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1

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

SciTech Connect

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

2

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

3

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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.

4

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

Science Conference Proceedings (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

5

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

6

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

7

rf  

NLE Websites -- All DOE Office Websites (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

8

Teaching cell respiration  

NLE Websites -- All DOE Office Websites (Extended Search)

I am tearing my hair out trying to teach the subject of Cell Respiration and photosynthesis to students that are in some cases on a basic skills level of understanding. How...

9

RF transformer  

DOE Patents (OSTI)

There is provided an improved RF transformer having a single-turn secondary of cylindrical shape and a coiled encapsulated primary contained within the secondary. The coil is tapered so that the narrowest separation between the primary and the secondary is at one end of the coil. The encapsulated primary is removable from the secondary so that a variety of different capacity primaries can be utilized with one secondary.

Smith, James L. (Naperville, IL); Helenberg, Harold W. (Calumet City, IL); Kilsdonk, Dennis J. (Joliet, IL)

1979-01-01T23:59:59.000Z

10

rf_shield.PDF  

NLE Websites -- All DOE Office Websites (Extended Search)

April 2001 Interaction Region RF Shield Issues G. Stupakov and T.O. Raubenheimer Stanford Linear Accelerator Center Stanford, California 102300 Interaction Region RF Shield...

11

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

12

Rf feedback free electron laser  

DOE Patents (OSTI)

A free electron laser system and electron beam system for a free electron laser are provided 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, C.A.; Swenson, D.A.; Boyd, T.J. Jr.

1979-11-02T23:59:59.000Z

13

Radiolysis with RF Photoinjectors  

NLE Websites -- All DOE Office Websites (Extended Search)

Radiolysis with RF Photoinjectors: Supercritical Xenon Chemistry James F. Wishart in "Femtosecond Beam Science" Uesaka, M., Ed.; Imperial College Press, London, in press. (ISBN...

14

ORNL DAAC, global soil respiration rates  

NLE Websites -- All DOE Office Websites (Extended Search)

W. Raich and W. H. Schlesinger, the newly released data set contains soil respiration rates from sites in terrestrial and wetland ecosystems as reported in scientific literature...

15

Phase stable rf transport system  

DOE Patents (OSTI)

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

Curtin, M.T.; Natter, E.F.; Denney, P.M.

1991-02-19T23:59:59.000Z

16

Phase stable RF transport system  

DOE Patents (OSTI)

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

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

1992-01-01T23:59:59.000Z

17

Commercial SNF Accident Release Fractions  

Science Conference Proceedings (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

18

ISG8-RF Sources  

NLE Websites -- All DOE Office Websites (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

THE RELATION OF PHOTOSYNTHESIS TO RESPIRATION  

E-Print Network (OSTI)

eng-@ The Relation of Photosynthesis t o Respiration J.W.y independent paths i n photosynthesis am3 l i g h t ~ e s pup vphotosynthatesfl, 3 . Photosynthesis proceeds a t a

Weigl, J.W.; Warrington, P.M.; Calvin, M.

1950-01-01T23:59:59.000Z

20

Rf2a and rf2b transcription factors  

DOE Patents (OSTI)

A method of activating the rice tungro bacilliform virus (RTBV) promoter in vivo is disclosed. The RTBV promoter is activated by exposure to at least one protein selected from the group consisting of Rf2a and Rf2b.

Beachy, Roger N. (St. Louis, MO); Petruccelli, Silvana (La Plata, AR); Dai, Shunhong (St. Louis, MO)

2007-10-02T23:59:59.000Z

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.


21

Rf heating of mirrors  

SciTech Connect

A brief overview is presented of potential uses for rf heating of plasmas in mirror devices. While some discussion relating to past experiments is given, the main emphasis is devoted to a review of potential experiments in presently existing devices, and devices under construction or planning. Some predictions are made for plasmas in mirror reactors.

Porkolab, M.

