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Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
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1

Airborne release fraction -ARF- and respirable fraction -RF- for foot pack cans in fires  

SciTech Connect (OSTI)

The purpose of this analysis is to provide the airborne release fraction (ARF), respirable fraction (RF) and respirable release as a fraction of initial mass for Food Pack Cans (FPCs) containing plutonium powders (e.g., oxide) that become pressurized to the point of bursting in a fire.

CARSON, D.M.

2002-06-05T23:59:59.000Z

2

Respiration, photosynthesis, and oxygen isotope fractionation in ...  

Science Journals Connector (OSTI)

Jan 25, 1971 ... Respiration, photosynthesis, and oxygen isotope fractionation in oceanic surface water1. Peter M. Kroopnick. Department of Oceanography,.

2000-01-04T23:59:59.000Z

3

Airborne release fractions/rates and respirable fractions for nonreactor nuclear facilities. Volume 2, Appendices  

SciTech Connect (OSTI)

This document contains compiled data from the DOE Handbook on Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear facilities. Source data and example facilities utilized, such as the Plutonium Recovery Facility, are included.

Not Available

1994-12-01T23:59:59.000Z

4

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

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

TS NOT MEASUREMENT SENSITIVE DOE-HDBK-3010-94 December 1994 Reaffirmed 2013 DOE HANDBOOK AIRBORNE RELEASE FRACTIONS/RATES AND RESPIRABLE FRACTIONS FOR NONREACTOR NUCLEAR FACILITIES Volume II - Appendices U.S. Department of Energy AREA SAFT Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650. Order No. DE95004711 DOE-HDBK-3010-94

5

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

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

TS NOT MEASUREMENT SENSITIVE DOE-HDBK-3010-94 December 1994 Reaffirmed 2013 DOE HANDBOOK AIRBORNE RELEASE FRACTIONS/RATES AND RESPIRABLE FRACTIONS FOR NONREACTOR NUCLEAR FACILITIES Volume I - Analysis of Experimental Data U.S. Department of Energy AREA SAFT Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650.

6

Proposed beryllium metal bounding airborne release fractions (ARFs)/rates (ARRs) and respirable fractions (RFs) for DOE facility accidents analyses  

Science Journals Connector (OSTI)

Beryllium metal has special properties for nuclear applications and is used widely within the Department of Energy (DOE) complex. Beryllium is toxic and has the potential to cause health effects (sensitization and chronic beryllium disease) to workers. Due to the type of processing involving large quantities of beryllium metal and powders and potential for significant airborne release under accident conditions, a comprehensive hazard analysis is required by DOE in a safety analysis document that evaluates potential accidents that can cause beryllium releases to the workplace and public or to the environment. The goal of the safety analysis is to identify and evaluate hazards so that appropriate controls or safeguards can be specified to protect the workers and public from potential accidents. A hazard assessment is also required to comply with 10 CFR Part 850, Chronic Beryllium Disease Prevention Program (1999) to protect the workers. DOE safety analyses include a quantitative estimate of releases and downwind concentrations for purposes of hazard classification and determination of the need for additional hazards analysis, accident analysis, and risk assessments. There are no complex-wide accepted Airborne Release Fractions (ARFs) and Respirable Fractions (RFs) that can be used to evaluate the potential downwind consequences of releases of beryllium under various accident conditions (e.g., spill, fire, stress, explosion, etc.). The purpose is to recommend DOE complex-wide \\{ARFs\\} and \\{RFs\\} that can be used to evaluate the potential downwind consequences of accidents. This paper proposes various values for \\{ARFs\\} and \\{RFs\\} that are based on review of the published information and data on the oxidation and ignition behavior of beryllium metal encased in a thin coat of non-porous, adherent oxide (“blue oxide”); the typical form of this material found in DOE facilities. Information is also presented as a function of the morphology of the metal (i.e., large, coherent, pieces; turnings/swarfs; chips/powder; and dust) because the surface to volume ratio is an important factor in evaluating both the amount of beryllium released and the potential for ignition of the metal that may increase the amount of release significantly. Guidance is also provided for the use of the DOE-HDBK-3010-94, Airborne Release Fractions/Rates and Respirable Fraction for Nonreactor Nuclear Facilities, values for oxide releases that result in a more liberal, allowable limiting airborne concentration for determining consequences and hazard classification of the facility. Detailed explanations of the proposed ARF/RF values for the various beryllium metal forms (large coherent pieces, chips/powder, turning/swarfs from processing, and dust) and other aspects of beryllium are provided in a report by Mishima et al. (April 2005). A short version of this report and a summary of the ARF/RF values are presented here.

Jofu Mishima; Terry L. Foppe; J.C. Laul

2008-01-01T23:59:59.000Z

7

Airborne release fractions/rates and respirable fractions for nonreactor nuclear facilities. Volume 1, Analysis of experimental data  

SciTech Connect (OSTI)

This handbook contains (1) a systematic compilation of airborne release and respirable fraction experimental data for nonreactor nuclear facilities, (2) assessments of the data, and (3) values derived from assessing the data that may be used in safety analyses when the data are applicable. To assist in consistent and effective use of this information, the handbook provides: identification of a consequence determination methodology in which the information can be used; discussion of the applicability of the information and its general technical limits; identification of specific accident phenomena of interest for which the information is applicable; and examples of use of the consequence determination methodology and airborne release and respirable fraction information.

Not Available

1994-12-01T23:59:59.000Z

8

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

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

3010-94 3010-94 December 1994 DOE HANDBOOK AIRBORNE RELEASE FRACTIONS/RATES AND RESPIRABLE FRACTIONS FOR NONREACTOR NUCLEAR FACILITIES Volume II - Appendices U.S. Department of Energy AREA SAFT Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650. Order No. DE95004711 DOE-HDBK-3010-94 Page i VOLUME II: APPENDICES APPENDIX A

9

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

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

10-94 10-94 December 1994 CHANGE NOTICE NO. 1 March 2000 DOE HANDBOOK AIRBORNE RELEASE FRACTIONS/RATES AND RESPIRABLE FRACTIONS FOR NONREACTOR NUCLEAR FACILITIES Volume I - Analysis of Experimental Data U.S. Department of Energy AREA SAFT Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced from the best available copy. Available to DOE and DOE contractors from ES&H Technical Information Services, U.S. Department of Energy, (800) 473-4375, fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 605-6000. Change Notice No. 1 DOE-HDBK-3010-94 March 2000 Airborne Release Fractions/Rates and Respirable Fractions

10

rf  

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

RF RF It's what makes the protons go 'round. The latest in a series explaining particle physics in everyday language. Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

11

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

E-Print Network [OSTI]

Figure IO to show a comparison w1th the ISO 20 100 80 I- Z LLI 60 LLI Q. 0 ~ 40 IX I- LLI z LIJ 0 20 I 2 3 4 5 7 10 AERODYNAMIC PARTICLE DIAMETER, pm Figure 9. Penetration of rronodisperse aerosols through the RSP fractionator. Flow rate... yielded penetration values w1thin one percent of the values observed for the first set of tests. The experimentally observed relationship between cutoo1nt s1ze and flow rate, Figure 11, is one wh1ch provides- reason to question a commonly-used theory...

Rue, Clayton Matthew

2012-06-07T23:59:59.000Z

12

COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS  

SciTech Connect (OSTI)

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.

S.O. Bader

1999-10-18T23:59:59.000Z

13

Rf Feedback free electron laser  

DOE Patents [OSTI]

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.

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

14

Booster Subharmonic RF Capture Design  

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

Booster Subharmonic RF Capture Design 1 Booster Subharmonic RF Capture Design Nicholas S. Sereno, 7102002 1.0 Motivation and Requirements Successful operation of the APS storage...

15

Spectroscopy of Rf257  

Science Journals Connector (OSTI)

The isotope Rf257 was produced in the fusion-evaporation reaction Pb208(Ti50,n)Rf257. Reaction products were separated and identified by mass. Delayed spectroscopy of Rf257 and its decay products was performed. A partial decay scheme with configuration assignments is proposed based on ? hindrance factors. The excitation energy of the 1/2+[620] configuration in No253 is proposed. The energy of this 1/2+ state in a series of N=151 isotones increases with nuclear charge, reflecting an increase in the N=152 gap. This gap is deduced to grow substantially from 850 to 1400 keV between Z=94 and 102. An isomeric state in Rf257, with a half-life of 160-31+42??s, was discovered by detecting internal conversion electrons followed by ? decay. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal conversion electrons, with a half-life of 4.1-1.3+2.4 s, followed by ? decay, was also observed. These events might originate from the decay of excited states in Lr257, populated by electron-capture decay of Rf257. Fission of Rf257 was unambiguously detected, with a branching ratio of bRfSF=0.02±0.01.

J. Qian; A. Heinz; T. L. Khoo; R. V. F. Janssens; D. Peterson; D. Seweryniak; I. Ahmad; M. Asai; B. B. Back; M. P. Carpenter; A. B. Garnsworthy; J. P. Greene; A. A. Hecht; C. L. Jiang; F. G. Kondev; T. Lauritsen; C. J. Lister; A. Robinson; G. Savard; R. Scott; R. Vondrasek; X. Wang; R. Winkler; S. Zhu

2009-06-22T23:59:59.000Z

16

Commercial SNF Accident Release Fractions  

SciTech Connect (OSTI)

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.

J. Schulz

2004-11-05T23:59:59.000Z

17

RF Interconnection and Switching  

Science Journals Connector (OSTI)

The components that connect, interface, transfer, and filter RF energy within a given system—or between systems—are critical elements in the operation of vacuum tube devices. Such hardware, usually passive, de...

Jerry C. Whitaker

1994-01-01T23:59:59.000Z

18

ISG8-RF Sources  

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

RF Sources - (WG3) RF Sources - (WG3) Orange Rm Yong Ho Chin, Christopher Nantista, and Sami G. Tantawi Parallel Sessions: Working Groups: WG1: Parameters, Design, Instrumentation and Tuning WG2: Damping Rings and ATF WG3: RF Sources WG4:Structures WG5: Ground Motion; Site Requirements and Investigations Monday Morning 9:00-10:30 Plenary Coffee Break 11:00-12:00 Planning Session. Monday Afternoon 13:30-15:30 High Gradient Issues (Joint with working group 4) Coffee Break 16:00-16:30 The 8-Pack Project -- D. Atkinson 16:30-17:30 High Gradient Issues and Discussions Continued. Tuesday Morning 9:30-10:30 Klystrons 9:30-10:00 Status of PPM Klystron Development for JLC -- Y. H. Chin 10:00-10:30 Design of 150MW Multi-Beam Klystron -- S. Matsumoto Coffee Break 11:00-11:30 Klystron Development at SLAC -- G. Caryotakis

19

Can RF help CMOS processors?  

E-Print Network [OSTI]

FOR C OMMUNICATIONS Can RF Help CMOS Processors? Eran SocherRF communication can help increase the wired communicationaluminum and low-K dielectrics help reduce wire delay but do

Socher, Eran; Chang, Mau-Chung Frank

2007-01-01T23:59:59.000Z

20

Advances in Photosynthesis and Respiration Series Editor  

E-Print Network [OSTI]

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

Govindjee "Gov"

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


21

RF current sensor  

DOE Patents [OSTI]

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1998-11-10T23:59:59.000Z

22

LABORATORY #5 --BIOL 111 Photosynthesis and Respiration  

E-Print Network [OSTI]

!) Photosynthesis can be defined as the transfer and storage of solar energy to a chemical form called glucose (a the world of life go `round: photosynthesis and respiration. One is about converting solar energy the standpoint of chemistry, photosynthesis is written like this: solar energy 6CO2 + 6H2O C6H12O6 + 6O2 Carbon

23

Announcement Advances in Photosynthesis and Respiration: Focus on Plant  

E-Print Network [OSTI]

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

Govindjee "Gov"

24

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

E-Print Network [OSTI]

EXPERIMENTAL STUDIES OF RF BREAKDOWNS IN THE COUPLER OF THE TTF RF GUN J.-P. Carneiro , S I, the RF gun of the TESLA Test Facility (TTF) has been operated with long RF pulses (up to 0.9 ms Fermilab has developed and delivered to DESY two RF guns for the operation of phase 1 of the TESLA Test

25

Diffusion in biofilms respiring on electrodes  

SciTech Connect (OSTI)

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.

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

2013-02-15T23:59:59.000Z

26

Cryogenic vacuumm RF feedthrough device  

DOE Patents [OSTI]

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.

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

2008-12-30T23:59:59.000Z

27

Size-Specific Respiration Rate of Port Hacking Zooplankton  

Science Journals Connector (OSTI)

The respiration rates of natural Zooplankton assemblages from Port Hacking, measured 4–5 h after capture,... % MathType!MTEF!2!1!+- % feaagCar...

David J. Tranter; Gillian Kennedy

1983-01-01T23:59:59.000Z

28

Respiration and photosynthesis in energy-transducing membranes of cyanobacteria  

Science Journals Connector (OSTI)

Cyanobacteria are photolithotrophic organisms exhibiting oxygenic photosynthesis. In the dark they satisfy their need for energy with respiration. These reactions occur in the same compartment and probably on ...

Andres Binder

1982-12-01T23:59:59.000Z

29

Note on RF Photo-Cathode Gun  

E-Print Network [OSTI]

Emittances in Laser-Driven RF Guns", Proc. 1988 Linear Acc.Palmer, "Preliminary Study of Gun Emittance Correction", BNLLaser-Driven RF Electron Guns", Nuc1. ln stt. Meth. , A275,

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

30

Simulation of synchrotron motion with rf noise  

SciTech Connect (OSTI)

The theoretical formulation is described that is behind an algorithm for synchrotron phase-space tracking with rf noise and some preliminary simulation results of bunch diffusion under rf noise obtained by actual tracking.

Leemann, B.T.; Forest, E.; Chattopadhyay, S.

1986-08-01T23:59:59.000Z

31

Intelligent Radio Frequency (RF) Monitoring  

E-Print Network [OSTI]

? Intelligent Radio Frequency (RF) Monitoring ? 2009 Armstrong International, Inc. www.armstronginternational.com 2 ?Expect many enjoyable experiences!? David M. Armstrong Present Process Challenges ? Identifying a failure ? Procedure.... Armstrong Steam Trap Challenges ? Identifying a failure ? Manpower ? Location ? Magnitude of failure ? Energy loss ? Loss of heat transfer ? Justification for repair ? ?Speed of Implementation? ? Environmental concerns Manpower Location 4...

Kimbrough, B.

32

SPL RF Coupler Cooling Efficiency  

E-Print Network [OSTI]

Energy saving is an important challenge in accelerator design. In this framework, reduction of heat loads in a cryomodule is of fundamental importance due to the small thermodynamic efficiency of cooling at low temperatures. In particular, care must be taken during the design of its critical components (e.g. RF couplers, coldwarm transitions). In this framework, the main RF coupler of the Superconducting Proton Linac (SPL) cryomodule at CERN will not only be used for RF powering but also as the main mechanical support of the superconducting cavities. These two functions have to be accomplished while ensuring the lowest heat in-leak to the helium bath at 2 K. In the SPL design, the RF coupler outer conductor is composed of two walls and cooled by forced convection with helium gas at 4.5 K. Analytical, semi-analytical and numerical analyses are presented in order to defend the choice of gas cooling. Temperature profiles and thermal performance have been evaluated for different operating conditions; a sensitivit...

Bonomi, R; Montesinos, E; Parma, V; Vande Craen, A

2014-01-01T23:59:59.000Z

33

High-Power Rf Load  

DOE Patents [OSTI]

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.

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

1998-09-01T23:59:59.000Z

34

Josephson device with a matched rf source  

SciTech Connect (OSTI)

Analog simulation of a resistance-shunted ac Josephson junction coupled to an rf source with matching impedance reveals (1) added structure in the device's V-I curve even when the source is quiescent and (2) rf-induced steps with peak amplitudes between those produced by voltage and current rf sources. Both results are consistent with experimental data.

Longacre, A. Jr.

1980-03-01T23:59:59.000Z

35

Scaling relationship between tree respiration rates and biomass  

Science Journals Connector (OSTI)

...relationship between tree respiration rates and biomass Dong-Liang Cheng 1 * Tao Li 2 Quan-Lin...scaled as the 0.82-power of aboveground biomass M A, and that total respiration rates R T scaled as the 0.85-power of total biomass M T, both of which significantly deviated...

2010-01-01T23:59:59.000Z

36

Coupling of Photosynthesis and Respiration Phloem Transport is  

E-Print Network [OSTI]

Coupling of Photosynthesis and Respiration ďż˝ 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

Simon, Emmanuel

37

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

E-Print Network [OSTI]

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

Govindjee "Gov"

38

Announcement Advances in Photosynthesis and Respiration, Volume 24  

E-Print Network [OSTI]

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

Govindjee "Gov"

39

E-Print Network 3.0 - alternative cyanide-insensitive respiration...  

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

Controls on Soil Respiration in the Dominant Patch Types of an Old-Growth, Mixed-Conifer Forest Summary: Biophysical Controls on Soil Respiration in the Dominant Patch...

40

Low jitter RF distribution system  

DOE Patents [OSTI]

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.

Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

2012-09-18T23:59:59.000Z

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


41

Single electron beam rf feedback free electron laser  

DOE Patents [OSTI]

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.

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

1981-02-11T23:59:59.000Z

42

HIGH-POWER RF DISTRIBUTION SYSTEMFOR THE 8-PACK PROJECT  

SciTech Connect (OSTI)

The 8-Pack Project at SLAC is a prototype rf system whose goal is to demonstrate the high-power X-band technology developed in the NLC/GLC (Next/Global Linear Collider) program. In its first phase, it has reliably produced a 400 ns rf pulse of over 500 MW using a solidstate modulator, four 11.424 GHz klystrons and a dualmoded SLED-II pulse compressor. In Phase 2, the output power of the system has been delivered into the bunker of the NLCTA (Next Linear Collider Test Accelerator) and divided between several accelerator structures for beam acceleration. The authors describe here the design, cold-test measurements, and processing of this power distribution system. Due to the high power levels and the need for efficiency, overmoded waveguide and components are used. For power transport, the TE{sub 01} mode is used in 7.44 cm and 4.064 cm diameter circular waveguide. Only near the structures is standard WR90 rectangular waveguide employed. Components used to manipulate the rf power include transitional tapers, mode converters, overmoded bends, fractional directional couplers, and hybrids.

Nantista, C

2004-08-24T23:59:59.000Z

43

RF Systems in a Neutrino Factory  

SciTech Connect (OSTI)

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

Berg J. S.

2012-09-07T23:59:59.000Z

44

RF Micro Devices | Open Energy Information  

Open Energy Info (EERE)

for Others) for this property. Partnering Center within NREL National Center for Photovoltaics Partnership Year 2009 RF Micro Devices is a company located in Greensboro, NC....

45

High voltage RF feedthrough bushing  

DOE Patents [OSTI]

Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

Grotz, Glenn F. (Huntington Station, NY)

1984-01-01T23:59:59.000Z

46

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

SciTech Connect (OSTI)

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.

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

2014-04-29T23:59:59.000Z

47

Note on RF Photo-Cathode Gun  

E-Print Network [OSTI]

E.R. Gray and P.M. Giles, "Photo-cathodes in AcceleratorProceedings Note on RF Photo-Cathode Gun K. -J. Kim August106 LBL-29538 Note on RF Photo-Cathode G un Kwang-Je Kim

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

48

RF SYSTEM FOR THE SNS ACCUMULATOR RING.  

SciTech Connect (OSTI)

During accumulation the RF beam current in the spallation neutron source ring rises from 0 to 50 amperes. A clean, 250 nanosecond gap is needed for the extraction kicker risetime. Large momentum spread and small peak current are needed to prevent instabilities and stopband related losses. A robust RF system meeting these requirements has been designed.

BLASKIEWICZ, M.; BRENNAN, J.M.; BRODOWSKI, J.; DELONG, J.; METH, M.; SMITH, K.; ZALTSMAN, A.

2001-06-18T23:59:59.000Z

49

Plasma Edge Cooling during rf Heating  

Science Journals Connector (OSTI)

A new approach to prevent the influx of high-Z impurities into the core of a tokamak discharge by using rf power to modify the edge plasma temperature profile is discussed. This concept is based on spectroscopic measurements on PLT (Princeton Large Torus) during ohmic heating and ATC (Adiabatic Toroidal Compressor) during rf heating.

S. Suckewer and R. J. Hawryluk

1978-06-19T23:59:59.000Z

50

DOE-HDBK-3010-94; Airborne Release Fractions/Rates and Respirable...  

National Nuclear Security Administration (NNSA)

SNL Ms. Wendy Ting, SAIC Dr. John Haschke, LANL Mr. John Van Kieren, WHC Mr. Hans Jordan, EG&G-Rocky Flats Dr. David Wilson, WSRC One additional special effort merits final...

51

R&D ERL: Low level RF  

SciTech Connect (OSTI)

A superconducting RF (SRF) Energy Recovery Linac (ERL) is currently under development at the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL). The major components from an RF perspective are (a) a 5-cell SRF ERL cavity, (b) an SRF photocathode electron gun, and (c) a drive laser for the photocathode gun. Each of these RF subsystems has its own set of RF performance requirements, as well as common requirements for ensuring correct synchronism between them. A low level RF (LLRF) control system is currently under development, which seeks to leverage both technology and experience gained from the recently commissioned RHIC LLRF system upgrade. This note will review the LLRF system requirements and describe the system to be installed at the ERL.

Smith, K.

2010-01-15T23:59:59.000Z

52

RF Cavity Characterization with VORPAL  

SciTech Connect (OSTI)

When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

C. Nieter, C. Roark, P. Stoltz, C.D. Zhou, F. Marhauser

2011-03-01T23:59:59.000Z

53

The Path of Carbon in Photosynthesis VII. Respiration and Photosynthesis  

DOE R&D Accomplishments [OSTI]

The relationship of respiration to photosynthesis in barley seedling leaves and the algae, Chlorella and Scenedesmus, has been investigated using radioactive carbon dioxide and the techniques of paper chromatography and radioautography. The plants are allowed to photosynthesize normally for thirty seconds in c{sup 14}O{sub 2} after which they are allowed to respire in air or helium in the light or dark. Respiration of photosynthetic intermediates as evidenced by the appearance of labeled glutomic, isocitric, fumaric and succinic acids is slower in the light than in the dark. Labeled glycolic acid is observed in barley and algae. It disappears rapidly in the dark and is maintained and increased in quantity in the light in C0{sub 2}-free air.

Benson, A. A.; Calvin, M.

1949-07-21T23:59:59.000Z

54

Simulations of Ion Migration in the LCLS RF Gun and Injector  

SciTech Connect (OSTI)

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.

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

2012-06-25T23:59:59.000Z

55

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.

56

The Emergence of RF-Powered Computing  

Science Journals Connector (OSTI)

Extracting power "from thin air" has a quality of science fiction about it, yet technology trends make it likely that in the near future, small computers in urban areas will use ambient RF signals for both power and communication. The first Web extra ... Keywords: Backscatter,RF signals,Radio frequency,Computers,Telemetry,TV,Power distribution,Wireless communication,Ubiquitous computing,emerging technologies,wireless communication,ubiquitous computing

Shyamnath Gollakota, Matthew Reynolds, Joshua Smith, David Wetherall

2014-01-01T23:59:59.000Z

57

RF MEMS reconfigurable triangular patch antenna.  

SciTech Connect (OSTI)

A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

Christodoulou, Christos George (The University of New Mexico, Albuquerque, NM); Nordquist, Christopher Daniel; Feldner, Lucas Matthew

2005-07-01T23:59:59.000Z

58

RF MEMS reconfigurable triangular patch antenna.  

SciTech Connect (OSTI)

A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

Nordquist, Christopher Daniel; Christodoulou, Christos George (University of New Mexico, Albuquerque, NM); Feldner, Lucas Matthew

2005-01-01T23:59:59.000Z

59

Relationship of Soil Respiration to Crop and Landscape in the Walnut Creek Watershed  

Science Journals Connector (OSTI)

Soil respiration is an important component of the carbon dynamics of terrestrial ecosystems. Many factors exert controls on soil respiration, including temperature, soil water content, organic matter, soil texture, and plant root activity. This ...

T. B. Parkin; T. C. Kaspar; Z. Senwo; J. H. Prueger; J. L. Hatfield

2005-12-01T23:59:59.000Z

60

Ris-R-1332(EN) Plant Respiration and Climate Change  

E-Print Network [OSTI]

Risø-R-1332(EN) Plant Respiration and Climate Change Effects Dan Bruhn Ph.D. thesis Plant Research, Roskilde April 2002 #12;Abstract The ongoing climate changes can affect many plant physiological processes. In turn, these effects on plants may result in a feedback between the climate change and the vegetation

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


61

ACCLIMATION OF PHOTOSYNTHESIS AND RESPIRATION TO INCREASING TEMPERATURES IN TREES  

E-Print Network [OSTI]

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

Teskey, Robert O.

62

Substrate regulation of soil respiration in a tallgrass prairie: Results of a clipping and shading experiment  

E-Print Network [OSTI]

. Temperature sensitivity of soil respiration decreased from 1.93 in the control plots to 1.88, 1.75, and 1 of substrate supply in regulating soil respiration and its temperature sensitivity. INDEX TERMS: 1615 Global in a tallgrass prairie of the Great Plains, United States, to manipulate substrate supply to soil respiration

63

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

E-Print Network [OSTI]

1 Application of Kernel Principal Component Analysis for Single Lead ECG-Derived Respiration Devy signal from ECGs. In this study, an improved ECG-derived respiration (EDR) algorithm based on kernel PCA ECGs. Index Terms--ECG-derived respiration (EDR), kernel princi- pal component analysis (kPCA). I

64

ARM - Measurement - Cloud fraction  

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

to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Cloud fraction Fraction of sky covered by clouds, observed directly or derived from SW...

65

RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES  

SciTech Connect (OSTI)

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.

Johnson, Rolland

2014-09-21T23:59:59.000Z

66

Rf capacitively-coupled electrodeless light source  

DOE Patents [OSTI]

An rf capacitively-coupled electrodeless light source is provided. The light source comprises a hollow, elongated chamber and at least one center conductor disposed within the hollow, elongated chamber. A portion of each center conductor extends beyond the hollow, elongated chamber. At least one gas capable of forming an electronically excited molecular state is contained within each center conductor. An electrical coupler is positioned concentric to the hollow, elongated chamber and the electrical coupler surrounds the portion of each center conductor that extends beyond the hollow, elongated chamber. A rf-power supply is positioned in an operable relationship to the electrical coupler and an impedance matching network is positioned in an operable relationship to the rf power supply and the electrical coupler.

Manos, Dennis M. (Williamsburg, VA); Diggs, Jessie (Norfolk, VA); Ametepe, Joseph D. (Roanoke, VA); Fugitt, Jock A. (Livingston, TX)

2000-01-01T23:59:59.000Z

67

X-Band RF Gun Development  

SciTech Connect (OSTI)

In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; /SLAC; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

2012-06-22T23:59:59.000Z

68

Evaluation of respirator fit training by quantitative fit testing  

E-Print Network [OSTI]

that all respirator wearers be trained and f1t tested. In additiion, as part of a complete respiratory protection program, the effect1veness of resp1rator use training should be appraised at periodic 1ntervals. The purpose of this experiment... of trained individuals was able to significantly improve their measured protection factors when compared to the untrained control group. In addition, when fit tests were re- peated on the same day, the second test resulted in consistently higher scores...

Chute, Daniel Otis

2012-06-07T23:59:59.000Z

69

A day in the life of the RF spectrum  

E-Print Network [OSTI]

There is a misguided perception that RF spectrum space is fully allocated and fully used though even a superficial study of actual spectrum usage by measuring local RF energy shows it largely empty of radiation. Traditional ...

Cooley, James E. (James Edward)

2005-01-01T23:59:59.000Z

70

Novel rf mems tunable filters with adjustable spurious suppression  

E-Print Network [OSTI]

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...

Sekar, Vikram

2009-05-15T23:59:59.000Z

71

Fractional Electromagnetic Waves  

E-Print Network [OSTI]

In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía

2011-08-31T23:59:59.000Z

72

Fractions continues Michel Waldschmidt  

E-Print Network [OSTI]

´erentes oeuvres d'art, 2 appara^it aussi dans des oeuvres artistiques persanes. 2 #12;Figure 1. Fraction continue

Waldschmidt, Michel

73

RF Design of the LCLS Gun  

SciTech Connect (OSTI)

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.

Limborg-Deprey, C

2010-12-13T23:59:59.000Z

74

Fabrication of Niobium sheet for RF cavities  

E-Print Network [OSTI]

..................................................................................... 18 2 Fabrication of Niobium SRF Cavities............................................. 20 3 Fine Grain Cavities versus Single Crystal and Large Grain........... Cavities... typical to that of RF cavities in comparison with Cu at 77 and 300K. Nb has low surface resistance in the operating range of 1GHz among the metals. [27]. 2. Fabrication of Niobium SRF Cavities There are different approaches involved in making...

Balachandran, Shreyas

2009-05-15T23:59:59.000Z

75

Spontaneous fission properties of Rf104262  

Science Journals Connector (OSTI)

We have measured the mass and kinetic-energy distributions of fragments from the spontaneous fission (SF) of Rf104262. The Rf104262 was produced via the Pu244(22Ne,4n) reaction with a production cross section of ?0.7 nb using 114.4-MeV projectiles. The kinetic energies and times of the coincident fission fragments were measured using our rotating wheel system. From these data the half-life, mass, and kinetic-energy distributions were derived. The total kinetic-energy (TKE) distribution appears to consist of a single component with a most probable pre-neutron-emission TKE of 215±2 MeV. The mass distribution is symmetric with a full width at half maximum of about 22 mass numbers. These results are consistent with trends observed for other trans-berkelium spontaneously fissioning isotopes. We determined the half-life to be 2.1±0.2 s by measuring its spontaneous fission decay. We also attempted to observe the alpha decay of Rf104262 by searching for alpha decay correlated in time with SF from the alpha daughter, 1.2-ms No258. We observed no such decays and have set an upper limit of 0.8% (68% confidence level) on the alpha decay branch of Rf104262. © 1996 The American Physical Society.

M. R. Lane; K. E. Gregorich; D. M. Lee; M. F. Mohar; M. Hsu; C. D. Kacher; B. Kadkhodayan; M. P. Neu; N. J. Stoyer; E. R. Sylwester; J. C. Yang; D. C. Hoffman

1996-06-01T23:59:59.000Z

76

Configurations for short period rf undulators  

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

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.

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

2013-07-01T23:59:59.000Z

77

Rf beam control for the AGS Booster  

SciTech Connect (OSTI)

RF beam control systems for hadron synchrotrons have evolved over the past three decades into an essentially standard design. The key difference between hadron and lepton machines is the absence of radiation damping and existence of significant frequency variation in the case of hadrons. Although the motion of the hadron in the potential well of the rf wave is inherently stable it is not strongly damped. Damping must be provided by electronic feedback through the accelerating system. This feedback is typically called the phase loop. The technology of the rf beam control system for the AGS Booster synchrotron is described. First, the overall philosophy of the design is explained in terms of a conventional servo system that regulates the beam horizontal position in the vacuum chamber. The concept of beam transfer functions is fundamental to the mathematics of the design process and is reviewed. The beam transfer functions required for this design are derived from first principles. An overview of the beam signal pick-ups and high level rf equipment is given. The major subsystems, the frequency program, the heterodyne system, and beam feedback loops, are described in detail. Beyond accelerating the beam, the rf system must also synchronize the bunches in the Booster to the buckets in the AGS before transfer. The technical challenge in this process is heightened by the need to accomplish synchronization while the frequency is still changing. Details of the synchronization system are given. This report is intended to serve two purposes. One is to document the hardware and performance of the systems that have been built. The other is to serve as a tutorial vehicle from which the non-expert can not only learn the details of this system but also learn the principles of beam control that have led to the particular design choices made.

Brennan, J.M.

1994-09-26T23:59:59.000Z

78

Localized Plasticity in the Streamlined Genomes of Vinyl Chloride Respiring Dehalococcoides  

E-Print Network [OSTI]

2005) Genome sequence of the PCE-dechlorinating bacteriumlevels and pseudo-steady-state PCE respiration rates inreductive dehalogenases in a PCE-dechlorinating flow column.

McMurdie, Paul J.

2010-01-01T23:59:59.000Z

79

E-Print Network 3.0 - air-purifying respirator cartridges Sample...  

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

immediately wash skin... PRECAUTION(S) Wear respirator, chemical safety goggles, rubber boots, and heavy ... Source: Vakni, David - Ames Laboratory Collection: Materials Science 99...

80

E-Print Network 3.0 - air-purifying respirator performance Sample...  

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

immediately wash skin... PRECAUTION(S) Wear respirator, chemical safety goggles, rubber boots, and heavy ... Source: Vakni, David - Ames Laboratory Collection: Materials Science 99...

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


81

E-Print Network 3.0 - alkaline anaerobic respiration Sample Search...  

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

2 3 4 5 > >> 1 The Effects of Benthic Organic Matter Quality on Aerobic and Anaerobic Sediment Metabolism in West Falmouth Harbor Summary: , respectively. Anaerobic respiration...

82

ILC RF System R and D  

SciTech Connect (OSTI)

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.

Adolphsen, Chris; /SLAC

2012-07-03T23:59:59.000Z

83

The new RF sources for accelerators  

SciTech Connect (OSTI)

Several new RF sources are being developed for accelerator and collider applications. Assembly is nearing completion of a multiple beam inductive output tube at 352 MHz. An annular beam klystron is being developed to produce 10 MW pulses at 1.3 GHz. The annular beam approach provides significant cost reduction over similar multiple beam devices. Fabrication is underway on a 10 kW, periodic permanent magnet klystron at 2.815 GHz. Permanent magnets eliminate the solenoid and associated power supplies and cooling requirements to reduce operational cost. Investigations are beginning on a novel approach for driving accelerator cavities using pulse shaping to increase coupling efficiency and dramatically reduce RF power requirements.

Ives, Lawrence; Read, Michael; Ferguson, Patrick; Marsden, David; Collins, George; Jackson, R. H.; Bui, Thuc; Kimura, Takuji; Eisen, Edward [Calabazas Creek Research, Inc., 690 Port Drive, San Mateo, CA, 94404, (650) 312-9575 (United States); Communications and Power Industries, LLC., 811 Hansen Way, Palo Alto, CA94304 (United States)

2012-12-21T23:59:59.000Z

84

The effect of temperature and humidity on respirator fit  

E-Print Network [OSTI]

. Figure l - Half-Hask Respirator Used in This Research 17 Oualitative fit tests using isoamyl acetate (IAA) were conducted in the Human Factors Chamber located at Texas A8M University, shown in Figure 2. The airborne concentration of isoamyl acetate... Equipment-III. Practical Performance Test. Am. Ind. ~H. Assoc. J. 44:772-773 (1983). Guyto, A. C. : T th h f Ii di I ~ph si I . Ch pt 39, II. G. S de s Comps y~ew glfhft, J. G. (Gdt 3: F d tIs fidsti 1~8 Ch Pt 2, Natio ai Safety Co cote cago, TT tggygt...

Niekerk, Gary

2012-06-07T23:59:59.000Z

85

Safety assessment for the rf Test Facility  

SciTech Connect (OSTI)

The Radio Frequency Test Facility (RFTF) is a part of the Magnetic Fusion Program's rf Heating Experiments. The goal of the Magnetic Fusion Program (MFP) is to develop and demonstrate the practical application of fusion. RFTF is an experimental device which will provide an essential link in the research effort aiming at the realization of fusion power. This report was compiled as a summary of the analysis done to ensure the safe operation of RFTF.

Nagy, A.; Beane, F. (eds.)

1984-08-01T23:59:59.000Z

86

Radio frequency (RF) heated supersonic flow laboratory  

SciTech Connect (OSTI)

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.

Wantuck, P.; Watanabe, H.

1990-01-01T23:59:59.000Z

87

Superconducting RF systems for eRHIC  

SciTech Connect (OSTI)

The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

Belomestnykh S.; Ben-Zvi, I.; Brutus, J.C.; Hahn, H. et al

2012-05-20T23:59:59.000Z

88

Production of potentially hazardous respirable silica airborne particulate from the burning of sugarcane  

Science Journals Connector (OSTI)

In some areas of the world where agricultural burning is practised, the airborne particles produced have been linked to respiratory disease in humans. Here, we investigate the abundance and form of silica (SiO2) minerals found within ash and aerosol produced by the experimental burning of sugarcane. Samples of sugarcane leaf were incinerated over a range of temperatures, time scales and airflow conditions, the latter to investigate the effects of wind and updrafts during natural fires. The silica content of the residual ash (from still air simulations) was measured using an improved wet chemical methodology, described here. This indicated that the release of silica from the plant material into the atmosphere increases with increasing temperature of combustion. Airborne particulate, sampled using air-pump-filter apparatus, was characterised using scanning electron microscopy (SEM) with automated image and elemental analysis. For airborne particulate formed at 1100 °C (with airflow), 17% of the particles are in the respirable size fraction (release of cristobalite to the atmosphere (as sampled on filters). This pilot study shows that potentially toxic particles could be released during sugarcane burning and reinforces the need for further study into the emissions and re-suspension of ash from the burning of biomass.

