Sample records for rf respirable fraction

  1. Determination of respirable mass concentration using a high volume air sampler and a sedimentation method for fractionation

    SciTech Connect (OSTI)

    Johnson, J.

    1995-12-31T23:59:59.000Z

    A preliminary study of a new method for determining respirable mass concentration is described. This method uses a high volume air sampler and subsequent fractionation of the collected mass using a particle sedimentation technique. Side-by-side comparisons of this method with cyclones were made in the field and in the laboratory. There was good agreement among the samplers in the laboratory, but poor agreement in the field. The effect of wind on the samplers` capture efficiencies is the primary hypothesized source of error among the field results. The field test took place at the construction site of a hazardous waste landfill located on the Hanford Reservation.

  2. ENHANCING NETWORK SECURITY USING 'LEARNING-FROM-SIGNALS' AND FRACTIONAL FOURIER TRANSFORM BASED RF-DNA FINGERPRINTS

    SciTech Connect (OSTI)

    Buckner, Mark A [ORNL; Bobrek, Miljko [ORNL; Farquhar, Ethan [ORNL; Harmer, Paul K [Air Force Institute of Technology; Temple, Michael A [Air Force Institute of Technology

    2011-01-01T23:59:59.000Z

    Wireless Access Points (WAP) remain one of the top 10 network security threats. This research is part of an effort to develop a physical (PHY) layer aware Radio Frequency (RF) air monitoring system with multi-factor authentication to provide a first-line of defense for network security--stopping attackers before they can gain access to critical infrastructure networks through vulnerable WAPs. This paper presents early results on the identification of OFDM-based 802.11a WiFi devices using RF Distinct Native Attribute (RF-DNA) fingerprints produced by the Fractional Fourier Transform (FRFT). These fingerprints are input to a "Learning from Signals" (LFS) classifier which uses hybrid Differential Evolution/Conjugate Gradient (DECG) optimization to determine the optimal features for a low-rank model to be used for future predictions. Results are presented for devices under the most challenging conditions of intra-manufacturer classification, i.e., same-manufacturer, same-model, differing only in serial number. The results of Fractional Fourier Domain (FRFD) RF-DNA fingerprints demonstrate significant improvement over results based on Time Domain (TD), Spectral Domain (SD) and even Wavelet Domain (WD) fingerprints.

  3. University of Rochester Respirator Training

    E-Print Network [OSTI]

    Mahon, Bradford Z.

    (SCBA) UofR Respirator Training 8 #12;Air Purifying Respirators (Particulate) Tight-fitting respirator

  4. Fabrication of microfluidic devices for artificial respiration

    E-Print Network [OSTI]

    Park, Hyesung, Ph. D. Massachusetts Institute of Technology

    2007-01-01T23:59:59.000Z

    We are developing elastomeric polydimethylsiloxane (PDMS) microfluidic devices incorporated with photoactive thin films to create an implantable artificial respiration platform. Whereas state-of-the-art respiration support ...

  5. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    SciTech Connect (OSTI)

    S.O. Bader

    1999-10-18T23:59:59.000Z

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be conservatively applied to confined CSNF assemblies.

  6. Superconducting RF Cryomodule Demagnetization

    E-Print Network [OSTI]

    Crawford, Anthony C

    2015-01-01T23:59:59.000Z

    This note presents measurements that support the proposition that it is feasible to demagnetize a fully assembled superconducting RF cryomodule.

  7. June 2011 Page 1 of 3 Respirator Request Form

    E-Print Network [OSTI]

    Wilcock, William

    INDUSTRIAL HYGIENE ASSESSMENT 18. Respirator(s) Selected Half-Face cartridge Full-Face cartridge PAPR SCBA

  8. Rf Feedback free electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

  9. Commercial SNF Accident Release Fractions

    SciTech Connect (OSTI)

    J. Schulz

    2004-11-05T23:59:59.000Z

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the container that confines the fuel assemblies could provide an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. This analysis, however, does not take credit for the additional barrier and establishes only the total release fractions for bare unconfined intact commercial SNF assemblies, which may be conservatively applied to confined intact commercial I SNF assemblies.

  10. Phase stable RF transport system

    DOE Patents [OSTI]

    Curtin, Michael T. (Los Alamos, NM); Natter, Eckard F. (San Francisco, CA); Denney, Peter M. (Los Alamos, NM)

    1992-01-01T23:59:59.000Z

    An RF transport system delivers a phase-stable RF signal to a load, such as an RF cavity of a charged particle accelerator. A circuit generates a calibration signal at an odd multiple frequency of the RF signal where the calibration signal is superimposed with the RF signal on a common cable that connects the RF signal with the load. Signal isolating diplexers are located at both the RF signal source end and load end of the common cable to enable the calibration to be inserted and extracted from the cable signals without any affect on the RF signal. Any phase shift in the calibration signal during traverse of the common cable is then functionally related to the phase shift in the RF signal. The calibration phase shift is used to control a phase shifter for the RF signal to maintain a stable RF signal at the load.

  11. anaerobic respiring bacteria: Topics by E-print Network

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

    of locomotion, feeding and respiration (Weiss, 1950; von Holst, 1973; Hildebrand, 1980 Wainwright, Peter C. 55 Automated soil respiration measurements: new information,...

  12. Advances in Photosynthesis and Respiration Series Editor

    E-Print Network [OSTI]

    Govindjee "Gov"

    Springer Advances in Photosynthesis and Respiration Series Editor: Govindjee, University of Illinois at Urbana-Champaign, USA Volume 29 Photosynthesis in silico Understanding Complexity from Molecules to Ecosystems Edited by; A. Laisk, L. Nedbal, and Govindjee Photosynthesis in silico

  13. Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume 1

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T, Inc.'s Reply Comments AT&T,FACT S HEET FACTAgenda: TheAof(2010-SE-0301) TS

  14. Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume II

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T, Inc.'s Reply Comments AT&T,FACT S HEET FACTAgenda: TheAof(2010-SE-0301) TS

  15. RF test bench automation Description

    E-Print Network [OSTI]

    Dobigeon, Nicolas

    RF test bench automation Description: Callisto would like to implement automated RF test bench. Three RF test benches have to be studied and automated: LNA noise temperature test bench LNA gain phase of the test benches and an implementation of the automation phase. Tasks: Noise temperature

  16. Development of conformal respirator monitoring technology

    SciTech Connect (OSTI)

    Shonka, J.J.; Weismann, J.J.; Logan, R.J. [and others

    1997-04-01T23:59:59.000Z

    This report summarizes the results of a Small Business Innovative Research Phase II project to develop a modular, surface conforming respirator monitor to improve upon the manual survey techniques presently used by the nuclear industry. Research was performed with plastic scintillator and gas proportional modules in an effort to find the most conducive geometry for a surface conformal, position sensitive monitor. The respirator monitor prototype developed is a computer controlled, position-sensitive detection system employing 56 modular proportional counters mounted in molds conforming to the inner and outer surfaces of a commonly used respirator (Scott Model 801450-40). The molds are housed in separate enclosures and hinged to create a {open_quotes}waffle-iron{close_quotes} effect so that the closed monitor will simultaneously survey both surfaces of the respirator. The proportional counter prototype was also designed to incorporate Shonka Research Associates previously developed charge-division electronics. This research provided valuable experience into pixellated position sensitive detection systems. The technology developed can be adapted to other monitoring applications where there is a need for deployment of many traditional radiation detectors.

  17. Announcement Advances in Photosynthesis and Respiration: Focus on Plant

    E-Print Network [OSTI]

    Govindjee "Gov"

    Announcement Advances in Photosynthesis and Respiration: Focus on Plant Respiration I am delighted to announce the publication, in the Advances in Photosynthesis and Respiration (AIPH) series, of two books, Michael T. Madigan and Carl E. Bauer, editors, 1995); 3. Biophysical Techniques in Photosynthesis (Jan

  18. Ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Ji, Qing; Wilde, Stephen

    2005-12-13T23:59:59.000Z

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source.

  19. RF power generation

    E-Print Network [OSTI]

    Carter, R G

    2011-01-01T23:59:59.000Z

    This paper reviews the main types of r.f. power amplifiers which are, or may be, used for particle accelerators. It covers solid-state devices, tetrodes, inductive output tubes, klystrons, magnetrons, and gyrotrons with power outputs greater than 10 kW c.w. or 100 kW pulsed at frequencies from 50 MHz to 30 GHz. Factors affecting the satisfactory operation of amplifiers include cooling, matching and protection circuits are discussed. The paper concludes with a summary of the state of the art for the different technologies.

  20. The MUCOOL RF Program

    SciTech Connect (OSTI)

    Norem, J.; /Argonne; Bross, A.; Moretti, A.; Norris, B.; Qian, Z.; /Fermilab; Torun, Y.; /IIT, Chicago; Rimmer, R.; /Jefferson Lab; Li, D.; Virostek, S.; Zisman, M.; /LBL,; Sandstrom, R.; /Geneva U.

    2006-06-26T23:59:59.000Z

    Efficient muon cooling requires high RF gradients in the presence of high (3T) solenoidal fields. The Muon Ionization Cooling Experiment (MICE) also requires that the x-ray production from these cavities is low, in order to minimize backgrounds in the particle detectors that must be located near the cavities. These cavities require thin Be windows to ensure the highest fields on the beam axis. In order to develop these cavities, the MUCOOL RF Program was started about 6 years ago. Initial measurements were made on a six-cell cavity and a single-cell pillbox, both operating at 805 MHz. We have now begun measurements of a 201 MHz pillbox cavity. This program has led to new techniques to look at dark currents, a new model for breakdown and a general model of cavity performance based on surface damage. The experimental program includes studies of thin Be windows, conditioning, dark current production from different materials, magnetic-field effects and breakdown.

  1. Diffusion in biofilms respiring on electrodes

    SciTech Connect (OSTI)

    Renslow, Ryan S.; Babauta, Jerome T.; Majors, Paul D.; Beyenal, Haluk

    2013-02-15T23:59:59.000Z

    The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (De) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed for noninvasive, nondestructive, high spatial resolution in situ De measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensional De heat maps and surface-averaged relative effective diffusion coefficient (Drs) depth profiles. We found that (1) Drs decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; (2) Drs at a given location decreases with G. sulfurreducens biofilm age; (3) average De and Drs profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms—the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and (4) halting the respiration of a G. sulfurreducens biofilm decreases the De values. Density, reflected by De, plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms.

  2. Unbalanced field RF electron gun

    DOE Patents [OSTI]

    Hofler, Alicia

    2013-11-12T23:59:59.000Z

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  3. Modeling nighttime ecosystem respiration from measured CO2 concentration and air temperature profiles using inverse methods

    E-Print Network [OSTI]

    Modeling nighttime ecosystem respiration from measured CO2 concentration and air temperature ecosystem carbon budgets from micrometeorological methods remains nighttime ecosystem respiration theory to infer the two components of ecosystem respiration (aboveground and forest floor) from measured

  4. A nonparametric method for separating photosynthesis and respiration components in CO2 flux measurements

    E-Print Network [OSTI]

    A nonparametric method for separating photosynthesis and respiration components in CO2 flux dependence of photosynthesis and respiration. This observation provides empirical validation of efforts consideration of the temperature dependence of respiration and photosynthesis are likely to carry significant

  5. Announcement Advances in Photosynthesis and Respiration, Volume 24

    E-Print Network [OSTI]

    Govindjee "Gov"

    Announcement Advances in Photosynthesis and Respiration, Volume 24 (Photosystem I) I am delighted to announce, in Advances in Photosynthesis and Respiration (AIPH) Series, the publication of Volume 24; ISBN: 0-7923-3682-8); · Volume 3: Biophysical Techniques in Photosynthesis (24 chapters; 411 pages

  6. Announcement Advances in Photosynthesis and Respiration, Volume 19: `Chlorophyll a

    E-Print Network [OSTI]

    Govindjee "Gov"

    Announcement Advances in Photosynthesis and Respiration, Volume 19: `Chlorophyll a Fluorescence: A Signature of Photosynthesis', edited by George C. Papageorgiou and Govindjee I am delighted to announce the publication, in the Advances in Photosynthesis and Respiration (AIPH) series, of the first book that focuses

  7. Coupling of Photosynthesis and Respiration Phloem Transport is

    E-Print Network [OSTI]

    Simon, Emmanuel

    Coupling of Photosynthesis and Respiration ­ Phloem Transport is still a Mystery Arthur Gessler1 sources and sinks VanBel(2003) sugars water growth temperature nutrients photosynthesis light CO2 water #12;The coupling between photosynthesis and respiration 13C plant biomass and phloem 13C

  8. Strengthening Line Management Oversight and Federal Monitoring...

    Office of Environmental Management (EM)

    Safety Analysis iv PHA Preliminary Hazards Analysis PSDR Preliminary Safety Design Report PSVR Preliminary Safety Validation Report QA Quality Assurance RF Respirable Fraction...

  9. Phase modulation in RF tag

    DOE Patents [OSTI]

    Carrender, Curtis Lee; Gilbert, Ronald W.

    2007-02-20T23:59:59.000Z

    A radio frequency (RF) communication system employs phase-modulated backscatter signals for RF communication from an RF tag to an interrogator. The interrogator transmits a continuous wave interrogation signal to the RF tag, which based on an information code stored in a memory, phase-modulates the interrogation signal to produce a backscatter response signal that is transmitted back to the interrogator. A phase modulator structure in the RF tag may include a switch coupled between an antenna and a quarter-wavelength stub; and a driver coupled between the memory and a control terminal of the switch. The driver is structured to produce a modulating signal corresponding to the information code, the modulating signal alternately opening and closing the switch to respectively decrease and increase the transmission path taken by the interrogation signal and thereby modulate the phase of the response signal. Alternatively, the phase modulator may include a diode coupled between the antenna and driver. The modulating signal from the driver modulates the capacitance of the diode, which modulates the phase of the response signal reflected by the diode and antenna.

  10. Muon spin rotation studies of niobium for superconducting RF applications

    E-Print Network [OSTI]

    Grassellino, A; Kolb, P; Laxdal, R; Lockyer, N S; Longuevergne, D; Sonier, J E

    2013-01-01T23:59:59.000Z

    In this work we investigate superconducting properties of niobium samples via application of the muon spin rotation/relaxation (muSR) technique. We employ for the first time the muSR technique to study samples that are cutout from large and small grain 1.5 GHz radio frequency (RF) single cell niobium cavities. The RF test of these cavities was accompanied by full temperature mapping to characterize the RF losses in each of the samples. Results of the muSR measurements show that standard cavity surface treatments like mild baking and buffered chemical polishing (BCP) performed on the studied samples affect their surface pinning strength. We find an interesting correlation between high field RF losses and field dependence of the sample magnetic volume fraction measured via muSR. The muSR line width observed in ZF-muSR measurements matches the behavior of Nb samples doped with minute amounts of Ta or N impurities. An upper bound for the upper critical field Hc2 of these cutouts is found.

  11. Cryogenic vacuumm RF feedthrough device

    DOE Patents [OSTI]

    Wu, Genfa (Yorktown, VA); Phillips, Harry Lawrence (Hayes, VA)

    2008-12-30T23:59:59.000Z

    A cryogenic vacuum rf feedthrough device comprising: 1) a probe for insertion into a particle beam; 2) a coaxial cable comprising an inner conductor and an outer conductor, a dielectric/insulating layer surrounding the inner conductor, the latter being connected to the probe for the transmission of higher mode rf energy from the probe; and 3) a high thermal conductivity stub attached to the coaxial dielectric about and in thermal contact with the inner conductor which high thermal conductivity stub transmits heat generated in the vicinity of the probe efficiently and radially from the area of the probe and inner conductor all while maintaining useful rf transmission line characteristics between the inner and outer coaxial conductors.

  12. Negative ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13T23:59:59.000Z

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  13. advanced rf gun: Topics by E-print Network

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

    attached to the RF gun is shown in Fig. 1. The RF gun is an L-band 1 12- cell RF gun 4 TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities Physics...

  14. Molecular Characterization of Bacterial Respiration on Minerals

    SciTech Connect (OSTI)

    Blake, Robert C.

    2013-04-26T23:59:59.000Z

    The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully analyze a natural community using these techniques; 3. Detailed functional and structural studies were conducted on rusticyanin, an acid-stable electron transfer protein purified from cell-free extracts of At. ferrooxidans. The three-dimensional structure of reduced rusticyanin was determined from a combination of homonuclear proton and heteronuclear 15N- and 13C-edited NMR spectra. Concomitantly, the three-dimensional structure of oxidized rusticyanin was determined by X-ray crystallography to a resolution of 1.9 A by multiwavelength anomalous dispersion (MAD) phasing; 4. An acid-stable red cytochrome with a novel absorbance peak at 579 nm was purified from cell-free extracts of L. ferriphilum. Functional studies demonstrated that this cytochrome was an important component of the aerobic iron respiratory chain in this organism; 5. The specific adhesion of At. ferrooxidans to pyrite is mediated by an extracellular protein that was identified as aporusticyanin. The adhesion of At. ferrooxidans to minerals was characterized by high affinity binding that exhibited a high specificity for pyrite over other sulfide minerals. The principal biopolymer involved in this high-affinity adhesion to pyrite was isolated by mineral affinity chromatography and identified as aporusticyanin. The adhesion of purified aporusticyanin to minerals was observed to adhere to different mineral with a pattern of reactivity identical to that observed with the intact bacterium. Further, preincubation of pyrite with excess exogenous aporusticyanin served to inhibit the adherence of intact cells to the surface of the mineral, indicating that the protein and the cells adhered to the pyrite in a mutually exclusive manner. Taken together, these observations support a model where aporusticyanin located on the surface of the bacterial cell acts as a mineral-specific receptor for the initial adherence of At. ferrooxidans to solid pyrite; 6. The specific adhesion of L. ferriphilum to pyrite was mediated by a different acid-stable extracellular protein than aporusticyanin; and 7. A prototype integrating cavity absorption meter (ICAM) was assembled to determine whether this novel spectrophotometer could be used to study cellular respiration in situ.

  15. High-Power Rf Load

    DOE Patents [OSTI]

    Tantawi, Sami G. (San Mateo, CA); Vlieks, Arnold E. (Livermore, CA)

    1998-09-01T23:59:59.000Z

    A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

  16. Thermal adaptation of soil microbial respiration to elevated temperature

    E-Print Network [OSTI]

    Mohan, Jacqueline E.

    LETTER Thermal adaptation of soil microbial respiration to elevated temperature Mark A. Bradford,1 within a few years (Jarvis & Linder 2000; Oechel et al. 2000; Luo et al. 2001; Rustad et al. 2001

  17. The effect of temperature and humidity on respirator fit 

    E-Print Network [OSTI]

    Niekerk, Gary

    1986-01-01T23:59:59.000Z

    THE EFFECT OF TEMPERATURE AND HUMIDITY ON RESPIRATOR FIT A Thesis by GARY NIEKERK Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1986 Maj... or Subject: Industr ial Hygiene THE EFFECT OF TEMPERATURE AND HUMIDITY ON RESPIRATOR FIT A Thesis by Gary Niekerk Approved as to style and content by: c . o n ( Chairman of Coami ttee) a . e non (Member) anie . ones (Member) e an . an (Head...

  18. DOE-HDBK-3010-94; Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume II

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

    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 DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No Significant Impact6

  19. DOE-HDBK-3010-94; Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA Approved:AdministrationAnalysisDarby/%2AO 474.2 Chg U.S. S p e chonors

  20. Low jitter RF distribution system

    DOE Patents [OSTI]

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18T23:59:59.000Z

    A timing signal distribution system includes an optical frequency stabilized laser signal amplitude modulated at an rf frequency. A transmitter box transmits a first portion of the laser signal and receive a modified optical signal, and outputs a second portion of the laser signal and a portion of the modified optical signal. A first optical fiber carries the first laser signal portion and the modified optical signal, and a second optical fiber carries the second portion of the laser signal and the returned modified optical signal. A receiver box receives the first laser signal portion, shifts the frequency of the first laser signal portion outputs the modified optical signal, and outputs an electrical signal on the basis of the laser signal. A detector at the end of the second optical fiber outputs a signal based on the modified optical signal. An optical delay sensing circuit outputs a data signal based on the detected modified optical signal. An rf phase detect and correct signal circuit outputs a signal corresponding to a phase stabilized rf signal based on the data signal and the frequency received from the receiver box.

  1. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

    Brau, C.A.; Stein, W.E.; Rockwood, S.D.

    1981-02-11T23:59:59.000Z

    A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.

  2. A 113 L/min ambient aerosol sampler for collection of thoracic and respirable fractions 

    E-Print Network [OSTI]

    Rue, Clayton Matthew

    1981-01-01T23:59:59.000Z

    INTRODUCTION REVIEW OF PREVIOUS NORK METHODOLOGY Introduction Flow Splitter Tests w1th Oleic Acid Particles Tests with Polystyrene Particles Cyclone Mod1ficat1on RESULTS Data Analysis Discussion of Errors SUMMARY AND CONCLUSIONS Pa&ac 15 19 19... 60 26 E oa100 o 80 c? ?I ~ 60 E ~ 40 20 I ? I '? 1? ? 0. 01 0. 1 1 10 100 Particle diameter (Dp) &? m Figure 3. Examples of atmospheric aerosol distributions which show bi-modal patterns, Lundgren and Paulus (1975). uranium...

  3. A 113 L/min ambient aerosol sampler for collection of thoracic and respirable fractions

    E-Print Network [OSTI]

    Rue, Clayton Matthew

    1981-01-01T23:59:59.000Z

    of the particulate matter collected by the TTP filter, Figure 4. This flow splitter is an 1ntegral part of the 10. 2 cm (4. 0 in. ) s'upport: for the 10 um sampl1ng inlet. Half of the aerosol flow containing the TTP particles passes through the center... for the 2. 38 um size, Table B-3. Experi- ments with these two aerosols were evaluated with the opt1cal counter. All other tests were conducted with the fluorescein-tagged ole1c acid aerosols. The 2. 37 um ole1c ac1d aerosols were chosen to concide...

  4. RF Systems in a Neutrino Factory

    SciTech Connect (OSTI)

    Berg J. S.

    2012-09-07T23:59:59.000Z

    Based on existing sources, I compile parameters for the RF systems for a neutrino factory which accelerates to 10 GeV.

  5. RF/optical shared aperture for high availability wideband communication RF/FSO links

    DOE Patents [OSTI]

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2014-04-29T23:59:59.000Z

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  6. Predictions of microwavePredictions of microwave breakdown in rf structuresbreakdown in rf structures

    E-Print Network [OSTI]

    Yu, Ming

    Predictions of microwave breakdownPredictions of microwave breakdown in rf structuresin rf structures #12;2 of the breakdown phenomenon). 2. Electron interaction with microwave field (rough estimates of parameters which in communication systems Predictions of microwave breakdown in rf structuresPredictions of microwave breakdown

  7. Comparing nocturnal eddy covariance measurements to estimates of ecosystem respiration made by scaling chamber measurements at six coniferous boreal sites

    E-Print Network [OSTI]

    1997-01-01T23:59:59.000Z

    construction respiration estimated as 0.25 times wood NPP [construction respiration estimated as 0.25 E times foliage NPP (construction respiration was 1.6-3.6 times greater than 0.25 times wood NPP

  8. RF power recovery feedback circulator

    DOE Patents [OSTI]

    Sharamentov, Sergey I. (Bolingbrook, IL)

    2011-03-29T23:59:59.000Z

    A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.

  9. The effect of temperature and humidity on respirator fit

    E-Print Network [OSTI]

    Niekerk, Gary

    1986-01-01T23:59:59.000Z

    of atmosphere- supplying respirator is the self-contained breathing apparatus (SCBA). These devices are not connected to a stationary air source, such as a compressor. Instead, air is supplied from a compressed air or oxygen tank carried on the person...

  10. Measurement of chlorite dismutase activities in perchlorate respiring bacteria

    E-Print Network [OSTI]

    concentration (0.6 mM) to four other perchlorate respiring bacteria (PRB), and to one non-PRB (Pseudomonas aeruginosa). Chlorate-grown cultures of the five PRB strains had CD activities ranging from 25 to 50 U/mg of cell dry weight (DW), while aerobically grown cultures of the PRB had much lower CD activities (0.5­4 U

  11. ACCLIMATION OF PHOTOSYNTHESIS AND RESPIRATION TO INCREASING TEMPERATURES IN TREES

    E-Print Network [OSTI]

    Teskey, Robert O.

    ACCLIMATION OF PHOTOSYNTHESIS AND RESPIRATION TO INCREASING TEMPERATURES IN TREES by JASON ERIC in mean growing season temperature. This allowed us to determine whether net photosynthesis and dark rates of net photosynthesis were similar among seedlings when compared to their respective mean site

  12. Ecosystem Respiration in a Cool Temperate Bog Depends on Peat

    E-Print Network [OSTI]

    Roulet, Nigel T.

    Ecosystem Respiration in a Cool Temperate Bog Depends on Peat Temperature But Not Water Table P-summer (July-August). As anticipated, there was a strong relationship between ER and peat temperatures (r2 = 0-table depth (r2 = 0.11). A laboratory incubation of peat cores at different moisture contents showed that CO2

  13. Robust Diamond-Based RF Switch Yields Enhanced Communication...

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

    Robust Diamond-Based RF Switch Yields Enhanced Communication Capabilities Technology available for licesning: A radio frequency (RF) microelectromechanical system (MEMS) switch...

  14. Linear Gain for the Microbunching Instability in an RF Compressor

    E-Print Network [OSTI]

    Venturini, M.

    2010-01-01T23:59:59.000Z

    Instability in an RF Compressor M. Venturini Lawrencefor investigating this instability in rf compressors. We useapplied to magnetic compressors [2, 3] and derive some

  15. Microwave (MW) and Radio Frequency (RF) as Enabling Technologies...

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

    Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced...

  16. A study of respiration-correlated cone-beam CT scans to correct target positioning errors in radiotherapy of thoracic cancer

    SciTech Connect (OSTI)

    Santoro, J. P.; McNamara, J.; Yorke, E.; Pham, H.; Rimner, A.; Rosenzweig, K. E.; Mageras, G. S. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States)

    2012-10-15T23:59:59.000Z

    Purpose: There is increasingly widespread usage of cone-beam CT (CBCT) for guiding radiation treatment in advanced-stage lung tumors, but difficulties associated with daily CBCT in conventionally fractionated treatments include imaging dose to the patient, increased workload and longer treatment times. Respiration-correlated cone-beam CT (RC-CBCT) can improve localization accuracy in mobile lung tumors, but further increases the time and workload for conventionally fractionated treatments. This study investigates whether RC-CBCT-guided correction of systematic tumor deviations in standard fractionated lung tumor radiation treatments is more effective than 2D image-based correction of skeletal deviations alone. A second study goal compares respiration-correlated vs respiration-averaged images for determining tumor deviations. Methods: Eleven stage II-IV nonsmall cell lung cancer patients are enrolled in an IRB-approved prospective off-line protocol using RC-CBCT guidance to correct for systematic errors in GTV position. Patients receive a respiration-correlated planning CT (RCCT) at simulation, daily kilovoltage RC-CBCT scans during the first week of treatment and weekly scans thereafter. Four types of correction methods are compared: (1) systematic error in gross tumor volume (GTV) position, (2) systematic error in skeletal anatomy, (3) daily skeletal corrections, and (4) weekly skeletal corrections. The comparison is in terms of weighted average of the residual GTV deviations measured from the RC-CBCT scans and representing the estimated residual deviation over the treatment course. In the second study goal, GTV deviations computed from matching RCCT and RC-CBCT are compared to deviations computed from matching respiration-averaged images consisting of a CBCT reconstructed using all projections and an average-intensity-projection CT computed from the RCCT. Results: Of the eleven patients in the GTV-based systematic correction protocol, two required no correction, seven required a single correction, one required two corrections, and one required three corrections. Mean residual GTV deviation (3D distance) following GTV-based systematic correction (mean {+-} 1 standard deviation 4.8 {+-} 1.5 mm) is significantly lower than for systematic skeletal-based (6.5 {+-} 2.9 mm, p= 0.015), and weekly skeletal-based correction (7.2 {+-} 3.0 mm, p= 0.001), but is not significantly lower than daily skeletal-based correction (5.4 {+-} 2.6 mm, p= 0.34). In two cases, first-day CBCT images reveal tumor changes-one showing tumor growth, the other showing large tumor displacement-that are not readily observed in radiographs. Differences in computed GTV deviations between respiration-correlated and respiration-averaged images are 0.2 {+-} 1.8 mm in the superior-inferior direction and are of similar magnitude in the other directions. Conclusions: An off-line protocol to correct GTV-based systematic error in locally advanced lung tumor cases can be effective at reducing tumor deviations, although the findings need confirmation with larger patient statistics. In some cases, a single cone-beam CT can be useful for assessing tumor changes early in treatment, if more than a few days elapse between simulation and the start of treatment. Tumor deviations measured with respiration-averaged CT and CBCT images are consistent with those measured with respiration-correlated images; the respiration-averaged method is more easily implemented in the clinic.

  17. Sediment Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary

    E-Print Network [OSTI]

    Vallino, Joseph J.

    Sediment Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary Semester and denitrification potentials. We found that the more eutrophic sites had higher respiration and ammonification. Our

  18. Variations of the Respiration Signals for Respiratory-Gated Radiotherapy Using the Video Coached Respiration Guiding System

    E-Print Network [OSTI]

    Lee, Hyun Jeong; Oh, Se An

    2015-01-01T23:59:59.000Z

    Respiratory-gated radiation therapy (RGRT) has been used to minimize the dose to normal tissue in lung-cancer radiotherapy. The present research aims to improve the regularity of respiration in RGRT using a video coached respiration guiding system. In the study, 16 patients with lung cancer were evaluated. The respiration signals of the patients were measured by a real-time position management (RPM) Respiratory Gating System (Varian, USA) and the patients were trained using the video coached respiration guiding system. The patients performed free breathing and guided breathing, and the respiratory cycles were acquired for ~5 min. Then, Microsoft Excel 2010 software was used to calculate the mean and standard deviation for each phase. The standard deviation was computed in order to analyze the improvement in the respiratory regularity with respect to the period and displacement. The standard deviation of the guided breathing decreased to 65.14% in the inhale peak and 71.04% in the exhale peak compared with the...

  19. Simulations of Ion Migration in the LCLS RF Gun and Injector

    SciTech Connect (OSTI)

    Brachmann, Axel; /SLAC; Dowell, David; /SLAC

    2012-06-25T23:59:59.000Z

    The motivation for this work was the observed surface contamination of the first LCLS RF gun copper cathode. We will present the results of simulations in regards to ion migration in the LCLS gun. Ions of residual gases will be created by interaction of molecular gas species with the UV drive laser beam and by the electron beam itself. The larger part of those ionized molecules remain in the vicinity of creation, are transported towards beam line walls or away from the cathode. However a small fraction gains enough kinetic energy, focused by RF and magnetic fields and propagates to the cathode, producing an undesirable increase of the cathode's surface work function. Although this fraction is small, during long term operation, this effect may become a significant factor limiting the source performance.

  20. Some new methods of RF control

    SciTech Connect (OSTI)

    Jachim, S.P.

    1990-01-01T23:59:59.000Z

    This presentation will focus on several recent developments at Los Alamos in the area of RF control for accelerators. Included in the discussion will be in-phase/quadrature (I/Q) field control, the application of six-port reflectometers for cavity instrumentation and resonance control, a technique for phase stabilization of critical RF cables, an application of state-variable feedback for field control, and the direct integration of RF and computer-interface hardware using the VXIbus standard. 25 refs., 8 figs.

  1. Matching network for RF plasma source

    DOE Patents [OSTI]

    Pickard, Daniel S. (Palo Alto, CA); Leung, Ka-Ngo (Hercules, CA)

    2007-11-20T23:59:59.000Z

    A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.

  2. Multi-level RF identification system

    DOE Patents [OSTI]

    Steele, Kerry D.; Anderson, Gordon A.; Gilbert, Ronald W.

    2004-07-20T23:59:59.000Z

    A radio frequency identification system having a radio frequency transceiver for generating a continuous wave RF interrogation signal that impinges upon an RF identification tag. An oscillation circuit in the RF identification tag modulates the interrogation signal with a subcarrier of a predetermined frequency and modulates the frequency-modulated signal back to the transmitting interrogator. The interrogator recovers and analyzes the subcarrier signal and determines its frequency. The interrogator generates an output indicative of the frequency of the subcarrier frequency, thereby identifying the responding RFID tag as one of a "class" of RFID tags configured to respond with a subcarrier signal of a predetermined frequency.

  3. Degreasing and cleaning superconducting RF Niobium cavities

    SciTech Connect (OSTI)

    Rauchmiller, Michael; Kellett, Ron; /Fermilab

    2011-09-01T23:59:59.000Z

    The purpose and scope of this report is to detail the steps necessary for degreasing and cleaning of superconducting RF Niobium cavities in the A0 clean room. It lists the required equipment and the cleaning procedure.

  4. Superconducting RF Injector T. Srinivasan-Rao

    E-Print Network [OSTI]

    current injector Heat LossRF Requirements Superconducting injector Photocathode Cesium Telluride Nb(degrees) Cooled to 4 K. Undercoupled Frequency: ~1301.5727 MHz, Loaded Q:~1x107-Contaminants effect? Freq. Vs

  5. Si-based RF MEMS components.

    SciTech Connect (OSTI)

    Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D.; Dyck, Christopher William

    2005-01-01T23:59:59.000Z

    Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.

  6. Deeply scaled CMOS for RF power applications

    E-Print Network [OSTI]

    Scholvin, Jörg, 1976-

    2006-01-01T23:59:59.000Z

    The microelectronics industry is striving to reduce the cost, complexity, and form factor of wireless systems through single-chip integration of analog, RF and digital functions. Driven by the requirements of the digital ...

  7. Monolithic RF frontends for ubiquitous wireless connectivity

    E-Print Network [OSTI]

    Goswami, Sushmit

    2014-01-01T23:59:59.000Z

    The desire for ubiquitous connectivity is pushing radios towards highly-integrated, multi-standard and multi-band implementations. This thesis explores architectures for next-generation RF frontends, which form the interface ...

  8. Samsung: ENERGY STAR Referral (RF26VAB)

    Broader source: Energy.gov [DOE]

    DOE referred the matter of Samsung refrigerator-freezer model RF26VAB to the EPA for appropriate action after DOE testing showed that the model does not meet the ENERGY STAR specification.

  9. EXPERIMENTAL STUDIES OF RF BREAKDOWNS IN THE COUPLER OF THE TTF RF GUN

    E-Print Network [OSTI]

    to han- dle 800 µs long RF pulses with 4.5 MW of peak power and at 10 Hz repetition rate. In this regime

  10. Fraction Collector User Manual

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    Fraction Collector Frac-950 18-1139-56 User Manual #12;#12;Important user information All users Territories Hong Kong © Copyright Amersham Biosciences AB 2002 - All rights reserved Fraction Collector Frac Fraction Collector Frac-950 User Manual 18-1139-56 Edition AE v Contents 1 Introduction 1.1 General

  11. Conclusions Fractionated Space Systems

    E-Print Network [OSTI]

    de Weck, Olivier L.

    Conclusions Fractionated Space Systems There is a growing interest in fractionated space system design. Fractionated space systems are inherently flexible and modular. There are many key technologies of flexibility serves as a source of motivation for system designers to embed flexibility into a system design (i

  12. Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers

    E-Print Network [OSTI]

    Hassan, Muhammad

    2012-01-01T23:59:59.000Z

    RF power amplifier applications," IEEE Journal of Solid-RF power amplifier applications," IEEE Journal of Solid-RF power amplifier applications," IEEE Journal of Solid-

  13. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    SciTech Connect (OSTI)

    Johnson, Rolland

    2014-09-21T23:59:59.000Z

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A 1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

  14. The energetics of growth, respiration, and egestion of juvenile striped mullet, Mugil cephalus Linnaeus 

    E-Print Network [OSTI]

    Muska, Carl Frank

    1973-01-01T23:59:59.000Z

    not have yielded useful results due to the effect of ration size on the water, protein, and caloric content of the fish. This study demonstrates the desirability of measuring growth in terms of changes in total protein and calories. Partial energy.... . . . . . . RESULTS. Experiment 1 Growth Caloric Analyses. Respiration. Unmeasured Energy Loss. Experiment 2. Growth. Caloric and Protein Analyses. Respiration. Egestion. DISCUSSION. Experiment l. Growth. Respiration Energy Budgets and Growth...

  15. air-purifying respirator cartridges: Topics by E-print Network

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

    360 RESPIRATION RATES AND LOW-OXYGEN TOLERANCE LIMITS IN SKIPJACK TUNA, KATSUWONUS PELAMIS Environmental Sciences and Ecology Websites Summary: that skipjack tuna ofall sizes...

  16. Metabolic spatial variability in electrode-respiring Geobacter sulfurreducens biofilms

    SciTech Connect (OSTI)

    Renslow, Ryan S.; Babauta, Jerome T.; Dohnalkova, Alice; Boyanov, Maxim I.; Kemner, Kenneth M.; Majors, Paul D.; Fredrickson, Jim K.; Beyenal, Haluk

    2013-06-01T23:59:59.000Z

    Certain bacteria are capable of transferring electrons derived from respiratory metabolism to solid extracellular electron-accepting materials1-4. This ability allows the organisms to use conductive substrata as their sole electron sink, generating electricity that is available for practical applications5-7. Geobacter is a biofilm-forming genus capable of this extracellular electron transfer8-11. Evidence in the literature suggests that Geobacter cells produce a conductive matrix to gain access to electron-accepting surfaces12,13. It has been hypothesized that cells that are more than tens of microns from the electron-accepting surface cannot respire because of electrical resistance in the matrix and thus remain metabolically inactive14-16. To test this hypothesis, we sought to determine whether the entire biofilm remains metabolically active and able to respire on an electron-accepting surface as the biofilm thickness increases. We developed and used a novel electrochemical-nuclear magnetic resonance (EC-NMR) microimaging system capable of sustaining an electrochemically active biofilm on a polarized electrode inside a superconducting magnet, allowing for simultaneous NMR and electrochemical investigation of a biofilm for the first time. Here, we show that Geobacter biofilms can grow to several hundred microns thick while respiring on an electrode and that the top of the biofilm remains metabolically active. This is only possible if the cells near the top are able to transfer electrons through the initial biofilm matrix to the electrode. We used X-ray absorption spectroscopy to verify electron transfer to uranium ions by metabolically active cells near the top of the biofilm. Our results reveal that extracellular electron transfer is not prevented by electrical resistance, even when the biofilm is hundreds of microns thick. Furthermore, the electron donor may be the limiting factor for respiration and the base of the biofilm may be less active despite being in close proximity to the electrode. Long-range electron transfer across metabolically inactive regions within Geobacter biofilms adds a novel facet to our comprehension of electrochemically active biology.