1980-04-09T23:59:59.000Z

22

Eccentric rf deflecting structure  

SciTech Connect

For superconducting rf separators, assembled by electron beam welding techniques, two types of mode stabilizers are discussed: the elliptical structure, and a new design called the eccentric structure''. For an operating pi /2 or pi mode in the lower pass band, it is shown that the various parameters of the eccentric structure can be adjusted to provide the required frequency spacing between the operating mode and the upper dispersion curve. (auth)

Aggus, J.R.; Giordano, S.; Halama, H.J.

1973-12-13T23:59:59.000Z

23

The Relation of Quantum Requirement in Photosynthesis to Respiration  

E-Print Network (OSTI)

QUANTUM REQUIREMENT IN PHOTOSYNTHESIS TO RESPIRATION J a m eQUANTUM REQUIREMENT IN PHOTOSYNTHESIS Contents I n t r oducQUANTUM REQUIREMENT IN PHOTOSYNTHESIS TO RESPIRATION J a m e

Bassham, James A.; Shibata, Kazuo; Calvin, M.

1955-01-01T23:59:59.000Z

24

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

25

NSLS-II RF SYSTEMS  

Science Conference Proceedings (OSTI)

The NSLS-II is a new third generation light source being constructed at Brookhaven Lab. The storage ring is optimized for low emittance by use of damping wigglers to reduce the emittance to below 1 nm-rad. The RF systems are designed to provide stable beam through tight RF phase and amplitude stability requirements.

Rose, J.; Gash, W.; Holub, B.; Kawashima, Y.; Ma, H.; Towne, N.; Yeddulla, M.

2011-03-28T23:59:59.000Z

26

MSTC - Microsystems Science, Technology, and Components - RF...  

NLE Websites -- All DOE Office Websites (Extended Search)

capability for the unique demands of National Security. Communications RF MEMS Passive wireless sensorsRFIDsTags RF system minaturization For additional information or...

27

Spectroscopy of {sup 257}Rf.  

Science Conference Proceedings (OSTI)

The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti,n){sup 257}Rf. Reaction products were separated and identified by mass. Delayed spectroscopy of {sup 257}Rf 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{sup +}[620] configuration in {sup 253}No is proposed. The energy of this 1/2{sup +} 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 {sup 257}Rf, with a half-life of 160{sub -31}{sup +42} {micro}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{sub -1.3}{sup +2.4} s, followed by decay, was also observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf. Fission of {sup 257}Rf was unambiguously detected, with a branching ratio of b{sub Rf}{sup SF} = 0.02 {+-} 0.01.

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

2009-06-01T23:59:59.000Z

28

Spectroscopy of {sup 257}Rf  

Science Conference Proceedings (OSTI)

The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti,n){sup 257}Rf. Reaction products were separated and identified by mass. Delayed spectroscopy of {sup 257}Rf and its decay products was performed. A partial decay scheme with configuration assignments is proposed based on {alpha} hindrance factors. The excitation energy of the 1/2{sup +}[620] configuration in {sup 253}No is proposed. The energy of this 1/2{sup +} 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 {sup 257}Rf, with a half-life of 160{sub -31}{sup +42} {mu}s, was discovered by detecting internal conversion electrons followed by {alpha} 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{sub -1.3}{sup +2.4} s, followed by {alpha} decay, was also observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf. Fission of {sup 257}Rf was unambiguously detected, with a branching ratio of b{sub Rf}{sup SF}=0.02{+-}0.01.

Qian, J.; Heinz, A.; Winkler, R. [WNSL, Yale University, New Haven, Connecticut 06511 (United States); Khoo, T. L.; Janssens, R. V. F.; Peterson, D.; Seweryniak, D.; Ahmad, I.; Back, B. B.; Carpenter, M. P.; Greene, J. P.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Robinson, A.; Savard, G.; Scott, R.; Vondrasek, R.; Wang, X. [Argonne National Laboratory, Illinois 60439 (United States)] (and others)

2009-06-15T23:59:59.000Z

29

Booster Subharmonic RF Capture Design  

NLE Websites -- All DOE Office Websites (Extended Search)

require a < (1 40 ns) 25 MHz subharmonic frequency. Due to the difficulty of building high-voltage low-frequency rf cavities, this requirement can be relaxed so that at least...