Jennifer S. Le Blond; Ben J. Williamson; Claire J. Horwell; Alex K. Monro; Caroline A. Kirk; Clive Oppenheimer

2008-01-01T23:59:59.000Z

89

A discrete fractional random transform  

E-Print Network [OSTI]

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.

Zhengjun Liu; Haifa Zhao; Shutian Liu

2006-05-20T23:59:59.000Z

90

Enumeration of Particle-Bound and Unattached Respiring Bacteria in the Salt Marsh Environment  

Science Journals Connector (OSTI)

...Respiring Bacteria in the Salt Marsh Environment R. W. Harvey L. Y. Young...Respiring Bacteria in the Salt Marsh Environment R. W. HARVEY AND L. Y...and particulates in salt marsh surface water. Appl...6. Hobbie, J. E., R. J. Daley, and S...

R. W. Harvey; L. Y. Young

1980-07-01T23:59:59.000Z

91

The purpose of a respirator is to prevent the user from inhaling harmful  

E-Print Network [OSTI]

. Since the contaminants are still present in the air, it is extremely important that: · the respirator and the seal checked each time you use it. INSPECTION Before each use inspect your respirator as follows and straps are properly connected. · Ensure the face seal surface is clean and free of any cracks

Machel, Hans

92

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

E-Print Network [OSTI]

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...

Britton, Robert Grant

1996-01-01T23:59:59.000Z

93

An improved ECG-Derived Respiration Method using Kernel Principal Component Analysis  

E-Print Network [OSTI]

An improved ECG-Derived Respiration Method using Kernel Principal Component Analysis Devy Widjaja1) of heart beats generates well-performing ECG- derived respiratory signals (EDR). This study aims at im in the extraction of a respiratory signal from single lead ECGs. 1. Introduction Respiration is often jointly

94

Fractional vortices and lumps  

SciTech Connect (OSTI)

We study what might be called fractional vortices, vortex configurations with the minimum winding from the viewpoint of their topological stability, but which are characterized by various notable substructures in the transverse energy distribution. The fractional vortices occur in diverse Abelian or non-Abelian generalizations of the Higgs model. The global and local features characterizing these are studied, and we identify the two crucial ingredients for their occurrence--the vacuum degeneracy leading to nontrivial vacuum moduli M, and the BPS nature of the vortices. Fractional vortices are further classified into two kinds. The first type of such vortices appear when M has orbifold Z{sub n} singularities; the second type occurs in systems in which the vacuum moduli space M possesses either a deformed geometry or some singularity. These general features are illustrated with several concrete models.

Eto, Minoru; Gudnason, Sven Bjarke; Konishi, Kenichi [Department of Physics, University of Pisa, Largo Pontecorvo, 3, Building C, 56127 Pisa (Italy); INFN, Sezione di Pisa, Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Fujimori, Toshiaki; Nagashima, Takayuki [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan); Nitta, Muneto [Department of Physics, Keio University, Hiyoshi, Yokohama, Kanagawa 223-8521 (Japan); Ohashi, Keisuke [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA (United Kingdom); Vinci, Walter [Department of Physics, University of Pisa, Largo Pontecorvo, 3, Building C, 56127 Pisa (Italy); INFN, Sezione di Pisa, Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA (United Kingdom)

2009-08-15T23:59:59.000Z

95

A STATE VARIABLE DESCRIPTION OF THE RHIC RF CONTROL LOOPS.  

SciTech Connect (OSTI)

The beam transfer function changes during the RHIC ramp. The response of the RF control loops changes as a result. A state-variable description of the beam and the RF control loops was developed. This description was used to generate a set of feedback matrices that keeps the response of the RF control loops constant during the ramp. This paper describes the state-variable description and its use in determining the K matrices.

SCHULTHEISS,C.; BRENNAN,J.M.

2002-06-02T23:59:59.000Z

96

Fractional Standard Map  

E-Print Network [OSTI]

Properties of the phase space of the standard map with memory are investigated. This map was obtained from a kicked fractional differential equation. Depending on the value of the parameter of the map and the fractional order of the derivative in the original differential equation this nonlinear dynamical system demonstrates attractors (fixed points, stables periodic trajectories, slow converging and slow diverging trajectories, ballistic trajectories, and fractal-like structures) and/or chaotic trajectories. At least one type of fractal-like sticky attractors in the chaotic sea was observed.

Mark Edelman; Vasily E. Tarasov

2009-11-24T23:59:59.000Z

97

Active high-power RF switch and pulse compression system  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

98

Biophysical Controls on Soil Respiration in the Dominant Patch Types of an Old-Growth, Mixed-Conifer Forest  

E-Print Network [OSTI]

, Ho¨gberg et al. 2001). These processes are interrelated and affected by multiple biophysical factors). Soil respiration is related to many ecological processes, such as photosyn- thesis, root respiration in an ecosys- tem. Soil respiration is also associated with physical CO2 diffusion processes affected

Chen, Jiquan

99

Extremely high frequency RF effects on electronics.  

SciTech Connect (OSTI)

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.

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

100

Booster Synchrotron RF System Upgrade for SPEAR3  

SciTech Connect (OSTI)

Recent progress at the SPEAR3 includes the increase in stored current from 100 mA to 200 mA and top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase the stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. The present booster RF system is basically a copy of the SPEAR2 RF system with 358.5 MHz and 40 kW peak RF power driving a 5-cell RF cavity for 1.0 MV gap voltage. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system of 476.3 MHz with 1.2 MW cw klystron output power capabilities. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II RF stations.

Park, Sanghyun; /SLAC; Corbett, Jeff; /SLAC

2012-07-06T23:59:59.000Z

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


101

RF cavity using liquid dielectric for tuning and cooling  

DOE Patents [OSTI]

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.

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

2012-04-17T23:59:59.000Z

102

Upgrade of the cryogenic CERN RF test facility  

SciTech Connect (OSTI)

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.

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

103

Cold Test Measurements on the GTF Prototype RF Gun  

SciTech Connect (OSTI)

The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Based on longitudinal phase space measurements showing a correlated energy spread the gun was removed and re-characterized in 2002. The low power RF measurements performed on the gun are described below. Perturbative bead measurements were performed to determine the field ratio in the two-cell gun, and network analyzer measurements were made to characterize the mode structure. A second probe was installed to monitor the RF field in the first cell, and a diagnostic was developed to monitor the high-power field ratio. Calibration of the RF probes, a model for analyzing RF measurements, and Superfish simulations of bead and RF measurements are described.

Gierman, S.M.

2010-12-03T23:59:59.000Z

104

Hydrogen-filled RF Cavities for Muon Beam Cooling  

SciTech Connect (OSTI)

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.

CHARLES, Ankenbrandt

2009-04-17T23:59:59.000Z

105

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

E-Print Network [OSTI]

addition, the small equivalent resistance of 8? of the RF PAor inefficient. The equivalent resistance of RF PA, R PA ,normalized equivalent load resistance (R PA ) representing

Hassan, Muhammad

2012-01-01T23:59:59.000Z

106

Large Grain Superconducting RF Cavities at DESY  

SciTech Connect (OSTI)

The DESY R and D program on cavities fabricated from large grain niobium explores the potential of this material for the production of approx. 1000 nine-cell cavities for the European XFEL. The program investigates basic material properties, comparing large grain material to standard sheet niobium, as well as fabrication and preparation aspects. Several single-cell cavities of TESLA shape have been fabricated from large grain niobium. A gradient up to 41 MV/m at Q0 = 1.4{center_dot}1010 (TB = 2K) was measured after electropolishing. The first three large grain nine-cell cavities worldwide have been produced under contract of DESY with ACCEL Instruments Co. The first tests have shown that all three cavities reach an accelerating gradient up to 30 MV/m after BCP (Buffered Chemical Polishing) treatment, what exceeds the XFEL requirements for RF test in the vertical cryostat.

Singer, W.; Brinkmann, A.; Ermakov, A.; Iversen, J.; Kreps, G.; Matheisen, A.; Proch, D.; Reschke, D.; Singer, X.; Spiwek, M.; Wen, H.; Brokmeier, H. G. [DESY, Notkestrasse 85, D-22607 Hamburg (Germany); GKSS, Max-Planck-Strasse, D-21502 Geesthacht (Germany)

2007-08-09T23:59:59.000Z

107

Extraction, Degradation, and Microbial Respiration Effects of Mesotrione in Selected Texas Soils  

E-Print Network [OSTI]

of atrazine on mesotrione degradation in soil; and 3) determine if mesotrione, mesotrione + atrazine treatments, and application rates had an impact on soil microbial activity (respiration). In the first experiment, mesotrione recoveries were...

Romero, Madahy B

2014-08-08T23:59:59.000Z

108

Overview of organohalide-respiring bacteria and a proposal for a classification system for reductive dehalogenases  

Science Journals Connector (OSTI)

...demonstrated to conserve energy via organohalide respiration...halogenated substrates for energy conservation in a respiratory process...are all available for public access and editing at...family, and to aid communication about and comparison...

2013-01-01T23:59:59.000Z

109

E-Print Network 3.0 - annual ecosystem respiration Sample Search...  

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

9 CO2Exchange(umolCO2m2 duringdaytime) Summary: respiration. Ecosystem carbon and water exchange are not affected by the watering event. In April, however... carbon flux ...

110

A Global Database of Soil Respiration Data, Version 2.0  

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

Home > Data > Regional/Global > Soil Collections > Guide Document Home > Data > Regional/Global > Soil Collections > Guide Document A Global Database of Soil Respiration Data, Version 2.0 Get Data Revision date: February 24, 2012 Summary This data set provides an updated soil respiration database (SRDB), a near-universal compendium of published soil respiration (RS) data. Soil respiration, the flux of autotrophically- and heterotrophically-generated CO2 from the soil to the atmosphere remains the least well-constrained component of the terrestrial C cycle. The database encompasses all published studies that report at least one of the following data measured in the field (not laboratory): annual RS, mean seasonal RS, a seasonal or annual partitioning of RS into its sources fluxes, RS temperature response (Q10), or RS at 10 degrees C. SRDB's orientation is thus to seasonal and

111

Solvent Fractionation of Lignin  

SciTech Connect (OSTI)

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.

Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL

2014-01-01T23:59:59.000Z

112

Studies of RF Noise Induced Bunch Lengthening at the LHC  

SciTech Connect (OSTI)

Radio Frequency (RF) noise induced bunch lengthening can strongly affect the Large Hadron Collider (LHC) performance through luminosity reduction, particle loss, and other effects. This work presents measurements from the LHC that better quantify the relationship between the RF noise and longitudinal emittance blowup and identify the performance limiting RF components. The experiments presented in this paper confirmed the predicted effects on the LHC bunch length growth. Dedicated measurements were conducted in the LHC to gain insight in the effect of RF noise to the longitudinal beam diffusion. It was evident that the growth rate of the bunch length is strongly related to the accelerating voltage phase noise power spectral density around f{sub s} + kf{sub rev}, as predicted in [4]. The noise threshold for 2.5 ps/hr growth was estimated to -101 dBc/Hz (SSB flat noise spectral density from f{sub s} to the edge of the closed loop bandwidth). A 9 dB margin is achieved with the current RF configuration and the BPL on. With this formalism it is now possible to estimate the effect of different operational and technical RF configurations on the LHC beam diffusion. This formalism could also be useful for the design of future RF systems and the budgeting of the allowed noise.

Mastorides, T.; Rivetta, C.; Fox, J.D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /SLAC /CERN

2011-08-17T23:59:59.000Z

113

Upgrading EMMA to Use Low-frequency RF Cavities  

SciTech Connect (OSTI)

EMMA is an experiment to study beam dynamics in fixed field alternating gradient accelerators (FFAGs). It accelerates the beam in about 10 turns using 1.3 GHz cavities in a mode like that used for muon accelerators. Many applications of FFAGs prefer to have slower acceleration, typically thousands of turns. To do so in EMMA would require the RF system to be replaced with a low-frequency, high-gradient system. This paper describes the motivation for studying slow acceleration in EMMA and the required parameters for an RF system to do that. It then describes the technology needed for the RF system.

Ohmori, C.; Berg, J.

2011-04-30T23:59:59.000Z

114

Iris tilting and RF steering in the SLAC Linac  

SciTech Connect (OSTI)

For some time now, the sources of RF transverse beam steering in the SLAC Linac have been a mystery. The previously known sources, coupler asymmetries and survey misalignment, have predicted deflections which are frequently much smaller than the observed deflections. A new source of RF steering has been discovered: the tilting of accelerator irises. Measurements of iris tilting in a forty foot accelerator girder are compared with measurements of RF beam deflections and are found to be strongly correlated. 4 refs., 6 figs., 3 tabs.

Seeman, J.T.

1985-05-02T23:59:59.000Z

115

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

DOE Patents [OSTI]

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.

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

2008-04-22T23:59:59.000Z

116

A Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source  

E-Print Network [OSTI]

: The electron extraction from a low-frequency (2 MHz) inductively-coupled rf-plasma cathode is characterizedA Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source and rf-plasma source, rf-power and xenon gas flow. The results demonstrate that the electron supply from

117

RF Micro Devices Inc RFMD | Open Energy Information  

Open Energy Info (EERE)

RF Micro Devices Inc RFMD RF Micro Devices Inc RFMD Jump to: navigation, search Name RF Micro Devices, Inc. (RFMD) Place Greensboro, North Carolina Zip 27409-9421 Product RF Micro Devices, Inc. is a global leader in the design and manufacture of high-performance semiconductor components. Coordinates 44.576059°, -72.294016° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.576059,"lon":-72.294016,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

118

Development of the RF plasma source at atmospheric pressure  

Science Journals Connector (OSTI)

A radio frequency (RF) plasma source operates by feeding helium or argon gas through two coaxial electrodes driven by a 13.56 \\{MHz\\} RF source. In order to prevent an arc discharge, a dielectric material is loaded outside the center electrode. A stable, arc-free discharge is produced at a flow rate of 1.5 l/min of helium gas. The temperature of the gas flame varies from 100 to 150 °C depending on the RF power. The breakdown voltage also changes when the flow rate varies. The plasma generation in a hot chamber is much more efficient than that in a cold chamber. The plasma characteristics are diagnosed by using optical emission spectroscopy. One of the applications of the RF plasma source is the printed circuit board (PCB) cleaning process, needed for environmental protection. The PCB cleaning device forms an asymmetric biaxial reactor.

Jung G. Kang; Hyoung S. Kim; Sung W. Ahn; Han S. Uhm

2003-01-01T23:59:59.000Z

119

BN/Graphene/BN Transistors for RF Applications  

E-Print Network [OSTI]

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 ...

Taychatanapat, Thiti

120

RF Sputtering for preparing substantially pure amorphous silicon monohydride  

DOE Patents [OSTI]

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.

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

1982-10-12T23:59:59.000Z

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


121

Supply Chain Planning Analyst 4 Optical Components /RF Products  

E-Print Network [OSTI]

Components/RF Products Technology Domain Teams. The SCPA will have responsibility for managing management, subcontract administration, procurement, mission assurance, engineering, and manufacturing Qualifications: The selected analysts must have the demonstrated ability to thrive in a dynamic environment

Heller, Barbara

122

RF power amplifier linearity compensation for MRI systems  

E-Print Network [OSTI]

In this thesis, a polar-feedback linearization system for use with MRI RF power amplifiers was designed and simulated. The design here presented is intended to replace Analogic's (located in Peabody, Massachusetts) ...

Torres Chico, Gabriel

2010-01-01T23:59:59.000Z

123

Handbook for Gas Filled RF Cavity Aficionados'  

SciTech Connect (OSTI)

The use of hydrogen gas filled RF cavities in muon cooling channels has been proposed by Rolland Johnson. Impressive results have been obtained toward attaining high voltage gradients and rapid training in preliminary tests done at the FNAL MTA facility. However, so far it has not been possible to test them under conditions where they were subject to the transversal of a high intensity particle beam. This note is an attempt to bring together a description of some of the pertinent physical processes that take place in the dilute plasma that is generated in the hydrogen gas by the beam. Two effects dominate. The first is that the free electrons generated can load down the cavity and transfer its energy to heating the gas. The second is a question of what happens to the plasma in the longer term. There is an enormous literature on the subject of the subject of dilute hydrogen plasmas and we can tap into this information in order to understand and predict the behavior of the cavity.

Tollestrup, A.V.; Chung, Moses; Yonehara, Katsuya; /Fermilab

2009-05-01T23:59:59.000Z

124

RF heating needs and plans for ITER  

SciTech Connect (OSTI)

RF heating systems are required to deliver more than half of the total auxiliary power to operate ITER successfully through the different levels. To achieve this goal, systems in the range of ICRF, LHF and ECRF will be implemented for different tasks in different phases of operation. Power levels proposed to be used in different ranges will vary depending on the needs. Different mixes of power will depend on the physics needs of the experimental programmes. Lower Hybrid power of 20 MW at 5.0 GHz is not planned for the startup phase and therefore no procurement scheme exists at the present time. 20 MW will be delivered into the plasma at 40 to 55 MHz as well as at 170 GHz with the help of Ion Cyclotron Heating (ICH) and Electron Cyclotron Heating (ECH) systems respectively. All the heating systems will have the capability to operate in continuous mode. A dedicated ECH 3.0 MW system at 127.6 GHz will be used for plasma breakdown and start up.

Bora, Dhiraj; Beaumont, B.; Kobayashi, N.; Tanga, A. [ITER Organization, Joint Work Site, Cadarache (France); Goulding, R.; Swain, D. [Oak Ridge National Laboratory (United States); Jacquinot, J. [Cabinet of High Commissioner for Atomic Energy, CEA Gif-sur-Yvette (France)

2007-09-28T23:59:59.000Z

125

Pulses inside the pulse mode of operation at RF Gun  

E-Print Network [OSTI]

Pulses inside the pulse mode of operation at RF Gun V. Vogel, V. Ayvazyan, K. Floettmann, D. Lipka a PiP mode of operation at RF Gun · What we need, to operate FLASH in the PiP mode · PiP study-Universitaet Bochum) Alternative: SC GUN DC GUN Cold GUN in PiP mode Cold Traveling wave GUN Why we need a PiP mode

126

Incompressible Stars and Fractional Derivatives  

E-Print Network [OSTI]

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.

S. S. Bayin; J. P. Krisch

2014-08-21T23:59:59.000Z

127

Equilibrium Analysis of EC-Sustained and RF-Sustained ST Plasmas  

SciTech Connect (OSTI)

Plasma current start-up and formation of the ST configuration without the use of the central solenoid is a critical issue in ST research. In the TST-2 spherical tokamak (R = 0.38 m, a = 0.25 m), sustainment of an ECRF (2.45 GHz) produced ST plasma by low frequency (21 MHz) RF power alone was demonstrated. Since direct RF current drive can be ruled out, this result implies that the ST configuration is sustained entirely by pressure-driven currents. The Grad-Shafranov equilibrium was generalized to take into account the open field line region with finite plasma current and pressure (truncated equilibrium). In addition to the precessional current of trapped particles, Pfirsch-Schlueter current flowing along the open field line (and partially returning through the vacuum vessel) contributes to the toroidal plasma current. Three phases of plasma start-up are analyzed: (i) the current formation phase, (ii) the current jump phase, and (iii) the current sustainment phase. In the current formation phase, the plasma current is formed and increases slowly, roughly proportional to the stored energy. Closed flux surfaces do not exist and the current density profile is peaked on the outboard side. Once the plasma current increases beyond a critical value (approximately equal to the level necessary to satisfy the major radial force balance), the plasma current increases rapidly (current jump). Closed flux surfaces appear not at the beginning, but at the end of the current jump. In the sustainment phase, plasma has a high poloidal beta, {beta}{sub p} O(1). The equilibrium is characterized by the hollowness of the current density profile, which also determines the fraction of the plasma current inside the last closed flux surface. The plasma equilibrium does not differ greatly between EC-sustained and RF-sustained plasmas. However, RF-sustained plasmas are more turbulent, with larger fluctuation levels over a wide frequency band (0-20 kHz), and in many cases MHD activity in the 5-10 kHz frequency band increases rapidly and terminates the discharge.

Takase, Y.; Ejiri, A.; Nagashima, Y.; Watanabe, O.; An, B. I.; Hayashi, H.; Hanashima, K.; Hiratsuka, J.; Kakuda, H.; Kobayashi, H.; Kurashina, H.; Matsuzawa, H.; Oosako, T.; Sakamoto, T.; Wakatsuki, T.; Yamada, K.; Yamaguchi, T. [University of Tokyo, Kashiwanoha 5-1-5, Kashiwa 277-8561 (Japan)

2009-11-26T23:59:59.000Z

128

Sedimentation Field Flow Fractionation: Applications  

Science Journals Connector (OSTI)

...FIELD-FLOW FRACTIONATION OF ALKALI-LIBERATED NUCLEAR POLYHEDROSIS-VIRUS FROM GYPSY-MOTH...FRACTIONATION TO RADIOACTIVE-WASTE DISPOSAL, NUCLEAR TECHNOLOGY 51 : 147 ( 1980 ). SOBER...perThe SFFF separation in Fig. 9a was ic dispersant moarbitrarily concluded shortly after...

J. J. Kirkland; W. W. Yau

1982-10-08T23:59:59.000Z

129

Microsoft PowerPoint - rf_5year_review  

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

RF Research Program RF Research Program DOE Review of C-Mod Five-Year Proposal May 13-14, 2003 MIT PSFC Presented by Steve J.Wukitch Outline: 1. Overview of the RF Program 2. Five-year plan Overview of the RF Program AT: validate steady state operation with target parameters β N = 3, I non = 100%, I BS ~ 70%, H 89 ~ 2.5, for t pulse > t L/R . BPX: demonstrate the viability of high performance plasmas, B T = 8T, I p = 2 MA, P = 6 MW, H 89 ≥ 2, Z eff < 1.5. B T = 5.4T, I p = 1.4 MA, P = 6 MW, H 89 = 2 (ITER demo) Exclusively use RF power for auxiliary heating and current drive. variable variable fixed Phase 2 x 4 Strap 4 Strap 2 x 2 Strap Antenna 4 MW 40-80 MHz J-port 2 x 4 MW 2 x 2 MW Power 40-80 MHz ~ 80 MHz Frequency E & J-port D & E-port 2005-2008 2002-2005 4.6 GHz 4.6 GHz Frequency 16 x 250 kW

130

RF Power Upgrade for CEBAF at Jefferson Laboratory  

SciTech Connect (OSTI)

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.

Andrew Kimber,Richard Nelson

2011-03-01T23:59:59.000Z

131

Phase Stable RF-over-fiber Transmission using Heterodyne Interferometry  

SciTech Connect (OSTI)

New scientific applications require phase-stabilized RF distribution to multiple remote locations. These include phased-array radio telescopes and short pulse free electron lasers. RF modulated onto a CW optical carrier and transmitted via fiber is capable of low noise, but commercially available systems aren't long term stable enough for these applications. Typical requirements are for less than 50fs long term temporal stability between receivers, which is 0.05 degrees at 3GHz. Good results have been demonstrated for RF distribution schemes based on transmission of short pulses, but these require specialized free-space optics and high stability mechanical infrastructure. We report a method which uses only standard telecom optical and RF components, and achieves less than 20fs RMS error over 300m of standard single-mode fiber. We demonstrate stable transmission of 3GHz over 300m of fiber with less than 0.017 degree (17fs) RMS phase error. An interferometer measures optical phase delay, providing information to a feed-forward correction of RF phase.

Wilcox, R.; Byrd, J. M.; Doolittle, L.; Huang, G.; Staples, J. W.

2010-01-02T23:59:59.000Z

132

Characteristics of a RF-Driven Ion Source for a Neutron Generator Used for Associated Particle Imaging  

SciTech Connect (OSTI)

We present recent work on a prototype compact neutron generator for associated particle imaging (API). API uses alpha particles that are produced simultaneously with neutrons in the deuterium-tritium ({sup 2}D({sup 3}T,n){sup 4}{alpha}) fusion reaction to determine the direction of the neutrons upon exiting the reaction. This method determines the spatial position of each neutron interaction and requires the neutrons to be generated from a small spot in order to achieve high spatial resolution. The ion source for API is designed to produce a focused ion beam with a beam spot diameter of 1-mm or less on the target. We use an axial type neutron generator with a predicted neutron yield of 10{sup 8} n/s for a 50 {mu}A D/T ion beam current accelerated to 80 kV. The generator utilizes an RF planar spiral antenna at 13.56 MHz to create a highly efficient inductively coupled plasma at the ion source. Experimental results show that beams with an atomic ion fraction of over 80% can be obtained while utilizing only 100 watts of RF power in the ion source. A single acceleration gap with a secondary electron suppression electrode is used in the tube. Experimental results from ion source testing, such as the current density, atomic ion fraction, electron temperature, and electron density will be discussed.

Wu Ying; Leung, K.-N. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Nuclear Engineering, University of California-Berkeley, Berkeley, CA 94720 (United States); Hurley, John P. [Special Technologies Laboratory, Santa Barbara, CA 93111 (United States); Ji Qing; Kwan, Joe [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

2009-03-10T23:59:59.000Z

133

Anaerobic Respiration on Tellurate and Other Metalloids in Bacteria from Hydrothermal Vent Fields in the Eastern Pacific Ocean  

Science Journals Connector (OSTI)

...tellurate, we noted first a drop in colony...source of reducing power for bioreduction...respiration at deep ocean hydrothermal vents...ER-V-6 is the first metavanadate-respiring...isolated from deep ocean hydrothermal vents...vent worms. The first evidence for selenite...bacteria from deep ocean hydrothermal vents...

Julius T. Csotonyi; Erko Stackebrandt; Vladimir Yurkov

2006-07-01T23:59:59.000Z

134

HOM Coupler Optimisation for the Superconducting RF Cavities in ESS  

E-Print Network [OSTI]

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.

Ainsworth, R; Calaga, R

2012-01-01T23:59:59.000Z

135

In situ RF/microwave remediation of soil experiment overview  

SciTech Connect (OSTI)

Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors are developing an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently, the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The authors objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants.

Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T. [Los Alamos National Lab., NM (United States); Ross, T.J. [Univ. of New Mexico, Albuquerque, NM (United States)

1995-09-01T23:59:59.000Z

136

A computer program for HVDC converter station RF noise calculations  

SciTech Connect (OSTI)

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.

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

137

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]

. scoparium and Q. stellata but not J. virginiana. All three species showed evidence of reduced temperature acclimation of respiration with progressive summer drought. Redistributed rainfall in J. virginiana increased respiration in midsummer compared...

Lindgren, Kourtnee Marr

2011-08-08T23:59:59.000Z

138

The Los Alamos VXI-based modular RF control system  

SciTech Connect (OSTI)

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.

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

139

The Los Alamos VXI-based modular RF control system  

SciTech Connect (OSTI)

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.

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

140

The MuCool Test Area and RF Program  

SciTech Connect (OSTI)

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.

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

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


141

Upgrading petroleum and petroleum fractions  

SciTech Connect (OSTI)

A method is described for neutralizing the organic naphthenic acids acidity present in petroleum and petroleum fractions to produce a neutralization number less than 1.0 whereby they are rendered suitable as lube oil feed stocks which consists essentially of treating the petroleum and petroleum fractions with a neutralizing amount of monoethanolamine to form an amine salt with the organic acids and then heating the thus-neutralized petroleum and petroleum fractions at a temperature at least about 25/sup 0/F greater than the boiling point of water and for a time sufficient to convert the amine salts to amides.

Ferguson, S.; Reese, D.D.

1988-06-21T23:59:59.000Z

142

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

E-Print Network [OSTI]

Photocathode RF Electron Gun S. Chattopadhyay, Y.J. Chen, D.PHOTOCATHODE RF ELECTRON GUN' S. Chnttopndhyny. Y.J. Chen (Photocathode RF Electron Gun S. Chattopadhyay, Y.I. Chen, D.

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

143

Mine waste contamination limits soil respiration rates: a case study using quantile regression  

E-Print Network [OSTI]

, the toxicity of heavy metals depends on soil acidity and organic matter because these factors strongly an environmental gradient. We quantified in situ soil respiration, pH, and heavy metal concentrations across a mine was limited with respect to both heavy metals and pH, and that both increased metals and increased acidity

Rilli, Matthias C.

144

Continuous measurements of soil respiration with and without roots in a ponderosa pine plantation in the  

E-Print Network [OSTI]

soil carbon www.elsevier.com/locate/agrformet Agricultural and Forest Meteorology 132 (2005) 212;sequestration and reduced CO2 efflux (Lal, 2004; Goh, 2004). Improved understanding of the mechanisms is necessary for evaluating the soil carbon budget on the global scale. Soil respiration has been extensively

Cohen, Ronald C.

145

Coherence analysis between respiration and heart rate variability using continuous wavelet transform  

Science Journals Connector (OSTI)

...followed by a high-pass filter (HPF), with...coherence) and error rates The distribution of the...the WTC between heart rate and respiration signals...Abramson Center for Medical Physics, Tel Aviv University...Computer Simulation Heart Rate physiology Humans Male...

2009-01-01T23:59:59.000Z

146

Soil respiration response to prescribed burning and thinning in mixed-conifer and hardwood  

E-Print Network [OSTI]

Soil respiration response to prescribed burning and thinning in mixed-conifer and hardwood forests (SRR) in a mixed-conifer and hardwood forest that had undergone various treatments from June to August 2003. The mixed-conifer forest, located in the Sierra Nevada Mountains of California, had been treated

North, Malcolm

147

Biogenic Carbon Cycling in the Upper Ocean: Effects of Microbial Respiration  

Science Journals Connector (OSTI)

...interactions (28). Region- to basin-scale estimates of community respiration...and South Atlantic Bight...Griffith et al 1990 So. Atlantic bight 4 19 134.4 278.6769 Coffin...Griffith et al 1990 So. Atlantic bight 4 18 55.2 124.7836 Griffith...

Richard B. Rivkin; Louis Legendre

2001-03-23T23:59:59.000Z

148

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

E-Print Network [OSTI]

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

Sachs, Julian P.

149

The ethanolic fermentation pathway supports respiration and lipid biosynthesis in tobacco pollen  

E-Print Network [OSTI]

The ethanolic fermentation pathway supports respiration and lipid biosynthesis in tobacco pollen. Previous work on pollen sugar metabolism showed that tobacco pollen carry out ef®cient ethanolic that the products of fermentation, acetaldehyde and ethanol, are further metabolised in a pathway that bypasses

Kuhlemeier, Cris

150

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

E-Print Network [OSTI]

ECG-Derived Respiration: Comparison and New Measures for Respiratory Variability Devy Widjaja1 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

151

Photosynthesis Respiration CH2O + O2 CO2 + H2O  

E-Print Network [OSTI]

Energy and life Photosynthesis Respiration CH2O + O2 CO2 + H2O hv Biomass CO2 + H2O CH2O + O2 ASSOCIATED WITH PHOTOSYNTHESIS) #12;ATP*: the "energy currency" of the cell *Adenosine triphospahte) PHOTOSYNTHESIS Light provides the energy for high energy electrons. The source of electrons is water OXIDATIVE

152

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

E-Print Network [OSTI]

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

Govindjee "Gov"

153

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

E-Print Network [OSTI]

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

Rose, Michael R.

154

Influence of the Radio-Frequency source properties on RF-based atom traps  

Science Journals Connector (OSTI)

We discuss the quality required for the RF source used to trap neutral atoms in RF-dressed potentials. We illustrate this discussion with experimental results obtained on a Bose-Einstein condensation experimen...

O. Morizot; L. Longchambon; R. Kollengode Easwaran…

2008-04-01T23:59:59.000Z

155

Advances in Broadband RF Sensing for Real-time Control of Plasma-Based Semiconductor Processing  

E-Print Network [OSTI]

to standard RF metrology. The system uses an antenna in the glow discharge to excite the bulk plasma identification of process conditions for standard RF sensing, and 99:5 correct identification of process

Grizzle, Jessy W.

156

E-Print Network 3.0 - accelerating rf station Sample Search Results  

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

by a 1.25-T -decay channel with phase-rotation via rf (to compress... to beam tests; Test 70-MHz rf cavity (+ 1.25-T magnet) 3 m from target; Characterize ... Source:...

157

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

Broader source: Energy.gov [DOE]

Purpose, Context, Meeting Process, and Agenda for MW and RF as Enabling Technologies for Advanced Manufacturing on July 25, 2012

158

COMPUTATIONAL MODELING OF MUONS PASSING THROUGH GAS PRESSURED RF CAVITIES  

E-Print Network [OSTI]

of muons passing through matter. PHYSICAL MODEL We start our study with a classical scattering of muonsCOMPUTATIONAL MODELING OF MUONS PASSING THROUGH GAS PRESSURED RF CAVITIES A. Samolov, A. Godunov, and to validate a technical design of these new accelerating facilities, accu- rate and comprehensive simulations

Godunov, Alexander L.

159

Feedback Configuration Tools for LHC Low Level RF  

SciTech Connect (OSTI)

The LHC Low Level RF System (LLRF) is a complex multi-VME crate system which is used to regulate the superconductive cavity gap voltage as well as to lower the impedance as seen by the beam through low latency feedback. This system contains multiple loops with several parameters to be set before the loops can be closed. In this paper, we present a suite of MATLAB based tools developed to perform the preliminary alignment of the RF stations and the beginnings of a closed loop model based alignment routine. We briefly introduce the RF system and in particular the base band (time domain noise based) network analyzer system built into the LHC LLRF. The main focus of this paper is the methodology of the algorithms used by the routines within the context of the overall system. Measured results are presented that validate the technique. Because the RF systems are located in a cavern 120 m underground in a location which is relatively un-accessible without beam and completely un-accessible with beam present or magnets are energized, these remotely operated tools are a necessity for the CERN LLRF team to maintain and tune their LLRF systems in a similar fashion as to what was done very successfully in PEP-II at SLAC.

Van Winkle, D.; Fox, J.; Mastorides, T.; Rivetta, C.; /SLAC; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /CERN

2009-12-16T23:59:59.000Z

160

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

E-Print Network [OSTI]

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 parameters. Due to the large value of the mean free path (MFP) the main mechanism of electron heating turns

Kaganovich, Igor

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


161

RF power potential of 45 nm CMOS technology  

E-Print Network [OSTI]

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 ...

Putnam, Christopher

162

Nb-Pb superconducting RF-gun TESLA-FEL Report 2005-09  

E-Print Network [OSTI]

Nb-Pb superconducting RF-gun TESLA-FEL Report 2005-09 J. Sekutowicz, J. Iversen, G. Kreps, W Sand Hill Road, Menlo Park, CA 94025, USA We report on the status of an electron RF-gun made of two superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead

163

Wi-fi backscatter: internet connectivity for RF-powered devices  

Science Journals Connector (OSTI)

RF-powered computers are small devices that compute and communicate using only the power that they harvest from RF signals. While existing technologies have harvested power from ambient RF sources (e.g., TV broadcasts), they require a dedicated gateway ... Keywords: backscatter, energy harvesting, internet of things, wireless

Bryce Kellogg, Aaron Parks, Shyamnath Gollakota, Joshua R. Smith, David Wetherall

2014-08-01T23:59:59.000Z

164

Multiband Antenna-Receiver Integration using an RF Multiplexer with Sensitivity-Constrained Design  

E-Print Network [OSTI]

S.M. Shajedul Hasan (hasan@vt.edu) Steven Ellingson (ellingson@vt.edu) RF Multiplexer Hasan be largely mitigated by: · Implementing design to be robust to variations RF Multiplexer Hasan / Ellingson #12;Motivation (2/2) Focus of this paper System Diagram of the prototype MMR RF Multiplexer Hasan

Ellingson, Steven W.

165

Multiband Antenna-Receiver Integration using an RF Multiplexer with Sensitivity-Constrained Design  

E-Print Network [OSTI]

S.M. Hasan and S. W. Ellingson Wireless at Virginia Tech RF Multiplexer Hasan / Ellingson ­ July 10 be largely mitigated by: 2/14 RF Multiplexer Hasan / Ellingson ­ July 10, 2008 RFIC from Motorola Research (2/2) Focus of this paper System Diagram of the prototype MMR 3/14 RF Multiplexer Hasan / Ellingson

Ellingson, Steven W.