  17. RF design of X-band RF deflector for femtosecond diagnostics of LCLS electron beam

    SciTech Connect (OSTI)

    Dolgashev, Valery A.; Wang Juwen [SLAC National Accelerator Laboratory, Menlo Park, CA, 94025 (United States)

    2012-12-21T23:59:59.000Z

    We designed a successful constant impedance traveling wave X-band rf deflector for electron beam diagnostics at the 14 GeV SLAC Linac Coherent Light Source (LCLS). This is the first practical deflector built with a waveguide coupler. The 1-meter rf deflector produces 24 MeV peak transverse kick when powered with 20 MW of 11.424 GHz rf. The design is based on our experience with high gradient X-band accelerating structures. Several deflectors of this design have been built at SLAC and are currently in use. Here we describe the design and distinguishing features of this device.

  18. Design and fabrication of an RF power LDMOSFET on SOI

    E-Print Network [OSTI]

    Fiorenza, James G. (James George), 1972-

    2002-01-01T23:59:59.000Z

    This thesis studied thin-film Silicon-on-Insulator (SOI) LDMOSFET technology for RF power amplifier applications. To conduct this study, two generations of SOI RF power devices for portable wireless systems were designed ...

  19. analog rf gap: Topics by E-print Network

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

    LHC, particles not captured by the RF system at injection or leaking out of the RF bucket may quench the superconducting magnets during beam abort. The problem, common to other...

  20. Novel rf mems tunable filters with adjustable spurious suppression 

    E-Print Network [OSTI]

    Sekar, Vikram

    2009-05-15T23:59:59.000Z

    This thesis presents the theory and design of fixed and Radio Frequency (RF) Microelectromechanical Systems (MEMS) -based tunable microwave filters for RF and microwave applications. The methodology for the design of coupled resonator filters...

  1. Novel rf mems tunable filters with adjustable spurious suppression

    E-Print Network [OSTI]

    Sekar, Vikram

    2009-05-15T23:59:59.000Z

    This thesis presents the theory and design of fixed and Radio Frequency (RF) Microelectromechanical Systems (MEMS) -based tunable microwave filters for RF and microwave applications. The methodology for the design of coupled resonator filters...

  2. Holographic fractional topological insulators

    SciTech Connect (OSTI)

    Hoyos, Carlos; Jensen, Kristan; Karch, Andreas [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

    2010-10-15T23:59:59.000Z

    We give a holographic realization of the recently proposed low-energy effective action describing a fractional topological insulator. In particular we verify that the surface of this hypothetical material supports a fractional quantum Hall current corresponding to half that of a Laughlin state.

  3. (Carbon isotope fractionation inplants)

    SciTech Connect (OSTI)

    O'Leary, M.H.

    1990-01-01T23:59:59.000Z

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  4. Configurations for short period rf undulators

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

    Kuzikov, S. V.; Jiang, Y.; Marshall, T. C.; Sotnikov, G. V.; Hirshfield, J. L.

    2013-07-01T23:59:59.000Z

    Several configurations for rf undulators energized at millimeter wavelengths and designed to produce coherent nanometer radiation from sub-GeV electron beams are analyzed and compared with one another. These configurations include a traveling-wave resonant ring, a standing wave resonator, and a resonator operating close to cutoff.

  5. RF Breakdown of Metallic Surfaces in Hydrogen

    SciTech Connect (OSTI)

    BastaniNejad, M.; Elmustafa, A.A.; /Old Dominion U.; Yonehara, K.; Chung, M.; Jansson, A.; Hu, M.; Moretti, A.; Popovic, M.; /Fermilab; Alsharo'a, M.; Neubauer, M.; Sah, R.; /Muons Inc., Batavia

    2009-05-01T23:59:59.000Z

    In earlier reports, microscopic images of the surfaces of metallic electrodes used in high-pressure gas-filled 805 MHz RF cavity experiments were used to investigate the mechanism of RF breakdown of tungsten, molybdenum, and beryllium electrode surfaces. Plots of remnants were consistent with the breakdown events being due to field emission, due to the quantum mechanical tunnelling of electrons through a barrier as described by Fowler and Nordheim. In the work described here, these studies have been extended to include tin, aluminium, and copper. Contamination of the surfaces, discovered after the experiments concluded, have cast some doubt on the proper qualities to assign to the metallic surfaces. However, two significant results are noted. First, the maximum stable RF gradient of contaminated copper electrodes is higher than for a clean surface. Second, the addition of as little as 0.01% of SF6 to the hydrogen gas increased the maximum stable gradient, which implies that models of RF breakdown in hydrogen gas will be important to the study of metallic breakdown.

  6. RF Design of the LCLS Gun

    SciTech Connect (OSTI)

    Limborg-Deprey, C

    2010-12-13T23:59:59.000Z

    Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun [1], referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee [2]. Files and reference documents are compiled in Section IV.

  7. Emittance control in rf cavities and solenoids

    E-Print Network [OSTI]

    Eshraqi, Mohammad; Lombardi, Alessandra M

    2009-01-01T23:59:59.000Z

    We study emittance growth for transport of uniform and Gaussian beams of particles in rf cavities and solenoids and show analytically its dependence on initial beam parameters. Analytical results are confirmed with simulation studies over a broad range of different initial beams.

  8. Experimental Study of RF Pulsed Heating

    SciTech Connect (OSTI)

    Laurent, Lisa; Tantawi, Sami; Dolgashev, Valery; Nantista, Christopher; /SLAC; Higashi, Yasuo; /KEK, Tsukuba; Aicheler, Markus; Heikkinen, Samuli; Wuensch, Walter; /CERN

    2011-11-04T23:59:59.000Z

    Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop(reg. sign), copper silver, and silver plated copper. The samples were exposed to different machining and heat treatment processes prior to rf processing. Each sample was tested to a peak pulsed heating temperature of approximately 110 C and remained at this temperature for approximately 10 x 10{sup 6} rf pulses. In general, the results showed the possibility of pushing the gradient limits due to pulsed heating fatigue by the use of copper zirconium and copper chromium alloys.

  9. Commissioning of the MICE RF System

    E-Print Network [OSTI]

    Moss, A.; Stanley, T.; White, C.; Ronald, K.; Whyte, C.G.; Dick, A.J.; Speirs, D.C.; Alsari, S.

    2014-01-01T23:59:59.000Z

    The Muon Ionisation Cooling Experiment (MICE) is being constructed at Rutherford Appleton Laboratory in the UK. The muon beam will be cooled using multiple hydrogen absorbers then reaccelerated using an RF cavity system operating at 201MHz. This paper describes recent progress in commissioning the amplifier systems at their design operation conditions, installation and operation as part of the MICE project.

  10. Advanced RF power sources for linacs

    SciTech Connect (OSTI)

    Wilson, P.B.

    1996-10-01T23:59:59.000Z

    In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

  11. Cw rf operation of the FMIT RFQ

    SciTech Connect (OSTI)

    Fazio, M.V.; Brandeberry, F.E.

    1985-01-01T23:59:59.000Z

    The 80-MHz RFQ for the Fusion Materials Irradiation Test Facility prototype accelerator has been rf conditioned for cw operation to the design field level of 17.5 MV/m (1.68 x Kilpatrick limit). Experimental results and operating experience will be discussed.

  12. Summary We estimated total ecosystem respiration from a ponderosa pine (Pinus ponderosa Dougl. ex Laws.) plantation

    E-Print Network [OSTI]

    Cohen, Ronald C.

    Summary We estimated total ecosystem respiration from a ponderosa pine (Pinus ponderosa Dougl. ex, 1998. We apportioned ecosystem respi- ration among heterotrophic, root, stem and foliage based on re respiration component at selected sampling points, and scaled the mea- surements up to the ecosystem based

  13. Stem respiration in tropical forests along an elevation gradient in the Amazon and Andes

    E-Print Network [OSTI]

    Malhi, Yadvinder

    Stem respiration in tropical forests along an elevation gradient in the Amazon and Andes A M A N D metabolism, resulting in the release of carbon dioxide as a by-product. Little is known of how autotrophic respiration components vary across environmental gradients, particularly in tropical ecosystems. Here, we

  14. Elevated CO2 stimulates grassland soil respiration by increasing carbon inputs rather than by enhancing soil

    E-Print Network [OSTI]

    Minnesota, University of

    Elevated CO2 stimulates grassland soil respiration by increasing carbon inputs rather than It is not clear whether the consistent positive effect of elevated CO2 on soil respiration (soil carbon flux, SCF) results from increased plant and microbial activity due to (i) greater C availability through CO2-induced

  15. CO2 efflux from Amazonian headwater streams represents a significant fate for deep soil respiration

    E-Print Network [OSTI]

    Lehmann, Johannes

    CO2 efflux from Amazonian headwater streams represents a significant fate for deep soil respiration amounts of CO2 to the atmosphere, while the magnitude of CO2 degassing from small streams remains a major was as terrestrially-respired CO2 dissolved within soils, over 90% of which evaded to the atmosphere within headwater

  16. Physical controls on the isotopic composition of soil-respired CO2

    E-Print Network [OSTI]

    Physical controls on the isotopic composition of soil-respired CO2 Nick Nickerson1 and Dave Risk1] Measurement of the isotopic composition of soil and soil-respired CO2 (d13 CO2) has become an invaluable tool in understanding the effects of diffusive transport on soil CO2 isotopic composition, it is crucial

  17. A satellite-based biosphere parameterization for net ecosystem CO2 exchange: Vegetation Photosynthesis and Respiration

    E-Print Network [OSTI]

    Lin, John Chun-Han

    Photosynthesis and Respiration Model (VPRM) Pathmathevan Mahadevan,1 Steven C. Wofsy,1 Daniel M. Matross,1 12 April 2008. [1] We present the Vegetation Photosynthesis and Respiration Model (VPRM), a satellite of ecosystem photosynthesis, and annual sum of NEE at all eddy flux sites for which it is optimized

  18. Analysis of the effects of a proposed rule for the enforcement of respirable dust standards

    E-Print Network [OSTI]

    Britton, Robert Grant

    1996-01-01T23:59:59.000Z

    The effects of a rule for the enforcement of respirable dust standards proposed by the Mine Safety and Health Administration (MSHA) has been evaluated. Respirable coal dust sample data collected over a three year period by a mining company were used...

  19. Frequency and amplitude control for an experimental linac rf drive

    E-Print Network [OSTI]

    Atre, Mahesh Purushottam

    1992-01-01T23:59:59.000Z

    uses a RFQ accelerator/buncher to accelerate a beam of II ions. The 500 keV, 10 mA beam will require approximately 100 kW (peak) rf power at 473 MHz [2]. The basic layout of the linac system is illustrated in Fig. 1. The rf power source uses...-rod structure resonant at 473 MHz. ION SOURCE RF QUADRUPOLE BEAM HIGH POWER RF AMP AMPL CONTROL LOW POWER RF AMP OSC FREQ CONTROL SYSTEM Figure 1. The Experimental Linac System The oscillator uses a phase-locked loop for frequency control...

  20. Summary Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and

    E-Print Network [OSTI]

    Cohen, Ronald C.

    content, and root density and activity, and thus changes soil respiration. We measured soil respiration of thin- ning. Thinning did not change the sensitivity of soil respiration to temperature or to water content, and soil physi- cal and chemical properties, result in high variability in and sensitivity

  1. A discrete fractional random transform

    E-Print Network [OSTI]

    Zhengjun Liu; Haifa Zhao; Shutian Liu

    2006-05-20T23:59:59.000Z

    We propose a discrete fractional random transform based on a generalization of the discrete fractional Fourier transform with an intrinsic randomness. Such discrete fractional random transform inheres excellent mathematical properties of the fractional Fourier transform along with some fantastic features of its own. As a primary application, the discrete fractional random transform has been used for image encryption and decryption.

  2. ILC RF System R and D

    SciTech Connect (OSTI)

    Adolphsen, Chris; /SLAC

    2012-07-03T23:59:59.000Z

    The Linac Group at SLAC is actively pursuing a broad range of R&D to improve the reliability and reduce the cost of the L-band (1.3 GHz) rf system proposed for the ILC linacs. Current activities include the long-term evaluation of a 120 kV Marx Modulator driving a 10 MW Multi-Beam Klystron, design of a second-generation Marx Modulator, testing of a sheet-beam gun and beam transport system for a klystron, construction of an rf distribution system with remotely-adjustable power tapoffs, and development of a system to combine the power from many klystrons in low-loss circular waveguide where it would be tapped-off periodically to power groups of cavities. This paper surveys progress during the past few years.

  3. An Efficient RF Source for Jlab

    SciTech Connect (OSTI)

    Neubauer, M. [Muons, Inc.; Dudas, A. [Muons, Inc.; Rimmer, Robert A. [JLAB; Wang, Haipeng [JLAB

    2013-12-01T23:59:59.000Z

    We propose the development of a highly reliable high efficiency RF source for JLAB with a lower lifetime cost operating at 80% efficiency with system operating costs of about 0.7M$/year for the 6 GeV machine. The design of the RF source will be based upon two injection locked magnetrons in a novel combining architecture for amplitude modulation and a cross field amplifier (CFA) as an output tube for the 12 GeV upgrade. A cost analysis including efficiency and reliability will be performed to determine the optimum system architecture. Several different system architectures will be designed and evaluated for a dual injection locked magnetron source using novel combining techniques and possibly a CFA as the output tube. A paper design for the 1497 MHz magnetron system will be completed. The optimum system architecture with all relevant specifications will be completed so that a prototype can be built.

  4. RUGGED CERAMIC WINDOW FOR RF APPLICATIONS

    SciTech Connect (OSTI)

    MIKE NEUBAUER

    2012-11-01T23:59:59.000Z

    High-current RF cavities that are needed for many accelerator applications are often limited by the power transmission capability of the pressure barriers (windows) that separate the cavity from the power source. Most efforts to improve RF window design have focused on alumina ceramic, the most popular historical choice, and have not taken advantage of new materials. Alternative window materials have been investigated using a novel Merit Factor comparison and likely candidates have been tested for the material properties which will enable construction in the self-matched window configuration. Window assemblies have also been modeled and fabricated using compressed window techniques which have proven to increase the power handling capability of waveguide windows. Candidate materials have been chosen to be used in fabricating a window for high power testing at Thomas Jefferson National Accelerator Facility.

  5. Introduction Final Cooling Channel -High Frequency RF

    E-Print Network [OSTI]

    McDonald, Kirk

    algorithms integration with G4BL on NERSC Integration of twiss calculations with G4BL & Optimization codes Calculation of twiss function inside absorber+RF 0 5 10 15 20 25 0 1 2 3 4 5 6 7 8 9 10 P[GeV/c] z [m] Bz P=0V/c P=0.127 GeV/c In order to match for the field flip one needs to be able to calculate twiss functions

  6. Radio frequency (RF) heated supersonic flow laboratory

    SciTech Connect (OSTI)

    Wantuck, P.; Watanabe, H.

    1990-01-01T23:59:59.000Z

    A unique supersonic flow apparatus which employs an inductively-coupled, radio frequency (RF) torch to supply high enthalpy source gas to the nozzle inlet is described. The main features of this system are the plasma tube, a cooled nozzle assembly, and a combustion/expansion chamber with a heat exchanger. A description of these components with current test data is presented. In addition, a discussion of anticipated experiments utilizing this system is included.

  7. RF Gun Photocathode Research at SLAC

    SciTech Connect (OSTI)

    Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC

    2012-05-16T23:59:59.000Z

    LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

  8. Fractional Variational Iteration Method for Fractional Nonlinear Differential Equations

    E-Print Network [OSTI]

    Guo-cheng Wu

    2010-07-12T23:59:59.000Z

    Recently, fractional differential equations have been investigated via the famous variational iteration method. However, all the previous works avoid the term of fractional derivative and handle them as a restricted variation. In order to overcome such shortcomings, a fractional variational iteration method is proposed. The Lagrange multipliers can be identified explicitly based on fractional variational theory.

  9. Design and Manufacture of the RF Power Supply and RF Transmission Line for SANAEM Project Prometheus

    E-Print Network [OSTI]

    Turemen, G; Unel, G; Alacakir, A

    2015-01-01T23:59:59.000Z

    A 1-5 MeV proton beamline is being built by the Turkish Atomic Energy Authority in collaboration with a number of graduate students from different universities. The most important aspect of the project, is to acquire the design ability and manufacturing capability of all the components locally. SPP will be an accelerator and beam diagnostics test facility and it will also serve the detector development community with its low beam current. This paper discusses the design and construction of the RF power supply and the RF transmission line components such as its waveguide converters and its circulator.

  10. DOE-HDBK-3010-94; DOE Handbook Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume 1

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

    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 DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No Significant Impact610-94 December 1994 CHANGE NOTICE NO. 1

  11. RF Gun cavities cooling regime study. K. Floettmann1

    E-Print Network [OSTI]

    RF power of Pa 68kW corre- sponds to a heat load of 300kW m . To remove such a high heat value from of RF fields in the cavity at an operating frequency is calculated in the usual way. The temperature) with the boundary condition at the RF cavity surface: kc(ngradT) = Ps, (2) where kc = 391 W m·K is the heat

  12. Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    3.0 License. Biogeosciences Soil respiration at mean annualI. L. , and Carvalho, J. E. M. : Effects of soil watercontent on soil res- piration in forests and cattle pastures

  13. Soil organic matter stability and the temperature sensitivity of soil respiration 

    E-Print Network [OSTI]

    Burns, Nancy Rosalind

    2012-11-29T23:59:59.000Z

    Soil respiration is an important source of atmospheric CO2, with the potential for large positive feedbacks with global warming. The size of these feedbacks will depend on the relative sensitivity to temperature of very ...

  14. RESPIRATION RATES AND LOW-OXYGEN TOLERANCE LIMITS IN SKIPJACK TUNA, KATSUWONUS PELAMIS

    E-Print Network [OSTI]

    RESPIRATION RATES AND LOW-OXYGEN TOLERANCE LIMITS IN SKIPJACK TUNA, KATSUWONUS PELAMIS REGINALD M of voluntarily active skipjack tuna, Katsuwonus pelamis, at 23°_24° C were measured in the laboratory from

  15. Fractionation, rearrangement, consolidation, reconstruction

    E-Print Network [OSTI]

    El-Mabrouk, Nadia

    is an innovation. WGD and fractionation are particularly prevalent in flowering plants [6], where the slow (tens itself does not add any new adjacencies or remove any; the pre-existing adjacencies simply continue or by pseudogenization. Even if xy and yz still exist in the homeologous region of the genome, the adjacency xz

  16. argon rf plasma: Topics by E-print Network

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

    you for being so encouraging, for listening to and understanding the woes of RF plasma research, and for being so friendly at conferences and in the hallways. Professor...

  17. Multi-Physics Analysis of the Fermilab Booster RF Cavity

    SciTech Connect (OSTI)

    Awida, M.; Reid, J.; Yakovlev, V.; Lebedev, V.; Khabiboulline, T.; Champion, M.; /Fermilab

    2012-05-14T23:59:59.000Z

    After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

  18. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Anlage, Steven [University of Maryland

    2014-07-23T23:59:59.000Z

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  19. atmospheric rf device: Topics by E-print Network

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

    Tuners with Computationally Efficient Time of Technology, Atlanta, GA 30332 2 Raytheon Company, Tucson AZ, 85734 Abstract -- Modern RF-MEMS device design methods in which...

  20. Active high-power RF switch and pulse compression system

    DOE Patents [OSTI]

    Tantawi, Sami G. (San Mateo, CA); Ruth, Ronald D. (Woodside, CA); Zolotorev, Max (Mountain View, CA)

    1998-01-01T23:59:59.000Z

    A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

  1. Locking Lasers to RF in an Ultra Fast FEL

    E-Print Network [OSTI]

    Wilcox, R.

    2011-01-01T23:59:59.000Z

    Lasers to RF in an Ultrafast FEL R. B . Wilcox, G . Huang,the X-ray pulses from the FEL. The phase-locked loop on the

  2. A new microphonics measurement method for superconducting RF...

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

    new microphonics measurement method for superconducting RF cavities Re-direct Destination: Mechanical vibrations of the superconducting cavity, also known as microphonics, cause...

  3. MICROBIAL RESPIRATION RESPONSE TO C, N, AND P AVAILABILITY IN LOBLOLLY PINE FOREST SOILS 

    E-Print Network [OSTI]

    Whisenant, Justin

    2011-05-05T23:59:59.000Z

    MICROBIAL RESPIRATION RESPONSE TO N AND P AVAILABILITY IN LOBLOLLY PINE FOREST SOILS Major: Forest Management Spatial Science April 2011 Submitted to the Office of Undergraduate Research Texas A&M University in partial... fulfillment of the requirements for the designation as UNDERGRADUATE RESEARCH SCHOLAR A Senior Scholars Thesis by JUSTIN M. WHISENANT A Senior Scholars Thesis by JUSTIN M. WHISENANT MICROBIAL RESPIRATION RESPONSE TO N AND P AVAILABILITY...

  4. Computer control of rf at SLAC

    SciTech Connect (OSTI)

    Schwarz, H.D.

    1985-03-01T23:59:59.000Z

    The Stanford Linear Accelerator is presently upgraded for the SLAC Linear Collider project. The energy is to be increased from approximately 31 GeV to 50 GeV. Two electron beams and one positron beam are to be accelerated with high demands on the quality of the beams. The beam specifications are shown. To meet these specifications, all parameters influencing the beams have to be under tight control and continuous surveillance. This task is accomplished by a new computer system implemented at SLAC which has, among many other functions, control over rf accelerating fields. 13 refs., 8 figs., 2 tabs.

  5. RF Micro Devices | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I GeothermalPotentialBiopowerSolidGenerationMethodInformationeNevada <REC SolarRFMD Jump to:RF Micro

  6. Sandia National Laboratories: RF & Photonics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitche Home AboutMeeting: ProgramFebruaryJunePowerProjectsQuantumRF

  7. Pulse-Density Modulation for RF Applications: The Radio-Frequency Power Amplifier (RF PA)

    E-Print Network [OSTI]

    Sanders, Seth

    . This enables complex digital processing and control of RF switching waveforms. Trends in processing speed demonstrates, techniques previously used for audio amplifiers, motor control, and power conversion may now generations of CMOS technology. We implement digital control of the carrier amplitude using pulse

  8. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01T23:59:59.000Z

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  9. Temperature-associated increases in the global soil respiration record

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin; Thomson, Allison M.

    2010-03-25T23:59:59.000Z

    Soil respiration (RS), the flux of CO2 from the soil surface to the atmosphere, comprises the second-largest terrestrial carbon flux, but its dynamics are incompletely understood, and the global flux remains poorly constrained. Ecosystem warming experiments, modelling analyses, and biokinetics all suggest that RS should change with climate. This has been difficult to confirm observationally because of the high spatial variability of RS, inaccessibility of the soil medium, and inability of remote sensing instruments to measure large-scale RS fluxes. Given these constraints, is it possible to discern climate-driven changes in regional or global RS fluxes in the extant four-decade record of RS chamber measurements? Here we use a database of worldwide RS observations, matched with high-resolution historical climate data, to show a previously unknown temporal trend in the RS record after accounting for mean annual climate, leaf area, nitrogen deposition, and changes in CO2 measurement technique. Air temperature anomaly (deviation from the 1961-1990 mean) is significantly and positively correlated with changes in RS fluxes; both temperature and precipitation anomalies exert effects in specific biomes. We estimate that the current (2008) annual global RS flux is 98±12 Pg and has increased 0.1 Pg yr-1 over the last 20 years, implying a global RS temperature response (Q10) of 1.5. An increasing global RS flux does not necessarily constitute a positive feedback loop to the atmosphere; nonetheless, the available data are consistent with an acceleration of the terrestrial carbon cycle in response to global climate change.

  10. RF Power Degradation of GaN High Electron Mobility Transistors

    E-Print Network [OSTI]

    Joh, Jungwoo

    We have developed a versatile methodology to systematically investigate the RF reliability of GaN High-Electron Mobility Transistors. Our technique utilizes RF and DC figures of merit to diagnose the degradation of RF ...

  11. COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: I. QUASILINEAR THEORY

    E-Print Network [OSTI]

    Kaganovich, Igor

    COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: I. QUASILINEAR THEORY Yu.M. Aliev1 , I an interest in mechanisms of electron heating and power deposition in the plasma main- tained by radio{frequency (rf) electric elds. A modern trend in plasma technology aims at decreasing the gas pressures down

  12. Cooling at the quantum limit and RF refrigeration

    E-Print Network [OSTI]

    Fominov, Yakov

    Cooling at the quantum limit and RF refrigeration Jukka Pekola Low Temperature Laboratory, Helsinki) Francesco Giazotto (SNS Pisa) Yuri Pashkin (NEC) #12;Outline Electronic refrigeration Classical vs quantum (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single

  13. IBM Systems and Technology IBM 7RF SOI

    E-Print Network [OSTI]

    switches, antenna tuners, low noise amplifiers and power amplifiers found in the front end of today distortion device (LowD) option: Boosts performance of the 7RF SOI offering and enables designers to further smartphone radio com- plexity with a silicon offering optimized for RF front-end applications Reduce area

  14. RF cavity using liquid dielectric for tuning and cooling

    DOE Patents [OSTI]

    Popovic, Milorad (Warrenville, IL); Johnson, Rolland P. (Newport News, VA)

    2012-04-17T23:59:59.000Z

    A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

  15. RF-MEMS capacitive switches with high reliability

    DOE Patents [OSTI]

    Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

    2013-09-03T23:59:59.000Z

    A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

  16. Hydrogen-filled RF Cavities for Muon Beam Cooling

    SciTech Connect (OSTI)

    CHARLES, Ankenbrandt

    2009-04-17T23:59:59.000Z

    Ionization cooling requires low-Z energy absorbers immersed in a strong magnetic field and high-gradient, large-aperture RF cavities to be able to cool a muon beam as quickly as the short muon lifetime requires. RF cavities that operate in vacuum are vulnerable to dark-current- generated breakdown, which is exacerbated by strong magnetic fields, and they require extra safety windows that degrade cooling, to separate RF regions from hydrogen energy absorbers. RF cavities pressurized with dense hydrogen gas will be developed that use the same gas volume to provide the energy absorber and the RF acceleration needed for ionization cooling. The breakdown suppression by the dense gas will allow the cavities to operate in strong magnetic fields. Measurements of the operation of such a cavity will be made as functions of external magnetic field and charged particle beam intensity and compared with models to understand the characteristics of this technology and to develop mitigating strategies if necessary.

  17. Proposal for high pressure RF cavity test in the MTA

    SciTech Connect (OSTI)

    Yonehara, K.; /Fermilab

    2010-09-01T23:59:59.000Z

    In order to demonstrate the feasibility of high pressure hydrogen gas filled RF (HPRF) cavities for muon ionization cooling, an HPRF cavity must be tested with a high intensity charged beam. When an HPRF cavity is irradiated with an intense beam each incident particle generates about 1000 electrons and ions per cubic centimeter in a high pressure cavity via ionization. These ionization electrons are influenced by the RF field and the RF quality factor goes down. This Q factor reduction will be a problem with a multi bunch beam, e.g., a muon beam for a muon collider consists of a 12 to 20 bunch train beam with 5 ns timing gap. Thus, the RF field must recover in few nano seconds. We propose to use a 400 MeV proton beam in the MTA and measure a beam loading effect in the HPRF cavity and study the recovery mechanism of the RF field.

  18. SUPERCONDUCTING RF-DIPOLE DEFLECTING AND CRABBING CAVITIES

    SciTech Connect (OSTI)

    Delayen, Jean [ODU, JLAB; De Silva, Paygalage Subashini [ODU, JLAB

    2013-09-01T23:59:59.000Z

    Recent interests in designing compact deflecting and crabbing structures for future accelerators and colliders have initiated the development of novel rf structures. The superconducting rf-dipole cavity is one of the first compact designs with attractive properties such as higher gradients, higher shunt impedance, the absence of lower order modes and widely separated higher order modes. Two rf-dipole designs of 400 MHz and 499 MHz have been designed, fabricated and tested as proof-of-principle designs of compact deflecting and crabbing cavities for the LHC high luminosity upgrade and Jefferson Lab 12 GeV upgrade. The first rf tests have been performed on the rf-dipole geometries at 4.2 K and 2.0 K in a vertical test assembly with excellent results. The cavities have achieved high gradients with high intrinsic quality factors, and multipacting levels were easily processed.

  19. The electrical and lumen output characteristics of an RF lamp

    SciTech Connect (OSTI)

    Alexandrovich, B.M.; Godyak, V.A.; Piejak, R.B. [Osram Sylvania Inc., Beverly, MA (United States)

    1996-12-31T23:59:59.000Z

    Low pressure rf discharges have been studied for over a century. Their first practical application for lighting was proposed by Tesla in 1891. Since then hundreds of patents have been published attempting to implement rf lighting. However, progress in understanding rf discharge phenomena (mostly driven by plasma processing needs) and dramatic improvement in the performance/cost ratio of rf power sources have recently opened the door for development of rf light sources. Today commercial inductively coupled electrodeless lamps are offered by Matsuhita, Philips and GE. In this work the authors present measurements of the electrical characteristics and lumen output from a 2.65 MHz driven inductively coupled light source. Measurements were made on a spherical lamp of 3.125 inch diameter with a re-entrant cavity that houses a cylindrical ferrite core around which is wrapped the primary coil.

  20. Upgrade of the cryogenic CERN RF test facility

    SciTech Connect (OSTI)

    Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B. [CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Koettig, T. [ESS - European Spallation Source, Box 176, 221 00 Lund (Sweden)

    2014-01-29T23:59:59.000Z

    With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990’s in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one and then two horizontal test benches for RF cryomodules operating at 4.5 K in saturated helium. CERN is presently working on the upgrade of its accelerator infrastructure, which requires new superconducting cavities operating below 2 K in saturated superfluid helium. Consequently, the RF test facility has been renewed in order to allow efficient cavity and cryomodule tests in superfluid helium and to improve its thermal performances. The new RF test facility is described and its performances are presented.

  1. High-power RF testing of a 352-MHZ fast-ferrite RF cavity tuner at the Advanced Photon Source.

    SciTech Connect (OSTI)

    Horan, D.; Cherbak, E.; Accelerator Systems Division (APS)

    2006-01-01T23:59:59.000Z

    A 352-MHz fast-ferrite rf cavity tuner, manufactured by Advanced Ferrite Technology, was high-power tested on a single-cell copper rf cavity at the Advanced Photon Source. These tests measured the fast-ferrite tuner performance in terms of power handling capability, tuning bandwidth, tuning speed, stability, and rf losses. The test system comprises a single-cell copper rf cavity fitted with two identical coupling loops, one for input rf power and the other for coupling the fast-ferrite tuner to the cavity fields. The fast-ferrite tuner rf circuit consists of a cavity coupling loop, a 6-1/8-inch EIA coaxial line system with directional couplers, and an adjustable 360{sup o} mechanical phase shifter in series with the fast-ferrite tuner. A bipolar DC bias supply, controlled by a low-level rf cavity tuning loop consisting of an rf phase detector and a PID amplifier, is used to provide a variable bias current to the tuner ferrite material to maintain the test cavity at resonance. Losses in the fast-ferrite tuner are calculated from cooling water calorimetry. Test data will be presented.

  2. Solvent Fractionation of Lignin

    SciTech Connect (OSTI)

    Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL

    2014-01-01T23:59:59.000Z

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. The major issues for the commercial production of value added high performance lignin products are lignin s physical and chemical heterogenities. To overcome these problems, a variety of procedures have been developed to produce pure lignin suitable for high performace applications such as lignin-derived carbon materials. However, most of the isolation procedures affect lignin s properties and structure. In this chapter, a short review of the effect of solvent fractionation on lignin s properties and structure is presented.

  3. Fractional channel multichannel analyzer

    DOE Patents [OSTI]

    Brackenbush, L.W.; Anderson, G.A.

    1994-08-23T23:59:59.000Z

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynchronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board. 9 figs.

  4. LHC RF System Time-Domain Simulation

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; /SLAC

    2010-09-14T23:59:59.000Z

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  5. Characterization of an RF plasma ion source for ion implantation

    SciTech Connect (OSTI)

    Kopalidis, Peter M.; Wan Zhimin [Advanced Ion Beam Technology Inc., 47370 Fremont Blvd., Fremont, CA 94538 (United States)

    2012-11-06T23:59:59.000Z

    A novel inductively coupled RF plasma ion source has been developed for use in a beamline ion implanter. Ion density data have been taken with an array of four Langmuir probes spaced equally at the source extraction arc slit. These provide ion density uniformity information as a function of source pressure, RF power and gas mixture composition. In addition, total extracted ion beam current data are presented for the same conditions. The comparative advantages of the RF source in terms of higher beam current, reduced maintenance and overall productivity improvement compared to a hot cathode source are discussed.

  6. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect (OSTI)

    Qian, Di; Bottomley, Paul A. [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); El-Sharkawy, AbdEl-Monem M.; Edelstein, William A., E-mail: w.edelstein@gmail.com [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 (United States)

    2013-12-15T23:59:59.000Z

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ?3%. With the torso landmarked at the xiphoid, human adult whole?body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.

  7. Communication methods, systems, apparatus, and devices involving RF tag registration

    DOE Patents [OSTI]

    Burghard, Brion J. (W. Richland, WA); Skorpik, James R. (Kennewick, WA)

    2008-04-22T23:59:59.000Z

    One technique of the present invention includes a number of Radio Frequency (RF) tags that each have a different identifier. Information is broadcast to the tags from an RF tag interrogator. This information corresponds to a maximum quantity of tag response time slots that are available. This maximum quantity may be less than the total number of tags. The tags each select one of the time slots as a function of the information and a random number provided by each respective tag. The different identifiers are transmitted to the interrogator from at least a subset of the RF tags.

  8. Stability of barrier buckets with zero RF-barrier separations

    SciTech Connect (OSTI)

    Ng, K.Y.; /Fermilab

    2005-03-01T23:59:59.000Z

    A barrier bucket with very small separation between the rf barriers (relative to the barrier widths) or even zero separation has its synchrotron tune decreasing rather slowly from a large value towards the boundary of the bucket. As a result, large area at the bucket edges can become unstable under the modulation of rf voltage and/or rf phase. In addition, chaotic regions may form near the bucket center and extend outward under increasing modulation. Application is made to those barrier buckets used in the process of momentum mining at the Fermilab Recycler Ring.

  9. Design studies for the LCLS 120 Hz RF gun

    SciTech Connect (OSTI)

    Wang, X.J.; Babzien, M.; Ben-Zvi, I.; Chang, X.Y.; Pjerov, S.; Woodle, M.

    2000-11-01T23:59:59.000Z

    A preliminary design studies were carried out at Brookhaven National Laboratory for a photocathode RF gun injection system for LCLS 120 Hz operation. The starting point for the design is 50 Hz BNL Gun IV developed by a BNL/KEK/SHI collaboration. The basic parameters of the 120 Hz gun is discussed in this report. The complete photocathode RF gun injection system is described for a 120 Hz operation. The injector system includes photocathode RF gun, emittance compensation solenoid magnet, laser system and laser beam delivery system, and electron beam diagnostics. The basic design parameters, mechanical modification and the performance will be presented in this report.

  10. MICROBIAL RESPIRATION RESPONSE TO C, N, AND P AVAILABILITY IN LOBLOLLY PINE FOREST SOILS

    E-Print Network [OSTI]

    Whisenant, Justin

    2011-05-05T23:59:59.000Z

    to an ecosystem by plants is commonly known as net primary production (NPP). Some of this C, having first been converted to sugars, is returned to the atmosphere directly by the plants as a result of normal metabolism (i.e. respiration). Much of the remainder... and the NPP of an ecosystem is largely due to soil microbial respiration. Decomposition of soil organic matter (SOM) by microbes is a metabolic process that results in a release of CO2 gas. Combined with the CO2 emitted by plant roots, this is known...

  11. The heritability of daily ranges in rectal temperature, respiration rate, and pulse rate in lactating cows 

    E-Print Network [OSTI]

    Vega C., Eduardo Humberto

    1957-01-01T23:59:59.000Z

    the data were oolleoted. K. ghly significant oorrelations of temperature with stags of lactation and of respiration with stage of lactation were found among Jerseys, among Holsteins highly significant correlations were found as follows: temperature... in rectal temperature can be expla. 'mod on '. hs basis of the regression of this variable on stage of lactation~ while 10. 5T of the variation in the daily range in respiration rate ca; be explain. d on the basis of the regress'. i n of dai&~ range...

