation comes from natural and human-made sourcesAppendix A: Radiation #12;P P P E E E N NN HYDROGEN ATOM DEUTERIUM ATOM TRITIUM ATOM HYDROGEN

Pennycook, Steve

244

VARIOUS APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY  

E-Print Network [OSTI]

APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPYthe Zeeman effect to atomic absorption spectroscopy has beenthe Zeeman effect on atomic absorption spectrometry has been

Koizumi, Hideaki

2011-01-01T23:59:59.000Z

245

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...

246

Shielding analysis and design of the KIPT experimental neutron source facility of Ukraine.  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility based on the use of an electron accelerator driven subcritical (ADS) facility [1]. The facility uses the existing electron accelerators of KIPT in Ukraine. The neutron source of the sub-critical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The electron beam has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Reactor physics experiments and material performance characterization will also be carried out. The subcritical assembly is driven by neutrons generated by the electron beam interactions with the target material. A fraction of these neutrons has an energy above 50 MeV generated through the photo nuclear interactions. This neutron fraction is very small and it has an insignificant contribution to the subcritical assembly performance. However, these high energy neutrons are difficult to shield and they can be slowed down only through the inelastic scattering with heavy isotopes. Therefore the shielding design of this facility is more challenging relative to fission reactors. To attenuate these high energy neutrons, heavy metals (tungsten, iron, etc.) should be used. To reduce the construction cost, heavy concrete with 4.8 g/cm{sup 3} density is selected as a shielding material. The iron weight fraction in this concrete is about 0.6. The shape and thickness of the heavy concrete shield are defined to reduce the biological dose equivalent outside the shield to an acceptable level during operation. At the same time, special attention was give to reduce the total shield mass to reduce the construction cost. The shield design is configured to maintain the biological dose equivalent during operation {le} 0.5 mrem/h inside the subcritical hall, which is five times less than the allowable dose for working forty hours per week for 50 weeks per year. This study analyzed and designed the thickness and the shape of the radial and top shields of the neutron source based on the biological dose equivalent requirements inside the subcritical hall during operation. The Monte Carlo code MCNPX is selected because of its capabilities for transporting electrons, photons, and neutrons. Mesh based weight windows variance reduction technique is utilized to estimate the biological dose outside the shield with good statistics. A significant effort dedicated to the accurate prediction of the biological dose equivalent outside the shield boundary as a function of the shield thickness without geometrical approximations or material homogenization. The building wall was designed with ordinary concrete to reduce the biological dose equivalent to the public with a safety factor in the range of 5 to 20.

Zhong, Z.; Gohar, M. Y. A.; Naberezhnev, D.; Duo, J.; Nuclear Engineering Division

2008-10-31T23:59:59.000Z

247

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

E-Print Network [OSTI]

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

Fritz, Harald

248

Optics and interferometry with atoms and molecules  

E-Print Network [OSTI]

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 ...

Cronin, Alexander D.

249

Atom Probe Tomography | EMSL  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAboutScience Program Cumulus Humilis Aerosol Processing Study (CHAPS)Atom

250

An Evaluation of Shadow Shielding for Lunar System Waste Heat Rejection  

E-Print Network [OSTI]

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...

Worn, Cheyn

2012-07-16T23:59:59.000Z

251

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

E-Print Network [OSTI]

' Drives, Community Events, EV Ambassadors #12;Thank-you! 10 10 Questions? #12;Electric Vehicles: Timeline1 The City of Vancouver's Approach to Electric Vehicles: 7 Pillars Malcolm Shield, Climate Policy. Integrated EV Charging and Cellular Infrastructure Trial 6 #12;5. CoV Fleet EVs 7 · First Mitsubishi Electric

California at Davis, University of

252

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

E-Print Network [OSTI]

Radiation shielding of high-energy neutrons in SAD P. Seltborg1 , A. Polanski2 , S. Petrochenkov2 101 000, PB78, Moscow, Russia Abstract The radiation fields and the effective dose at the SubSv/h. This value meets the dose limits according to Russian radiation protection regulations, provided that access

253

Gravity anomalies of the Northern Hawaiian Islands: Implications on the shield evolutions of Kauai and Niihau  

E-Print Network [OSTI]

Gravity anomalies of the Northern Hawaiian Islands: Implications on the shield evolutions of Kauai January 2010; accepted 16 March 2010; published 31 August 2010. [1] New land and marine gravity data reveal two positive residual gravity anomalies in the Northern Hawaiian Islands: one over Kaua

Ito, Garrett

254

Nicole Hudson Sillerman Center Summer Internship at the Blue Cross Blue Shield of Massachusetts Foundation  

E-Print Network [OSTI]

Foundation Reflection Paper As a result of the generosity of the Sillerman Center for the Advancement of Philanthropy, I had the privilege of interning at The Blue Cross Blue Shield of Massachusetts Foundation (the Foundation) during the summer of 2011. The Foundation was founded in 2001 with an endowment from Blue Cross

Snider, Barry B.

255

Progress In Electromagnetics Research B, Vol. 15, 197215, 2009 MODELING OF SHIELDING COMPOSITE MATERIALS  

E-Print Network [OSTI]

Progress In Electromagnetics Research B, Vol. 15, 197­215, 2009 MODELING OF SHIELDING COMPOSITE B. Archambeault IBM Co. Research Triangle Park, NC, USA Abstract--Composites containing conducting structures are studied, with both absorbing and reflecting composite layers. In this paper, fiber

Koledintseva, Marina Y.

256

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

E-Print Network [OSTI]

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

Princeton Plasma Physics Laboratory

257

Submillimeter-resolution radiography of shielded structures with laser-accelerated electron beams  

E-Print Network [OSTI]

Submillimeter-resolution radiography of shielded structures with laser-accelerated electron beams (Received 24 March 2010; published 14 October 2010) We investigate the use of energetic electron beams beam (with energy >100 MeV) was generated by the process of laser-wakefield acceleration through

Umstadter, Donald

258

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

259

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

DOE Patents [OSTI]

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.

Hondorp, Hugh L. (Princeton Junction, NJ)

1984-01-01T23:59:59.000Z

260

Fusion Engineering and Design 42 (1998) 235245 Verification of ITER shielding capability and FENDL data  

E-Print Network [OSTI]

of the calculated-to-experimental (C/E) data. These two objectives will guide designers with regard and calculated data that should be implemented in the design process. Both differential and integral experimentalFusion Engineering and Design 42 (1998) 235­245 Verification of ITER shielding capability and FENDL

Abdou, Mohamed

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Optimized optomechanical crystal cavity with acoustic radiation shield Jasper Chan, Amir H. Safavi-Naeini, Jeff T. Hill, Sen Meenehan, and Oskar Painter  

E-Print Network [OSTI]

Optimized optomechanical crystal cavity with acoustic radiation shield Jasper Chan, Amir H. Safavi://apl.aip.org/about/rights_and_permissions #12;Optimized optomechanical crystal cavity with acoustic radiation shield Jasper Chan, Amir H. Safavi

Painter, Oskar

262

Construction of a Post-Irradiated Fuel Examination Shielded Enclosure Facility  

SciTech Connect (OSTI)

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.

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

2008-05-01T23:59:59.000Z

263

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

SciTech Connect (OSTI)

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.

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

264

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...

265

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

E-Print Network [OSTI]

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

Stoiciu, Mihai

266

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

E-Print Network [OSTI]

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

Stoiciu, Mihai

267

High efficiency direct detection of ions from resonance ionization of sputtered atoms  

DOE Patents [OSTI]

A method and apparatus are provided for trace and other quantitative analysis with high efficiency of a component in a sample, with the analysis involving the removal by ion or other bombardment of a small quantity of ion and neutral atom groups from the sample, the conversion of selected neutral atom groups to photoions by laser initiated resonance ionization spectroscopy, the selective deflection of the photoions for separation from original ion group emanating from the sample, and the detection of the photoions as a measure of the quantity of the component. In some embodiments, the original ion group is accelerated prior to the RIS step for separation purposes. Noise and other interference are reduced by shielding the detector from primary and secondary ions and deflecting the photoions sufficiently to avoid the primary and secondary ions.

Gruen, Dieter M. (Downers Grove, IL); Pellin, Michael J. (Oak Brook, IL); Young, Charles E. (Westmont, IL)

1986-01-01T23:59:59.000Z

268

High efficiency direct detection of ions from resonance ionization of sputtered atoms  

DOE Patents [OSTI]

A method and apparatus are provided for trace and other quantitative analysis with high efficiency of a component in a sample, with the analysis involving the removal by ion or other bombardment of a small quantity of ion and neutral atom groups from the sample, the conversion of selected neutral atom groups to photoions by laser initiated resonance ionization spectroscopy, the selective deflection of the photoions for separation from original ion group emanating from the sample, and the detection of the photoions as a measure of the quantity of the component. In some embodiments, the original ion group is accelerated prior to the RIS step for separation purposes. Noise and other interference are reduced by shielding the detector from primary and secondary ions and deflecting the photoions sufficiently to avoid the primary and secondary ions.

Gruen, D.M.; Pellin, M.J.; Young, C.E.

1985-01-16T23:59:59.000Z

269

Rydberg Atoms in Ponderomotive Potentials.  

E-Print Network [OSTI]

??In this thesis, we examine the ponderomotive interaction between an applied optical field and a highly excited Rydberg electron. An atom in a Rydberg state… (more)

Knuffman, Brenton J.

2009-01-01T23:59:59.000Z

270

Absorption properties of identical atoms  

SciTech Connect (OSTI)

Emission rates and other optical properties of multi-particle 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. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions.

Sancho, Pedro, E-mail: psanchos@aemet.es

2013-09-15T23:59:59.000Z

271

Similarity between positronium-atom and electron-atom scattering  

E-Print Network [OSTI]

We employ the impulse approximation for description of positronium-atom scattering. Our analysis and calculations of Ps-Kr and Ps-Ar collisions provide theoretical explanation of the similarity between the cross sections for positronium scattering and electron scattering for a range of atomic and molecular targets observed by S. J. Brawley et al. [Science 330, 789 (2010)].

Fabrikant, I I

2015-01-01T23:59:59.000Z

272

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

SciTech Connect (OSTI)

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.

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

2010-07-18T23:59:59.000Z

273

Coherent Atom Optics with fast metastable rare gas atoms  

SciTech Connect (OSTI)

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.

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

274

E-Print Network 3.0 - atomization atomic absorption Sample Search...  

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

atomic absorption Search Powered by Explorit Topic List Advanced Search Sample search results for: atomization atomic absorption Page: << < 1 2 3 4 5 > >> 1 :coherently trapped in...

275

Bogoliubov theory and bosonic atoms  

E-Print Network [OSTI]

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.

Phan Thanh Nam

2011-09-13T23:59:59.000Z

276

Integrity evaluation of lower thermal shield under exposure to HFBR environment  

SciTech Connect (OSTI)

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.

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

277

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

SciTech Connect (OSTI)

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.

Michael Kruzic

2007-09-01T23:59:59.000Z

278

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

DOE Patents [OSTI]

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.

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

1982-12-28T23:59:59.000Z

279

A magnetically shielded room with ultra low residual field and gradient  

SciTech Connect (OSTI)

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.

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

280

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

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Spectral Emission of Moving Atom  

E-Print Network [OSTI]

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.

J. X. Zheng-Johansson

2008-03-17T23:59:59.000Z

282

IDS120h GEOMETRY WITH SHIELDING VESSELS ENERGY FLOW ANALYSIS CONTINUED  

E-Print Network [OSTI]

AREAS Np = 100,000 AND 500,000 EVENTS Np = 100,000 (1) Np = 500,000 (2) (1) SH#1-4: 1684.27 kW --> 1603/g PEAK VALUE FOR 8-10 cm LENGTH JUST AFTER BP1 SECTION, BUT IT IS ISOLATED ONLY ALONG -x AXIS REGION BEADS/He SHIELDING. 9 BP1 (~50 cm), BP2 (~10 cm) Be SECTIONS WORK STILL IN PROGRESS. #12;

McDonald, Kirk

283

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

SciTech Connect (OSTI)

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.