30

Pushing the Limits of RF Superconductivity Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Presentations Workshop Proceedings Suggested Reading Material on RF Superconductivity Workshop Dinner Accommodations Ground Transportation Access to...

31

RF & Microwave Systems Group The RF & Microwave Systems  

E-Print Network (OSTI)

for Technology Transfer. Tagging, Tracking, and Locating Systems TTL technologies are on the verge and development (R&D) geared toward supplying robust communications for extreme environments; global tagging, tracking, and locating (TTL) systems; and RF- and microwave- based measurement and processing systems

32

Y-12 Respirator Flow Cycle Time Reduction Project  

SciTech Connect

In mid-July 2000, a Cycle Time Reduction (CTR) project was initiated by senior management to improve the flow and overall efficiency of the respirator distribution process at Y-12. A cross-functional team was formed to evaluate the current process and to propose necessary changes for improvement. Specifically, the team was challenged to make improvements that would eliminate production work stoppages due to the unavailability of respirators in Y-12 Stores. Prior to the team initiation, plant back orders for a specific model respirator were averaging above 600 and have been as high as 750+. The Cycle Time Reduction team segmented the respirator flow into detailed steps, with the focus and emphasis primarily being on the movement of dirty respirators out of work areas, transportation to Oak Ridge National Laboratory (ORNL) Laundry, and return back to Y-12 Stores inventory. The team selected a popular model respirator, size large, to track improvements. Despite a 30 percent increase in respirator usage for the same period of time in the previous year, the team has reduced the back orders by 89% with a steady trend downward. Summary of accomplishments: A 47 percent reduction in the average cycle time for dirty respirators to be laundered and stocked for reuse at the Y-12 Complex; A 73 percent reduction in the average cycle time for dirty respirators to be laundered and stocked for reuse specifically for major users: Enriched Uranium Operations (EUO) and Facilities Maintenance Organization (FMO); Development of a performance measure for tracking back orders; An 89 percent reduction in the number of laundered respirators on back order; Implementation of a tracking method to account for respirator loss; Achievement of an annual cost savings/avoidance of $800K with a one-time cost of $20K; Implementation of a routine pick-up schedule for EUO (major user of respirators); Elimination of activities no longer determined to be needed; Elimination of routine complaint calls to Stores requesting respirators; and Recommendation of improvements at the supplier (ORNL Laundry and Quality groups).

Hawk, C.T.; Rogers, P.E.

2000-12-01T23:59:59.000Z

33

Simulation of synchrotron motion with rf noise  

Science Conference Proceedings (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

34

MSTC - Microsystems Science, Technology, and Components - RF...  

NLE Websites -- All DOE Office Websites (Extended Search)

band RF input and supplies N identical outputs (N4 or 8). SiGe, GaAs, GaN RFICs. Passive RF detectors - Pyroelectric microdetectors that produce a DC output proportional to...

35

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

36

Modulation instability in RF MEMS devices  

Science Conference Proceedings (OSTI)

Modulation instability generated by mechanical frequencies in RF MEMS switches is predicted and its potential contribution to the RF signal degradation is discussed. In particular, evaluations have been performed for double clamped configurations in ... Keywords: Modulation instability, Nonlinear Schrodinger equation, Power handling, RF MEMS

Romolo Marcelli; Giancarlo Bartolucci; Giorgio Angelis; Andrea Lucibello; Emanuela Proietti

2012-04-01T23:59:59.000Z

37

Follow-up Review of Implementation Verification Reviews at the...  

NLE Websites -- All DOE Office Websites (Extended Search)

Potential Inadequacy in the Safety Analysis RF Respirable Fraction RI-AC Radionuclide Inventory-Administrative Control SAC Specific Administrative Control SRNL Savannah River...