  12. The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems

    SciTech Connect (OSTI)

    Guo, Jiquan; /SLAC

    2009-03-20T23:59:59.000Z

    In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an element capable of switching hundreds of megawatts of RF power in a short time compared to the compressed pulse width is still an open problem. In this dissertation, we present a switch module composed of an active window based on the bulk effects in semiconductor, a circular waveguide three-port network and a movable short plane, with the capability to adjust the S-parameters before and after switching. The RF properties of the switch module were analyzed. We give the scaling laws of the multiple-element switch systems, which allow the expansion of the system to a higher power level. We present a novel overmoded design for the circular waveguide three-port network and the associated circular-to-rectangular mode-converter. We also detail the design and synthesis process of this novel mode-converter. We demonstrate an electrically controlled ultra-fast high power X-band RF active window built with PIN diodes on high resistivity silicon. The window is capable of handling multi-megawatt RF power and can switch in 2-300ns with a 1000A current driver. A low power active pulse compression experiment was carried out with the switch module and a 375ns resonant delay line, obtaining 8 times compression gain with a compression ratio of 20.

  13. Recent Developments in Nonregular Fractional Factorial Designs

    E-Print Network [OSTI]

    Xu, H Q; Phoa, Frederick; Wong, W K

    2008-01-01T23:59:59.000Z

    fractional factorial designs and their applications. Ann.nonregular fractional factorial designs. Metrika, 62, 73-83.The 2 k?p fractional factorial designs. Technometrics, 3,

  14. Recent Developments in Nonregular Fractional Factorial Designs

    E-Print Network [OSTI]

    Hongquan Xu; Frederick K. H. Phoa; Weng Kee Wong

    2011-01-01T23:59:59.000Z

    fractional factorial designs and their applications. Ann.nonregular fractional factorial designs. Metrika, 62, 73-83.The 2 k?p fractional factorial designs. Technometrics, 3,

  15. ECE 331 -Biomedical Instrumentation Department of Electrical & Computer Engineering, UBC EKG Derived Respiration / Rate (EDR/R)

    E-Print Network [OSTI]

    Pulfrey, David L.

    EKG Derived Respiration / Rate (EDR/R) Due: Start of NEXT Class (collect all data during lab) An EKG between the cardiac vector and the EKG pads. This change modifies the amplitude of the EKG signal. EDR which is respiration. EDR is monitored using the IVY patient monitor by selecting "Impedance

  16. Recent Progress of RF Cavity Study at Mucool Test Area

    SciTech Connect (OSTI)

    Yonehara, Katsuya; /Fermilab

    2011-12-02T23:59:59.000Z

    Summar of presentation is: (1) MTA is a multi task working space to investigate RF cavities for R&D of muon beam cooling channel - (a) Intense 400 MeV H{sup -} beam, (b) Handle hydrogen (flammable) gas, (c) 5 Tesla SC solenoid magnet, (d) He cryogenic/recycling system; (2) Pillbox cavity has been refurbished to search better RF material - Beryllium button test will be happened soon; (3) E x B effect has been tested in a box cavity - Under study (result seems not to be desirable); (4) 201 MHz RF cavity with SRF cavity treatment has been tested at low magnetic field - (a) Observed some B field effect on maximum field gradient and (b) Further study is needed (large bore SC magnet will be delivered end of 2011); and (5) HPRF cavity beam test has started - (a) No RF breakdown observed and (b) Design a new HPRF cavity to investigate more plasma loading effect.

  17. Electrodeless lighting RF power source development. Final report

    SciTech Connect (OSTI)

    NONE

    1996-08-30T23:59:59.000Z

    An efficient, solid state RF power source has been developed on this NICE project for exciting low power electrodeless lamp bulbs. This project takes full advantage of concurrent advances in electrodeless lamp technology. Electrodeless lamp lighting systems utilizing the sulfur based bulb type developed by Fusion Lighting, Inc., is an emerging technology which is based on generating light in a confined plasma created and sustained by RF excitation. The bulb for such a lamp is filled with a particular element and inert gas at low pressure when cold. RF power from the RF source creates a plasma within the bulb which reaches temperatures approaching those of high pressure discharge lamp plasmas. At these temperatures the plasma radiates substantial visible light with a spectrum similar to sunlight.

  18. accelerating rf station: Topics by E-print Network

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

    designed as 450 Omega . The RF power is fed by 1 kW solid state amplifier using a step-up transformer with 1:9 impedance ratio. In the high power test, an accelerating gap voltage...

  19. RF Thermal Plasma Synthesis of Ferrite Nanopowders from Metallurgical Wastes

    E-Print Network [OSTI]

    Gubicza, Jenő

    that of ferrites synthesized by the conventional ceramic route. Introduction Radiofrequency (RF) thermal plasmas by X-ray diffraction (XRD) using a Philips Xpert diffractometer and CuK radiation (=0.15418 nm

  20. Rf System Requirements for JLab’s MEIC Collider Ring

    SciTech Connect (OSTI)

    Wang, Shaoheng [JLAB; Li, Rui [JLAB; Rimmer, Robert A. [JLAB; Wang, Haipeng [JLAB; Zhang, Yuhong [JLAB

    2013-06-01T23:59:59.000Z

    The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. At the top energy are the electron and ion collider rings. For the ion ring, it accelerates five long ion bunches to colliding energy and rebunches ions into a train of very short bunches before colliding. A set of low frequency RF system is needed for the long ion bunch energy ramping. Another set of high frequency RF cavities is needed to rebunch ions. For the electron ring, superconducting RF (SRF) cavities are needed to compensate the synchrotron radiation energy loss. The impedance of the SRF cavities must be low enough to keep the high current electron beam stable. The preliminary design requirements of these RF cavities are presented.

  1. RF Sputtering for preparing substantially pure amorphous silicon monohydride

    DOE Patents [OSTI]

    Jeffrey, Frank R. (Ames, IA); Shanks, Howard R. (Ames, IA)

    1982-10-12T23:59:59.000Z

    A process for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicon produced by reactive rf sputtering of an amorphous silicon target. There is provided a chamber with an amorphous silicon target and a substrate therein with the substrate and the target positioned such that when rf power is applied to the target the substrate is in contact with the sputtering plasma produced thereby. Hydrogen and argon are fed to the chamber and the pressure is reduced in the chamber to a value sufficient to maintain a sputtering plasma therein, and then rf power is applied to the silicon target to provide a power density in the range of from about 7 watts per square inch to about 22 watts per square inch to sputter an amorphous silicon hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

  2. BN/Graphene/BN Transistors for RF Applications

    E-Print Network [OSTI]

    Taychatanapat, Thiti

    In this letter, we demonstrate the first BN/graphene/BN field-effect transistor for RF applications. This device structure can preserve the high mobility and the high carrier velocity of graphene, even when it is sandwiched ...

  3. Printed Low Power Amperometric Gas Sensors Employing RF Energy Harvesting

    E-Print Network [OSTI]

    Hochberg, Michael

    Printed Low Power Amperometric Gas Sensors Employing RF Energy Harvesting M. T. Cartera , J. R Seattle, WA 98195-2350, USA We will report on some new types of low power amperometric gas sensors

  4. Electrical degradation mechanisms of RF power GaAs PHEMTs

    E-Print Network [OSTI]

    Villanueva, Anita A. (Anita Ariel), 1978-

    2007-01-01T23:59:59.000Z

    GaAs Pseudomorphic High-Electron Mobility Transistors (PHEMTs) are widely used in RF power applications. Since these devices typically operate at high power levels and under high voltage biasing, their electrical reliability ...

  5. CMOS RF Power Amplifier Design for Wireless Communications

    E-Print Network [OSTI]

    FANG, Qiang

    2012-01-01T23:59:59.000Z

    conjugate (S22) match (solid curve) and power match (dashedSupply Linear RF Power Amplifier", IEEE J. Solid-State Circ.Fully-integrated CMOS Power Amplifiers", IEEE J. Solid-State

  6. Progress on the Mice 201 MNz RF Cavity at LBNL

    E-Print Network [OSTI]

    Luo, Tianhuan

    2014-01-01T23:59:59.000Z

    like to thank people at LBNL EH&S and Main Machine Shop forMICE 201 MHz RF CAVITY AT LBNL* Tianhuan Luol, Don Summers,Virostek, Michael Zisman, LBNL, Berkeley, CA 94720, USA

  7. DESIGN OF A DC/RF PHOTOELECTRON GUN.

    SciTech Connect (OSTI)

    YU,D.NEWSHAM,Y.SMIRONOV,A.YU,J.SMEDLEY,J.SRINIVASAN RAU,T.LEWELLEN,J.ZHOLENTS,A.

    2003-05-12T23:59:59.000Z

    An integrated dc/rf photoelectron gun produces a low-emittance beam by first rapidly accelerating electrons at a high gradient during a short ({approx}1 ns), high-voltage pulse, and then injecting the electrons into an rf cavity for subsequent acceleration. Simulations show that significant improvement of the emittance appears when a high field ({approx} 0.5-1 GV/m) is applied to the cathode surface. An adjustable dc gap ({le} 1 mm) which can be integrated with an rf cavity is designed for initial testing at the Injector Test Stand at Argonne National Laboratory using an existing 70-kV pulse generator. Plans for additional experiments of an integrated dc/rf gun with a 250-kV pulse generator are being made.

  8. RF Pulse Design for Parallel Excitation in Magnetic Resonance Imaging 

    E-Print Network [OSTI]

    Liu, Yinan

    2012-07-16T23:59:59.000Z

    , such as accelerating imaging speed, mitigating field inhomogeneity in high-field MRI, and alleviating the susceptibility artifact in functional MRI (fMRI). In these applications, controlling radiofrequency (RF) power deposition (quantified by Specific Absorption Rate...

  9. RF-MEMS Switched Varactors for Medium Power Applications

    E-Print Network [OSTI]

    Maury, F; Crunteanu, A; Conseil, F; Blondy, P

    2008-01-01T23:59:59.000Z

    In RF (Radio Frequency) domain, one of the limitations of using MEMS (Micro Electromechanical Systems) switching devices for medium power applications is RF power. Failure phenomena appear even for 500 mW. A design of MEMS switched capacitors with an enhanced topology is presented in this paper to prevent it. This kind of device and its promising performances will serve to fabricate a MEMS based phase shifter able to work under several watts.

  10. Measurement of current distribution on RF coils using MR imaging 

    E-Print Network [OSTI]

    Wu, Yu

    1993-01-01T23:59:59.000Z

    MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1993 Major Subject' Electrical Engineering MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to Texas ASM University in partial fulfillment of the requirments for the degree of MASTER OF SCIENCE...

  11. Incompressible Stars and Fractional Derivatives

    E-Print Network [OSTI]

    S. S. Bayin; J. P. Krisch

    2014-08-21T23:59:59.000Z

    Fractional calculus is an effective tool in incorporating the effects of non-locality and memory into physical models. In this regard, successful applications exist rang- ing from signal processing to anomalous diffusion and quantum mechanics. In this paper we investigate the fractional versions of the stellar structure equations for non radiating spherical objects. Using incompressible fluids as a comparison, we develop models for constant density Newtonian objects with fractional mass distributions or stress conditions. To better understand the fractional effects, we discuss effective values for the density, gravitational field and equation of state. The fractional ob- jects are smaller and less massive than integer models. The fractional parameters are related to a polytropic index for the models considered.

  12. Warming and Intensified Summer Drought Influence Leaf Dark Respiration and Related Plant Traits in Three Dominant Species of the Southern Oak Savanna

    E-Print Network [OSTI]

    Lindgren, Kourtnee Marr

    2011-08-08T23:59:59.000Z

    The short-term temperature-response of dark respiration may be altered by climate warming through temperature acclimation; however the role of drought in influencing thermal acclimation is not known. We hypothesized that leaf dark respiration...

  13. COMPARISON OF RF CAVITY TRANSPORT MODELS FOR BBU SIMULATIONS

    SciTech Connect (OSTI)

    Ilkyoung Shin,Byung Yunn,Todd Satogata,Shahid Ahmed

    2011-03-01T23:59:59.000Z

    The transverse focusing effect in RF cavities plays a considerable role in beam dynamics for low-energy beamline sections and can contribute to beam breakup (BBU) instability. The purpose of this analysis is to examine RF cavity models in simulation codes which will be used for BBU experiments at Jefferson Lab and improve BBU simulation results. We review two RF cavity models in the simulation codes elegant and TDBBU (a BBU simulation code developed at Jefferson Lab). elegant can include the Rosenzweig-Serafini (R-S) model for the RF focusing effect. Whereas TDBBU uses a model from the code TRANSPORT which considers the adiabatic damping effect, but not the RF focusing effect. Quantitative comparisons are discussed for the CEBAF beamline. We also compare the R-S model with the results from numerical simulations for a CEBAF-type 5-cell superconducting cavity to validate the use of the R-S model as an improved low-energy RF cavity transport model in TDBBU. We have implemented the R-S model in TDBBU. It will improve BBU simulation results to be more matched with analytic calculations and experimental results.

  14. High power RF systems for the BNL ERL project

    SciTech Connect (OSTI)

    Zaltsman, A.; Lambiase, R.

    2011-03-28T23:59:59.000Z

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  15. R&D ERL: High power RF systems

    SciTech Connect (OSTI)

    Zaltsman, A.

    2010-01-15T23:59:59.000Z

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2.5 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  16. Minimization of Fractional Power Densities

    E-Print Network [OSTI]

    Minimization of Fractional Power Densities. Robert Hardt, Rice University. Abstract: A k dimensional rectifiable current is given by an oriented k dimensional

  17. Fishery Bulletin, Vol. 79, No. 1 Gooding, Reginald M., William H. Neill, and Andrew E. Dizon, "Respiration rates and low-oxygen

    E-Print Network [OSTI]

    , "Respiration rates and low-oxygen tolerance limits in skipjack tuna, Katsuwonus pelamis:' p. 31-48. 1) Page 31

  18. Fractional Method of Characteristics for Fractional Partial Differential Equations

    E-Print Network [OSTI]

    Guo-cheng Wu

    2010-07-10T23:59:59.000Z

    The method of characteristics has played a very important role in mathematical physics. Preciously, it was used to solve the initial value problem for partial differential equations of first order. In this paper, we propose a fractional method of characteristics and use it to solve some fractional partial differential equations.

  19. A deeper respired carbon pool in the glacial equatorial Pacific Ocean L.I. Bradtmiller a,

    E-Print Network [OSTI]

    Sachs, Julian P.

    A deeper respired carbon pool in the glacial equatorial Pacific Ocean L.I. Bradtmiller a, , R in paleoceanography. We present evidence from ten equatorial Pacific Ocean sediment cores to show that the deep Pacific Ocean likely stored more carbon during the last glacial period than the Holocene

  20. I am delighted to announce the publication, in Ad-vances in Photosynthesis and Respiration (AIPH)

    E-Print Network [OSTI]

    Govindjee "Gov"

    I am delighted to announce the publication, in Ad- vances in Photosynthesis and Respiration (AIPH-Clermont and Sabeeha Mer- chant); and Volume 14 (Photosynthesis in Algae, edited by Anthony Larkum, Susan Douglas-7923-3682-8); Volume 3: Biophysical Techniques in Photosynthesis (24 Chapters; 411 pages; 1996; edited by the late Jan

  1. Photosynthesis & Respiration 2009 1 Minority Science Programs School of Biological Sciences University of California, Irvine

    E-Print Network [OSTI]

    Rose, Michael R.

    Photosynthesis & Respiration 2009 1 Minority Science Programs ­ School of Biological Sciences" hetero = "another" 2. During photosynthesis, plants and phytoplankton use energy from the sun to combine: An anacharis plant in water produces oxygen when it photosynthesizes. 3. Photosynthesis takes place within

  2. Modeling soil respiration based on carbon, nitrogen, and root mass across diverse Great Lake forests

    E-Print Network [OSTI]

    Chen, Jiquan

    . Introduction Linkages between atmospheric carbon dioxide and global thermal properties have forcedModeling soil respiration based on carbon, nitrogen, and root mass across diverse Great Lake the examination of biospheric carbon flows and pools. Variability in carbon storage or the net ecosystem exchange

  3. Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired carbon

    E-Print Network [OSTI]

    Litvak, Marcy

    Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired boreal peat under black spruce forest with sphagnum and feather moss understory using incubation increments. At temperatures below 0°C, significant decomposition was observed in feather moss peat

  4. Microbial Respiration and Its Consequences on Oxygen Availability in Peat Substrate

    E-Print Network [OSTI]

    Boyer, Edmond

    91 Microbial Respiration and Its Consequences on Oxygen Availability in Peat Substrate R. Naasz, J to Horticulture 2, rue Le Nôtre, F-49045 Angers Cedex 01 France Keywords: peat, oxygen uptake, microorganisms (Sphagnum peat) on oxygen transport and availability to the root. This is why, a one-dimensional transfer

  5. ECG-Derived Respiration: Comparison and New Measures for Respiratory Variability

    E-Print Network [OSTI]

    During ECG recording, several methods can be applied to derive a respiratory signal from the ECG (EDR signal). In this paper 4 EDR methods, including ECG filtering, R and RS amplitude based techniques-derived respiration or EDR signals and arise from the movement of electrodes with respect to the heart during

  6. Application of Kernel Principal Component Analysis for Single Lead ECG-Derived Respiration

    E-Print Network [OSTI]

    signal from ECGs. In this study, an improved ECG-derived respiration (EDR) algorithm based on kernel PCA function (RBF) kernel performs the best when deriving EDR signals. Further improvement is carried outPCA is assessed by comparing the EDR signals to a reference respiratory signal, using the correlation

  7. Z .Geoderma 82 1998 83114 The isotopic composition of soil and soil-respired

    E-Print Network [OSTI]

    Amundson, Ronald

    investigated for the past three decades by earth2 scientists in a variety of disciplines. Carbon dioxide due to the magnitude of soil2 respiration on a global scale, and its role in the processes controlling.V. All rights reserved. Z .PII S0016-7061 97 00098-0 #12;( )R. Amundson et al.rGeoderma 82 1998 83

  8. Use of MAG-1 spectacles with positive- and negative-pressure respirators

    SciTech Connect (OSTI)

    Reed, K.A.; Moore, T.O.

    1985-02-01T23:59:59.000Z

    Results of testing conducted at Los Alamos National Laboratory, Personnel Protection Studies Section, using MAG-1 spectacles in conjunction with positive- and negative-pressure full-facepiece respirators, are reported. The purpose of the three-phase study was to determine if the specially constructed strap of the MAG-1s affected the protection factors (PFs) of the respirators or the cylinder life of selected self-contained breathing apparatus (SCBA). The following respirators were tested with the MAG-1s: (1) Phases I and II, positive-pressure full facepiece: Presur-Pak II SCBA (pressure-demand) Scottoramic facepiece, MSA 401 Air Mask Ultravue facepiece (medium), Survivair pressure-demand SCBA/silicone full facepiece, MSA powered air-purifying respirator/Ultravue facepiece (medium); and (2) Phase III, negative-pressure full facepiece: MSA Ultravue (small, medium, large), MSA Ultra-twin (small, medium, large), Norton Series 7600 (one size only). Statistical analysis and review of the test data from Phases I and II indicated little, if any, variation with and without the MAG-1s with most protection factors greater than 10,000. Test data also indicated little, if any, difference in the cylinder life with and without the MAG-1s, except the Scott Presur-Pak II SCBA used with the Scottoramic facepiece. Statistical analysis of the quantitative fit test data indicated no difference in PFs for the negative-pressure devices for the Ultravue negative-pressure respirator, but a significance at the 0.05 and 0.01 levels for the Ultra-twin and Norton full facepieces, respectively.

  9. A Holographic Fractional Topological Insulator

    E-Print Network [OSTI]

    Carlos Hoyos-Badajoz; Kristan Jensen; Andreas Karch

    2010-07-19T23:59:59.000Z

    We give a holographic realization of the recently proposed low energy effective action describing a fractional topological insulator. In particular we verify that the surface of this hypothetical material supports a fractional quantum Hall current corresponding to half that of a Laughlin state.

  10. RF-Plasma Source Commissioning in Indian Negative Ion Facility

    SciTech Connect (OSTI)

    Singh, M. J.; Bandyopadhyay, M.; Yadava, Ratnakar; Chakraborty, A. K. [ITER- India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujrat (India); Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J. [Institute for Plasma Research, Bhat Gandhinagar, Gujrat (India); Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2011-09-26T23:59:59.000Z

    The Indian program of the RF based negative ion source has started off with the commissioning of ROBIN, the inductively coupled RF based negative ion source facility under establishment at Institute for Plasma research (IPR), India. The facility is being developed under a technology transfer agreement with IPP Garching. It consists of a single RF driver based beam source (BATMAN replica) coupled to a 100 kW, 1 MHz RF generator with a self excited oscillator, through a matching network, for plasma production and ion extraction and acceleration. The delivery of the RF generator and the RF plasma source without the accelerator, has enabled initiation of plasma production experiments. The recent experimental campaign has established the matching circuit parameters that result in plasma production with density in the range of 0.5-1x10{sup 18}/m{sup 3}, at operational gas pressures ranging between 0.4-1 Pa. Various configurations of the matching network have been experimented upon to obtain a stable operation of the set up for RF powers ranging between 25-85 kW and pulse lengths ranging between 4-20 s. It has been observed that the range of the parameters of the matching circuit, over which the frequency of the power supply is stable, is narrow and further experiments with increased number of turns in the coil are in the pipeline to see if the range can be widened. In this paper, the description of the experimental system and the commissioning data related to the optimisation of the various parameters of the matching network, to obtain stable plasma of required density, are presented and discussed.

  11. Variational Approach for Fractional Partial Differential Equations

    E-Print Network [OSTI]

    Guo-cheng Wu

    2010-06-25T23:59:59.000Z

    Fractional variational approach has gained much attention in recent years. There are famous fractional derivatives such as Caputo derivative, Riesz derivative and Riemann-Liouville derivative. Several versions of fractional variational principles are proposed. However, it becomes difficult to apply the existing fractional variational theories to fractional differential models, due to the definitions of fractional variational derivatives which not only contain the left fractional derivatives but also appear right ones. In this paper, a new definition of fractional variational derivative is introduced by using a modified Riemann-Liouville derivative and the fractional Euler-Lagrange principle is established for fractional partial differential equations.

  12. High Power RF Test Facility at the SNS

    SciTech Connect (OSTI)

    Y.W. Kang; D.E. Anderson; I.E. Campisi; M. Champion; M.T. Crofford; R.E. Fuja; P.A. Gurd; S. Hasan; K.-U. Kasemir; M.P. McCarthy; D. Stout; J.Y. Tang; A.V. Vassioutchenko; M. Wezensky; G.K. Davis; M. A. Drury; T. Powers; M. Stirbet

    2005-05-16T23:59:59.000Z

    RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavities have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducting and superconducting accelerating cavities and components.

  13. RF Power Upgrade for CEBAF at Jefferson Laboratory

    SciTech Connect (OSTI)

    Andrew Kimber,Richard Nelson

    2011-03-01T23:59:59.000Z

    Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

  14. 805 MHz and 201 MHz RF cavity development for MUCOOL

    SciTech Connect (OSTI)

    DLi@lbl.gov

    2002-10-10T23:59:59.000Z

    A muon cooling channel calls for very high acceleratinggradient RF structures to restore the energy lost by muons in theabsorbers. The RF structures have to be operated in a strong magneticfield and thus the use of superconducting RF cavities is excluded. Toachieve a high shunt impedance while maintaining a large enough apertureto accommodate a large transverse emittance muon beam, the cavity designadopted is a pillbox-like geometry with thin Be foils to terminate theelectromagnetic field at the cavity iris. The possibility of using gridsof thin-walled metallic tubes for the termination is also being explored.Many of the RF-related issues for muon cooling channels are being studiedboth theoretically and experimentally using an 805 MHz cavity that has apillbox-like geometry with thin Be windows to terminate the cavityaperture. The design and performance of this cavity are reported here.High-power RF tests of the 805 MHz cavity are in progress at Lab G inFermilab. The cavity has exceeded its design gradient of 30 MV/m,reaching 34 MV/m without external magnetic field. No surface damage wasobserved at this gradient. The cavity is currently under conditioning atLab G with an external magnetic field of 2.5 T. We also present here a201 MHz cavity design for muoncooling channels. The proposed cavitydesign is also suitable for use in a proof-of-principle Muon IonizationCooling Experiment (MICE).

  15. RF Pulse compression stabilization at the CTF3 CLIC test facility

    E-Print Network [OSTI]

    Dubrovskiy, Alexey

    2010-01-01T23:59:59.000Z

    In the CTF3 accelerator, the RF produced by each of ten 3 GHz klystrons goes through waveguides, RF pulse compressors and splitters. The RF phase and power transformation of these devices depend on their temperature. The quantitative effect of the room temperature variation on the RF was measured. It is the major source of undesired changes during the CTF3 operation. An RF phaseloop and a compressor temperature stabilization are developed to suppress the phase fluctuation and the power profile change due to the temperature variation. The implementation is transparent for operators, it does not limit anyhow the flexibility of RF manipulations. Expected and measured suppression characteristics will be given.

  16. Feed forward rf control system of the accelerator test facility

    SciTech Connect (OSTI)

    Ben-Zvi, I.; Xie, Jialin; Zhang, Renshan.

    1991-01-01T23:59:59.000Z

    We report a scheme to control the amplitude and phase of the rf accelerating field in a klystron driven electron linac. The amplitude and phase distribution within the rf pulse can be controlled to follow specified functions to reduce the energy spread of the electron beam being accelerated. The scheme employs fast beam energy and phase detectors and voltage-controlled electronic attenuator and phase shifter in the amplifier chain. The control voltages of these devices are generated by arbitrary function generators. The function generators' outputs are calculated numerically using an algorithm which takes into consideration the desired target function and the deviation (due to load variations or system parameter drift) from the target function. Results of preliminary tests on producing flat rf power and phase pulses from a high power klystron indicate that amplitude variation of {plus minus}0.2% and phase variation of {plus minus}1{degree} can be readily achieved. 4 refs., 3 figs.

  17. HOM Coupler Optimisation for the Superconducting RF Cavities in ESS

    E-Print Network [OSTI]

    Ainsworth, R; Calaga, R

    2012-01-01T23:59:59.000Z

    The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a ?nal energy of 2.5 GeV, with an average design beam power of 5 MW, for collision with a target used to produce a high neutron ?ux. A section of the linac will contain Superconducting RF (SCRF) cavities designed at 704 MHz. Beam induced HOMs in these cavities may drive the beam unstable and increase the cryogenic load, therefore HOM couplers are installed to provide suf?cient damping. Previous studies have shown that these couplers are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

  18. Theory and Practice of Cavity RF Test Systems

    SciTech Connect (OSTI)

    Tom Powers

    2006-08-28T23:59:59.000Z

    Over the years Jefferson Lab staff members have performed about 2500 cold cavity tests on about 500 different superconducting cavities. Most of these cavities were later installed in 73 different cryomodules, which were used in three different accelerators. All of the cavities were tested in our vertical test area. About 25% of the cryomodules were tested in our cryomodule test facility and later commissioned in an accelerator. The remainder of the cryomodules were tested and commissioned after they were installed in their respective accelerator. This paper is an overview which should provide a practical background in the RF systems used to test the cavities as well as provide the mathematics necessary to convert the raw pulsed or continuous wave RF signals into useful information such as gradient, quality factor, RF-heat loads and loaded Q?s. Additionally, I will provide the equations necessary for determining the measurement error associated with these values.

  19. A computer program for HVDC converter station RF noise calculations

    SciTech Connect (OSTI)

    Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

    1994-04-01T23:59:59.000Z

    HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

  20. Fractions: conceptual and didactic aspects

    E-Print Network [OSTI]

    Spagnolo, Filippo

    Fractions: conceptual and didactic aspects Martha Isabel Fandiño Pinilla NRD Department of transforming "Knowledge" into "knowledge to teach" is called didactic transposition and constitutes a moment

  1. Microfluidic Devices for Blood Fractionation

    E-Print Network [OSTI]

    Hou, Han Wei

    Blood, a complex biological fluid, comprises 45% cellular components suspended in protein rich plasma. These different hematologic components perform distinct functions in vivo and thus the ability to efficiently fractionate ...

  2. Listing Unique Fractional Factorial Designs

    E-Print Network [OSTI]

    Shrivastava, Abhishek Kumar

    2011-02-22T23:59:59.000Z

    LISTING UNIQUE FRACTIONAL FACTORIAL DESIGNS A Dissertation by ABHISHEK KUMAR SHRIVASTAVA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December... 2009 Major Subject: Industrial Engineering LISTING UNIQUE FRACTIONAL FACTORIAL DESIGNS A Dissertation by ABHISHEK KUMAR SHRIVASTAVA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...

  3. Recent Progress of RF Cavity Study at Mucool Test Area

    E-Print Network [OSTI]

    Yonehara, Katsuya

    2012-01-01T23:59:59.000Z

    In order to develop an RF cavity that is applicable for a muon beam cooling channel, a new facility, called Mucool Test Area (MTA) has been built at Fermilab. MTA is a unique facility whose purpose is to test RF cavities in various conditions. There are 201 and 805 MHz high power sources, a 4-Tesla solenoid magnet, a cryogenic system including a Helium liquifier, an explosion proof apparatus to operate gaseous/liquid Hydrogen, and a beam transport line to send an intense H- beam from the Fermilab Linac accelerator to the MTA hall. Recent activities at MTA will be discussed in this document.

  4. The MuCool Test Area and RF Program

    SciTech Connect (OSTI)

    Torun, Y.; Huang, D.; /IIT, Chicago; Norem, J.; /Argonne; Palmer, Robert B.; Stratakis, Diktys; /Brookhaven; Bross, A.; Chung, M.; Jansson, A.; Moretti, A.; Yonehara, K.; /Fermilab; Li, D.; /LBL, Berkeley /Jefferson Lab

    2010-05-01T23:59:59.000Z

    The MuCool RF Program focuses on the study of normal conducting RF structures operating in high magnetic field for applications in muon ionization cooling for Neutrino Factories and Muon Colliders. Here we give an overview of the program, which includes a description of the test facility and its capabilities, the current test program, and the status of a cavity that can be rotated in the magnetic field, which allows for a detailed study of the maximum stable operating gradient vs. magnetic field strength and angle.

  5. The MuCool Test Area and RF Program

    SciTech Connect (OSTI)

    Bross, A D; Jansson, A; Moretti, A; Yonehara, K; Huang, D; Torun, Y; Li, D; Norem, J; Palmer, R B; Stratakis, D

    2010-05-01T23:59:59.000Z

    The MuCool RF Program focuses on the study of normal conducting RF structures operating in high magnetic field for applications in muon ionization cooling for Neutrino Factories and Muon Colliders. This paper will give an overview of the program, which will include a description of the test facility and its capabilities, the current test program, and the status of a cavity that can be rotated in the magnetic field which allows for a more detailed study of the maximum stable operating gradient vs. magnetic field strength and angle.

  6. The Los Alamos VXI-based modular RF control system

    SciTech Connect (OSTI)

    Jachim, S.P.; Ziomek, C.; Natter, E.F.; Regan, A.H.; Hill, J.; Eaton, L.; Gutscher, W.D.; Curtin, M.; Denney, P.; Hansberry, E.; Brooks, T.

    1993-01-01T23:59:59.000Z

    This paper describes the design and implementation of the Los Alamos modular RF control system, which provides high-performance feedback and/or feedforward control of RF accelerator cavities. This is a flexible, modular control system which has been realized in the industry-standard VXI cardmodular format. A wide spectrum of system functionality can be accommodated simply by incorporating only those modules and features required for a particular application. The fundamental principles of the design approach are discussed. Details of the VXI implementation are given, including the system architecture and interfaces, performance capabilities, and available features.

  7. The Los Alamos VXI-based modular RF control system

    SciTech Connect (OSTI)

    Jachim, S.P.; Ziomek, C.; Natter, E.F.; Regan, A.H.; Hill, J.; Eaton, L.; Gutscher, W.D.; Curtin, M.; Denney, P.; Hansberry, E.; Brooks, T.

    1993-06-01T23:59:59.000Z

    This paper describes the design and implementation of the Los Alamos modular RF control system, which provides high-performance feedback and/or feedforward control of RF accelerator cavities. This is a flexible, modular control system which has been realized in the industry-standard VXI cardmodular format. A wide spectrum of system functionality can be accommodated simply by incorporating only those modules and features required for a particular application. The fundamental principles of the design approach are discussed. Details of the VXI implementation are given, including the system architecture and interfaces, performance capabilities, and available features.

  8. The Role of Alternative Respiration Pathways and the Effect of Nutrient Loading on Peat Decomposition in Plum

    E-Print Network [OSTI]

    Vallino, Joseph J.

    1 The Role of Alternative Respiration Pathways and the Effect of Nutrient Loading on Peat by stimulating soil metabolism and increasing translocation of belowground resources to aboveground plant biomass

  9. Soil respiration and microbial biomass in a savanna parkland landscape: spatio-temporal variation and environmental controls

    E-Print Network [OSTI]

    McCulley, Rebecca Lynne

    1998-01-01T23:59:59.000Z

    ) in this region. The objective of this study was to quantify variation in soil respiration, soil microbial biomass (SMB), and potential C and N mineralization rates in relation to landscape heterogeneity and woody plant encroachment in this region. In addition...

  10. Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes

    E-Print Network [OSTI]

    Martin, Timothy

    , waxes) and respiration fluxes in southeastern U.S. pine forests Behzad Mortazavi,1,2,3 Maureen H. ConteCSC), and waxes (dCW)) and respiratory carbon (foliage (dCFR), soil (dCSR) and ecosystem 13 CO2 (dCER)) for two-alkanoic acid wax molecular cluster was twice that observed for dCOM and the predominant C22­26 compound cluster

  11. Comparison of electromagnetic, thermal and mechanical calculations with rf test results in rf-dipole deflecting/crabbing cavities

    SciTech Connect (OSTI)

    Park, HyeKyoung [JLAB, ODU; De Silva, Subashini U. [ODU; Delayen, Jean R. [ODU, JLAB

    2013-12-01T23:59:59.000Z

    The current requirements of higher gradients and strict dimensional constraints in the emerging applications have required the designing of compact deflecting and crabbing rf structures. The superconducting rf-dipole cavity is one of the first novel compact designs with attractive properties such as higher gradients, higher shunt impedance and widely separated higher order modes. The recent tests performed on proof-of-principle designs of the rf-dipole geometry at 4.2 K and 2.0 K in the vertical test area at Jefferson Lab have proven the designs to achieve higher gradients with higher intrinsic quality factors and easily processed multipacting conditions. The cavity characteristics, such as pressure sensitivity and Lorentz force detuning, were studied using ANSYS before the fabrication. These characteristics were measured during the cavity test. The comparison between the simulation and the measurement provides insight how the simulation can be used for design and fabrication of future cavities.

  12. The effect of respiration heat of sorghum grain on the design of conditioned-air storage systems

    E-Print Network [OSTI]

    Haile, Danel Gene

    1967-01-01T23:59:59.000Z

    THE EFFECT OF RESPIRATION HEAT OF SORGHUM GRAIN ON THE DESIGN OF CONDITIONED-AIR STORAGE SYSTEMS A Thesis by DANEL GENE HAILE Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE January 1967 Major Subject: Agricultural Engineering THE EFFECT OF RESPIRATION HEAT OF SORGHUM GRAIN ON THE DESIGN OF CONDITIONED-AIR STORAGE SYSTEMS A Thesis by DANEL GENE HAILE Approved as to style and content by: C airman...

  13. Effects of drinking water temperature on water consumption, respiration rates, and body temperatures of lactating Holstein cows in summer 

    E-Print Network [OSTI]

    Lanham, Jeffrey Kent

    1985-01-01T23:59:59.000Z

    EFFECTS OF DRINKING WATER TEMPERATURE ON WATER CONSUMPTION, RESPIRATION RATES, AND BODY TEMPERATURES OF LACTATING HOLSTEIN COWS IN SUMMER A Thesis by JEFFREY KENT LANHAM Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1985 Major Subject: Nutrition EFFECTS OF DRINKING WATER TEMPERATURE ON WATER CONSUMPTION, RESPIRATION RATES, AND BODY TEMPERATURES OF LACTATING HOLSTEIN COWS IN SUMMER A Thesis...

  14. Dynamics of Longitudinal Phase-Space Modulations in an rf Compressor for Electron Beams

    E-Print Network [OSTI]

    Venturini, M.

    2010-01-01T23:59:59.000Z

    gain along the rf compressor for perturbation wavelengths (drift followed by a 3 m rf compressor. The beam injected atat the exit of the compressor over a range of perturbation

  15. Advances in Filter Miniaturization and Design/Analysis of RF MEMS Tunable Filters

    E-Print Network [OSTI]

    Sekar, Vikram

    2012-10-19T23:59:59.000Z

    The main purpose of this dissertation was to address key issues in the design and analysis of RF/microwave filters for wireless applications. Since RF/microwave filters are one of the bulkiest parts of communication systems, their miniaturization...

  16. MEDIUM POWER 352 MHZ SOLID STATE PULSED RF AMPLIFIERS FOR THE CERN LINAC4 PROJECT

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MEDIUM POWER 352 MHZ SOLID STATE PULSED RF AMPLIFIERS FOR THE CERN LINAC4 PROJECT J. Broere, J in the CERN Linac4. The amplifiers are water-cooled and can provide up to 33 kW pulsed RF Power, 1.5 ms pulse RF Power for the debuncher cavity. The concept is based on 1.2 kW RF power modules using the latest 6

  17. RF power potential of 45 nm CMOS technology

    E-Print Network [OSTI]

    Putnam, Christopher

    This paper presents the first measurements of the RF power performance of 45 nm CMOS devices with varying device widths and layouts. We find that 45 nm CMOS can deliver a peak output power density of around 140 mW/mm with ...

  18. RF gas plasma source development for heavy ion fusion

    SciTech Connect (OSTI)

    Ahle, L.E.; Hall, R.P.; Molvik, A.W.

    2002-02-22T23:59:59.000Z

    Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx}100 ns) for the extracted beam pulse must also be achieved. Progress on these experiments will be presented.