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

1981-01-01T23:59:59.000Z

284

EMI shield enhancement through the addition of copper coated glass fibers  

E-Print Network [OSTI]

E. , University of Wisconsin-Madison Chair of Committee: Dr. G. W. Halldin This research investigated the feasibility of using copper coated glass fibers to increase the EMI shielding characteristics of vinyl ester thermosetting resin. The fibers were coated... 35 36 37 41 41 48 55 57 58 58 58 58 60 61 62 62 62 Plate Times. Surface Area Analysis Scanning Electron Microscopy. MOLDED COMPOSITE MATERIALS. Resin. Sample Preparation. Evaluation. Scanning Electron Microscopy Flexural...

Montanye, Jeffrey Richard

1988-01-01T23:59:59.000Z

285

Turbulence in Atomic Hydrogen  

E-Print Network [OSTI]

Understanding the properties of interstellar turbulence is a great intellectual challenge and the urge to solve this problem is partially motivated by a necessity to explain the star formation mystery. This review deals with a recently suggested inversion technique as applied to atomic hydrogen. This technique allows to determine 3D turbulence statistics through the variations of 21 cm intensity. We claim that a radio interferometer is an ideal tool for such a study as its visibility function is directly related to the statistics of galactic HI. Next, we show how galactic rotation curve can be used to study the turbulence slice by slice and relate the statistics given in galactic coordinates and in the velocity space. The application of the technique to HI data reveals a shallow spectrum of the underlying HI density that is not compatible with a naive Kolmogorov picture. We show that the random density corresponding to the found spectrum tends to form low contrast filaments that are elongated towards the observer.

A. Lazarian

1998-04-02T23:59:59.000Z

286

Supersonic coal water slurry fuel atomizer  

DOE Patents [OSTI]

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.

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

1991-01-01T23:59:59.000Z

287

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

SciTech Connect (OSTI)

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.

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

288

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

SciTech Connect (OSTI)

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)

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

289

Shielding Studies for the CERN Super-Proton-Synchrotron at Experimental Point 5  

E-Print Network [OSTI]

The European Laboratory for Particle Research, CERN has been operated the Super Proton Sychrotron (SPS) for more than 30 years with the shielding design knowledge of the early 70s. At that time particle transport codes were neither available nor capable of dealing with deep lateral shielding calculations. For the future LHC increasing projected values of beam intensity in the SPS and decreasing limits to radiation exposure have led to the need to re-assess the shielding at point 5 of the SPS. 20 years ago this area housed the UA1 experiment of Carlo Rubbia (nobel-price 1984). The thesis describes a re-assessment based on simulations using the multi-purpose radiation transport codes FLUKA and MCNPX. The latter one was utilized for geometry design and to compare variance reduction methods. Different assumed beam-loss points along the beam-line together with fluence-to-doserate conversion calculations were used to find the worst case scenario. Dose-rates as well as particle-energy spectra inside the accessible a...

Müller, Mario J

2004-01-01T23:59:59.000Z

290

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

SciTech Connect (OSTI)

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.

Sherrell, D.L.

1992-06-01T23:59:59.000Z

291

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

SciTech Connect (OSTI)

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.

Sherrell, D.L.

1992-06-01T23:59:59.000Z

292

The magnetic shielding for the neutron decay spectrometer aSPECT  

E-Print Network [OSTI]

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.

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

293

Castor-1C spent fuel storage cask decay heat, heat transfer, and shielding analyses  

SciTech Connect (OSTI)

This report documents the decay heat, heat transfer, and shielding analyses of the Gesellschaft fuer Nuklear Services (GNS) CASTOR-1C cask used in a spent fuel storage demonstration performed at Preussen Elektra's Wurgassen nuclear power plant. The demonstration was performed between March 1982 and January 1984, and resulted in cask and fuel temperature data and cask exterior surface gamma-ray and neutron radiation dose rate measurements. The purpose of the analyses reported here was to evaluate decay heat, heat transfer, and shielding computer codes. The analyses consisted of (1) performing pre-look predictions (predictions performed before the analysts were provided the test data), (2) comparing ORIGEN2 (decay heat), COBRA-SFS and HYDRA (heat transfer), and QAD and DOT (shielding) results to data, and (3) performing post-test analyses if appropriate. Even though two heat transfer codes were used to predict CASTOR-1C cask test data, no attempt was made to compare the two codes. The codes are being evaluated with other test data (single-assembly data and other cask data), and to compare the codes based on one set of data may be premature and lead to erroneous conclusions.

Rector, D.R.; McCann, R.A.; Jenquin, U.P.; Heeb, C.M.; Creer, J.M.; Wheeler, C.L.

1986-12-01T23:59:59.000Z

294

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

SciTech Connect (OSTI)

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.

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

295

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

SciTech Connect (OSTI)

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.

Couture, A.

2013-06-07T23:59:59.000Z

296

Conduction Effect of Thermal Radiation in a Metal Shield Pipe in a Cryostat for a Cryogenic Interferometric Gravitational Wave Detector  

E-Print Network [OSTI]

A large heat load caused by thermal radiation through a metal shield pipe was observed in a cooling test of a cryostat for a prototype of a cryogenic interferometric gravitational wave detector. The heat load was approximately 1000 times larger than the value calculated by the Stefan-Boltzmann law. We studied this phenomenon by simulation and experiment and found that it was caused by the conduction of thermal radiation in a metal shield pipe.

Takayuki Tomaru; Masao Tokunari; Kazuaki Kuroda; Takashi Uchiyama; Akira Okutomi; Masatake Ohashi; Hiroyuki Kirihara; Nobuhiro Kimura; Yoshio Saito; Nobuaki Sato; Takakazu Shintomi; Toshikazu Suzuki; Tomiyoshi Haruyama; Shinji Miyoki; Kazuhiro Yamamoto; Akira Yamamoto

2007-11-06T23:59:59.000Z

297

E-Print Network 3.0 - atom traps atomic Sample Search Results  

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

for: atom traps atomic Page: << < 1 2 3 4 5 > >> 1 An output coupler for Bose condensed atoms The observations of BEC have stimulated interest in atom lasers, coherent sources of...

298

Atoms 2014, 2, 378-381; doi:10.3390/atoms2030378 OPEN ACCESS  

E-Print Network [OSTI]

Atoms 2014, 2, 378-381; doi:10.3390/atoms2030378 OPEN ACCESS atomsISSN 2218-2004 www.mdpi.com/journal/atoms.calisti@univ-amu.fr 3 International Atomic Energy Agency, Atomic and Molecular Data Unit, Nuclear Data Section, P.O. Box for the first two SLSP workshops are for simple atomic systems: the hydrogen atom or hydrogen-like one

299

Chemical factors influencing selenium atomization  

E-Print Network [OSTI]

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...

Buren, Mary Sue

1980-01-01T23:59:59.000Z

300

Summary of Disposable Debris Shields (DDS) Analysis for Development of Solid Debris Collection at NIF  

SciTech Connect (OSTI)

Collection of solid debris from the National Ignition Facility (NIF) is being developed both as a diagnostic tool and as a means for measuring nuclear reaction cross sections relevant to the Stockpile Stewardship Program and nuclear astrophysics. The concept is straightforward; following a NIF shot, the debris that is produced as a result of the capsule and hohlraum explosion would be collected and subsequently extracted from the chamber. The number of nuclear activations that occurred in the capsule would then be measured through a combination of radiation detection and radiochemical processing followed by mass spectrometry. Development of the catcher is challenging due to the complex environment of the NIF target chamber. The collector surface is first exposed to a large photon flux, followed by the debris wind that is produced. The material used in the catcher must be mechanically strong in order to withstand the large amount of energy it is exposed to, as well as be chemically compatible with the form and composition of the debris. In addition, the location of the catcher is equally important. If it is positioned too close to the center of the target chamber, it will be significantly ablated, which could interfere with the ability of the debris to reach the surface and stick. If it is too far away, the fraction of the debris cloud collected will be too small to result in a statistically significant measurement. Material, geometric configuration, and location must all be tested in order to design the optimal debris collection system for NIF. One of the first ideas regarding solid debris collection at NIF was to use the disposable debris shields (DDS), which are fielded over the final optics assemblies (FOA) 7 m away from the center of the target chamber. The DDS are meant to be replaced after a certain number of shots, and if the shields could be subsequently analyzed after removal, it would serve as a mechanism for fielding a relatively large collection area through the use of a part meant to be replaced regularly. The solid angle covered by one of the shields is roughly 10{sup -4} of 4{pi}. If several shields were analyzed at once, it would increase the solid angle of the collection area accordingly. The glass shields consist of ammonia hardened silica with a sol gel coating and kapton tape around the edge. The square sheets are 14-inch on each side. The original shields were 1 mm thick, but it was determined that a thicker shield (3.3 mm) was more effective in preventing debris from reaching the FOA. The Solid Radchem group received two sets of DDS as part of our evaluation of the potential use of the DDS as solid debris collectors. The first set consisted of two 3.3 mm shields, one each from the top and bottom of the chamber (the '3mm set'). The second set consisted of four 1mm shields, one from the top of the chamber and the other three from the bottom (the 'IFSA set'). For each set, the shields were cut into smaller subsamples, which were then imaged using scanning electron microscopy (SEM) followed by chemical leaching and mass spectrometry. The purpose was to evaluate both the quantity and identity of the debris that was present on the DDS surfaces, and to determine if any of the capsule debris was reaching the chamber walls. In addition, potential enhancement due to gravity in the chamber was evaluated by directly comparing shields fielded in the top and bottom of the chamber. Based on the results, the use of the DDS as debris collectors would be evaluated. The results from both sets were presented to the DDS Working Group. The slides are attached to this document. The 3mm set results are presented first, followed by the results from the IFSA set. In both cases it was determined that a small fraction of the overall debris field was collected on the DDS. This means that the debris that is formed during a NIF shot is condensing out of the plasma and depositing on surfaces closer to the target chamber center, or else it is simply falling to the bottom of the chamber. In either case, it was determined that using

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

2011-11-20T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

THE INTERACTION OF RARE GAS METASTABLE ATOMS  

E-Print Network [OSTI]

in the study of metastable atom reactions. > 1 it- Fig, laa raetastable rare gas atom, three quantities are necessaryOF iiARE GAS METASTABLF ATOMS Andrew Zun-Foh Wang M a t e r

Wang, A.Z.-F.

2011-01-01T23:59:59.000Z

302

Imaging atoms in 3-D  

SciTech Connect (OSTI)

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

Ercius, Peter

2013-10-31T23:59:59.000Z

303

Imaging atoms in 3-D  

ScienceCinema (OSTI)

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

Ercius, Peter

2014-06-27T23:59:59.000Z

304

Absorption properties of identical atoms  

E-Print Network [OSTI]

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.

Pedro Sancho

2013-07-31T23:59:59.000Z

305

Recent Progress in ultracold atoms  

E-Print Network [OSTI]

, 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

Baltisberger, Jay H.

306

Neutron source in the MCNPX shielding calculating for electron accelerator driven facility  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Inst. of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of an experimental neutron source facility. It is an accelerator driven system (ADS) utilizing a subcritical assembly driven by electron accelerator. The facility will be utilized for performing basic and applied nuclear researches, producing medical isotopes, and training young nuclear specialists. Monte Carlo code MCNPX has been utilized as a design tool due to its capability to transport electrons, photons, and neutrons at high energies. However the facility shielding calculations with MCNPX need enormous computational resources and the small neutron yield per electron makes sampling difficulty for the Monte Carlo calculations. A method, based on generating and utilizing neutron source file, was proposed and tested. This method reduces significantly the required computer resources and improves the statistics of the calculated neutron dose outside the shield boundary. However the statistical errors introduced by generating the neutron source were not directly represented in the results, questioning the validity of this methodology, because an insufficiently sampled neutron source can cause error on the calculated neutron dose. This paper presents a procedure for the validation of the generated neutron source file. The impact of neutron source statistic on the neutron dose is examined by calculating the neutron dose as a function of the number of electron particles used for generating the neutron source files. When the value of the calculated neutron dose converges, it means the neutron source has scored sufficient records and statistic does not have apparent impact on the calculated neutron dose. In this way, the validity of neutron source and the shield analyses could be verified. (authors)

Zhong, Z.; Gohar, Y. [Nuclear Engineering Div., Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

2012-07-01T23:59:59.000Z

307

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

SciTech Connect (OSTI)

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.