166

Integration of LED chip within patch antenna geometry for hybrid FSO/RF communication  

E-Print Network [OSTI]

Integration of LED chip within patch antenna geometry for hybrid FSO/RF communication J. Liao, A mode communi- cation transmitter using a LED integrated within the geometry of a planar patch antenna the geometry of the patch antenna to create a miniaturised LED/RF package. The RF channel can either work

Huang, Zhaoran "Rena"

167

Design of RF Feed System for Standing-Wave Accelerator Structures  

SciTech Connect (OSTI)

We are investigating a standing wave structure with an rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

Neilson, Jeffrey; Tantawi, Sami; Dolgashev, Valery [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

2010-11-04T23:59:59.000Z

168

Continued Fraction Expansion Approaches to Discretizing Fractional Order Derivatives—an Expository Review  

Science Journals Connector (OSTI)

This paper attempts to present an expository review of continued fraction expansion (CFE) based discretization schemes for fractional order differentiators...

Yangquan Chen; Blas M. Vinagre; Igor Podlubny

2004-12-01T23:59:59.000Z

169

The Development of the Linac Coherent Light Source RF Gun  

SciTech Connect (OSTI)

The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of 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. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of the emittance compensation solenoid are discussed in Section 1.1.7. The novel feature of the LCLS solenoid is the embedded quadrupole correctors. The thermo-mechanical engineering of the LCLS gun is discussed in Section 1.1.8, and the cold and hot RF tests are described in Section 1.1.9. The results of this work are summarized and concluding remarks are given in Section 1.1.10.

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

2008-09-24T23:59:59.000Z

170

rf power system for thrust measurements of a helicon plasma source  

SciTech Connect (OSTI)

A rf power system has been developed, which allows the use of rf plasma devices in an electric propulsion test facility without excessive noise pollution in thruster diagnostics. Of particular importance are thrust stand measurements, which were previously impossible due to noise. Three major changes were made to the rf power system: first, the cable connection was changed from a balanced transmission line to an unbalanced coaxial line. Second, the rf power cabinet was placed remotely in order to reduce vibration-induced noise in the thrust stand. Finally, a relationship between transmission line length and rf was developed, which allows good transmission of rf power from the matching network to the helicon antenna. The modified system was tested on a thrust measurement stand and showed that rf power has no statistically significant contribution to the thrust stand measurement.

Kieckhafer, Alexander W.; Walker, Mitchell L. R. [Department of Aerospace Engineering, High-Power Electric Propulsion Laboratory, College of Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2010-07-15T23:59:59.000Z

171

Response of the carbon isotopic content of ecosystem, leaf, and soil respiration to meteorological and physiological driving factors in a  

E-Print Network [OSTI]

was negatively correlated with vpd (P CO2 exchange (NEE) was positively correlated with vpd (P CO2 uptake. Consistent temperatures cause isotopic enrichment of respired CO2. The significant driving parameters differed for d13 CR

Ehleringer, Jim

172

A liquid of fractional charges  

Science Journals Connector (OSTI)

... understanding. The first, the integral quantum Hall effect, has found practical application as a resistance standard as well as giving an improved value for the fine-structure constant a, ... value for the fine-structure constant a, a fundamental constant that describes the coupling of elementary particles to electromagnetic fields. The second, the fractional quantum Hall effect, manifests itself ...

Gerhard Fasol

1988-08-18T23:59:59.000Z

173

Performance of Magnesium Cathode in the S Band RF Gun  

SciTech Connect (OSTI)

In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of magnesium showed a dramatic improvement upon laser cleaning, increasing from 10{sup -5} to 4x10{sup -4} after two hours of cleaning. The spatial uniformity of emission also improved from a spot to spot variation of 10 to a variation of 2. Measurements with charges >1 nC indicate that the transient variation of the field due to the shielding effect of the electron in the vicinity of the cathode may play a critical role in the efficient extraction of electrons. Comprehensive theory that includes the electron emission in the presence of a time dependent Schottky effect and RF effects will be discussed.

Srinivasan-Rao, T.; /Brookhaven; Palmer, D.T.; /SLAC; Ben-Zvi, I.; /Brookhaven; Miller, R.H.; /SLAC; Wang, X.J.; Woodle, M.; /Brookhaven

2011-09-01T23:59:59.000Z

174

RF generation in the DARHT Axis-II beam dump  

SciTech Connect (OSTI)

We have occasionally observed radio-frequency (RF) electromagnetic signals in the downstream transport (DST) of the second axis linear induction accelerator (LIA) at the dual-axis radiographic hydrodynamic testing (DARHT) facility. We have identified and eliminated some of the sources by eliminating the offending cavities. However, we still observe strong RF in the range 1 GHz t0 2 GHz occurring late in the {approx}2-{micro}s pulse that can be excited or prevented by varying the downstream tune. The narrow frequency width (<0.5%) and near exponential growth at the dominant frequency is indicative of a beam-cavity interaction, and electro-magnetic simulations of cavity structure show a spectrum rich in resonances in the observed frequency range. However, the source of beam produced RF in the cavity resonance frequency range has not been identified, and it has been the subject of much speculation, ranging from beam-plasma or beam-ion instabilities to unstable cavity coupling.

Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

175

Structural properties of amorphous carbon thin films deposited by LF (100 kHz), RF (13.56 MHz), and pulsed RF (13.56 MHz) plasma CVD  

Science Journals Connector (OSTI)

Amorphous carbon thin films were deposited by LF (100 kHz), RF (13.56 MHz), and pulsed RF (13.56 MHz) plasma CVD with DC self-bias voltage of? ... properties of the deposited films in an asymmetric plasma reactor...

Dong-Sun Kim

2005-07-01T23:59:59.000Z

176

1 -SUBTIDAL 2 -INTERTIDAL RB ROCK UB UNCONSOLIDATED AB AQUATIC BED RF -REEF OW -OPEN WATER/ AB AQUATIC BED RF REEF RS ROCKY SHORE US -UNCONSOLIDATED  

E-Print Network [OSTI]

M - MARINE 1 - SUBTIDAL 2 - INTERTIDAL RB ­ ROCK UB ­ UNCONSOLIDATED AB ­ AQUATIC BED RF - REEF OW - OPEN WATER/ AB ­ AQUATIC BED RF­ REEF RS ­ ROCKY SHORE US - UNCONSOLIDATED BOTTOM BOTTOM Unknown Bottom ­ UNCONSOLIDATED AB ­ AQUATIC RF ­ REEF OW - OPEN WATER/ AB ­ AQUATIC RF­ REEF SB ­ STREAMBED RS - ROCKY US

Gray, Matthew

177

Listing Unique Fractional Factorial Designs  

E-Print Network [OSTI]

fractional factorial design. The defining contrast subgroup is {I, ABE, BCD, ACDE}. Suppose the 25?2 design is constructed by using defining words {BCD, ABE}. This design, shown in Fig. 4, has the runs {1,4,6,7,9,12,14,15} of Fig. 3. Taking the modulo-2 sum... in generating design catalogs . . . . . . . . . . . 5 I.2.1. Computational issues . . . . . . . . . . . . . . 5 I.2.2. Complicated designs . . . . . . . . . . . . . . 6 I.3. Research objectives and contributions . . . . . . . . . . 8 I.4. Organization...

Shrivastava, Abhishek Kumar

2011-02-22T23:59:59.000Z

178

Development of an RF Conditioning System for Charged-Particle Accelerators  

SciTech Connect (OSTI)

Charged-particle accelerators use various vacuum windows on their accelerating radio-frequency (RF) cavities to throughput very high RF power. Before being placed on the cavities, the windows should be cleaned, baked, and fully RF conditioned to prevent a poor vacuum from outgassing, as well as other forms of contamination. An example is the coaxial fundamental power coupler (FPC) with an annular alumina ceramic window for each of the 81 superconducting RF cavities in the Spallation Neutron Source (SNS) linear accelerator. The FPCs needed to be tested up to 650-kW peak in a traveling wave and 2.6 MW with standing wave peaks in 1.3 and 60 pulses/s at 805 MHz. In this paper, an Experimental-Physics-and-Industrial-Control-System-based RF conditioning system for the SNS RF test facility is presented. This paper summarizes the hardware and software design strategies, provides the results obtained, and describes the future research scope.

Kang, Yoon W [ORNL; Howlader, Mostofa [ORNL; Shajedul Hasan, Dr. S. M. [Virginia Polytechnic Institute and State University (Virginia Tech)

2008-01-01T23:59:59.000Z

179

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

DOE Patents [OSTI]

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.

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

2013-01-15T23:59:59.000Z

180

Production and decay properties of the 1.9-s isomeric state in {sup 261}Rf  

SciTech Connect (OSTI)

The 1.9-s isomeric state ({sup 261}Rf{sup b}) in {sup 261}Rf was directly populated in the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction. Alpha and spontaneous fission (SF) decays of {sup 261}Rf{sup b}, as well as the 68-s state {sup 261}Rf{sup a}, was investigated with a rotating wheel apparatus under low background conditions attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. An identification of {sup 261}Rf{sup b} was based on {alpha}-{alpha} correlations linking {alpha} decays of {sup 261}Rf{sup b} and its daughter {sup 257}No. The {alpha}-particle energy of {sup 261}Rf{sup b} was measured to be 8.52 {+-} 0.05 MeV. The half-life was determined to be 1.9 {+-} 0.4 s based on both 8.52-MeV {alpha} and SF decays. The {alpha} and SF branches are 0.27 {+-} 0.06 and 0.73 {+-} 0.06, respectively. The cross section for the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction is {sigma}({sup 261}Rf{sup b}) = 11 {+-} 2 nb at 95.1 MeV, which gives a cross-section ratio of {sigma}({sup 261}Rf{sup a})/{sigma}({sup 261}Rf{sup b}) = 1.1 {+-} 0.2.

Haba, H.; Kaji, D.; Kikunaga, H.; Kudou, Y.; Morimoto, K.; Morita, K.; Ozeki, K.; Sumita, T.; Yoneda, A.; Kasamatsu, Y.; Komori, Y.; Ooe, K.; Shinohara, A. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2011-03-15T23:59:59.000Z

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


181

Understanding fractional equivalence and the differentiated effects on operations with fractions  

E-Print Network [OSTI]

This study compared two representations for teaching fraction equivalence. It traced the implications of both representations on the student?s comprehension of fractions as well as their ability to perform operations with fractions...

Naiser, Emilie Ann

2005-02-17T23:59:59.000Z

182

RF heating systems evolution for the WEST project  

SciTech Connect (OSTI)

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.

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

183

E-Print Network 3.0 - aps linac rf Sample Search Results  

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

the gradient... - cient use of the linacs and the RF power, at the cost ... Source: Berg, J. Scott - Department of Physics, Brookhaven National Laboratory Collection: Physics 4...

184

TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities  

E-Print Network [OSTI]

TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun ..............................................................................................................................................................19 3.1. DESY GUN 2..................................................................................................................................................19 3.2. DESY GUN 4

185

E-Print Network 3.0 - argon rf plasma Sample Search Results  

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

- Princeton Plasma Physics Laboratory Collection: Plasma Physics and Fusion 6 REVERSE-VORTEX PLASMA STABILIZATION: EXPERIMENTS AND NUMERICAL SIMULATION Summary: -Frequency (RF)...

186

RF-driven advanced modes of ITER operation  

SciTech Connect (OSTI)

The impact of the Radio Frequency heating and current drive systems on the ITER advanced scenarios is analyzed by means of the CRONOS suite of codes for integrated tokamak modelling. As a first step, the code is applied to analyze a high power advanced scenario discharge of JET in order to validate both the heating and current drive modules and the overall simulation procedure. Then, ITER advanced scenarios, based on Radio Frequency systems, are studied on the basis of previous results. These simulations show that both hybrid and steady-state scenarios could be possible within the ITER specifications, using RF heating and current drive only.

Garcia, J.; Artaud, J. F.; Basiuk, V.; Decker, J.; Giruzzi, G.; Hawkes, N.; Imbeaux, F.; Litaudon, X.; Mailloux, J.; Peysson, Y.; Schneider, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Brix, M. [UKAEA/Euratom Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom)

2009-11-26T23:59:59.000Z

187

High-voltage R-F feedthrough bushing  

DOE Patents [OSTI]

Described is a multi-element, high voltage radio frequency bushing for transmitting rf energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

Grotz, G.F.

1982-09-03T23:59:59.000Z

188

Study of AC/RF properties of SRF ingot niobium  

SciTech Connect (OSTI)

In an attempt to correlate the performance of superconducting radiofrequency cavities made of niobium with the superconducting properties, we present the results of the magnetization and ac susceptibility of the niobium used in the superconducting radiofrequency cavity fabrication. The samples were subjected to buffer chemical polishing (BCP) surface and high temperature heat treatments, typically applied to the cavities fabrications. The analysis of the results show the different surface and bulk ac conductivity for the samples subjected to BCP and heat treatment. Furthermore, the RF surface impedance is measured on the sample using a TE011 microwave cavity for a comparison to the low frequency measurements.

Dhakal, Pashupati; Tsindlekht, Menachem I.; Genkin, Valery M.; Ciovati, Gianluigi; Myneni, Ganapati Rao

2013-09-01T23:59:59.000Z

189

Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds  

SciTech Connect (OSTI)

We consider an axisymmetric microwave cavity for an accelerator structure whose eigenfrequency for its second lowest TM-like axisymmetric mode is twice that of the lowest such mode, and for which the fields are asymmetric along its axis. In this cavity, the peak amplitude of the rf electric field that points into either longitudinal face can be smaller than the peak field which points out. Computations show that a structure using such cavities might support an accelerating gradient about 47% greater than that for a structure using similar single-mode cavities, without an increase in breakdown probability.

Kuzikov, S. V. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov Street, Nizhny Novgorod, 603950 (Russian Federation); Kazakov, S. Yu. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Jiang, Y. [Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States); Hirshfield, J. L. [Omega-P, Inc., 258 Bradley Street, New Haven, Connecticut 06510 (United States); Physics Department, Yale University, New Haven, Connecticut 06520-8120 (United States)

2010-05-28T23:59:59.000Z

190

THERMAL MODELING OF ION EXCHANGE COLUMNS WITH SPHERICAL RF RESIN  

SciTech Connect (OSTI)

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.

Lee, S.; King, W.

2009-12-30T23:59:59.000Z

191

Beam dynamics studies for transverse electromagnetic mode type rf deflectors  

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

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.

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

192

Glass antenna for RF-ion source operation  

DOE Patents [OSTI]

An antenna comprises a plurality of small diameter conductive wires disposed in a dielectric tube. The number and dimensions of the conductive wires is selected to improve the RF resistance of the antenna while also facilitating a reduction in thermal gradients that may create thermal stresses on the dielectric tube. The antenna may be mounted in a vacuum system using a low-stress antenna assembly that cushions and protects the dielectric tube from shock and mechanical vibration while also permitting convenient electrical and coolant connections to the antenna.

Leung, Ka Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA); Perkins, Luke T. (Plainsboro, NJ)

2000-01-01T23:59:59.000Z

193

Frequency and amplitude control for an experimental linac rf drive  

E-Print Network [OSTI]

, India Chair of Advisory Committee: Dr. S. P. Bhattacharyya, The Texas Accelerator Center (TAC) experimental linear accelerator uses a radio- frequency quadrupole (RFQ) to accelerate a 10 mA beam of H ions to 500 keV. It is to be used as an injector... to form a high-energy input beam for large circular accelerators. The pulsed beam will require 100 kW peak rf power at 473 MHz. To satisfy the beam dynamics requirements for particle acceleration and to minimize beam spill, the frequency of the source...

Atre, Mahesh Purushottam

1992-01-01T23:59:59.000Z

194

Capacitively coupled RF voltage probe having optimized flux linkage  

DOE Patents [OSTI]

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1999-02-02T23:59:59.000Z

195

Patterns of NPP, GPP, Respiration and NEP During Boreal Forest Succession  

SciTech Connect (OSTI)

We deployed a mesonet of year-round eddy covariance towers in boreal forest stands that last burned in ~1850, ~1930, 1964, 1981, 1989, 1998, and 2003 to understand how CO2 exchange changes during secondary succession.The strategy of using multiple methods, including biometry and micrometeorology, worked well. In particular, the three independent measures of NEP during succession gave similar results. A stratified and tiered approach to deploying eddy covariance systems that combines many lightweight and portable towers with a few permanent ones is likely to maximize the science return for a fixed investment. The existing conceptual models did a good job of capturing the dominant patterns of NPP, GPP, Respiration and NEP during succession. The initial loss of carbon following disturbance was neither as protracted nor large as predicted. This muted response reflects both the rapid regrowth of vegetation following fire and the prevalence of standing coarse woody debris following the fire, which is thought to decay slowly. In general, the patterns of forest recovery from disturbance should be expected to vary as a function of climate, ecosystem type and disturbance type. The NPP decline at the older stands appears related to increased Rauto rather than decreased GPP. The increase in Rauto in the older stands does not appear to be caused by accelerated maintenance respiration with increased biomass, and more likely involves increased allocation to fine root turnover, root metabolism, alternative forms of respiration, mycorrhizal relationships, or root exudates, possibly associated with progressive nutrient limitation. Several studies have now described a similar pattern of NEP following boreal fire, with 10-to-15 years of modest carbon loss followed by 50-to-100 years of modest carbon gain. This trend has been sufficiently replicated and evaluated using independent techniques that it can be used to quantify the likely effects of changes in boreal fire frequency and stand age structure on regional carbon balance.

Goulden, Michael L.; McMillan, Andrew; Winston, Greg; Rocha, Adrian; Manies, Kristen; Harden, Jennifer W.; Bond-Lamberty, Benjamin

2010-12-15T23:59:59.000Z

196

Coal fractionation by density for coking purposes  

Science Journals Connector (OSTI)

Scarce coal with good coking properties may be obtained by separating less valuable coal into different density fractions. The use of valuable fractions released in enrichment ensures optimal coking-batch composi...

S. G. Gagarin

2010-09-01T23:59:59.000Z

197

Influence of temperature on respiration of excised tissues from citrus seedlings  

E-Print Network [OSTI]

(C02 evolved and 02 absorbed, and the calculated RO and QIO) on tissues from sour orange seedlings revealed: 1) the relation between the amount of gas respired by hardened and unhardened plants and temperature was linear or slightly curvilinear... fluorescent and 12 100-w Modified nutrient solution: N (168 PPm N03 and 14 PPm NN4); Ca 200 ppm; K 78 ppm; P 31 ppm; Mg 48 ppm; 8 . 1 ppm; Mn 0. 5 ppm; Zn . 05 ppm; Cu . 02 ppm; Mo . 01 ppm; Fe 5 ppm (Chell 138). For specific control as the situations...

Peynado, Ascension

1970-01-01T23:59:59.000Z

198

Bacterial respiration.  

Science Journals Connector (OSTI)

...variety of redox car- riers, depending...to nongrowing cells, or 149, 332...cally) formate-hydrogen lyase activities...oxygen), the hydrogen-carrying limb...present in the hydrogen- and electron-carrying...demands on the cell vary. Third...oxidoreductase), through car- riers of similar...

B A Haddock; C W Jones

1977-03-01T23:59:59.000Z

199

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

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

RF RF [ICO] Name Last modified Size Description [DIR] Parent Directory - [ ] 0D8C3B68.pdf 08-May-2003 07:16 60K [ ] 0D8C3B68 Driver Kaptons.PDF 08-May-2003 07:16 69K [ ] 2002-10-28 - FMIT-3 Tuning to 78 MHZ.pdf 08-May-2003 07:16 425K [ ] FMIT 1 Crowb-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 1 Trans-cess.doc..pdf 08-May-2003 07:16 38K [ ] FMIT 1 Transformer Entry.pdf 08-May-2003 07:16 46K [ ] FMIT 2 Crowba-et access.pdf 08-May-2003 07:16 38K [ ] FMIT 2 Trans-cess.doc..pdf 08-May-2003 07:16 38K [ ] FMIT 2 Transformer Entry.pdf 08-May-2003 07:16 46K [ ] FMIT 3 Crowb-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 3 Trans-et Access.pdf 08-May-2003 07:16 38K [ ] FMIT 4 Crowb-et Access.pdf 08-May-2003 07:16 38K

200

Non-fusion applications of RF and microwave technology  

SciTech Connect (OSTI)

The processing of materials using rf and/or microwave power is a broad area that has grown significantly in the past few years. The authors have applied rf and microwave technology in the areas of ceramic sintering, plasma processing, and waste processing. The sintering of ceramics in the frequency range of 50 MHz-28 GHz has lead to unique material characteristics compared to materials that have been sintered conventionally. It has been demonstrated that sintering can be achieved in a variety of materials, including alumina, zirconia, silicon carbide, and boron carbide. In the area of plasma processing, progress has been made in the development and understanding of high density plasma sources, including inductively coupled plasma (ICP) sources. The effects of processing conditions on the ion energy distribution at the substrate surface (a critical processing issue) have been determined for a variety of process gases. The relationship between modeling and experiment is being established. Microwave technology has also been applied to the treatment of radioactive and chemical waste. The application of microwaves to the removal of contaminated concrete has been demonstrated. Details of these programs and other potential application areas are discussed.

Caughman, J.B.O.; Baity, F.W.; Bigelow, T.S.; Gardner, W.L.; Hoffman, D.J.; Forrester, S.C.; White, T.L.

1995-12-01T23:59:59.000Z

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


201

RF System Modeling for the CEBAF Energy Upgrade  

SciTech Connect (OSTI)

An RF system model, based on MATLAB/SIMULINK, has been developed for analyzing the basic characteristics of the low level RF (LLRF) control system being designed for the CEBAF 12 GeV Energy Upgrade. In our model, a typical passband cavity representation is simplified to in-phase and quadrature (I&Q) components. Lorentz Force and microphonic detuning are incorporated as a new quadrature carrier frequency (frequency modulation). Beam is also represented as in-phase and quadrature components and superpositioned with the cavity field vector. Signals pass through two low pass filters, where the cutoff frequency is equal to half of the cavity bandwidth, then they are demodulated using the same detuning frequency. Because only baseband I&Q signals are calculated, the simulation process is very fast when compared to other controller-cavity models. During the design process we successfully analyzed gain requirements vs. field stability for different superconducting cavity microphonic backgrounds and Lorentz Force coefficients. Moreover, we were able to evaluate different types of a LLRF system’s control algorithm: GDR (Generator Driven Resonator) and SEL (Self Excited Loop) [1] as well as klystron power requirements for different cavities and beam loads.

Tomasz Plawski, J. Hovater

2009-05-01T23:59:59.000Z

202

System studies of rf current drive for MST  

SciTech Connect (OSTI)

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.

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

203

Library for RF Interactions in Orbit Following Codes  

SciTech Connect (OSTI)

A new code-library has been developed to handle quasi-linear wave particle interactions in orbit following Monte Carlo codes, RFOF (RF interactions in Orbit Following codes). This library will enable a large number of orbit following codes to model fast ion acceleration during ICRF and Lower Hybrid heating. The RFOF consists of two main modules: one evaluates the resonance condition, the other the resulting RF acceleration. The resonance condition is tested at each step along the orbit and the location of the next upcoming resonance is predicted. When a particle reaches the resonance, a quasi-linear acceleration is calculated with a novel Monte Carlo technique that avoids the time-consuming evaluation of phase-space derivatives of the interaction strength. In RFOF the wave-particles interactions are assumed to be localized to a single point on the orbit. This is often valid for the ion cyclotron and lower hybrid frequency ranges, but prevents the treatment of bounce and precessional resonances. The RFOF has been developed within the European Task Force for Integrated Tokamak Modelling, enabling interaction between experts in different fields. As a result the code is designed with a simple and generic interface, with a minimum of assumptions on e.g. the geometry. Successful integration with the two orbit following codes, ASCOT and SPOT, has already been demonstrated.

Johnson, T.; Hellsten, T.; Hoeoek, L. J. [Association EURATOM-VR, rary for RF Interactions in Orbit Following CoKTH (Sweden); Salmi, A. [Association Euratom - TEKES, Aalto University (Finland); Steinbrecher, G. [Association EURATOM-MEdC, Univ. of Craiova (Romania); Eriksson, L.-G. [European Commission, Research Directorate General (Belgium); Schneider, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

2011-12-23T23:59:59.000Z

204

R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-State Studies, Preliminary FEL-1 Time-Dependent Studies, and Preliminary Layout Option Investigation  

E-Print Network [OSTI]

R&D Requirements, RF Gun Mode Studies, FEL-2 Steady-Stateinitial studies of the RF gun mode-coupling and potentialas more novel rf photocathode gun configurations – these may

2005-01-01T23:59:59.000Z

205

Particle-In-Cell/Monte Carlo Simulation of Ion Back BomBardment in a High Average Current RF Photo-Gun  

E-Print Network [OSTI]

High Average Current RF Photo-Gun J. Qiang Lawrence Berkeleycurrent radio-frequency (RF) photo-gun using a particle-in-of high average current RF photo-guns have been proposed or

Qiang, J.

2010-01-01T23:59:59.000Z

206

Permanent-magnet helicon sources and arrays: a new type of rf plasma Francis F. Chena)  

E-Print Network [OSTI]

Permanent-magnet helicon sources and arrays: a new type of rf plasma Francis F. Chena) and Humberto mechanism of RF coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small

Chen, Francis F.

207

Permanent-magnet helicon sources and arrays: A new type of rf plasmaa... Francis F. Chenb  

E-Print Network [OSTI]

Permanent-magnet helicon sources and arrays: A new type of rf plasmaa... Francis F. Chenb mechanism of rf coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small

Chen, Francis F.

208

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. Schreiber. For this, an rf-gun based photoinjec- tor was installed late 1998 and is in operation since then gun [4] to match the beam charcteristics as close as pos- sible to the TESLA proposal. It is able

209

Studies of TTF RF Photocathode Gun using acoustic sensors J. Nelson and M. Ross  

E-Print Network [OSTI]

1 Studies of TTF RF Photocathode Gun using acoustic sensors J. Nelson and M. Ross SLAC November 27 RF high voltage breakdown locations in the photocathode gun system. It is not known if the acoustic gun [4] to locate its breakdown events during operation with a pulse length of 300µs and a pulse

210

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 was produced by a sub-harmonic in- jector using a thermionic gun, a buncher cavity, and one standard Linear Collider, a laser driven rf gun has been de- veloped and been brought in operation late fall 1998

211

Improved wireless security for GMSK-based devices using RF fingerprinting  

Science Journals Connector (OSTI)

Gaussian minimum shift keying (GMSK) is employed in current global system for mobile (GSM) networks and remains a viable option for future wireless systems. Physical layer (PHY) security is demonstrated using RF fingerprints from ... Keywords: GMSK, GSM networks, Gaussian minimum shift keying, MDA, PHY security, RF fingerprinting, SEI, authentication, electronic security, multiple discriminant analysis, physical layer, specific emitter identification, wireless networks, wireless security

Donald R. Reising; Michael A. Temple; Michael J. Mendenhall

2010-03-01T23:59:59.000Z

212

Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas  

E-Print Network [OSTI]

Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas Siqi Luo to the ambient air. The atmospheric-pressure plasma is then maintained with the 13.56 MHz rf power. Using of atmospheric-pressure air plasmas The kinetics of reactions and transitions in atmospheric- pressure air

Scharer, John E.

213

Tore Supra LH transmitter upgrade, a new RF driver for the power spectrum  

SciTech Connect (OSTI)

New real time tools have been developed for testing new 700kW/3.7GHz/CW klystrons and for the operations on very long plasma shots. After the commissioning of the 18 series tubes on the high power test bed facility, the installation of the first 8 klystrons in the Tore Supra transmitter and the adjustment tests on load, this upgrade work has been materialized during the last 2010 campaign by a successful operation on the Full Active Multijunction (FAM) C3 antenna, with new performances: 3.5MW/40s on plasma. The RF output power control in amplitude and phase has been improved for a better control of the wave spectrum launched into the plasma. The new klystrons have no modulating anode and the high cathode voltage must be adjusted with the RF input power in order to optimize the RF output power with a minimization of the thermal power losses in the collector. A new phase correction, depending on the 3 RF output power ranges used, has been introduced. The improvements made in 2009 and 2010 on the generic phase loop and the procedures used during the real time tests of the RF transfer functions in amplitude and phase are detailed below. All RF measurements systems, RF safety systems and the RF calibration procedures have been revised in order to have the best consistency, reproducibility and with a measurement error against the calorimetry measurement lower than 10%.

Berger-By, G.; Achard, J.; Armitano, A.; Bouquey, F.; Corbel, E.; Delpech, L.; Ekedahl, A.; Lombard, G.; Magne, R.; Mollard, P.; Pagano, M.; Prou, M.; Samaille, F.; Volpe, D.; Volpe, R. [CEA IRFM, F-13108 Saint-Paul-Lez-Durance (France)

2011-12-23T23:59:59.000Z

214

Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna  

SciTech Connect (OSTI)

RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M. [LPP/ERM-KMS, Association EURATOM-Belgian State, Brussels (Belgium); Wooldridge, E. [EURATOM/CCFE Fusion Association, Culham Science Centre (United Kingdom)

2011-12-23T23:59:59.000Z

215

High tunability barium strontium titanate thin films for rf circuit applications  

E-Print Network [OSTI]

High tunability barium strontium titanate thin films for rf circuit applications N. K. Pervez,a) P) Large variations in the permittivity of rf magnetron sputtered thin-film barium strontium titanate have/cm. © 2004 American Institute of Physics. [DOI: 10.1063/1.1818724] Barium strontium titanate (BST) is a solid

York, Robert A.

216

Radar Vibrometry: Investigating the Potential of RF microwaves to measure vibrations  

E-Print Network [OSTI]

Radar Vibrometry: Investigating the Potential of RF microwaves to measure vibrations K A Tsolis, C classification process. Recent research on vibrometry, the process of conducting vibration measurements. With this study we make a primary investigation of the capabilities of RF radar systems to measure vibrations. We

Haddadi, Hamed

217

Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control  

E-Print Network [OSTI]

systems, RF powered systems present a new challenge for the energy management. A WSN node repeatedly in the capacitor. Therefore, we implemented an adaptive duty cycle control scheme that is optimized for RF energy but is not affected by weather and so it is more stable than solar and wind power. Almost all energy management

Tentzeris, Manos

218

Analytical Model for RF Power Performance of Deeply Scaled CMOS Devices  

E-Print Network [OSTI]

predictions from the model with measured load-pull data on 45 nm CMOS devices. II. MODEL DESCRIPTION The power by the load resistor. Fig. 1: Circuit diagram of a reduced conduction angle RF power amplifier. Fig. 2Analytical Model for RF Power Performance of Deeply Scaled CMOS Devices Usha Gogineni1 , JesĂşs del

del Alamo, JesĂşs A.

219

Study of high pressure gas filled RF cavities for muon collider  

E-Print Network [OSTI]

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.

Yonehara, Katsuya

2015-01-01T23:59:59.000Z

220

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

E-Print Network [OSTI]

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

Stancil, Daniel D.

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


221

A Time-AverageModel of the RF PlasmaSheath Demetre J, Economou.3  

E-Print Network [OSTI]

A Time-AverageModel of the RF PlasmaSheath Demetre J, Economou.3 Department of Chemical Engineering 97077 Richard C. Alkire* Department of Chemical Engineering, University of Illinois, Urbana, Illinois 6t801 ABSTRACT A time-average model of the RF plasma sheath was developed. The ion "fluid" equations

Economou, Demetre J.

222

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

DOE Patents [OSTI]

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.

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

223

Studies on the Matching Network of the High Power Radio Frequency Transmitter for the NBI RF Ion Source  

Science Journals Connector (OSTI)

A radio frequency (RF) driven ion source has been developed at ASIPP (Institute of Plasma Physics, CAS) for the neutral beam injector with a 1 MHz, 25 kW RF power supply system. The paper describes the studies pe...

Renxue Su; Zhimin Liu; Yahong Xie; Yuqian Chen; Yuming Gu…

2014-08-01T23:59:59.000Z

224

The external magnetic field dependence of RF splitting of57Fe hyperfine lines. NMR + Mössbauer double resonance experiment  

Science Journals Connector (OSTI)

We present the results of an experimental investigation of a RF splitting of57Fe hyperfine lines in the regime of NMR and Mössbauer ... have been performed as a function of RF field intensity and static magnetic

F. G. Vagizov

1995-01-01T23:59:59.000Z

225

HEAT TRANSFER ANALYSIS FOR FIXED CST AND RF COLUMNS  

SciTech Connect (OSTI)

In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, transient and steady state two-dimensional heat transfer models have been constructed for columns loaded with cesium-saturated crystalline silicotitanate (CST) or spherical Resorcinol-Formaldehyde (RF) beads and 6 molar sodium tank waste supernate. Radiolytic decay of sorbed cesium results in heat generation within the columns. The models consider conductive heat transfer only with no convective cooling and no process flow within the columns (assumed column geometry: 27.375 in ID with a 6.625 in OD center-line cooling pipe). Heat transfer at the column walls was assumed to occur by natural convection cooling with 35 C air. A number of modeling calculations were performed using this computational heat transfer approach. Minimal additional calculations were also conducted to predict temperature increases expected for salt solution processed through columns of various heights at the slowest expected operational flow rate of 5 gpm. Results for the bounding model with no process flow and no active cooling indicate that the time required to reach the boiling point of {approx}130 C for a CST-salt solution mixture containing 257 Ci/liter of Cs-137 heat source (maximum expected loading for SCIX applications) at 35 C initial temperature is about 6 days. Modeling results for a column actively cooled with external wall jackets and the internal coolant pipe (inlet coolant water temperature: 25 C) indicate that the CST column can be maintained non-boiling under these conditions indefinitely. The results also show that the maximum temperature of an RF-salt solution column containing 133 Ci/liter of Cs-137 (maximum expected loading) will never reach boiling under any conditions (maximum predicted temperature without cooling: 88 C). The results indicate that a 6-in cooling pipe at the center of the column provides the most effective cooling mechanism for reducing the maximum temperature with either ion exchange material. Sensitivity calculations for the RF resin porosity, the ambient external column temperature, and the cooling system configuration were performed under the baseline conditions to assess the impact of these parameters on the maximum temperatures. It is noted that the cooling mechanism at the column boundary (forced versus natural convection) and the cooling system configuration significantly impact the maximum temperatures. The analysis results provide quantitative information associated with process temperature control requirements and management of the SCIX column.

Lee, S

2007-10-17T23:59:59.000Z

226

Cerenkov Radiator Driven by a Superconducting RF Electron Gun  

SciTech Connect (OSTI)

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.

Poole, B R; Harris, J R

2011-03-07T23:59:59.000Z

227

A new microphonics measurement method for superconducting RF cavities  

SciTech Connect (OSTI)

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.

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

2014-09-01T23:59:59.000Z

228

RF Heating in Electron Cyclotron Resonance Ion Sources  

SciTech Connect (OSTI)

ECRIS-Electron Cyclotron Resonance Ion Sources are able to feed accelerators with intense currents of highly charged ions. In ECRIS a high density-high temperature plasma is generated by means of the Electron Cyclotron Resonance Heating inside a B-min, MHD stable trap. The state of the art about the principal heating mechanisms will be given. The paper will specially discuss the most critical and still open issues concerning the influence of the magnetic field and of the RF frequency on the plasma heating, as well as the impact of possible non-linear pumping wave-to-plasma interactions. The contribution of INFN-LNS will be specifically underlined. A short review on the future perspectives for the design of new generation ion sources will be given in conclusion.

Mascali, D. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria, 6 - 95125 Catania (Italy); Gammino, S.; Celona, L.; Ciavola, G. [INFN - LNS, via S. Sofia 62, 95123 Catania (Italy)

2011-12-23T23:59:59.000Z

229

RF and structural characterization of new SRF films  

SciTech Connect (OSTI)

In the past years, energetic vacuum deposition methods have been developed in different laboratories to improve Nb/Cu technology for superconducting cavities. Jefferson Lab is pursuing energetic condensation deposition via Electron Cyclotron Resonance. As part of this study, the influence of the deposition energy on the material and RF properties of the Nb thin film is investigated. The film surface and structure analyses are conducted with various techniques like X-ray diffraction, Transmission Electron Microscopy, Auger Electron Spectroscopy and RHEED. The microwave properties of the films are characterized on 50 mm disk samples with a 7.5 GHz surface impedance characterization system. This paper presents surface impedance measurements in correlation with surface and material characterization for Nb films produced on copper substrates with different bias voltages and also highlights emerging opportunities for developing multilayer SRF films with a new deposition system.

A.-M. Valente-Feliciano,H. L. Phillips,C. E. Reece,X. Zhao,D. Gu,R. Lukaszew,B. Xiao,K. Seo

2009-09-01T23:59:59.000Z

230

RF Design Optimization for New Injector Cryounit at CEBAF  

SciTech Connect (OSTI)

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.

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

2013-06-01T23:59:59.000Z

231

National RF Test Facility as a multipurpose development tool  

SciTech Connect (OSTI)

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.