  19. RF Gas Plasma Source Development for Heavy Ion Fusion

    SciTech Connect (OSTI)

    Ahle, L; Hall, R P; Molvik, A W; Kwan, J W; Leung, K N

    2001-09-04T23:59:59.000Z

    Presently the Heavy Ion Fusion Virtual National Laboratory is researching ion sources and injector concepts to understand how to optimize beam brightness over a range of currents (50-2000 mA argon equivalent). One concept initially accelerates millimeter size, milliamp beamlets to 1 MeV before merging them into centimeter size, ampere beams. Computer simulations have shown the final brightness of the merged beams is dominated by the emittance growth of the merging process, as long as the beamlets ion temperature is below a few eV. Thus, a RF multicusp source capable of high current density can produce beams with better brightness compared to ones extracted from a colder source with a large aperture and lower current density. As such, experiments have begun to develop a RF multicusp source capable of delivering one amp of extracted beam current. It is expected that it will require 10 kW of 13 MHz RF power delivered via a quartz shielded, one and half turn, four inch diameter antenna. Important considerations in the development of the source include the dependence of current density and beam ion temperature on consumed RF power and gas pressure. A fast rise time ({approx} 100 ns) for the extracted beam pulse must also be achieved. Progress on these experiments will be presented.

  20. PUBLISHED VERSION RF contact development for the ITER ICRH antenna

    E-Print Network [OSTI]

    Cyclotron (IC) antenna design, ITER Organization requested qualification tests on sliding Radio contacts in relevant conditions (2.25kA @ 62.5MHz, vacuum pressure detailed with RF power tests for long shot duration (1000s) under vacuum and extensive sliding tests

  1. Superfluid helium cryogenic systems for superconducting RF cavities at KEK

    SciTech Connect (OSTI)

    Nakai, H.; Hara, K.; Honma, T.; Hosoyama, K.; Kojima, Y.; Nakanishi, K. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0033 (Japan); Kanekiyo, T. [Hitachi Plant Technologies, Ltd., Toshima-ku, Tokyo 170-8466 (Japan); Morita, S. [Hitachi Plant Mechanics Co., Ltd., Kudamatsu, Yamaguchi 744-0061 (Japan)

    2014-01-29T23:59:59.000Z

    Recent accelerator projects at KEK, such as the Superconducting RF Test Facility (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium, which can generate high gradient acceleration field. Since the operation temperature of these cavities is selected to be 2 K, we have developed two 2 K superfluid helium cryogenic systems for stable operation of superconducting RF cavities for each of STF and cERL. These two 2 K superfluid helium cryogenic systems are identical in principle. Since the operation mode of the cavities is different for STF and cERL, i.e. the pulse mode for STF and the continuous wave mode for cERL, the heat loads from the cavities are quite different. The 2 K superfluid helium cryogenic systems mainly consists of ordinary helium liquefiers/refrigerators, 2 K refrigerator cold boxes, helium gas pumping systems and high-performance transfer lines. The 2 K refrigerators and the high-performance transfer lines are designed by KEK. Some superconducting RF cavity cryomodules have been already connected to the 2 K superfluid helium cryogenic systems for STF and cERL respectively, and cooled down to 2 K successfully.

  2. Surface Superconductivity in Niobium for Superconducting RF Cavities0

    E-Print Network [OSTI]

    Surface Superconductivity in Niobium for Superconducting RF Cavities0 S. Casalbuoni1,2 , E) parameters of the ultrapure niobium used for the fabrication of the nine-cell 1.3 GHz cavities for the lin.3 GHz nine-cell cavities which are made from pure niobium and cooled by superfluid helium at 2 K. The 0

  3. Photonic RF oscillator based on monolithic DFB lasers with

    E-Print Network [OSTI]

    Boyer, Edmond

    Photonic RF oscillator based on monolithic DFB lasers with frequency-shifted feedback L. Wang, M by using monolithic dual-wavelength DFB semiconductor lasers submitted to a frequency-shifted optical. Dashed line: Lorentzian fit. (a) Free running, RBW: 30 kHz, span: 50 MHz. (b) With feedback, RBW: 1Hz

  4. rf testbed for thermoacoustic tomography D. Fallon,1

    E-Print Network [OSTI]

    Hanson, George

    rf testbed for thermoacoustic tomography D. Fallon,1 L. Yan,2 G. W. Hanson,3 and S. K. Patch4,a 1 Received 28 October 2008; accepted 22 April 2009; published online 9 June 2009 Thermoacoustic signal is a preferred acoustic coupling medium for thermoacoustics because acoustic and electromagnetic waves propagate

  5. Novel Reactor Relevant RF Actuator Schemes for the Lower

    E-Print Network [OSTI]

    location for RF launchers · Transport in tokamak sends heat and particles to low field side SOL: ­ Forces reactor is challenging: ­ Survivability is a major issue because of the harsh environment high heat solution that both mitigates PMI / coupling problems and improves core wave physics issues. #12;Reactor

  6. Dual Stewart Platform Mobility Simulator R.F. Boian1

    E-Print Network [OSTI]

    New Jersey, University of Medicine and Dentistry of

    Dual Stewart Platform Mobility Simulator R.F. Boian1 , M. Bouzit1 , G.C. Burdea1,* , and J. The system uses two Stewart platform robots to render the walking surface geometry and condition. The hardware components of the platforms and the considerations behind their design are presented here

  7. Suppressed Superconductivity on the Surface of Superconducting RF Quality Niobium for

    E-Print Network [OSTI]

    Suppressed Superconductivity on the Surface of Superconducting RF Quality Niobium for Particle 32310, USA Abstract. Significant performance degradation of superconducting RF (radio frequency) niobium superconductivity at chemically treated RF-quality niobium. We found that pinning of vortices along GBs is weaker

  8. Identification of Residual Stress State in an RF-MEMS Device

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    of wafer level tests. The membrane is part of an RF MEMS Switch man- ufactured by Raytheon Systems Co) and 3D numerical simulations. THE RAYTHEON'S RF MEMS SWITCH The RF MEMS switch technology developed by Raytheon Systems Co. provides advantageous characteristics for communication circuits by virtue of its

  9. Robust and Optimum Fractional Factorial Designs

    E-Print Network [OSTI]

    Huang, fu ze

    2010-01-01T23:59:59.000Z

    4 Robustness of Factorial Designs Summary . . . . . .10 Optimum Fractional Factorial Designs for m = 4 10.0Comparison of fractional factorial designs D 2.1 and D

  10. Robust and Optimum Fractional Factorial Designs

    E-Print Network [OSTI]

    Huang, fu ze

    2010-01-01T23:59:59.000Z

    1961a), The 2 k?p fractional factorial designs, Part I,1961b), The 2 k?p fractional factorial designs, Part II,

  11. Continued development of modeling tools and theory for RF heating

    SciTech Connect (OSTI)

    NONE

    1998-12-01T23:59:59.000Z

    Mission Research Corporation (MRC) is pleased to present the Department of Energy (DOE) with its renewal proposal to the Continued Development of Modeling Tools and Theory for RF Heating program. The objective of the program is to continue and extend the earlier work done by the proposed principal investigator in the field of modeling (Radio Frequency) RF heating experiments in the large tokamak fusion experiments, particularly the Tokamak Fusion Test Reactor (TFTR) device located at Princeton Plasma Physics Laboratory (PPPL). An integral part of this work is the investigation and, in some cases, resolution of theoretical issues which pertain to accurate modeling. MRC is nearing the successful completion of the specified tasks of the Continued Development of Modeling Tools and Theory for RF Heating project. The following tasks are either completed or nearing completion. (1) Anisotropic temperature and rotation upgrades; (2) Modeling for relativistic ECRH; (3) Further documentation of SHOOT and SPRUCE. As a result of the progress achieved under this project, MRC has been urged to continue this effort. Specifically, during the performance of this project two topics were identified by PPPL personnel as new applications of the existing RF modeling tools. These two topics concern (a) future fast-wave current drive experiments on the large tokamaks including TFTR and (c) the interpretation of existing and future RF probe data from TFTR. To address each of these topics requires some modification or enhancement of the existing modeling tools, and the first topic requires resolution of certain theoretical issues to produce self-consistent results. This work falls within the scope of the original project and is more suited to the project`s renewal than to the initiation of a new project.

  12. The RF power system for the SNS linac

    SciTech Connect (OSTI)

    Tallerico, P.J.; Reass, W.A.

    1998-12-31T23:59:59.000Z

    The initial goal of the SNS project is to produce a 1 MW average beam of protons with short pulse lengths onto a neutron-producing target. The objective of the SNS RF system is to generate 117 MW peak of pulsed 805 MHz microwave power with an accelerated beam pulse length of 1.04 ms at a 60 Hz repetition rate. The power system must be upgradeable in peak power to deliver 2 MW average power to the neutron target. The RF system also requires about 3 MW peak of RF power at 402.5 MHz, but that system is not discussed here. The design challenge is to produce an RF system at minimum cost, that is very reliable and economical to operate. The combination of long pulses and high repetition rates make conventional solutions, such as the pulse transformer and transmission line method, very expensive. The klystron, with a modulating anode, and 1.5 MW of peak output power is the baseline RF amplifier, an 56 are required in the baseline design. The authors discuss four power system configurations that are the candidates for the design. The baseline design is a floating-deck modulating anode system. A second power system being investigated is the fast-pulsed power supply, that can be turned on and off with a rise time of under 0.1 ms. This could eliminate the need for a modulator, and drastically reduce the energy storage requirements. A third idea is to use a pulse transformer with a series IGBT switch and a bouncer circuit on the primary side, as was done for the TESLA modulator. A fourth method is to use a series IGBT switch at high voltage, and not use a pulse transformer. The authors discuss the advantages and problems of these four types of power systems, but they emphasize the first two.

  13. Comparative Analysis of Carbon Plasma in Arc and RF Reactors

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z. ['Vinca' Institute of Nuclear Sciences, P.O.B. 522, 11001 Belgrade (Serbia and Montenegro); Mohai, I.; Szepvolgyi, J. [Research Laboratory of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences H-1525 Budapest, POB 17 (Hungary)

    2004-12-01T23:59:59.000Z

    Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

  14. Validation of protection provided by one brand of filtering facepiece respirator

    SciTech Connect (OSTI)

    Peacock, J.R. [Univ. of Alabama, Birmingham, AL (United States). Dept. of Environmental Health Sciences

    1995-05-01T23:59:59.000Z

    A previous laboratory study of a widely used disposable dust / mist (D/M) respirator (3M{trademark}8710) utilized a challenge agent that had high penetration values for D/M filter media. Therefore, measured protection factors (PFs) reflected both filter and faceseal penetration, and would be lower than that expected for faceseal penetration only. The purpose of this study was to determine a PF for this brand of disposable D/M respirator using a challenge agent that has low filter penetration for this type of filter. Methodology involved qualitatively (QLFT) and quantitatively (QNFT) fit testing 15 males and 15 females while wearing the respirator. One QLFT was done per subject using the saccharin method. Three QNFTs were performed on each subject utilizing a 2.5 {mu}m mass median aerodynamic diameter (MMAD) monodisperse challenge aerosol. Measured PF`s were corrected for lung deposition of this size aerosol. The average fit for each subject was the arithmetic mean of the three PFs. The PFs were found to be approximately log-normally distributed, so logs of PFs were used in the statistical analysis. The exponent of the 95% lower tolerance level (LTL) of the fifth percentile of the log PFs was 50. This compares to an exponent of the 95% LTL of the fifth percentile of the log PFs of two determined in a previous study and to the American National Standards Institute (ANSI) Assigned Protection Factor (APF) of ten. No significant difference of average fit between males and females was found. The sensitivity of the saccharin QLFT was 42.9%, and specificity could not be evaluated.

  15. Influence of temperature on respiration of excised tissues from citrus seedlings

    E-Print Network [OSTI]

    Peynado, Ascension

    1970-01-01T23:59:59.000Z

    ) To observe the change in respiration as the tissue was freeze-injured, dry flasks were loaded with 96 leaf disks per flask and placed in -26 C freezer for intervals of 5 to 30 minutes. After the freezing tests, the flasks were prepared for normal C02..., Washington, D. C. Some plants will withstand more cold than others, as evidenced by their distribution (3, 13, 50, 53). Frost resistance studies have revealed that although plants cannot tolerate intercellular ice formation? some plants will tolerate...

  16. Induction heating of FeCo nanoparticles for rapid rf curing of epoxy K. J. Miller,1,a

    E-Print Network [OSTI]

    McHenry, Michael E.

    , and cracking of the polymer. An alternative curing process involves remote, noncontact rf heating of MNP loadedInduction heating of FeCo nanoparticles for rapid rf curing of epoxy composites K. J. Miller,1,a K epoxy composites through radio-frequency rf heating. The rf response of functionalized FeCo MNPs

  17. RF Power Degradation of GaN High Electron Mobility Transistors Jungwoo Joh and Jess A. del Alamo

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    RF Power Degradation of GaN High Electron Mobility Transistors Jungwoo Joh and Jesús A. del Alamo Transistors. Our technique utilizes RF and DC figures of merit to diagnose the degradation of RF stressed and to introduce new degradation modes. At high power level, RF stress induces a prominent trapping

  18. RF telemetry makes complex surveys quick, cost-effective

    SciTech Connect (OSTI)

    Rigdon, H.K. [Nemaha Resources, Inc., Tulsa, OK (United States)

    1996-05-01T23:59:59.000Z

    Field seismic crews can gather full-range or wide-azimuth seismic datasets for 3-D surveys at costs competitive with 2-D seismic acquisition through the use of Radio Frequency (RF) telemetry acquisition systems. By eliminating need for data cables, RF telemetry systems, such as the Opseis Eagle System, can record 3-D data volumes using proven 2-D recording geometries that are a natural extension of one-dimensional (split spread) design. Design advantages include: (1) uniform sampling in both X (in-line) and Y (lateral) directions; (2) excellent offset and azimuthal distribution common to each 3-D stacking bin, and (3) uniform fold across the survey area necessary for amplitude analysis.

  19. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    Shu, G; Pei, S; Xiao, O

    2015-01-01T23:59:59.000Z

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  20. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    G. Shu; F. Zhao; S. Pei; O. Xiao

    2015-05-28T23:59:59.000Z

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  1. Free electron laser using Rf coupled accelerating and decelerating structures

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1984-01-01T23:59:59.000Z

    A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

  2. Multipacting optimization of a 750 MHz rf dipole

    SciTech Connect (OSTI)

    Delayen, Jean R. [JLAB, Old Dominion University; Castillo, Alejandro [JLAB, Old Dominion University

    2014-12-01T23:59:59.000Z

    Crab crossing schemes have been proposed to re-instate luminosity degradation due to crossing angles at the interaction points in next generation colliders to avoid the use of sharp bending magnets and their resulting large synchrotron radiation generation, highly undessirable in the detector region. The rf dipole has been considered for a different set of applications in several machines, both rings and linear colliders. We present in this paper a study of the effects on the multipacting levels and location depending on geometrical variations on the design for a crabbing/deflecting application in a high current (3/0.5 A), high repetition (750 MHz) electron/proton collider, as a matter to provide a comparison point for similar applications of rf dipoles.

  3. Characterization on RF magnetron sputtered niobium pentoxide thin films

    SciTech Connect (OSTI)

    Usha, N. [Department of Physics, Alagappa University, Karaikudi - 630 004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi - 630 004 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi - 630 004 (India)

    2014-10-15T23:59:59.000Z

    Niobium pentoxide (Nb{sub 2}O{sub 5}) thin films with amorphous nature were deposited on microscopic glass substrates at 100°C by rf magnetron sputtering technique. The effect of rf power on the structural, morphological, optical, and vibrational properties of Nb{sub 2}O{sub 5} films have been investigated. Optical study shows the maximum average transmittance of about 87% and the optical energy band gap (indirect allowed) changes between 3.70 eV and 3.47 eV. AFM result indicates the smooth surface nature of the samples. Photoluminescence measurement showed the better optical quality of the deposited films. Raman spectra show the LO-TO splitting of Nb-O stretching of Nb{sub 2}O{sub 5} films.

  4. Induction barrier RF and applications in Main Injector

    SciTech Connect (OSTI)

    Chou, W.; Wildman, D.; /Fermilab; Takagi, A.; /KEK, Tsukuba

    2006-07-01T23:59:59.000Z

    Two induction barrier rf systems have been designed and fabricated at Fermilab and installed in the Main Injector. They use the nanocrystal magnetic alloy called Finemet for the cavities and high voltage fast MOSFET switches for the modulators. Each system delivers {+-}10 kV square pulses at 90 kHz. They have been used for adiabatic beam stacking (beam compression), machine acceptance measurement and gap cleaning in the injection area for magnet protection, and will be tested for fast beam stacking for doubling the proton flux on the NuMI production target. The systems work reliably and cost much less than a resistive barrier rf system. Comparison with a similar system built at KEK reveals many similarities and also some important differences. This work is partially funded by the US-Japan collaborative agreement.

  5. RF Input Power Couplers for High Current SRF Applications

    SciTech Connect (OSTI)

    Khan, V. F. [Helmholtz Zentrum Berlin, Germany; Anders, W. [Helmholtz Zentrum Berlin, Germany; Burrill, Andrew [Helmholtz Zentrum Berlin, Germany; Knobloch, Jens [Helmholtz Zentrum Berlin, Germany; Kugeler, Oliver [Helmholtz Zentrum Berlin, Germany; Neumann, Axel [Helmholtz Zentrum Berlin, Germany; Wang, Haipeng [JLAB

    2014-12-01T23:59:59.000Z

    High current SRF technology is being explored in present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input RF power required for the photo-injector as well as booster cavities where there is no energy recovery process. A high power co-axial input power coupler is being developed to be used for the photo-injector and booster cavities at the nominal beam current. The coupler is based on the KEK–cERL design and has been modified to minimise the penetration of the coupler tip in the beam pipe without compromising on beam-power coupling (Qext ~105). Herein we report on the RF design of the high power (115 kW per coupler, dual couplers per cavity) bERLinPro (BP) coupler along with initial results on thermal calculations. We summarise the RF conditioning of the TTF-III couplers (modified for cw operation) performed in the past at BESSY/HZB. A similar conditioning is envisaged in the near future for the low current SRF photo-injector and the bERLinPro main linac cryomodule.

  6. Is it safe to wear contact lenses with a full-facepiece respirator

    SciTech Connect (OSTI)

    Da Roza, R.A.; Weaver, C.

    1985-08-16T23:59:59.000Z

    The Federal OSHA regulation that prohibits the wearing of contact lenses while using a respirator is being challenged by users. We surveyed 9100 fire fighters around the US and Canada to determine if the wearing of contacts while using a self-contained breathing apparatus (SCBA) had caused any serious problems to warrant this strict regulation. Of the 1405 questionnaires returned, 403 fire fighters do wear contacts with SCBA, despite the regulation. Of these, only six responded that contact-lens related problems had caused them to remove the facepiece in an environment in which the facepiece would normally be worn. In contrast, the safety-related problems caused by eyeglasses in SCBA - which are legal - are proportionately higher. Over half of the supervisors returning the questionnaire admitted that some of their employees wear contacts with SCBA; however, these supervisors knew of only eight cases when contact-lens problems had caused the facepiece to be removed when it should not have been. Our investigation has indicated that these problems were not significantly hazardous. We believe that the use of contacts with a respirator should not be prohibited. 7 refs., 2 figs., 7 tabs.

  7. Spatial distribution of an uranium-respiring betaproteobacterium at the rifle, CO field research site

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

    Koribanics, Nicole M.; Tuorto, Steven J.; Lopez-Chiaffarelli, Nora; McGuinness, Lora R.; Häggblom, Max M.; Williams, Kenneth H.; Long, Philip E.; Kerkhof, Lee J.; Morais, Paula V

    2015-04-13T23:59:59.000Z

    The Department of Energy’s Integrated Field-Scale Subsurface Research Challenge Site (IFRC) at Rifle, Colorado was created to address the gaps in knowledge on the mechanisms and rates of U(VI) bioreduction in alluvial sediments. Previous studies at the Rifle IFRC have linked microbial processes to uranium immobilization during acetate amendment. Several key bacteria believed to be involved in radionuclide containment have been described; however, most of the evidence implicating uranium reduction with specific microbiota has been indirect. Here, we report on the cultivation of a microorganism from the Rifle IFRC that reduces uranium and appears to utilize it as a terminalmore »electron acceptor for respiration with acetate as electron donor. Furthermore, this bacterium constitutes a significant proportion of the subsurface sediment community prior to biostimulation based on TRFLP profiling of 16S rRNA genes. 16S rRNA gene sequence analysis indicates that the microorganism is a betaproteobacterium with a high similarity to Burkholderia fungorum. This is, to our knowledge, the first report of a betaproteobacterium capable of uranium respiration. Our results indicate that this microorganism occurs commonly in alluvial sediments located between 3-6 m below ground surface at Rifle and may play a role in the initial reduction of uranium at the site.« less

  8. Spatial distribution of an uranium-respiring betaproteobacterium at the rifle, CO field research site

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

    Koribanics, Nicole M. [Rutgers Univ., New Brunswick, NJ (United States); Tuorto, Steven J. [Rutgers Univ., New Brunswick, NJ (United States); Lopez-Chiaffarelli, Nora [Rutgers Univ., New Brunswick, NJ (United States); McGuinness, Lora R. [Rutgers Univ., New Brunswick, NJ (United States); Häggblom, Max M. [Rutgers Univ., New Brunswick, NJ (United States); Williams, Kenneth H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Long, Philip E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kerkhof, Lee J. [Rutgers Univ., New Brunswick, NJ (United States); Morais, Paula V [Univ. of Coimbra (Portugal)

    2015-04-13T23:59:59.000Z

    The Department of Energy’s Integrated Field-Scale Subsurface Research Challenge Site (IFRC) at Rifle, Colorado was created to address the gaps in knowledge on the mechanisms and rates of U(VI) bioreduction in alluvial sediments. Previous studies at the Rifle IFRC have linked microbial processes to uranium immobilization during acetate amendment. Several key bacteria believed to be involved in radionuclide containment have been described; however, most of the evidence implicating uranium reduction with specific microbiota has been indirect. Here, we report on the cultivation of a microorganism from the Rifle IFRC that reduces uranium and appears to utilize it as a terminal electron acceptor for respiration with acetate as electron donor. Furthermore, this bacterium constitutes a significant proportion of the subsurface sediment community prior to biostimulation based on TRFLP profiling of 16S rRNA genes. 16S rRNA gene sequence analysis indicates that the microorganism is a betaproteobacterium with a high similarity to Burkholderia fungorum. This is, to our knowledge, the first report of a betaproteobacterium capable of uranium respiration. Our results indicate that this microorganism occurs commonly in alluvial sediments located between 3-6 m below ground surface at Rifle and may play a role in the initial reduction of uranium at the site.

  9. Characterization of an RF-Driven Plasma Ion Source for Heavy Ion Fusion

    SciTech Connect (OSTI)

    Westenskow, G A; Hall, R P; Halaxa, E; Kwan, J W

    2003-05-13T23:59:59.000Z

    We are testing a high-current-density high-brightness Argon-Ion Source for Heavy Ion Fusion applications. The 100-kV 20-{micro}s source has produced up to 5 mA of Ar{sup +} in a single beamlet. The extraction current density is 100 mA/cm2. We have measured the emittance of the beamlet, and the fraction of Ar{sup ++} ions under several operating conditions. We present measurements of the extracted current density as a function of RF power and gas pressure ({approx} 2 mT), current density uniformity, and energy dispersion (due to charge exchange). We are testing a 80-kV 61-hole multi-beamlet array that will produce a total current > 200 mA. In the current experiments the beamlets are not merged into a single beam. A 500-kV experiment where the beamlets will be merged to a produce 0.5-A beam is being planned.

  10. Fractional topological insulators in three dimensions

    E-Print Network [OSTI]

    Joseph Maciejko; Xiao-Liang Qi; Andreas Karch; Shou-Cheng Zhang

    2010-11-14T23:59:59.000Z

    Topological insulators can be generally defined by a topological field theory with an axion angle theta of 0 or pi. In this work, we introduce the concept of fractional topological insulator defined by a fractional axion angle and show that it can be consistent with time reversal (T) invariance if ground state degeneracies are present. The fractional axion angle can be measured experimentally by the quantized fractional bulk magnetoelectric polarization P_3, and a `halved' fractional quantum Hall effect on the surface with Hall conductance of the form (p/q)(e^2/2h) with p,q odd. In the simplest of these states the electron behaves as a bound state of three fractionally charged `quarks' coupled to a deconfined non-Abelian SU(3) `color' gauge field, where the fractional charge of the quarks changes the quantization condition of P_3 and allows fractional values consistent with T-invariance.

  11. Fractional Topological Insulators in Three Dimensions

    SciTech Connect (OSTI)

    Maciejko, Joseph; Zhang Shoucheng [Department of Physics, Stanford University, Stanford, California 94305 (United States); Qi Xiaoliang [Microsoft Research, Station Q, Elings Hall, University of California, Santa Barbara, California 93106 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States); Karch, Andreas [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

    2010-12-10T23:59:59.000Z

    Topological insulators can be generally defined by a topological field theory with an axion angle {theta} of 0 or {pi}. In this work, we introduce the concept of fractional topological insulator defined by a fractional axion angle and show that it can be consistent with time reversal T invariance if ground state degeneracies are present. The fractional axion angle can be measured experimentally by the quantized fractional bulk magnetoelectric polarization P{sub 3}, and a 'halved' fractional quantum Hall effect on the surface with Hall conductance of the form {sigma}{sub H}=(p/q)(e{sup 2}/2h) with p, q odd. In the simplest of these states the electron behaves as a bound state of three fractionally charged 'quarks' coupled to a deconfined non-Abelian SU(3) 'color' gauge field, where the fractional charge of the quarks changes the quantization condition of P{sub 3} and allows fractional values consistent with T invariance.

  12. Fractional Inversion in Krylov Space

    E-Print Network [OSTI]

    B. Bunk

    1998-05-28T23:59:59.000Z

    The fractional inverse $M^{-\\gamma}$ (real $\\gamma >0$) of a matrix $M$ is expanded in a series of Gegenbauer polynomials. If the spectrum of $M$ is confined to an ellipse not including the origin, convergence is exponential, with the same rate as for Chebyshev inversion. The approximants can be improved recursively and lead to an iterative solver for $M^\\gamma x = b$ in Krylov space. In case of $\\gamma = 1/2$, the expansion is in terms of Legendre polynomials, and rigorous bounds for the truncation error are derived.

  13. Ultrananocrystalline diamond films with optimized dielectric properties for advanced RF MEMS capacitive switches

    DOE Patents [OSTI]

    Sumant, Anirudha V.; Auciello, Orlando H.; Mancini, Derrick C.

    2013-01-15T23:59:59.000Z

    An efficient deposition process is provided for fabricating reliable RF MEMS capacitive switches with multilayer ultrananocrystalline (UNCD) films for more rapid recovery, charging and discharging that is effective for more than a billion cycles of operation. Significantly, the deposition process is compatible for integration with CMOS electronics and thereby can provide monolithically integrated RF MEMS capacitive switches for use with CMOS electronic devices, such as for insertion into phase array antennas for radars and other RF communication systems.

  14. New SLED 3 system for Multi-mega Watt RF compressor

    E-Print Network [OSTI]

    Xu, Chen; Tantawi, Sami

    2014-01-01T23:59:59.000Z

    A compact X band SLED is introduced for X band RF compressing application. This SLED compressor consists two major parts: a rectangular to circular waveguide converter and an overmoded spherical cavity. The RF compressor is designed to convert 50 magawatt X band RF power with pulse length 1.5 microseconds and deliver 200 megawatts with pulse length 106 nanoseconds to the X band accelerating structure.

  15. Original article Micronutrients in biomass fractions

    E-Print Network [OSTI]

    Boyer, Edmond

    Original article Micronutrients in biomass fractions of holm oak, beech and fir forests biomass fractions in individual monospecific stands of holm oak (Quercus ilex L), beech (Fagus sylvatica L in different biomass fractions of the holm oak forest studied. This can be related to the low soil pH values

  16. What is a Weber fraction? Justin Halberda

    E-Print Network [OSTI]

    Halberda, Justin

    What is a Weber fraction? Justin Halberda Johns Hopkins University Corresponding Author: Justin System (ANS), discrimination within the ANS, and how to think about Weber fractions (w). What the ANS representations for numerosities 4-10 for an individual with Weber fraction = .125. You can think

  17. Commissioning of a higher harmonic RF system for the Advanced Light Source

    E-Print Network [OSTI]

    Byrd, John M.; De Santis, Stefano; Georgsson, Mattias; Stover, G.; Fox, John D.; Teytelman, Dmitry

    2000-01-01T23:59:59.000Z

    Commissioning of a higher harmonic RF system for theAbstract We report on the commissioning of a higher harmonicpresents the results of commissioning of the ALS harmonic

  18. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect (OSTI)

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M. [Association Euratom-Belgian State, LPP-ERM-KMS, 1000 Brussels (Belgium); Bobkov, V.; Rohde, V.; Schneider, P. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Douai, D.; Kogut, D. [Association Euratom-CEA, CEA, IRFM, 13108 St Paul lez Durance (France); Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G. [Association Euratom-IEK-4, Forschungszentrum Jülich, 52425 Jülich (Germany); Moiseenko, V. [Institute of Plasma Physics NSC KIPT, 61108 Kharkiv (Ukraine); Noterdaeme, J.-M. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching, Germany and Ghent University, 9000 Ghent (Belgium); Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12T23:59:59.000Z

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,?=?{sub H+}, and with its high cyclotron harmonics (HCH), ?=10?{sub cH+}? HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}?0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}?350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ?H} ?1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

  19. MHD simulation of RF current drive in MST

    SciTech Connect (OSTI)

    Hendries, E. R.; Anderson, J. K.; Forest, C. B.; Reusch, J. A.; Seltzman, A. H.; Sovinec, C. R. [University of Wisconsin, Madison WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States)

    2014-02-12T23:59:59.000Z

    Auxiliary heating and current drive using RF waves such as the electron Bernstein wave (EBW) promises to advance the performance of the reversed field pinch (RFP). In previous computational work [1], a hypothetical edge-localized current drive is shown to suppress the tearing activity which governs the macroscopic transport properties of the RFP. The ideal conditions for tearing stabilization include a reduced toroidal induction, and precise width and radial position of the Gaussian-shaped external current drive. In support of the EBW experiment on the Madison Symmetric Torus, an integrated modeling scheme now incorporates ray tracing and Fokker-Plank predictions of auxiliary current into single fluid MHD. Simulations at low Lundquist number (S ? 10{sup 4}) generally agree with the previous work; significantly more burdensome simulations at MST-like Lundquist number (S ? 3×10{sup 6}) show unexpected results. The effect on nonlinearly saturated current profile by a particular RF-driven external force decreases in magnitude and widens considerably as the Lundquist number increases toward experimental values. Simulations reproduce the periodic current profile relaxation events observed in experiment (sawteeth) in the absence of current profile control. Reduction of the tearing mode amplitudes is still observable; however, reduction is limited to periods between the large bursts of magnetic activity at each sawtooth. The sawtoothing pattern persists with up to 10 MW of externally applied RF power. Periods with prolonged low tearing amplitude are predicted with a combination of external current drive and a reduced toroidal loop voltage, consistent with previous conclusions. Finally, the resistivity profile is observed to have a strong effect on the optimal externally driven current profile for mode stabilization.

  20. RF heating systems evolution for the WEST project

    SciTech Connect (OSTI)

    Magne, R.; Achard, J.; Armitano, A.; Argouarch, A.; Berger-By, G.; Bernard, J. M.; Bouquey, F.; Charabot, N.; Colas, L.; Corbel, E.; Delpech, L.; Ekedahl, A.; Goniche, M.; Guilhem, D.; Hillairet, J.; Jacquot, J.; Joffrin, E.; Litaudon, X.; Lombard, G.; Mollard, P. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); and others

    2014-02-12T23:59:59.000Z

    Tore Supra is dedicated to long pulse operation at high power, with a record in injected energy of 1 GJ (2.8 MW × 380 s) and an achieved capability of 12 MW injected power delivered by 3 RF systems: Lower Hybrid Current Drive (LHCD), Ion Cyclotron Resonance Heating (ICRH) and Electron Cyclotron Resonance Heating (ECRH). The new WEST project (W [tungsten] Environment in Steady-state Tokamak) aims at fitting Tore Supra with an actively cooled tungsten coated wall and a bulk tungsten divertor. This new device will offer to ITER a test bed for validating the relevant technologies for actively cooled metallic components, with D-shaped H-mode plasmas. For WEST operation, different scenarii able to reproduce ITER relevant conditions in terms of steady state heat loads have been identified, ranging from a high RF power scenario (15 MW, 30 s) to a high fluence scenario (10 MW, 1000 s). This paper will focus on the evolution of the RF systems required for WEST. For the ICRH system, the main issues are its ELM resilience and its CW compatibility, three new actively cooled antennas are being designed, with the aim of reducing their sensitivity to the load variations induced by ELMs. The LH system has been recently upgraded with new klystrons and the PAM antenna, the possible reshaping of the antenna mouths is presently studied for matching with the magnetic field line in the WEST configuration. For the ECRH system, the device for the poloidal movement of the mirrors of the antenna is being changed for higher accuracy and speed.

  1. A brief history of high power RF proton linear accelerators

    SciTech Connect (OSTI)

    Browne, J.C.

    1996-12-31T23:59:59.000Z

    The first mention of linear acceleration was in a paper by G. Ising in 1924 in which he postulated the acceleration of positive ions induced by spark discharges which produced electric fields in gaps between a series of {open_quotes}drift tubes{close_quotes}. Ising apparently was not able to demonstrate his concept, most likely due to the limited state of electronic devices. Ising`s work was followed by a seminal paper by R. Wideroe in 1928 in which he demonstrated the first linear accelerator. Wideroe was able to accelerate sodium or potassium ions to 50 keV of energy using drift tubes connected alternately to high frequency waves and to ground. Nuclear physics during this period was interested in accelerating protons, deuterons, electrons and alpha particles and not heavy ions like sodium or potassium. To accelerate the light ions required much higher frequencies than available at that time. So linear accelerators were not pursued heavily at that time. Research continued during the 1930s but the development of high frequency RF tubes for radar applications in World War 2 opened the potential for RF linear accelerators after the war. The Berkeley laboratory of E. 0. Lawrence under the leadership of Luis Alvarez developed a new linear proton accelerator concept that utilized drift tubes that required a full RF period to pass through as compared to the earlier concepts. This development resulted in the historic Berkeley 32 MeV proton linear accelerator which incorporated the {open_quotes}Alvarez drift tube{close_quotes} as the basic acceleration scheme using surplus 200 MHz radar components.

  2. Aquatic respiration in many fishes is a mechanical ballet in which water is pumped from the oropharyngeal chamber,

    E-Print Network [OSTI]

    Summers, Adam P.

    pattern at the three openings into the respiratory system: (1) in through the spiracle only, (2Aquatic respiration in many fishes is a mechanical ballet in which water is pumped from of discontinuous flow into the mouth and out of the gill slit(s). The blood flow in the respiratory structures

  3. Oxygen isotope content of CO2 in nocturnal ecosystem respiration: 1. Observations in forests along a precipitation transect in Oregon,

    E-Print Network [OSTI]

    Ehleringer, Jim

    in the vapor pressure deficit of air that caused isotopic enrichment of soil and leaf water. The enriched soil to evaporative enrichment overshadowed the original isotopic composition of precipitation as a first orderOxygen isotope content of CO2 in nocturnal ecosystem respiration: 1. Observations in forests along

  4. Diurnal and seasonal variation in the carbon isotope composition of leaf dark-respired CO2 in velvet mesquite

    E-Print Network [OSTI]

    Williams, David G.

    Diurnal and seasonal variation in the carbon isotope composition of leaf dark-respired CO2 82071, USA ABSTRACT We evaluated diurnal and seasonal patterns of carbon isotope composition of leaf- ing that progressive 13 C enrichment of the CO2 evolved by darkened leaves during the daytime mainly

  5. Reduction of forest floor respiration by fertilization on both carbon dioxide-enriched and reference 17-year-old

    E-Print Network [OSTI]

    Oren, Ram

    be best applied to aggrading forest systems where soil resources have not been fully exploited (Mikan et affect the available C pool and impact microbial activity. When N amendments are added to peat soils, Canada. Amador JA, Jones RD (1993) Nutrient limitations on microbial respiration in peat soils

  6. Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool S.L. Jaccard a,d,

    E-Print Network [OSTI]

    Gilli, Adrian

    Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool S.L. Jaccard of the overturning circulation. Volumetrically the Pacific Ocean dominates the world ocean (it is three times larger of Atmospheric and Oceanic Sciences, Princeton University, Princeton, USA c Department of Geosciences, Princeton

  7. PVDF microbelts for harvesting energy from respiration Chengliang Sun, Jian Shi, Dylan J. Bayerl and Xudong Wang*

    E-Print Network [OSTI]

    Wang, Xudong

    PVDF microbelts for harvesting energy from respiration Chengliang Sun, Jian Shi, Dylan J. Bayerl the energy from low-speed air flow to electricity via their resonant oscillation. The micrometre thick PVDF microbelts were able to generate sufficient electrical energy from low speed air flow for the sustained

  8. Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct measurements of ballasting by opal and calcite

    E-Print Network [OSTI]

    Matthews, Adrian

    Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct of copepod fecal pellets egested by Temora longicornis were measured using a nanoflagellate (Rhodomonas sp pellet production varied between 0.8 pellets ind21 h21 and 3.8 pellets ind21 h21 and was significantly

  9. Short-Term Effects of Experimental Burning and Thinning on Soil Respiration in an Old-Growth,

    E-Print Network [OSTI]

    North, Malcolm

    sustainability and CO2 sequestration, we evaluated the effects of burning and thin- ning treatments on soil application of these forest management practices. Soil respiration, including autotrophic and hetero- trophic and Schlesinger 1992), forest management activities, such as burning and thinning, can also change soil environ

  10. Exploring the biochemistry at the extracellular redox frontier of bacterial mineral Fe(III) respiration

    SciTech Connect (OSTI)

    Richardson, David J.; Edwards, Marcus; White, Gaye F.; Baiden, Nanakow; Hartshorne, Robert S.; Fredrickson, Jim K.; Shi, Liang; Zachara, John M.; Gates, Andrew J.; Butt, Julea N.; Clarke, Thomas

    2012-06-01T23:59:59.000Z

    Many species of the bacterial Shewanella genus are notable for their ability to respire in anoxic environments utilizing insoluble minerals of Fe(III) and Mn(IV) as extracellular electron acceptors. In Shewanella oneidensis, the process is dependent on the decahaem electron-transport proteins that lie at the extracellular face of the outer membrane where they can contact the insoluble mineral substrates. These extracellular proteins are charged with electrons provided by an inter-membrane electron-transfer pathway that links the extracellular face of the outer membrane with the inner cytoplasmic membrane and thereby intracellular electron sources. In the present paper, we consider the common structural features of two of these outermembrane decahaem cytochromes, MtrC and MtrF, and bring this together with biochemical, spectroscopic and voltammetric data to identify common and distinct properties of these prototypical members of different clades of the outer-membrane decahaem cytochrome superfamily.