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

308

A robust and well shielded thermal conductivity device for low temperature measurements  

SciTech Connect (OSTI)

We present a compact mechanically robust thermal conductivity measurement apparatus for measurements at low temperatures (<1 K) and high magnetic fields on small high-purity single crystal samples. A high-conductivity copper box is used to enclose the sample and all the components. The box provides protection for the thermometers, heater, and most importantly the sample increasing the portability of the mount. In addition to physical protection, the copper box is also effective at shielding radio frequency electromagnetic interference and thermal radiation, which is essential for low temperature measurements. A printed circuit board in conjunction with a braided ribbon cable is used to organize the delicate wiring and provide mechanical robustness.

Toews, W. H.; Hill, R. W. [GWPI and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)] [GWPI and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2014-04-15T23:59:59.000Z

309

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

SciTech Connect (OSTI)

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.

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

2012-05-14T23:59:59.000Z

310

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

SciTech Connect (OSTI)

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.

Michael R. Kruzic

2008-06-01T23:59:59.000Z

311

SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SYNCHROTRON LIGHT SOURCE  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 ResourceAwards SAGE Awards ,# ,Schools WhenSectionSHIELDING

312

Advantages of the shielded containers at the Waste Isolation Pilot Plant.  

SciTech Connect (OSTI)

The Waste Isolation Pilot Plant (WIPP) disposal operations currently employ two different disposal methods: one for Contact Handled (CH) waste and another for Remote Handled (RH) waste. CH waste is emplaced in a variety of payload container configurations on the floor of each disposal room. In contrast, RH waste is packaged into a single type of canister and emplaced in pre-drilled holes in the walls of disposal rooms. Emplacement of the RH waste in the walls must proceed in advance of CH waste emplacement and therefore poses logistical constraints, in addition to the loss of valuable disposal capacity. To improve operational efficiency and disposal capacity, the Department of Energy (DOE) has proposed a shielded container for certain RH waste streams. RH waste with relatively low gammaemitting activity would be packaged in lead-lined containers, shipped to WIPP in existing certified transportation packages for CH waste and emplaced in WIPP among the stacks of CH waste containers on the floor of a disposal room. RH waste with high gamma-emitting activity would continue to be emplaced in the boreholes along the walls. The new RH container is similar to the nominal 208-liter (55-gallon) drum, however it includes about 2.5 cm (1 in) of lead, sandwiched between thick steel sheets. Furthermore, the top and bottom are made of thick plate steel to strengthening the package to meet transportation requirements. This robust configuration provides an overpack for materials that otherwise would be RH waste. This paper describes the container and the regulatory approach used to meet the requirements imposed by regulations that apply to WIPP. This includes a Performance Assessment used to evaluate WIPP's long-term performance and the DOE's approach to gain approval for the transportation of shielded containers. This paper also describes estimates of the DOE's RH transuranic waste inventory that may be packaged and emplaced in shielded containers. Finally, the paper includes a discussion of how the DOE proposes to track the waste packaged into shielded containers against the RH waste inventory and how this will comply with the regulated volume.

Nelson, Roger A. (U.S. Department of Energy, Carlsbad, NM); Dunagan, Sean C.

2010-05-01T23:59:59.000Z

313

Shields Warren, 1971 | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadore Perlman, 1960Real PropertyScience» SelectingSheldon Wolff,Shields

314

Selfish atom selects quantum resonances at fractional atomic frequencies  

E-Print Network [OSTI]

We show that the atom as a "quantum entity", driven by an external field in the form of pulse sequence at repetition rate equal to the internal quantum frequency divided by an integer n, responds resonantly. It seeks and finds its characteristic frequencies in any possible combination of its frequencies. This is an indication of self expression by the atom at many sub-frequencies of its own transition frequencies. It is a non-intuitive phenomenon since the external repetition rate has no quantum character, yet the atom responds to it if the rate is equal to 1/n its eigen-frequency. We believe that our results will have implications in other quantum related processes, such as resonant enhancement of chemical reactions and biological processes.

Gennady A. Koganov; Reuben Shuker

2014-09-17T23:59:59.000Z

315

RICE UNIVERSITY Ultracold Collisions in Atomic Strontium  

E-Print Network [OSTI]

RICE UNIVERSITY Ultracold Collisions in Atomic Strontium by Sarah B. Nagel A Thesis Submitted Houston, Texas February, 2008 #12;Abstract Ultracold Collisions in Atomic Strontium by Sarah B. Nagel In this work with atomic Strontium, the atoms are first laser cooled and subse- quently trapped, in a MOT

Killian, Thomas C.

316

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

317

Atomic Cascade in Muonic and Hadronic Hydrogen Atoms  

E-Print Network [OSTI]

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.

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

2007-12-18T23:59:59.000Z

318

Observation of relativistic antihydrogen atoms  

SciTech Connect (OSTI)

An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

Blanford, Glenn DelFosse

1998-01-01T23:59:59.000Z

319

Quantum Electrodynamics of Atomic Resonances  

E-Print Network [OSTI]

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.

Miguel Ballesteros; Jérémy Faupin; Jürg Fröhlich; Baptiste Schubnel

2015-03-09T23:59:59.000Z

320

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

SciTech Connect (OSTI)

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.

Marshall, A.C.

1997-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Atomizing, continuous, water monitoring module  

DOE Patents [OSTI]

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.

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

1997-01-01T23:59:59.000Z

322

Atomizing, continuous, water monitoring module  

DOE Patents [OSTI]

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.

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

1997-07-08T23:59:59.000Z

323

Degeneracy Breaking of Hydrogen Atom  

E-Print Network [OSTI]

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.

Agung Trisetyarso; Pantur Silaban

2014-11-21T23:59:59.000Z

324

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

SciTech Connect (OSTI)

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.

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

325

Comparison of analytic Whipple bumper shield ballistic limits with CTH simulations  

SciTech Connect (OSTI)

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.

Hertel, E.S. Jr.

1993-05-01T23:59:59.000Z

326

Environment on the Surfaces of the Drip Shield and Waste Package Outer Barrier  

SciTech Connect (OSTI)

This report provides supporting analysis of the conditions at which an aqueous solution can exist on the drip shield or waste package surfaces, including theoretical underpinning for the evolution of concentrated brines that could form by deliquescence or evaporation, and evaluation of the effects of acid-gas generation on brine composition. This analysis does not directly feed the total system performance assessment for the license application (TSPA-LA), but supports modeling and abstraction of the in-drift chemical environment (BSC 2004 [DIRS 169863]; BSC 2004 [DIRS 169860]). It also provides analyses that may support screening of features, events, and processes, and input for response to regulatory inquiries. This report emphasizes conditions of low relative humidity (RH) that, depending on temperature and chemical conditions, may be dry or may be associated with an aqueous phase containing concentrated electrolytes. Concentrated solutions at low RH may evolve by evaporative concentration of water that seeps into emplacement drifts, or by deliquescence of dust on the waste package or drip shield surfaces. The minimum RH for occurrence of aqueous conditions is calculated for various chemical systems based on current understanding of site geochemistry and equilibrium thermodynamics. The analysis makes use of known characteristics of Yucca Mountain waters and dust from existing tunnels, laboratory data, and relevant information from the technical literature and handbooks.

T. Wolery

2005-02-22T23:59:59.000Z

327

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

SciTech Connect (OSTI)

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.

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

328

Comparison Of Hybrid Methods For Global Variance Reduction In Shielding Calculations  

SciTech Connect (OSTI)

For Monte Carlo shielding problems that calculate a mesh tally over the entire problem, the relative uncertainties computed for each voxel can vary widely. This can lead to unacceptably long run times in order to reduce the uncertainties in all areas of the problem to a reasonably low level. Hybrid methods using estimates from deterministic calculations to create importance maps for variance reduction in Monte Carlo calculations have been successfully used to optimize the calculation of specific tallies. For the global problem, several methods have been proposed that create importance maps that distribute Monte Carlo particles in such a way as to achieve a more uniform distribution of relative uncertainty across the problem. The goal is to compute a mesh tally with nearly the same relative uncertainties in the low flux/dose areas as in the high flux/dose areas. Methods based on only forward deterministic estimates and methods using both forward and adjoint deterministic methods have been implemented the SCALE/MAVRIC package and have been compared against each other by computing global mesh tallies on several representative shielding problems. Methods using both forward and adjoint estimates provide better performance for computing more uniform relative uncertainties across a global mesh tally.

Peplow, Douglas E. [ORNL

2013-01-01T23:59:59.000Z

329

Comparison of hybrid methods for global variance reduction in shielding calculations  

SciTech Connect (OSTI)

For Monte Carlo shielding problems that calculate a mesh tally over the entire problem, the statistical uncertainties computed for each voxel can vary widely. This can lead to unacceptably long run times in order to reduce the uncertainties in all areas of the problem to a reasonably low level. Hybrid methods - using estimates from deterministic calculations to create importance maps for variance reduction in Monte Carlo calculations - have been successfully used to optimize the calculation of specific tallies. For the global problem, several methods have been proposed to create importance maps that distribute Monte Carlo particles in such a way as to achieve a more uniform distribution of relative uncertainty across the problem. The goal is to compute a mesh tally with nearly the same relative uncertainties in the low flux/dose areas as in the high flux/dose areas. Methods based on only forward deterministic estimates and methods using both forward and adjoint deterministic methods have been implemented in the SCALE/MAVRIC package and have been compared against each other by computing global mesh tallies on several representative shielding problems. Methods using both forward and adjoint estimates provide better performance for computing more uniform relative uncertainties across a global mesh tally. (authors)

Peplow, D. E. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6170 (United States)

2013-07-01T23:59:59.000Z

330

Design of an active shield dipole magnet in the interaction region of the KEK B-Factory  

SciTech Connect (OSTI)

Due to their detrimental effect on the experimental detector of the KEK B-Factory, the leakage fields of the bending magnets, which will be installed near to the collision point, need to be as small as possible. For achieving this smaller leakage field, the authors propose a special superconducting dipole with a shield coil. A novel approach for achieving a leakage field of less than 5 mT at a radius of 200 mm, based on an active shield method, has been investigated. The design concept of the coil, which consists of a main coil and a shield coil having an opposite current to the main coil, has been developed. The coil design and the structure of the magnet are described.

Tsuchiya, K.; Kobayashi, T.M.; Haruyama, T.; Ajima, Y.; Doi, Y.; Ohuchi, N.; Kurokawa, S. [National Lab. for High Energy Physics, Ibaraki (Japan); Kimura, A. [Graduate Univ. for Advanced Studies, Ibaraki (Japan)

1994-12-31T23:59:59.000Z

331

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

SciTech Connect (OSTI)

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.

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

2011-10-01T23:59:59.000Z

332

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

SciTech Connect (OSTI)

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.

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

1996-09-01T23:59:59.000Z

333

JASPER [Japanese-American Shielding Program of Experimental Research], USDOE/PNC shielding research program: Analysis of the JASPER fission gas plenum experiment  

SciTech Connect (OSTI)

The results of the analysis of the Fission Gas Plenum Experiment are presented. This experiment is the second in a series of several experiments comprising a joint US DOE-Japan PNC Shielding Research Program (JASPER). The four Fission Gas Plenum Experiment configurations, designed for the measurement of neutron streaming through the fission gas plenum region, were analyzed using Monte Carlo and two-dimensional discrete ordinated methods. Calculated results compared well with measured results in many cases, although results were consistently underpredicted for the shorter plenum configurations. Like the measured data, the calculated results indicated no significant streaming when results from the heterogeneous mockups were compared to those from the homogeneous mockups. An explanation is given as to why little streaming was observed. The Hornyak button dose rates were overpredicted because of a normalization problem with the response function but yielded horizontal traverse curves whose shapes agreed well with the measured shapes to the same extent as did those for the other integral detectors. 16 refs., 16 figs., 4 tabs.

Slater, C.O.

1990-05-01T23:59:59.000Z

334

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

SciTech Connect (OSTI)

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

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

2011-01-14T23:59:59.000Z

335

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

SciTech Connect (OSTI)

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.

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

336

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

SciTech Connect (OSTI)

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.

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

337

Measurement of lanthanum and technetium in uranium fuels by inductively coupled plasma atomic emission spectroscopy.  