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

232

Structurefunction of the Na/H Exchanger Regulatory Factor (NHE-RF) 2199 The Journal of Clinical Investigation  

E-Print Network [OSTI]

, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710 representing full-length NHE-RF as well as truncated and mutant forms of NHE-RF were deter- mined using/H exchanger activity that is not regulated by PKA. NHE-RF in the presence of ATP and Mg but not PKA, in

Hall, Randy A

233

Isotope/element fractionation during surface adsorption  

Science Journals Connector (OSTI)

The adsorption of ions onto mineral surfaces accompanies isotope/element fractionation in planets and asteroids. A model based on simple classical physics is presented to predict these fractionations. The agreement between the experimentally observed isotope/element ratios and their predicted values is found to be excellent. This fractionation can be demonstrated experimentally in advanced physics laboratories using macroscopic particles. The success of the model shows students that even a very complex naturally occurring process can be explained quantitatively with simple physics.

Gamini Seneviratne; Asiri Nanayakkara

2004-01-01T23:59:59.000Z

234

Accelerator dynamics of a fractional kicked rotor  

E-Print Network [OSTI]

It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum localization saturates this acceleration, such that the average value of the orbital momentum can be a direct current and the system behaves like a ratchet. The classical counterpart is a nonlinear kicked rotor with absorbing boundary conditions.

A. Iomin

2006-09-14T23:59:59.000Z

235

Nonlinear time-fractional dispersive equations  

E-Print Network [OSTI]

In this paper we study some cases of time-fractional nonlinear dispersive equations (NDEs) involving Caputo derivatives, by means of the invariant subspace method. This method allows to find exact solutions to nonlinear time-fractional partial differential equations by separating variables. We first consider a third order time-fractional NDE that admits a four-dimensional invariant subspace and we find a similarity solution. We also study a fifth order NDE. In this last case we find a solution involving Mittag-Leffler functions. We finally observe that the invariant subspace method permits to find explicit solutions for a wide class of nonlinear dispersive time-fractional equations.

P. Artale Harris; R. Garra

2014-10-29T23:59:59.000Z

236

Mesoscopic Fractional Quantum in Soft Matter  

E-Print Network [OSTI]

Soft matter (e.g., biomaterials, polymers, sediments, oil, emulsions) has become an important bridge between physics and diverse disciplines. Its fundamental physical mechanism, however, is largely obscure. This study made the first attempt to connect fractional Schrodinger equation and soft matter physics under a consistent framework from empirical power scaling to phenomenological kinetics and macromechanics to mesoscopic quantum mechanics. The original contributions are the fractional quantum relationships, which show Levy statistics and fractional Brownian motion are essentially related to momentum and energy, respectively. The fractional quantum underlies fractal mesostructures and many-body interactions of macromolecules in soft matter and is experimentally testable.

W Chen

2005-05-09T23:59:59.000Z

237

Study on the Respirable Particulate Matter Generated from the Petroleum Coke and Coal Mixed-Fired CFB Boiler  

Science Journals Connector (OSTI)

The dust generated from the fuel combustion is one of the important sources for air pollution. This paper has made a comprehensive research on the particulate matter generated from the petroleum coke and coal mixed-fired circulating fluidized bed (CFB) ... Keywords: petroleum coke, respirable particulate matter, air pollution, circulating fluidized bed boiler

Yan Ma; Hao Bai; Lihua Zhao; Yang Ma; Daqiang Cang

2010-12-01T23:59:59.000Z

238

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

E-Print Network [OSTI]

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

Gilli, Adrian

239

Raman Spectroscopy—An Innovative and Versatile Tool To Follow the Respirational Activity and Carbonate Biomineralization of Important Cave Bacteria  

Science Journals Connector (OSTI)

Raman Spectroscopy—An Innovative and Versatile Tool To Follow the Respirational Activity and Carbonate Biomineralization of Important Cave Bacteria ... (11) Bacterial calcium carbonate formation is applied in contaminated soil and groundwater remediation,(12) the protection and repair of concrete and cement structures,(13) and the conservation of building stone and statuary. ...

Robert Keiner; Torsten Frosch; Stefan Hanf; Anna Rusznyak; Denise M. Akob; Kirsten Küsel; Jürgen Popp

2013-08-23T23:59:59.000Z

240

Studies on Respiration and 11?-Hydroxylation of Deoxycorticosterone in Mitochondria and Intact Cells Isolated from the Snell Adrenocortical Carcinoma 494  

Science Journals Connector (OSTI)

...from adrenals of normal adult male rats (P2C) and the Snell adrenocortical carcinoma...respiration and 11beta-hydroxylation in P2C while alpha-glycerol phosphate did this...levels in P2T were lower than were those in P2C, which partly accounts for the very low...

Fernand G. Péron; Ajai Haksar; Ming-te Lin; David Kupfer; William Robidoux, Jr.; Gary Kimmel; E. Bedigian

1974-10-01T23:59:59.000Z

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


241

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

SciTech Connect (OSTI)

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.

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

242

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

SciTech Connect (OSTI)

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.

Larsen, R

2009-10-17T23:59:59.000Z

243

On using an adaptive neural network to predict lung tumor motion during respiration for radiotherapy applications  

SciTech Connect (OSTI)

In this study we address the problem of predicting the position of a moving lung tumor during respiration on the basis of external breathing signals--a technique used for beam gating, tracking, and other dynamic motion management techniques in radiation therapy. We demonstrate the use of neural network filters to correlate tumor position with external surrogate markers while simultaneously predicting the motion ahead in time, for situations in which neither the breathing pattern nor the correlation between moving anatomical elements is constant in time. One pancreatic cancer patient and two lung cancer patients with mid/upper lobe tumors were fluoroscopically imaged to observe tumor motion synchronously with the movement of external chest markers during free breathing. The external marker position was provided as input to a feed-forward neural network that correlated the marker and tumor movement to predict the tumor position up to 800 ms in advance. The predicted tumor position was compared to its observed position to establish the accuracy with which the filter could dynamically track tumor motion under nonstationary conditions. These results were compared to simplified linear versions of the filter. The two lung cancer patients exhibited complex respiratory behavior in which the correlation between surrogate marker and tumor position changed with each cycle of breathing. By automatically and continuously adjusting its parameters to the observations, the neural network achieved better tracking accuracy than the fixed and adaptive linear filters. Variability and instability in human respiration complicate the task of predicting tumor position from surrogate breathing signals. Our results show that adaptive signal-processing filters can provide more accurate tumor position estimates than simpler stationary filters when presented with nonstationary breathing motion.

Isaksson, Marcus; Jalden, Joakim; Murphy, Martin J. [Department of Electrical Engineering, Stanford University, Stanford, California 94036 (United States); Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

2005-12-15T23:59:59.000Z

244

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

SciTech Connect (OSTI)

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.

Chung, M.; et al.

2013-10-01T23:59:59.000Z

245

Development of an L-Band RF Electron Gun for SASE in the Infrared Region  

SciTech Connect (OSTI)

We conduct research on Self-Amplified Spontaneous Emission (SASE) in the infrared region using the 40 MeV, 1.3 GHz L-band linac of Osaka University. The linac equipped with a thermionic electron gun can accelerate a high-intensity single-bunch beam though its normalized emittance is high. In order to advance the research on SASE, we have begun development of an RF gun for the L-band linac in collaboration with KEK. We will report conceptual design of the RF gun and present the status of development of another RF gun for STF at KEK.

Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayano, Hitoshi; Urakawa, Junji [Accelerator Laboratory, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

2010-02-03T23:59:59.000Z

246

Arc Detection and Interlock Module for the PEP II Low Level RF System  

SciTech Connect (OSTI)

A new arc detection and interlock generating module for the SLAC PEP-II low-level RF VXI-based system has been developed. The system is required to turn off the RF drive and high voltage power supply in the event of arcing in the cavity windows, klystron window, or circulator. Infrared photodiodes receive arc signals through radiation resistant optical fibers. Gain and bandwidth are selectable for each channel to allow tailoring response. The module also responds to interlock requests from other modules in the VXI system and communicates with the programmable logic controller (PLC) responsible for much of the low-level RF system's interlock functionality.

Tighe, R.; /SLAC

2011-08-31T23:59:59.000Z

247

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

SciTech Connect (OSTI)

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.

Kwan, Joe; Ji, Qing

2014-05-20T23:59:59.000Z

248

Operation of a planar-electrode ion trap array with adjustable RF electrodes  

E-Print Network [OSTI]

One path to scaling-up trapped atomic ions for large-scale quantum computing and simulation is to create a two-dimensional array of ion traps in close proximity to each other. A method to control the interactions between nearest neighboring ions is demonstrated and characterized here, using an adjustable radio-frequency (RF) electrode between trapping sites. A printed circuit board planar-electrode ion trap is demonstrated, trapping laser-cooled $^{40}$Ca$^+$ ions. RF shuttling and secular-frequency adjustment are shown as a function of the power applied to the addressed RF electrode. The trapped ion's heating rate is measured via a fluorescence recooling method.

Muir Kumph; Philip Holz; Kirsten Langer; Michael Niedermayr; Michael Brownnutt; Rainer Blatt

2014-02-04T23:59:59.000Z

249

Inverse Problems for Fractional Diffusion Equations  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.5.3 Derivation of fractional difiusion equations . . . . . . . . . . . 12 1.6 Fractional calculus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.7 Mittag-Le?er function . . . . . . . . . . . . . . . . . . . . . . . . . . 14 1... point theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3 Volterra equation of the second kind . . . . . . . . . . . . . . . . . . 6 1.4 Classical difiusion equations . . . . . . . . . . . . . . . . . . . . . . . 6 1.4.1 Derivation...

Zuo, Lihua

2013-06-21T23:59:59.000Z

250

Fractional Zaslavsky and Henon Discrete Maps  

E-Print Network [OSTI]

This paper is devoted to the memory of Professor George M. Zaslavsky passed away on November 25, 2008. In the field of discrete maps, George M. Zaslavsky introduced a dissipative standard map which is called now the Zaslavsky map. G. Zaslavsky initialized many fundamental concepts and ideas in the fractional dynamics and kinetics. In this paper, starting from kicked damped equations with derivatives of non-integer orders we derive a fractional generalization of discrete maps. These fractional maps are generalizations of the Zaslavsky map and the Henon map. The main property of the fractional differential equations and the correspondent fractional maps is a long-term memory and dissipation. The memory is realized by the fact that their present state evolution depends on all past states with special forms of weights.

Vasily E. Tarasov

2011-07-26T23:59:59.000Z

251

BEAM-BASED ALIGNMENT OF TTF RF-GUN USING V-CODE* W. Beinhauer, R. Cee, W. Koch, M. Krassilnikov  

E-Print Network [OSTI]

BEAM-BASED ALIGNMENT OF TTF RF-GUN USING V-CODE* W. Beinhauer, R. Cee, W. Koch, M. Krassilnikov , A), located after the RF- gun cavity, showed non-zero readings. Moreover the readings depended on RF-power, RF-phase and primary and secondary solenoid currents. This effect could be ex- plained by misalignments of the gun

252

Superconducting laser photocathode RF gun at BNL | U.S. DOE Office of  

Office of Science (SC) Website

Superconducting laser photocathode RF Superconducting laser photocathode RF gun at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Superconducting laser photocathode RF gun at BNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Superconducting laser photocathode RF gun Developed at: Brookhaven National Laboratory (BNL), New York and Advanced Energy Systems,

253

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-Print Network [OSTI]

Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

Lee, Dong Seup

2014-01-01T23:59:59.000Z

254

RF phase modulation of optical signals and optical/electrical signal processing  

E-Print Network [OSTI]

Analog RF phase modulation of optical signals has been a topic of interest for many years, mainly focusing on Intensity Modulation Direct Detection (IMDD). The virtues of coherent detection combined with the advantages of ...

Andrikogiannopoulos, Nikolas I

2006-01-01T23:59:59.000Z

255

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

SciTech Connect (OSTI)

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.

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

256

A CW normal-conductive RF gun for free electron laser and energy recovery linac applications  

E-Print Network [OSTI]

Todd, State-of-the art electron guns and injector de- signs,7] Summary of working group on guns and injectors, 41st Ad-A CW normal-conductive RF gun for free electron laser and

Baptiste, Kenneth

2009-01-01T23:59:59.000Z

257

Analysis of slice transverse emittance evolutioin in a photocathode RF gun  

E-Print Network [OSTI]

evolution at 1 nC for the LCLS gun including the solenoidevolution at 1 nC for the LCLS gun including the solenoidevolution in a photocathode RF gun Zhirong Huang, Yuantao

Huang, Zhirong

2009-01-01T23:59:59.000Z

258

Experimental evaluation of 350 MHz RF accelerator windows for the low energy demonstration accelerator  

SciTech Connect (OSTI)

Radio frequency (RF) windows are historically a point where failure occurs in input power couplers for accelerators. To obtain a reliable, high-power, 350 MHz RF window for the Low Energy Demonstration Accelerator (LEDA) project of the Accelerator Production of Tritium program, RF windows prototypes from different vendors were tested. Experiments were performed to evaluate the RF windows by the vendors to select a window for the LEDA project. The Communications and Power, Inc. (CPI) windows were conditioned to 445 kW in roughly 15 hours. At 445 kW a window failed, and the cause of the failure will be presented. The English Electronic Valve, Inc. (EEV) windows were conditioned to 944 kW in 26 hours and then tested at 944 kW for 4 hours with no indication of problems.

Cummings, K.; Rees, D.; Roybal, W. [and others

1997-09-01T23:59:59.000Z

259

E-Print Network 3.0 - active rf pulse Sample Search Results  

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

that the duty ratios of the pulse are kept large for small input. Then, an RF pulse train is generated by mixing... the modulated envelope with the phase modulated carrier. The...

260

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

E-Print Network [OSTI]

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...

Armendariz, Marcelino

2012-02-14T23:59:59.000Z

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


261

Characteristics of Hydrogen Negative Ion Source with FET based RF System  

SciTech Connect (OSTI)

Characteristics of radio frequency (RF) plasma production were investigated using a FET inverter power supply as a RF generator. High density hydrogen plasma was obtained using an external coil wound a cylindrical ceramic tube (driver region) with RF frequency of lower than 0.5 MHz. When an axial magnetic field around 10 mT was applied to the driver region, an electron density increased drastically and attained to over 10{sup 19} m{sup -3} in the driver region. Effect of the axial magnetic field in driver and expansion region was examined. Lower gas pressure operation below 0.5 Pa was possible with higher RF frequency. H{sup -} density in the expansion region was measured by using laser photo-detachment system. It decreased as the axial magnetic field applied, which was caused by the increase of energetic electron from the driver.

Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N. [Graduate School of Engineering, Tohoku University, Aoba-yama, Sendai, 980-8579 (Japan); Tsumori, K.; Takeiri, Y. [National Institute for Fusion Science, Oroshi-cho, Toki, 509-5292 (Japan)

2011-09-26T23:59:59.000Z

262

RF sputtering for controlling dihydride and monohydride bond densities in amorphous silicon hydride  

DOE Patents [OSTI]

A process is described for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicone 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 solicone hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

Jeffery, F.R.; Shanks, H.R.

1980-08-26T23:59:59.000Z

263

PRODUCTION OF LARGE VOLUME CYLINDRICAL RF PLASMA USING CIRCULAR MAGNETIC LINE CUSP FIELD  

Science Journals Connector (OSTI)

A large volume cylindrical rf (radio frequency) plasma source using a circular magnetic line cusp field has been developed for various large scale plasma processings. In this type of plasma source, a capacitively coupled 13.56 \\{MHz\\} rf plasma is produced in a circular magnetic line cusp field. Two versions of the plasma source have been constructed and tasted. The first version has a pair of peripheral rf electrodes placed outside the ionization chamber and is suitable for preparing a large volume uniform plasma. This plasma source can attain uniformity within 107 cm?3 over a 30 cm diameter region. The other which is provided with parallel doughnut plate electrodes forming part of the chamber wall serves as a high current plasma source, where the electron density is proportional to the rf power and equal to 7 × 109 cm?3 for 500 W.

K. YAMAUCHI; M. SHIBAGAKI; A. KONO; K. TAKAHASHI; T. SHEBUYA; E. YABE; K. TAKAYAMA

1993-01-01T23:59:59.000Z

264

Characteristics of single and dual radio-frequency (RF) plasma sheaths  

Science Journals Connector (OSTI)

The characteristics of radio-frequency (RF) plasma sheaths have been topics of much scientific ... in the study of physical phenomena in dusty plasmas. The sheaths behave special properties under various ... as c...

Zhong-ling Dai; You-nian Wang

2006-06-01T23:59:59.000Z

265

The analysis of conductive solid samples by r.f. capacitively coupled plasma at atmospheric pressure  

Science Journals Connector (OSTI)

A radiofrequency capacitively coupled plasma (rf CCP) with tip-ring electrode geometry has been used for the analysis of Al, Co, Cr, Cu, Mn, Mo, Ni, and V in low and medium alloyed steel. The sample is used as...

Sorin D. Anghel; Tiberiu Frentiu…

1996-06-01T23:59:59.000Z

266

E-Print Network 3.0 - average current rf Sample Search Results  

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

management estimates the channel upon a frame recep- tion. MIMO... MHz bandwidth. 6.2 Simulation Results We compare the average energy per bit of RF chain management... measure...

267

The splitting of hyperfine lines of57Fe nuclei in RF magnetic field  

Science Journals Connector (OSTI)

It is shown experimentally, that for Moessbauer nuclei affected by the radio-frequency (RF) magnetic field of sufficient intensity at frequencies corresponding to ... occurs. Depending on the frequency of alterna...

F. G. Vagizov

1990-08-01T23:59:59.000Z

268

RF Analysis of ITER Remote Steering Antenna for Electron-Cyclotron Plasma Heating  

Science Journals Connector (OSTI)

An application of remote RF beam steering concept, based on image multiplication phenomena in a corrugated square waveguide, to electron-cyclotron plasma heating and current drive for ITER has been ... breakdown,...

G.G. Denisov; S.V. Kuzikov; N. Kobayashi

2001-12-01T23:59:59.000Z

269

Ignition of rf-Excited Lasers with Solid State and Tube Generators  

Science Journals Connector (OSTI)

An rf-excited CO2 laser has been developed at the Technical University Vienna. The construction bases upon a fast axial gas flow system with the gas flow divided into eight discharge tubes. The equivalent distrib...

B. Walter; M. Bohrer; D. Schuöcker

1990-01-01T23:59:59.000Z

270

E-Print Network 3.0 - atmospheric rf device Sample Search Results  

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

results for: atmospheric rf device Page: << < 1 2 3 4 5 > >> 1 Packaging of Ka-Band Patch Antenna and Optoelectronic Components for Dual-Mode Indoor Wireless Communication...

271

Ion energy cost in a combined inductive-capacitive rf discharge  

Science Journals Connector (OSTI)

Experimental measurements were made of the ion energy cost ? as a function of the parameters of a combined rf inductive-capacitive discharge at low pressures (p<10?2 Torr). It was established that ?...does not de...

S. V. Dudin; A. V. Zykov; K. I. Polozhii; V. I. Farenik

1998-11-01T23:59:59.000Z

272

Automatic Pole and Q-Value Extraction for RF Structures  

SciTech Connect (OSTI)

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.

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

2011-09-01T23:59:59.000Z

273

Wide-Range Bolometer with RF Readout TES  

E-Print Network [OSTI]

To improve both scalability and noise-filtering capability of a Transition-Edge Sensor (TES), a new concept of a thin-film detector is suggested, which is based on embedding a microbridge TES into a high-Q planar GHz range resonator weakly coupled to a 50 Ohm-readout transmission line. Such a TES element is designed as a hot-electron microbolometer coupled to a THz range antenna and as a load of the resonator at the same time. A weak THz signal coupled to the antenna heats the microbridge TES, thus reducing the quality factor of the resonator and leading to a power increment in the readout line. The power-to-power conversion gain, an essential figure of merit, is estimated to be above 10. To demonstrate the basic concept, we fabricated and tested a few submicron sized devices from Nb thin films for operation temperature about 5 K. The dc and rf characterization of the new device is made at a resonator frequency about 5.8 GHz. A low-noise HEMT amplifier is used in our TES experiments without the need for a SQU...

Shitov, S V; Kuzmin, A A; Merker, M; Arndt, M; Wuensch, S H; Ilin, K S; Erhan, E; Ustinov, A; Siegel, M

2014-01-01T23:59:59.000Z

274

Superconducting RF Linac Technology for ERL Light Sources  

SciTech Connect (OSTI)

Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity�������¢����������������s Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

Chris Tennant

2005-08-01T23:59:59.000Z

275

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-Print Network [OSTI]

LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV 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 2003 Major Subject: Physics LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to Texas A&M University in partial fulfillment of the requirements...

Ryjkov, Vladimir Leonidovich

2005-02-17T23:59:59.000Z

276

Comparison of the theory and the practice of rf current drive  

SciTech Connect (OSTI)

The theory of rf-driven plasma currents is applied to the lower-hybrid experiments on the PLT tokamak. Particular emphasis is placed on those experiments in which the plasma current was varying. The comparison between theory and experiment is made with respect to the efficiency with which rf energy was converted to poloidal magnetic field energy. Good agreement is found irrespective of whether the current was increasing, constant, or decreasing.

Karney, C.F.F.; Fisch, N.J.; Jobes, F.C.

1984-10-01T23:59:59.000Z

277

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

SciTech Connect (OSTI)

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.

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

278

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

SciTech Connect (OSTI)

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.

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

2011-06-01T23:59:59.000Z

279

Fractional and fractal derivatives modeling of turbulence  

E-Print Network [OSTI]

This study makes the first attempt to use the 2/3-order fractional Laplacian modeling of enhanced diffusing movements of random turbulent particle resulting from nonlinear inertial interactions. A combined effect of the inertial interactions and the molecule Brownian diffusivities is found to be the bi-fractal mechanism behind multifractal scaling in the inertial range of scales of moderate Reynolds number turbulence. Accordingly, a stochastic equation is proposed to describe turbulence intermittency. The 2/3-order fractional Laplacian representation is also used to construct a fractional Reynolds equation for nonlinear interactions of fluctuating velocity components, underlying turbulence spacetime fractal structures of Levy 2/3 stable distribution. The new perspective of this study is that the fractional calculus is an effective approach modeling of chaotic fractal phenomena induced by nonlinear interactions.

Wen Chen

2005-11-30T23:59:59.000Z

280

Bio-oil fractionation and condensation  

DOE Patents [OSTI]

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.

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

2013-07-02T23:59:59.000Z

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


281

Soil and litter respiration rates in different microhabitats of a mixed oak-conifer forest and their control by edaphic conditions and substrate quality  

Science Journals Connector (OSTI)

Soil and litter respiration rates were measured under canopies ofQuercus floribunda, Q. leucotrichophora, Cedrus deodara, Cupressus torulosa and mixed tree species by alkali absorption. The soil and litter sample...

C. K. Tewary; Uma Pandey; J. S. Singh

1982-01-01T23:59:59.000Z

282

Short-Term Effects of Experimental Burning and Thinning on Soil Respiration in an Old-Growth, Mixed-Conifer Forest  

Science Journals Connector (OSTI)

To understand the roles of forest management practices in meeting the goals of forest sustainability and CO2...sequestration, we evaluated the effects of burning and thinning treatments on soil respiration and so...

Siyan Ma; Jiquan Chen; Malcolm North; Heather E. Erickson…

2004-07-01T23:59:59.000Z

283

Development of plutonium aerosol fractionation system  

E-Print Network [OSTI]

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...

Mekala, Malla R.

1993-01-01T23:59:59.000Z

284

Effect of organic-vapor mixtures on the service life of respirator cartridges. Part 1  

SciTech Connect (OSTI)

We challenged pairs of MSA respirator cartridges with two compounds, isopropyl alcohol (IPA) and methyl ethyl ketone (MEK), to study the adsorption characteristics of organic vapors on cartridge performance. Each vapor was injected at three concentrations: (1) each at 10 times the respective Threshold Limit Value (TLV), (2) as a mixture at a concentration equal to the sum of the two single concentrations of item (1), and (3) each alone at a concentration equal to the total-mixture challenge concentration of item (2). The experiments were repeated at 20% and 85% relative humidities. One-percent and ten-percent breakthrough times were observed experimentally in every case, and breakthrough times of the mixture agreed with the single, high-concentration challenge. Experimental data were matched to a theoretical model derived from modified Wheeler-Robell equations and showed close correlations between adsorption-rate constants for the mixture and for the individual compounds. Based on these first experiments, we feel that an accurate mathematical model is possible, and further experiments are planned to verify this. 12 refs., 1 fig., 3 tabs.

Swearengen, P.M.; Weaver, S.C.

1985-01-01T23:59:59.000Z

285

Carbon Isotopic Studies of Assimilated and Ecosystem Respired CO2 in a Southeastern Pine Forest  

SciTech Connect (OSTI)

Carbon dioxide is the major “greenhouse” gas responsible for global warming. Southeastern pine forests appear to be among the largest terrestrial sinks of carbon dioxide in the US. This collaborative study specifically addressed the isotopic signatures of the large fluxes of carbon taken up by photosynthesis and given off by respiration in this ecosystem. By measuring these isotopic signatures at the ecosystem level, we have provided data that will help to more accurately quantify the magnitude of carbon fluxes on the regional scale and how these fluxes vary in response to climatic parameters such as rainfall and air temperature. The focus of the MBL subcontract was to evaluate how processes operating at the physiological and ecosystem scales affects the resultant isotopic signature of plant waxes that are emitted as aerosols into the convective boundary layer. These wax aerosols provide a large-spatial scale integrative signal of isotopic discrimination of atmospheric carbon dioxide by terrestrial photosynthesis (Conte and Weber 2002). The ecosystem studies have greatly expanded of knowledge of wax biosynthetic controls on their isootpic signature The wax aerosol data products produced under this grant are directly applicable as input for global carbon modeling studies that use variations in the concentration and carbon isotopic composition of atmospheric carbon dioxide to quantify the magnitude and spatial and temporal patterns of carbon uptake on the global scale.

Maureen H. Conte

2008-04-10T23:59:59.000Z

286

The evaluation of a valveless disposable respirator for use as respiratory protection against exposure to Halothane (2-Bromo-2-Chloro-1,1,1-Trifluoroethane)  

E-Print Network [OSTI]

and Health Administration (MSHA), and the V. S. Department of Health and Human Services' National Institute for Occupational Safety and Health (NIOSH). The 30CFR11 regulation does not address the testing of valveless organic vapor respirators. In 1975... no criteria by which a valveless organic vapor respirator can receive MSHA-NIOSH approval. The Bendix report , however, 3 produced very interesting performance data which is the basis of this thesis work. The concentra tion of challenge agent inside of a...

Gaudet, Glenn Lawrence

1980-01-01T23:59:59.000Z

287

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

SciTech Connect (OSTI)

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.

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

288

Comparison of Measured and Calculated Coupling between a Waveguide and an RF Cavity Using CST Microwave Studio  

SciTech Connect (OSTI)

Accurate predications of RF coupling between an RF cavity and ports attached to it have been an important study subject for years for RF coupler and higher order modes (HOM) damping design. We report recent progress and a method on the RF coupling simulations between waveguide ports and RF cavities using CST Microwave Studio in time domain (Transit Solver). Comparisons of the measured and calculated couplings are presented. The simulated couplings and frequencies agree within {approx} 10% and {approx} 0.1% with the measurements, respectively. We have simulated couplings with external Qs ranging from {approx} 100 to {approx} 100,000, and confirmed with measurements. The method should also work well for higher Qs, and can be easily applied in RF power coupler designs and HOM damping for normal-conducting and superconducting cavities.

J. Shi; H. Chen; S. Zheng; D. Li; R.A. Rimmer; H. Wang

2006-06-26T23:59:59.000Z

289

Application of new simulation algorithms for modeling rf diagnostics of electron clouds  

SciTech Connect (OSTI)

Traveling wave rf diagnostics of electron cloud build-up show promise as a non-destructive technique for measuring plasma density and the efficacy of mitigation techniques. However, it is very difficult to derive an absolute measure of plasma density from experimental measurements for a variety of technical reasons. Detailed numerical simulations are vital in order to understand experimental data, and have successfully modeled build-up. Such simulations are limited in their ability to reproduce experimental data due to the large separation of scales inherent to the problem. Namely, one must resolve both rf frequencies in the GHz range, as well as the plasma modulation frequency of tens of MHz, while running for very long simulations times, on the order of microseconds. The application of new numerical simulation techniques allow us to bridge the simulation scales in this problem and produce spectra that can be directly compared to experiments. The first method is to use a plasma dielectric model to measure plasma-induced phase shifts in the rf wave. The dielectric is modulated at a low frequency, simulating the effects of multiple bunch crossings. This allows simulations to be performed without kinetic particles representing the plasma, which both speeds up the simulations as well as reduces numerical noise from interpolation of particle charge and currents onto the computational grid. Secondly we utilize a port boundary condition model to simultaneously absorb rf at the simulation boundaries, and to launch the rf into the simulation. This method improves the accuracy of simulations by restricting rf frequencies better than adding an external (finite) current source to drive rf, and absorbing layers at the boundaries. We also explore the effects of non-uniform plasma densities on the simulated spectra.

Veitzer, Seth A.; Smithe, David N.; Stoltz, Peter H. [Tech-X Corporation, Boulder, CO, 80303 (United States)

2012-12-21T23:59:59.000Z

290

Impact of variable RBE on proton fractionation  

SciTech Connect (OSTI)

Purpose: To explore the impact of variable proton relative biological effectiveness (RBE) on dose fractionation for clinically relevant situations. A generic RBE = 1.1 is generally used for isoeffect calculations, while experimental studies showed that proton RBE varies with tissue type, dose, and linear energy transfer (LET). Methods: An analytical expression for the LET and {alpha}/{beta} dependence of the linear-quadratic (LQ) model has been used for proton simulations in parallel with the assumption of a generic RBE = 1.1. Calculations have been performed for ranges of LET values and fractionation sensitivities to describe clinically relevant cases, such as the treatment of head and neck and prostate tumors. Isoeffect calculations were compared with predictions from a generic RBE value and reported clinical results. Results: The generic RBE = 1.1 appears to be a reasonable estimate for the proton RBE of rapidly growing tissues irradiated with low LET radiation. However, the use of a variable RBE predicts larger differences for tissues with low {alpha}/{beta} (both tumor and normal) and at low doses per fraction. In some situations these differences may appear in contrast to the findings from photon studies highlighting the importance of accurate accounting for the radiobiological effectiveness of protons. Furthermore, the use of variable RBE leads to closer predictions to clinical results. Conclusions: The LET dependence of the RBE has a strong impact on the predicted effectiveness of fractionated proton radiotherapy. The magnitude of the effect is modulated by the fractionation sensitivity and the fractional dose indicating the need for accurate analyses both in the target and around it. Care should therefore be employed for changing clinical fractionation patterns or when analyzing results from clinical studies for this type of radiation.

Dasu, Alexandru; Toma-Dasu, Iuliana [Department of Radiation Physics UHL, County Council of Oestergoetland, 581 85 Linkoeping (Sweden) and Radiation Physics, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping University, 581 83 Linkoeping (Sweden); Medical Radiation Physics, Stockholm University and Karolinska Institute, 171 76 Stockholm (Sweden)

2013-01-15T23:59:59.000Z

291

Generic Wave-Function Description of Fractional Quantum Anomalous Hall States and Fractional Topological Insulators  

Science Journals Connector (OSTI)

We propose a systematical approach to construct generic fractional quantum anomalous Hall states, which are generalizations of the fractional quantum Hall states to lattice models with zero net magnetic field and full lattice translation symmetry. Local and translationally invariant Hamiltonians can also be constructed, for which the proposed states are unique ground states. Our result demonstrates that generic chiral topologically ordered states can be realized in lattice models, without requiring magnetic translation symmetry and Landau level structure. We further generalize our approach to fractional topological insulators, and provide the first explicit wave-function description of fractional topological insulators in the absence of spin conservation.

Xiao-Liang Qi

2011-09-15T23:59:59.000Z

292

On sampling fractions and electron shower shapes  

SciTech Connect (OSTI)

We study the usage of various definitions of sampling fractions in understanding electron shower shapes in a sampling multilayer electromagnetic calorimeter. We show that the sampling fractions obtained by the conventional definition (I) of (average observed energy in layer)/(average deposited energy in layer) will not give the best energy resolution for the calorimeter. The reason for this is shown to be the presence of layer by layer correlations in an electromagnetic shower. The best resolution is obtained by minimizing the deviation from the total input energy using a least squares algorithm. The 'sampling fractions' obtained by this method (II) are shown to give the best resolution for overall energy. We further show that the method (II) sampling fractions are obtained by summing the columns of a non-local {lambda} tensor that incorporates the correlations. We establish that the sampling fractions (II) cannot be used to predict the layer by layer energies and that one needs to employ the full {lambda} tensor for this purpose. This effect is again a result of the correlations.

Peryshkin, Alexander; Raja, Rajendran; /Fermilab

2011-12-01T23:59:59.000Z

293

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

SciTech Connect (OSTI)

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.

Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

2012-05-01T23:59:59.000Z

294

RF Heating and Current Drive in Magnetically Confined Plasma: a Historical Perspective  

SciTech Connect (OSTI)

The history of high power RF waves injected into magnetically confined plasma for the purposes of heating to fusion relevant temperatures spans nearly five decades. The road to success demanded the development of the theory of wave propagation in high temperature plasma in complex magnetic field geometries, development of antenna structures and transmission lines capable of handling high RF powers, and the development of high power RF (microwave) sources. In the early days, progress was hindered by the lack of good confinement of energetic particles formed by high power RF wave-plasma interactions. For example, in the ion cyclotron resonance frequency regime (ICRF) ions with energies in the multi-100keV, or even MeV range may be formed due to the presence of efficient 'minority species' absorption. Electrons with similar energies can be formed upon the injection of RF waves in the electron cyclotron resonance (ECRH) or lower hybrid range of frequencies (LHRF) because of quasi-linear Landau (cyclotron) interactions between waves and particles. In this paper a summary of four decades of historical evolution of wave heating and current drive results will be given.

Porkolab, Miklos [Massachusetts Institute of Technology, Plasma Science and Fusion Center and Department of Physics, NW 16-288, 167 Albany Street, Cambridge, MA 02139 (United States)

2007-09-28T23:59:59.000Z

295

Impaired mitochondrial respiration and protein nitration in the rat hippocampus after acute inhalation of combustion smoke  

SciTech Connect (OSTI)

Survivors of massive inhalation of combustion smoke endure critical injuries, including lasting neurological complications. We have previously reported that acute inhalation of combustion smoke disrupts the nitric oxide homeostasis in the rat brain. In this study, we extend our findings and report that a 30-minute exposure of awake rats to ambient wood combustion smoke induces protein nitration in the rat hippocampus and that mitochondrial proteins are a sensitive nitration target in this setting. Mitochondria are central to energy metabolism and cellular signaling and are critical to proper cell function. Here, analyses of the mitochondrial proteome showed elevated protein nitration in the course of a 24-hour recovery following exposure to smoke. Mass spectrometry identification of several significantly nitrated mitochondrial proteins revealed diverse functions and involvement in central aspects of mitochondrial physiology. The nitrated proteins include the ubiquitous mitochondrial creatine kinase, F1-ATP synthase {alpha} subunit, dihydrolipoamide dehydrogenase (E3), succinate dehydrogenase Fp subunit, and voltage-dependent anion channel (VDAC1) protein. Furthermore, acute exposure to combustion smoke significantly compromised the respiratory capacity of hippocampal mitochondria. Importantly, elevated protein nitration and reduced mitochondrial respiration in the hippocampus persisted beyond the time required for restoration of normal oxygen and carboxyhemoglobin blood levels after the cessation of exposure to smoke. Thus, the time frame for intensification of the various smoke-induced effects differs between blood and brain tissues. Taken together, our findings suggest that nitration of essential mitochondrial proteins may contribute to the reduction in mitochondrial respiratory capacity and underlie, in part, the brain pathophysiology after acute inhalation of combustion smoke.

Lee, Heung M.; Reed, Jason; Greeley, George H. [Department of Surgery, University of Texas Medical Branch (United States); Englander, Ella W. [Department of Surgery, University of Texas Medical Branch (United States); Shriners Hospitals for Children, Galveston, TX (United States)], E-mail: elenglan@utmb.edu

2009-03-01T23:59:59.000Z

296

Copper isotope fractionation in acid mine drainage. | EMSL  

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

Copper isotope fractionation in acid mine drainage. Copper isotope fractionation in acid mine drainage. Abstract: We surveyed the Cu isotopic composition of primary minerals and...

297

Carbon isotope fractionation in protoplanetary disks  

E-Print Network [OSTI]

We investigate the gas-phase and grain-surface chemistry in the inner 30 AU of a typical protoplanetary disk using a new model which calculates the gas temperature by solving the gas heating and cooling balance and which has an improved treatment of the UV radiation field. We discuss inner-disk chemistry in general, obtaining excellent agreement with recent observations which have probed the material in the inner regions of protoplanetary disks. We also apply our model to study the isotopic fractionation of carbon. Results show that the fractionation ratio, 12C/13C, of the system varies with radius and height in the disk. Different behaviour is seen in the fractionation of different species. We compare our results with 12C/13C ratios in the Solar System comets, and find a stark contrast, indicative of reprocessing.