  11. Multi-Year Lags between Forest Browning and Soil Respiration at High Northern Latitudes

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin; Bunn, Andrew G.; Thomson, Allison M.

    2012-11-26T23:59:59.000Z

    High-latitude northern ecosystems are experiencing rapid climate changes, and represent a large potential climate feedback because of their high soil carbon densities and shifting disturbance regimes. A significant carbon flow from these ecosystems is soil respiration (RS, the flow of carbon dioxide, generated by plant roots and soil fauna, from the soil surface to atmosphere), and any change in the high-latitude carbon cycle might thus be reflected in RS observed in the field. This study used two variants of a machine-learning algorithm and least squares regression to examine how remotely-sensed canopy greenness (NDVI), climate, and other variables are coupled to annual RS based on 105 observations from 64 circumpolar sites in a global database. The addition of NDVI roughly doubled model performance, with the best-performing models explaining ~62% of observed RS variability

  12. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01T23:59:59.000Z

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.

  13. Doped H(2)-Filled RF Cavities for Muon Beam Cooling

    SciTech Connect (OSTI)

    Yonehara, K.; Chung, M.; Jansson, A.; Hu, M.; Moretti, A.; Popovic, M.; /Fermilab; Alsharo'a, M.; Johnson, R.P.; Neubauer, M.; Sah, R.; /Muons Inc., Batavia; Rose, D.V.; /Voss Sci., Albuquerque

    2009-05-01T23:59:59.000Z

    RF cavities pressurized with hydrogen gas may provide effective muon beam ionization cooling needed for muon colliders. Recent 805 MHz test cell studies reported below include the first use of SF{sub 6} dopant to reduce the effects of the electrons that will be produced by the ionization cooling process in hydrogen or helium. Measurements of maximum gradient in the Paschen region are compared to a simulation model for a 0.01% SF{sub 6} doping of hydrogen. The observed good agreement of the model with the measurements is a prerequisite to the investigation of other dopants.

  14. THERMAL MODELING OF ION EXCHANGE COLUMNS WITH SPHERICAL RF RESIN

    SciTech Connect (OSTI)

    Lee, S.; King, W.

    2009-12-30T23:59:59.000Z

    Models have been developed to simulate the thermal performance of RF columns fully loaded with radioactive cesium. Temperature distributions and maximum temperatures across the column were calculated during Small Column Ion Exchange (SCIX) process upset conditions with a focus on implementation at Hanford. A two-dimensional computational modeling approach was taken to include conservative, bounding estimates for key parameters such that the results will provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on RF. The current full-scale design for the SCIX system includes a central cooling tube, and one objective of these calculations was to examine its elimination to simplify the design. Results confirmed that a column design without a central cooling tube is feasible for RF, allowing for the possibility of significant design simplifications if it can be assumed that the columns are always filled with liquid. With active cooling through the four outer tubes, the maximum column diameter expected to maintain the temperature below the assumed media and safety limits is 26 inches, which is comparable to the current design diameter. Additional analysis was conducted to predict the maximum column temperatures for the previously unevaluated accident scenario involving inadvertent drainage of liquid from a cesium-saturated column, with retention of the ion exchange media and cesium in the column. As expected, much higher maximum temperatures are observed in this case due to the poor heat transfer properties of air versus liquid. For this hypothetical accident scenario involving inadvertent and complete drainage of liquid from a cesium-saturated column, the modeling results indicate that the maximum temperature within a 28 inch diameter RF column with external cooling is expected to exceed 250 C within 2 days, while the maximum temperature of a 12 inch column is maintained below 100 C. In addition, the calculation results demonstrate that the cooling tube system external to an air-filled column is not highly effective at reducing the maximum temperature, but the baseline design using a central cooling tube inside the column provides sufficient cooling to maintain the maximum temperature near the assumed safety limit.

  15. Surface Characterization of the LCLS RF Gun Cathode

    SciTech Connect (OSTI)

    Brachmann, Axel; /SLAC; Decker, Franz-Josef; /SLAC; Ding, Yuantao; /SLAC; Dowell, David; /SLAC; Emma, Paul; /SLAC; Frisch, Josef; /SLAC; Gilevich, Sasha; /SLAC; Hays, Gregory; /SLAC; Hering, Philippe; /SLAC; Huang, Zhirong; /SLAC; Iverson, Richard; /SLAC; Loos, Henrik; /SLAC; Miahnahri, Alan; /SLAC; Nordlund, Dennis; /SLAC; Nuhn, Heinz-Dieter; /SLAC; Pianetta, Piero; /SLAC; Turner, James; /SLAC; Welch, James; /SLAC; White, William; /SLAC; Wu, Juhao; /SLAC; Xiang, Dao; /SLAC

    2012-06-25T23:59:59.000Z

    The first copper cathode installed in the LCLS RF gun was used during LCLS commissioning for more than a year. However, after high charge operation (> 500 pC), the cathode showed a decline of quantum efficiency within the area of drive laser illumination. They report results of SEM, XPS and XAS studies that were carried out on this cathode after it was removed from the gun. X-ray absorption and X-ray photoelectron spectroscopy reveal surface contamination by various hydrocarbon compounds. In addition they report on the performance of the second installed cathode with emphasis on the spatial distribution of electron emission.

  16. The modeling of RF stacking of protons in the Accumulator

    SciTech Connect (OSTI)

    Yoon, Phil S.; /Fermilab /Rochester U.; McGinnis, David P.; Chou, Weiren; /Fermilab

    2005-06-01T23:59:59.000Z

    When the Run2 collider program is terminated in 2009, the present pbar source will be available for other usages. One possible application is to convert the Antiproton Accumulator to a proton accumulator so that the beam power from the Main Injector could be greatly enhanced [1]. The Accumulator has the unique feature of very large momentum acceptance. It is possible to stack 3-4 Booster batches in the longitudinal phase space before transferring them to the Main Injector or Recycler. This note shows the simulation of RF stacking using the code ESME [2].

  17. RF Characterization of Niobium Films for Superconducting Cavities

    E-Print Network [OSTI]

    Aull† , S; Doebert, S; Junginger, T; Ehiasarian, AP; Knobloch, J; Terenziani, G

    2013-01-01T23:59:59.000Z

    The surface resistance RS of superconductors shows a complex dependence on the external parameters such as temperature, frequency or radio-frequency (RF) field. The Quadrupole Resonator modes of 400, 800 and 1200 MHz allow measurements at actual operating frequencies of superconducting cavities. Niobium films on copper substrates have several advantages over bulk niobium cavities. HIPIMS (High-power impulse magnetron sputtering) is a promising technique to increase the quality and therefore the performance of niobium films. This contribution will introduce CERNs recently developed HIPIMS coating apparatus. Moreover, first results of niobium coated copper samples will be presented, revealing the dominant loss mechanisms.

  18. Superconducting DC and RF Properties of Ingot Niobium

    E-Print Network [OSTI]

    Dhakal, Pashupati; Kneisel, Peter; Myneni, Ganapati Rao

    2012-01-01T23:59:59.000Z

    The thermal conductivity, DC magnetization and penetration depth of large-grain niobium hollow cylindrical rods fabricated from ingots, manufactured by CBMM subjected to chemical and heat treatment were measured. The results confirm the influence of chemical and heat-treatment processes on the superconducting properties, with no significant dependence on the impurity concentrations in the original ingots. Furthermore, RF properties, such as the surface resistance and quench field of the niobium rods were measured using a TE011 cavity. The hollow niobium rod is the center conductor of this cavity, converting it to a coaxial cavity. The quench field is limited by the critical heat flux through the rods' cooling channel.

  19. Fabrication Processes for the PEP II RF Cavities

    SciTech Connect (OSTI)

    Franks, R.Mark; /LLNL, Livermore; Rimmer, Robert A.; /LBL, Berkeley; Schwarz, Heinz; /SLAC

    2011-09-01T23:59:59.000Z

    This paper presents the major steps used in the fabrication of the 26 RF Cavities required for the PEP-II B-factory. Several unique applications of conventional processes have been developed and successfully implemented: electron beam welding (EBW), with minimal porosity, of .75 inch (19 mm) copper cross-sections; extensive 5-axis milling of water channels; electroplating of .37 inch (10 mm) thick OFE copper; tuning of the cavity by profiling beam noses prior to final joining with the cavity body; and machining of the cavity interior, are described here.

  20. Measurement of current distribution on RF coils using MR imaging

    E-Print Network [OSTI]

    Wu, Yu

    1993-01-01T23:59:59.000Z

    in Appendix A show the structure of these two coils. Coil 1 in Figure A. l is a simple square loop, and coil 3 in Figure A. 3 is a square loop with an inside square conductor which is designed to show the eddy current distribution induced by the outside RF...Hs that the eddy current induced on the inside square conductor is mainly distributed on the edges, but the current distribution on the outside loop is not significantly affected by the eddy current by comparing Figure 2. 4 with Figure 2. 2. Figure 2. 3 and 2. 5...

  1. Index of /research/alcator/facility/Procedures/RF

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn Other News CommunityPortal8mse-solidedgeLH [ICO]RF [ICO]

  2. Microsoft PowerPoint - rf_5year_review

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA / USACE SWPA / SPRAresults from phasedKenneth7, 2007RF

  3. Assessment of contrast enhanced respiration managed cone-beam CT for image guided radiotherapy of intrahepatic tumors

    SciTech Connect (OSTI)

    Jensen, Nikolaj K. G., E-mail: nkyj@regionsjaelland.dk [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada)] [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Stewart, Errol [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada) [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada); Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7 (Canada); Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 (Canada); Lock, Michael; Fisher, Barbara [Radiation Oncology, London Regional Cancer Program, London, Ontario N6A3K7 (Canada) [Radiation Oncology, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Kozak, Roman [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada)] [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada); Chen, Jeff [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada) [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Lee, Ting-Yim [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada) [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada); Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7 (Canada); Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Wong, Eugene [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada) [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2014-05-15T23:59:59.000Z

    Purpose: Contrast enhancement and respiration management are widely used during image acquisition for radiotherapy treatment planning of liver tumors along with respiration management at the treatment unit. However, neither respiration management nor intravenous contrast is commonly used during cone-beam CT (CBCT) image acquisition for alignment prior to radiotherapy. In this study, the authors investigate the potential gains of injecting an iodinated contrast agent in combination with respiration management during CBCT acquisition for liver tumor radiotherapy. Methods: Five rabbits with implanted liver tumors were subjected to CBCT with and without motion management and contrast injection. The acquired CBCT images were registered to the planning CT to determine alignment accuracy and dosimetric impact. The authors developed a simulation tool for simulating contrast-enhanced CBCT images from dynamic contrast enhanced CT imaging (DCE-CT) to determine optimal contrast injection protocols. The tool was validated against contrast-enhanced CBCT of the rabbit subjects and was used for five human patients diagnosed with hepatocellular carcinoma. Results: In the rabbit experiment, when neither motion management nor contrast was used, tumor centroid misalignment between planning image and CBCT was 9.2 mm. This was reduced to 2.8?mm when both techniques were employed. Tumors were not visualized in clinical CBCT images of human subjects. Simulated contrast-enhanced CBCT was found to improve tumor contrast in all subjects. Different patients were found to require different contrast injections to maximize tumor contrast. Conclusions: Based on the authors’ animal study, respiration managed contrast enhanced CBCT improves IGRT significantly. Contrast enhanced CBCT benefits from patient specific tracer kinetics determined from DCE-CT.

  4. Responses of soil respiration to elevated CO2, air warming, and changing soil water availability in an old-field grassland

    SciTech Connect (OSTI)

    Wan, Shiqiang [Chinese Academy of Sciences; Norby, Richard J [ORNL; Childs, Joanne [ORNL; Weltzin, Jake [University of Tennessee, Knoxville (UTK)

    2007-01-01T23:59:59.000Z

    Responses of soil respiration to atmospheric and climatic change will have profound impacts on ecosystem and global C cycling in the future. This study was conducted to examine effects on soil respiration of the concurrent driving factors of elevated atmospheric CO2 concentration, rising temperature, and changing precipitation in a constructed old-field grassland in eastern Tennessee, USA. Model ecosystems of seven old-field species in 12 open-top chambers (4 m in diameter) were treated with two CO2 (ambient and ambient plus 300 ppm) and two temperature (ambient and ambient plus 3 C) levels. Two split plots with each chamber were assigned with high and low soil moisture levels. During the 19-month experimental period from June 2003 to December 2004, higher CO2 concentration and soil water availability significantly increased mean soil respiration by 35.8% and 15.7%, respectively. The effects of air warming on soil respiration varied seasonally from small reductions to significant increases to no response, and there was no significant main effect. In the wet side of elevated CO2 chambers, air warming consistently caused increases in soil respiration, whereas in other three combinations of CO2 and water treatments, warming tended to decrease soil respiration over the growing season but increase it over the winter. There were no interactive effects on soil respiration among any two or three treatment factors irrespective of testing time period. Temperature sensitivity of soil respiration was reduced by air warming, lower in the wet than the dry side, and not affected by CO2 treatment. Variations of soil respiration responses with soil temperature and soil moisture ranges could be primarily attributable to the seasonal dynamics of plant growth and its responses to the three treatments. Using a conceptual model to interpret the significant relationships of treatment-induced changes in soil respiration with changes in soil temperature and moisture observed in this study, we conclude that elevated CO2, air warming, and changing soil water availability had both direct and indirect effects on soil respiration via changes in the three controlling factors: soil temperature, soil moisture, and C substrate. Our results demonstrate that the response of soil respiration to climatic warming should not be represented in models as a simple temperature response function. A more mechanistic understanding of the direct and indirect impacts of concurrent global change drivers on soil respiration is needed to facilitate the interpretation and projection of ecosystem and global C cycling in response to atmospheric and climate change.

  5. DC and RF Measurements of Serial Bi-SQUID Arrays

    E-Print Network [OSTI]

    Prokopenko, G V; de Escobar, A Leese; Taylor, B; de Andrade, M C; Berggren, S; Longhini, P; Palacios, A; Nisenoff, M; Fagaly, R L

    2012-01-01T23:59:59.000Z

    SQUID arrays are promising candidates for low profile antennas and low noise amplifier applications. We present the integrated circuit designs and results of DC and RF measurements of the wideband serial arrays based on integration of linear bi-SQUID cells forming a Superconducting Quantum Interference Filter (bi-SQUID SQIF). Various configurations of serial arrays designs are described. The measured linearity, power gain, and noise temperature are analyzed and compared. The experimental results are matched to results of mathematical modeling. A serial bi-SQUID SQIF arrays are mounted into a coplanar waveguide (CPW) and symmetrically grounded to corresponding sides of CPW. The RF output comes out from the central common line, which is also used for DC biasing and forms a symmetrical balanced output. The signal and DC flux biasing line is designed as coplanar lines passed in parallel over each bi-SQUID cell in a bidirectional fashion concentrating magnetic flux inside of each cell. Serial bi-SQUID SQIF arrays ...

  6. System studies of rf current drive for MST

    SciTech Connect (OSTI)

    Anderson, J. K.; Burke, D. R.; Forest, C. B.; Goetz, J. A.; Hendries, E. R.; Seltzman, A. H.; Thomas, M. A. [Department of Physics, University of Wisconsin, Madison, WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States); Kaufman, M. C. [Department of Physics, University of Wisconsin, Madison, WI (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2011-12-23T23:59:59.000Z

    Two rf schemes are being studied on the MST reversed field pinch for their potential in current profile control experiments. MHD modeling has shown that a substantial externally-driven off axis parallel current can improve stability of the dominant core tearing modes. A radially localized axisymmetric population of fast electrons has been observed by SXR emission during LH injection (100kW at 800MHz), and is consistent with CQL3D modeling which predicts a small driven current. Computational work suggests that doubling the input power will statistically improve the LH-induced SXR signal to background ratio, and that about 2MW of injected power (an order of magnitude increase) will drive enough current for stabilization of tearing modes. Additionally, a 1 MW 5.5 GHz electron Bernstein wave (EBW) experiment is under construction, which utilizes a very simple and compact antenna compatible with the demands of the RFP. EBW allows access to electron cyclotron heating and current drive in the overdense plasma. Coupling of the external electromagnetic wave to the EBW has been demonstrated, and initial tests at {approx}100kW power have produced a small, localized xray flux consistent with rf heating and high diffusivity of fast electrons. Computational work is currently underway to answer the very important questions of how much power is required, and what level of electron diffusivity is tolerable, to generate a consequential amount of EBW current.

  7. Quarter-Fraction Factorial Designs Constructed via Quaternary Codes

    E-Print Network [OSTI]

    Phoa, Frederick; Xu, H Q

    2008-01-01T23:59:59.000Z

    Theory QUARTER-FRACTION FACTORIAL DESIGNS and Applications.for fractional factorial designs and pro- jection justi?regular fractional factorial designs. Ann. Statist. 27 1914–

  8. A Catalogue of Three-Level Fractional Factorial Designs

    E-Print Network [OSTI]

    Xu, Hongquan

    2004-01-01T23:59:59.000Z

    on 2 n?k fractional factorial designs and search for minimumLevel Fractional Factorial Designs Hongquan Xu Department ofchoice of fractional factorial designs. Minimum aberration

  9. A Catalogue of Three-Level Fractional Factorial Designs

    E-Print Network [OSTI]

    Hongquan Xu

    2011-01-01T23:59:59.000Z

    on 2 n?k fractional factorial designs and search for minimumLevel Fractional Factorial Designs Hongquan Xu Department ofchoice of fractional factorial designs. Minimum aberration

  10. Quarter-Fraction Factorial Designs Constructed via Quaternary Codes

    E-Print Network [OSTI]

    Frederick Phoa; Hongquan Xu

    2011-01-01T23:59:59.000Z

    Theory QUARTER-FRACTION FACTORIAL DESIGNS and Applications.for fractional factorial designs and pro- jection justi?regular fractional factorial designs. Ann. Statist. 27 1914–

  11. Moment Aberration Projection for Nonregular Fractional Factorial Designs

    E-Print Network [OSTI]

    Xu, Hongquan; Deng, Lih-Yuan

    2002-01-01T23:59:59.000Z

    The 2 k?p Fractional Factorial Designs,” Technometrics, Box,Three-Level Fractional Factorial Designs With Small Runs,”of Fractional Factorial Designs,” Journal of Complexity, 17,

  12. Projection, Search, and Optimality in Fractional Factorial Experiments

    E-Print Network [OSTI]

    Zheng, Zongpeng

    2014-01-01T23:59:59.000Z

    regular fractional factorial designs and their applications.variance fractional factorial designs and their optimalityoptimal 2 m fractional factorial designs of Resolution V, m

  13. Summary report, California Department of Forestry and Fire Protection evaluation of full-face air-purifying respirators for wildland fire fighting use

    SciTech Connect (OSTI)

    Beason, D.G.; Johnson, J.S.; Foote, K.L. [Lawrence Livermore National Lab., CA (United States); Weaver, W.A. [California Dept. of Forestry and Fire Protection, Sacramento, CA (United States)

    1996-02-01T23:59:59.000Z

    Wildland fire suppression personnel employed by the CDF do not currently have the equipment to protect themselves from the short-term acute affects of smoke from wildland fires. In addition, no regulations exist that specify appropriate respiratory protection and the current air-purifying respirator technology and carbon monoxide monitoring has not been adapted to fit wildland fire suppression requirements. This three-year limited study evaluated the ability of wildland fire fighters to perform their normal job function while wearing full-face air-purifying respirators. In the first two years of this study we designed, developed and field tested a prototype ``smart`` air-purifying respirator which incorporated a real-time carbon monoxide monitor into a commercial full-face respirator.` Data on carbon monoxide exposure while fighting wildland fires was collected. During the third year of this study we evaluated eight different commercially available full-face air-purifying respirators equipped with a variety of cartridges. Apparatus to aid the fire fighter in carrying the respirator and carbon monoxide personal monitor was designed and fabricated. A smoke exposure test method was developed and a laboratory study on the penetration of smoke through respirator cartridges was conducted.

  14. Characterization of a high temperature superconducting oxide thin-film RF SQUID

    SciTech Connect (OSTI)

    Daly, K.P.; Silver, A.H.; Simon, R.W.; Platt, C.E.; Lee, A.E.; Wire, M.S.; Zimmerman, J.E.

    1989-03-01T23:59:59.000Z

    The authors have successfully fabricated and operated RF SQUIDS made from thin-films of the high temperature superconducting oxide ErBa/sub 2/Cu/sub 3/O/sub 7-x/. The ideal triangular quantum interference pattern characteristic of RF SQUIDS is observed. The performance of a particular device, operating between 60 and 65K, is described in detail.

  15. Green radio despite "Dirty RF" front-end Myriam Ariaudo*1

    E-Print Network [OSTI]

    Fijalkow, Inbar

    Green radio despite "Dirty RF" front-end Myriam Ariaudo*1 , Inbar Fijalkow1 , Jean-Luc Gautier1 in order to contribute in a Green radio development. In fact, the effects of typical RF imperfections, like algorithms are applied. Such algorithms enable Green applications (e.g., Orthogonal Frequency Division

  16. Porkolab@DPP-LA-2001 Waves and RF Heating in Plasmas

    E-Print Network [OSTI]

    (interface with technology) #12;Porkolab@DPP-LA-2001 RF Heating in Plasmas-circa 1950s The "Primitive" DaysPorkolab@DPP-LA-2001 Waves and RF Heating in Plasmas: a Historical Perspective Miklos Porkolab MIT wave propagation physics · 1980's: ICRF heating works at the multi-MW level! LH Current Drive

  17. Study of high pressure gas filled RF cavities for muon collider

    E-Print Network [OSTI]

    Yonehara, Katsuya

    2015-01-01T23:59:59.000Z

    Muon collider is a considerable candidate of the next-generation high-energy lepton collider machine. Operating an RF cavity in a multi-Tesla magnet is a critical requirement in a muon accelerator and a cooling channel. However, the maximum RF gradient in a vacuum RF cavity is strongly limited by an external magnetic field. Dense hydrogen gas filled RF cavity has been proposed since it is functional of generating a high RF accelerating gradient in a strong magnetic field and making an ionization cooling process at the same time. A critical issue of the cavity is a beam- induced plasma that consumes a considerable amount of RF power. The gas filled RF test cell was made and measured the RF loading due to a beam-induced plasma by using an intense proton beam at Fermilab. By doping an electronegative gas in dense hydrogen, the plasma loading effect is significantly mitigated. The result shows that the cavity is functional with a muon collider beam. Recent progress is shown in this presentation.

  18. SYNTHESIS OF ZINC FERRITE NANOPOWDERS IN AN RF THERMAL PLASMA , J. Szpvlgyi1

    E-Print Network [OSTI]

    Gubicza, Jenõ

    SYNTHESIS OF ZINC FERRITE NANOPOWDERS IN AN RF THERMAL PLASMA I. Mohai1 , J. Szépvölgyi1 , J University, P.O.B. 32, Budapest, H-1518, Hungary Abstract Nanosized zinc ferrite spinel powders of various. Ferrites synthetized in the RF plasma reactor were compared to that produced by the conventional ceramic

  19. Study of lithium diffusion in RF sputtered Nickel/Vanadium mixed oxides thin films

    E-Print Network [OSTI]

    Artuso, Florinda

    Study of lithium diffusion in RF sputtered NickelÁ/Vanadium mixed oxides thin films F. Artuso a lithium insertion inside RF sputtered Ni/V mixed oxides thin films have been investigated employing, showed three steps clearly involved in the intercalation mechanism of lithium in the oxide films: (i

  20. WORLD RECORD ACCELERATING GRADIENT ACHIEVED IN A SUPERCONDUCTING NIOBIUM RF CAVITY

    E-Print Network [OSTI]

    Geng, Rong-Li

    WORLD RECORD ACCELERATING GRADIENT ACHIEVED IN A SUPERCONDUCTING NIOBIUM RF CAVITY R.L. Geng On November 16, 2004, a CW accelerating gradient of 46 MV/m was achieved in a superconducting niobium cav- ity/m was achieved. This represents a world record gradient in a niobium RF resonator. At a reduced temperature of 1

  1. MIRCO-STRUCTURES OF RF SURFACES IN THE ELECTRON-BEAM-WELD REGIONS OF NIOBIUM

    E-Print Network [OSTI]

    Geng, Rong-Li

    MIRCO-STRUCTURES OF RF SURFACES IN THE ELECTRON-BEAM-WELD REGIONS OF NIOBIUM R.L. Gengyz , J-structures of RF surfaces in the electron-beam-weld (EBW) regions of niobium samples were studied. These surfaces.These observations have important impli- cations in explanations of the high-field-Q-drop of niobium superconducting

  2. Power Reduction of CMP Communication Networks via RF-Interconnects M-C. Frank Chang

    E-Print Network [OSTI]

    Cong, Jason "Jingsheng"

    latency and low energy consumption [5][7]. RF-I transmission lines provide single-cycle crossPower Reduction of CMP Communication Networks via RF-Interconnects M-C. Frank Chang , Jason Cong}@cs.ucla.edu Electrical Engineering Department, UCLA. {mfchang, socher, roccotam}@ee.ucla.edu Abstract As chip

  3. An All Metal High Power Circularly Polarized 100 MW RF Load

    SciTech Connect (OSTI)

    Fowkes, W.R.; Jongewaard, E.N.; Loewen, R.J.; Tantawi, S.G.; Vlieks, A.E.; /SLAC

    2011-08-30T23:59:59.000Z

    A compact RF load has been designed using a cascaded array of lossy radial RF chokes to dissipate 100 MW peak and 8 kW average power uniformly along the length of the load. Operation in the circularly polarized Te{_}11 mode assures uniform dissipation azimuthally as well.

  4. RF propagation in an HVAC duct system: impulse response characteristics of the channel

    E-Print Network [OSTI]

    Stancil, Daniel D.

    RF propagation in an HVAC duct system: impulse response characteristics of the channel Pavel V, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow at RF and microwave frequencies of com- mon interest. HVAC ducts can be used as a wireless communication

  5. Automatic generation of RF compact models from device simulation S. Luryi and A. Pacelli

    E-Print Network [OSTI]

    Luryi, Serge

    , parasitic elements, and complex physical effects such as self- heating and hot-carrier transport. Keywords: Compact models; device simulation; RF; inter- connects; self-heating 1 INTRODUCTION Conventional RF of Electrical and Computer Engineering State University of New York, Stony Brook, NY 11794-2350, (serge

  6. Dependence of nuclear spin singlet lifetimes on RF spin-locking power

    E-Print Network [OSTI]

    Stephen J. DeVience; Ronald L. Walsworth; Matthew S. Rosen

    2012-01-06T23:59:59.000Z

    We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.

  7. Nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging

    DOE Patents [OSTI]

    Fukushima, Eiichi (Los Alamos, NM); Roeder, Stephen B. W. (La Mesa, CA); Assink, Roger A. (Albuquerque, NM); Gibson, Atholl A. V. (Bryan, TX)

    1986-01-01T23:59:59.000Z

    An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio-frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

  8. Catalytic cracking of residual petroleum fractions

    SciTech Connect (OSTI)

    Moore, H.F.; Mayo, S.L.; Goolsby, T.L. (Research and Development Dept., Ashland Petroleum Co., Ashland, KY (US))

    1991-01-01T23:59:59.000Z

    This paper reports on Arabian Light crude oil vacuum bottoms fractionated into five high-boiling fractions by wiped film evaporation, and the fractions subjected to catalytic cracking in a fixed-fluidized bed using a commercial equilibrium cracking catalyst. Density, aromaticity, and heteroatom content generally increased with boiling point, as did metals content except for vanadium and iron which demonstrated possible bimodal distributions. The cracking response of these fractions showed increasing yields of dry gas and coke, with decreasing gasoline yields, as a function of increasing apparent boiling point as would normally be expected. Surprisingly, however, local maxima were observed for wet gas yield and total conversion, with local minima for cycle oil and slurry yields, in the region of the 1200-1263{degrees}F (650-680{degrees}C) middle fraction. All fractions showed significant response to cracking, with coke yields generally being the only negative factor observed.

  9. Review of Some Promising Fractional Physical Models

    E-Print Network [OSTI]

    Vasily E. Tarasov

    2015-02-14T23:59:59.000Z

    Fractional dynamics is a field of study in physics and mechanics investigating the behavior of objects and systems that are characterized by power-law non-locality, power-law long-term memory or fractal properties by using integrations and differentiation of non-integer orders, i.e., by methods of the fractional calculus. This paper is a review of physical models that look very promising for future development of fractional dynamics. We suggest a short introduction to fractional calculus as a theory of integration and differentiation of non-integer order. Some applications of integro-differentiations of fractional orders in physics are discussed. Models of discrete systems with memory, lattice with long-range inter-particle interaction, dynamics of fractal media are presented. Quantum analogs of fractional derivatives and model of open nano-system systems with memory are also discussed.

  10. Stable Isotope Fractionations in Biogeochemical Reactive Transport

    E-Print Network [OSTI]

    Druhan, Jennifer Lea

    2012-01-01T23:59:59.000Z

    34 S fractionation . Summary A mesoscale study of isotopicion exchange and ! 44 Ca . A mesoscale study of isotopicmodeling and ! 34 S . A mesoscale study of isotopic

  11. Respiration Induced Heart Motion and Indications of Gated Delivery for Left-Sided Breast Irradiation

    SciTech Connect (OSTI)

    Qi, X. Sharon, E-mail: xiangrong.qi@ucdenver.edu [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Hu, Angela [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Wang Kai [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Newman, Francis [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Crosby, Marcus; Hu Bin; White, Julia; Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2012-04-01T23:59:59.000Z

    Purpose: To investigate respiration-induced heart motion for left-sided breast irradiation using a four-dimensional computed tomography (4DCT) technique and to determine novel indications to assess heart motion and identify breast patients who may benefit from a gated treatment. Methods and Materials: Images of 4DCT acquired during free breathing for 20 left-sided breast cancer patients, who underwent whole breast irradiation with or without regional nodal irradiation, were analyzed retrospectively. Dose distributions were reconstructed in the phases of 0%, 20%, and 50%. The intrafractional heart displacement was measured in three selected transverse CT slices using D{sub LAD} (the distance from left ascending aorta to a fixed line [connecting middle point of sternum and the body] drawn on each slice) and maximum heart depth (MHD, the distance of the forefront of the heart to the line). Linear regression analysis was used to correlate these indices with mean heart dose and heart dose volume at different breathing phases. Results: Respiration-induced heart displacement resulted in observable variations in dose delivered to the heart. During a normal free-breathing cycle, heart-induced motion D{sub LAD} and MHD changed up to 9 and 11 mm respectively, resulting in up to 38% and 39% increases of mean doses and V{sub 25.2} for the heart. MHD and D{sub LAD} were positively correlated with mean heart dose and heart dose volume. Respiratory-adapted gated treatment may better spare heart and ipsilateral-lung compared with the conventional non-gated plan in a subset of patients with large D{sub LAD} or MHD variations. Conclusion: Proposed indices offer novel assessment of heart displacement based on 4DCT images. MHD and D{sub LAD} can be used independently or jointly as selection criteria for respiratory gating procedure before treatment planning. Patients with great intrafractional MHD variations or tumor(s) close to the diaphragm may particularly benefit from the gated treatment.

  12. rf power system for thrust measurements of a helicon plasma source Alexander W. Kieckhafer and Mitchell L. R. Walker

    E-Print Network [OSTI]

    Walker, Mitchell

    rf power system for thrust measurements of a helicon plasma source Alexander W. Kieckhafer measurement stand and showed that rf power has no statistically significant contribution to the thrust stand now, a true thrust diagnostic that can measure thrust of a rf device does not exist. A helicon plasma

  13. TESLA-FEL Report 2005-06 DIGITAL LOW LEVEL RF CONTROL SYSTEM FOR THE DESY TTF

    E-Print Network [OSTI]

    TESLA-FEL Report 2005-06 DIGITAL LOW LEVEL RF CONTROL SYSTEM FOR THE DESY TTF VUV-FEL LINAC Valeri Electron Laser (VUV-FEL) Linac each klystron supplies RF power to up to 32 cavities. The superconducting. The VUV-FEL Linac RF control system employs a completely digital feedback system to provide flexibility

  14. A new microphonics measurement method for superconducting RF cavities

    SciTech Connect (OSTI)

    Gao,Zheng; He,Yuan; Chang,Wei; Powers, Tom [JLAB; Yue,Wei-ming; Zhu,Zheng-long; Chen,Qi

    2014-09-01T23:59:59.000Z

    Mechanical vibrations of the superconducting cavity, also known as microphonics, cause shifts in the resonant frequency of the cavity. In addition to requiring additional RF power, these frequency shifts can contribute to errors in the closed loop phase and amplitude regulation. In order to better understand these effects, a new microphonics measurement method was developed, and the method was successfully used to measure microphonics on the half-wave superconducting cavity when it was operated in a production style cryostat. The test cryostat held a single ?=0.1 half-wave cavity which was operated at 162.5 MHz [1] and [2]. It's the first time that the National Instruments PXIe-5641R intermediate frequency transceiver has been used for microphonics measurements in superconducting cavities. The new microphonics measurement method and results will be shown and analyzed in this paper.

  15. Superconducting DC and RF Properties of Ingot Niobium

    SciTech Connect (OSTI)

    Pashupati Dhakal, Gianluigi Ciovati, Peter Kneisel, Ganapati Rao Myneni

    2011-07-01T23:59:59.000Z

    The thermal conductivity, DC magnetization and penetration depth of large-grain niobium hollow cylindrical rods fabricated from ingots, manufactured by CBMM subjected to chemical and heat treatment were measured. The results confirm the influence of chemical and heat-treatment processes on the superconducting properties, with no significant dependence on the impurity concentrations in the original ingots. Furthermore, RF properties, such as the surface resistance and quench field of the niobium rods were measured using a TE{sub 011} cavity. The hollow niobium rod is the center conductor of this cavity, converting it to a coaxial cavity. The quench field is limited by the critical heat flux through the rods' cooling channel.

  16. Results of a preliminary, high power RF thruster test

    SciTech Connect (OSTI)

    Brewer, L.; Karras, T.; Frind, G.; Holmes, D.G.

    1989-01-01T23:59:59.000Z

    The objective of this program was to demonstrate a high power electrodeless, RF electric propulsion concept. This was successfully accomplished. No attempt was made to optimize the design of the thruster with regard to physical dimensions, mass flow, nozzle shape, operational frequency, or power level. Measurements made were chamber pressure, total and static pressures at the nozzle exit plane and exhaust tank pressure. Mass flows range from about 0.4 to 1 gm/sec and, assuming perfect gas relationships, specific impulses up to 580 sec were obtained. Typical chamber pressure was 300 torr exhausting to a tank pressure of about 10 torr. Working fluids used were argon, helium and mixtures of the two. No degration of the device was detected after 12 start/stop cycles, about three hours of total run time, and a maximum input power of 70 kW. 10 refs.

  17. Nanometer emittance ultralow charge beams from rf photoinjectors

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

    Li, R. K.; Roberts, K. G.; Scoby, C. M.; To, H.; Musumeci, P.

    2012-09-01T23:59:59.000Z

    In this paper we discuss the generation of a new class of high brightness relativistic electron beams, characterized by ultralow charge (0.1–1 pC) and ultralow normalized emittance (<50??nm ). These beams are created in rf photoinjectors when the laser is focused on the cathode to very small transverse sizes (<30???m rms). In this regime, the charge density at the cathode approaches the limit set by the extraction electric field. By shaping the laser pulse to have a cigarlike aspect ratio (the longitudinal dimension much larger than the transverse dimension) and a parabolic temporal profile, the resulting space charge dominated dynamics creates a uniformly filled ellipsoidal distribution and the emittance can be nearly preserved to its thermal value. We also present a new method, based on a variation of the pepper-pot technique, for single shot measurements of the ultralow emittances for this new class of beams.

  18. National RF Test Facility as a multipurpose development tool

    SciTech Connect (OSTI)

    McManamy, T.J.; Becraft, W.R.; Berry, L.A.; Blue, C.W.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Loring, C.M. Jr.; Moeller, F.A.; Ponte, N.S.

    1983-01-01T23:59:59.000Z

    Additions and modifications to the National RF Test Facility design have been made that (1) focus its use for technology development for future large systems in the ion cyclotron range of frequencies (ICRF), (2) expand its applicability to technology development in the electron cyclotron range of frequencies (ECRF) at 60 GHz, (3) provide a facility for ELMO Bumpy Torus (EBT) 60-GHz ring physics studies, and (4) permit engineering studies of steady-state plasma systems, including superconducting magnet performance, vacuum vessel heat flux removal, and microwave protection. The facility will continue to function as a test bed for generic technology developments for ICRF and the lower hybrid range of frequencies (LHRF). The upgraded facility is also suitable for mirror halo physics experiments.