SciTech Connect (OSTI)

An important parameter in characterizing an irradiated nuclear fuel is determining the amount of uranium fissioned. By determining the amount of uranium fissioned in the fuel a burnup performance parameter can be calculated, and the amount of fission products left in the fuel can be predicted. The quantity of uranium fissioned can be calculated from the amount of lanthanum and technetium present in the fuel. Lanthanum and technetium were measured in irradiated fuel samples using an Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) instrument and separation equipment located in a shielded glove-box. A discussion of the method, interferences, detection limits, quality control and a comparison to other work will be presented.

Carney, K.; Crane, P.; Cummings, D.; Krsul, J.; McKnight, R.

1999-06-10T23:59:59.000Z

338

Photoabsorption by Ions and Atoms  

SciTech Connect (OSTI)

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.

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

2004-12-01T23:59:59.000Z

339

Realization of a superconducting atom chip  

E-Print Network [OSTI]

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.

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

2006-10-09T23:59:59.000Z

340

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

SciTech Connect (OSTI)

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).

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

2011-11-07T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

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]

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

Rathbun, Julie A.

342

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

DOE Patents [OSTI]

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.

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

1997-01-01T23:59:59.000Z

343

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

DOE Patents [OSTI]

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.

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

1997-12-16T23:59:59.000Z

344

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

SciTech Connect (OSTI)

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.

Baker, C.C.

1988-08-01T23:59:59.000Z

345

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

SciTech Connect (OSTI)

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.

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

346

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

SciTech Connect (OSTI)

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.

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

347

Role of atomic collisions in fusion  

SciTech Connect (OSTI)

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.

Post, D.E.

1982-04-01T23:59:59.000Z

348

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

SciTech Connect (OSTI)

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.

Jeffcoat, R.

2012-06-05T23:59:59.000Z

349

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

SciTech Connect (OSTI)

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.

Chou, Jason

2014-04-03T23:59:59.000Z

350

Characterization of the Radiation Shielding Properties of US andRussian EVA Suits  

SciTech Connect (OSTI)

Reported herein are results from the Eril Research, Inc.(ERI) participationin the NASA Johnson Space Center sponsored studycharacterizing the radiation shielding properties of the two types ofspace suit that astronauts are wearing during the EVA on-orbit assemblyof the International Space Station (ISS). Measurements using passivedetectors were carried out to assess the shielding properties of the USEMU Suit and the Russian Orlan-M suit during irradiations of the suitsand a tissue equivalent phantom to monoenergetic proton and electronbeams at the Loma Linda University Medical Center (LLUMC). Duringirradiations of 6 MeV electrons and 60 MeV protons, absorbed dose as afunction of depth was measured using TLDs exposed behind swatches of thetwo suit materials and inside the two EVA helmets. Considerable reductionin electron dosewas measured behind all suit materials in exposures to 6MeV electrons. Slowing of the proton beam in the suit materials led to anincrease in dose measured in exposures to 60 MeV protons. During 232 MeVproton irradiations, measurements were made with TLDs and CR-39 PNTDs atfive organ locations inside a tissue equivalent phantom, exposed bothwith and without the two EVA suits. The EVA helmets produce a 13 to 27percent reduction in total dose and a 0 to 25 percent reduction in doseequivalent when compared to measurements made in the phantom head alone.Differences in dose and dose equivalent between the suit and non-suitirradiations forthe lower portions of the two EVA suits tended to besmaller. Proton-induced target fragmentation was found to be asignificant source of increased dose equivalent, especially within thetwo EVA helmets, and average quality factor inside the EMU and Orlan-Mhelmets was 2 to 14 percent greater than that measured in the barephantom head.

Benton, E.R.; Benton, E.V.; Frank, A.L.

2001-10-26T23:59:59.000Z

351

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

SciTech Connect (OSTI)

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.

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

352

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

ScienceCinema (OSTI)

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.

Chou, Jason

2014-07-22T23:59:59.000Z

353

Clearance for Radiation Shielding Procedure: 7.90 Created: 11/5/2013 Version: 1.0 Revised  

E-Print Network [OSTI]

residual radioactive contamination. B. Applicability/scope This policy applies to all facilities whose and pigs D. Procedures 1. Shielding used in a radiation work station may be contaminated with radioactive is considered to be free of contamination, and can be disposed of without regards to radioactive contamination

Jia, Songtao

354

Methane Emissions from a Small Wind Shielded Lake Determined by Eddy Covariance, Flux Chambers, Anchored Funnels, and Boundary  

E-Print Network [OSTI]

Methane Emissions from a Small Wind Shielded Lake Determined by Eddy Covariance, Flux Chambers of methane, held to be responsible for 18% of the radiative forcing, to the atmosphere. Periods of lake but potentially one of the most important periods for methane emissions. We studied methane emissions using four

Wehrli, Bernhard

355

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

E-Print Network [OSTI]

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

Aalberts, Daniel P.

356

Driven Ratchets for Cold Atoms  

E-Print Network [OSTI]

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.

Renzoni, F

2011-01-01T23:59:59.000Z

357

Driven Ratchets for Cold Atoms  

E-Print Network [OSTI]

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.

F. Renzoni

2011-12-05T23:59:59.000Z

358

Single Atoms on an Optical Nanofiber  

E-Print Network [OSTI]

We show that single-atoms can be trapped on the surface of a subwavelength-diameter silica-fiber, an optical nanofiber, without any external field, and that single photons spontaneously emitted from the atoms can be readily detected through the single guided-mode of the nanofiber. A key point of the work is our finding that atom trapping sites are created on the nanofiber surface by irradiating the atom cloud around the nanofiber with a violet laser radiation.

Nayak, K P

2007-01-01T23:59:59.000Z

359

Single Atoms on an Optical Nanofiber  

E-Print Network [OSTI]

We show that single-atoms can be trapped on the surface of a subwavelength-diameter silica-fiber, an optical nanofiber, without any external field, and that single photons spontaneously emitted from the atoms can be readily detected through the single guided-mode of the nanofiber. A key point of the work is our finding that atom trapping sites are created on the nanofiber surface by irradiating the atom cloud around the nanofiber with a violet laser radiation.

K. P. Nayak; K. Hakuta

2007-09-18T23:59:59.000Z

360

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...

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Towards a high-precision atomic gyroscope  

E-Print Network [OSTI]

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

Van Camp, Mackenzie A. (Mackenzie Anne)

2013-01-01T23:59:59.000Z

362

Shielding and criticality analyses of phase I reference truck and rail cask designs for spent nuclear fuel  

SciTech Connect (OSTI)

Results are presented herein to determine the adequacy with respect to shielding regulations of reference designs for a truck cask containing 2 PWR or 5 BWR assemblies of standard burnup (45 GWd/MTU for PWR, 40 GWd/MTU for BWR) and 1 PWR assembly with extended burnup (55 GWd/MTU). The study also includes reference and modified rail cask designs with projected payloads of 8, 10, or 12 PWR assemblies. The burnup/age trends are analyzed in one dimension for both Pb and depleted uranium (DU) gamma-ray shields. The results of the two-dimensional shielding analysis uphold the one-dimensional results as being an appropriate means of studying the burnup/age trends for the truck cask. These results show that the reference design for the Pb-shield truck cask is inadequate for all cases considered, while the DU-shield truck cask is capable of carrying the desired payloads. The one-dimensional shielding analysis results for the reference Pb and DU rail casks indicate substantial margins exist in the side doses for reasonable burnup/age combinations. For a Pb-cask configuration, margins exist primarily for long-cooled (15 years) fuel. For the modified Pb and DU rail casks, the 2-m dose rates offer substantial margins below the regulatory limits for all burnup values considered provided the spent fuel has cooled for {>=}10 years. The modified Pb and DU casks yield essentially identical results and, hence, could be considered equivalent from a shielding perspective. The criticality analyses that were performed indicate that a truck basket can be designed to provide an adequate subcritical margin for 2 PWR assemblies enriched to 5 wt%. While the 10- and 12- assembly rail cask designs are very close to the regulatory limit of 0.95 for k{sub eff}, after accounting for a 0.01 {Delta}k bias and 2 standard deviations, the limit is exceeded by about 3%. It is believed that a combination of decreased enrichments and/or increased water gaps should allow these baskets to be acceptable.

Broadhead, B.L.; Childs, R.L.; Parks, C.V.

1996-03-01T23:59:59.000Z

363

Shielded Payload Containers Will Enhance the Safety and Efficiency of the DOE's Remote Handled Transuranic Waste Disposal Operations  

SciTech Connect (OSTI)

The Waste Isolation Pilot Plant (WIPP) disposal operation currently employs two different disposal methods: one for Contact Handled (CH) waste and another for Remote Handled (RH) waste. CH waste is emplaced in a variety of payload container configurations on the floor of each disposal room. In contrast, RH waste is packaged into a single type of canister and emplaced in pre-drilled holes in the walls of disposal rooms. Emplacement of the RH waste in the walls must proceed in advance of CH waste emplacement. This poses a significant logistical constraint on waste handling operations by requiring significant coordination between waste characterization and preparations for shipping among the various generators. To improve operational efficiency, the Department of Energy (DOE) is proposing a new waste emplacement process for certain RH waste streams that can be safely managed in shielded containers. RH waste with relatively low gamma-emitting activity would be packaged in lead-lined containers, shipped to WIPP in existing certified transportation packages for CH waste, and emplaced in WIPP among the stacks of CH waste containers on the floor of a disposal room. RH waste with high gamma-emitting activity would continue to be emplaced in the boreholes along the walls. The new RH container appears essentially the same as a nominal 208-liter drum, but is built with about 2.5 cm of lead, sandwiched between thick steel sheet. The top and bottom are made of very thick plate steel, for strengthening the package to meet transportation requirements, and provide similar gamma attenuation. This robust configuration provides an overpack for waste that otherwise would be remotely handled. Up to a 3:1 reduction in number of shipments is projected if RH waste were transported in the proposed shielded containers. This paper describes the container design and testing, as well as the regulatory approach used to meet the requirements that apply to WIPP and its associated transportation system. This paper describes the RH transuranic waste inventory that may be candidates for packaging and emplacement in shielded containers. DOE does not propose to use shielded containers to increase the amount of RH waste allowed at WIPP. DOE's approach to gain approval for the transportation of shielded containers and to secure regulatory approval for use of shielded containers from WIPP regulators is discussed. Finally, the paper describes how DOE proposes to count the waste packaged into shielded containers against the RH waste inventory and how this will comply with the volume and radioactivity limitations imposed in the many and sometimes overlapping regulations that apply to WIPP. (authors)

Nelson, R.A. [U. S. Department of Energy, Carlsbad, New Mexico (United States); White, D.S. [Washington Group International, Carlsbad, New Mexico (United States)

2008-07-01T23:59:59.000Z

364

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

SciTech Connect (OSTI)

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.

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

2005-06-01T23:59:59.000Z

365

The Future of Atomic Energy  

DOE R&D Accomplishments [OSTI]

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.

Fermi, E.

1946-05-27T23:59:59.000Z

366

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 on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy Resources Jump to: navigation, searchGeauga County, Ohio: Energy Resources Jump to:GenabilityAtomics Jump

367

Gauge invariant hydrogen atom Hamiltonian  

E-Print Network [OSTI]

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.

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

2010-06-22T23:59:59.000Z

368

Atoms, photons, and Information Andrew Silberfarb  

E-Print Network [OSTI]

Atoms, photons, and Information by Andrew Silberfarb B.S. California Institute of Technology, 1998 #12;Atoms, photons, and Information by Andrew Silberfarb ABSTRACT OF DISSERTATION Submitted in Partial Albuquerque, New Mexico March, 2006 #12;Atoms, photons, and Information by Andrew Silberfarb B.S. California

Deutsch, Ivan H.

369

Stark spectroscopy on rare gas atoms  

E-Print Network [OSTI]

Stark spectroscopy on rare gas atoms PROEFSCHRIFT ter verkrijging van de graad van doctor aan de-DATA LIBRARY TECHNISCHE UNIVERSITEIT EINDHOVEN Jiang, Tao Stark spectroscopy on rare gas atoms / by Tao Jiang / gasontladingen Subject headings : plasma diagnostics / Stark effect / optogalvanic spectroscopy / atomic emission

Eindhoven, Technische Universiteit

370

Sources of polarized ions and atoms  

SciTech Connect (OSTI)

In this presentation we discuss methods of producing large quantities of polarized atoms and ions (Stern-Gerlach separation, optical pumping, and spin-exchange) as well as experimental methods of measuring the degree of polarization of atomic systems. The usefulness of polarized atoms in probing the microscopic magnetic surface properties of materials will also be discussed. 39 refs., 5 figs., 2 tabs.