Paul M. Woods; Karen Willacy

2008-12-01T23:59:59.000Z

298

Composting of the solid fraction of digestate derived from pig slurry: Biological processes and compost properties  

Science Journals Connector (OSTI)

Abstract The aim of this paper was to assess the characteristics of the solid fractions (SF) obtained by mechanical separation of digestate, their compostability and compost quality. To do so, the SF of digestates obtained from anaerobic digestion of pig slurry, energy crops and agro-industrial residues were sampled in five plants located in Northern Italy. Results obtained indicated that anaerobic digestion by itself promoted the high biological stability of biomasses with a Potential Dynamic Respiration Index (PDRI) close to 1000 mgO2 kg V S?1 h?1. Subsequent composting of digestates, with an added bulking agent, did not give remarkably different results, and led only to a slight modification of the characteristics of the initial non-composted mixtures; the composts obtained fully respected the legal limits for high quality compost. Chemical studies of organic matter composition of the biomasses by using CP MAS 13C NMR, indicated that the compost was composed of a high relative content of O-alkyl-C (71.47% of total C) (cellulose and hemicelluloses) and a low alkyl-C (12.42%) (i.e. volatile fatty acids, steroid-like molecules, aliphatic biopolymers and proteins).

Fulvia Tambone; Laura Terruzzi; Barbara Scaglia; Fabrizio Adani

2014-01-01T23:59:59.000Z

299

The Fractional Kinetic Equation and Thermonuclear Functions  

E-Print Network [OSTI]

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.

H. J. Haubold; A. M. Mathai

2000-01-16T23:59:59.000Z

300

Design Concepts for RF-DC Conversion in Particle Accelerator Systems  

E-Print Network [OSTI]

In many particle accelerators considerable amounts of RF power reaching the megawatt level are converted into heat in dummy loads. After an overview of RF power in the range 200 MHz to 1 GHz dissipated at CERN we discuss several developments that have come up in the past using vacuum tube technology for RF-DC conversion. Amongst those the developments of the cyclotron wave converter CWC appears most suitable. With the availability of powerful Schottky diodes the solid state converter aspect has to be addressed as well. One of the biggest problems of Schottky diode based structures is the junction capacity. GaAs and GaN Schottky diodes show a significant reduction of this junction capacity as compared to silicon. Small rectenna type converter units which have been already developed for microwave powered helicopters can be used in waveguides or with coaxial power dividers.

Caspers, F; Grudiev, A; Sapotta, H

2010-01-01T23:59:59.000Z

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


301

Cryogenic test of a proof-of-principle superconducting rf-dipole deflecting and crabbing cavity  

Science Journals Connector (OSTI)

Recent applications in need of compact low-frequency deflecting and crabbing cavities have initiated the design and development of new superconducting structures operating at high gradients with low losses. Previously, TM110-type deflecting and crabbing cavities were developed and have also been operated successfully. However, these geometries are not favorable designs for low operating frequencies. The superconducting rf-dipole cavity is the first compact deflecting and crabbing geometry that has demonstrated high gradients and high shunt impedance. Since the fundamental operating mode is the lowest mode and is widely separated from the nearest higher order mode, the rf-dipole design is an attractive geometry for effective damping of the higher order modes in high current applications. A 400 MHz rf-dipole cavity was designed, fabricated, and tested as a proof-of-principle cavity. The cavity achieved high operating gradients, and the multipacting levels were easily processed and did not reoccur.

S. U. De Silva and J. R. Delayen

2013-08-16T23:59:59.000Z

302

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

SciTech Connect (OSTI)

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.

McGuire, Gary; Martin, Allen; Noonan, John

2010-10-30T23:59:59.000Z

303

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

DOE Patents [OSTI]

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.

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

2007-08-14T23:59:59.000Z

304

Alternate airborne release fraction determination for hazardous waste management storage repository hazard categorization at the Lawrence Livermore National Laboratory  

SciTech Connect (OSTI)

Hazardous Waste Management (HWM) facilities are used in the handling and processing of solid and liquid radioactive, hazardous, mixed, and medical wastes generated at Lawrence Livermore National Laboratory (LLNL). Waste may be treated or stored in one of the HWM facility units prior to shipment off site for treatment or disposal. Planned facilities such as the Decontamination and Waste Treatment Facility (DWTF) and the Building 280 Container Storage Unit are expected to handle similar waste streams. A hazard classification was preformed in each facility safety analysis report (SAR) according to the DOE Standard 1027-92 `Hazard Categorization and Accident Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports.` The general methodology practiced by HWM to determine alternate airborne release fractions (ARFs) in those SARs was based upon a beyond evaluation basis earthquake accident scenario characterized by the release of the largest amount of respirable, airborne radioactive material. The alternate ARF was calculated using a three-factor formula consisting of the fraction of failed waste containers, fraction of material released from failed waste containers,and the fraction of material entrained to the environment. Recently, in deliberation with DOE-Oakland representatives, HWM decided to modify this methodology. In place of the current detailed analysis, a more straightforward process was proposed based upon material form, credible accident environments, and empirical data. This paper will discuss the methodology and derivation of ARFs specific to HWM treatment and storage facilities that are alternative to those presented in DOE-STD-1027-92.

Brumburgh, G.P.

1998-05-01T23:59:59.000Z

305

Parameters affecting the stability of the digestate from a two-stage anaerobic process treating the organic fraction of municipal solid waste  

SciTech Connect (OSTI)

This paper focused on the factors affecting the respiration rate of the digestate taken from a continuous anaerobic two-stage process treating the organic fraction of municipal solid waste (OFMSW). The process involved a hydrolytic reactor (HR) that produced a leachate fed to a submerged anaerobic membrane bioreactor (SAMBR). It was found that a volatile solids (VS) removal in the range 40-75% and an operating temperature in the HR between 21 and 35 {sup o}C resulted in digestates with similar respiration rates, with all digestates requiring 17 days of aeration before satisfying the British Standard Institution stability threshold of 16 mg CO{sub 2} g VS{sup -1} day{sup -1}. Sanitization of the digestate at 65 {sup o}C for 7 days allowed a mature digestate to be obtained. At 4 g VS L{sup -1} d{sup -1} and Solid Retention Times (SRT) greater than 70 days, all the digestates emitted CO{sub 2} at a rate lower than 25 mg CO{sub 2} g VS{sup -1} d{sup -1} after 3 days of aeration, while at SRT lower than 20 days all the digestates displayed a respiration rate greater than 25 mg CO{sub 2} g VS{sup -1} d{sup -1}. The compliance criteria for Class I digestate set by the European Commission (EC) and British Standard Institution (BSI) could not be met because of nickel and chromium contamination, which was probably due to attrition of the stainless steel stirrer in the HR.

Trzcinski, Antoine P., E-mail: a.trzcinski05@ic.ac.uk [Department of Chemical Engineering, Imperial College of Science and Technology and Medicine, Prince Consort Road, London SW7 2AZ (United Kingdom); Stuckey, David C., E-mail: d.stuckey@ic.ac.uk [Department of Chemical Engineering, Imperial College of Science and Technology and Medicine, Prince Consort Road, London SW7 2AZ (United Kingdom)

2011-07-15T23:59:59.000Z

306

Titanium nitride thin films deposited by reactive pulsed-laser ablation in RF plasma  

Science Journals Connector (OSTI)

Titanium nitride thin films were deposited on Si (100) substrates by pulsed laser ablation of a titanium target in a N2 atmosphere (gas pressure approx. 10 Pa) using a doubled frequency Nd:YAG laser (532 nm) also assisted by a 13.56-MHz radio frequency (RF) plasma. Deposition was carried out at various substrate temperatures ranging from 373 up to 873 K and films were analyzed by X-ray diffractometry, scanning electron microscopy and optical emission spectroscopy. A comparison between the ‘normal’ pulsed laser deposition (PLD) and the RF plasma-assisted PLD showed the influence of the plasma on the structural characteristics of the thin films.

A. Giardini; V. Marotta; S. Orlando; G.P. Parisi

2002-01-01T23:59:59.000Z

307

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

DOE Patents [OSTI]

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.

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

1985-01-01T23:59:59.000Z

308

Fractionalized exergy for evaluating research performance  

Science Journals Connector (OSTI)

The approach based on “thermodynamic” considerations that can quantify research performance using an exergy term defined as X = iC, where i is the impact and C is the number of citations is now extended to cases where fractionalized counting ... Keywords: author productivity, citation analysis, impact factor, scientometrics

Gangan Prathap

2011-11-01T23:59:59.000Z

309

Fractional Quantum Hall Effect and Nonabelian Statistics  

Science Journals Connector (OSTI)

......Articles Fractional Quantum Hall Effect and Nonabelian Statistics N...rc=1/8-1/8=0; this effect would be due to the Pfaffian...Sloan Foundation Fellow- ship and by NSF PYI DMR-9157484...ed.), The Quantum Hall Effect, 2nd edition (Springer, New......

N. Read; G. Moore

1992-01-01T23:59:59.000Z

310

Measurement of the D -> pipi branching fractions  

E-Print Network [OSTI]

Using data from CLEO II at the Cornell Electron Storage Ring we provide a new measurement of the branching fraction for D0 --> pi+pi-, and we present the first measurements of D0 --> pi0pi0 and of D+ --> pi+pi0, which is ...

Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.

1993-09-01T23:59:59.000Z

311

Measurement of the D*(2010) branching fractions  

E-Print Network [OSTI]

We report a measurement of the D*+ and D*0 decay branching fractions based on 780 pb-1 of data collected with the CLEO II detector. For radiative D*+ decay, we obtain an upper limit, B(D*+ --> D+ gamma) < 4.2% (90% confidence ...

Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.

1992-10-01T23:59:59.000Z

312

Fractional Quantization of the Hall Effect  

DOE R&D Accomplishments [OSTI]

The Fractional Quantum Hall Effect is caused by the condensation of a two-dimensional electron gas in a strong magnetic field into a new type of macroscopic ground state, the elementary excitations of which are fermions of charge 1/m, where m is an odd integer. A mathematical description is presented.

Laughlin, R. B.

1984-02-27T23:59:59.000Z

313

Real-time imaging of the spatial distribution of rf-heating in NMR samples during broadband decoupling  

E-Print Network [OSTI]

by the temperature control system. Moreover, as the heating is spatially inhomogeneous, higher temperature increases of the numerical simulations. Since electric fields manifest themselves by rf-heating, the E-field distributionReal-time imaging of the spatial distribution of rf-heating in NMR samples during broadband

Wider, Gerhard

314

APS DPP Meeting, Quebec City Canada R V Budny 2327 October 2000 Comparison of RF-heated with  

E-Print Network [OSTI]

42 nd APS DPP Meeting, Quebec City Canada R V Budny 23­27 October 2000 JG00.293/1 Comparison of RF 2000 JG00.293/3 Conclusions Motivation ICRH ­ heated ELMy plasmas are suggested for reactor startup heated ELMy plasmas Heating power lower than desired (close to L-mode) VTor for RF in Co-Ip direction

Budny, Robert

315

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

E-Print Network [OSTI]

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

Boyer, Edmond

316

SPECIFICATION FOR A RF SHIELDED ENCLOSURE 1. Scope -This specification covers the general requirements for the design, construction,  

E-Print Network [OSTI]

the following: a. Architecturally styled RF doors and windows. b. RF attenuating filters for power, telephone. Honeycomb grills for HVAC vents and floor drains. g. Conductive metallized fabric or copper foil on walls, and filter insertion loss should be tailored to meet the actual needs of the owner. Furthermore

Groppi, Christopher

317

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

DOE Patents [OSTI]

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.

Norem, James H.; Pellin, Michael J.

2013-06-11T23:59:59.000Z

318

Combined Delta-Nabla Sum Operator in Discrete Fractional Calculus  

E-Print Network [OSTI]

We introduce a more general discrete fractional operator, given by convex linear combination of the delta and nabla fractional sums. Fundamental properties of the new fractional operator are proved. As particular cases, results on delta and nabla discrete fractional calculus are obtained.

Bastos, Nuno R O

2010-01-01T23:59:59.000Z

319

Production of 1-m size uniform plasma by modified magnetron-typed RF discharge with a subsidiary electrode for resonance  

Science Journals Connector (OSTI)

A large-diameter uniform plasma of 1 m in size is produced using a modified magnetron-typed (MMT) RF plasma source at the frequency of 13.56 MHz. The construction and operation of the MMT RF plasma source are very simple and we can place two substrates simultaneously. To achieve an efficient production of high density plasma, a parallel resonance circuit is connected to one of the substrates which acts as a subsidiary RF electrode controlling the plasma parameters. In the case of the resonance the plasma density increases to approximately three times as much as that in case of non-resonance. The plasma density reaches?1×1011/cm3 in Ar at 1 mtorr when the RF input power is 2.8 kW. The MMT RF plasma source provides a plasma with uniformity within several percent over 1 m in diameter in front of the substrate in the low gas pressure regime.

Yuji Urano; Yunlong Li; Keiichi Kanno; Satoru Iizuka; Noriyoshi Sato

1998-01-01T23:59:59.000Z

320

Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents [OSTI]

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.

Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

1984-01-01T23:59:59.000Z

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


321

Particle-In-Cell/Monte Carlo Simulation of Ion Back BomBardment in a High Average Current RF Photo-Gun  

E-Print Network [OSTI]

High Average Current RF Photo-Gun J. Qiang Lawrence Berkeleyradio-frequency (RF) photo-gun using a particle-in-cell/ion motion inside the gun so that the ion power deposition

Qiang, J.

2010-01-01T23:59:59.000Z

322

Simulation and characterization of Cylindrical RF cavity with output section coupling for 250 kW CW C-band klystron  

Science Journals Connector (OSTI)

The klystron is a microwave tube capable to produce very high power that find wide use in communication, radar, material processing, particle accelerators and thermonuclear fusion reactors. The RF section has an important role in deciding the RF performance ...

O. S. Lamba; Meenu Kaushik; L. M. Joshi; Rakesh Meena; Debasish Pal; Vishnu Jindal; Priyanka Jangir; Vijay Singh; Sunit Kumar; Depender Kant

2011-02-01T23:59:59.000Z

323

Frequency-feedback tuning for single-cell cavity under rf heating  

SciTech Connect (OSTI)

A tuning system is described that is being used to match the source frequency of a high-power klystron on the resonant frequency of the prototype single-cell cavity for the 7-GeV Advance Photon Source (APS) storage ring. Typically a water-cooled piston tuner is required to adjust the reactive component of the cavity`s impedance to minimize reflected power back to the RF drive source. As the cavity watts expand due to RF heating, the resonant frequency decreases. Adjusting the source frequency to follow the cavity resonant frequency is a convenient method used to condition the cavity (for vacuum) at high power levels, in this case, 1 MV gap voltage at 100 kW power level. The tuning system consists of two coupling ports, a phase detector, a digitizing I/O system, and a DC coupled FM-modulated RF source. Proportional Integral Derivative (PID) loop parameters for the Experimental Physics and Industrial Control System (EPICS) software are calculated, and data is presented showing the damped response to peturbations on the loop. The timing system presented here does not need water-cooling, has no moving parts to wear out, and has an inherently faster response time. Its one limitation is the digitizing sampling rate. The only limitation in tuning range is the bandwidth of the RF source.

Stepp, J.D.; Bridges, J.F.

1993-08-01T23:59:59.000Z

324

Aluminum nitride for heatspreading in RF IC's L. La Spina a,*, E. Iborra b  

E-Print Network [OSTI]

phenomena Heatspreader Piezoelectric characteristics RF integration Thermal instabilities Thermal resistance that display a reduc- tion of more than 70% in the value of the thermal resistance. Ă? 2008 Elsevier Ltd. All lead to a very high thermal resistance. This has been demonstrated in our in-house silicon-on- glass

Technische Universiteit Delft

325

Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap  

E-Print Network [OSTI]

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...

Zhu, Feng

2012-02-14T23:59:59.000Z

326

Synthesis and Diagnosis of RF Filters in Liquid Crystalline Polymer (LCP) Substrate  

E-Print Network [OSTI]

Synthesis and Diagnosis of RF Filters in Liquid Crystalline Polymer (LCP) Substrate Souvik-consuming step in the manufacturing cycle. This paper presents the application of layout-level synthesis synthesized and fabricated. The results of synthesis are within 5% of EM measurement data. The fabricated

Swaminathan, Madhavan

327

Heterogeneous PLC-RF networking for LLNs Cdric Chauvenet*,** --Bernard Tourancheau*  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

328

Experimental Studies of RF Interference and Upset in Devices and Gates  

E-Print Network [OSTI]

Xingzhi Wen #12;Goals · Start with the study of the effects on the fundamental units of IC circuits, ie and protecting elements. · Develop on-chip sensing, registration, and protection circuitry. #12;Effects. · Effective protection and RF hardened design will be developed #12;RFI Effect on Diode I-V Characteristics

Anlage, Steven

329

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara  

E-Print Network [OSTI]

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara efficient way for a team of UAVs with Received Signal Strength Indicator (RSSI) sen- sors to locate radio locations requires integrating multiple signals from different UAVs into a Bayesian filter, hence requir

Scerri, Paul

330

Influence of Intense Beam in High Pressure Hydrogen Gas Filled RF Cavities  

SciTech Connect (OSTI)

The influence of an intense beam in a high-pressure gas filled RF cavity has been measured by using a 400 MeV proton beam in the Mucool Test Area at Fermilab. The ionization process generates dense plasma in the cavity and the resultant power loss to the plasma is determined by measuring the cavity voltage on a sampling oscilloscope. The energy loss has been observed with various peak RF field gradients (E), gas pressures (p), and beam intensities in nitrogen and hydrogen gases. Observed RF energy dissipation in single electron (dw) in N{sub 2} and H{sub 2} gases was 2 10{sup -17} and 3 10{sup -17} Joules/RF cycle at E/p = 8 V/cm/Torr, respectively. More detailed dw measurement have been done in H{sub 2} gas at three different gas pressures. There is a clear discrepancy between the observed dw and analytical one. The discrepancy may be due to the gas density effect that has already been observed in various experiments.

Yonehara, K.; Chung, M.; Collura, M.G.; Jana, M.R.; Leonova, M.; Moretti, A.; Popovic, M.; Schwarz, T.; Tollestrup, A.; /Fermilab; Johnson, R.P.; Franagan, G.; /Muons, Inc. /IIT

2012-05-01T23:59:59.000Z

331

Detachment-induced electron production in the early afterglow of pulsed cc-rf oxygen plasmas  

SciTech Connect (OSTI)

Line integrated electron densities are measured by 160.28 GHz Gaussian beam microwave interferometry in a 10 Hz pulsed (50% duty cycle) cc-rf oxygen discharge, operating at 13.56 MHz. Depending on the processing parameters, the oxygen rf discharge displays two different operation modes regarding its electronegativity. For higher rf power with negative self-bias voltage above -220 V, the oxygen discharge acts as electropositive plasma (n{sub -}/n{sub e} Much-Less-Than 1), whereas at lower rf power and self-bias voltage the plasma becomes strongly electronegative (n{sub -}/n{sub e}>2). In the latter mode, a significant electron density increase is measured in the early afterglow (<100 {mu}s) within a pressure range from 20 to 100 Pa. By use of a simple rate equation model, the temporal behavior of the electron density could be reproduced for both modes of electronegativity. The electron production in the early afterglow is mainly caused due to the detachment of negative atomic oxygen ions by metastable oxygen molecules.

Kuellig, C.; Dittmann, K.; Meichsner, J. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

2012-07-15T23:59:59.000Z

332

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron  

E-Print Network [OSTI]

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron Abstract-- Barium strontium titanate is a solid solution perovskite with a field-dependent permittivity.7 MV/cm. I. INTRODUCTION In recent years there has been much interest in thin-film barium strontium

York, Robert A.

333

High Power RF Tests on WR650 Pre-Stressed Planar Windows  

SciTech Connect (OSTI)

A new planar, ceramic window intended to be used with WR650 waveguide fundamental power couplers at 1300 MHz or 1500 MHz has been developed. It is based on the pre-stressed planar window concept tested in PEP II and LEDA. A test stand that made use of the 100kW CW 1500 MHz RF system in the JLAB FEL was commissioned and used to apply up to 80 kW traveling wave (TW)to the windows. Two different types of RF windows (brazed and diffusion bonded ceramics) with design specification of 50 kW CW in TW mode were successfully tested both as a gas barrier (intended to operate up to 2 psi) and as a vacuum barrier. The vacuum windows were able to maintain UHV quality vacuum and were successfully operated in the 10{sup -9} mbar range. An overview of the pre-stressed power windows, RF test stand, procedures and RF power testing results will be presented.

Stirbet, Mircea [JLAB; Davis, G. Kirk [JLAB; Elliott, Thomas S. [JLAB; King, Larry [JLAB; Powers, Thomas J. [JLAB; Rimmer, Robert A. [JLAB; Walker, Richard L. [JLAB

2009-11-01T23:59:59.000Z

334

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network [OSTI]

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell hal-00749873,version1-25Nov shortage until 2010. Research on epitaxial growth for thin film crystalline silicon solar cells has gained

335

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network [OSTI]

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell #12;2 1. Introduction: martin.labrune@polytechnique.edu ABSTRACT We report on heterojunction solar cells whose thin intrinsic

336

International Conference on Microwave and RF Heating MODELING OF A CYLINDRICAL APPLICATOR WITH THE  

E-Print Network [OSTI]

by comprehensive modeling specifying appropriate parameters of the excitation system and monitoring the electric10th International Conference on Microwave and RF Heating and experimentally. It appears that because of the uniform electric field distribution along the axis of the cylinder

Yakovlev, Vadim

337

CMOS RF down-conversion mixer design for low-power wireless communications  

E-Print Network [OSTI]

and the digital building blocks on a single chip. Indeed, both the full integration and the low-voltage design, 1 building blocks This paper aims to study the design of an integrated single-balanced mixer in CMOS 0.18 !m for the design of RF integrated circuits. Indeed, in recent years the huge efforts, provided

Paris-Sud XI, Université de

338

Development of fundamental power coupler for high-current superconducting RF cavity  

SciTech Connect (OSTI)

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.

Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

2012-05-20T23:59:59.000Z

339

Analytical model for ion angular distribution functions at rf biased surfaces with collisionless plasma sheaths  

E-Print Network [OSTI]

Analytical model for ion angular distribution functions at rf biased surfaces with collisionless plasma sheaths Laxminarayan L. Rajaa) Department of Aerospace Engineering and Engineering Mechanics The article presents an analytical model for evaluation of ion angular distribution functions IADFs at a radio

Raja, Laxminarayan L.

340

ION HEATING WITH RF FIELDS NEAR THE ION CYCLOTRON FREQUENCY J. D. Barter, J. C. Sprott  

E-Print Network [OSTI]

ION HEATING WITH RF FIELDS NEAR THE ION CYCLOTRON FREQUENCY by J. D. Barter, J. C. Sprott November. Our experiments of the past year, however, indicate that ion cyclotron resonance heating transmitted without consent of the author and major professor. #12;For several years we have been heating ions

Sprott, Julien Clinton

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


341

A 900MHz RF Energy Harvesting Module TARIS Thierry, VIGNERAS Valrie  

E-Print Network [OSTI]

harvesting. Different types of source are considered among them are: wind, solar, vibration, temperature and everywhere". It is a decisive asset to address power saving and energy management challenges in WSN with the state of art. II. BUILDING BLOCK DESIGN AND CHARACTERISTICS Figure 1. Building blocks of the RF

Paris-Sud XI, Université de

342

The Effect of rf-Irradiation on Electrochemical Deposition and Its Stabilization by Nanoparticle Doping  

E-Print Network [OSTI]

studied microscale singular perturbation mechanisms in the deposit surface tension and attachment kineticsThe Effect of rf-Irradiation on Electrochemical Deposition and Its Stabilization by Nanoparticle resulted from singular effects of gas-filled submicrometer bubbles or nanobubbles, which are generated

Jacob, Eshel Ben

343

The effect of rf-irradiation on electrochemical deposition and its stabilization by nanoparticle doping  

E-Print Network [OSTI]

(surface tension and attachment kinetics). We also studied electrochemical deposition in Zinc sulphateThe effect of rf-irradiation on electrochemical deposition and its stabilization by nanoparticle that these changes of patterning on all scales resulted from singular effects of gas-filled submicron bubbles

Jacob, Eshel Ben

344

RF Plasma Cathode-Neutralizer for Space Applications IEPC-2007-266  

E-Print Network [OSTI]

Raitses and Nathaniel J. Fisch Princeton Plasma Physics Laboratory, Princeton, NJ 08543, USA AbstractRF Plasma Cathode-Neutralizer for Space Applications IEPC-2007-266 Presented at the 30th: A new plasma cathode-neutralizer based on electron extraction from inductively coupled plasma (ICP

345

Low ion energy RF reactor using an array of plasmas through a grounded grid  

SciTech Connect (OSTI)

A reactor using localized remote plasma in a grid electrode is presented in this study. The aim is to reduce the ion bombardment energy inherent in RF capacitively coupled parallel plate reactors used to deposit large area thin film silicon solar cells. High ion bombardment energy could cause defects in silicon layers and deteriorate electrical interfaces, therefore, by reducing the ion bombardment energy, lower defect density might be obtained. In this study, the low ion bombardment energy results from the reactor design. By inserting a grounded grid close to the RF electrode of a parallel plate reactor, the electrode area asymmetry is increased while retaining the lateral uniformity required for large area deposition. This asymmetry causes a strong negative self-bias voltage, which reduces the time-averaged plasma potential and thus lowers the ion bombardment energy. In addition to the self-bias, the time evolution of plasma light emission and plasma potential RF waveform are also affected by the grid, thereby further reducing the time-averaged plasma potential and ion bombardment energy. Finally, a good correlation between the measured time-averaged plasma potential and measured low ion bombardment energy is found in a broad range of RF voltages.

Chesaux, Michaeel; Howling, Alan A.; Hollenstein, Christoph [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Domine, Didier; Kroll, Ulrich [Oerlikon Solar-Lab SA, rue du Puits-Godet 12a, CH-2000 Neuchatel (Switzerland)

2013-03-15T23:59:59.000Z

346

Low-frequency RF Coupling To Unconventional (Fat Unbalanced) Dipoles  

SciTech Connect (OSTI)

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

Ong, M M; Brown, C G; Perkins, M P; Speer, R D; Javedani, J B

2010-12-07T23:59:59.000Z

347

Clean Fractionation: Technology Available for Licensing  

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

Clean Fractionation Clean Fractionation National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov NREL is a national laboratory of the U.S. Department of Energy Offi ce of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. NREL/FS-7A1-43959 * October 2008 Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 10% postconsumer waste. You'll find more technologies available for licensing on the NREL Technology Transfer Web site at www.nrel.gov/technologytransfer/. National Renewable Energy Laboratory Innovation for Our Energy Future Biorefinery production costs are driven Insolubles Wash Cellulose pulp Lignocellulosic feedstock Solubles

348

Fluid catalytic cracking of heavy petroleum fractions  

SciTech Connect (OSTI)

A process is claimed for fluid catalytic cracking of residuum and other heavy oils comprising of gas oil, petroleum residue, reduced and whole crudes and shale oil to produce gasoline and other liquid products which are separated in various streams in a fractionator and associated vapor recovery equipment. The heat from combustion of coke on the coked catalyst is removed by reacting sulfur-containing coke deposits with steam and oxygen in a separate stripper-gasifier to produce a low btu gas stream comprising of sulfur compounds, methane, carbon monoxide, hydrogen, and carbon dioxide at a temperature of from about 1100/sup 0/F. To about 2200/sup 0/F. The partially regenerated catalyst then undergoes complete carbon removal in a regeneration vessel. The regenerated catalyst is recycled for re-use in the cracking of heavy petroleum fractions. The liquid products are gasoline, distillates, heavy fuel oil, and light hydrocarbons.

McHenry, K.W.

1981-06-30T23:59:59.000Z

349

Fractionation of five technical lignins by selective extraction in green solvents and characterisation of isolated fractions  

Science Journals Connector (OSTI)

Abstract Lignins from softwood, hardwood, grass and wheat straw were fractionated by selective extraction at ambient temperature using green solvents like acetone/water solutions of 10, 30, 50, 70 and 90% (v/v) acetone and ethyl acetate. A comparison between the isolated fractions and unfractionated lignins was made in terms of extraction yield, lignin solubility factor, molecular weight distribution and functional group composition. Low molecular weight (LMW) lignin fractions with narrow dispersity are obtained by extraction with ethyl acetate and acetone–water solution containing 30% acetone, with yields depending on the type and the functional group content of lignins. A significant amount (56%) of the organosolv hardwood lignin with low molecular weight (Mw = 1868 g/mol) and low dispersity was isolated from ethyl acetate. Insoluble fractions with very high molecular weight (Mw between 10 and 17 kg/mol) are obtained in low yield from acetone–water solutions with 50, 70 and 90% acetone. LMW lignins are in general less condensed and have lower aliphatic hydroxyl content than parent lignins while the HMW fractions have a higher content of condensed hydroxyls. Principal component analysis on the chemical composition of lignins and isolated fractions determined from 31P NMR data showed the high heterogeneity of the technical lignins. Partial least squares models based on FT-IR spectral data were developed to predict the functional group content determined by quantitative 31P NMR analysis of technical lignins and lignin fractions. This approach can be used to develop simple, rapid and accurate analytical tools to monitor and control the selective fractionation of lignin.

Carmen G. Boeriu; Firu?a I. Fi?ig?u; Richard J.A. Gosselink; August E. Frissen; Jan Stoutjesdijk; Francisc Peter

2014-01-01T23:59:59.000Z

350

Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I. Gonin2, S. Schreiber1  

E-Print Network [OSTI]

Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I Fermilab has developed and delivered to DESY Hamburg two RF guns for the operation of the phase I of the TESLA Test Facility (TTF) accelerator. The first RF gun (designated G3 in the following) has been

351

Design ad Modeling of a 17 GHz Photcxxthode RF Gun C. L. Lin, S. C. Chen, J. S. U'urtele, H. Temkin, 13. Danly *  

E-Print Network [OSTI]

Design ad Modeling of a 17 GHz Photcxxthode RF Gun C. L. Lin, S. C. Chen, J. S. U'urtele, H. Temkin of a high-frequencv(l7GHz), high accel- erating gradirnt(250hlv/rrl) photocathode RF gun is stud- ied in conventional DC guns followed by RF bunchers have reached their intrin- sic limitations and do not meet

Wurtele, Jonathan

352

Fractional Quantum Hall States in Graphene  

E-Print Network [OSTI]

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 \

Ahmed Jellal; Bellati Malika

2008-05-15T23:59:59.000Z

353

Pyrolysis of shale oil residual fractions  

SciTech Connect (OSTI)

The freezing point of JP-5, the Navy jet fuel, has been related to the n-alkane content, specifically n-hexadecane. In general, jet fuels from shale oil have the highest n-alkanes. The formation of n-alkanes in the jet fuel distillation range can be explained if large n-alkanes are present in the crude oil source. Quantities of large n-alkanes are insufficient, however, to explain the amounts found - up to 37% n-alkanes in the jet fuel range. Other possible precursors to small straight chain molecules are substituted cyclic compounds. Attack in the side chain obviously afford a path to an n-alkane. Aromatic hydrocarbons, esters, acids, amines, and ethers also have the potential to form n-alkanes if an unbranched alkyl chain is present in the molecule. Investigations showed that the best yield of the JP-5 cut comes at different times for the various fractions, but a time in the 60 to 120 min range would appear to be the optimum time for good yield at 450/sup 0/C. The longer time would be preferred with respect to lower potential n-alkane yield. None of the fractions gave n-alkane yields approaching the 37% amount found in the Shale-I JP-5. A temperature different than the 450/sup 0/C used here might affect the conversion percentage. Further the combined saturate, aromatic, and polar fractions may interact under pyrolysis conditions to give higher potential n-alkane yields than the fractions stressed independently.

Hazlett, R.N.; Beal, E.; Vetter, T.; Sonntag, R.; Moniz, W.

1980-01-01T23:59:59.000Z

354

Theoretical Predictions and Experimental Assessments of the Performance of Alumina RF Windows  

SciTech Connect (OSTI)

Radio frequency (RF) windows are the most likely place for catastrophic failure to occur in input power couplers for particle accelerators. Reliable RF windows are essential for the success of the Accelerator Production of Tritium (APT) program because there are over 1000 windows on the accelerator, and it takes more than one day to recover from a window failure. The goals of this research are to analytically predict the lifetime of the windows, to develop a conditioning procedure, and to evaluate the performance of the RF windows. The analytical goal is to predict the lifetime of the windows. The probability of failure is predicted by the combination of a finite element model of the window, Weibull probabilistic analysis, and fracture mechanics. The window assembly is modeled in a finite element electromagnetic code in order to calculate the electric fields in the window. The geometry (i.e. mesh) and electric fields are input into a translator program to generate the mesh and boundary conditions for a finite element thermal structural code. The temperatures and stresses are determined in the thermal/structural code. The geometry and thermal structural results are input into another translator program to generate an input file for the reliability code. Material, geometry and service data are also input into the reliability code. To obtain accurate Weibull and fatigue data for the analytical model, four point bend tests were done. The analytical model is validated by comparing the measurements to the calculations. The lifetime of the windows is then determined using the reliability code. The analytical model shows the window has a good thermal mechanical design and that fast fracture is unlikely to occur below a power level of 9 Mw. The experimental goal is to develop a conditioning procedure and evaluate the performance of RF windows. During the experimental evaluation, much was learned about processing of the windows to improve the RF performance. Methods of processing included grit blasting and using various coatings.

Karen Ann Cummings

1998-07-01T23:59:59.000Z

355

Fractionated Grid Therapy in Treating Cervical Cancers: Conventional Fractionation or Hypofractionation?  

SciTech Connect (OSTI)

Purpose: To evaluate the conventionally fractionated and hypofractionated grid therapy in debulking cervical cancers using the linear quadratic (LQ) model. Methods and Materials: A Monte Carlo technique was used to calculate the dose distribution of a commercially available grid in a 6-MV photon beam. The LQ model was used to evaluate the therapeutic outcome of both the conventionally fractionated (2 Gy/fraction) and hypofractionated (15 Gy/fraction) grid therapy regimens to debulk cervical cancers with different LQ parameters. The equivalent open-field dose (EOD) to the cancer cells and therapeutic ratio (TR) were defined by comparing grid therapy with the open debulking field. The clinical outcomes from 114 patients were used to verify our theoretical model. Results: The cervical cancer and normal tissue cell survival statistics for grid therapy in two regimens were calculated. The EODs and TRs were derived. The EOD was only a fraction of the prescribed dose. The TR was dependent on the prescribed dose and the LQ parameters of both the tumor and normal tissue cells. The grid therapy favors the acutely responding tumors inside radiosensitive normal tissues. Theoretical model predictions were consistent with the clinical outcomes. Conclusions: Grid therapy provided a pronounced therapeutic advantage in both the hypofractionated and conventionally fractionated regimens compared with that seen with single fraction, open debulking field regimens, but the true therapeutic advantage exists only in the hypofractionated grid therapy. The clinical outcomes and our study indicated that a course of open-field radiotherapy is necessary to control tumor growth fully after a grid therapy.

Zhang Hualin [Department of Radiation Medicine, Ohio State University, Columbus, OH (United States)], E-mail: zhang.568@osu.edu; Wang, Jian Z.; Mayr, Nina; Kong Xiang; Yuan Jiankui; Gupta, Nilendu; Lo, Simon; Grecula, John; Montebello, Joseph; Martin, Douglas [Department of Radiation Medicine, Ohio State University, Columbus, OH (United States); Yuh, William [Department of Radiology, Ohio State University, Columbus, OH (United States)

2008-01-01T23:59:59.000Z

356

Sliding force measurements on the LHC RF contact Plug In Modules at 15 K and in UHV  

E-Print Network [OSTI]

Some sliding RF contacts mounted in the Plug In Modules in the LHC interconnects failed during a thermal cycle between 4.2 K and room temperature. Gold-coated copperberyllium RF fingers buckled during the warm up of the machine, indicating that one or more parameters during operation (e.g. the friction coefficient under vacuum) could be different from what was used in the calculations. This report describes the measurement of the longitudinal forces acting on the sliding RF fingers at operating vacuum and temperatures.