  19. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    SciTech Connect (OSTI)

    Poole, B R; Harris, J R

    2011-03-07T23:59:59.000Z

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  20. RF Design Optimization for New Injector Cryounit at CEBAF

    SciTech Connect (OSTI)

    Wang, Haipeng; Cheng, Guangfeng; Hannon, Fay E.; Hofler, Alicia S.; Kazimi, Reza; Preble, Joe; Rimmer, Robert A.

    2013-06-01T23:59:59.000Z

    A new injector superconducting RF (SRF) cryounit with one new 2-cell, B=0.6 cavity plus one refurbished 7-cell, B=0.97, C100 style cavity has been re-designed and optimized for the engineering compatibility of existing module for CEBAF operation. The optimization of 2-cell cavity shape for longitudinal beam dynamic of acceleration from 200keV to 533keV and the minimization of transverse kick due to the waveguide couplers to less than 1 mrad have been considered. Operating at 1497MHz, two cavities has been designed into a same footprint of CEBAF original quarter cryomodule to deliver an injection beam energy of 5MeV in less than 0.27{degree} rms bunch length and a maximum energy spread of 5keV.

  1. Kinetics of plasma electrons in static and rf fields

    SciTech Connect (OSTI)

    Ivanov, Y.A.; Lebedev, Y.A.; Polak, L.S.

    1980-01-01T23:59:59.000Z

    The effect of the frequency of the field producing a plasma on the isotropic part of the electron energy distribution is analyzed. Analytic solutions of the Boltzmann equation are derived for high-energy tail of the electron energy distribution for static and rf fields. The results show that the shape of the tail of the distribution can be effectively controlled by changing the ratio of the field frequency to the effective frequency with which electrons collide with heavy particles and by choosing the appropriate dependence of the cross section for elastic scattering of electrons by heavy particles on the electron energy (by appropriate choice of the gas from which the plasma is formed). These results agree with experimental results in the literature.

  2. Material Selection and Characterization for High Gradient RF Applications

    E-Print Network [OSTI]

    Arnau-Izquierdo, G; Heikkinen, S; Ramsvik, T; Sgobba, Stefano; Taborelli, M; Wuensch, W

    2007-01-01T23:59:59.000Z

    The selection of candidate materials for the accelerating cavities of the Compact Linear Collider (CLIC) is carried out in parallel with high power RF testing. The maximum DC breakdown field of copper, copper alloys, refractory metals, aluminium and titanium have been measured with a dedicated setup. Higher maximum fields are obtained for refractory metals and for titanium, which exhibits, however, important damages after conditioning. Fatigue behaviour of copper alloys has been studied for surface and bulk by pulsed laser irradiation and ultrasonic excitation, respectively. The selected copper alloys show consistently higher fatigue resistance than copper in both experiments. In order to obtain the best local properties in the device a possible solution is a bi-metallic assembly. Junctions of molybdenum and copper-zirconium UNS C15000 alloy, achieved by HIP (Hot Isostatic Pressing) diffusion bonding or explosion bonding were evaluated for their mechanical strength. The reliability of the results obtained wit...

  3. The Development of the Linac Coherent Light Source RF Gun

    E-Print Network [OSTI]

    Dowell, David H; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling

    2015-01-01T23:59:59.000Z

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL). In addition to many other stringent requirements, the LCLS XFEL requires extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. This paper describes the analysis and design improvements of the BNL/SLAC/UCLA s-band gun leading to achievement of the LCLS performance goals.

  4. Remote sensing of heart rate and patterns of respiration on a stationary subject using 94 GHz millimeter wave interferometry.

    SciTech Connect (OSTI)

    Mikhelson, I. V.; Bakhtiari, S.; Elmer, T. W.; Sahakian, A. V. (Nuclear Engineering Division); (Northwestern University)

    2011-06-01T23:59:59.000Z

    Using continuous wave, 94-GHz millimeter-wave interferometry, a signal representing chest wall motion can be obtained that contains both the heart rate and respiration patterns of a human subject. These components have to be separated from each other in the received signal. Our method was to use the quadrature and in-phase components of the signal, after removing the mean of each, to find the phase, unwrap it, and convert it to a displacement measurement. Using this, the power spectrum was examined for peaks, which corresponded to the heart rate and respiration rate. The displacement waveform of the chest was also analyzed for discrete heartbeats using a novel wavelet decomposition technique.

  5. Soil respiration in perennial grass and shrub ecosystems: Linking environmental controls with plant and microbial sources on seasonal and diel timescales

    E-Print Network [OSTI]

    Carbone, Mariah S; Winston, Gregory C; Trumbore, Susan E

    2008-01-01T23:59:59.000Z

    R. Vargas (2008), Automated soil respiration measure- ments:and J. M. Wraith (2007), Diurnal hysteresis between soil CO2 and soil temperature is controlled by soil water content,

  6. An exploratory study of heart rate, respiration, and galvanic skin response as they relate to affective rating of recorded music

    E-Print Network [OSTI]

    Bruner, Gordon Carl

    1978-01-01T23:59:59.000Z

    that because of the autonomic equilibrium maintained in the body, it is impossible to stimulate a system, no matter how mildly, without some evidence of the disturbance being produced. So the question faced by the researcher was not whether the body... of autonomic reactivity (heart rate, respiration, and galvanic skin response) and the level at which a person rated a song. Further, the main product of the study is a statement oi some of the salient issues and factors involved in the testing...

  7. Macrobenthic community structure and total sediment respiration at cold hydrocarbon seeps in the northern Gulf of Mexico 

    E-Print Network [OSTI]

    Nunnally, Clifton Charles

    2004-11-15T23:59:59.000Z

    respiration should signal clear differentiation between macrobenthic communities at seeps and those away from seeps. These changes could possibly be exhibited in a gradient separating seep locales from the background benthic... pathway that metabolizes methane and other hydrocarbons results with the production of hydrogen sulfide (Boetius et al., 2000; DeLong, 2000; Hansen et al., 1998; Hoehler et al., 1994). This occurs in a coupled reaction of anaerobic methane oxidation...

  8. Fractional Power Control for Decentralized Wireless Networks

    E-Print Network [OSTI]

    Jindal, Nihar

    1 Fractional Power Control for Decentralized Wireless Networks Nihar Jindal, Steven Weber, Jeffrey G. Andrews Abstract We propose and analyze a new paradigm for power control in decentralized wireless networks, termed fractional power control. Transmission power is chosen as the current channel

  9. Void Fraction Instrument operation and maintenance manual

    SciTech Connect (OSTI)

    Borgonovi, G.; Stokes, T.I.; Pearce, K.L.; Martin, J.D.; Gimera, M.; Graves, D.B.

    1994-09-01T23:59:59.000Z

    This Operations and Maintenance Manual (O&MM) addresses riser installation, equipment and personnel hazards, operating instructions, calibration, maintenance, removal, and other pertinent information necessary to safely operate and store the Void Fraction Instrument. Final decontamination and decommissioning of the Void Fraction Instrument are not covered in this document.

  10. Combinatorial Dimension in Fractional Cartesian Products

    E-Print Network [OSTI]

    Gao, Frank

    Combinatorial Dimension in Fractional Cartesian Products Ron Blei,1 Fuchang Gao2 1 Department of Mathematics, University of Connecticut, Storrs, Connecticut 06268; e-mail: blei@math.uconn.edu 2 Department? Correspondence to: R. Blei © 2004 Wiley Periodicals, Inc. 146 #12;COMBINATORIAL DIMENSION IN FRACTIONAL CARTESIAN

  11. [Carbon isotope fractionation inplants]. Final report

    SciTech Connect (OSTI)

    O`Leary, M.H.

    1990-12-31T23:59:59.000Z

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  12. R&D activities on RF contacts for the ITER ion cyclotron resonance heating launcher

    E-Print Network [OSTI]

    Hillairet, Julien; Bamber, Rob; Beaumont, Bertrand; Bernard, Jean-Michel; Delaplanche, Jean-Marc; Durodié, Frédéric; Lamalle, Philippe; Lombard, Gilles; Nicholls, Keith; Shannon, Mark; Vulliez, Karl; Cantone, Vincent; Hatchressian, Jean-Claude; Lebourg, Philippe; Martinez, André; Mollard, Patrick; Mouyon, David; Pagano, Marco; Patterlini, Jean-Claude; Soler, Bernard; Thouvenin, Didier; Toulouse, Lionel; Verger, Jean-Marc; Vigne, Terence; Volpe, Robert

    2015-01-01T23:59:59.000Z

    Embedded RF contacts are integrated within the ITER ICRH launcher to allow assembling, sliding and to lower the thermo-mechanical stress. They have to withstand a peak RF current up to 2.5 kA at 55 MHz in steady-state conditions, in the vacuum environment of themachine.The contacts have to sustain a temperature up to 250{\\textdegree}Cduring several days in baking operations and have to be reliable during the whole life of the launcher without degradation. The RF contacts are critical components for the launcher performance and intensive R&D is therefore required, since no RF contactshave so far been qualified at these specifications. In order to test and validate the anticipated RF contacts in operational conditions, CEA has prepared a test platform consisting of a steady-state vacuum pumped RF resonator. In collaboration with ITER Organization and the CYCLE consortium (CYclotronCLuster for Europe), an R&D program has been conducted to develop RF contacts that meet the ITER ICRH launcher specification...

  13. Pressurized H_{2} rf Cavities in Ionizing Beams and Magnetic Fields

    SciTech Connect (OSTI)

    Chung, M.; et al.

    2013-10-01T23:59:59.000Z

    A major technological challenge in building a muon cooling channel is operating RF cavities in multi-tesla external magnetic fields. We report the first experimental characterization of a high pressure gas-filled 805 MHz RF cavity for use with intense ionizing beams and strong external magnetic fields. RF power consumption by beam-induced plasma was investigated with hydrogen and deuterium gases with pressures between 20 and 100 atm and peak RF gradients between 5 and 50 MV/m. The energy absorption per ion pair-RF cycle ranges from 10?18 to 10?16 J. The low pressure case agrees well with an analytical model based on electron and ion mobilities. Varying concentrations of oxygen gas were investigated to remove free electrons from the cavity and reduce the RF power consumption. Measurements of the electron attachment time to oxygen and rate of ion-ion recombination were also made. Additionally, we demonstrate the operation of the gas-filled RF cavity in a solenoidal field of up to 3 T, finding no major magnetic field dependence. These results indicate that a high pressure gas-filled cavity is potentially a viable technology for muon ionization cooling.

  14. Does an elevated CO2 concentration decrease dark respiration in trees? Final technical report

    SciTech Connect (OSTI)

    Long, Stephen [Univ. of Illinois, Urbana, IL (US)

    2003-12-31T23:59:59.000Z

    Averaged across many previous investigations, doubling the CO2 concentration ([CO2]) has frequently been reported to cause an instantaneous reduction of leaf dark respiration measured as CO2 efflux. No known mechanism accounts for this effect. While four recent studies have shown that the measurement of respiratory CO2 efflux is prone to experimental artifacts that could account for the reported response, papers published since the start of the current research continue to report an instantaneous depression of respiratory CO2 efflux by elevation of [CO2]. Here, these artifacts are avoided by use of a high-resolution dual channel oxygen analyzer within an open gas exchange system to measure respiratory 02 uptake in normal air. Leaf 02 uptake was determined in response to instantaneous elevation of [CO2] in nine contrasting species and to long-term elevation in seven species from four of the DOE-sponsored long-term elevated [CO2] field experiments. Over one thousand separate measurements of respiration failed to reveal any decrease in respiratory 02 uptake with an instantaneous increase in [CO2]. Respiration was found insensitive not only to doubling [CO2], but also to a five-fold increase and to decrease to zero.

  15. Urinary 1-hydroxypyrene concentrations in Chinese coke oven workers relative to job category, respirator usage, and cigarette smoking

    SciTech Connect (OSTI)

    Bo Chen; Yunping Hu; Lixing Zheng; Qiangyi Wang; Yuanfen Zhou; Taiyi Jin [Fudan University, Shanghai (China). School of Public Health

    2007-09-15T23:59:59.000Z

    1-Hydroxypyrene (1-OHP) is a biomarker of recent exposure to polycyclic aromatic hydrocarbons (PAHs). We investigated whether urinary 1-OHP concentrations in Chinese coke oven workers (COWs) are modulated by job category, respirator usage, and cigarette smoking. The present cross-sectional study measured urinary 1-OHP concentrations in 197 COWs from Coking plant I and 250 COWs from Coking plant II, as well as 220 unexposed referents from Control plant I and 56 referents from Control plant II. Urinary 1-OHP concentrations (geometric mean, {mu}mol/mol creatinine) were 5.18 and 4.21 in workers from Coking plants I and II, respectively. The highest 1-OHP levels in urine were found among topside workers including lidmen, tar chasers, and whistlers. Benchmen had higher 1-OHP levels than other workers at the sideoven. Above 75% of the COWs exceeded the recommended occupational exposure limit of 2.3 {mu}mol/mol creatinine. Respirator usage and increased body mass index (BMI) slightly reduced 1-OHP levels in COWs. Cigarette smoking significantly increased urinary 1-OHP levels in unexposed referents but had no effect in COWs. Chinese COWs, especially topside workers and benchmen, are exposed to high levels of PAHs. Urinary 1-OHP concentrations appear to be modulated by respirator usage and BMI in COWs, as well as by smoking in unexposed referents.

  16. Next Generation Fast RF Interlock Module and ATCA Adapter for ILC High Availability RF Test Station Demonstration

    SciTech Connect (OSTI)

    Larsen, R

    2009-10-17T23:59:59.000Z

    High availability interlocks and controls are required for the ILC (International Linear Collider) L-Band high power RF stations. A new F3 (Fast Fault Finder) VME module has been developed to process both fast and slow interlocks using FPGA logic to detect the interlock trip excursions. This combination eliminates the need for separate PLC (Programmable Logic Controller) control of slow interlocks. Modules are chained together to accommodate as many inputs as needed. In the next phase of development the F3's will be ported to the new industry standard ATCA (Advanced Telecom Computing Architecture) crate (shelf) via a specially designed VME adapter module with IPMI (Intelligent Platform Management Interface). The goal is to demonstrate auto-failover and hot-swap for future partially redundant systems.

  17. Effects of drinking water temperature on respiration rates, body temperatures, dry matter intake, and milk production in lactating Holstein cows in summer 

    E-Print Network [OSTI]

    Milam, Kyle Zohn

    1985-01-01T23:59:59.000Z

    EFFECTS OF DRINKING WATER TEMPERATURE ON RESPIRATION RATES, BODY TEMPERATURES, DRY MATTER INTAKE, AND MILK PRODUCTION IN LACTATING HOLSTEIN COWS IN SUMMER A Thesis by KYLE ZOHN MILAM Submitted to the Graduate College of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1985 Major Subject: Nutrition EFFECTS OF DRINKING WATER TEMPERATURE ON RESPIRATION RATES, BODY TEMPERATURES, DRY MATTER INTAKE, AND MILK PRODUCTION IN LACTATING HOLSTEIN...

  18. Solid state RF power: The route to 1W per euro cent

    SciTech Connect (OSTI)

    Heid, Oliver [Siemens AG, Mozartstrasse 57, Erlangen (Germany)

    2013-04-19T23:59:59.000Z

    In most particle accelerators RF power is a decisive design constraint due to high costs and relative inflexibility of current electron beam based RF sources, i.e. Klystrons, Magnetrons, Tetrodes etc. At VHF/UHF frequencies the transition to solid state devices promises to fundamentally change the situation. Recent progress brings 1 Watt per Euro cent installed cost within reach. We present a Silicon Carbide semiconductor solution utilising the Solid State Direct Drive technology at unprecedented efficiency, power levels and power densities. The proposed solution allows retrofitting of existing RF accelerators and opens the route to novel particle accelerator concepts.

  19. RF-driven ion source with a back-streaming electron dump

    DOE Patents [OSTI]

    Kwan, Joe; Ji, Qing

    2014-05-20T23:59:59.000Z

    A novel ion source is described having an improved lifetime. The ion source, in one embodiment, is a proton source, including an external RF antenna mounted to an RF window. To prevent backstreaming electrons formed in the beam column from striking the RF window, a back streaming electron dump is provided, which in one embodiment is formed of a cylindrical tube, open at one end to the ion source chamber and capped at its other end by a metal plug. The plug, maintained at the same electrical potential as the source, captures these backstreaming electrons, and thus prevents localized heating of the window, which due to said heating, might otherwise cause window damage.

  20. 28 IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS, VOL. 1, NO. 1, MARCH 2007 Feedback Analysis and Design of RF Power Links for

    E-Print Network [OSTI]

    Sarpeshkar, Rahul

    structure of an inductive power link system for an example implant. An RF power amplifier drives a primary Analysis and Design of RF Power Links for Low-Power Bionic Systems Michael W. Baker, Student Member, IEEE for analyzing and designing RF power links for transcutaneous bionic systems, i.e., between an external RF coil

  1. Composition-Morphology-Property Relations For Giant Magnetoresistance Multilayers Grown By RF Diode Sputtering

    E-Print Network [OSTI]

    Wadley, Haydn

    University of Virginia, Charlottesville, VA 22903 D. Brownell Nonvolatile Electronics, Inc. Eden Prairie, MN, Inc. (Eden Prairie, MN) using a Randex Model 2400-6J RF diode system. Briefly, the diameter

  2. High gain proportional rf control stability at TESLA cavities Elmar Vogel

    E-Print Network [OSTI]

    High gain proportional rf control stability at TESLA cavities Elmar Vogel Deutsches Elektronen) based on TESLA technology. Additional control loops improve the field regulation by treating repetitive loops is desirable for the strong suppression of nonpredictive and nonrepetitive disturbances. TESLA

  3. Thesis for the Degree of Licentiate of Engineering CTH-RF-190 Development and Investigation of

    E-Print Network [OSTI]

    Haviland, David

    Thesis for the Degree of Licentiate of Engineering CTH-RF-190 Development and Investigation (ADS), Feynman-alpha formulae, source modulation method, point kinetics #12;#12;This licentiate thesis

  4. The Design and Development of a Hybrid RF/Laser Radar System for Measuring Changes in

    E-Print Network [OSTI]

    Kansas, University of

    transmit power and higher PRF. RF pulse compression is used to improve system performance further. Receiver compression. Compared to laser radars like GLAS and MOLA, this sensor requires a lower peak transmit power Compression .......................................................... 14 2.6 Coherent Integration

  5. Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources 

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01T23:59:59.000Z

    The primary design criterion for RF transmit coils for MRI is uniform transverse magnetic (B1) field. Currently, most high frequency transmit coils are designed as periodic, symmetric structures that are resonant at the ...

  6. Study of RF Plasma Technology Applied to Air-Breathing Electric Propulsion

    E-Print Network [OSTI]

    Shyy, Wei

    Foster, thank you for being so encouraging, for listening to and understanding the woes of RF plasma research, and for being so friendly at conferences and in the hallways. Professor Longmier, welcome

  7. High-power rf-pulsed modulators for the Los Alamos free-electron laser

    SciTech Connect (OSTI)

    Johnson, W.J.D.; Lynch, M.T.; Tallerico, P.J.; Keffeler, D.R.; Hornkohl, J.O.

    1987-09-01T23:59:59.000Z

    In the rf-driven free-electron laser (FEL) at the Los Alamos National Laboratory, there are two pulsed-power rf modulators as sources for two tandem, side-coupled 20-MeV linear accelerators. The rf power used to control the cavity fields is supplied by two 5.5-MW modulating anode klystrons operating at a center frequency of 1300.2 MHz. The modulation of the 125 kV klystron is achieved by using a triode switch tube that provides a pulse width up to 300 ..mu..s and a pulse repetition rate up to 10 Hz. This paper describes the present configuration of these two duplicate systems and presents plans for meeting the requirements of future rf FEL experiments at Los Alamos. 12 refs., 5 figs.

  8. PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform Synthesis,

    E-Print Network [OSTI]

    Purdue University

    PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform, Shijun Xiao Funding from ARO, DARPA, and NSF #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER performance (spectral engineering, dispersion compensation) #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL

  9. Design of a high quality factor spiral inductors in RF MCM-D

    E-Print Network [OSTI]

    Peters, Joshua, 1981-

    2004-01-01T23:59:59.000Z

    This thesis studies the design and fabrication of spiral inductors for use in Radio Frequency (RF) applications. A design methodology is developed to search an inductor design space efficiently using existing simulation ...

  10. A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor

    SciTech Connect (OSTI)

    Xiao, Binping [Brookhaven National Laboratory, Upton, New York (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-02-01T23:59:59.000Z

    There is a need to understand the intrinsic limit of radiofrequency (RF) surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance (Rs) of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and FNAL with carefully, yet differently, prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.

  11. Detection technique and front-end RF tunable filter for cognitive radio systems

    E-Print Network [OSTI]

    Park, Sanghoon

    2010-01-01T23:59:59.000Z

    dual-mode WiMAX/WLAN direct- conversion receiver,” in Proc.Hamilton, “Aspects of direct conversion receiver design,” inand M. Ismail, “A direct conversion WiMAX RF receiver front-

  12. Tunable Substrate Integrated Waveguide Filters Implemented with PIN Diodes and RF MEMS Switches 

    E-Print Network [OSTI]

    Armendariz, Marcelino

    2012-02-14T23:59:59.000Z

    This thesis presents the first fully tunable substrate integrated waveguide (SIW) filter implemented with PIN diodes and RF MEMS switches. The methodology for tuning SIW filters is explained in detail and is used to create three separate designs...

  13. Tunable Substrate Integrated Waveguide Filters Implemented with PIN Diodes and RF MEMS Switches

    E-Print Network [OSTI]

    Armendariz, Marcelino

    2012-02-14T23:59:59.000Z

    This thesis presents the first fully tunable substrate integrated waveguide (SIW) filter implemented with PIN diodes and RF MEMS switches. The methodology for tuning SIW filters is explained in detail and is used to create three separate designs...

  14. Selecting Fractionators for Product Composition Control

    E-Print Network [OSTI]

    Griffin, D. E.; Anderson, J. E.

    1979-01-01T23:59:59.000Z

    The benefits resulting from computer control of fractionators have been proven in many installations. These benefits include energy savings, increased throughput, higher recovery product upgrade and smoother operation. As a basis for understanding...

  15. Bio-oil fractionation and condensation

    DOE Patents [OSTI]

    Brown, Robert C; Jones, Samuel T; Pollard, Anthony

    2013-07-02T23:59:59.000Z

    A method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents is described. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also described are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.

  16. Algebra of Fractions of Algebra with Conjugation

    E-Print Network [OSTI]

    Aleks Kleyn

    2012-05-09T23:59:59.000Z

    In the paper, I considered construction of algebra of fractions of algebra with conjugation. I also considered algebra of polynomials and algebra of rational mappings over algebra with conjugation.

  17. Automatic Pole and Q-Value Extraction for RF Structures

    SciTech Connect (OSTI)

    C. Potratz, H.-W. Glock, U. van Rienen, F. Marhauser

    2011-09-01T23:59:59.000Z

    The experimental characterization of RF structures like accelerating cavities often demands for measuring resonant frequencies of Eigenmodes and corresponding (loaded) Q-values over a wide spectral range. A common procedure to determine the Q-values is the -3dB method, which works well for isolated poles, but may not be applicable directly in case of multiple poles residing in close proximity (e.g. for adjacent transverse modes differing by polarization). Although alternative methods may be used in such cases, this often comes at the expense of inherent systematic errors. We have developed an automation algorithm, which not only speeds up the measurement time significantly, but is also able to extract Eigenfrequencies and Q-values both for well isolated and overlapping poles. At the same time the measurement accuracy may be improved as a major benefit. To utilize this procedure merely complex scattering parameters have to be recorded for the spectral range of interest. In this paper we present the proposed algorithm applied to experimental data recorded for superconducting higher-order-mode damped multi-cell cavities as an application of high importance.

  18. Operation of the superconducting RF photo gun at ELBE

    E-Print Network [OSTI]

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, Ch; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2012-01-01T23:59:59.000Z

    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3˝ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 ?A average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  19. Operation of the superconducting RF photo gun at ELBE

    E-Print Network [OSTI]

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2011-01-01T23:59:59.000Z

    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3˝ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 µA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  20. Carbon isotope fractionation in autotrophic Chromatium

    E-Print Network [OSTI]

    Wong, William Wai-Lun

    1974-01-01T23:59:59.000Z

    CARSON ISOTOPE FRACTIONATION IN AUTOTPOPHIC CHROYATIUN A Thesis 'JILLIAJJ J JAI LJJN BONG Submitted to the Graduate College of Texas A&H University in partial fulfillment of the requirenent for the degree of PLASTER OF SCIENCE August 1974...) August 1974 ABSTRACT Carbon Isotope Fractionation in Autotrophic Chromatium (August 1974) blilliam Wai-Lun Wang, B. S. , Texas Lutheran College Co-Chairmen of Advisory Committee: Dr. Isilliam N. Sackett Dr. Chauncey P. . Benedict Bacterial cells...

  1. Development of plutonium aerosol fractionation system 

    E-Print Network [OSTI]

    Mekala, Malla R.

    1993-01-01T23:59:59.000Z

    DEVELOPMENT OF A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August... 1993 Major Subject: Mechanical Engineering DEVELOPMENT OP A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Approved as to style and content by: A. R. McFarland (Chair of Committee) N. K. Anand (Mer toer) (', & C. B...

  2. Exact Methods In Fractional Combinatorial Optimization 

    E-Print Network [OSTI]

    Ursulenko, Oleksii

    2011-02-22T23:59:59.000Z

    -to-time ratio cycle problem, also known as the tramp steamer problem [2]. A short survey on fractional combinatorial optimization problems and related solution approaches can be found in [35]. Recently, Skiscim and Palocsay [39, 40] have introduced a..., approximability and local search, are addressed in [32, 33]. Generally speaking, multiple-ratio problems arise in case of multiple fractional performance metrics that need to be optimized, e.g., a eet of cargo ships in the tramp steamer problem. Related...

  3. Important requirements for RF generators for Accelerator-Driven Transmutation Technologies (ADTT)

    SciTech Connect (OSTI)

    Lynch, M.T.; Tallerico, P.J.; Lawrence, G.P.

    1994-09-01T23:59:59.000Z

    All Accelerator-Driven Transmutation applications require very large amounts of RF Power. For example, one version of a Plutonium burning system requires an 800-MeV, 80-mA, proton accelerator running at 100% duty factor. This accelerator requires approximately 110-MW of continuous RF power if one assumes only 10% reserve power for control of the accelerator fields. In fact, to minimize beam spill, the RF controls may need as much as 15 to 20% of reserve power. In addition, unlike an electron accelerator in which the beam is relativistic, a failed RF station can disturb the synchronism of the beam, possibly shutting down the entire accelerator. These issues and more lead to a set of requirements for the RF generators which are stringent, and in some cases, conflicting. In this paper, we will describe the issues and requirements, and outline a plan for RF generator development to meet the needs of the Accelerator-Driven Transmutation Technologies. The key issues which will be discussed include: operating efficiency, operating linearity, effect on the input power grid, bandwidth, gain, reliability, operating voltage, and operating current.

  4. Phase Noise of the Radio Frequency (RF) Beatnote Generated by a Dual-Frequency VECSEL

    E-Print Network [OSTI]

    Syamsundar De; Abdelkrim El Amili; Ihsan Fsaifes; Grégoire Pillet; Ghaya Baili; Fabienne Goldfarb; Mehdi Alouini; Isabelle Sagnes; Fabien Bretenaker

    2013-11-13T23:59:59.000Z

    We analyze, both theoretically and experimentally, the phase noise of the radio frequency (RF) beatnote generated by optical mixing of two orthogonally polarized modes in an optically pumped dual-frequency Vertical External Cavity Surface Emitting Laser (VECSEL). The characteristics of the RF phase noise within the frequency range of 10 kHz - 50 MHz are investigated for three different nonlinear coupling strengths between the two lasing modes. In the theoretical model, we consider two different physical mechanisms responsible for the RF phase noise. In the low frequency domain (typically below 500 kHz), the dominant contribution to the RF phase noise is shown to come from the thermal fluctuations of the semicondutor active medium induced by pump intensity fluctuations. However, in the higher frequency domain (typically above 500 kHz), the main source of RF phase noise is shown to be the pump intensity fluctuations which are transfered to the intensity noises of the two lasing modes and then to the phase noise via the large Henry factor of the semiconductor gain medium. For this latter mechanism, the nonlinear coupling strength between the two lasing modes is shown to play an important role in the value of the RF phase noise. All experimental results are shown to be in good agreement with theory.

  5. RF Design and Operating Results for a New 201.25 MHz RF Power Amplifier for LANSCE

    SciTech Connect (OSTI)

    Lyles, John T. [Los Alamos National Laboratory; Baca, David M. [Los Alamos National Laboratory; Bratton, Ray E. [Los Alamos National Laboratory; Brennan, Nicholas W. [Los Alamos National Laboratory; Bultman, Nathan K. [Los Alamos National Laboratory; Chen, Zukun [Los Alamos National Laboratory; Davis, Jerry L. [Los Alamos National Laboratory; Naranjo, Angela C. [Los Alamos National Laboratory; Rees, Daniel E. [Los Alamos National Laboratory; Sandoval, Gilbert M. Jr. [Los Alamos National Laboratory; Summers, Richard D. [Los Alamos National Laboratory

    2011-01-01T23:59:59.000Z

    A prototype VHF RF Final Power Amplifier (FPA) for Los Alamos Neutron Science Center (LANSCE) has been designed, fabricated, and tested. The cavity amplifier has met the goals of generating 2.5 MW peak and 260 kW of average power, at an elevation of 2.1 km. It was designed to use a Thales TH628 Diacrode{sup R}, a state-of-art tetrode power tube that is double-ended, providing roughly twice the power of a conventional tetrode. The amplifier is designed with tunable input and output transmission line cavity circuits, a grid decoupling circuit, an adjustable output coupler, TE mode suppressors, blocking, bypassing and decoupling capacitors, and a cooling system. The tube is connected in a full wavelength output circuit, with the lower main tuner situated 3/4{lambda} from the central electron beam region in the tube and the upper slave tuner 1/4{lambda} from the same point. We summarize the design processes and features of the FPA along with significant test results. A pair of production amplifiers are planned to be power-combined and installed at the LANSCE DTL to return operation to full beam duty factor.

  6. RF properties of periodic accelerating structures for linear colliders

    SciTech Connect (OSTI)

    Wang, J.W.

    1989-07-01T23:59:59.000Z

    With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.

  7. Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

    SciTech Connect (OSTI)

    Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC

    2009-08-04T23:59:59.000Z

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  8. average void fraction: Topics by E-print Network

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

    void fraction correlations and experimental Ghajar, Afshin J. 4 Measurement of the fractal order of wall void fraction during nucleate boiling Engineering Websites Summary:...

  9. Method Development: Identification of the Soluble Organic Fraction...

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

    Method Development: Identification of the Soluble Organic Fraction of Particulate Matter on DPF Soot Method Development: Identification of the Soluble Organic Fraction of...

  10. Fractionation of Oxygen Isotopes in Phosphate during its Interactions...

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

    Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides. Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides....

  11. Quantum probes for fractional Gaussian processes

    E-Print Network [OSTI]

    Matteo G. A. Paris

    2014-07-19T23:59:59.000Z

    We address the characterization of classical fractional random noise via quantum probes. In particular, we focus on estimation and discrimination problems involving the fractal dimension of the trajectories of a system subject to fractional Brownian noise. We assume that the classical degree of freedom exposed to the environmental noise is coupled to a quantum degree of freedom of the same system, e.g. its spin, and exploit quantum limited measurements on the spin part to characterize the classical fractional noise. More generally, our approach may be applied to any two-level system subject to dephasing perturbations described by fractional Brownian noise, in order to assess the precision of quantum limited measurements in the characterization of the external noise. In order to assess the performances of quantum probes we evaluate the Bures metric, as well as the Helstrom and the Chernoff bound, and optimize their values over the interaction time. We find that quantum probes may be successfully employed to obtain a reliable characterization of fractional Gaussian process when the coupling with the environment is weak or strong. In the first case decoherence is not much detrimental and for long interaction times the probe acquires information about the environmental parameters without being too much mixed. Conversely, for strong coupling, information is quickly impinged on the quantum probe and can effectively retrieved by measurements performed in the early stage of the evolution. In the intermediate situation, none of the two above effects take place: information is flowing from the environment to the probe too slowly compared to decoherence, and no measurements can be effectively employed to extract it from the quantum probe. The two regimes of weak- and strong-coupling are defined in terms of a threshold value of the coupling, which itself increases with the fractional dimension.

  12. Cross-shift peak expiratory flow changes are unassociated with respirable coal dust exposure among South African coal miners

    SciTech Connect (OSTI)

    Naidoo, R.N.; Robins, T.G.; Becklake, M.; Seixas, N.; Thompson, M.L. [University of KwaZulu Natal, Durban (South Africa)

    2007-12-15T23:59:59.000Z

    he objectives of this study were to determine whether cross-shift changes in peak expiratory flow rate (PEFR) were related to respirable dust exposure in South African coalminers. Fifty workers were randomly selected from a cohort of 684 miners from 3 bituminous coal mines in Mpumalanga, South Africa. Peak expiratory efforts were measured prior to the commencement of the shift, and at the end of the shift on at least two occasions separated by at least 2 weeks, with full shift personal dust sampling being conducted on each occasion for each participant. Interviews were conducted, work histories were obtained and cumulative exposure estimates were constructed. Regression models examined the associations of cross-shift changes in PEFR with current and cumulative exposure, controlling for shift, smoking and past history of tuberculosis. There were marginal differences in cross-shift PEFR (ranging from 0.1 to 2 L/min). Linear regression analyses showed no association between cross-shift change in PEFR and current or cumulative exposure. The specific shift worked by participants in the study showed no effect. Our study showed no association between current respirable dust exposure and cross-shift changes in PEFR. There was a non-significant protective effect of cumulative dust exposure on the outcome, suggesting the presence of a 'healthy worker survivor effect' in this data.

  13. The Fractional Kinetic Equation and Thermonuclear Functions

    E-Print Network [OSTI]

    H. J. Haubold; A. M. Mathai

    2000-01-16T23:59:59.000Z

    The paper discusses the solution of a simple kinetic equation of the type used for the computation of the change of the chemical composition in stars like the Sun. Starting from the standard form of the kinetic equation it is generalized to a fractional kinetic equation and its solutions in terms of H-functions are obtained. The role of thermonuclear functions, which are also represented in terms of G- and H-functions, in such a fractional kinetic equation is emphasized. Results contained in this paper are related to recent investigations of possible astrophysical solutions of the solar neutrino problem.

  14. Simulation of RF Cavity Dark Current In Presence of Helical Magnetic Field

    SciTech Connect (OSTI)

    Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

    2012-05-01T23:59:59.000Z

    In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

  15. Simulation of RF Cavity Dark Current in Presence of Helical Magnetic Field

    SciTech Connect (OSTI)

    Romanov, Gennady; Kashikhin, Vladimir; /Unlisted

    2010-09-01T23:59:59.000Z

    In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

  16. Stabilizing effect of a double-harmonic RF system in the CERN PS

    SciTech Connect (OSTI)

    Bhat, C.; /Fermilab; Caspers, F.; Damerau, H.; Hancock, S.; Mahner, E.; Zimmermann, F.; /CERN

    2009-04-01T23:59:59.000Z

    Motivated by the discussions on scenarios for LHC upgrades, beam studies on the stability of flat bunches in a double-harmonic RF system have been conducted in the CERN Proton Synchrotron (PS). Injecting nearly nominal LHC beam intensity per cycle, 18 bunches are accelerated on harmonic h = 21 to 26GeV with the 10MHz RF system. On the flat-top, all bunches are then transformed to flat bunches by adiabatically adding RF voltage at h = 42 from a 20 MHz cavity in anti-phase to the h = 21 system. The voltage ratio V (h42)/V (h21) of about 0.5 was set according to simulations. For the next 140 ms, longitudinal profiles show stable bunches in the double-harmonic RF bucket until extraction. Without the second harmonic component, coupled-bunch oscillations are observed. The flatness of the bunches along the batch is analyzed as a measure of the relative phase error between the RF systems due to beam loading. The results of beam dynamics simulations and their comparison with the measured data are presented.

  17. Multipole and field uniformity tailoring of a 750 MHz rf dipole

    SciTech Connect (OSTI)

    Delayen, Jean R. [JLAB, Old Dominion University; Castillo, Alejandro [JLAB, Old Dominion University

    2014-12-01T23:59:59.000Z

    In recent years great interest has been shown in developing rf structures for beam separation, correction of geometrical degradation on luminosity, and diagnostic applications in both lepton and hadron machines. The rf dipole being a very promising one among all of them. The rf dipole has been tested and proven to have attractive properties that include high shunt impedance, low and balance surface fields, absence of lower order modes and far-spaced higher order modes that simplify their damping scheme. As well as to be a compact and versatile design in a considerable range of frequencies, its fairly simple geometry dependency is suitable both for fabrication and surface treatment. The rf dipole geometry can also be optimized for lowering multipacting risk and multipole tailoring to meet machine specific field uniformity tolerances. In the present work a survey of field uniformities, and multipole contents for a set of 750 MHz rf dipole designs is presented as both a qualitative and quantitative analysis of the inherent flexibility of the structure and its limitations.

  18. Inverse Problems for Fractional Diffusion Equations

    E-Print Network [OSTI]

    Zuo, Lihua

    2013-06-21T23:59:59.000Z

    and preliminaries in Section 1 and 2, in the third section we consider our first inverse boundary problem. This is where an unknown boundary condition is to be determined from overposed data in a time- fractional diffusion equation. Based upon the fundamental...