Cornelius, W.D.

1988-01-01T23:59:59.000Z

371

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...

372

Self-corrected Sensors Based On Atomic Absorption Spectroscopy...  

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

corrected Sensors Based On Atomic Absorption Spectroscopy For Atom Flux Measurements In Molecular Beam Epitaxy. Self-corrected Sensors Based On Atomic Absorption Spectroscopy For...

373

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...

374

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...

375

Understanding Atom Probe Tomography of Oxide-Supported Metal...  

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

Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Understanding Atom Probe Tomography of Oxide-Supported Metal...

376

Cooling and Trapping Atoms Atoms are slowed and cooled by radiation pressure from laser light  

E-Print Network [OSTI]

Cooling and Trapping Atoms Atoms are slowed and cooled by radiation pressure from laser light and then trapped in a bottle whose "walls" are magnetic fields. Cooled atoms are ideal for exploring basic. research has traditionally been the study of the intrinsic prop erties of isolated atoms. In the early part

Johannesson, Henrik

377

Atomic flux measurement by diode-laser-based atomic absorption spectroscopy  

E-Print Network [OSTI]

Atomic flux measurement by diode-laser-based atomic absorption spectroscopy Weizhi Wang,a) R. H, California 94305 Received 5 May 1999; accepted 6 June 1999 Diode-laser-based atomic absorption AA sensors- quirements, and only the QCM measures the flux. Lamp- based atomic absorption AA sensors have been success

Fejer, Martin M.

378

NAAP Hydrogen Atom 1/9 The Hydrogen Atom Student Guide  

E-Print Network [OSTI]

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

Farritor, Shane

379

Atomic Structure Calculations from the Los Alamos Atomic Physics Codes  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

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.

Cowan, R. D.

380

Dynamics of Tilt-based Browsing on Mobile Devices  

E-Print Network [OSTI]

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

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

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Hydrogen Atom in Relativistic Motion  

E-Print Network [OSTI]

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.

M. Jarvinen

2005-04-11T23:59:59.000Z

382

Atoms can be divided into three categories: polar, non-polar and hydrogen atom  

E-Print Network [OSTI]

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).

Pei-Lin You

2010-10-10T23:59:59.000Z

383

Shielding Experiments Under JASMIN Collaboration at Fermilab(III) - Measurement of High-Energy Neutrons Penetrating a Thick Iron Shield from the Antiproton Production Target by AU Activation Method  

E-Print Network [OSTI]

In an antiproton production (Pbar) target station of the Fermi National Accelerator Laboratory (FNAL), the secondary particles produced by bombarding a target with 120-GeV protons are shielded by a thick iron shield. In order to obtain experimental data on high-energy neutron transport at more than 100-GeV-proton accelerator facilities, we indirectly measured more than 100-MeV neutrons at the outside of the iron shield at an angle of 50{\\deg} in the Pbar target station. The measurement was performed by using the Au activation method coupled with a low-background {\\gamma}-ray counting system. As an indicator for the neutron flux, we determined the production rates of 8 spallation nuclides (196-Au, 188-Pt, 189-Ir, 185-Os, 175-Hf, 173-Lu, 171-Lu, and 169-Yb) in the Au activation detector. The measured production rates were compared with the theoretical production rates calculated using PHITS. We proved that the Au activation method can serve as a powerful tool for indirect measurements of more than 100-MeV neutrons that play a vital role in neutron transport. These results will be important for clarifying the problems in theoretical calculations of high-energy neutron transport.

H. Matsumura; N. Kinoshita; H. Iwase; A. Toyoda; Y. Kasugai; N. Matsuda; Y. Sakamoto; H. Nakashima; H. Yashima; N. Mokhov; A. Leveling; D. Boehlein; K. Vaziri; G. Lautenschlager; W. Schmitt; K. Oishi

2012-05-01T23:59:59.000Z

384

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

SciTech Connect (OSTI)

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.

Sheryl L. Morton; Philip L. Winston; Toshiari Saegusa; Koji Shirai; Akihiro Sasahara; Takatoshi Hattori

2006-04-01T23:59:59.000Z

385

Characterizing the Star Formation of the Low-Mass SHIELD Galaxies from Hubble Space Telescope Imaging  

E-Print Network [OSTI]

The Survey of HI in Extremely Low-mass Dwarfs (SHIELD) is an on-going multi-wavelength program to characterize the gas, star formation, and evolution in gas-rich, very low-mass galaxies that populate the faint end of the galaxy luminosity function. The galaxies were selected from the first ~10% of the HI ALFALFA survey based on their low HI mass and low baryonic mass. Here, we measure the star-formation properties from optically resolved stellar populations for 12 galaxies using a color-magnitude diagram fitting technique. We derive lifetime average star-formation rates (SFRs), recent SFRs, stellar masses, and gas fractions. Overall, the recent SFRs are comparable to the lifetime SFRs with mean birthrate parameter of 1.4, with a surprisingly narrow standard deviation of 0.7. Two galaxies are classified as dwarf transition galaxies (dTrans). These dTrans systems have star-formation and gas properties consistent with the rest of the sample, in agreement with previous results that some dTrans galaxies may simply...

McQuinn, Kristen B W; Dolphin, Andrew E; Skillman, Evan D; Haynes, Martha P; Simones, Jacob E; Salzer, John J; Adams, Elizabeth A K; Elson, Ed C; Giovanelli, Riccardo; Ott, Jürgen

2015-01-01T23:59:59.000Z

386

Processes, Techniques, and Successes in Welding the Dry Shielded Canisters of the TMI-2 Reactor Core Debris  

SciTech Connect (OSTI)

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.

Zirker, L.R.; Rankin, R.A.; Ferrell, L.J.

2002-01-29T23:59:59.000Z

387

An output coupler for Bose condensed atoms The observations of BEC have stimulated interest in atom lasers, coherent sources of  

E-Print Network [OSTI]

An output coupler for Bose condensed atoms The observations of BEC have stimulated interest in atom lasers, coherent sources of atomic matter waves. The build-up of atoms in the ground state of a magnetic. We demonstrated a scheme for doing this with Bose condensed atoms [1]. A variable fraction of atoms

388

The new solid target system at UNAM in a self-shielded 11 MeV cyclotron  

SciTech Connect (OSTI)

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.

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

389

Constraints on target chamber first wall and target designs that will enable NIF debris shields to survive  

SciTech Connect (OSTI)

The National Ignition Facility target chamber interior materials and target designs themselves have to be compatible with survival of the final-optics debris shields. To meet the planned maintenance and refinishing rate, the contamination of the debris shields cannot exceed about 1 nm equivalent thickness per shot of total material. This implies that the target mass must be limited to no more than 1 gram and the ablated mass released to the chamber from all other components must not exceed 3 grams. In addition, the targets themselves must either completely vaporize or send any minor amounts of shrapnel towards the chamber waist to prevent excessive cratering of the debris shields. The constraints on the first-wall ablation require that it be louvered to provide passive collection of remobilized contamination, because the expected target debris will remobilize at a rate fast enough to require cleaning every 3 weeks, about three times more frequent than possible with planned robotics. Furthermore, a comparison of ablatants from B{sub 4}C and stainless-steel louvers suggests that remobilization of target debris by x rays will be greater than of the base material in both cases, thereby reducing the performance advantage of clean B{sub 4}C over much-cheaper stainless steel. Neutronics calculations indicate that activation of thin Ni-free stainless steel is not a significant source of maintenance personnel radiation dose. Consequently, the most attractive first wall design consists of stainless-steel louvers. Evaluation of various unconverted-light beam dump designs indicates that stainless steel louvers generate no more debris than other materials, so one single design can serve as both first wall and beam dumps, eliminating beam steering restrictions caused by size and location of the beam dumps. One reservation is that the allowable contamination rate of the debris shield is not yet completely understood.

Hibbard,W.; Burnham, A. K.; Curran, D. R; Genin, F. Y.; Gerassimenko, M.; Latkowski, J. F.; Peterson, P. F.; Scott, J. M.; Tokheim, R. E.; Whitman, P. K.

1998-07-09T23:59:59.000Z

390

Safety evaluation for packaging (onsite) for the concrete-shielded RH TRU drum for the 327 Postirradiation Testing Laboratory  

SciTech Connect (OSTI)

This safety evaluation for packaging authorizes onsite transport of Type B quantities of radioactive material in the Concrete Shielded Remote-Handled Transuranic Waste (RH TRU) Drum per HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments. The drum will be used for transport of 327 Building legacy waste from the 300 Area to a solid waste storage facility on the Hanford Site.

Smith, R.J.

1998-03-31T23:59:59.000Z

391

Phases of Atom-Molecule Vortex Matter  

SciTech Connect (OSTI)

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.

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

392

Field application of EMI coatings investigation of coating materials and stylus electroplating protocols for shielded facilities. Final report  

SciTech Connect (OSTI)

To maintain reliable electromagnetic interference (EMI) shielding for electronic equipment shelter interfaces, mating surfaces such as doors and interfaces must provide low contact resistances and be resistant to excessive amounts of corrosion and mechanical wear that would tend to degrade their shielding integrity. The objective of this research was to establish the efficacy of stylus electroplating as a potentially viable field maintenance/repair technique for application of corrosion resistant, wear resistant coatings in order to help maintain the shielding integrity of those interfaces. Aluminum alloy (6061-T6) knife-edge and channel test pieces were stylus electroplated with tin or tin-lead coatings with nickel or copper underlayers. A custom-designed electroplating tool developed for electroplating the complex geometry of a knife-edge substrate appears to provide better control of the plating process and circumvents possible interference with previously deposited areas. This research has resulted in an optimized procedure for producing coatings that exhibit greater adherence, better uniformity, less scarring, and fewer blisters and ridges compared to those previously reported. An optimum electroplating strategy is suggested, which includes applying tin or tin-lead top layers over a thick layer of copper and a thin nickel strike.

Stephenson, L.D.; Donoho, L.H.

1996-03-01T23:59:59.000Z

393

Gas Atomization of Stainless Steel - Slow Motion  

SciTech Connect (OSTI)

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

None

2011-01-01T23:59:59.000Z

394

Interfacing ultracold atoms and mechanical oscillators.  

E-Print Network [OSTI]

??In this thesis I present experiments investigating controlled coupling between mechanical oscillators and ultracold atoms. I report on three different coupling mechanisms. In a first… (more)

Camerer, Stephan

2011-01-01T23:59:59.000Z

395

Cold collisions of Rb and Cs atoms  

E-Print Network [OSTI]

Jamieson,M.J. Sarbazi-Azad,H. 18'th International Conference on Atomic Physics, MIT, Cambridge, MA, USA Academic Press

Jamieson, M.J.

396

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. ...

397

Classical and Quantum Chaos in Atom Optics  

E-Print Network [OSTI]

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.

Farhan Saif

2006-04-10T23:59:59.000Z

398

Using Atomic Clocks to Detect Gravitational Waves  

E-Print Network [OSTI]

Atomic clocks have recently reached a fractional timing precision of $test masses separated by less than a GW wavelength, currently envisioned for the eLISA mission.

Loeb, Abraham

2015-01-01T23:59:59.000Z

399

Ps-atom scattering at low energies  

E-Print Network [OSTI]

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 $venergy region, in contrast to the inter...

Fabrikant, I I

2015-01-01T23:59:59.000Z

400

Directly correlated transmission electron microscopy and atom...  

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

Directly correlated transmission electron microscopy and atom probe tomography of grain boundary oxidation in a Ni-Al binary Directly correlated transmission electron microscopy...

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

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]

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...

DeVore, Robin Kent

1973-01-01T23:59:59.000Z

402

CARBON ATOM DISTRIBUTION IN A DUAL PHASE STEEL: AN ATOM PROBE STUDY  

E-Print Network [OSTI]

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

Barnard, S.J.