Artoos, K; Renaglia, T

2008-01-01T23:59:59.000Z

357

Pyrolysis of shale oil vacuum distillate fractions  

SciTech Connect (OSTI)

The freezing point of US Navy jet fuel (JP-5) has been related to the amounts of large n-alkanes present in the fuel. This behavior applies to jet fuels derived from alternate fossil fuel resources, such as shale oil, coal, and tar sands, as well as those derived from petroleum. In general, jet fuels from shale oil have the highest and those from coal the lowest n-alkane content. The origin of these n-alkanes in the amounts observed, especially in shale-derived fuels, is not readily explained on the basis of literature information. Studies of the processes, particularly the ones involving thermal stress, used to produce these fuels are needed to define how the n-alkanes form from larger molecules. The information developed will significantly contribute to the selection of processes and refining techniques for future fuel production from shale oil. Carbon-13 nmr studies indicate that oil shale rock contains many long unbranched straight chain hydrocarbon groups. The shale oil derived from the rock also gives indication of considerable straight chain material with large peaks at 14, 23, 30, and 32 ppM in the C-13 nmr spectrum. Previous pyrolysis studies stressed fractions of shale crude oil residua, measured the yields of JP-5, and determined the content of potential n-alkanes in the JP-5 distillation range (4). In this work, a shale crude oil vacuum distillate (Paraho) was separated into three chemical fractions. The fractions were then subjected to nmr analysis to estimate the potential for n-alkane production and to pyrolysis studies to determine an experimental n-alkane yield.

Hazlett, R.N.; Beal, E.

1983-01-01T23:59:59.000Z

358

Pyrolysis of shale oil vacuum distillate fractions  

SciTech Connect (OSTI)

The freezing point of U.S. Navy jet fuel (JP-5) has been related to the amounts of large nalkanes present in the fuel. This behavior applies to jet fuels derived from alternate fossil fuel resources, such as shale oil, coal, and tar sands, as well as those derived from petroleum. In general, jet fuels from shale oil have the highest and those from coal the lowest n-alkane content. The origin of these n-alkanes in the amounts observed, especially in shale-derived fuels, is not readily explained on the basis of literature information. Studies of the processes, particularly the ones involving thermal stress, used to produce these fuels are needed to define how th n-alkanes form from larger molecules. The information developed will significantly contribute to the selection of processes and refining techniques for future fuel production from shale oil. Carbon-13 nmr studies indicate that oil shale rock contains many long unbranched straight chain hydrocarbon groups. The shale oil derived from the rock also gives indication of considerable straight chain material with large peaks at 14, 23, 30 and 32 ppm in the C-13 nmr spectrum. Previous pyrolysis studies stressed fractions of shale crude oil residua, measured the yields of JP-5, and determined the content of potential n-alkanes in the JP-5 distillation range (4). In this work, a shale crude oil vacuum distillate (Paraho) was separated into three chemical fractions. The fractions were then subjected to nmr analysis to estimate the potential for n-alkane production and to pyrolysis studies to determine an experimental n-alkane yield.

Hazlett, R.N.; Beal, E.

1983-02-01T23:59:59.000Z

359

Magnesium-Isotope Fractionation During Plant Growth  

Science Journals Connector (OSTI)

With three stable isotopes naturally abundant (24Mg, 78.992%; 25Mg, 10.003%; 26Mg, 11.005%), magnesium stable isotope fractionation may provide insights into these cycles. ... Measurements of the magnesium isotopic composition of chlorophylls, seeds, shoots, roots, leaves, exudates, and the limiting nutrient solution over time show that the plant appears to establish an isotopic equilibrium with the nutrient available to it and that the plant (in particular, the seeds and exudates) becomes enriched in the heavy isotopes of magnesium in a mass-dependent relationship as the plant reaches maturity. ...

Jay R. Black; Emanuel Epstein; William D. Rains; Qing-zhu Yin; William H. Casey

2008-10-01T23:59:59.000Z

360

Fractional electric charge and quark confinement  

E-Print Network [OSTI]

Owing to their fractional electric charges, quarks are blind to transformations that combine a color center phase with an appropriate electromagnetic one. Such transformations are part of a global $Z_6$-like center symmetry of the Standard Model that is lost when quantum chromodynamics (QCD) is treated as an isolated theory. This symmetry and the corresponding topological defects may be relevant to non-perturbative phenomena such as quark confinement, much like center symmetry and ordinary center vortices are in pure SU($N$) gauge theories. Here we report on our investigations of an analogous symmetry in a 2-color model with dynamical Wilson quarks carrying half-integer electric charge.

Sam R. Edwards; André Sternbeck; Lorenz von Smekal

2012-02-07T23:59:59.000Z

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361

Hydrolysis and fractionation of lignocellulosic biomass  

DOE Patents [OSTI]

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.

Torget, Robert W. (Littleton, CO); Padukone, Nandan (Denver, CO); Hatzis, Christos (Denver, CO); Wyman, Charles E. (Lakewood, CO)

2000-01-01T23:59:59.000Z

362

Polyfunctional catalyst for processiing benzene fractions  

SciTech Connect (OSTI)

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.

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

363

U-Th-Ra Fractionation During Weathering and River Transport  

Science Journals Connector (OSTI)

...aquatic environment of a phosphogypsum disposal area. J Environ...fractionation of the rare earth elements in a boreal...aquatic environment of a phosphogypsum disposal area. J Environ...fractionation of the rare earth elements in a boreal...

F. Chabaux; J. Riotte; O. Dequincey

364

Assessing the impacts of fractionation on pointing-intensive spacecraft  

E-Print Network [OSTI]

Fractionated spacecraft consist of physically independent, "free-flying" modules composed of various subsystems. Thus, a fractionated spacecraft might consist of one-module responsible for the power generation and storage, ...

O'Neill, Michael Gregory

2010-01-01T23:59:59.000Z

365

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

366

Fiber fractionation as a method of improving handsheet properties  

E-Print Network [OSTI]

to copyright. Vol. 78, No. 5 Tappi Journal 123 #12;Recycling used. Following fractionation, the tionation can

Abubakr, Said

367

Catalytic isomerization of the overhead fractions of straight run gasoline  

Science Journals Connector (OSTI)

The isomerization of the pentane and hexane fractions of gasoline on a platinum catalyst was studied, as...

N. R. Bursian; G. N. Maslyanskii…

1965-06-01T23:59:59.000Z

368

Cryogenic search for fractionally charged particles  

Science Journals Connector (OSTI)

An experiment was performed to test the hypothesis of cryogenic trapping of fractionally charged particles, suggested as a possible explanation for the results of LaRue, Fairbank, Hebard, and Phillips at Stanford. A Nb-filament source was built, which could be cooled to 4.2°K and rapidly heated to several hundred °K. The source was operated in the terminal of a 700-kV Cockcroft-Walton accelerator and energy spectra of positively charged particles emerging from the filament were measured under a variety of operating conditions. No events above a background of 10-2 counts/sec were found in the energy regions where one might have expected several hundred particles of charge +13e or +23e as the source was heated. A mass range from 10 MeV/c2 to 100 GeV/c2 was covered in the experiment. Although negative results are rarely unambiguous, our findings exclude one class of hypotheses which might have explained the apparent fractional charges of the Stanford experiments.

W. Kutschera; J. P. Schiffer; D. Frekers; W. Henning; M. Paul; K. W. Shepard; C. D. Curtis; C. W. Schmidt

1984-03-01T23:59:59.000Z

369

Process for stabilization of coal liquid fractions  

DOE Patents [OSTI]

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.

Davies, Geoffrey (Boston, MA); El-Toukhy, Ahmed (Alexandria, EG)

1987-01-01T23:59:59.000Z

370

Electron Spin Precession for the Time Fractional Pauli Equation  

E-Print Network [OSTI]

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.

Hosein Nasrolahpour

2011-04-05T23:59:59.000Z

371

Hamilton-Jacobi formulation of systems within Caputo's fractional derivative  

E-Print Network [OSTI]

In this paper we develop a fractional Hamilton-Jacobi formulation for discrete systems in terms of fractional Caputo derivatives. The fractional action function is obtained and the solutions of the equations of motion are recovered. An example is studied in details.

Eqab M. Rabei; Ibtesam Almayteh; Sami I. Muslih; Dumitru Baleanu

2007-03-26T23:59:59.000Z

372

• Relationships between Soil Microbial Biomass Determined by Chloroform Fumigation-Extraction, Substrate-Induced Respiration, and Phospholipid Fatty Acid Analysis  

SciTech Connect (OSTI)

ABSTRACT-The soil microbial biomass (SMB) is responsible for many of the cycles and transformations of nutrients in soils. Three methods of measuring and describing this pool in soil are: (1) chloroform fumigation-extraction (CFE), (2) substrate-induced respiration (SIR), and (3) total extractable phospholipid fatty acids (PLFA). This study was conducted to seek a relationship between microbial PLFA and measures of SMB. Microbial PLFA was best predicted by CFE (R2 = 0.77); 1 nmol of PLFA corresponded to a flush of 2.4 mg C released by fumigation. This conversion factor will be useful in discussions of microbial populations and diversity and allow comparisons to literature in which only CFE is used to describe the size of the microbial biomass.

Bailey, Vanessa L.; Peacock, A. D.; Smith, Jeff L.; Bolton, Harvey

2002-09-01T23:59:59.000Z

373

ECG-Derived Respiration and Instantaneous Frequency based on the Synchrosqueezing Transform: Application to Patients with Atrial Fibrillation  

E-Print Network [OSTI]

The acquisition of information about respiratory patterns without directly recording the respiratory signals would be beneficial in many clinical settings. The electrocardiogram (ECG)-derived respiration (EDR) algorithm, which derives the respiratory pattern by using the information encoded in ECG signals, enables data acquisition in this manner. However, the traditional EDR algorithm cannot be used in patients with atrial fibrillation (AF) because they have highly irregular heart rates. In this paper, we first provide a definition of ideal instantaneous frequency (IIF) of respiratory signals and then describe how a novel time-frequency representation technique referred to as the Synchrosqueezing transform (SST) was used for the accurate estimation of the IIF of respiratory signals, i.e., SST-IF. Then, we introduce a new EDR algorithm based on the evaluation of the SST-IF. We tested the applicability of our new EDR algorithm in patients with comorbid cardiovascular diseases, most of which were complicated by ...

Yi-Hsin, Chan; Shu-Shya, Hseu; Chi-Tai, Kuo; Yung-Hsin, Yeh

2011-01-01T23:59:59.000Z

374

RF Surface Impedance Characterization of Potential New Materials for SRF-based Accelerators  

SciTech Connect (OSTI)

In the development of new superconducting materials for possible use in SRF-based accelerators, it is useful to work with small candidate samples rather than complete resonant cavities. The recently commissioned Jefferson Lab RF Surface Impedance Characterization (SIC) system can presently characterize the central region of 50 mm diameter disk samples of various materials from 2 to 40 K exposed to RF magnetic fields up to 14 mT at 7.4 GHz. We report the recent measurement results of bulk Nb, thin film Nb on Cu and sapphire substrates, Nb{sub 3}Sn sample, and thin film MgB{sub 2} on sapphire substrate provided by colleagues at JLab and Temple University.

Xiao, Binping [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States) and College of William and Mary, Williamsburg, VA (United States); Eremeev, Grigory V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Phillips, H. Lawrence [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kelley, Michael J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2012-09-01T23:59:59.000Z

375

Permanent-magnet helicon sources and arrays: A new type of rf plasma  

SciTech Connect (OSTI)

Helicon discharges are known for their ability to produce high densities of partially ionized plasma, their efficiency arising from an unusual mechanism of rf coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small sources extend the use of helicons to the processing of large substrates. An eight-tube array was designed and constructed, and its density uniformity measured in a 53x165 cm{sup 2} chamber. Three innovations involved (a) the remote field of ring magnets, (b) a low-field density peak, and (c) rf power distribution. High-density plasmas uniform over large areas requires compatibility in all three areas.

Chen, Francis F.; Torreblanca, Humberto [University of California, Los Angeles, California 90095-1594 (United States)

2009-05-15T23:59:59.000Z

376

A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment  

SciTech Connect (OSTI)

MICE is a demonstration experiment for the ionization cooling of muon beams. Eight RF cavities are proposed to be used in the MICE cooling channel. These cavities will be operated in a strong magnetic field; therefore, they must be normal conducting. The cavity design and construction are based on the successful experience and techniques developed for a 201-MHz prototype cavity for the US MUCOOL program. Taking advantage of a muon beamâ s penetration property, the cavity employs a pair of curved thin beryllium windows to terminate conventional beam irises and achieve higher cavity shunt impedance. The cavity resembles a round, closed pillbox cavity. Two half-shells spun from copper sheets are joined by e-beam welding to form the cavity body. There are four ports on the cavity equator for RF couplers, vacuum pumping and field probes. The ports are formed by means of an extruding technique.

Li, D.; DeMello, A.J.; Virostek, Steve; S. Zisman, Michael; Rimmer, Robert

2008-07-01T23:59:59.000Z

377

A COMPACTRIO-BASED BEAM LOSS MONITOR FOR THE SNS RF TEST CAVE  

SciTech Connect (OSTI)

An RF Test Cave has been built at the Spallation Neutron Source (SNS) to be able to test RF cavities without interfering the SNS accelerator operations. In addition to using thick concrete wall to minimize radiation exposure, a Beam Loss Monitor (BLM) must abort the operation within 100 usec when the integrated radiation within the cave exceeds a threshold. We choose the CompactRIO platform to implement the BLM based on its performance, cost-effectiveness, and rapid development. Each in/output module is connected through an FPGA to provide point-by-point processing. Every 10 usec the data is acquired analyzed and compared to the threshold. Data from the FPGA is transferred using DMA to the real-time controller, which communicates to a gateway PC to talk to the SNS control system. The system includes diagnostics to test the hardware and integrates the losses in real-time. In this paper we describe our design, implementation, and results

Blokland, Willem [ORNL; Armstrong, Gary A [ORNL

2009-01-01T23:59:59.000Z

378

Enhancement of RF Breakdown Threshold of Microwave Cavities by Magnetic Insulation  

SciTech Connect (OSTI)

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.

Stratakis, D.; Gallardo, J.; Palmer, R.B.

2011-03-28T23:59:59.000Z

379

Elimination of Radio-Frequency Noise by Identifying and Diverting Large RF Ground Currents  

SciTech Connect (OSTI)

The problem of electromagnetic interference in scientific instruments is compounded for high-power plasma experiments by the large currents and voltages as well as by the broad bandwidths of the instruments. Ground loops are known to allow stray magnetic fields to drive large ground currents that can induce spurious signals and damage electronics. Furthermore, even when a ground loop is broken, capacitive coupling can still permit the flow of radio-frequency current, resulting in high-frequency spurious signals that can overwhelm the desired signal. We present the effects of RF ground loops on the output of vacuum photodiodes used in the Caltech Solar Loop Experiment and demonstrate the elimination of the spurious signals by diverting the ground currents away from the most vulnerable point of the signal line. Techniques for identifying the RF ground loops are also discussed. These techniques should be valuable in many high-power systems where interference from spurious coupling is an issue.

Perkins, R. J.; Bellan, P. M. [Applied Physics, California Institute of Technology (United States)

2011-12-23T23:59:59.000Z

380

Tests of an RF Dipole Crabbing Cavity for an Electron-Ion Collider  

SciTech Connect (OSTI)

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.

Castilla Loeza, Alejandro [ODU, JLAB; Delayen, Jean R. [ODU, JLAB

2013-12-01T23:59:59.000Z

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


381

RF heating efficiency of the terahertz superconducting hot-electron bolometer  

E-Print Network [OSTI]

We report results of the numerical solution by the Euler method of the system of heat balance equations written in recurrent form for the superconducting hot-electron bolometer (HEB) embedded in an electrical circuit. By taking into account the dependence of the HEB resistance on the transport current we have been able to calculate rigorously the RF heating efficiency, absorbed local oscillator (LO) power and conversion gain of the HEB mixer. We show that the calculated conversion gain is in excellent agreement with the experimental results, and that the substitution of the calculated RF heating efficiency and absorbed LO power into the expressions for the conversion gain and noise temperature given by the analytical small-signal model of the HEB yields excellent agreement with the corresponding measured values.

Maslennikov, Sergey

2014-01-01T23:59:59.000Z

382

Using rf impedance probe measurements to determine plasma potential and the electron energy distribution  

SciTech Connect (OSTI)

Earlier work has demonstrated the usefulness of a network analyzer in plasma diagnostics using spherical probes in the thin sheath limit. The rf signal applied to the probe by the network analyzer is small in magnitude compared to probe bias voltages, and the instrument returns both real and imaginary parts of the complex plasma impedance as a function of frequency for given bias voltages. This information can be used to determine sheath resistance, sheath density profiles, and a technique for measuring electron temperature. The present work outlines a method for finding plasma potential and the electron energy distribution within a limited energy range. The results are compared to those using conventional Langmuir probe techniques. The rf method has general application to diverse areas of plasma investigations when the plasma is uniform and probe dimensions are much less than the size of the plasma. These applications include laboratory and space environments.

Walker, D. N. [Global Strategies Group, Inc., Crofton, Maryland 21114 (United States); Fernsler, R. F.; Blackwell, D. D.; Amatucci, W. E. [Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave., Washington, DC 20375 (United States)

2010-11-15T23:59:59.000Z

383

JOURNAL DE PHYSIQUE Colloque C7, suppZ6ment au n07, Tome 40, Juillet 1979, nage C7-225 AN INVESTIGATIONON THE FREQUENCYCHARACTERISTICSOF THE RF DISCHARGEIN AR-HG MIXTURES  

E-Print Network [OSTI]

of discharges may exist sixultaneously In the .rf'discharges. In weakly Ionized plasma, the rf electric f i e l during the rf discharges. (2) fer these reasons, we study the breakaewn, arcing and maintezianca ~f, The brenkd~vonsf the discharge i s caused maiAly by the rf electric f i e l d (E discharge); hswerei

Paris-Sud XI, Université de

384

Design of a horizontal test cryostat for superconducting RF cavities for the FREIA facility at Uppsala University  

SciTech Connect (OSTI)

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.

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

385

Atmospheric Pressure RF (13.56 MHz) Glow Discharge: Characterization and Application to “In Line” Waste Water Treatment  

Science Journals Connector (OSTI)

In this work the results obtained from the experimental study of an Atmospheric Pressure Glow Discharge (APGD) appear, generated in Helium (He) and dry air mixture by using a radio frequency (RF 13.56 MHz) pow...

Jaime B. Castro; Marlon H. Guerra-Mutis…

2003-06-01T23:59:59.000Z

386

A comparative study of CH4 and CF4 rf discharges using a consistent plasma physics and chemistry simulator  

Science Journals Connector (OSTI)

A self-consistent, one-dimensional simulator for the physics and chemistry of radio frequency (rf) plasmas was developed and applied for CH4 and CF4. The simulator consists of a fluid model for the discharge phys...

Nikolaos V. Mantzaris; Evangelos Gogolides…

1996-09-01T23:59:59.000Z

387

Excitation frequency effects on atmospheric-pressure helium RF microplasmas: plasma density, electron energy and plasma impedance  

Science Journals Connector (OSTI)

...The effects of the driving RF frequency on the properties of low temperature atmospheric pressure helium microplasmas are discussed in light...?...m microdischarge driven at constant input power with a 10 MHz–...

K. McKay; F. Iza; M. G. Kong

2010-12-01T23:59:59.000Z

388

Time?differential radio?frequency muon spin resonance (TD?RF?SR) technique at a pulsed muon beam  

Science Journals Connector (OSTI)

Longitudinal?field ?SR methods, e.g., radio?frequency ?+...spin resonance (RF?SR), are well suited to investigate dynamic processes that destroy the phase coherence of the muon spin ensemble. Additional informati...

R. Scheuermann; J. Schmidl; A. Seeger; Th. Stammler; D. Herlach…

389

Fabrication process changes for performance improvement of an RF MEMS resonator : conformable contact lithography, Moiré alignment, and chlorine dry etching  

E-Print Network [OSTI]

This thesis presents fabrication process improvements for a RF MEMS resonator for the purpose of improving the quality factor (Q) and extending the frequency range. The process changes include the use of conformable contact ...

Sakai, Mark

2005-01-01T23:59:59.000Z

390

Uniform longitudinal beam profiles in the Fermilab Recycler using adaptive rf correction  

SciTech Connect (OSTI)

The Fermilab Recycler Ring is a permanent magnet based 8 GeV anti-proton storage ring. A wideband RF system, driven with ARB's (ARBitrary waveform generators), allows the system to produce programmable barrier waveforms. Beam current profile distortion was observed, its origin verified both experimentally and theoretically, and an FPGA-based correction system was designed, tested and implemented to level the bunch profile.

Hu, Martin; Broemmelsiek, Daniel Robert; Chase, Brian; Crisp, James L.; Eddy, Nathan; Joireman, Paul W.; Ng, King Yuen; /Fermilab

2007-06-01T23:59:59.000Z

391

A PARAMETRIC STUDY OF BCS RF SURFACE IMPEDANCE WITH MAGNETIC FIELD USING THE XIAO CODE  

SciTech Connect (OSTI)

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.

Reece, Charles E. [JLAB; Xiao, Binping [JLAB, BNL

2013-09-01T23:59:59.000Z

392

50 MW X-BAND RF SYSTEM FOR A PHOTOINJECTOR TEST STATION AT LLNL  

SciTech Connect (OSTI)

In support of X-band photoinjector development efforts at LLNL, a 50 MW test station is being constructed to investigate structure and photocathode optimization for future upgrades. A SLAC XL-4 klystron capable of generating 50 MW, 1.5 microsecond pulses will be the high power RF source for the system. Timing of the laser pulse on the photocathode with the applied RF field places very stringent requirements on phase jitter and drift. To achieve these requirements, the klystron will be powered by a state of the art, solid-state, high voltage modulator. The 50 MW will be divided between the photoinjector and a traveling wave accelerator section. A high power phase shifter is located between the photoinjector and accelerator section to adjust the phasing of the electron bunches with respect to the accelerating field. A variable attenuator is included on the input of the photoinjector. The distribution system including the various x-band components is being designed and constructed. In this paper, we will present the design, layout, and status of the RF system.

Marsh, R A; Anderson, S G; Barty, C J; Beer, G K; Cross, R R; Ebbers, C A; Gibson, D J; Hartemann, F V; Houck, T L; Adolphsen, C; Candel, A; Chu, T S; Jongewaard, E N; Li, Z; Raubenheimer, T; Tantawi, S G; Vlieks, A; Wang, F; Wang, J W; Zhou, F; Deis, G A

2011-03-11T23:59:59.000Z

393

An overview of the Low Energy Demonstration Accelerator (LEDA) project RF (radio frequency) systems  

SciTech Connect (OSTI)

Successful operation of the Accelerator Production of Tritium (APT) plant will require that accelerator downtime be kept to an absolute minimum. Over 230 separate 1 MW RF systems are expected to be used in the APT plant, making the efficiency and reliability of these systems two of the most critical factors in plant operation. The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory will serve as the prototype for APT. The design of the RF systems used in LEDA has been driven by the need for high efficiency and extremely high system reliability. The authors present details of the high voltage power supply and transmitter systems as well as detailed descriptions of the waveguide layout between the klystrons and the accelerating cavities. The first stage of LEDA operations will use four 1.2 MW klystrons to test the RFQ and supply power to one test stand. The RFQ will serve as a power combiner for multiple RF systems. They present some of the unique challenges expected in the use of this concept.

Bradley, J. III; Cummings, K.; Lynch, M.; Rees, D.; Roybal, W.; Tallerico, P. [Los Alamos National Lab., NM (United States); Toole, L. [Savannah River Site, SC (United States)

1997-05-12T23:59:59.000Z

394

Inductive current startup in large tokamaks with expanding minor radius and rf assist  

SciTech Connect (OSTI)

Auxiliary rf heating of electrons before and during the current-rise phase of a large tokamak, such as the Fusion Engineering Device (R = 4.8 m, a = 1.3 m, sigma = 1.6, B/sub T/ = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at approx. 90 GHz is used to create a small volume of high conductivity plasma (T/sub e/ approx. = 100 eV, n/sub e/ approx. = 10/sup 19/ m/sup -3/) near the upper hybrid resonance (UHR) region. This plasma conditioning permits a small radius (a/sub 0/ approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to approx. 100 V without rf assist). During the subsequent plasma expansion and current ramp phase, a combination of rf heating (up to 5 MW) and current profile control leads to a substantial savings in volt-seconds by: (1) minimizing the resistive flux consumption; and (2) maintaining the internal flux at or near the flat profile limit.

Borowski, S.K.

1984-02-01T23:59:59.000Z

395

Experiments with an rf dusty plasma and an external plasma jet  

SciTech Connect (OSTI)

A plasma jet produced in a coaxial plasma gun was aimed at a cloud of dust particles levitated in the sheath of a radio-frequency (rf) plasma produced between two parallel-plate electrodes. A high-speed camera with a side-view on the dust cloud was used to track the dust particles. Several cases of dust motion could be observed. When the jet was parallel with the horizontal electrodes of the rf plasma the dust particles were either pushed out of the trapping region by the plasma jet or were only perturbed from their equilibrium position, oscillating with a frequency of the order of a few kHz. In the first case the trajectory of the dust particles followed the curvature of the sheath. In the second case, when the jet was fired at a small angle with the horizontal electrodes the dust particles hit the bottom electrode and ricocheted back into the sheath. Finally, another situation was observed when the jet perturbed the rf plasma and its sheath and the whole dust crystal fell to the electrode.

Ticos, C. M. [National Institute for Lasers, Plasma and Radiation Physics, 077125 Bucharest (Romania)

2010-12-14T23:59:59.000Z

396

Design of a new VHF RF power amplifier system for LANSCE  

SciTech Connect (OSTI)

A major upgrade is replacing much of the 40 year-old proton drift tube linac RF system with new components at the Los Alamos Neutron Science Center (LANSCE). When installed, the new system will reduce the total number of electron power tubes from twenty-four to eight in the RF powerplant. A new 200 MHz high power cavity amplifier has being developed at LANSCE. This 3.2 MW final power amplifier (FPA) uses a Thales TH628 Diacrode{reg_sign}, a state-of-the-art tetrode that eliminates the large anode modulator of the triode-based FPA that has been in use for four decades. Drive power for the FPA is provided by a new tetrode intermediate power amplifier (and a solid-state driver stage). The new system has sufficient duty-factor capability to allow LANSCE to return to 1 MW beam operation. Prototype RF power amplifiers have been designed, fabricated, and assembled, and are being tested. High voltage DC power became available through innovative re-engineering of an installed system. Details of the electrical and mechanical design of the FPA and ancillary systems are discussed.

Lyles, John T M [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

397

rf system for the Los Alamos free-electron laser (FEL)  

SciTech Connect (OSTI)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 ..mu..s at a 1-pps rate. The phase and amplitude stability requirements are +-1/2/sup 0/, and +-1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, 10-..mu..s pulses. Each tube has delivered over 3.6-MW, 100-..mu..s pulses in the FEL system.

Friedrichs, C.C.; Tallerico, P.J.; Hoffert, W.J.

1983-01-01T23:59:59.000Z

398

rf Plasma Heating in a Mirror Machine at Frequencies near the Ion Cyclotron Frequency and its Harmonics  

Science Journals Connector (OSTI)

By applying 75 kW of pulsed rf power to a decaying hydrogen plasma following turbulent heating, we have maintained a plasma density of 1012 to 5 × 1012 cm-3 for the 600-? sec duration of the rf pulse. Neutral energy analyzer measurements of ion temperature indicate Ti?100 eV, while diamagnetic loop measurements indicate 100 eVrf signals near the harmonics of the ion cyclotron frequency.

D. G. Swanson; R. W. Clark; P. Korn; S. Robertson; C. B. Wharton

1972-04-17T23:59:59.000Z

399

A type of hyperelliptic continued fraction. Based on hints of Tschebychev, a continued fraction is described  

E-Print Network [OSTI]

to this as the classical CFE. See [1], Tschebychev (loc. cit.), [12], and for more recent accounts [2, 3, 4, 18 CFE. The fraction detects the torsion, when finite, of D - D- and D - W, where W is any divisor, because of symmetries analogous to those of the classical CFE, it can be expected to run about twice

Berry, Thomas

400

Experimental Investigation of RF Sheath Rectification in ICRF and LH Heated Plasmas on Alcator C-Mod  

SciTech Connect (OSTI)

Radio frequency (RF) rectification of the plasma sheath is being actively studied on C-Mod as a likely mechanism that leads to prohibitively high molybdenum levels in the plasma core of ion cyclotron RF (ICRF) heated discharges. We installed emissive, ion sensitive, Langmuir, and 3-D B-dot probes to quantify the plasma potentials ({Phi}{sub P}) in ICRF and lower hybrid (LH) heated discharges. Two probe sets were mounted on fixed limiter surfaces and one set of probes was mounted on a reciprocating (along the major radius) probe. Initial results showed that RF rectification is strongly dependent on the local plasma density and not on the local RF fields. The RF sheaths had a threshold-like appearance at the local density of {approx}10{sup 16} m-{sup 3}. Radial probe scans revealed that the RF sheaths peaked in the vicinity of the ICRF limiter surface, agreeing with a recent theory. The highest {Phi}{sub P}'s were observed on magnetic field lines directly mapped to the active ICRF antenna. Measurements in LH heated plasmas showed a strong {Phi}{sub P} dependence on the parallel index of refraction n{sub ||} of the launched LH waves: {Phi}{sub P} is greater at lower n{sub ||}. Little dependence was observed on the local plasma density.

Ochoukov, R.; Whyte, D. G.; Faust, I.; LaBombard, B.; Lipschultz, B.; Meneghini, O.; Wallace, G.; Wukitch, S. [MIT Plasma Science and Fusion Center, Cambridge (United States); Myra, J. [Lodestar Research Corporation, Boulder, Colorado (United States)

2011-12-23T23:59:59.000Z

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


401

Development of a bellows chamber with a comb-type RF shield for high-current accelerators  

Science Journals Connector (OSTI)

An all-metal bellows chamber with a comb-type Radio Frequency (RF) shield for a high-current accelerator was developed and tested at the KEK B-factory (KEKB). The comb-type RF shield has no thin fingers but has nested comb teeth instead at an inner surface. The comb-type RF-shield has a higher thermal strength structurally compared to the conventional finger-type one. Leakage of the TE mode like HOM through the RF shield is almost suppressed. Two test models of bellows chambers installed in the 3.5 GeV positron ring of KEKB showed good properties up to a stored beam current of 1.5 A. The temperature rise of the corrugation was about 7°C and the temperature rise was about 16 of that of the bellows chamber with a conventional finger-type RF shield located under the same condition. The temperature rise of the comb teeth was about 22°C, while that of fingers of the finger-type RF shield was estimated to be about 105°C for the equivalent HOM power. No vacuum arcing was detected during beam operation.

Y. Suetsugu; M. Shirai; K. Shibata; K. Murata; M. Kaneko; K. Sakamoto; K. Sugisaki; M. Kawahara

2004-01-01T23:59:59.000Z

402

Fundamentals of Biomass Pretreatment by Fractionation  

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

Fundamentals of Biomass Pretreatment by Fractionation Poulomi Sannigrahi 1,2 and Arthur J. Ragauskas 1,2,3 1 BioEnergy Science Center, Oak Ridge, USA 2 Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, USA 3 School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, USA 10.1 Introduction With the rise in global energy demand and environmental concerns about the use of fossil fuels, the need for rapid development of alternative fuels from sustainable, non-food sources is now well acknowledged. The effective utilization of low-cost high-volume agricultural and forest biomass for the production of transporta- tion fuels and bio-based materials will play a vital role in addressing this concern [1]. The processing of lignocellulosic biomass, especially from mixed agricultural and forest sources with varying composition,

403

Release fractions for Rocky Flats specific accidents  

SciTech Connect (OSTI)

As Rocky Flats and other DOE facilities begin the transition process towards decommissioning, the nature of the scenarios to be studied in safety analysis will change. Whereas the previous emphasis in safety accidents related to production, now the emphasis is shifting to accidents related tc decommissioning and waste management. Accident scenarios of concern at Rocky Flats now include situations of a different nature and different scale than are represented by most of the existing experimental accident data. This presentation will discuss approaches@to use for applying the existing body of release fraction data to this new emphasis. Mention will also be made of ongoing efforts to produce new data and improve the understanding of physical mechanisms involved.

Weiss, R.C.

1992-09-01T23:59:59.000Z

404

Release fractions for Rocky Flats specific accidents  

SciTech Connect (OSTI)

As Rocky Flats and other DOE facilities begin the transition process towards decommissioning, the nature of the scenarios to be studied in safety analysis will change. Whereas the previous emphasis in safety accidents related to production, now the emphasis is shifting to accidents related tc decommissioning and waste management. Accident scenarios of concern at Rocky Flats now include situations of a different nature and different scale than are represented by most of the existing experimental accident data. This presentation will discuss approaches to use for applying the existing body of release fraction data to this new emphasis. Mention will also be made of ongoing efforts to produce new data and improve the understanding of physical mechanisms involved.

Weiss, R.C.

1992-01-01T23:59:59.000Z

405

Multidimensional optical fractionation with holographic verification  

E-Print Network [OSTI]

The trajectories of colloidal particles driven through a periodic potential energy landscape can become kinetically locked in to directions dictated by the landscape's symmetries. When the landscape is realized with forces exerted by a structured light field, the path a given particle follows has been predicted to depend exquisitely sensitively on such properties as the particle's size and refractive index These predictions, however, have not been tested experimentally. Here, we describe measurements of colloidal silica spheres' transport through arrays of holographic optical traps that use holographic video microscopy to track individual spheres' motions in three dimensions and simultaneously to measure each sphere's radius and refractive index with part-per-thousand resolution. These measurements confirm previously untested predictions for the threshold of kinetically locked-in transport, and demonstrate the ability of optical fractionation to sort colloidal spheres with part-per-thousand resolution on multiple characteristics simultaneously.

Ke Xiao; David G. Grier

2009-12-23T23:59:59.000Z

406

Anomalous Topological Pumps and Fractional Josephson Effects  

E-Print Network [OSTI]

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.

Fan Zhang; C. L. Kane

2013-10-20T23:59:59.000Z

407

Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas  

Science Journals Connector (OSTI)

A laser initiation and radio frequency (rf) sustainment technique has been developed and improved from our previous work to create and sustain large-volume high-pressure air and nitrogen plasmas. This technique utilizes a laser-initiated 15 mTorr partial pressure tetrakis (dimethylamino) ethylene seed plasma with a 75 Torr background gas pressure to achieve high-pressure air/nitrogen plasma breakdown and reduce the rf power requirement needed to sustain the plasma. Upon the laser plasma initiation the chamber pressure is raised to 760 Torr in 0.5 s through a pulsed gas valve and the end of the chamber is subsequently opened to the ambient air. The atmospheric-pressure plasma is then maintained with the 13.56 MHz rf power. Using this technique large-volume ( 1000 ? cm 3 ) high electron density (on the order of 10 11 – 12 ? cm ? 3 ) 760 Torr air and nitrogen plasmas have been created while rf power reflection is minimized during the entire plasma pulse utilizing a dynamic matching method. This plasma can project far away from the antenna region (30 cm) and the rf power budget is 5 ? W / cm 3 . Temporal evolution of the plasma electron density and total electron-neutral collision frequency during the pulsed plasma is diagnosed using millimeter waveinterferometry. Optical emission spectroscopy(OES) aided by SPECAIR a special OES simulation program for air-constituent plasmas is used to analyze the radiating species and thermodynamic characteristics of the plasma. Rotational and vibrational temperatures of 4400 – 4600 ± 100 ? K are obtained from the emission spectra from the N 2 ( 2 + ) and N 2 + ( 1 ? ) transitions by matching the experimental spectrum results with the SPECAIR simulation results. Based on the relation between the electron collision frequency and the neutral density utilizing millimeter waveinterferometry the electron temperature of the 760 Torr nitrogen plasma is found to be 8700 ± 100 ? K ( 0.75 ± 0.1 ? eV ) . Therefore the plasma deviates significantly from local thermal equilibrium.

Siqi Luo; C. Mark Denning; John E. Scharer

2008-01-01T23:59:59.000Z

408

Laser-rf creation and diagnostics of seeded atmospheric pressure air and nitrogen plasmas  

SciTech Connect (OSTI)

A laser initiation and radio frequency (rf) sustainment technique has been developed and improved from our previous work to create and sustain large-volume, high-pressure air and nitrogen plasmas. This technique utilizes a laser-initiated, 15 mTorr partial pressure tetrakis (dimethylamino) ethylene seed plasma with a 75 Torr background gas pressure to achieve high-pressure air/nitrogen plasma breakdown and reduce the rf power requirement needed to sustain the plasma. Upon the laser plasma initiation, the chamber pressure is raised to 760 Torr in 0.5 s through a pulsed gas valve, and the end of the chamber is subsequently opened to the ambient air. The atmospheric-pressure plasma is then maintained with the 13.56 MHz rf power. Using this technique, large-volume (1000 cm{sup 3}), high electron density (on the order of 10{sup 11-12} cm{sup -3}), 760 Torr air and nitrogen plasmas have been created while rf power reflection is minimized during the entire plasma pulse utilizing a dynamic matching method. This plasma can project far away from the antenna region (30 cm), and the rf power budget is 5 W/cm{sup 3}. Temporal evolution of the plasma electron density and total electron-neutral collision frequency during the pulsed plasma is diagnosed using millimeter wave interferometry. Optical emission spectroscopy (OES) aided by SPECAIR, a special OES simulation program for air-constituent plasmas, is used to analyze the radiating species and thermodynamic characteristics of the plasma. Rotational and vibrational temperatures of 4400-4600{+-}100 K are obtained from the emission spectra from the N{sub 2}(2+) and N{sub 2}{sup +}(1-) transitions by matching the experimental spectrum results with the SPECAIR simulation results. Based on the relation between the electron collision frequency and the neutral density, utilizing millimeter wave interferometry, the electron temperature of the 760 Torr nitrogen plasma is found to be 8700{+-}100 K (0.75{+-}0.1 eV). Therefore, the plasma deviates significantly from local thermal equilibrium.