  19. Introduction Spectrum Phases Fractionization Kitaev Honeycomb Model

    E-Print Network [OSTI]

    Fractionization Spin ! Majorana Transformation Key Idea - Factorize the Pauli matrices by moving to a higher by Majorana fermions 2 Gapped and gapless phases 3 Relation to the Toric Code 4 Eect of a magnetic field dimensional subspace Can replace each complex fermionic degree a of freedom with two Majoranas 1 and 2 1 1 = a

  20. 1Fractions and Chemistry Because molecules and

    E-Print Network [OSTI]

    1Fractions and Chemistry Because molecules and atoms come in 'integer' packages, the ratios of gasoline (ethane) are combined with 7 molecules of oxygen you get 4 molecules of carbon dioxide and 6;1 Answer Key Problem 1 - What makes your car go: When 2 molecules of gasoline (ethane) are combined with 7

  1. World Volume Action for Fractional Branes

    E-Print Network [OSTI]

    Merlatti, P

    2001-01-01T23:59:59.000Z

    We study the world volume action of fractional Dp-branes of type IIA string theory compactified on the orbifold T^4/Z_2. The geometric relation between these branes and wrapped branes is investigated using conformal techniques. In particular we examine in detail various scattering amplitudes and find that the leading low-energy interactions are consistent with the boundary action derived geometrically.

  2. World Volume Action for Fractional Branes

    E-Print Network [OSTI]

    P. Merlatti; G. Sabella

    2001-01-11T23:59:59.000Z

    We study the world volume action of fractional Dp-branes of type IIA string theory compactified on the orbifold T^4/Z_2. The geometric relation between these branes and wrapped branes is investigated using conformal techniques. In particular we examine in detail various scattering amplitudes and find that the leading low-energy interactions are consistent with the boundary action derived geometrically.

  3. Infrared spectroscopy of diatomic molecules - a fractional calculus approach

    E-Print Network [OSTI]

    Richard Herrmann

    2012-12-12T23:59:59.000Z

    The eigenvalue spectrum of the fractional quantum harmonic oscillator is calculated numerically solving the fractional Schr\\"odinger equation based on the Riemann and Caputo definition of a fractional derivative. The fractional approach allows a smooth transition between vibrational and rotational type spectra, which is shown to be an appropriate tool to analyze IR spectra of diatomic molecules.

  4. A Fractional Lie Group Method For Anomalous Diffusion Equations

    E-Print Network [OSTI]

    Guo-cheng Wu

    2010-09-21T23:59:59.000Z

    Lie group method provides an efficient tool to solve a differential equation. This paper suggests a fractional partner for fractional partial differential equations using a fractional characteristic method. A space-time fractional diffusion equation is used as an example to illustrate the effectiveness of the Lie group method.

  5. Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron

    E-Print Network [OSTI]

    Brian Chase; Ralph Pasquinelli; Ed Cullerton; Philip Varghese

    2014-11-21T23:59:59.000Z

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  6. Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron

    E-Print Network [OSTI]

    Chase, Brian; Cullerton, Ed; Varghese, Philip

    2015-01-01T23:59:59.000Z

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  7. Commissioning the new high power rf system for the AGS with high intensity beam

    SciTech Connect (OSTI)

    Brennan, J.M.; Ciardullo, D.J.; Deng, D.P; Hayes, T.; Onillon, E.; Otis, A.; Sanders, R.T.; Zaltsman, A.

    1994-08-01T23:59:59.000Z

    A new high power rf system has been installed in the AGS in order to raise the beam loading limit to beyond 6 {times} 10{sup 13} protons per pulse. The old system was limited to 2.2 {times} 10{sup l3} ppp by: available real power, multi-loop instability, and transient beam loading during batch filling from the Booster. The key components of the new system are: new power amplifiers in the tunnel using the Thomson-CSF TH573 300kW tetrode, rf feedback around the power stage, and reduction of the 10 cavities` R/Q by 1.8 by additional gap capacitors. Commissioning of the new rf system with high intensity beam is described. The intensity goal for the 1994 running period is 4 {times} 10{sup 13} ppp. To date, 3.7 {times} 10{sup 13} ppp has been achieved.

  8. Final Technical Report- Back-gate Field Emission-based Cathode RF Electron Gun

    SciTech Connect (OSTI)

    McGuire, Gary; Martin, Allen; Noonan, John

    2010-10-30T23:59:59.000Z

    The objective was to complete the design of an electron gun which utilizes a radio frequency (RF) power source to apply a voltage to a field emission (FE) cathode, a so called cold cathode, in order to produce an electron beam. The concept of the RF electron gun was originally conceived at Argonne National Laboratory but never reduced to practice. The research allowed the completion of the design based upon the integration of the FE electron source. Compared to other electron guns, the RF gun is very compact, less than one third the size of other comparable guns, and produces a high energy (to several MeV), high quality, high power electron beam with a long focal length with high repetition rates. The resultant electron gun may be used in welding, materials processing, analytical equipment and waste treatment.

  9. Phase-resolved optical emission of dusty rf discharges: Experiment and simulation

    SciTech Connect (OSTI)

    Melzer, Andre; Huebner, Simon; Lewerentz, Lars; Schneider, Ralf [Institut fuer Physik, Ernst-Moritz-Arndt-Universiaet, D-17489 Greifswald (Germany); Matyash, Konstantin [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, Ramana [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

    2011-03-15T23:59:59.000Z

    The spectral emission of atoms in a dusty radio frequence (rf) discharge plasma in argon and helium has been measured with a gated ICCD camera. The spatially and temporally resolved emission/excitation of the argon and helium atoms during the rf cycle in the dusty discharge was compared to the dust-free case. In the bulk plasma above the dust cloud, the emission is clearly enhanced in the dusty discharge with respect to the pure discharge, whereas in the sheath the emission is reduced. In addition, the emission of a dusty argon plasma is studied via particle-particle particle-mesh (P{sup 3}M) simulations. The rf dynamics with a single dust particle trapped in the sheath was calculated. Like in the experiment the dust modifies the atomic emission. The spatiotemporal excitation pattern of the experiment is reproduced and a detailed understanding of the difference in excitation of the discharge with and without dust is presented.

  10. RF transmission line and drill/pipe string switching technology for down-hole telemetry

    DOE Patents [OSTI]

    Clark, David D. (Santa Fe, NM); Coates, Don M. (Santa Fe, NM)

    2007-08-14T23:59:59.000Z

    A modulated reflectance well telemetry apparatus having an electrically conductive pipe extending from above a surface to a point below the surface inside a casing. An electrical conductor is located at a position a distance from the electrically conductive pipe and extending from above the surface to a point below the surface. Modulated reflectance apparatus is located below the surface for modulating well data into a RF carrier transmitted from the surface and reflecting the modulated carrier back to the surface. A RF transceiver is located at the surface and is connected between the electrically conductive pipe and the electrical conductor for transmitting a RF signal that is confined between the electrically conductive well pipe and the electrical conductor to the modulated reflectance apparatus, and for receiving reflected data on the well from the modulated reflectance apparatus.

  11. Effect of RF Gradient upon the Performance of the Wisconsin SRF Electron Gun

    SciTech Connect (OSTI)

    Bosch, Robert [SRC U. Wisconsin-Madison; Legg, Robert A. [JLAB

    2013-12-01T23:59:59.000Z

    The performance of the Wisconsin 200-MHz SRF electron gun is simulated for several values of the RF gradient. Bunches with charge of 200 pC are modeled for the case where emittance compensation is completed during post-acceleration to 85 MeV in a TESLA module. We first perform simulations in which the initial bunch radius is optimal for the design gradient of 41 MV/m. We then optimize the radius as a function of RF gradient to improve the performance for low gradients.

  12. Method and apparatus for transferring and injecting rf energy from a generator to a resonant load

    DOE Patents [OSTI]

    Hoffert, William J. (Albuquerque, NM)

    1987-01-01T23:59:59.000Z

    Improved apparatus and method are provided for the coherent amplification and injection of radio-frequency (rf) energy into a load cavity using a plurality of amplifier tubes. A plurality of strip line cavities (30, 32, 34, 36, 40, 42, 44) are laterally joined to define a continuous closed cavity (48), with an amplifier tube (50, 52, 54, 56, 58, 60, 62, 64) mounted within each resonant strip cavity. Rf energy is injected into the continuous cavity (48) from a single input (70) for coherent coupling to all of the amplifier tubes for amplification and injection into the load cavity (76).

  13. Plasma sweeper to control the coupling of RF power to a magnetically confined plasma

    DOE Patents [OSTI]

    Motley, Robert W. (Princeton, NJ); Glanz, James (Lawrenceville, NJ)

    1985-01-01T23:59:59.000Z

    A device for coupling RF power (a plasma sweeper) from a phased waveguide array for introducing RF power to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the phased waveguide array; and a potential source coupled to the electrode for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.

  14. Intelligent Low-level RF System by Non-destructive Beam Monitoring Device for Cyclotrons

    E-Print Network [OSTI]

    Malafeh, M S Sharifi Asadi; Afarideh, H; Chai, J S

    2015-01-01T23:59:59.000Z

    The project of a10MeV PET cyclotron accelerator for medical diagnosis and treatment was started at Amirkabir University of Technology in 2012. The low-level RF system of cyclotron accelerator is designed to stabilize acceleration voltage and control the resonance frequency of the cavity. In this work Intelligent Low Level Radio Frequency Circuit or ILLRF suitable for Most of the AVF cyclotron accelerators was designed by the beam monitoring device and narrow band tunable band-pass filter. In this design, for the RF phase detection does not need to signal processing by microcontroller

  15. Design of HOM coupler prototype for the APT superconducting RF cavities

    SciTech Connect (OSTI)

    Kuzminski, J. (Jozef); Spalek, G. (George); Bourque, R. F. (Robert F.)

    2001-01-01T23:59:59.000Z

    Beam dynamics calculations for the Accelerator Production of Tritium (APT) proton linac suggest that wakefields, which are excited during beam operation, would not lead to beam-breakup instabilities. However, in the superconducting (SC) radio-frequency (RF) cavities of the APT linac, higher-order modes (HOMs), whose frequencies are below the beam tube cut-off fiequency, can be sufficiently excited by the beam to add significantly to the heat load removed by the helium refrigerator. In this paper, we present a design of an HOM coupler for the APT RF cavities that will remove this power to a resistive load at room temperature.

  16. High power tests of dressed supconducting 1.3 GHz RF cavities

    SciTech Connect (OSTI)

    Hocker, A.; Harms, E.R.; Lunin, A.; Sukhanov, A.; /Fermilab

    2011-03-01T23:59:59.000Z

    A single-cavity test cryostat is used to conduct pulsed high power RF tests of superconducting 1.3 GHz RF cavities at 2 K. The cavities under test are welded inside individual helium vessels and are outfitted ('dressed') with a fundamental power coupler, higher-order mode couplers, magnetic shielding, a blade tuner, and piezoelectric tuners. The cavity performance is evaluated in terms of accelerating gradient, unloaded quality factor, and field emission, and the functionality of the auxiliary components is verified. Test results from the first set of dressed cavities are presented here.

  17. Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a,

    E-Print Network [OSTI]

    Rosen, Matthew S

    Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a: Received 6 January 2012 Revised 14 March 2012 Available online 28 March 2012 Keywords: Nuclear singlet of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field

  18. Open-Thru de-embedding for Graphene RF devices Giancarlo Vincenzi, George Deligeorgis, Fabio Coccetti and Patrick Pons

    E-Print Network [OSTI]

    Boyer, Edmond

    Open-Thru de-embedding for Graphene RF devices Giancarlo Vincenzi, George Deligeorgis, Fabio, LAAS, F-31400 Toulouse, France Abstract--The performances of graphene RF devices rely heavily-embedding technique adapted to the needs of microwave graphene devices is presented. Two standards and only one step

  19. A Fiber-Optic-Based 1550-nm Laser Radar Altimeter with RF Pulse Compression Christopher Allen, Sivaprasad Gogineni

    E-Print Network [OSTI]

    Kansas, University of

    A Fiber-Optic-Based 1550-nm Laser Radar Altimeter with RF Pulse Compression Christopher Allen-the-shelf fiber-optic components and traditional RF and digital signal processing techniques to achieve fine erbium-doped fiber amplifiers (EDFAs) could be used to provide optical gain. The transmitted signal

  20. Development of a 1319 nm Laser Radar using Fiber-Optics and RF Pulse Compression: Receiver Characterization

    E-Print Network [OSTI]

    Kansas, University of

    Development of a 1319 nm Laser Radar using Fiber-Optics and RF Pulse Compression: Receiver and commercially available fiber-optic technologies. We use radio frequency (RF) pulse compression and digital commensurate with the desired range accuracy. With today's off-the-shelf fiber-optic components, multi

  1. Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites

    DOE Patents [OSTI]

    Norem, James H.; Pellin, Michael J.

    2013-06-11T23:59:59.000Z

    Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

  2. Scanning Tunneling Microscopy Study of Cr-doped GaN Surface Grown by RF Plasma Molecular Beam Epitaxy

    E-Print Network [OSTI]

    on sapphire substrate [2]. Park et al. performed the growth of Cr doped GaN single crystal by sodium fluxScanning Tunneling Microscopy Study of Cr-doped GaN Surface Grown by RF Plasma Molecular Beam Orleans, New Orleans, LA 70148, USA Abstract: Cr doped GaN was grown by rf N-plasma molecular beam epitaxy

  3. Scanning Tunneling Microscopy Study of Cr-doped GaN Surface Grown by RF Plasma Molecular Beam Epitaxy

    E-Print Network [OSTI]

    doped MOCVD grown GaN on sapphire substrate [2]. Park et al. performed the growth of Cr doped GaN singleScanning Tunneling Microscopy Study of Cr-doped GaN Surface Grown by RF Plasma Molecular Beam Orleans, New Orleans, LA 70148, USA Abstract: Cr doped GaN was grown by rf N-plasma molecular beam epitaxy

  4. 2012 IEEE 30th VLSI Test Symposium (VTS) Towards a Fully Stand-Alone Analog/RF BIST: A

    E-Print Network [OSTI]

    Makris, Yiorgos

    -effective analog/RF BIST solution must rely on low-cost measurements obtained through on-chip sensors, along to achieve a fully stand-alone analog/RF BIST solution that can be used for low-cost production test as well in the low-cost measure- ment multi-dimensional space. To investigate this approach, we have designed

  5. Simulation results of an inductively-coupled rf plasma torch in two and three dimensions for producing a metal matrix composite for nuclear fuel cladding

    E-Print Network [OSTI]

    Holik III, Eddie Frank (Trey)

    2009-05-15T23:59:59.000Z

    I propose to develop a new method for the synthesis of metal matrix composites (MMC) using aerosol reactants in a radio frequency (RF) plasma torch. An inductivelycoupled RF plasma torch (ICPT) may potentially be designed to maintain laminar flow...

  6. 2004 URSI Meeting, 5-8 January 2004, at the University of Colorado, Boulder, Colorado, USA. Polyimide Planarization for RF-MEMS Switch on PCB

    E-Print Network [OSTI]

    De Flaviis, Franco

    Polyimide Planarization for RF-MEMS Switch on PCB Bahram Ghodsian, C. Jung, B. Cetiner and F. De Flaviis it maintains the high RF-performance of switches. The fabrication process uses polyimide to planerize

  7. Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging

    DOE Patents [OSTI]

    Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

    1984-01-01T23:59:59.000Z

    An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

  8. Oxygen isotope content of CO2 in nocturnal ecosystem respiration: 2. Short-term dynamics of foliar and soil component fluxes in an

    E-Print Network [OSTI]

    Ehleringer, Jim

    Oxygen isotope content of CO2 in nocturnal ecosystem respiration: 2. Short-term dynamics of foliar; accepted 29 October 2003; published 23 December 2003. [1] The oxygen isotope contents (d18 O) of soil showed enrichment over a 2-week sampling period as the weather became hot and dry (leaves 0.9 to 15

  9. The Fractional London Equation and The Fractional Pippard Model For Superconductors

    E-Print Network [OSTI]

    José Weberszpil

    2012-07-23T23:59:59.000Z

    With the discovery of new superconductors there was a running to find the justifications for the new properties found in these materials. In order to describe these new effects some theories were adapted and some others have been tried. In this work we present an application of the fractional calculus to study the superconductor in the context of London theory. Here we investigated the linear London equation modified by fractional derivatives for non-differentiable functions, instead of integer ones, in a coarse grained scenario. We apply the fractional approach based in the modified Riemann-Liouville sense to improve the model in order to include possible non-local interactions and the media. It is argued that the e ects of non-locality and long memory, intrinsic to the formalism of the fractional calculus, are relevant to achieving a satisfactory phenomenological description. In order to compare the present results with the usual London theory, we calculated the magnetic field distribution for a mesoscopic superconductor system. Also, a fractional Pippard-like model is proposed to take into account the non-locality beside effects of interactions and the media. We propose that parameter alfa of fractionality can be used to create an alternative way to characterize superconductors.

  10. Tunable fractional-order Fourier transformer

    SciTech Connect (OSTI)

    Malyutin, A A [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2006-01-31T23:59:59.000Z

    A fractional two-dimensional Fourier transformer whose orders are tuned by means of optical quadrupoles is described. It is shown that in the optical scheme considered, the Fourier-transform order a element of [0,1] in one of the mutually orthogonal planes corresponds to the transform order (2-a) in another plane, i.e., to inversion and inverse Fourier transform of the order a. (laser modes and beams)

  11. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Martinec, Emil J

    2015-01-01T23:59:59.000Z

    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  12. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Emil J. Martinec

    2015-05-20T23:59:59.000Z

    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  13. Chiral anomaly, bosonization, and fractional charge

    SciTech Connect (OSTI)

    Mignaco, J.A.; Monteiro, M.A.R.

    1985-06-15T23:59:59.000Z

    We present a method to evaluate the Jacobian of chiral rotations, regulating determinants through the proper-time method and using Seeley's asymptotic expansion. With this method we compute easily the chiral anomaly for ..nu.. = 4,6 dimensions, discuss bosonization of some massless two-dimensional models, and handle the problem of charge fractionization. In addition, we comment on the general validity of Fujikawa's approach to regulate the Jacobian of chiral rotations with non-Hermitian operators.

  14. Fractional Quantum Hall States in Graphene

    E-Print Network [OSTI]

    Ahmed Jellal; Bellati Malika

    2011-04-27T23:59:59.000Z

    We quantum mechanically analyze the fractional quantum Hall effect in graphene. This will be done by building the corresponding states in terms of a potential governing the interactions and discussing other issues. More precisely, we consider a system of particles in the presence of an external magnetic field and take into account of a specific interaction that captures the basic features of the Laughlin series \

  15. Development of plutonium aerosol fractionation system

    E-Print Network [OSTI]

    Mekala, Malla R.

    1993-01-01T23:59:59.000Z

    microns), inhalation accidents occurring during maintenance operations can be expected to result in long term retention of 20% to 30% of the inhaled aerosol. Thind"' performed experiments over a span of one year to observe the consistency...DEVELOPMENT OF A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August...

  16. Use of a directional spray system design to control respirable dust and free gas concentrations around a continuous mining machine

    SciTech Connect (OSTI)

    Goodman, G.V.R.; Pollock, D.E. [NIOSH, Pittsburgh, PA (US). Pittsburgh Research Lab.

    2004-12-15T23:59:59.000Z

    A laboratory study assessed the impacts of water spray pressure, face ventilation quantity, and line brattice setback distance on respirable dust and SF6 tracer gas concentrations around a continuous mining machine using a sprayfan or directional spray system. Dust levels were measured at locations representing the mining machine operator and the standard and off standard shuttle car operators, and in the return airway. The results showed that changes in all three independent variables significantly affected log-transformed dust levels at the three operator sampling locations. Changes in setback distance impacted return airway dust levels. Laboratory testing also identified numerous variable interactions affecting dust levels. Tracer gas levels were measured on the left and right sides of the cutting drum and in the return. Untransformed gas levels around the cutting drum were significantly affected by changes in water pressure, face ventilation quantity, and setback distance. Return gas levels measured at the low curtain quantity were generally unaffected by changes in water pressure or curtain setback distance. At the high curtain quantity, return airway gas levels were affected by curtain setback distance. A field study was conducted to assess the impact of these parameters in an actual mining operation. These data showed that respirable dust levels may have been impacted by a change in water pressure and, to a lesser extent, by an increase in curtain setback distance. A series of tracer gas pulse tests were also conducted during this study. The results showed that effectiveness of the face ventilation was impacted by changes in curtain flow quantity and setback distance.

  17. Aspect Ratio Dependence of Bootstrap Current and RF Current Driving Efficiency

    E-Print Network [OSTI]

    Boyer, Edmond

    . Ashidaa a National Institute of advanced Industrial Science and Technology, Tsukuba, Japan, b Nihon University, Institute of Quantum Science, Tokyo, Japan, c Nihon University, College of Industrial Technology pinch (RFP) with the low aspect ratio of A = 2.0, then significantly reduces the rf-driven current

  18. PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC

    E-Print Network [OSTI]

    PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC S. SchreiberÂŁ for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract The TESLA Test Facility Linac (TTFL) at DESY uses two modules with 8 TESLA superconducting accelerat- ing structures each to accelerate an electron

  19. FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC

    E-Print Network [OSTI]

    FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC S. Schreiber for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract During 1997 and 1998 a first accelerator module was tested successfully at the TESLA Test Facility Linac (TTFL) at DESY. Eight superconducting

  20. Robust Linearization of RF Amplifiers Using NonLinear Internal Model Control Method

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Robust Linearization of RF Amplifiers Using NonLinear Internal Model Control Method Smail Bachir #1, the nonlinear Internal Model Control (IMC) method is introduced and applied to linearize high frequency Power to be controlled [8]. If the model is a perfect representation of the non linear system, the controller can

  1. IEEE ELECTRON DEVICE LETTERS, VOL. 24, NO. 4, APRIL 2003 227 RF MEMS Switches Fabricated on

    E-Print Network [OSTI]

    Cetiner, Bedri A.

    with superior performance over con- ventional semiconductor devices [4]­[7]. Typically, RF MEMS switches-resistivity silicon wafers, gallium arsenide (GaAs) wafers, and quartz substrates using semiconductor Manuscript and surface planarization of wide metal lines prior to deposition of a metal membrane bridge, which poses

  2. EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN SL/98-060 (RF)

    E-Print Network [OSTI]

    Keil, Eberhard

    EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN SL/98-060 (RF) A Recirculating Electron Accelerator will become available after the decommissioning of LEP. The major design features and subjects of further developments are discussed. Geneva, Switzerland October 9, 1998 #12;1 INTRODUCTION The European nuclear physics

  3. ACP-OPLL Photonic Integrated Circuits for High Dynamic Range RF/Photonic links

    E-Print Network [OSTI]

    Coldren, Larry A.

    the local optical phase modulators Laser source RF input ACP-OPLL Phase modulator PD PD Output PhaseB optical coupler and a feedback trace from the photodetector common electrode to the phase modulator common electrode. Through phase tracking the OPLL forces the optical phase of the local ACP phase modulator

  4. A Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source

    E-Print Network [OSTI]

    -cathode is closed only by the ion current to the cathode chamber wall. The extraction of electrons from the rf through this opening is larger than the ion saturation current to the chamber wall, then the maximum by the plasma density in the cathode chamber, the ion Bohm velocity at the sheath edge and the surface area

  5. WTJ(S^rf7?\\ Ris-R-761p*

    E-Print Network [OSTI]

    WTJ(S^rf7?\\ Risř-R-761Łp*Thermonuclear Fusion September 1994 #12;ANNUAL PROGRESS _****ig*r REPORT 1993 Work in Controlled Thermonuclear Fusion Research Research Performed in The Fusion Research Unit underthe Contract ofAssociationbetween Euratom and Risř

  6. Development of a 1319-nm Laser Radar Using Fiber Optics and RF Pulse Compression

    E-Print Network [OSTI]

    Kansas, University of

    Development of a 1319-nm Laser Radar Using Fiber Optics and RF Pulse Compression Christopher T of this concept. Our laboratory breadboard uses standard, single-mode optical fiber, off-the-shelf fiber-optic IMPLEMENTATION 3.1 Transmitter--Single-mode laser 3.2 Transmitter--Single-mode fiber 3.3 Transmitter--Optical

  7. Modeling and identification of continuous-time system for RF amplifiers

    E-Print Network [OSTI]

    Boyer, Edmond

    Modeling and identification of continuous-time system for RF amplifiers Mourad Djamai 1 , Smail present a new identification proce- dure for radio frequency Power Amplifier (PA) in the presence signals in time domain. I. INTRODUCTION Numerous approaches in Power Amplifier identification area have

  8. New low-level rf system for the Fermilab Booster synchrotron

    SciTech Connect (OSTI)

    Kerns, C.; Crisp, J.; Kerns, Q.; Miller, H.

    1987-03-01T23:59:59.000Z

    This paper describes the Booster low-level rf system that was constructed to meet these recently added requirements: (1) synthesizer controlled capture frequency at injection, (2) very low-phase noise over the machine cycle, (3) smooth phase-lock of beam to an external reference frequency and (4) ability to accelerate either a full turn or partial turn of beam.

  9. Optical Investigations of Dust Particles Distribution in RF and DC Discharges

    SciTech Connect (OSTI)

    Ramazanov, T. S.; Dosbolayev, M. K.; Jumabekov, A. N.; Amangaliyeva, R. Zh. [Al-Farabi Kazakh National University, IETP, 96a Tole Bi St., Almaty 050012 (Kazakhstan); Filatova, I. I.; Azharonok, V. V. [B. I. Stepanov Institute of Physics NAS of Belarus, Nezavisimosti Ave., 68, 220072, Minsk (Belarus)

    2008-09-07T23:59:59.000Z

    Optical emission spectroscopy is used to study dust particles movement and conditions of a formation of ordered plasma-dust structures in a capacitively coupled RF discharge. 3D binocular diagnostics of plasma-dust structures in dc discharge was made.

  10. Recombination time of an RF discharge plasma in the presence of water molecules

    SciTech Connect (OSTI)

    Protasevich, E.T.

    1986-05-01T23:59:59.000Z

    The authors show that the introduction of water vapor into an electrodeless rf discharge noticeably reduces the excitation temperature and substantially increases the recombination time of the plasma. An attempt is made to explain the physical processes associated with these phenomena.

  11. CRYOGENIC TESTING OF THE RF INPUT WAVEGUIDE FOR THE CEBAF UPGRADE CRYOMODULE*

    E-Print Network [OSTI]

    CRYOGENIC TESTING OF THE RF INPUT WAVEGUIDE FOR THE CEBAF UPGRADE CRYOMODULE* T. Hiatt , M. Breth to support the planned CEBAF upgrade at the Jefferson Lab a new cryomodule has been designed. A key component original CEBAF waveguides. A series of tests were performed on the waveguide to include temperature

  12. A low RF-band impedance spectroscopy based sensor for in-situ, wireless soil sensing

    E-Print Network [OSTI]

    Kumar, Ratnesh

    1 A low RF-band impedance spectroscopy based sensor for in-situ, wireless soil sensing Gunjan of impedance spectroscopy. Impedance measurement at multiple frequencies is done by comparing the amplitude impedance of the board in the measurements to minimize the errors. Measurements of both real and imaginary

  13. TITANIUM NITRIDE COATING AS A MULTIPACTOR SUPPRESSOR ON RF COUPLER CERAMIC WINDOWS*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    TITANIUM NITRIDE COATING AS A MULTIPACTOR SUPPRESSOR ON RF COUPLER CERAMIC WINDOWS* W. Kaabi# , H. The obtained measurements point out how the Nitrogen vacancy on the film can be controlled very well acting a low Secondary Electron Emission Yield (SEY). Titanium Nitride is a good candidate for this purpose

  14. NPN RF Transistor This device is designed for use in low noise UHF/VHF amplifiers

    E-Print Network [OSTI]

    Berns, Hans-Gerd

    NPN RF Transistor This device is designed for use in low noise UHF/VHF amplifiers with collector currents in the 100 µA to 30 mA range in common emitter or common base mode of operation, and in low degrees C. 2) These are steady state limits. The factory should be consulted on applications involving

  15. Analog/RF Design Techniques for High Performance Nanoelectronic On-Chip Interconnects

    E-Print Network [OSTI]

    Liu, Bao

    explores this possibility, espe- cially, application of two analog/RF design techniques as fol- low. 1- mance nanoelectronic on-chip interconnects: (1) application of distributed amplifiers for signal. Application of distributed amplifiers for signal attenua- tion reduction in high performance nanoelectronic on

  16. Structure and magnetic properties of rf thermally plasma synthesized Mn and MnZn ferrite nanoparticles

    E-Print Network [OSTI]

    McHenry, Michael E.

    Structure and magnetic properties of rf thermally plasma synthesized Mn and Mn­Zn ferrite has previously been shown to be a viable route to producing nanocrystalline magnetite and Ni ferrite nanoparticles. In this work nanocrystalline powders of Mn and Mn­Zn ferrites have been synthesized using a 50 k

  17. Synthesis of Nickel-Zinc Ferrites in RF Thermal Plasma Reactor J. Szpvlgyi1,2*

    E-Print Network [OSTI]

    Gubicza, Jenő

    Synthesis of Nickel-Zinc Ferrites in RF Thermal Plasma Reactor J. Szépvölgyi1,2* , I. Mohai1 , L POB 32, Budapest, Hungary Abstract Nickel-zinc ferrites usually exhibit high saturation mag. In this paper results of thermal plasma synthesis of nanosized nickel-zinc ferrites from oxide powders

  18. Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap

    E-Print Network [OSTI]

    Zhu, Feng

    2012-02-14T23:59:59.000Z

    A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

  19. RF and Surface Properties of Bulk Niobium and Niobium Film Samples

    E-Print Network [OSTI]

    Junginger, Tobias; Weingarten, Wolfgang

    2012-01-01T23:59:59.000Z

    At CERN a compact Quadrupole Resonator has been developed for the RF characterization of superconducting samples at different frequencies. In this contribution measurements on bulk niobium and niobium ?lm on copper samples are presented. Surface resistance results are being correlated to surface analyses measurements carried out on the same samples.

  20. RF PULSED TESTS ON 3GHZ NIOBIUM CAVITIES J. Le Duff, C. Thomas

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    RF PULSED TESTS ON 3GHZ NIOBIUM CAVITIES J. Le Duff, C. Thomas , G. Bienvenu, H.Sun LAL, Orsay limits have been pushed back thanks to improvements of niobium purity, cavity preparation, as- sembling mT or 50MV/m accelerating field Eacc for TESLA shape bulk niobium (Nb) cavities at T = 0 K

  1. Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01T23:59:59.000Z

    . The channel numbers were marked out on modules A and B. The RF input jack was connected to the input of the power splitter. Eight coaxial cables of increasing length were used to connect the power splitter outputs to the inputs of the attenuator...

  2. Parasitic Characterization of RadioFrequency (RF) Circuits Using MixedMode Simulation

    E-Print Network [OSTI]

    Dutton, Robert W.

    . Introduction For monolithic microwave and RF integrated cir­ cuit applications, accurate modeling of parasitic can vary depending upon the fitting method and the start­ ing guess. In the case of analytical parameter fit­ ting, additional test structures are usually required to consider de­embedding the S

  3. Phase loop bandwidth measurements on the advanced photon source 352 MHz rf systems

    SciTech Connect (OSTI)

    Horan, D.; Nassiri, A.; Schwartz, C.

    1997-08-01T23:59:59.000Z

    Phase loop bandwidth tests were performed on the Advanced Photon Source storage ring 352-MHz rf systems. These measurements were made using the HP3563A Control Systems Analyzer, with the rf systems running at 30 kilowatts into each of the storage ring cavities, without stored beam. An electronic phase shifter was used to inject approximately 14 degrees of stimulated phase shift into the low-level rf system, which produced measureable response voltage in the feedback loops without upsetting normal rf system operation. With the PID (proportional-integral-differential) amplifier settings at the values used during accelerator operation, the measurement data revealed that the 3-dB response for the cavity sum and klystron power-phase loops is approximately 7 kHz and 45 kHz, respectively, with the cavities the primary bandwidth-limiting factor in the cavity-sum loop. Data were taken at various PID settings until the loops became unstable. Crosstalk between the two phase loops was measured.

  4. A 60GHz, 13dBm Fully Integrated 65nm RF-CMOS Power Amplifier

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    simulation. A. Transistor Layout Caracterisation The size of the transistor depends on the maximum powerA 60GHz, 13dBm Fully Integrated 65nm RF-CMOS Power Amplifier Sofiane Aloui, Eric Kerhervé IMS-CNRS University of Toulouse Toulouse, France plana@laas.fr Abstract--A 65nm CMOS, 60GHz fully integrated power

  5. Heterogeneous PLC-RF networking for LLNs Cdric Chauvenet*,** --Bernard Tourancheau*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Heterogeneous PLC-RF networking for LLNs CĂ©dric Chauvenet*,** -- Bernard Tourancheau* * CITI INSA and city automation, our view of the future building networking infrastructure places PLC as the central point. Thanks to the design of converging IPv6 networking layers, we show that merging PLC with existing

  6. A multichannel, real-time MRI RF power monitor for independent SAR determination

    SciTech Connect (OSTI)

    El-Sharkawy, AbdEl-Monem M.; Qian Di; Bottomley, Paul A.; Edelstein, William A. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States) and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States)

    2012-05-15T23:59:59.000Z

    Purpose: Accurate measurements of the RF power delivered during clinical MRI are essential for safety and regulatory compliance, avoiding inappropriate restrictions on clinical MRI sequences, and for testing the MRI safety of peripheral and interventional devices at known RF exposure levels. The goal is to make independent RF power measurements to test the accuracy of scanner-reported specific absorption rate (SAR) over the extraordinary range of operating conditions routinely encountered in MRI. Methods: A six channel, high dynamic range, real-time power profiling system was designed and built for monitoring power delivery during MRI up to 440 MHz. The system was calibrated and used in two 3 T scanners to measure power applied to human subjects during MRI scans. The results were compared with the scanner-reported SAR. Results: The new power measurement system has highly linear performance over a 90 dB dynamic range and a wide range of MRI duty cycles. It has about 0.1 dB insertion loss that does not interfere with scanner operation. The measurements of whole-body SAR in volunteers showed that scanner-reported SAR was significantly overestimated by up to about 2.2 fold. Conclusions: The new power monitor system can accurately and independently measure RF power deposition over the wide range of conditions routinely encountered during MRI. Scanner-reported SAR values are not appropriate for setting exposure limits during device or pulse sequence testing.

  7. Ion transport in macroscopic RF linear traps Jofre Pedregosa-Gutierrez,

    E-Print Network [OSTI]

    Boyer, Edmond

    ´er^ome, 13397 Marseille Cedex 20, France (Dated: July 18, 2014) Abstract Efficient transport of cold atomsIon transport in macroscopic RF linear traps Jofre Pedregosa-Gutierrez, Caroline Champenois, Marius information processing to frequency metrology. Different transport schemes have been developed, which allow

  8. Development of fundamental power coupler for high-current superconducting RF cavity

    SciTech Connect (OSTI)

    Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

    2012-05-20T23:59:59.000Z

    Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.

  9. Observation of Liquid Metal Actuation in Microfluidic Channels and Implementation to Tunable RF Inductors 

    E-Print Network [OSTI]

    Dogan, Yusuf

    2014-07-18T23:59:59.000Z

    with an expected speed is achieved. At the end of the study, tunability in an RF inductor using liquid metal as a switching part is provided, once a solution to the nagging oxidation problem of liquid metals is offered, and thus the feasibility of liquid metals...

  10. Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap 

    E-Print Network [OSTI]

    Zhu, Feng

    2012-02-14T23:59:59.000Z

    A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

  11. Laser cooling and sympathetic cooling in a linear quadrupole rf trap 

    E-Print Network [OSTI]

    Ryjkov, Vladimir Leonidovich

    2005-02-17T23:59:59.000Z

    An investigation of the sympathetic cooling method for the studies of large ultra-cold molecular ions in a quadrupole ion trap has been conducted.Molecular dynamics simulations are performed to study the rf heating mechanisms in the ion trap...