2014-01-01T23:59:59.000Z

403

Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material  

SciTech Connect (OSTI)

Stress corrosion cracking is one of the most common corrosion-related causes for premature breach of metal structural components. Stress corrosion cracking is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously: metallurgical susceptibility, critical environment, and static (or sustained) tensile stresses. This report was prepared according to ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of this report is to provide an evaluation of the potential for stress corrosion cracking of the engineered barrier system components (i.e., the drip shield, waste package outer barrier, and waste package stainless steel inner structural cylinder) under exposure conditions consistent with the repository during the regulatory period of 10,000 years after permanent closure. For the drip shield and waste package outer barrier, the critical environment is conservatively taken as any aqueous environment contacting the metal surfaces. Appendix B of this report describes the development of the SCC-relevant seismic crack density model (SCDM). The consequence of a stress corrosion cracking breach of the drip shield, the waste package outer barrier, or the stainless steel inner structural cylinder material is the initiation and propagation of tight, sometimes branching, cracks that might be induced by the combination of an aggressive environment and various tensile stresses that can develop in the drip shields or the waste packages. The Stainless Steel Type 316 inner structural cylinder of the waste package is excluded from the stress corrosion cracking evaluation because the Total System Performance Assessment for License Application (TSPA-LA) does not take credit for the inner cylinder. This document provides a detailed description of the process-level models that can be applied to assess the performance of Alloy 22 (used for the waste package outer barrier) and Titanium Grade 7 (used for the drip shield) that are subjected to the effects of stress corrosion cracking. The use of laser peening or other residual stress mitigation techniques is considered as a means of mitigating stress corrosion cracking in the waste package final closure lid weld.

G. Gordon

2004-10-13T23:59:59.000Z

404

Optical control of ground-state atomic orbital alignment: Cl,,2 P3/2... atoms  

E-Print Network [OSTI]

Optical control of ground-state atomic orbital alignment: Cl,,2 P3/2... atoms from HCl,,v=2,J=1-of-flight mass spectrometry. The 35 Cl 2 P3/2 atoms are aligned by two mechanisms: 1 the time-dependent transfer is conserved during the photodissociation and thus contributes to the total 35 Cl 2 P3/2 photofragment atomic

Zare, Richard N.

405

Radiation embrittlement of the neutron shield tank from the Shippingport reactor  

SciTech Connect (OSTI)

The irradiation embrittlement of neutron shield tank (NST) material (A212 Grade B steel) from the Shippingport reactor has been characterized. Irradiation increases the Charpy transition temperature (CTT) by 23--28{degrees}C (41--50{degrees}F) and decreases the upper-shelf energy. The shift in CTT is not as severe as that observed in high-flux isotope reactor (HFIR) surveillance specimens. However, the actual value of the CTT is higher than that for the HFIR data. The increase in yield stress is 51 MPa (7.4 ksi), which is comparable to HFIR data. The NST material is weaker in the transverse orientation than in the longitudinal orientation. Some effects of position across the thickness of the wall are also observed; the CTT shift is slightly greater for specimens from the inner region of the wall. Annealing studies indicate complete recovery from embrittlement after 1 h at 400{degrees}C (752{degrees}F). Although the weld metal is significantly tougher than the base metal, the shifts in CTT are comparable. The shifts in CTT for the Shippingport NST are consistent with the test and Army reactor data for irradiations at <232{degrees}C (<450{degrees}F) and show very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor (ORR). The effects of irradiation temperature, fluence rate, and neutron flux spectrum are discussed. The results indicate that fluence rate has no effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center dot}s and at the low operating temperatures of the Shippingport NST, i.e., 55{degrees}C (130{degrees}F). This suggests that the accelerated embrittlement of HFIR surveillance samples is most likely due to the relatively higher proportion of thermal neutrons in the HFIR spectrum compared to that for the test reactors. 28 refs., 25 figs.

Chopra, O.K.; Shack, W.J. (Argonne National Lab., IL (United States)); Rosinski, S.T. (Sandia National Labs., Albuquerque, NM (United States))

1991-10-01T23:59:59.000Z

406

Calculation of shielding door thicknesses for radiation therapy facilities using the ITS Monte Carlo program  

SciTech Connect (OSTI)

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.

Biggs, P.J. (Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston (United States))

1991-10-01T23:59:59.000Z

407

Photoassociative molecular spectroscopy for atomic radiative lifetimes.  

E-Print Network [OSTI]

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

Boyer, Edmond

408

so Ris Report * Danish Atomic Energy Commission  

E-Print Network [OSTI]

in Bitumen of Low-Level Radioactive Waste Water Evaporator Concentrate at the Danish Atomic Energy Com Incorporation in Bitumen of Low-Level Radioactive Waste Water Evaporator Concentrate at the Danish Atomic Energy Risø Chemistry Department Abstract The plant for evaporation of radioactive waste water at the Research

409

Hartree-Fock theory for pseudorelativistic atoms  

E-Print Network [OSTI]

We study the Hartree-Fock model for pseudorelativistic atoms, that is, atoms where the kinetic energy of the electrons is given by the pseudorelativistic operator \\sqrt{(pc)^2+(mc^2)^2}-mc^2. We prove the existence of a Hartree-Fock minimizer, and prove regularity away from the nucleus and pointwise exponential decay of the corresponding orbitals.

Anna Dall'Acqua; Thomas Østergaard Sørensen; Edgardo Stockmeyer

2007-07-31T23:59:59.000Z

410

Formation of $??$ atoms in $K_{?4} decay  

E-Print Network [OSTI]

We derive the decay rate of $\\pi\\mu$ atom formation in $K_{\\mu 4}$ decay. Using the obtained expressions we calculate the decay rate of atom formation and point out that considered decay can give a noticeable contribution as a background to the fundamental decay $K^+\\to \\pi^+\

S. R. Gevorkyan; A. V. Tarasov; O. O. Voskresenskaya

2009-12-01T23:59:59.000Z

411

Atomic processes in high-density plasmas  

SciTech Connect (OSTI)

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)

More, R.M.

1982-12-21T23:59:59.000Z

412

Relativistic atomic physics at the SSC  

SciTech Connect (OSTI)

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.

NONE

1990-12-31T23:59:59.000Z

413

Quantum Computing with Atomic Josephson Junction Arrays  

E-Print Network [OSTI]

We present a quantum computing scheme with atomic Josephson junction arrays. The system consists of a small number of atoms with three internal states and trapped in a far-off resonant optical lattice. Raman lasers provide the "Josephson" tunneling, and the collision interaction between atoms represent the "capacitive" couplings between the modes. The qubit states are collective states of the atoms with opposite persistent currents. This system is closely analogous to the superconducting flux qubit. Single qubit quantum logic gates are performed by modulating the Raman couplings, while two-qubit gates result from a tunnel coupling between neighboring wells. Readout is achieved by tuning the Raman coupling adiabatically between the Josephson regime to the Rabi regime, followed by a detection of atoms in internal electronic states. Decoherence mechanisms are studied in detail promising a high ratio between the decoherence time and the gate operation time.

Lin Tian; P. Zoller

2003-06-12T23:59:59.000Z

414

Quantum computing with atomic Josephson junction arrays  

SciTech Connect (OSTI)

We present a quantum computing scheme with atomic Josephson junction arrays. The system consists of a small number of atoms with three internal states and trapped in a far-off-resonant optical lattice. Raman lasers provide the 'Josephson' tunneling, and the collision interaction between atoms represent the 'capacitive' couplings between the modes. The qubit states are collective states of the atoms with opposite persistent currents. This system is closely analogous to the superconducting flux qubit. Single-qubit quantum logic gates are performed by modulating the Raman couplings, while two-qubit gates result from a tunnel coupling between neighboring wells. Readout is achieved by tuning the Raman coupling adiabatically between the Josephson regime to the Rabi regime, followed by a detection of atoms in internal electronic states. Decoherence mechanisms are studied in detail promising a high ratio between the decoherence time and the gate operation time.

Tian Lin; Zoller, P. [Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

2003-10-01T23:59:59.000Z

415

Quantum-noise quenching in atomic tweezers  

SciTech Connect (OSTI)

The efficiency of extracting single atoms or molecules from an ultracold bosonic reservoir is theoretically investigated for a protocol based on lasers, coupling the hyperfine state in which the atoms form a condensate to another stable state, in which the atom experiences a tight potential in the regime of collisional blockade, the quantum tweezers. The transfer efficiency into the single-atom ground state of the tight trap is fundamentally limited by the collective modes of the condensate, which are thermally and dynamically excited. The noise due to these excitations can be quenched for sufficiently long laser pulses, thereby achieving high efficiencies. These results show that this protocol can be applied to initializing a quantum register based on tweezer traps for neutral atoms.

Zippilli, Stefano [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Theoretische Physik, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany); Fachbereich Physik and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany); Mohring, Bernd; Schleich, Wolfgang [Institut fuer Quantenphysik, Universitaet Ulm, D-89081 Ulm (Germany); Lutz, Eric [Department of Physics, University of Augsburg, D-86135 Augsburg (Germany); Morigi, Giovanna [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Theoretische Physik, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany)

2011-05-15T23:59:59.000Z

416

Quantum-noise quenching in atomic tweezers  

E-Print Network [OSTI]

The efficiency of extracting single atoms or molecules from an ultracold bosonic reservoir is theoretically investigated for a protocol based on lasers, coupling the hyperfine state in which the atoms form a condensate to another stable state, in which the atom experiences a tight potential in the regime of collisional blockade, the quantum tweezers. The transfer efficiency into the single-atom ground state of the tight trap is fundamentally limited by the collective modes of the condensate, which are thermally and dynamically excited. The noise due to these excitations can be quenched for sufficiently long laser pulses, thereby achieving high efficiencies. These results show that this protocol can be applied for initializing a quantum register based on tweezer traps for neutral atoms.

Stefano Zippilli; Bernd Mohring; Eric Lutz; Giovanna Morigi; Wolfgang Schleich

2011-04-15T23:59:59.000Z

417

Teleportation of an atomic momentum state  

E-Print Network [OSTI]

. The momentum state that is to be transferred is defined as uCa&5cau1p0&1cbu2p0&, ~1! FIG. 1. Schematic diagram of the quantum controlled-NOT logic gate used for the atomic momentum state teleportation. If p0 is the moment of the incoming atom along the x... of atomic center-of-mass momentum m controlled-NOT gate via atomic scattering in the PACS number~s!: 03.67.2a, 42.50.Ct, 32.80.Qk where u1p0& and u2p0& are the momentum states of the incoming atoms in 6x directions, respectively ~see Fig. 1! and ca...

Qamar, S.; Zhu, S. Y.; Zubairy, M. Suhail.

2003-01-01T23:59:59.000Z

418

Laser trapping of {sup 21}Na atoms  

SciTech Connect (OSTI)

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.

Lu, Zheng-Tian

1994-09-01T23:59:59.000Z

419

Atomic magnetometer for human magnetoencephalograpy.  

SciTech Connect (OSTI)

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.

Schwindt, Peter; Johnson, Cort N.

2010-12-01T23:59:59.000Z

420

On the energy of electric field in hydrogen atom  

E-Print Network [OSTI]

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.

Yuri Kornyushin

2009-07-30T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Alternatives evaluation and decommissioning study on shielded transfer tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee  

SciTech Connect (OSTI)

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.

DeVore, J.R.; Hinton, R.R.

1994-08-01T23:59:59.000Z

422

Synthesis of zinc oxide particles coated multiwalled carbon nanotubes: Dielectric properties, electromagnetic interference shielding and microwave absorption  

SciTech Connect (OSTI)

Graphical abstract: A resistor–capacitor model could well describe the relationships between the structure and the dielectric properties, electromagnetic interference shielding and microwave-absorption of the composites in the frequency range of 2–18 GHz. The resonant behavior associated with the multiwalled carbon nanotubes/zinc oxide (MWCNTs/ZnO) interface greatly broadens the absorption band. Highlights: ? ZnO-immobilized on multiwalled carbon nanotubes (MWCNTs/ZnO) have resonant behavior. ? A resistor–capacitor model describes the relation between the structure and properties. ? The composite with 40 wt% MWCNTs/ZnO has good electromagnetic interference shielding. ? Two different types of absorption peaks are found in the MWCNTs/ZnO composites. ? The existence of MWCNTs/ZnO interface broadens the absorption band. -- Abstract: Zinc oxide (ZnO) nanoparticles were coated on the surfaces of multiwalled carbon nanotubes (MWCNTs). High resolution transmission electron microscopy images show that the wurtzite ZnO immobilized on the MWCNTs is single-crystalline with a preferential [0 0 0 2] growth direction. A capacitor was generated by the interface of ZnO and MWCNTs, and a resistor–capacitor model could well describe the relationships between the structure and the dielectric properties, electromagnetic interference shielding and microwave-absorption of the composites in the frequency range of 2–18 GHz. The network built by ZnO-immobilized MWCNTs could contribute to the improvement of electrical properties. Resonant peaks associated with the capacitor formed by the interface were observed in the microwave absorption spectra, which suggest that reflection–loss peaks greatly broadens the absorption bandwidth.