38

Low jitter RF distribution system  

SciTech Connect

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

39

Rf System for the NLCTA  

Science Conference Proceedings (OSTI)

This paper describes an X-Band RF system for the Next Linear Collider Test Accelerator. The RF system consists of a 90 MeV injector and a 540 MeV linac. The main components of the injector are two low-Q single-cavity prebunchers and two 0.9-m-long detuned accelerator sections. The linac system consists of six 1.8-m-long detuned and damped detuned accelerator sections powered in pairs. The rf power generation, compression, delivery, distribution and measurement systems consist of klystrons, SLEDII energy compression systems, rectangular waveguides, magic-T's, and directional couplers. The phase and amplitude for each prebuncher is adjusted via a magic-T type phase shifter/attenuator. Correct phasing between the two 0.9 m accelerator sections is obtained by properly aligning the sections and adjusting two squeeze type phase shifters. Bunch phase and bunch length can be monitored with special microwave cavities and measurement systems. The design, fabrication, microwave measurement, calibration, and operation of the sub-systems and their components are briefly presented.

Wang, J.W.; /SLAC; Adolphsen, C.; Eichner, J.; Fuller, R.W.; Gold, S.L.; Hanna, S.M.; Hoag, H.A.; Holmes, S.G.; Koontz, R.F.; Lavine, Theodore L.; Loewen, R.J.; Miller, R.H.; Nantista, C.D.; Pope, R.; Rifkin, J.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, Z.; Yeremian, A.; /SLAC

2011-08-26T23:59:59.000Z

40

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

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

Overview of the RF Systems for LCLS  

SciTech Connect

The Linac Coherent Light Source (LCLS) at SLAC, when it becomes operational in 2009, will provide its user community with an X-ray source many orders of magnitude brighter than anything available in the world at that time [1]. The electron beam acceleration will be provided by existing and new RF systems capable of maintaining the amplitude and phase stability of each bunch to extremely tight tolerances. RF feedback control of the various RF systems will be fundamental in ensuring the beam arrives at the LCLS undulator at precisely the required energy and peak current phase. This paper details the requirements for RF stability for the various LCLS RF systems and also highlights proposals for how these injector and Linac RF systems can meet these tight constraints.

McIntosh, P.; Akre, R.; Boyce, R.; Emma, P.; Hill, A.; Rago, C.; /SLAC

2005-06-15T23:59:59.000Z

42

Overview of the RF Systems for LCLS  

E-Print Network (OSTI)

The Linac Coherent Light Source (LCLS) at SLAC, when it becomes operational in 2009, will provide its user community with an X-ray source many orders of magnitude brighter than anything available in the world at that time. The electron beam acceleration will be provided by existing and new RF systems capable of maintaining the amplitude and phase stability of each bunch to extremely tight tolerances. RF feedback control of the various RF systems will be fundamental in ensuring the beam arrives at the LCLS undulator at precisely the required energy and phase. This paper details the requirements for RF stability for the various LCLS RF systems and also highlights proposals for how these injector and Linac RF systems can meet these constraints.

McIntosh, Peter; Boyce, Richard; Emma, Paul; Hill, Alan; Rago, Carl

2005-01-01T23:59:59.000Z

43

Decay Study of {sup 257}Rf  

Science Conference Proceedings (OSTI)

The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti, n){sup 257}Rf. Reaction products were separated by the Argonne Fragment Mass Analyzer. Radioactive decay and spontaneous fission of {sup 257}Rf and its decay products were investigated. An isomeric state in {sup 257}Rf, with a half-life of 160{sub -31}{sup 42} {mu}S, was discovered by detecting internal conversion electrons followed by alpha decays. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal-conversion electrons which were succeeded by alpha decay, with a half-life of 4.1{sub -1.3}{sup +2.4} s, was observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf, or from another isomer in {sup 257}Rf.

Qian, J.; Heinz, A.; Winkler, R. [Yale University, New Haven, CT 06511 (United States); Janssens, R. V. F.; Khoo, T. L.; Seweryniak, D.; Peterson, D.; Back, B. B.; Carpenter, M. P.; Greene, J. P.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Pardo, R. C.; Robinson, A.; Scott, R.; Vondrasek, R.; Wang, X.; Zhu, S. [Argonne National Laboratory, Argonne, IL 60439 (United States)] (and others)

2009-03-04T23:59:59.000Z

44

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

45

A Survey of the Urban RF Environment  

Science Conference Proceedings (OSTI)

The prevalence of sources of radio-frequency (RF) electromagnetic fields is expanding at a rapid pace.  As new wireless technologies are deployed (e.g., smart meters), questions are often raised as to what extent people are exposed to their RF emissions, and what if any effects on health and safety the RF could possibly cause. To obtain a frame of reference for the contributions of new sources to our environment, this study was designed to quantify the levels of RF fields that already exist in ...