Luo Siqi; Denning, C. Mark; Scharer, John E. [Electrical and Computer Engineering, University of Wisconsin--Madison, Madison, Wisconsin 53705 (United States)

2008-07-01T23:59:59.000Z

409

CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results  

SciTech Connect (OSTI)

Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 {+-} 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 {+-} 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 {+-} 13.6 min and 43.7 {+-} 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 {+-} 8.8 months, local recurrence-free survival was 14.4 {+-} 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 {+-} 16.6 ml/min/1.73 m{sup 2} before RF ablation vs. 47.2 {+-} 11.9 ml/min/1.73 m{sup 2} after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Lemm, G.; Hohenstein, E. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany); Bellemann, N.; Stampfl, U. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Goezen, A. S.; Rassweiler, J. [Clinic for Urology, SLK Kliniken Heilbronn GmbH (Germany); Kauczor, H. U.; Radeleff, B. A. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Pereira, P. L. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany)

2013-06-15T23:59:59.000Z

410

Fractional Equations of Kicked Systems and Discrete Maps  

E-Print Network [OSTI]

Starting from kicked equations of motion with derivatives of non-integer orders, we obtain "fractional" discrete maps. These maps are generalizations of well-known universal, standard, dissipative, kicked damped rotator maps. The main property of the suggested fractional maps is a long-term memory. The memory effects in the fractional discrete maps mean that their present state evolution depends on all past states with special forms of weights. These forms are represented by combinations of power-law functions.

Vasily E. Tarasov; George M. Zaslavsky

2011-07-20T23:59:59.000Z

411

Projective synchronization in fractional order chaotic systems and its control  

E-Print Network [OSTI]

The chaotic dynamics of fractional (non-integer) order systems have begun to attract much attention in recent years. In this paper, we study the projective synchronization in two coupled fractional order chaotic oscillators. It is shown that projective synchronization can also exist in coupled fractional order chaotic systems. A simple feedback control method for controlling the scaling factor onto a desired value is also presented.

Chunguang Li

2006-04-24T23:59:59.000Z

412

Fractional entropy decay and the third law of thermodynamics  

Science Journals Connector (OSTI)

We report in this paper a theoretical study on the quantum thermodynamic properties of a fractional damping system. Through the analysis, few nontrivial characteristics are revealed, which include (1) a fractional power-law decay entropy function, which provides an evidence for the validity of the third law of thermodynamics in the quantum dissipative region and (2) the varying of the entropy from a nonlinear divergent function to a semilinear decay function with a fractional exponent as the temperature approaches absolute zero.

Chun-Yang Wang; Xue-Mei Zong; Hong Zhang; Ming Yi

2014-08-21T23:59:59.000Z

413

Fractional Order Transmission Line Modeling and Parameter Identification.  

E-Print Network [OSTI]

??Fractional order calculus (FOC) has wide applications in modeling natural behavior of systems related to different areas of engineering including bioengineering, viscoelasticity, electronics, robotics, control… (more)

Razib, Mohammad Yeasin

2010-01-01T23:59:59.000Z

414

Tunable fractional quantum Hall phases in bilayer graphene  

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

Coulomb interactions drive the existence of a correlated many-body state. Bilayer graphene represents a particularly interesting material in which to study the fractional...

415

Linear Stochastic Fractional Programming with Sum-of-Probabilistic ...  

E-Print Network [OSTI]

Fractional Programming Problem with Mixed Constraints”, Acta Ciencia Indica,. Vol. XXX M, No. 3, pp 497-506. 11. Charles, V., and Dutta, D., “Extremization of ...

2005-04-19T23:59:59.000Z

416

Determination of Charm Hadronic Branching Fractions at CLEO-c  

E-Print Network [OSTI]

Recent results from CLEO-c on measurements of absolute hadronic branching fractions of D0, D+, and Ds+ mesons are presented.

A. Ryd

2007-11-24T23:59:59.000Z

417

Electromagnetic design of the RF cavity beam position monitor for the LCLS.  

SciTech Connect (OSTI)

A high-resolution X-band cavity BPM has been developed for the LCLS. A dipole mode cavity and a monopole mode reference cavity have been designed in order to achieve micron-level accuracy of the beam position. The rf properties of the BPM as well as beam interaction with the cavities will be discussed including output power and tuning. In addition, methods will be presented for improving the isolation of the output ports to differentiate between horizontal/vertical beam motion and to reject extraneous modes from affecting the output signal. The predicted simulation results will be compared to data collected from low-power experimental tests.

Waldschmidt, G.; Lill, B.; Morrison, L.

2008-01-01T23:59:59.000Z

418

Rf-plasma synthesis of nanosize silicon carbide and nitride. Final report  

SciTech Connect (OSTI)

A pulsed rf plasma technique is capable of generating ceramic particles of 10 manometer dimension. Experiments using silane/ammonia and trimethylchlorosilane/hydrogen gas mixtures show that both silicon nitride and silicon carbide powders can be synthesized with control of the average particle diameter from 7 to 200 nm. Large size dispersion and much agglomeration appear characteristic of the method, in contrast to results reported by another research group. The as produced powders have a high hydrogen content and are air and moisture sensitive. Post-plasma treatment in a controlled atmosphere at elevated temperature (800{degrees}C) eliminates the hydrogen and stabilizes the powder with respect to oxidation or hydrolysis.

Buss, R.J.

1997-02-01T23:59:59.000Z

419

Beam manipulation and compression using broadband rf systems in the Fermilab Main Injector and Recycler  

SciTech Connect (OSTI)

A novel method for beam manipulation, compression, and stacking using a broad band RF system in circular accelerators is described. The method uses a series of linear voltage ramps in combination with moving barrier pulses to azimuthally compress, expand, or cog the beam. Beam manipulations can be accomplished rapidly and, in principle, without emittance growth. The general principle of the method is discussed using beam dynamics simulations. Beam experiments in the Fermilab Recycler Ring convincingly validate the concept. Preliminary experiments in the Fermilab Main Injector to investigate its potential for merging two ''booster batches'' to produce high intensity proton beams for neutrino and antiproton production are described.

G William Foster et al.

2004-07-09T23:59:59.000Z

420

Development of an rf driven multicusp ion source for nuclear science experiments  

Science Journals Connector (OSTI)

A compact 13.56 \\{MHz\\} radio-frequency (rf) driven multicusp ion source is under development at Lawrence Berkeley National Laboratory (LBNL) for radioactive ion beam applications. In this paper we describe the ion source design and the general ion source performance using H2, Ar, Xe gas and a 90% Ar/10% CO gas mixture for generating the discharge plasma. The following ion source characteristics have been analyzed: extractable ion current, ion species distributions, ionization efficiency for nobel gases, axial energy spread and ion beam emittance measurements. This ion source can generate ion current densities of approximately 60 mA/cm2.

D Wutte; S Freedman; R Gough; Y Lee; M Leitner; K.N Leung; C Lyneis; D.S Pickard; M.D Williams; Z.Q Xie

1998-01-01T23:59:59.000Z

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


421

Electrochemical Performance of rf Magnetron Sputtered LiCoO{sub 2} Thin Film Positive Electrodes  

SciTech Connect (OSTI)

Thin films of LiCoO{sub 2} were grown by rf magnetron sputtering technique and studied the influence of In situ annealing treatment on microstructural and electrochemical properties of the films. Annealing treatment in presence of O{sub 2} ambient develops characteristic (104) plan in relative to (003) plane texture indicating that the films have HT-layered structure with R3-bar m symmetry. The effect is discussed in terms of grain size, cycling stability, reversibility and the specific discharge capacity.

Kumar, P. Jeevan; Babu, K. Jayanth; Hussain, O. M. [Thin Film Laboratory, Department of Physics, Sri Venkateswara University, TIRUPATI-517 502 (India)

2010-12-01T23:59:59.000Z

422

Structural and optical properties of zinc oxide film using RF-sputtering technique  

SciTech Connect (OSTI)

This paper reports the fabrication of zinc oxide (ZnO) film using RF-sputtering technique. Determination of the structural properties using High Resolution X-ray Diffraction (HRXRD) confirmed that ZnO film deposited on silicon (Si) substrate has a high quality. This result is in line with the Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) which were used to image the morphology of the film, in which a rough surface was demonstrated. Photoluminescence (PL) emission is included to study the optical properties of ZnO film that shows two PL peak in the UV region at 371 nm and in visible region at 530 nm respectively.

Hashim, A. J.; Jaafar, M. S.; Ghazai, Alaa J. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 Pinang (Malaysia); Physics Department, Science College, Thi-Qar University (Iraq)

2012-11-27T23:59:59.000Z

423

Fabrication of super-hydrophobic surfaces on aluminum alloy substrates by RF-sputtered polytetrafluoroethylene coatings  

SciTech Connect (OSTI)

In this work, we present a method of fabricating super-hydrophobic surface on aluminum alloy substrate. The etching of aluminum surfaces has been performed using Beck's dislocation etchant for different time to create micrometer-sized irregular steps. An optimised etching time of 50 s is found to be essential before polytetrafluoroethylene (PTFE) coating, to obtain a highest water contact angle of 165±2° with a lowest contact angle hysteresis as low as 5±2°. The presence of patterned microstructure as revealed by scanning electron microscopy (SEM) together with the low surface energy ultrathin RF-sputtered PTFE films renders the aluminum alloy surfaces highly super-hydrophobic.

Wang, Yang; Liu, Xiao Wei; Zhang, Hai Feng, E-mail: wy3121685@163.com; Zhou, Zhi Ping [Department of Microelectronics, Harbin Institute of Technology, Harbin, Heilongjiang, 150001 (China)] [Department of Microelectronics, Harbin Institute of Technology, Harbin, Heilongjiang, 150001 (China)

2014-03-15T23:59:59.000Z

424

On the scaling of rf and dc self-bias voltages with pressure in electronegative capacitively coupled plasmas  

SciTech Connect (OSTI)

Higher gas densities and lower diffusion losses at higher operating pressures typically lead to increased charged species densities (and hence flux) for a constant power deposition in capacitively coupled plasmas (CCP). As a result, one would expect that the bias radio-frequency (rf) voltage required to deposit a given power in a CCP reactor decreases with increasing operating pressure. These observations may not hold true in multiple frequency CCPs, commonly used for dielectric etching in microelectronics fabrication, due to nonlinear interactions between the rf sources. Wafer-based measurements of the rf and self-generated direct current (dc) bias voltages in a dual-frequency capacitively coupled electronegative plasma were made, which indicate that the rf and dc voltages vary nonmonotonically with pressure. These experimental results are presented in this paper and a computational plasma model is used to explain the experimental observations for varying 60 MHz and 13 MHz powers in the Ar/CF{sub 4}/CHF{sub 3} plasma over a pressure range of 25 to 400 mTorr. The authors found that while the ion density increases with pressure, the increase is most dominant near the electrode with the high frequency source (60 MHz). The rf and dc bias voltages are ultimately influenced by both charged species density magnitudes and spatial profiles.

Agarwal, Ankur; Dorf, Leonid; Rauf, Shahid; Collins, Ken [Applied Materials Inc., 974 E. Arques Avenue, M/S 81312, Sunnyvale, California 94085 (United States)

2012-03-15T23:59:59.000Z

425

Isotope Fractionation of Water during Evaporation without Condensation  

Science Journals Connector (OSTI)

Specifially, isotope fractionation factors associated with free evaporation (?evap) have been measured as a function of the isotopic composition and temperature of the liquid. ... Liquid-vapor fractionation of oxygen and hydrogen isotopes of water from the freezing to the critical temperature ...

Christopher D. Cappa; Walter S. Drisdell; Jared D. Smith; Richard J. Saykally; Ronald C. Cohen

2005-12-03T23:59:59.000Z

426

Explicit and implicit finite difference schemes for fractional Cattaneo equation  

Science Journals Connector (OSTI)

In this paper, the numerical solution of fractional (non-integer)-order Cattaneo equation for describing anomalous diffusion has been investigated. Two finite difference schemes namely an explicit predictor-corrector and totally implicit schemes have ... Keywords: Convergence rate, Finite difference schemes, Fractional Cattaneo equation, Stability

H. R. Ghazizadeh; M. Maerefat; A. Azimi

2010-09-01T23:59:59.000Z

427

SVC Voltage Regulator Based on Fractional Order PID  

Science Journals Connector (OSTI)

Contradiction exist between rapid and smooth in the dynamic adjustment process of SVC, however, Fractional order PID controller has two degrees of freedom more than the integer order PID controller, and it has better control performance. This article ... Keywords: SVC, Fractional order PID, Voltage regulator, Oustaloup

Manyu Liu; Huaying Dong; Guishu Liang

2012-12-01T23:59:59.000Z

428

Third harmonic cavity design and RF measurements for the Frascati DA?NE collider  

Science Journals Connector (OSTI)

Third harmonic passive RF cavities have been proposed for installation in both rings of the DA?NE factory collider to improve the Touschek lifetime and to increase the Landau damping. This paper illustrates the design of the harmonic cavities. The main requirements were to obtain a relatively low R/Q factor and a quality factor Q as high as possible to satisfy beam dynamics requirements and to damp all the higher order mode (HOM) to a harmless level in order to avoid multibunch instabilities. A spherical shape of the cavity central body has been chosen as an optimum compromise between a high Q resonator and a low R/Q factor. HOM suppression has been provided by a ferrite ring damper designed for the superconducting cavities of the high energy ring of the KEK-B factory. The design and electromagnetic properties of the resonant modes have been studied with MAFIA and HFSS codes. Cavities have been made of aluminum and the RF measurements have been performed to characterize them. The measurements are in a good agreement with numerical simulations results, demonstrating a satisfactory HOM damping.

David Alesini; Roberto Boni; Alessandro Gallo; Fabio Marcellini; Mikhail Zobov; Mauro Migliorati; Luigi Palumbo

2004-09-07T23:59:59.000Z

429

A Numerical Treatment of the Rf SQUID: I. General Properties andNoise Energy  

SciTech Connect (OSTI)

We investigate the characteristics and noise performance of rf Superconducting Quantum Interference Devices (SQUIDs) by solving the corresponding Langevin equations numerically and optimizing the model parameters with respect to noise energy. After introducing the basic concepts of the numerical simulations, we give a detailed discussion of the performance of the SQUID as a function of all relevant parameters. The best performance is obtained in the crossover region between the dispersive and dissipative regimes, characterized by an inductance parameter {beta}{prime}{sub L} {triple_bond} 2{pi}LI{sub 0}/{Phi}{sub 0} {approx} 1; L is the loop inductance, I{sub 0} the critical current of the Josephson junction, and {phi}{sub 0} the flux quantum. In this regime, which is not well explored by previous analytical approaches, the lowest (intrinsic) values of noise energy are a factor of about 2 above previous estimates based on analytical approaches. However, several other analytical predictions, such as the inverse proportionality of the noise energy on the tank circuit quality factor and the square of the coupling coefficient between the tank circuit and the SQUID loop, could not be well reproduced. The optimized intrinsic noise energy of the rf SQUID is superior to that of the dc SQUID at all temperatures. Although for technologically achievable parameters this advantage shrinks, particularly at low thermal fluctuation levels, we give an example for realistic parameters that leads to a noise energy comparable to that of the dc SQUID even in this regime.

Kleiner, Reinhold; Koelle, Dieter; Clarke, John

2007-01-15T23:59:59.000Z

430

Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab  

SciTech Connect (OSTI)

The Advanced Superconducting Test Accelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beam lines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

Leibfritz, J.; Andrews, R.; Baffes, C.M.; Carlson, K.; Chase, B.; Church, M.D.; Harms, E.R.; Klebaner, A.L.; Kucera, M.; Martinez, A.; Nagaitsev, S.; /Fermilab

2012-05-01T23:59:59.000Z

431

Time dependent evolution of RF-generated non-thermal particle distributions in fusion plasmas  

Science Journals Connector (OSTI)

We describe fully self-consistent time-dependent simulations of radio frequency (RF) generated ion distributions in the ion cyclotron range of frequencies and RF-generated electron distributions in the lower hybrid range of frequencies using combined Fokker–Planck and full wave electromagnetic field solvers. In each regime, the non-thermal particle distributions have been used in synthetic diagnostic codes to compare with diagnostic measurements from experiment, thus providing validation of the simulation capability. The computational intensive simulations require multiple full wave code runs that iterate with a Fokker–Planck code. We will discuss advanced algorithms that have been implemented to accelerate both the massively parallel full wave simulations as well as the iteration with the distribution code. A vector extrapolation method (Sidi A 2008 Comput. Math. Appl. 56) that permits Jacobian-free acceleration of the traditional fixed point iteration technique is used to reduce the number of iterations needed between the distribution and wave codes to converge to self-consistency. The computational burden of the parallel full wave codes has been reduced by using a more efficient two level parallel decomposition that improves the strong scaling of the codes and reduces the communication overhead.

J C Wright; A Bader; L A Berry; P T Bonoli; R W Harvey; E F Jaeger; J-P Lee; A Schmidt; E D'Azevedo; I Faust; C K Phillips; E Valeo

2014-01-01T23:59:59.000Z

432

Plasma processing of large curved surfaces for superconducting rf cavity modification  

SciTech Connect (OSTI)

Plasma based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. The development of the technology based on Cl2/Ar plasma etching has to address several crucial parameters which influence the etching rate and surface roughness, and eventually, determine cavity performance. This includes dependence of the process on the frequency of the RF generator, gas pressure, power level, the driven (inner) electrode configuration, and the chlorine concentration in the gas mixture during plasma processing. To demonstrate surface layer removal in the asymmetric non-planar geometry, we are using a simple cylindrical cavity with 8 ports symmetrically distributed over the cylinder. The ports are used for diagnosing the plasma parameters and as holders for the samples to be etched. The etching rate is highly correlated with the shape of the inner electrode, radio-frequency (RF) circuit elements, chlorine concentration in the Cl2/Ar gas mixtures, residence time of reactive species and temperature of the cavity. Using cylindrical electrodes with variable radius, large-surface ring-shaped samples and d.c. bias implementation in the external circuit we have demonstrated substantial average etching rates and outlined the possibility to optimize plasma properties with respect to maximum surface processing effect.

Upadhyay, J.; Im, Do; Popovi??, S.; Valente-Feliciano, A.-M.; Phillips, L.; Vuskovic, L

2014-12-01T23:59:59.000Z

433

Robert B. Laughlin and the Fractional Quantum Hall Effect  

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

Robert B. Laughlin and the Fractional Quantum Hall Effect Robert B. Laughlin and the Fractional Quantum Hall Effect Resources with Additional Information Robert B. Laughlin Photo Courtesy of LLNL Robert B. Laughlin shared the 1998 Nobel Prize in Physics with Horst L. Störmer and Daniel C. Tsui for 'their discovery of a new form of quantum fluid with fractionally charged excitations'. ' ... [I]n 1982 ... Störmer and Tsui discovered the effect. In 1983, Laughlin, then at the Lawrence Livermore National Laboratory, provided the theoretical explanation of the effect in terms of fractionally charged particles. It was a "confluence of things from engineering that prepared me for understanding the fractional quantum Hall effect and coming up with an explanation," Laughlin said during a television interview at Stanford. ...

434

A Matlab toolbox for fractional relaxation-oscillation equations  

E-Print Network [OSTI]

Stress relaxation and oscillation damping of complex viscoelastic media often manifest history- and path-dependent physical behaviors and cannot accurately be described by the classical models. Recent research found that fractional derivative models can characterize such complex relaxation and damping. However, to our best knowledge, easy-to-use numerical software is not available for fractional relaxation-oscillation (FRO) equations. This paper is to introduce an open source free Matlab toolbox which we developed in recent years for numerical solution of the FRO equations. This FRO toolbox uses the predictor-corrector approach for the discretization of time fractional derivative, and non-expert users can accurately solve fractional relaxation-oscillation equations via a friendly graphical user interface. Compared with experimental data, our numerical experiments show that the FRO toolbox is highly efficient and accurate to simulate viscoelastic stress relaxation and damped vibration. This free toolbox will help promote the research and practical use of fractional relaxation-oscillation equations.

Song Wei; Wen Chen

2013-02-14T23:59:59.000Z

435

Use of the Far Infrared Tangential Interferometer/Polarimeter diagnostic for the study of rf driven plasma waves on NSTX  

SciTech Connect (OSTI)

A rf detection system for waves in the 30 MHz range has been constructed for the Far Infrared Tangential Interferometer/Polarimeter on National Spherical Torus Experiment (NSTX). It is aimed at monitoring high frequency density fluctuations driven by 30 MHz high harmonic fast wave fields. The levels of density fluctuations at various radial chords and antenna phase angles can be estimated using the electric field calculated by TORIC code and linearized continuity equation for the electron density. In this paper, the experimental arrangement for the detection of rf signal and preliminary results of simulation will be discussed.

Kim, J.; Park, H. [Department of Physics, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Lee, K. C.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Kaita, R.; Phillips, C. K.; Valeo, E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Bonoli, P. T. [Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts (United States)

2010-10-15T23:59:59.000Z

436

500 MW X-Band RF System of a 0.25 GeV Electron LINAC for Advanced Compton Scattering Source Application  

SciTech Connect (OSTI)

A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with the SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

Chu, Tak Sum; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Marsh, Roark; /LLNL, Livermore; Siders, Craig; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

2012-07-03T23:59:59.000Z

437

2052 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 35. NO. II, NOVEMBER 1988 Design of the Laser-Driven RF Electron Gun for the  

E-Print Network [OSTI]

-Driven RF Electron Gun for the BNL Accelerator Test Facility KIRK T. McDONALD Abstract-The BNL electron gun due to the effects of space-charge and nonlinear RF fields. The design of the gun was aided diagram of the linac and laser components. Here we report on the design of the electron gun

McDonald, Kirk

438

THE RF-GUN BASED INJECTOR FOR THE TESLA TESTFACILITY LINAC S. Schreiber for the TESLA Collaboration, DESY, 22603 Hamburg, Germany  

E-Print Network [OSTI]

THE RF-GUN BASED INJECTOR FOR THE TESLA TESTFACILITY LINAC S. Schreiber for the TESLA Collaboration was produced by a subharmonic injector using a thermionic gun, a buncher cavity, and one standard Linear Collider, a laser driven RF gun is required. At present, two similar guns are under con- struction

439

A Theory for the RF Surface Field for Various Metals at the Destructive Breakdown Limit  

SciTech Connect (OSTI)

By destructive breakdown we mean a breakdown event that results in surface melting over a macroscopic area in a high E-field region of an accelerator structure. A plasma forms over the molten area, bombarding the surface with an intense ion current ({approx} 10{sup 8} A/cm{sup 2}), equivalent to a pressure of about a thousand Atmospheres. This pressure in turn causes molten copper to migrate away from the iris tip, resulting in measurable changes in the iris shape. The breakdown process can be roughly divided into four stages: (1) the formation of ''plasma spots'' at field emission sites, each spot leaving a crater-like footprint; (2) crater clustering, and the formation of areas with hundreds of overlapping craters; (3) surface melting in the region of a crater cluster; (4) the process after surface melting that leads to destructive breakdown. The physics underlying each of these stages is developed, and a comparison is made between the theory and experimental evidence whenever possible. The key to preventing breakdown lies in stage (3). A single plasma spot emits a current of several amperes, a portion of which returns to impact the surrounding area with a power density on the order 10{sup 7} Watt/cm{sup 2}. This power density is not quite adequate to melt the surrounding surface on a time scale short compared to the rf pulse length. In a crater field, however, the impact areas from multiple plasma spots overlap to provide sufficient power density for surface melting over an area on the order of 0.1 mm{sup 2} or more. The key to preventing breakdown is to choose an iris tip material that requires the highest power density (proportional to the square of the rf surface field) for surface melting, taking into account the penetration depth of the impacting electrons. The rf surface field required for surface melting (relative to copper) has been calculated for a large number elementary metals, plus stainless-steel and carbon.

Wilson, Perry B.; /SLAC

2007-03-06T23:59:59.000Z

440

Proc. of the workshop on pushing the limits of RF superconductivity.  

SciTech Connect (OSTI)

For three days in late September last year, some sixty experts in RF superconductivity from around the world came together at Argonne to discuss how to push the limits of RF superconductivity for particle accelerators. It was an intense workshop with in-depth presentations and ample discussions. There was added excitement due to the fact that, a few days before the workshop, the International Technology Recommendation Panel had decided in favor of superconducting technology for the International Linear Collider (ILC), the next major high-energy physics accelerator project. Superconducting RF technology is also important for other large accelerator projects that are either imminent or under active discussion at this time, such as the Rare Isotope Accelerator (RIA) for nuclear physics, energy recovery linacs (ERLs), and x-ray free-electron lasers. For these accelerators, the capability in maximum accelerating gradient and/or the Q value is essential to limit the length and/or operating cost of the accelerators. The technological progress of superconducting accelerators during the past two decades has been truly remarkable, both in low-frequency structures for acceleration of protons and ions as well as in high-frequency structures for electrons. The requirements of future accelerators demand an even higher level of performance. The topics of this workshop are therefore highly relevant and timely. The presentations given at the workshop contained authoritative reviews of the current state of the art as well as some original materials that previously had not been widely circulated. We therefore felt strongly that these materials should be put together in the form of a workshop proceeding. The outcome is this report, which consists of two parts: first, a collection of the scholarly papers prepared by some of the participants and second, copies of the viewgraphs of all presentations. The presentation viewgraphs, in full color, are also available from the Workshop Presentations link on the workshop's web page at http://www.aps.anl.gov/conferences/RFSCLimits/. I would like to thank all of the participants for their lively contributions to the workshop and to these proceedings, and Helen Edwards and Hasan Padamsee for their help in developing the workshop program. I also thank Cathy Eyberger, Kelly Jaje, and Renee Lanham for working very hard to take care of the administrative details, in particular Cathy for editing this report.

Kim, K-J., Eyberger, C., editors

2005-04-13T23:59:59.000Z

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


441

High Gradient Acceleration in a 17 GHz Photocathode RF Gun* S. C. Chen, J. Gonichon, 1;. C-L. Lin, R. J. Temkin, S. Trotz, B. G. Danly, and J. S. Wurtele  

E-Print Network [OSTI]

High Gradient Acceleration in a 17 GHz Photocathode RF Gun* S. C. Chen, J. Gonichon, 1;. C-L. Lin.icle acceleration at high mi- ccowave (RF) frequencies are under study at hIIT. The 17 GHz photocathode RF gun has, efforts have been made recent,ly t,o creat,e novel electron beam sources.[l] While existing RF guns

Wurtele, Jonathan

442

Behavior of the TTF2 RF Gun with long pulses and high repetition rates J. Baehr1, I. Bohnet1, J.-P. Carneiro2, K. Floettmann2, J. H. Han1, M. v. Hartrott3,  

E-Print Network [OSTI]

Behavior of the TTF2 RF Gun with long pulses and high repetition rates J. Baehr1, I. Bohnet1, J the behavior of the TTF2 RF gun with long RF pulses (up to 900 µs), high peak power (up to 3 MW) and high Zeuthen from January to March 2003, where the RF gun has been tested prior to its installation at DESY

443

WAVEGUIDE BROAD-WALL COUPLING FOR RF GUNS Leon C.-L. Lin, S. C. Chen, and J. S. Wurtele  

E-Print Network [OSTI]

approximation and appropriate Green's functions. (4) The dipole radiation is used to calculate the reflection problem shown in Fig. 1. The RF energy is coupled into the cavity through two apertures which are assumed and the cavity. These tensors are readily obtained from the Green's functionsof the waveguide and pillboxcavities

Wurtele, Jonathan

444

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81  

E-Print Network [OSTI]

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81 Springer­Verlag Berlin Heidelberg 1996 Density functional theory of time­dependent phenomena E of density functional theory (DFT) is to describe an interacting many­particle system exclusively

Gross, E.K.U.

445

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81  

E-Print Network [OSTI]

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81 Springer-Verlag Berlin Heidelberg 1996 Density functional theory of time-dependent phenomena E of density functional theory (DFT) is to describe an interacting many-particle system exclusively

Gross, E.K.U.

446

One-Step Production of Superhydrophobic Coatings on Flat Substrates via Atmospheric Rf Plasma Process Using Non-Fluorinated Hydrocarbons  

Science Journals Connector (OSTI)

One-Step Production of Superhydrophobic Coatings on Flat Substrates via Atmospheric Rf Plasma Process Using Non-Fluorinated Hydrocarbons ... This paper describes the direct deposition of hydrocarbon coatings with a static water contact angle higher than 150 using simple C6 hydrocarbons as a reactive gas in helium plasma generated in ambient air without any preroughening of the silicon (100) substrate. ...

Seul Hee Lee; Zachary R. Dilworth; Erik Hsiao; Anna L. Barnette; Matthew Marino; Jeong Hoon Kim; Jung-Gu Kang; Tae-Hwan Jung; Seong H. Kim

2011-01-31T23:59:59.000Z

447

In conventional accelerators, energy from RF electro-magnetic waves in vacuum is transformed into kinetic energy  

E-Print Network [OSTI]

In conventional accelerators, energy from RF electro- magnetic waves in vacuum is transformed for accelerating and storing countercirculating beams of 7-TeV protons, has a stored beam energy exceeding 300 MJ. Accelerator-based light sources rely on the fact that when beams of GeV electrons interact with magnetic

Geddes, Cameron Guy Robinson

448

FeCoCr nanocomposites for application in self-regulated rf heating K. J. Miller,1,a  

E-Print Network [OSTI]

Fe­Co­Cr nanocomposites for application in self-regulated rf heating K. J. Miller,1,a A. Colletti,1, appropriate for ferrofluid cooling and self-regulated heating applications. These alloys have low Curie temperatures, moderate magnetic moments and provide increased heat capacity in a liquid used in a thermal cycle

McHenry, Michael E.

449

Utilizing RF-I and Intelligent Scheduling for Better Throughput/Watt in a Mobile GPU Memory System  

E-Print Network [OSTI]

Utilizing RF-I and Intelligent Scheduling for Better Throughput/Watt in a Mobile GPU Memory System system is essential for the mobile GPU. In this article, we propose to improve throughput/watt are able to improve throughput 17% up to 66% while increasing throughput per watt by an average of 18% up

Cong, Jason "Jingsheng"

450

Publications in refereed journals 115. Krajnovic, D., ..., Peletier, R.F., et al. 2008, MNRAS, 390, 93  

E-Print Network [OSTI]

, R. F., Falc´on-Barroso, J., Bacon, R., et al. 2007, MNRAS, 379, 445 106. Cappellari, M. Falc´on-Barroso, J., Bacon, R., Bureau, M., ..., Peletier, R.F., et al. 2006, MNRAS, 369, 529 87., Falc´on-Barroso, J., Peletier, R. F., Cappellari, M., Emsellem, E., McDermid, R. M., de Zeeuw, P. T

Peletier, Reynier

451

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens, Steven Okamoto and Katia Sycara  

E-Print Network [OSTI]

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens, Steven Okamoto The rapidly improving availability of small, unmanned aerial vehicles (UAVs) and their ever reducing cost is leading to considerable interest in multi-UAV applications. How- ever, while UAVs have become smaller

Scerri, Paul

452

Plasma physics : ion energy in RF plasma etching Office National d'Etudes et de Recherches Arospatiales, 92320 Chtillon, France  

E-Print Network [OSTI]

etching. - The discharges currently in use for etching are RF capacitive discharges, for example in CF4 or a mixture of CF4 and 02, at a pressure of between 0.1 and 1 mbar, and at a frequency ĂşJ/2n in the 1-30 MHz

Paris-Sud XI, Université de

453

Synthesis of a material for semiconductor applications: Boron oxynitride prepared by low frequency rf plasma-assisted metalorganic chemical  

E-Print Network [OSTI]

rf plasma-assisted metalorganic chemical vapor deposition G. C. Chen, D.-C. Lim, S.-B. Lee, and J-derived plasma-assisted metalorganic chemical vapor deposition MOCVD , and have studied the electrical compounds have become promising functional materials for integrated circuits, flash memories, and solar

Boo, Jin-Hyo

454

A Comparison of Magnesium and Beryllium Acceptors in GaN Grown by rf-Plasma Assisted Molecular Beam Epitaxy  

E-Print Network [OSTI]

A Comparison of Magnesium and Beryllium Acceptors in GaN Grown by rf-Plasma Assisted Molecular Beam Evans and Associates, Sunnyvale, CA 94086 ABSTRACT Step-doped structures of both magnesium and beryllium activation energy of approximately 100 meV. INTRODUCTION While magnesium is currently the most

Myers, Tom

455

Multi-walled carbon nanotubes on amorphous carbon films R.F. Klie a,*, D. Ciuparu b  

E-Print Network [OSTI]

Multi-walled carbon nanotubes on amorphous carbon films R.F. Klie a,*, D. Ciuparu b , L. Pfefferle, that are inherent to the production process of the amorphous carbon support films, used for both SEM and TEM studies appear in both commercial as well as homemade holey carbon support films on copper grids, and suggest

Harris, Peter J F

456

Excitation and propagation of Electrostatic Ion Cyclotron waves in rf-sustained plasmas of interest to propulsion research  

E-Print Network [OSTI]

an efficient way to increase ion temperature. Methods such as the Ion Cyclotron Range Heating (ICRH), LowerExcitation and propagation of Electrostatic Ion Cyclotron waves in rf-sustained plasmas of interest Jersey 08544 AIAA-2004-4095 July 11-14, 2004 Excitation and propagation of Electrostatic Ion Cyclotron

Choueiri, Edgar

457

Towards a 3D time dependent Fokker-Planck solver for modelling RF heating in realistic tokamak geometry  

E-Print Network [OSTI]

. Hedin, Ion Cyclotron Heating in Toroidal Plasmas, Ph.D. thesis, Royal Institute of Technology StockholmTowards a 3D time dependent Fokker-Planck solver for modelling RF heating in realistic tokamak supercomputers and the need for predictive tools to guide the experiments, modelling radio frequency heating

458

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: II. THE ROLE OF COLLISIONS AND NON-LINEAR EFFECTS  

E-Print Network [OSTI]

. The similar problem of cyclotron heating were extensively analyzed for magnetic traps (see for example review8COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: II. THE ROLE OF COLLISIONS AND NON of electrons ( ) is large (comparable with discharge slab) and collisionless heating dominates Ohmic one. Being

Kaganovich, Igor

459

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 55, NO. 4, APRIL 2007 1193 Frequency Tunable Microstrip Patch Antenna Using RF  

E-Print Network [OSTI]

Microstrip Patch Antenna Using RF MEMS Technology Emre Erdil, Kagan Topalli, Mehmet Unlu, Ozlem Aydin Civi, and Tayfun Akin Abstract--A novel reconfigurable microstrip patch antenna is presented that is monolithically. Reconfigurability of the operating frequency of the microstrip patch antenna is achieved by loading

Akin, Tayfun

460

Simulation of non-linear rf losses derived from characteristic Nb topography  

SciTech Connect (OSTI)

A simplified model has been developed to simulate non-linear RF losses on Nb surfaces exclusively due to topographical enhancement of surface magnetic fields. If local sharp edges are small enough, at locations where local surface fields exceed Hc, small volumes of material may become normal conducting without thermal leading to quench. These small volumes of normal material yield increases in the effective surface resistance of the Nb. Using topographic data from typical BCP?d and EP?d fine grain niobium surfaces, we have simulated field-dependent losses and found that when extrapolated to resulting cavity performance, these losses correspond well to characteristic BCP/EP high field Q0 performance differences for fine grain Nb. We describe the structure of the model, its limitations, and the effects of this type of non-linear loss contribution on SRF cavities.