Song, Wei-Li [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)] [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Cao, Mao-Sheng, E-mail: caomaosheng@bit.edu.cn [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)] [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Wen, Bo; Hou, Zhi-Ling; Cheng, Jin [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)] [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Yuan, Jie, E-mail: yuanjie4000@sina.com [School of Information Engineering, Central University for Nationality, Beijing 100081 (China)] [School of Information Engineering, Central University for Nationality, Beijing 100081 (China)

2012-07-15T23:59:59.000Z

423

The dressed mobile atoms and ions  

E-Print Network [OSTI]

We consider free atoms and ions in $\\R^3$ interacting with the quantized electromagnetic field. Because of the translation invariance we consider the reduced hamiltonian associated with the total momentum. After introducing an ultraviolet cutoff we prove that the reduced hamiltonian for atoms has a ground state if the coupling constant and the total momentum are sufficiently small. In the case of ions an extra infrared regularization is needed. We also consider the case of the hydrogen atom in a constant magnetic field. Finally we determine the absolutely continuous spectrum of the reduced hamiltonian.

Laurent Amour; Benoit Grebert; Jean-Claude Guillot

2005-07-20T23:59:59.000Z

424

An Atom Trap Relying on Optical Pumping  

E-Print Network [OSTI]

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.

P. Bouyer; P. Lemonde; M. Ben Dahan; A. Michaud; C. Salomon; J. Dalibard

2005-09-21T23:59:59.000Z

425

Nanoscale atomic waveguides with suspended carbon nanotubes  

E-Print Network [OSTI]

We propose an experimentally viable setup for the realization of one-dimensional ultracold atom gases in a nanoscale magnetic waveguide formed by single doubly-clamped suspended carbon nanotubes. We show that all common decoherence and atom loss mechanisms are small guaranteeing a stable operation of the trap. Since the extremely large current densities in carbon nanotubes are spatially homogeneous, our proposed architecture allows to overcome the problem of fragmentation of the atom cloud. Adding a second nanowire allows to create a double-well potential with a moderate tunneling barrier which is desired for tunneling and interference experiments with the advantage of tunneling distances being in the nanometer regime.

V. Peano; M. Thorwart; A. Kasper; R. Egger

2005-11-23T23:59:59.000Z

426

Storing images in warm atomic vapor  

E-Print Network [OSTI]

Reversible and coherent storage of light in atomic medium is a key-stone of future quantum information applications. In this work, arbitrary two-dimensional images are slowed and stored in warm atomic vapor for up to 30 $\\mu$s, utilizing electromagnetically induced transparency. Both the intensity and the phase patterns of the optical field are maintained. The main limitation on the storage resolution and duration is found to be the diffusion of atoms. A techniqueanalogous to phase-shift lithography is employed to diminish the effect of diffusion on the visibility of the reconstructed image.

M. Shuker; O. Firstenberg; R. Pugatch; A. Ron; N. Davidson

2008-06-17T23:59:59.000Z

427

Single atom as a macroscopic entanglement source  

E-Print Network [OSTI]

by many authors including the generation of entangled coherent state #3;1?3#4;, single photon and vacuum entanglement #3;4#4;, and two-atom entanglement #3;5#4;. More recently, generation of macroscopic entangled states via phase sensitive... cascade configuration crossing or trapped in a two-mode field cavity. The atomic level configuration is depicted in Fig. 1. The two atomic transitions #5;a#6;? #5;b#6; and #5;b#6;? #5;c#6; interact with the two cavity modes with detunings #1...

Zhou, Ling; Xiong, Han; Zubairy, M. Suhail.

2006-01-01T23:59:59.000Z

428

The Manhattan Project: Making the atomic bomb  

SciTech Connect (OSTI)

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.

Gosling, F.G.

1994-09-01T23:59:59.000Z

429

Duality in spaces of finite linear combinations of atoms  

E-Print Network [OSTI]

Duality in spaces of finite linear combinations of atoms Fulvio Ricci and Joan Verdera Abstract In this note we describe the dual and the completion of the space of finite linear combinations of (p, )-atoms, )-atoms, 0

Ricci, Fulvio

430

CHARGE TRANSFER BETWEEN POSITIVE ALKALI IONS AND ATOMS  

E-Print Network [OSTI]

average velocity of atoms , ::. : . . :. . in the oven. Thisfor a potassium ", . atom beam operating under conditionsPOSITIVE ALKALI IONS AND ATOMS I W. R. Gentry, Yuan-tseh L e

Gentry, W.R.; Lee, Yuan-tseh; Mahan, Bruce H.

2008-01-01T23:59:59.000Z

431

Studying coherence in ultra-cold atomic gases  

E-Print Network [OSTI]

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 ...

Miller, Daniel E. (Daniel Edward)

2007-01-01T23:59:59.000Z

432

E-Print Network 3.0 - analytical atomic spectroscopy Sample Search...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission spectroscopy Atomic fluorescence...

433

E-Print Network 3.0 - atomic spectroscopy technologies Sample...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission spectroscopy Atomic fluorescence...

434

Interaction of an aluminum atom with a closed subshell metal atom: Spectroscopic analysis of AlZn  

E-Print Network [OSTI]

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

Morse, Michael D.

435

Single Supported Atoms Participate in Catalytic Processes | ornl...  

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

Functional Materials for Energy Single Supported Atoms Participate in Catalytic Processes December 04, 2014 Pathways for NO oxidation on single Pt atoms supported on the (010)...

436

Loading rubidium atoms into a hollow core fiber .  

E-Print Network [OSTI]

??We demonstrate a procedure for cooling, trapping, and transferring rubidium atoms into a hollow core photonic band gap fiber. The atoms are first collected in… (more)

Chu, Yiwen

2007-01-01T23:59:59.000Z

437

President Roosevelt Approves Production of Atomic Bomb | National...  

National Nuclear Security Administration (NNSA)

Atomic Bomb Washington, DC President Roosevelt approves production of the atomic bomb following receipt of a National Academy of Sciences report determining that a bomb is feasible...

438

Ab Initio Atomic Simulations of Antisite Pair Recovery in Cubic...  

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

Atomic Simulations of Antisite Pair Recovery in Cubic Silicon Carbide. Ab Initio Atomic Simulations of Antisite Pair Recovery in Cubic Silicon Carbide. Abstract: The thermal...

439

Atomic-Scale Simulations of Cascade Overlap and Damage Evolution...  

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

Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide. Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide. Abstract:...

440

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...

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

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...

442

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...

443

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...

444

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...

445

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...

446

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...

447

Electronic transport in atomically thin layered materials  

E-Print Network [OSTI]

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 ...

Baugher, Britton William Herbert

2014-01-01T23:59:59.000Z

448

Detecting Topological Phases in Cold Atoms  

E-Print Network [OSTI]

Chern insulators are band insulators which exhibit a gap in the bulk and gapless excitations in the edge. Detection of Chern insulators is a serious challenge in cold atoms since the Hall transport measurements are technically ...

Liu, Xiong-Jun

449

Atomic effect algebras with compression bases  

SciTech Connect (OSTI)

Compression base effect algebras were recently introduced by Gudder [Demonstr. Math. 39, 43 (2006)]. They generalize sequential effect algebras [Rep. Math. Phys. 49, 87 (2002)] and compressible effect algebras [Rep. Math. Phys. 54, 93 (2004)]. The present paper focuses on atomic compression base effect algebras and the consequences of atoms being foci (so-called projections) of the compressions in the compression base. Part of our work generalizes results obtained in atomic sequential effect algebras by Tkadlec [Int. J. Theor. Phys. 47, 185 (2008)]. The notion of projection-atomicity is introduced and studied, and several conditions that force a compression base effect algebra or the set of its projections to be Boolean are found. Finally, we apply some of these results to sequential effect algebras and strengthen a previously established result concerning a sufficient condition for them to be Boolean.

Caragheorgheopol, Dan [Department of Mathematics and Informatics, Technical University of Civil Engineering in Bucharest, 124 Lacul Tei blv., RO-020396 and 'Ilie Murgulescu' Institute of Physical Chemistry, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Tkadlec, Josef [Department of Mathematics, Faculty of Electrical Engineering, Czech Technical University in Prague, 166 27 Prague (Czech Republic)

2011-01-15T23:59:59.000Z

450

Testing Lorentz symmetry with atoms and Light  

E-Print Network [OSTI]

This article reports on the Fifth Meeting on CPT and Lorentz Symmetry, CPT'10, held at the end of June 2010 in Bloomington, Indiana, USA. The focus is on recent tests of Lorentz symmetry using atomic and optical physics.

Neil Russell

2011-09-04T23:59:59.000Z

451

Electrical Analogs of Atomic Radiative Decay Processes  

E-Print Network [OSTI]

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 ...

Fontana, Peter R.; Srivastava, Rajendra P.

1977-03-01T23:59:59.000Z

452

Quantum Structures of the Hydrogen Atom  

E-Print Network [OSTI]

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?

J. Jeknic-Dugic; M. Dugic; A. Francom; M. Arsenijevic

2014-05-28T23:59:59.000Z

453

Controlling the Ratchet Effect for Cold Atoms  

E-Print Network [OSTI]

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.

Anatole Kenfack; Jiangbin Gong; Arjendu K. Pattanayak

2007-11-27T23:59:59.000Z

454

Atomic resolution images of graphite in air  

SciTech Connect (OSTI)

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.

Grigg, D.A.; Shedd, G.M.; Griffis, D.; Russell, P.E.

1988-12-01T23:59:59.000Z

455

Kinetics of atoms in a bichromatic field  

SciTech Connect (OSTI)

The kinetics of atoms in a bichromatic field is considered. Analytic solutions are obtained for the force, friction coefficient, and diffusion coefficient in the model of a two-level atom without limitations imposed on the intensity of light fields. This effect is observed in the domain of global minima and maxima of the optical potential (i.e., at points where the relative phase of two standing waves is Greek-Phi-Symbol = 0, {pi}/2.

Prudnikov, O. N., E-mail: llf@laser.nsc.ru [Novosibirsk State University (Russian Federation); Baklanov, A. S. [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation); Taichenachev, A. V. [Novosibirsk State University (Russian Federation)] [Novosibirsk State University (Russian Federation); Tumaikin, A. M. [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation)] [Russian Academy of Sciences, Institute of Laser Physics, Siberian Branch (Russian Federation); Yudin, V. I. [Novosibirsk State University (Russian Federation)] [Novosibirsk State University (Russian Federation)

2013-08-15T23:59:59.000Z

456

Studies of atomic hydrogen beam sources  

E-Print Network [OSTI]

Discharge tube & cavity connection to vacuum system. . 10 4 Discharge source system 12 5 Preliminary detection vacuum system 14 6 Penning trap system 16 7 Spectra taken with the bulb discharge tube on the Penning ion trap sys- tem . . 22 6 Spectra... magnetic field with cylin- drical symmetry of order 2n (n = 2, 3, 4, . . . ) results in spin and velocity dependent focussing of the atomic beam. A small permanent hexapole magnet used to focus one spin state of atomic hydrogen while defocussing...

Schafer, Todd William

1989-01-01T23:59:59.000Z

457

Production of mesoscopic superpositions with ultracold atoms  

E-Print Network [OSTI]

We study mesoscopic superpositions of two component Bose-Einstein condensates. Atomic condensates, with long coherence times, are good systems in which to study such quantum phenomenon. We show that the mesoscopic superposition states can be rapidly generated in which the atoms dispersively interact with the photon field in a cavity. We also discuss the production of compass states which are generalized Schr\\"{o}dinger cat states. The physical realization of mesoscopic states is important in studying decoherence and precision measurement.

H. T. Ng

2007-07-16T23:59:59.000Z

458

Hydrogen atom in rotationally invariant noncommutative space  

E-Print Network [OSTI]

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.