  12. Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control

    E-Print Network [OSTI]

    Tentzeris, Manos

    shortage risk. (2) Adaptive optimal operation point tracking considering harvested energy variability. (3Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control Ryo-- In this paper, we present a software control method that maximizes the sensing rate of wireless sensor networks

  13. A Wireless Sensing Platform Utilizing Ambient RF Energy Aaron N. Parks 1

    E-Print Network [OSTI]

    Hochberg, Michael

    to store as much energy. When the requirement for on-board energy storage decreases, a smaller (longer the minimal energy storage needed for the RF harvesting sensor node to operate. A modern RFID tag, which in urban environments (cellular BTS). Antenna Matching & Charge pump System Controller (TI MSP430) 2.4GHz

  14. TESLA Report 2004-02 Anti-multipactor TiN coating of RF power

    E-Print Network [OSTI]

    N layers generation on surfaces which were not protected in this way previously. Thin TiN films on ceramicTESLA Report 2004-02 1 Anti-multipactor TiN coating of RF power coupler components for TESLA performance of couplers) J. Lorkiewicz1 , The Andrzej Soltan Institute for Nuclear Studies, Pl 05-400 Otwock

  15. Low-frequency RF Coupling To Unconventional (Fat Unbalanced) Dipoles

    SciTech Connect (OSTI)

    Ong, M M; Brown, C G; Perkins, M P; Speer, R D; Javedani, J B

    2010-12-07T23:59:59.000Z

    The report explains radio frequency (RF) coupling to unconventional dipole antennas. Normal dipoles have thin equal length arms that operate at maximum efficiency around resonance frequencies. In some applications like high-explosive (HE) safety analysis, structures similar to dipoles with ''fat'' unequal length arms must be evaluated for indirect-lightning effects. An example is shown where a metal drum-shaped container with HE forms one arm and the detonator cable acts as the other. Even if the HE is in a facility converted into a ''Faraday cage'', a lightning strike to the facility could still produce electric fields inside. The detonator cable concentrates the electric field and carries the energy into the detonator, potentially creating a hazard. This electromagnetic (EM) field coupling of lightning energy is the indirect effect of a lightning strike. In practice, ''Faraday cages'' are formed by the rebar of the concrete facilities. The individual rebar rods in the roof, walls and floor are normally electrically connected because of the construction technique of using metal wire to tie the pieces together. There are two additional requirements for a good cage. (1) The roof-wall joint and the wall-floor joint must be electrically attached. (2) All metallic penetrations into the facility must also be electrically connected to the rebar. In this report, it is assumed that these conditions have been met, and there is no arcing in the facility structure. Many types of detonators have metal ''cups'' that contain the explosives and thin electrical initiating wires, called bridge wires mounted between two pins. The pins are connected to the detonator cable. The area of concern is between the pins supporting the bridge wire and the metal cup forming the outside of the detonator. Detonator cables usually have two wires, and in this example, both wires generated the same voltage at the detonator bridge wire. This is called the common-mode voltage. The explosive component inside a detonator is relatively sensitive, and any electrical arc is a concern. In a safety analysis, the pin-to-cup voltage, i.e., detonator voltage, must be calculated to decide if an arc will form. If the electric field is known, the voltage between any two points is simply the integral of the field along a line between the points. Eq. 1.1. For simplicity, it is assumed that the electric field and dipole elements are aligned. Calculating the induced detonator voltage is more complex because of the field concentration caused by metal components. If the detonator cup is not electrically connected to the metal HE container, the portion of the voltage generated by the dipole at the detonator will divide between the container-to-cup and cup-to-pin gaps. The gap voltages are determined by their capacitances. As a simplification, it will be assumed the cup is electrically attached, short circuited, to the HE container. The electrical field in the pin-to-cup area is determined by the field near the dipole, the length of the dipole, the shape of the arms, and the orientation of the arms. Given the characteristics of a lightning strike and the inductance of the facility, the electric fields in the ''Faraday cage'' can be calculated. The important parameters for determining the voltage in an empty facility are the inductance of the rebars and the rate of change of the current, Eq. 1.3. The internal electric fields are directly related to the facility voltages, however, the electric fields in the pin-to-cup space is much higher than the facility fields because the antenna will concentrate the fields covered by the arms. Because the lightning current rise-time is different for every strike, the maximum electric field and the induced detonator voltage should be described by probability distributions. For pedantic purposes, the peak field in the simulations will be simply set to 1 V/m. Lightning induced detonator voltages can be calculated by scaling up with the facility fields. Any metal object around the explosives, such as a work stand, will also distort the electric

  16. Predictions of VRF on a Langmuir Probe under the RF Heating Spiral on the Divertor Floor on NSTX-U

    SciTech Connect (OSTI)

    Hosea, J C [PPPL; Perkins, R J [PPPL; Jaworski, M A [PPPL; Kramer, G J [PPPL; Ahn, J-W [ORNL

    2014-07-01T23:59:59.000Z

    RF heating deposition spirals are observed on the divertor plates on NSTX as shown in for a NB plus RF heating case. It has been shown that the RF spiral is tracked quite well by the spiral mapping of the strike points on the divertor plate of magnetic field lines passing in front of the high harmonic fast wave (HHFW) antenna on NSTX. Indeed, both current instrumented tiles and Langmuir probes respond to the spiral when it is positioned over them. In particular, a positive increment in tile current (collection of electrons) is obtained when the spiral is over the tile. This current can be due to RF rectification and/or RF heating of the scrape off layer (SOL) plasma along the magnetic field lines passing in front of the the HHFW antenna. It is important to determine quantitatively the relative contributions of these processes. Here we explore the properties of the characteristics of probes on the lower divertor plate to determine the likelyhood that the primary cause of the RF heat deposition is RF rectification.

  17. Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui

    E-Print Network [OSTI]

    Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui Sitindra S studied the controls on the fractionation of hydrogen isotopes during lipid biosynthesis by Haloarcula marismortui, a halophilic archaea, in pure culture experiments by varying organic substrate, the hydrogen

  18. Wavelet Packets of fractional Brownian motion: Asymptotic Analysis and Spectrum

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Wavelet Packets of fractional Brownian motion: Asymptotic Analysis and Spectrum Estimation properties of the autocorrelation functions of the wavelet packet coefficients of a fractional Brownian process. The analysis concerns some families of wavelet paraunitary filters that converge almost

  19. E-model for Transportation Problem of Linear Stochastic Fractional ...

    E-Print Network [OSTI]

    Dr.V.Charles

    2007-03-07T23:59:59.000Z

    Abstract: This paper deals with the so-called transportation problem of linear stochastic fractional programming, and ... sophisticated analysis. Stochastic ... circuit board of multi-objective LSFP, algorithm to identify redundant fractional objective ...

  20. Quarter-Fraction Factorial Designs Constructed via Quaternary Codes

    E-Print Network [OSTI]

    Phoa, Frederick; Xu, Hongquan

    2008-01-01T23:59:59.000Z

    J. S. (1961). The 2 k?p fractional factorial designs. Tech-2, k 2 = 4k and R(D) = 4k while the second choice leads to QUARTER-FRACTION FACTORIAL DESIGNS

  1. Quarter-Fraction Factorial Designs Constructed via Quaternary Codes

    E-Print Network [OSTI]

    Frederick Phoa; Hongquan Xu

    2011-01-01T23:59:59.000Z

    J. S. (1961). The 2 k?p fractional factorial designs. Tech-2, k 2 = 4k and R(D) = 4k while the second choice leads to QUARTER-FRACTION FACTORIAL DESIGNS

  2. Fractional revivals through Rényi uncertainty relations

    E-Print Network [OSTI]

    Elvira Romera; Francisco de los Santos

    2014-09-19T23:59:59.000Z

    We show that the R\\'enyi uncertainty relations give a good description of the dynamical behavior of wave packets and constitute a sound approach to revival phenomena by analyzing three model systems: the simple harmonic oscillator, the infinite square well, and the quantum bouncer. We prove the usefulness of entropic uncertainty relations as a tool for identifying fractional revivals by providing a comparison in different contexts with the usual Heisenberg uncertainty relation and with the common approach in terms of the autocorrelation function.

  3. Hydrolysis and fractionation of lignocellulosic biomass

    DOE Patents [OSTI]

    Torget, Robert W. (Littleton, CO); Padukone, Nandan (Denver, CO); Hatzis, Christos (Denver, CO); Wyman, Charles E. (Lakewood, CO)

    2000-01-01T23:59:59.000Z

    A multi-function process is described for the hydrolysis and fractionation of lignocellulosic biomass to separate hemicellulosic sugars from other biomass components such as extractives and proteins; a portion of the solubilized lignin; cellulose; glucose derived from cellulose; and insoluble lignin from said biomass comprising one or more of the following: optionally, as function 1, introducing a dilute acid of pH 1.0-5.0 into a continual shrinking bed reactor containing a lignocellulosic biomass material at a temperature of about 94 to about 160.degree. C. for a period of about 10 to about 120 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of extractives, lignin, and protein by keeping the solid to liquid ratio constant throughout the solubilization process; as function 2, introducing a dilute acid of pH 1.0-5.0, either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing either fresh biomass or the partially fractionated lignocellulosic biomass material from function 1 at a temperature of about 94-220.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of hemicellulosic sugars, semisoluble sugars and other compounds, and amorphous glucans by keeping the solid to liquid ratio constant throughout the solubilization process; as function 3, optionally, introducing a dilute acid of pH 1.0-5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 2 at a temperature of about 180-280.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process; and as function 4, optionally, introducing a dilute acid of pH 1.0-5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 3 at a temperature of about 180-280.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process.

  4. Polyfunctional catalyst for processiing benzene fractions

    SciTech Connect (OSTI)

    G. Byakov; B.D. Zubitskii; B.G. Tryasunov; I.Ya. Petrov [Kuznetsk Basin State Technical University, Kemerovo (Russian Federation)

    2009-05-15T23:59:59.000Z

    A by-product of the coke industry is a raw benzene fraction benzene- 1 which may serve as for catalytic processes. The paper reports a study on the influence of the composition and temperatures on the activity and selectivity of NiO-V{sub 2}O{sub 6}-MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} catalysts and the corresponding binary and tertiary subsystems are studied by a pulse method in model reactions; the hydrodealkylating of toluene and the hydrodesulfurizing of thioprhene. The optimal catalyst composition is established. The new catalyst is compared with industrial catalysts.

  5. Motility fractionation of bacteria by centrifugation

    E-Print Network [OSTI]

    Claudio Maggi; Alessia Lepore; Jacopo Solari; Alessandro Rizzo; Roberto Di Leonardo

    2013-10-10T23:59:59.000Z

    Centrifugation is a widespread laboratory technique used to separate mixtures into fractions characterized by a specific size, weight or density. We demonstrate that centrifugation can be also used to separate swimming cells having different motility. To do this we study self-propelled bacteria under the influence of an external centrifugal field. Using dynamic image correlation spectroscopy we measure the spatially resolved motility of bacteria after centrifugation. A significant gradient in swimming-speeds is observed for increasing centrifugal speeds. Our results can be reproduced by a model that treats bacteria as "hot" colloidal particles having a diffusion coefficient that depends on the swimming speed.

  6. Optimizing injected solvent fraction in stratified reservoirs 

    E-Print Network [OSTI]

    Moon, Gary Michael

    1993-01-01T23:59:59.000Z

    , . . . 22 4. 2 Water-Oil and Water-Solvent Fractional Flow Curves . . 4. 3 Mobility of Water-Oil-Solvent Mixtures. . . . . . . . 25 5. 1 Injected Solvent Displacing Formation Oil at 0. 5 PVI . . . . 31 5. 2 Comparison of Simulator Results and Buckley...-Levcrctt Analytic Solution at 0. 3 PVI . 5. 3 Comparison of Simulator Results and Walsh-Lake Analytic Solution for Secondary Flood (S, =- S;?= 0. 2) at "Equal Velocity" f?& (f, & ? 0. 35) and 0. 3 PVI?. . . . . . . . . . . . . . . . . 5. 4 Saturation Plot...

  7. Production of stable, non-thermal atmospheric pressure rf capacitive plasmas using gases other than helium or neon

    DOE Patents [OSTI]

    Park, Jaeyoung; Henins, Ivars

    2005-06-21T23:59:59.000Z

    The present invention enables the production of stable, steady state, non-thermal atmospheric pressure rf capacitive .alpha.-mode plasmas using gases other than helium and neon. In particular, the current invention generates and maintains stable, steady-state, non-thermal atmospheric pressure rf .alpha.-mode plasmas using pure argon or argon with reactive gas mixtures, pure oxygen or air. By replacing rare and expensive helium with more readily available gases, this invention makes it more economical to use atmospheric pressure rf .alpha.-mode plasmas for various materials processing applications.

  8. An rf-carpet electrospray ion source to provide isobaric mass calibrants for trans-uranium elements

    E-Print Network [OSTI]

    S. Naimi; S. Nakamura; Y. Ito; H. Mita; K. Okada; A. Ozawa; P. Schury; T. Sonoda; A. Takamine; M. Wada; H. Wollnik

    2012-12-16T23:59:59.000Z

    For trans-uranium elements, stable atomic isobars do not exist. In order to provide isobaric reference ions for the mass measurement of trans-uranium elements, an electrospray ion source (ESI) was combined with an rf-carpet to collect molecular ions efficiently. The rf-carpet allows for simplification of the pumping system to transport ions from the ESI to a precision mass analyzer. Molecular ions appropriate for isobaric references of trans-uranium elements were extracted from the rf-carpet and analyzed by a multi-reflection time-of-flight mass spectrograph (MRTOF-MS) with a resolving power of $\\rm{R_m} \\gtrsim100,000$.

  9. Some Applications of the Fractional Poisson Probability Distribution

    E-Print Network [OSTI]

    Nick Laskin

    2011-11-17T23:59:59.000Z

    Physical and mathematical applications of fractional Poisson probability distribution have been presented. As a physical application, a new family of quantum coherent states has been introduced and studied. As mathematical applications, we have discovered and developed the fractional generalization of Bell polynomials, Bell numbers, and Stirling numbers. Appearance of fractional Bell polynomials is natural if one evaluates the diagonal matrix element of the evolution operator in the basis of newly introduced quantum coherent states. Fractional Stirling numbers of the second kind have been applied to evaluate skewness and kurtosis of the fractional Poisson probability distribution function. A new representation of Bernoulli numbers in terms of fractional Stirling numbers of the second kind has been obtained. A representation of Schlafli polynomials in terms of fractional Stirling numbers of the second kind has been found. A new representations of Mittag-Leffler function involving fractional Bell polynomials and fractional Stirling numbers of the second kind have been discovered. Fractional Stirling numbers of the first kind have been introduced and studied. Two new polynomial sequences associated with fractional Poisson probability distribution have been launched and explored. The relationship between new polynomials and the orthogonal Charlier polynomials has also been investigated. In the limit case when the fractional Poisson probability distribution becomes the Poisson probability distribution, all of the above listed developments and implementations turn into the well-known results of quantum optics, the theory of combinatorial numbers and the theory of orthogonal polynomials of discrete variable.

  10. ORIGINAL ARTICLE Metagenomic analysis of size-fractionated

    E-Print Network [OSTI]

    Stewart, Frank

    and metabolism of OMZ microorganisms vary between particle-associated and free-living size fractions. We used.6 lm) and small (0.2­1.6 lm) filter size fractions along a depth gradient in the OMZ off Chile. Despite steep vertical redox gradients, size fraction was a significantly stronger predictor of community

  11. Deviation probability bounds for fractional martingales and related remarks

    E-Print Network [OSTI]

    Saussereau, Bruno

    2012-01-01T23:59:59.000Z

    In this paper we prove exponential inequalities (also called Bernstein's inequality) for fractional martingales. As an immediate corollary, we will discuss weak law of large numbers for fractional martingales under divergence assumption on the $\\beta-$variation of the fractional martingale. A non trivial example of application of this convergence result is proposed.

  12. An Algorithm for Fractional Assignment Problems Maiko Shigeno

    E-Print Network [OSTI]

    Yamamoto, Hirosuke

    Optimization, Mathematical Programming, Fractional Programming, Assignment Problems, Approximation Optimality fractional assignment problems which are special cases of 0-1 fractional programming problems. Let G = (I; J assignment problem. In this case, the algorithm proposed in this paper solves the linear assignment problem

  13. Electron Spin Precession for the Time Fractional Pauli Equation

    E-Print Network [OSTI]

    Hosein Nasrolahpour

    2011-04-05T23:59:59.000Z

    In this work, we aim to extend the application of the fractional calculus in the realm of quantum mechanics. We present a time fractional Pauli equation containing Caputo fractional derivative. By use of the new equation we study the electron spin precession problem in a homogeneous constant magnetic field.

  14. Neutron Stars Opacity and Proton Fraction

    E-Print Network [OSTI]

    P. N. Alcain; C. O. Dorso

    2015-02-03T23:59:59.000Z

    Background: In neutron stars the nucleons are submitted to extreme conditions. The study of this natural occurring objects can lead to further understanding of the behaviour of nuclear matter in highly asymmetric nuclei. Among the characteristics of neutron stars, its neutrino absorption - associated to structural inhomoegeneities - stands out as one of the possible magnitudes linked to an observable. Purpose: We have carried out a systematic study of this neutrino absorption for different thermodynamic conditions in order to assess the impact that the structure has on it. Method: We study the dynamics of nucleons in conditions according to the neutron star crust with a semiclassical molecular dynamics model, for different densities, proton fractions and temperature, we calculate the long range opacity and the cluster distribution. Results: The neutrino absorption, the main mechanism for neutron stars cooldown, takes its highest value for temperatures and densities low compared with the inner crust, and a proton fraction is close to the symmetric case $x=0.5$. Conclusions: Within the used model the neutrinos are absorbed mostly close to the surface of the neutron star. Also, for high temperatures, a large cluster still exists, but the appearance of several small-sized clusters smears out the very long range order needed for neutrino absorption.

  15. Process for stabilization of coal liquid fractions

    DOE Patents [OSTI]

    Davies, Geoffrey (Boston, MA); El-Toukhy, Ahmed (Alexandria, EG)

    1987-01-01T23:59:59.000Z

    Coal liquid fractions to be used as fuels are stabilized against gum formation and viscosity increases during storage, permitting the fuel to be burned as is, without further expensive treatments to remove gums or gum-forming materials. Stabilization is accomplished by addition of cyclohexanol or other simple inexpensive secondary and tertiary alcohols, secondary and tertiary amines, and ketones to such coal liquids at levels of 5-25% by weight with respect to the coal liquid being treated. Cyclohexanol is a particularly effective and cost-efficient stabilizer. Other stabilizers are isopropanol, diphenylmethanol, tertiary butanol, dipropylamine, triethylamine, diphenylamine, ethylmethylketone, cyclohexanone, methylphenylketone, and benzophenone. Experimental data indicate that stabilization is achieved by breaking hydrogen bonds between phenols in the coal liquid, thereby preventing or retarding oxidative coupling. In addition, it has been found that coal liquid fractions stabilized according to the invention can be mixed with petroleum-derived liquid fuels to produce mixtures in which gum deposition is prevented or reduced relative to similar mixtures not containing stabilizer.

  16. Fractional Calculus in Hydrologic Modeling: A Numerical Perspective

    SciTech Connect (OSTI)

    David A. Benson; Mark M. Meerschaert; Jordan Revielle

    2012-01-01T23:59:59.000Z

    Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.

  17. The effective delayed neutron fraction for bare-metal criticals

    SciTech Connect (OSTI)

    Pearlstein, S.

    1999-12-01T23:59:59.000Z

    Given sufficient material, a large number of actinides could be used to form bare-metal criticals. The effective delayed neutron fraction for a bare critical comprised of a fissile material is comparable with the absolute delayed neutron fraction. The effective delayed neutron fraction for a bare critical composed of a fissionable material is reduced by factors of 2 to 10 when compared with the absolute delayed neutron fraction. When the effective delayed neutron fraction is small, the difference between delayed and prompt criticality is small, and extreme caution must be used in critical assemblies of these materials. This study uses an approximate but realistic model to survey the actinide region to compare effective delayed neutron fractions with absolute delayed neutron fractions.

  18. A new approach to calculate the transport matrix in RF cavities

    SciTech Connect (OSTI)

    Eidelman, Yu.; /Novosibirsk, IYF; Mokhov, N.; Nagaitsev, S.; Solyak, N.; /Fermilab

    2011-03-01T23:59:59.000Z

    A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm will be implemented into the MARS15 code. A realistic approach to calculate the transport matrix in RF cavities is developed. Complete agreement for tracking results with existed code ASTRA is achieved. New algorithm will be implemented into MARS15 code.

  19. Enhancement of RF Breakdown Threshold of Microwave Cavities by Magnetic Insulation

    SciTech Connect (OSTI)

    Stratakis, D.; Gallardo, J.; Palmer, R.B.

    2011-03-28T23:59:59.000Z

    Limitations on the maximum achievable accelerating gradient of microwave cavities can influence the performance, length, and cost of particle accelerators. Gradient limitations are believed to be initiated by electron emission from the cavity surfaces. Here, we show that field emission is effectively suppressed by applying a tangential magnetic field to the cavity walls, so higher gradients can be achieved. Numerical simulations indicate that the magnetic field prevents electrons leaving these surfaces and subsequently picking up energy from the electric field. Our results agree with current experimental data. Two specific examples illustrate the implementation of magnetic insulation into prospective particle accelerator applications. The ultimate goal of several research efforts is to integrate high-gradient radio-frequency (rf) structures into next generation particle accelerators. For instance, the Muon Accelerator Program is looking at developing low-frequency cavities for muon cooling, and the International Linear Collider is optimizing the performance of 1.3 GHz rf structures aimed at designing a 1 TeV electron-positron collider. Furthermore, the High Gradient RF Collaboration is examining high frequency (f > 10 GHz) structures intended for an electron-positron collider operating at energies in the TeV range. In all this research, the accelerating gradient will be one of the crucial parameters affecting their design, construction, and cost. Limitations from rf breakdown strongly influence the development of accelerators since it limits the machine's maximum gradient. The emission of electrons from the cavity surfaces seemingly is a necessary stage in the breakdown process, acting either as a direct cause of breakdown or as precursor for other secondary effects. Typically, electron currents arise from sharp edges or cracks on the cavities surfaces, where the strength of the electric field is strongly enhanced compared to that of the nominal field when the surfaces of the cavity are perfect planes. Subsequently, a stream of emitted electrons can be accelerated by the rf electric field toward the opposing cavity walls. Upon impact, they heat a localized region, resulting in the eventual breakdown by a variety of secondary mechanisms. Therefore, it is advantageous to develop techniques that could suppress field emission within rf cavities. It has been proposed that high voltages up to about a gigavolt range may be sustained in voltage transformers, by adopting the principle of magnetic insulation in ultrahigh vacuum. The basic idea is to suppress field emission by applying a suitably directed magnetic field of sufficient strength to force the electrons orbits back on to the rf emitting surface. More recently, it was shown that magnetic insulation could be very effective in suppressing field emission and multipacting in rectangular coupler waveguides. Hence, the question arises whether the same principle is applicable to rf accelerating structures. In this Letter, we shall consider application of the concept to low-frequency (201-805 MHz) muon accelerator cavities.

  20. Operator interface for the PEP-II low level RF control system

    SciTech Connect (OSTI)

    Allison, S.; Claus, R.

    1997-05-01T23:59:59.000Z

    This paper focuses on the operational aspects of the low level RF control system being built for the PEP-II storage rings at SLAC. Subsystems requiring major operational considerations include displays for monitor and control from UNIX workstations, slow feedback loops and control sequences residing on microprocessors, and various client applications in the existing SLAC Linear Collider (SLC) control system. Since commissioning of PEP-II RF is currently in-progress, only those parts of the control system used during this phase are discussed in detail. Based on past experience with the SLC control system, it is expected that effort expended during commissioning on a solid user interface will result in smoother transition to full reliable 24-hour-a-day operation.

  1. BROADBAND ANTENNA MATCHING NETWORK DESIGN AND APPLICATION FOR RF PLASMA ION SOURCE

    SciTech Connect (OSTI)

    Shin, Ki [ORNL; Kang, Yoon W [ORNL; Piller, Chip [ORNL; Fathy, Aly [University of Tennessee, Knoxville (UTK)

    2011-01-01T23:59:59.000Z

    The RF ion source at Spallation Neutron Source has been upgraded to meet higher beam power requirement. One important subsystem for efficient operation of the ion source is the 2MHz RF impedance matching network. The real part of the antenna impedance is very small and is affected by plasma density for 2MHz operating frequency. Previous impedance matching network for the antenna has limited tuning capability to cover this potential variation of the antenna impedance since it employed a single tuning element and an impedance transformer. A new matching network with two tunable capacitors has been built and tested. This network can allow precision matching and increase the tunable range without using a transformer. A 5-element broadband matching network also has been designed, built and tested. The 5-element network allows wide band matching up to 50 kHz bandwidth from the resonance center of 2 MHz. The design procedure, simulation and test results are presented.

  2. Options for an 11 GeV RF Beam Separator for the Jefferson Lab CEBAF Upgrade

    SciTech Connect (OSTI)

    Jean Delayen, Michael Spata, Haipeng Wang

    2009-05-01T23:59:59.000Z

    The CEBAF accelerator at Jefferson Lab has had, since first demonstration in 1996, the ability to deliver a 5-pass electron beam to experimental halls (A, B, and C) simultaneously. This capability was provided by a set of three, room temperature 499 MHz rf separators in the 5th pass beamline. The separator was two-rod, TEM mode type resonator, which has a high shunt impedance. The maximum rf power to deflect the 6 GeV beams was about 3.4kW. The 12 GeV baseline design does not preserve the capability of separating the 5th pass, 11 GeV beam for the 3 existing halls. Several options for restoring this capability, including extension of the present room temperature system or a new superconducting design in combination with magnetic systems, are under investigation and are presented.

  3. Capture cavity cryomodule for quantum beam experiment at KEK superconducting RF test facility

    SciTech Connect (OSTI)

    Tsuchiya, K.; Hara, K.; Hayano, H.; Kako, E.; Kojima, Y.; Kondo, Y.; Nakai, H.; Noguchi, S.; Ohuchi, N.; Terashima, A. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Horikoshi, A.; Semba, T. [Hitachi, Ltd., Hitachi Works, Hitachi, Ibaraki 317-8511 (Japan)

    2014-01-29T23:59:59.000Z

    A capture cavity cryomodule was fabricated and used in a beam line for quantum beam experiments at the Superconducting RF Test Facility (STF) of the High Energy Accelerator Research Organization in Japan. The cryomodule is about 4 m long and contains two nine-cell cavities. The cross section is almost the same as that of the STF cryomodules that were fabricated to develop superconducting RF cavities for the International Linear Collider. An attempt was made to reduce the large deflection of the helium gas return pipe (GRP) that was observed in the STF cryomodules during cool-down and warm-up. This paper briefly describes the structure and cryogenic performance of the captures cavity cryomodule, and also reports the measured displacement of the GRP and the cavity-containing helium vessels during regular operation.

  4. Beam Profile Measurement in MTA Beam Line for High Pressure RF Cavity Beam Test

    SciTech Connect (OSTI)

    Jana, M.R.; Bross, A.; Chung, M.; Greer, S.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.; Leonova, M.; Moretti, A.; Popovic, M.; Schwartz, T.; /Fermilab /IIT, Chicago /PDT, Torino

    2012-05-15T23:59:59.000Z

    Recent High Pressure RF (HPRF) cavity experiment at MuCool Test Area (MTA) has used 400 MeV Linac proton beam to study the beam loading effect. When the energetic proton beam passes through the cavity, it ionizes the inside gas and produces the electrons. These electrons consume RF power inside the cavity. Number of electrons produced per cm inside the cavity (at 950 psi Hydrogen gas) per incident proton is {approx} 1200. The measurement of beam position and profile are necessary. MTA is flammable gas (Hydrogen) hazard zone so we have developed a passive beam diagnostic instrument using Chromox-6 scintillation screen and CCD camera. This paper presents quantitative information about beam position and beam profile. Neutral density filter was used to avoid saturation of CCD camera. Image data is filtered and fitted with Gaussian function to compute the beam size. The beam profile obtained from scintillation screen shall be compared with multi-wire beam profile.

  5. Tests of an RF Dipole Crabbing Cavity for an Electron-Ion Collider

    SciTech Connect (OSTI)

    Castilla Loeza, Alejandro [ODU, JLAB; Delayen, Jean R. [ODU, JLAB

    2013-12-01T23:59:59.000Z

    On the scheme of developing a medium energy electron-ion collider (MEIC) at Jefferson Lab, we have designed a compact superconducting rf dipole cavity at 750 MHz to crab both electron and ion bunches and increase luminosities at the interaction points (IP) of the machine. Following the design optimization and characterization of the electromagnetic properties such as peak surface fields and shunt impedance, along with field nonuniformities, multipole components content, higher order modes (HOM) and multipacting, a prototype cavity was built by Niowave Inc. The 750 MHz prototype crab cavity has been tested at 4 K and is ready for re-testing at 4 K and 2 K at Jefferson Lab. In this paper we present the detailed results of the rf tests performed on the 750 MHz crab cavity prototype.

  6. Broadband RF Front-End Design for Multi-Standard Receiver with High-Linearity and Low-Noise Techniques

    E-Print Network [OSTI]

    Kim, Ju Sung

    2012-02-14T23:59:59.000Z

    Future wireless communication devices must support multiple standards and features on a single-chip. The trend towards software-defined radio requires flexible and efficient RF building blocks which justifies the adoption of broadband receiver front...

  7. Design of a horizontal test cryostat for superconducting RF cavities for the FREIA facility at Uppsala University

    SciTech Connect (OSTI)

    Chevalier, N. R.; Thermeau, J.-P.; Bujard, P.; Junquera, T. [Accelerators and Cryogenic Systems (ACS), 86 rue de Paris, 91400 Orsay (France); Hermansson, L.; Kern, R. Santiago; Ruber, R. [Uppsala University, Department of Physics and Astronomy, 75120 Uppsala (Sweden)

    2014-01-29T23:59:59.000Z

    Uppsala University is constructing a large scale facility, called FREIA (Facility for Research Instrumentation and Accelerator Development). FREIA includes a helium liquefier and an accelerator test facility and has the capacity to test superconducting radio-frequency (RF) cavities with the same RF system and RF power level as in an accelerator. A central element of FREIA is a horizontal test cryostat connected in closed loop to a helium liquefier. This cryostat can house two fully equipped (tuners, piezo, power coupler, helium tank) superconducting cavities to perform full RF high power tests and operate at temperatures between 1.8 K and 4.2 K. The cryostat is designed to accommodate a large array of superconducting cavities and magnets, among which the European Spallation Source (ESS) type spoke and high-? elliptical cavities as well as TESLA/ILC type elliptical cavities. The present status of the project and the design of the cryostat are reported.

  8. Design methodologies for built-in testing of integrated RF transceivers with the on-chip loopback technique

    E-Print Network [OSTI]

    Onabajo, Marvin Olufemi

    2009-05-15T23:59:59.000Z

    Advances toward increased integration and complexity of radio frequency (RF) andmixed-signal integrated circuits reduce the effectiveness of contemporary testmethodologies and result in a rising cost of testing. The focus in this research...

  9. Anomalous Topological Pumps and Fractional Josephson Effects

    E-Print Network [OSTI]

    Fan Zhang; C. L. Kane

    2013-10-20T23:59:59.000Z

    We discover novel topological pumps in the Josephson effects for superconductors. The phase difference, which is odd under the chiral symmetry defined by the product of time-reversal and particle-hole symmetries, acts as an anomalous adiabatic parameter. These pumping cycles are different from those in the "periodic table", and are characterized by $Z\\times Z$ or $Z_2\\times Z_2$ strong invariants. We determine the general classifications in class AIII, and those in class DIII with a single anomalous parameter. For the $Z_2\\times Z_2$ topological pump in class DIII, one $Z_2$ invariant describes the coincidence of fermion parity and spin pumps whereas the other one reflects the non-Abelian statistics of Majorana Kramers pairs, leading to three distinct fractional Josephson effects.

  10. Topological Current in Fractional Chern Insulators

    E-Print Network [OSTI]

    Koma, Tohru

    2015-01-01T23:59:59.000Z

    We consider interacting fermions in a magnetic field on a two-dimensional lattice with the periodic boundary conditions. In order to measure the Hall current, we apply an electric potential with a compact support. Then, due to the Lorentz force, the Hall current appears along the equipotential line. Introducing a local current operator at the edge of the potential, we derive the Hall conductance as a linear response coefficient. For a wide class of the models, we prove that if there exists a spectral gap above the degenerate ground state, then the Hall conductance of the ground state is fractionally quantized without averaging over the fluxes. This is an extension of the topological argument for the integrally quantized Hall conductance in noninteracting fermion systems on lattices.

  11. Topological Current in Fractional Chern Insulators

    E-Print Network [OSTI]

    Tohru Koma

    2015-04-06T23:59:59.000Z

    We consider interacting fermions in a magnetic field on a two-dimensional lattice with the periodic boundary conditions. In order to measure the Hall current, we apply an electric potential with a compact support. Then, due to the Lorentz force, the Hall current appears along the equipotential line. Introducing a local current operator at the edge of the potential, we derive the Hall conductance as a linear response coefficient. For a wide class of the models, we prove that if there exists a spectral gap above the degenerate ground state, then the Hall conductance of the ground state is fractionally quantized without averaging over the fluxes. This is an extension of the topological argument for the integrally quantized Hall conductance in noninteracting fermion systems on lattices.

  12. Evaluation of the modified Anderson sampler for determining particle size distributions and respirable concentrations of particulate matter present in the working environment of cottonseed oil mills

    E-Print Network [OSTI]

    Matlock, Stanley Wayne

    1976-01-01T23:59:59.000Z

    EVALUATION OF THE MODIFIED ANDERSON SAMPLER FOR DETERMINING PARTICLE SIZE DISTRIBUTIONS AND RESPIRABLE CONCENTRATIONS OF PARTICULATE MATTER PRESENT IN THE WORKING ENVIRONMENT OF COTTONSEED OIL MILLS A Thesis by STANLEY WAYNE MATLOCK Submitted... to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1976 Major Subject: Agricultural Engineering FVALUATION OF THE MODIFIED ANDERSON SAMPLER FOR DETERMINING PARTICLE SIZE...

  13. A PARAMETRIC STUDY OF BCS RF SURFACE IMPEDANCE WITH MAGNETIC FIELD USING THE XIAO CODE

    SciTech Connect (OSTI)

    Reece, Charles E. [JLAB; Xiao, Binping [JLAB, BNL

    2013-09-01T23:59:59.000Z

    A recent new analysis of field-dependent BCS rf surface impedance based on moving Cooper pairs has been presented.[1] Using this analysis coded in Mathematica TM, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the "best theoretical" performance available to potential applications with corresponding materials.

  14. ECR plasma cleaning: an in-situ processing technique for RF cavities

    SciTech Connect (OSTI)

    Wu, G.; /Fermilab; Moeller, W-D.; /DESY; Antoine, C.; /Saclay; Jiang, H.; Pechenezhskiy, I.; Cooley, L.; Khabiboulline, T.; Terechkine, Y.; Edwards, H.; Koeth, T.; Romanenko, A.; /Cornell U., Phys. Dept. /Jefferson Lab

    2008-01-01T23:59:59.000Z

    A condition for Electron Cyclotron Resonance (ECR) can be established inside a fully assembled RF cavity without the need for removing high-power couplers. As such, plasma generated by this process can be used as a final cleaning step, or as an alternative cleaning step in place of other techniques. Tests showed filtered dry air plasma can successfully remove sulfur particles on niobium surface while the surface oxygen content remains intact.

  15. A 900MHz RF Energy Harvesting Module TARIS Thierry, VIGNERAS Valrie

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Abstract --This paper presents a guideline to design and optimize a RF energy harvester operating in ISM-the-shelf devices. The topology of the impedance transformation block is selected to reduce the losses which sensitivity of -22.5 dBm for a dc output voltage of 200 mV up to -11 dBm for 1.08 V. A wireless power

  16. Structure of Velocity Distribution of Sheath-Accelerated Secondary Electrons in Asymmetric RF-DC Discharge

    E-Print Network [OSTI]

    Khrabrov, Alexander V; Ventzek, Peter L G; Ranjan, Alok; Chen, Lee

    2015-01-01T23:59:59.000Z

    The ballistic population is thought to be responsible for alleviating the electron shading effect and the notching of the photoresist layer. We have performed test-particle simulations where the features in the EVDF of electrons impacting the RF electrode are fully resolved at all energies. An analytic model has been developed to predict existence of peaked and step-like structures in the EVDF.

  17. Microphonics detuning compensation in 3.9 GHZ superconducting RF cavities

    SciTech Connect (OSTI)

    Ruben Carcagno et al.

    2003-10-20T23:59:59.000Z

    Mechanical vibrations can detune superconducting radio frequency (SCRF) cavities unless a tuning mechanism counteracting the vibrations is present. Due to their narrow operating bandwidth and demanding mechanical structure, the 13-cell 3.9GHz SCRF cavities for the Charged Kaons at Main Injector (CKM) experiment at Fermilab are especially susceptible to this microphonic phenomena. We present early results correlating RF frequency detuning with cavity vibration measurements for CKM cavities; initial detuning compensation results with piezoelectric actuators are also presented.

  18. TT^T7Gs!rf5ft Riso-R-425 Metallurgy Department

    E-Print Network [OSTI]

    CM tf TT^T7Gs!rf5ft Riso-R-425 (O O o o o \\l O Metallurgy Department Progress Report for the Period-R-425 METALLURGY DEPARTMENT PROGRESS REPORT FOR THE PERIOD 1 JANUARY TO 31 DECEMBER 1979 Abstract. The activities of the Metallurgy Department at Risř during 1979 are described. The work is presented in four chap

  19. High Power Testing of RF Cavities for the PEP II B Factory

    SciTech Connect (OSTI)

    Rimmer, R.A.; /LBL, Berkeley; Allen, M.; Fant, K.; Hill, A.; Hoyt, M.; Judkins, J.; Neubauer, Mark Stephen; Schwarz, H.; /SLAC

    2011-09-01T23:59:59.000Z

    We describe the process of conditioning and high-power testing of RF cavities for PEP-II. Procedures for vacuum assembly, bakeout and automated processing are described. Interlocks and safety precautions for protection of equipment and personnel are discussed and performance data of tested cavity assemblies are reported. Performance of ancillary components such as windows, couplers and tuners is also discussed. Comments are included on handling, alignment, installation and commissioning issues where appropriate.

  20. Heat Equations with Fractional White Noise Potentials

    SciTech Connect (OSTI)

    Hu, Y. [Department of Mathematics, University of Kansas, 405 Snow Hall, Lawrence, KS 66045-2142 (United States)], E-mail: hu@math.ukans.edu

    2001-07-01T23:59:59.000Z

    This paper is concerned with the following stochastic heat equations: ({partial_derivative}u{sub t}(x))/({partial_derivative}t=1/2 u{sub t}(x)+{omega}{sup H}.u{sub t}(x)), x element of {sup d}, t>0, where w{sup H} is a time independent fractional white noise with Hurst parameter H=(h{sub 1}, h{sub 2},..., h{sub d}) , or a time dependent fractional white noise with Hurst parameter H=(h{sub 0}, h{sub 1},..., h{sub d}) . Denote | H | =h{sub 1}+h{sub 2}+...+h{sub d} . When the noise is time independent, it is shown that if 1/2 d-1 , then the solution is in L{sub 2} and the L{sub 2} -Lyapunov exponent of the solution is estimated. When the noise is time dependent, it is shown that if 1/2 d- 2 /( 2h{sub 0}-1 ) , the solution is in L{sub 2} and the L{sub 2} -Lyapunov exponent of the solution is also estimated. A family of distribution spaces S{sub {rho}} , {rho} element of RR , is introduced so that every chaos of an element in S{sub {rho}} is in L{sub 2} . The Lyapunov exponents in S{sub {rho}} of the solution are also estimated.