Reece, Charles E. [JLAB; Xu, Chen; Kelley, Michael [W& M. JLAB

2013-09-01T23:59:59.000Z

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


461

High deposition rate preparation of amorphous silicon solar cells by rf glow discharge decomposition of disilane  

SciTech Connect (OSTI)

The optical and electrical properties of hydrogenated amorphous silicon films produced by rf glow discharge decomposition of disilane diluted in helium (Si/sub 2/H/sub 6//He = 1/9) have been studied while systematically varying the film deposition rate. The properties and composition of the films were monitored by measuring the optical band gap, IR vibrational spectrum, dark conductivity, and the photoconductivity as a function of the deposition rate. The photoluminescence of the high deposition rate films gave a peak at 1.33 eV. These films, whose properties are rather similar to those of the conventional a-Si:H films prepared from monosilane, have been used to fabricate nip-type a-Si:H solar cells. At a deposition rate of 11 A/sec, a conversion efficiency of 6.86% was obtained. This high efficiency shows that disilane is applicable for mass production fabrication of a-Si:H solar cells.

Kenne, J.; Ohashi, Y.; Matsushita, T.; Konagai, M.; Takahashi, K.

1984-01-15T23:59:59.000Z

462

Longitudinal beam dynamics simulation in electron rings in strong rf focusing regime  

Science Journals Connector (OSTI)

Obtaining very short bunches in an electron storage ring is one of the frontiers of the accelerator physics. The strong rf focusing (SRFF) is a way to have short bunches at a given position in the ring, thanks to the principle of the bunch length modulation. Until now, the bunch length modulation has been studied only in the limit of zero current; in this paper we present the results of a simulation code suitable to study the effects of coherent synchrotron radiation and vacuum chamber wakefields on the single bunch longitudinal dynamics in the SRFF regime . The code has been applied to three different lattices that can be realized in the Frascati e+/e- collider DA?NE for a possible experiment on bunch length modulation.

Luciano Falbo; David Alesini; Mauro Migliorati

2006-09-13T23:59:59.000Z

463

A new methodology for determining recombination parameters using an RF photoconductance instrument  

SciTech Connect (OSTI)

Measurements of minority-carrier lifetime in silicon wafers provide an effective technique for process control and device-physics optimization. For example, detailed measurements of minority-carrier lifetime vs. injection level can allow a nearly complete experimental optimization of a solar cell design and process. This extended abstract describes a methodology that allows this fully characterization by using a relatively simple RF photoconductance-decay tool. By analyzing the quasi-steady-state photoconductance as a function of incident light intensity, information corresponding to an I{sub sc}-V{sub oc} curve can be obtained from a non-contacted silicon wafer. This information is available at various stages during the solar cell fabrication process. The use of steady-state photoconductance instead of transient photoconductance makes use of simple electronics and light sources, yet it has the capability to measure lifetimes down into the 100 ns range.

Sinton, R.A.; Cuevas, A. [Australian National Univ., Canberra (Australia)

1995-08-01T23:59:59.000Z

464

An RF-only ion-funnel for extraction from high-pressure gases  

E-Print Network [OSTI]

An RF ion-funnel technique has been developed to extract ions from a high-pressure (10 bar) noble-gas environment into vacuum ($10^{-6}$ mbar). Detailed simulations have been performed and a prototype has been developed for the purpose of extracting $^{136}$Ba ions from Xe gas with high efficiency. With this prototype, ions have been extracted for the first time from high-pressure xenon gas and argon gas. Systematic studies have been carried out and compared to the simulations. This demonstration of extraction of ions with mass comparable to that of the gas generating the high-pressure into vacuum has applications to Ba tagging from a Xe-gas time-projection chamber (TPC) for double beta decay as well as to the general problem of recovering trace amounts of an ionized element in a heavy (m$>40$ u) carrier gas.

Thomas Brunner; Daniel Fudenberg; Victor Varentsov; Amanda Sabourov; Giorgio Gratta; Jens Dilling; Ralph DeVoe; David Sinclair; William Fairbank Jr.; Joshua B Albert; David J Auty; Phil S Barbeau; Douglas Beck; Cesar Benitez-Medina; Martin Breidenbach; Guofu F Cao; Christopher Chambers; Bruce Cleveland; Matthew Coon; Adam Craycraft; Timothy Daniels; Sean J Daugherty; Tamar Didberidze; Michelle J Dolinski; Matthew Dunford; Lorenzo Fabris; Jacques Farine; Wolfhart Feldmeier; Peter Fierlinger; Razvan Gornea; Kevin Graham; Mike Heffner; Mitchell Hughes; Michael Jewell; Xiaoshan S Jiang; Tessa N Johnson; Sereres Johnston; Alexander Karelin; Lisa J Kaufman; Ryan Killick; Thomas Koffas; Scott Kravitz; Reiner Kruecken; Alexey Kuchenkov; Krishna S Kumar; Douglas S Leonard; Francois Leonard; Caio Licciardi; Yi-Hsuan H Lin; Jiajie Ling; Ryan MacLellan; Michael G Marino; Brian Mong; David Moore; Allen Odian; Igor Ostrovskiy; Christian Ouellet; Andreas Piepke; Andrea Pocar; Fabrice Retiere; Peter C Rowson; Maria P Rozo; Alexis Schubert; Erica Smith; Victor Stekhanov; Michal Tarka; Tamer Tolba; Delia Tosi; Karl Twelker; Jean-Luc L Vuilleumier; Josiah Walton; Timothy Walton; Manuel Weber; Liangjian J Wen; Ubi Wichoski; Liang Yang; Yung-Ruey Yen

2014-12-03T23:59:59.000Z

465

New phenomena observed by EISCAT during an RF ionospheric modification experiment  

SciTech Connect (OSTI)

An ionospheric RF-modification experiment was carried out using the MPI heating facility and the EISCAT 933-MHz incoherent scatter radar (ISR). The MPI heater was normally operated at 4.04 MHz and modulated 20-s on, 40-s off. The ISR observed waves propagating parallel to B0, and chirped as well as normal plasma line observations were performed. Heater-induced plasma lines were observed only in the first 10-s integration interval, indicating a strong overshoot. These lines are unusual in that multiple simultaneous lines were observed, normally originating within one kilometer of the critical region but sometimes from lower heights, and that the frequency of the most common line is offset some 250 kHz from the heating frequency, with the other lines occurring at greater frequency offsets. Ion power profile observations show the existence of a topside enhanced ion line at the critical density corresponding to the heater frequency. 9 refs.

Isham, B.; Hagfors, T.; Kofman, W.; Thide, B.; Nordling, J. (Cornell Univ., Ithaca, NY (USA) Centre d'Etudes des Phenomenes Aleatoires et Geophysiques, Saint-Martin-d'Heres (France) Institutet for Rymdfysik, Uppsala (Sweden))

1990-06-01T23:59:59.000Z

466

Nuclear-Magnetic-Resonance Line Narrowing by a Rotating rf Field  

Science Journals Connector (OSTI)

A nuclear-magnetic-resonance method is explored, which effectively attenuates the dipolar interaction in solids. The experimental technique corresponds to the observation of a free-induction decay in a frame of reference rotating with the frequency of an applied rf field. When the amplitude H1 of this field is much greater than the local field in the solid, and when its frequency is appropriately chosen, the secular part of the dipolar interaction is removed. As a result the rotary saturation line is extremely narrowed. At smaller values of H1, nonsecular terms in the dipolar interaction come into play and contribute to line broadening. These nonsecular effects are investigated both theoretically and experimentally. All the measurements were made in single crystals of calcium fluoride. The calculation of the nonsecular contribution to the line width utilizes the unitary transformation method of Jordhal and Pryce. Theory and experiment are in good agreement.

Moses Lee and Walter I. Goldburg

1965-11-15T23:59:59.000Z

467

Thin film deposition of barium strontium oxide by rf magnetron sputtering  

SciTech Connect (OSTI)

Barium strontium oxide [(BaSr)O] thin films approximately 1 {mu}m in thickness were deposited on tungsten substrates using rf magnetron sputter deposition for thermionic cathode applications. Three substrate temperatures ranging from 25 to 700 deg. C were used in the deposition processes to create oxide films with different surface morphologies and crystalline structures. The films were characterized with scanning electron microscopy and their surface morphologies were correlated to their thermionic emission properties. The results showed that the surface morphology and crystalline structure of the oxide films strongly affected the emission properties. The oxide film deposited at the lowest substrate temperature of 25 deg. C showed a rough surface and a crystalline structure consisting of nanograins. At higher substrate temperatures, the oxide films exhibited smooth surfaces and close-packed crystalline structures with larger grains. The work function of the oxide films was reduced and the emission current density increased as a result of the increase in the growth temperature. The (BaSr)O film made at 700 deg. C exhibited the lowest work function of 1.57 eV and the largest emission current density of 1.60 A/cm{sup 2} at 1198 K under an electrical field of 0.88 V/{mu}m. The emission current density and the work function of the (BaSr)O thin film cathodes were stable over the testing period of 8 h. Compared to the traditional cathode fabrication process, which involves the coating of carbonates followed by an activation process, rf magnetron sputtering has a greater ability to control the deposition parameters, which makes it a valuable alternative technique to fabricate oxide cathodes.

Liu Yan; Day, Christopher M.; Little, Scott A.; Jin, Feng [Department of Physics and Astronomy, Ball State University, Muncie, Indiana 47306 (United States)

2006-11-15T23:59:59.000Z

468

A BIFURCATION RESULT FOR NON-LOCAL FRACTIONAL EQUATIONS  

E-Print Network [OSTI]

, minimal surfaces, materials science and water waves. This is one of the reason why, recently, non studied non-local fractional Laplacian equations with superlinear and subcritical or critical

469

On fractional differential inclusions with the Jumarie derivative  

SciTech Connect (OSTI)

In the paper, fractional differential inclusions with the Jumarie derivative are studied. We discuss the existence and uniqueness of a solution to such problems. Our study relies on standard variational methods.

Kamocki, Rafa?, E-mail: rafkam@math.uni.lodz.pl [Faculty of Mathematics and Computer Science, Chair of Differential Equations and Computer Science, University of Lodz, Banacha 22, 90-238 Lodz (Poland)] [Faculty of Mathematics and Computer Science, Chair of Differential Equations and Computer Science, University of Lodz, Banacha 22, 90-238 Lodz (Poland); Obczy?ski, Cezary, E-mail: czacza@math.uni.lodz.pl [Faculty of Mathematics and Computer Science, Chair of Nonlinear Analysis, University of Lodz, Banacha 22, 90-238 Lodz (Poland)] [Faculty of Mathematics and Computer Science, Chair of Nonlinear Analysis, University of Lodz, Banacha 22, 90-238 Lodz (Poland)

2014-02-15T23:59:59.000Z

470

Deriving emissions time series from sparse atmospheric mole fractions  

E-Print Network [OSTI]

A growth-based Bayesian inverse method is presented for deriving emissions of atmospheric trace species from temporally sparse measurements of their mole fractions. This work is motivated by many recent studies that have ...

Rigby, Matthew

471

Measurement of the Topological Branching Fractions of the ? Lepton  

E-Print Network [OSTI]

We report new and precise measurements of the decay branching fractions of the ? lepton to one and three charged particles. The data, corresponding to an integrated luminosity of 176 pb(?1), were collected by the high ...

Baringer, Philip S.

1985-08-05T23:59:59.000Z

472

Energy Efficiency in Cryogenic Fractionation Through Distributive Distillation  

E-Print Network [OSTI]

-down and cryogenic fractionation steps, the technology can significantly reduce refrigeration power requirements. ARS technology can be applied to revamps of existing plants as well as new plant designs. Additional applications are now being considered...

Carradine, C. R.; McCue, R. H.

473

On the Functional Relation Between Quality Factor and Fractional Bandwidth  

E-Print Network [OSTI]

The functional relation between the fractional band-width and the quality factor of a radiating system is investigated in this note. Several widely used definitions of the quality factor are compared on two examples of RLC circuits that serve as a simplified model of a single resonant antenna tuned to its resonance. It is demonstrated that for a first-order system, only the quality factor based on differentiation of input impedance has unique proportionality to the fractional bandwidth, whereas e.g. the classical definition of the quality factor, i. e. the ratio of the stored energy to the lost energy per one cycle, is not uniquely proportional to the fractional bandwidth. In addition, it is shown that for higher-order systems the quality factor based on differentiation of the input impedance ceases to be uniquely related to the fractional bandwidth.

Capek, Miloslav; Hazdra, Pavel

2014-01-01T23:59:59.000Z

474

Gravity duals of fractional branes in various dimensions  

SciTech Connect (OSTI)

We derive type II supergravity solutions corresponding to space-filling regular and fractional D branes on (9{minus}p)-dimensional conical transverse spaces. Fractional Dp-branes are wrapped D(p+2)-branes; therefore, our solutions exist only if the base of the cone has a non-vanishing Betti number b{sub 2}. We also consider 11-dimensional SUGRA solutions corresponding to regular and fractional M2 branes on 8-dimensional cones whose base has a non-vanishing b{sub 3}. In this case a fractional M2-brane is an M5-brane wrapped over a 3-cycle. We discuss the gauge theory intepretation of these solutions, as well as of the solutions constructed by Cvetic and co-workers.

Herzog, Christopher P.; Klebanov, Igor R.

2001-06-15T23:59:59.000Z

475

NGL fractionators planned for Corpus Christi olefins plant  

Science Journals Connector (OSTI)

TexStar MidStream Services LP is to install two natural gas liquids (NGL) fractionation units adjacent to LyondellBasell affiliate Equistar Chemicals LP's plant in Corpus Christi, Texas, USA.

2013-01-01T23:59:59.000Z

476

RESEARCH Open Access Gene expression and fractionation resistance  

E-Print Network [OSTI]

in Paramecium, Gout et al. [10] identify a clear relationship between high WGD duplicate gene retention rates for explaining variable resistance to fractionation. The Gout et al. paper [10] is the primary inspiration

Sankoff, David

477

Sunlight creates oxygenated species in water-soluble fractions...  

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

a t Sunlight creates oxygenated species in water-soluble fractions of Deepwater horizon oil Phoebe Z. Ray a , Huan Chen b , David C. Podgorski b,c , Amy M. McKenna b , Matthew A....

478

Lattice construction of pseudopotential Hamiltonians for fractional Chern insulators  

Science Journals Connector (OSTI)

Fractional Chern insulators are novel realizations of fractional quantum Hall states in lattice systems without orbital magnetic field. These states can be mapped onto conventional fractional quantum Hall states through the Wannier state representation [Qi, Phys. Rev. Lett. 107, 126803 (2011)]. In this paper, we use the Wannier state representation to construct the pseudopotential Hamiltonians for fractional Chern insulators, which are interaction Hamiltonians with certain ideal model wave functions as exact ground states. We show that these pseudopotential Hamiltonians can be approximated by short-ranged interactions in fractional Chern insulators, and that their range will be minimized by an optimal gauge choice for the Wannier states. As illustrative examples, we explicitly write down the form of the lowest pseudopotential for several fractional Chern insulator models like the lattice Dirac model, the checkerboard model with Chern number 1, the d-wave model, and the triangular lattice model with Chern number 2. The proposed pseudopotential Hamiltonians have the 1/3 Laughlin state as their ground state when the Chern number C1=1, and a topological nematic (330) state as their ground state when C1=2. Also included are the results of an interpolation between the d-wave model and two decoupled layers of lattice Dirac models, which explicitly demonstrate the relation between C1=2 fractional Chern insulators and bilayer fractional quantum Hall states. The proposed states can be verified by future numerical works and, in particular, provide a model Hamiltonian for the topological nematic states that have not been realized numerically.

Ching Hua Lee and Xiao-Liang Qi

2014-08-06T23:59:59.000Z

479

Characterization and fractionation by ultrafiltration of guayule resin  

E-Print Network [OSTI]

Rubber Production. 2. Solute Flow Through GPC Column. 3. Comparison of UF, MF, and RO Processes. 4. Pressure Gradient in Tubular Membrane. 5. Flow Pattern for Hollow Tube Asymmetric UF Membranes. 6. Structure of an Asymmetric Tubular Membrane. 7... information from the GPC analysis, indicates which compounds were present in each fraction. Identification and separation of potentially valuable fractions in the resin would increase the overall market value of the guayule shrub. Ultrafiltration (UF...

Daly, Monica Ann

2012-06-07T23:59:59.000Z

480

Baytown Xylene Fractionation Energy Reduction using Dynamic Matrix Control (DMC)  

E-Print Network [OSTI]

Baytown Xylene Fractionation Energy Reduction using Dynamic Matrix Control (DMC) IETC 2014 New Orleans, Louisiana David Hokanson ExxonMobil Research and Engineering May 22, 2014 ESL-IE-14-05-33 Proceedings of the Thrity-Sixth Industrial Energy... Technology Conference New Orleans, LA. May 20-23, 2014 2Outline • Baytown Chemical Complex • Xylene Fractionation Overview • Dynamic Matrix Control • Results • Benefits/Wrap-Up ESL-IE-14-05-33 Proceedings of the Thrity-Sixth Industrial Energy Technology...

Hokanson, D.

2014-01-01T23:59:59.000Z

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481

Crystal-symmetry preserving Wannier states for fractional Chern insulators  

Science Journals Connector (OSTI)

Recently, many numerical evidences of fractional Chern insulator, i.e., the fractional quantum Hall states on lattices, are proposed when a Chern band is partially filled. Some trial wave functions of fractional Chern insulators can be obtained by mapping the fractional quantum Hall wave functions defined in the continuum onto the lattice through the Wannier state representation [Phys. Rev. Lett. 107, 126803 (2011)] in which the single particle Landau orbits in the Landau levels are identified with the one-dimensional Wannier states of the Chern bands with Chern number C=1. However, this mapping generically breaks the lattice point group symmetry. In this paper we discuss a general approach of modifying the mapping to accommodate the lattice rotational symmetry. The wave functions constructed through this modified mapping should serve as better trial wave functions in the thermodynamical limit and on the rotationally invariant finite lattice. Also these wave functions will form a good basis for the construction of lattice symmetry preserving pseudopotential formalism for fractional Chern insulators. The focus of this paper shall be mainly on the C4 rotational symmetry of square lattices. Similar analysis can be straightforwardly generalized to triangular or hexagonal lattices with C6 symmetry. We also generalize the discussion to the lattice symmetry of fractional Chern insulators with high Chern number bands.

Chao-Ming Jian and Xiao-Liang Qi

2013-10-25T23:59:59.000Z

482

Investigating the Role of Respiration in Plant Salinity Tolerance by Analyzing Mitochondrial Proteomes from Wheat and a Salinity-Tolerant Amphiploid (Wheat × Lophopyrum elongatum)  

Science Journals Connector (OSTI)

For instance, a plant’s capacity to exclude Na+ ions is strongly linked to its rate of root respiration,(8, 9) due to the energetic costs associated with actively transporting Na+ and Cl– ions against concentration gradients. ... This could suggest that root tissue was undergoing a more severe salinity scenario due to direct physical contact between root tissue and the saline nutrient solution or that root mitochondria are endowed with a greater flexibility at the protein level. ... Mitochondria from pea leaves were purified by centrifugation on a self-generated Percoll gradient which contained a linear gradient of polyvinylpyrrolidone (0-10%, wt./vol.). ...

Richard P. Jacoby; A. Harvey Millar; Nicolas L. Taylor

2013-07-29T23:59:59.000Z

483

Assimilation and respiration of radioactive ethylene glycol, in the presence of high sodium chloride concentrations, by a sodium chloride requiring bacterium  

E-Print Network [OSTI]

containing 2 gm ethylene glycol and salts in 250 ml of distilled H20 which was started with a small inoculum of 2 ml suspension (11. 8 mg dry wt) removed 1. 96 gm glycol in 136 hr. Use of a nitrogen-limited medium allowed most of the ethylene glycol... growth on ethylene glycol or propylene glycol favored oxidation of ethylene glycol over glucose while prior growth on glucose favored oxidation of glucose over the iv glycols. Age of the culture had no dramatic effect on the rate of respiration...

Gonzalez, Carlos Francisco

2012-06-07T23:59:59.000Z

484

Model of Fractionalization of Faraday Lines in Compact Electrodynamics  

E-Print Network [OSTI]

Motivated by ideas of fractionalization and intrinsic topological order in bosonic models with short-range interactions, we consider similar phenomena in formal lattice gauge theory models. Specifically, we show that a compact quantum electrodynamics (CQED) can have, besides the familiar Coulomb and confined phases, additional unusual confined phases where excitations are quantum lines carrying fractions of the elementary unit of electric field strength. We construct a model that has $N$-tupled monopole condensation and realizes $1/N$ fractionalization of the quantum Faraday lines. This phase has another excitation which is a $Z_N$ quantum surface in spatial dimensions five and higher, but can be viewed as a quantum line or a quantum particle in four or three spatial dimensions respectively. These excitation have statistical interactions with the fractionalized Faraday lines; for example, in three spatial dimensions, the particle excitation picks up a Berry phase of $e^{i2\\pi/N}$ when going around the fractionalized Faraday line excitation. We demonstrate the existence of this phase by Monte Carlo simulations in (3+1) space-time dimensions.

Scott D. Geraedts; Olexei I. Motrunich

2014-08-13T23:59:59.000Z

485

Colloquium: Fractional calculus view of complexity: A tutorial  

Science Journals Connector (OSTI)

The fractional calculus has been part of the mathematics and science literature for 310 years. However, it is only in the past decade or so that it has drawn the attention of mainstream science as a way to describe the dynamics of complex phenomena with long-term memory, spatial heterogeneity, along with nonstationary and nonergodic statistics. The most recent application encompasses complex networks, which require new ways of thinking about the world. Part of the new cognition is provided by the fractional calculus description of temporal and topological complexity. Consequently, this Colloquium is not so much a tutorial on the mathematics of the fractional calculus as it is an exploration of how complex phenomena in the physical, social, and life sciences that have eluded traditional mathematical modeling become less mysterious when certain historical assumptions such as differentiability are discarded and the ordinary calculus is replaced with the fractional calculus. Exemplars considered include the fractional differential equations describing the dynamics of viscoelastic materials, turbulence, foraging, and phase transitions in complex social networks.

Bruce J. West

2014-10-09T23:59:59.000Z

486

Comparative Genomics Analysis and Phenotypic Characterization of Shewanella putrefaciens W3-18-1: Anaerobic Respiration, Bacterial Microcompartments, and Lateral Flagella  

SciTech Connect (OSTI)

Respiratory versatility and psychrophily are the hallmarks of Shewanella. The ability to utilize a wide range of electron acceptors for respiration is due to the large number of c-type cytochrome genes present in the genome of Shewanella strains. More recently the dissimilatory metal reduction of Shewanella species has been extensively and intensively studied for potential applications in the bioremediation of radioactive wastes of groundwater and subsurface environments. Multiple Shewanella genome sequences are now available in the public databases (Fredrickson et al., 2008). Most of the sequenced Shewanella strains were isolated from marine environments and this genus was believed to be of marine origin (Hau and Gralnick, 2007). However, the well-characterized model strain, S. oneidensis MR-1, was isolated from the freshwater lake sediment of Lake Oneida, New York (Myers and Nealson, 1988) and similar bacteria have also been isolated from other freshwater environments (Venkateswaran et al., 1999). Here we comparatively analyzed the genome sequence and physiological characteristics of S. putrefaciens W3-18-1 and S. oneidensis MR-1, isolated from the marine and freshwater lake sediments, respectively. The anaerobic respirations, carbon source utilization, and cell motility have been experimentally investigated. Large scale horizontal gene transfers have been revealed and the genetic divergence between these two strains was considered to be critical to the bacterial adaptation to specific habitats, freshwater or marine sediments.

Qiu, D.; Tu, Q.; He, Zhili; Zhou, Jizhong

2010-05-17T23:59:59.000Z

487

Effect of External Magnetic Fields on the Operation of RF Cavities  

SciTech Connect (OSTI)

Recent experiments have shown severe surface damage and a reduction of the maximum accelerating gradient for an rf cavity that is operating under external magnetic fields. This implies that serious problems may occur in lattices where rf cavities and external magnetic fields coexist, such as those of the proposed neutrino factory and muon collider. Although existing data suggest that this magnetic field dependent breakdown is associated with the emission of electrons from locally enhanced field regions on the cavity surface, the mechanism that drives this effect is not yet well understood. Here, we show that such field emitted electrons are accelerated by the cavity and focused by the magnetic field to the other side of the cavity where they heat its surface. We show that if the magnetic field is strong, significant surface deformation can occur that eventually could limit the accelerating gradient of the cavity. Results of our model are compared to the existing experimental data from an 805 MHz cavity. The geometry of the pillbox cavity in our case is more complicated, and the analysis depends on the electron energies, focused dimensions, and angle of impact, but damage may reasonably be expected with similar cyclical heating above 40 C. However, it is not yet known what the mechanism is for such surface damage to cause a cavity to breakdown. One possibility is that if electrons are focused on a location with a high surface gradient, then the local damage will generate new asperities with higher FN enhancement factors, thus initiating breakdown. While our preliminary analysis offers some quantification on the effects of the magnetic fields on the cavity's operation, other theoretical issues were not addressed. For instance, emission from secondary electrons was disregarded, the asperity was placed on axis, the magnetic field was assumed as uniform, the thermal-diffusion calculation ignored the shape of the rise time, and adopted an approximate calculation. On the theoretical level, it will be interesting to pursue additional simulations exploring these effects in detail. Experimentally, there is a clear need for more well-designed experiments to study, systematically, the effect of external fields on the cavity's operation.

Stratakis, D.; Berg, J.; Gallardo, J.C.; Palmer, R. B.

2010-12-01T23:59:59.000Z

488

E-Print Network 3.0 - ameliorates fractionated whole-brain Sample...  

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

fractionated whole-brain Search Powered by Explorit Topic List Advanced Search Sample search results for: ameliorates fractionated whole-brain Page: << < 1 2 3 4 5 > >> 1...

489

Pressurized water reactor fuel assembly subchannel void fraction measurement  

SciTech Connect (OSTI)

The void fraction measurement experiment of pressurized water reactor (PWR) fuel assemblies has been conducted since 1987 under the sponsorship of the Ministry of International Trade and Industry as a Japanese national project. Two types of test sections are used in this experiment. One is a 5 x 5 array rod bundle geometry, and the other is a single-channel geometry simulating one of the subchannels in the rod bundle. Wide gamma-ray beam scanners and narrow gamma-ray beam computed tomography scanners are used to measure the subchannel void fractions under various steady-state and transient conditions. The experimental data are expected to be used to develop a void fraction prediction model relevant to PWR fuel assemblies and also to verify or improve the subchannel analysis method. The first series of experiments was conducted in 1992, and a preliminary evaluation of the data has been performed. The preliminary results of these experiments are described.

Akiyama, Yoshiei [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan). Nuclear Fuel and Core Engineering Dept.; Hori, Keiichi [Mitsubishi Heavy Industries, Ltd., Hyougo (Japan); Miyazaki, Keiji [Osaka Univ. (Japan). Faculty of Engineering; Mishima, Kaichiro [Kyoto Univ., Osaka (Japan). Research Reactor Inst.; Sugiyama, Shigekazu [Nuclear Power Engineering Corp., Tokyo (Japan). Nuclear Fuel Dept.

1995-12-01T23:59:59.000Z

490

THE PAIR FRACTION OF MASSIVE GALAXIES AT 0 {<=} z {<=} 3  

SciTech Connect (OSTI)

Using a mass-selected (M{sub *} {>=} 10{sup 11} M{sub Sun }) sample of 198 galaxies at 0 {<=} z {<=} 3.0 with Hubble Space Telescope/NICMOS H{sub 160}-band images from the COSMOS survey, we find evidence for the evolution of the pair fraction above z {approx} 2, an epoch in which massive galaxies are believed to undergo significant structural and mass evolution. We observe that the pair fraction of massive galaxies is 0.15 {+-} 0.08 at 1.7 {<=}z {<=} 3.0, where galaxy pairs are defined as massive galaxies having a companion of flux ratio from 1:1 to 1:4 within a projected separation of 30 kpc. This is slightly lower but still consistent with the pair fraction measured previously in other studies, and the merger fraction predicted in halo-occupation modeling. The redshift evolution of the pair fraction is described by a power law F(z) = (0.07 {+-} 0.04) Multiplication-Sign (1 + z){sup 0.6{+-}0.5}. The merger rate is consistent with no redshift evolution; however it is difficult to constrain due to the limited sample size and the high uncertainties in the merging timescale. Based on the merger rate calculation, we estimate that a massive galaxy undergoes on average 1.1 {+-} 0.5 major mergers from z = 3 to 0. The observed merger fraction is sufficient to explain the number density evolution of massive galaxies, but insufficient to explain the size evolution. This is a hint that mechanism(s) other than major merging may be required to increase the sizes of the massive, compact quiescent galaxies from z {approx} 2 to 0.

Man, Allison W. S.; Toft, Sune; Zirm, Andrew W. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen (Denmark); Wuyts, Stijn [Max-Planck-Institut fuer Extraterrestrische Physik, Garching bei Muenchen (Germany); Van der Wel, Arjen, E-mail: allison@dark-cosmology.dk, E-mail: sune@dark-cosmology.dk, E-mail: azirm@dark-cosmology.dk, E-mail: swuyts@mpe.mpg.de, E-mail: vdwel@mpia.de [Max-Planck-Institut fuer Astronomie, Heidelberg (Germany)

2012-01-10T23:59:59.000Z

491

Recommended plutonium release fractions from postulated fires. Final report  

SciTech Connect (OSTI)

This report was written at the request of EG&G Rocky Flats, Inc. in support of joint emergency planning for the Rocky Flats Plant (RFP) by EG&G and the State of Colorado. The intent of the report is to provide the State of Colorado with an independent assessment of any respirable plutonium releases that might occur in the event of a severe fire at the plant. Fire releases of plutonium are of interest because they have been used by EG&G to determine the RFP emergency planning zones. These zones are based on the maximum credible accident (MCA) described in the RFP Final Environmental Impact Statement (FEIS) of 1980, that MCA is assumed to be a large airplane crashing into a RFP plutonium building.The objective of this report was first, to perform a worldwide literature review of relevant release experiments from 1960 to the present and to summarize those findings, and second, to provide recommendations for application of the experimental data to fire release analyses at Rocky Flats. The latter step requires translation between experimental and expected RFP accident parameters, or ``scaling.`` The parameters of particular concern are: quantities of material, environmental parameters such as the intensity of a fire, and the physico-chemical forms of the plutonium. The latter include plutonium metal, bulk plutonium oxide powder, combustible and noncombustible wastes contaminated with plutonium oxide powder, and residues from plutonium extraction processes.

Kogan, V.; Schumacher, P.M.

1993-12-01T23:59:59.000Z

492

Fluorescent spectra of chromatographic fractions of crude oils  

E-Print Network [OSTI]

Number 4 exhibits the j400 Ao peak. Again all Fig. 7 0 Fluorescent Spectra of n-heptane Fraction, Cut No. 2 ()) 0 fE 30 ( 3) / (lI I I I I (&) )/ I 000 travelength in Ao significant intensity ranges from 3400 A to 4600 A... as $ Transnlssion Cyclohexane Fraction 7'ave Length& Ao Relative Fluorescent Intensity ude o 3000 3100 3200 3300 3400 3500 3600 3F' jwo 4100 4200 4300 4400 4500 4600 QOO 4900 5000 5200 5400 56OO 5'800 6000 65oo 7000 Oe0 Oeo O. e 2 ' 4...

Dixon, William Samuel

2012-06-07T23:59:59.000Z

493

Separation of carbon nanotubes into chirally enriched fractions  

DOE Patents [OSTI]

A mixture of single-walled carbon nanotubes ("SWNTs") is separated into fractions of enriched chirality by preparing an aqueous suspension of a mixture of SWNTs and a surfactant, injecting a portion of the suspension on a column of separation medium having a density gradient, and centrifuging the column. In some embodiments, salt is added prior to centrifugation. In other embodiments, the centrifugation is performed at a temperature below room temperature. Fractions separate as colored bands in the column. The diameter of the separated SWNTs decreases with increasing density along the gradient of the column. The colored bands can be withdrawn separately from the column.

Doorn, Stephen K. (Los Alamos, NM); Niyogi, Sandip (Los Alamos, NM)

2012-04-10T23:59:59.000Z

494

FMC·RF'2a U.S. DEPARTlVIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER  

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

FMC·RF'2a FMC·RF'2a U.S. DEPARTlVIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER NEPA DETERlVIINATION RECIPIENT:Nevada State Office of Energy STATE: NV PROJECT Renewable Energy and Energy Efficiency Revolving Loan Program - Enigma Energy TITLE: Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number CID Number DE-FOA-OOOOOS2 DE-EE-0000084 GFO-0000084-012 EE84 Based on my review of the information concerning the proposed action, as NEPA Compliance Officer (authorized under DOE Order 451.1A), I have made the following determination: CX, EA, EIS APPENDIX AND NUMBER: Description: 85.1 Actions to conserve energy, demonstrate potential energy conservation , and promote energy-efficiency that do not increase the indoor concentrations of potentially harmful substances

495

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

SciTech Connect (OSTI)

Conceptual design of a bright electron injector for the 1 GeV high gradient test experiment. envisaged by the LLNL-SLAC-LBL collaboration on the Relativistic Klystron is presented. The design utilizes a high-brightness laser-driven RF photocathode electron gun, similar to the pioneering LANL early studies in concept (different parametrically however), together with achromatic magnetic bunching and transport systems and diagnostics. The design is performed with attention to possible use in an FEL as well. A simple but realistic analytic model including longitudinal and transverse space-charge and RF effects and extensive computer simulation form the basis of the parametric choice for the source. These parameters are used as guides for the design of the pico-second laser system and magnetic bunching section.

Chattopadhyay, S.; Chen, Y.J.; Hopkins, D.; Kim, K.J.; Kung, A.; Miller, R.; Sessler, a.; Young, T.

1988-09-01T23:59:59.000Z

496

Projected performance of rf-linac-driven free-electron lasers in the VUV and soft x-ray regions  

SciTech Connect (OSTI)

A multidisciplinary team of Los Alamos scientists, supported by the US Department of Energy, has been developing the requisite technologies to extend free-electron laser (FEL) operation from infrared and visible wavelengths into the extreme-ultraviolet below 100 nm using rf-linear accelerator technology. The goal is to establish an XUV Free-Electron Laser User Facility, the next-generation light source that will make available to researchers optical power more than one-million times greater than provided by synchroton light sources. Based primarily on a series of FEL oscillators driven by a single, rf-linac, the Los Alamos facility is designed to generate broadly tunable, picosecond-pulse, coherent radiation spanning the soft x-ray through the ultraviolet to the visible spectral ranges from 1 nm to 400 nm. The FEL facility design is discussed and performance predicted. 3 figs., 5 tabs.

Newnam, B.E.

1987-12-01T23:59:59.000Z

497

Adaptive {delta}f Monte Carlo Method for Simulation of RF-heating and Transport in Fusion Plasmas  

SciTech Connect (OSTI)

Essential for modeling heating and transport of fusion plasma is determining the distribution function of the plasma species. Characteristic for RF-heating is creation of particle distributions with a high energy tail. In the high energy region the deviation from a Maxwellian distribution is large while in the low energy region the distribution is close to a Maxwellian due to the velocity dependency of the collision frequency. Because of geometry and orbit topology Monte Carlo methods are frequently used. To avoid simulating the thermal part, {delta}f methods are beneficial. Here we present a new {delta}f Monte Carlo method with an adaptive scheme for reducing the total variance and sources, suitable for calculating the distribution function for RF-heating.

Hoeoek, J.; Hellsten, T. [Fusion Plasma Physics, School of Electrical Engineering, Royal Institute of Technology (KTH), SE-100 44, Stockholm, Association VR-Euratom (Sweden)

2009-11-26T23:59:59.000Z

498

Measurement of electron densities by a microwave cavity method in 13.56-MHz RF plasmas of Ar, CF4, C2F6, and CHF3  

Science Journals Connector (OSTI)

Electron densit ies have been determined /or RF plasmas that were generated within a microwave resonant cavity by measuring the difference of the resonance frequencies with and without plasma. Since that metho...

M. Haverlag; G. M. W. Kroesen; T. H. J. Bisschops…

1991-09-01T23:59:59.000Z

499

An Investigation of the Properties of Silicon Nitride (SiNx) Thin Films Prepared by RF Sputtering for Application in Solar Cell Technology  

Science Journals Connector (OSTI)

Silicon nitride films deposited on glass and multicrystalline silicon by RF sputtering with power between 100–350W. The target was hot pressed Si3N4 ceramic. The morphology and optical properties of films are inv...

Negin Manavizadeh; Alireza Khodayari…

2009-01-01T23:59:59.000Z

500

Subject: Biomedical Workforce Sustainability and Diversity Recommendations As part of our SUNY RF initiatives to grow research through recruitment of outstanding  

E-Print Network [OSTI]

Subject: Biomedical Workforce Sustainability and Diversity Recommendations As part of our SUNY RF Plans to Implement Biomedical Workforce Sustainability and Diversity Recommendations On December 6 recent ACD working group reports, the Biomedical Research Workforce Working Group Report

Linsley, Braddock K.