Kh. P. Gnatenko; V. M. Tkachuk

2014-11-03T23:59:59.000Z

459

Excess optical quantum noise in atomic sensors  

E-Print Network [OSTI]

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.

Irina Novikova; Eugeniy E. Mikhailov; Yanhong Xiao

2014-10-14T23:59:59.000Z

460

Cavity cooling of an atomic array  

E-Print Network [OSTI]

While cavity cooling of a single trapped emitter was demonstrated, cooling of many particles in an array of harmonic traps needs investigation and poses a question of scalability. This work investigates the cooling of a one dimensional atomic array to the ground state of motion via the interaction with the single mode field of a high-finesse cavity. The key factor ensuring the cooling is found to be the mechanical inhomogeneity of the traps. Furthermore it is shown that the pumped cavity mode does not only mediate the cooling but also provides the necessary inhomogeneity if its periodicity differs from the one of the array. This configuration results in the ground state cooling of several tens of atoms within a few milliseconds, a timescale compatible with current experimental conditions. Moreover, the cooling rate scaling with the atom number reveals a drastic change of the dynamics with the size of the array: atoms are either cooled independently, or via collective modes. In the latter case the cavity mediated atom interaction destructively slows down the cooling as well as increases the mean occupation number, quadratically with the atom number. Finally, an order of magnitude speed up of the cooling is predicted as an outcome the optimization scheme based on the adjustment of the array versus the cavity mode periodicity.

Oxana Mishina

2014-04-16T23:59:59.000Z

Note: This page contains sample records for the topic "atomic shield 1947-1952" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

From Lattice Gauge Theories to Hydrogen Atoms  

E-Print Network [OSTI]

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.

Manu Mathur; T. P. Sreeraj

2014-10-13T23:59:59.000Z

462

Removal site evaluation report on the Tower Shielding Facility at Oak Ridge National Laboratory, Oak Ridge, Tennessee  

SciTech Connect (OSTI)

This removal site evaluation report for the Tower Shielding Facility (TSF) at Oak Ridge National Laboratory was prepared to provide the Environmental Restoration Program with information necessary to evaluate whether hazardous and/or radiological contaminants in and around the Tower Shielding Facility pose a substantial risk to human health or the environment (i.e., a high probability of adverse effects) and if remedial site evaluations or removal actions are, therefore, required. The scope of the project included a review of historical evidence regarding operations and use of the facility; interviews with facility personnel concerning current and past operating practices; a site inspection; and identification of hazard areas requiring maintenance, removal, or remedial actions. Based an the findings of this removal site evaluation, adequate efforts are currently being made at the TSF to contain and control existing contamination and hazardous substances on site in order to protect human health and the environment No conditions requiring maintenance or removal actions to mitigate imminent or potential threats to human health and the environment were identified during this evaluation. Given the current conditions and status of the buildings associated with the TSF, this removal site evaluation is considered complete and terminated according to the requirements for removal site evaluation termination.

NONE

1996-09-01T23:59:59.000Z

463

Atoms for peace and war, 1953-1961: Eisenhower and the Atomic Energy Commission  

SciTech Connect (OSTI)

This third volume in the official history of the U.S. Atomic Energy Commission covers the years of the Eisenhower Administration.

Hewlett, Richard G.; Holl, Jack M.

1989-12-01T23:59:59.000Z

464

Study on reduction in electric field, charged voltage, ion current and ion density under HVDC transmission lines by parallel shield wires  

SciTech Connect (OSTI)

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.

Amano, Y.; Sunaga, Y.

1989-04-01T23:59:59.000Z

465

5 1 Danish Atomic Energy Commission 3 Research Establishment Ris  

E-Print Network [OSTI]

Sponsored by The Danish Atomic Energy Commission and International Atomic Energy Agency Editor V. MejdahlSK S I§ 5 1 Danish Atomic Energy Commission 3 § Research Establishment Risø Risø Report No. 249 P u at the Danish AEC Research Establishment Risø 11-14 October 1971 Sponsored by The Danish Atomic Energy Commit

466

Atoms, Molecules, Moles and Their Masses M. Kostic  

E-Print Network [OSTI]

Atoms, Molecules, Moles and Their Masses M. Kostic One Mole (or abbreviated particles (atoms for elements or molecules for compounds or atomic group, etc.), equal to the number of atoms in 12 grams of C12 carbon. Therefore, 1 mol (or mole) of any substance has the same number, i

Kostic, Milivoje M.

467

Parent--daughter system: D Number of daughter atoms, today  

E-Print Network [OSTI]

- t ) + # , - #12;) . Parent--daughter system: D = N0 ­N D ­ Number of daughter atoms, today N ­ Number of parent atoms, today N0 ­ Number of parent atoms, initially present N0 = D + N, hence: D + N = Net , or D = N et as atoms are transferred from the liquid melt to the solid crystal. Some of the elements incorporated

Siebel, Wolfgang

468

Towards new states of matter with atoms and photons  

E-Print Network [OSTI]

Towards new states of matter with atoms and photons Jonas Larson Stockholm University and Universität zu Köln Aarhus "Cold atoms and beyond" 26/6-2014 #12;Motivation Optical lattices + control QED = coupling between few material (atomic) and few electromagnetic degrees of freedom. Cavity atom

469

PC-ATOMIC Final Report 1 Joseph D. Touch1  

E-Print Network [OSTI]

. This document describes the PC-ATOMIC interface, its design, capabilities, and performance. The board design@isi.edu ABSTRACT: PC-ATOMIC is a PC interface for the ATOMIC LAN. PC- ATOMIC is implemented as a VL-Bus (VESA) short-form card for Intel i486 PCs, providing an interface for low-cost workstations to a 640 Mbps LAN

Touch, Joe

470

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

471

Toward improved photon-atom scattering predictions  

SciTech Connect (OSTI)

Photon-atom scattering is important in a variety of applications, but scattering from a composite system depends on the accurate characterization of the scattering from an isolated atom or ion. We have been examining the validity of simpler approximations of elastic scattering in the light of second-order S-matrix theory. Partitioning the many-body amplitude into Rayleigh and Delbrueck components, processes beyond photoionization contribute. Subtracted cross sections for bound-bound atomic transitions, bound pair annihilation, and bound pair production are required in anomalous scattering factors for: (1) convergence of the dispersion integral; (2) agreement with predictions of the more sophisticated S-matrix approach; (3) satisfying the Thomas-Reiche-Kuhn sum rule. New accurate tabulations of anomalous scattering factors have been prepared for all Z, for energies 0--10,000 keV, within the independent particle approximation (IPA) using a Dirac-Slater model of the atom. Separately, experimental atomic photoabsorption threshold information has been used to modify these IPA predictions for improved comparison with experiment.

Kissel, L.

1994-10-21T23:59:59.000Z

472

Method and apparatus for atomic imaging  

DOE Patents [OSTI]

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.

Saldin, Dilano K. (Milwaukee, WI); de Andres Rodriquez, Pedro L. (Madrid, ES)

1993-01-01T23:59:59.000Z

473

Hydrogen atom in de Sitter spaces  

E-Print Network [OSTI]

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.

O. V. Veko; K. V. Kazmerchuk; E. M. Ovsiyuk; V. M. Red'kov; A. M. Ishkhanyan

2014-12-28T23:59:59.000Z

474

Isolating and moving single atoms using silicon nanocrystals  

DOE Patents [OSTI]

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.

Carroll, Malcolm S. (Albuquerque, NM)

2010-09-07T23:59:59.000Z

475

Atomic-level imaging, processing and characterization of semiconductor surfaces  

DOE Patents [OSTI]

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.

Kazmerski, L.L.

1995-08-22T23:59:59.000Z

476

Atomic-level imaging, processing and characterization of semiconductor surfaces  

DOE Patents [OSTI]

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.

Kazmerski, Lawrence L. (Lakewood, CO)

1995-01-01T23:59:59.000Z

477

Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint  

SciTech Connect (OSTI)

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.

Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

2011-07-01T23:59:59.000Z

478

Optical pumping of a lithium atomic beam for atom interferometry J. Gillot, A. Gauguet, M. Buchner, and J. Vigue  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

479

Standard Model tests with trapped radioactive atoms  

E-Print Network [OSTI]

We review the use of laser cooling and trapping for Standard Model tests, focusing on trapping of radioactive isotopes. Experiments with neutral atoms trapped with modern laser cooling techniques are testing several basic predictions of electroweak unification. For nuclear $\\beta$ decay, demonstrated trap techniques include neutrino momentum measurements from beta-recoil coincidences, along with methods to produce highly polarized samples. These techniques have set the best general constraints on non-Standard Model scalar interactions in the first generation of particles. They also have the promise to test whether parity symmetry is maximally violated, to search for tensor interactions, and to search for new sources of time reversal violation. There are also possibilites for exotic particle searches. Measurements of the strength of the weak neutral current can be assisted by precision atomic experiments using traps of small numbers of radioactive atoms, and sensitivity to possible time-reversal violating electric dipole moments can be improved.

J. A. Behr; G. Gwinner

2009-03-04T23:59:59.000Z

480

Observables in Neutrino Mass Spectroscopy Using Atoms  

E-Print Network [OSTI]

The process of collective de-excitation of atoms in a metastable level into emission mode of a single photon plus a neutrino pair, called radiative emission of neutrino pair (RENP), is sensitive to the absolute neutrino mass scale, to the neutrino mass hierarchy and to the nature (Dirac or Majorana) of massive neutrinos. We investigate how the indicated neutrino mass and mixing observables can be determined from the measurement of the corresponding continuous photon spectrum taking the example of a transition between specific levels of the Yb atom. The possibility of determining the nature of massive neutrinos and, if neutrinos are Majorana fermions, of obtaining information about the Majorana phases in the neutrino mixing matrix, is analyzed in the cases of normal hierarchical, inverted hierarchical and quasi-degenerate types of neutrino mass spectrum. We find, in particular, that the sensitivity to the nature of massive neutrinos depends critically on the atomic level energy difference relevant in the RENP.

D. N. Dinh; S. T. Petcov; N. Sasao; M. Tanaka; M. Yoshimura

2012-09-21T23:59:59.000Z

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481

New charge radius relations for atomic nuclei  

E-Print Network [OSTI]

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.

B. H. Sun; Y. Lu; J. P. Peng; C. Y. Liu; Y. M. Zhao

2014-11-24T23:59:59.000Z

482

Conservation laws and laser cooling of atoms  

E-Print Network [OSTI]

The straightforward application of energy and linear momentum conservation to the absorption/emission of photons by atoms--first outlined by Schr\\"odinger in 1922--allows to establish the essential features of laser cooling of two levels atoms at low laser intensities. The minimum attainable average kinetic energy of the atoms depends on the ratio $\\Gamma/E_R$ between the natural linewidth and the recoil energy and tends to $E_R$ as $\\Gamma/E_R$ tends to zero. This treatment is valid for any value of the ratio $\\Gamma/E_R$ and contains the semiclassical theory of laser cooling as the limiting case in which $E_R\\ll \\Gamma$.

Giuliani, Giuseppe

2015-01-01T23:59:59.000Z

483

Atom Interferometers and the Gravitational Redshift  

E-Print Network [OSTI]

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".

Supurna Sinha; Joseph Samuel

2011-05-16T23:59:59.000Z

484

Atomic multipole relaxation rates near surfaces  

E-Print Network [OSTI]

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.

J. A. Crosse; Stefan Scheel

2010-08-13T23:59:59.000Z

485

Atom trap trace analysis of krypton isotopes  

SciTech Connect (OSTI)

A new method of ultrasensitive isotope trace analysis has been developed. This method, based on the technique of laser manipulation of neutral atoms, has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton gas sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. This method is free of contamination from other isotopes and elements and can be applied to several different isotope tracers for a wide range of applications. The demonstrated detection efficiency is 1 x 10{sup {minus}7}. System improvements could increase the efficiency by many orders of magnitude.

Bailey, K.; Chen, C. Y.; Du, X.; Li, Y. M.; Lu, Z.-T.; O'Connor, T. P.; Young, L.

1999-11-17T23:59:59.000Z

486

Probing Dark Energy with Atom Interferometry  

E-Print Network [OSTI]

Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

Clare Burrage; Edmund J. Copeland; E. A. Hinds

2014-08-06T23:59:59.000Z