2012-12-31T23:59:59.000Z

46

Characteristics of multiantenna rf ion source  

Science Conference Proceedings (OSTI)

We have developed a new multiantenna rf ion source for neutral beam injection and studied the effects of different antennas connected in parallel

T. Shoji; Y. Oka; NBI Group

2006-01-01T23:59:59.000Z

47

Passive RF Components - Microsystems Science, Technology, and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Passive RF Components Microsystems Home Custom Microsystems Solutions Microsystems R&D Services Capabilities and Technologies Facilities Trusted Microsystems General Info About Us...

48

Recent Studies of RF Breakdown Physics in Normal Conducting Cavities  

SciTech Connect

The operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The behavior of the rf breakdown depends on multiple parameters, including the input rf power, rf circuit, cavity shape and material. Here we discuss recent experimental data and theoretical studies of rf breakdown physics.

Dolgashev, Valery; /SLAC

2012-06-11T23:59:59.000Z

49

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

50

Sunpentown: ENERGY STAR Referral (RF-330SS) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ENERGY STAR Referral (RF-330SS) Sunpentown: ENERGY STAR Referral (RF-330SS) May 10, 2013 DOE referred the matter of Sunpentown-brand refrigerator, model RF-330SS, manufactured by...

51

Samsung: ENERGY STAR Referral (RF26VAB) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Samsung: ENERGY STAR Referral (RF26VAB) Samsung: ENERGY STAR Referral (RF26VAB) March 16, 2010 DOE referred the matter of Samsung refrigerator-freezer model RF26VAB to the U.S....

52

R&D ERL: Low level RF  

SciTech Connect

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

53

Linear Gain for the Microbunching Instability in an RF Compressor  

E-Print Network (OSTI)

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

Venturini, M.

2010-01-01T23:59:59.000Z

54

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

Science Conference Proceedings (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

55

Matching network for RF plasma source  

DOE Patents (OSTI)

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

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

2007-11-20T23:59:59.000Z

56

Review of the APS SR RF systems.  

DOE Green Energy (OSTI)

The Advanced Photon Source (APS) is a 7-GeV full energy storage ring (SR) for generating synchrotron radiation with an injector. The storage ring cavities consist of four groups of four single cells powered by up to four 1-MW klystrons for up to 300-mA operation. A review of the operation of the rf system as well as rf-related beam dynamics is presented. This review includes rf power distribution, low-level feedback, control law, beam loading, beam instabilities, higher-order modes, and beam-induced multipactoring.

Song, J.J.; Cours, A.; Grelick, A.; Harkay, K.; Horan, D.; Kang, Y.W.; Kustom, R.L.; Nassiri, A.; Pile, G.; Smith, T.L.

1998-03-31T23:59:59.000Z

57

Degreasing and cleaning superconducting RF Niobium cavities  

Science Conference Proceedings (OSTI)

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

Rauchmiller, Michael; Kellett, Ron; /Fermilab

2011-09-01T23:59:59.000Z

58

RF Micro Devices | Open Energy Information  

Open Energy Info (EERE)

National Center for Photovoltaics Partnership Year 2009 LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now RF Micro Devices is a company located in...

59

SLAC Linac RF Performance for LCLS *  

E-Print Network (OSTI)

The Linac Coherent Light Source (LCLS) project at SLAC uses a dense 15 GeV electron beam passing through a long undulator to generate extremely bright x-rays at 1.5 angstroms. The project requires electron bunches with a nominal peak current of 3.5kA and bunch lengths of 0.020mm (70fs). The bunch compression techniques used to achieve the high brightness impose challenging tolerances on the accelerator RF phase and amplitude. The results of measurements on the existing SLAC linac RF phase and amplitude stability are summarised and improvements needed to meet the LCLS tolerances are discussed. 1 LCLS RF REQUIREMENTS LCLS requires the SLAC linac to perform with tolerances on RF phase and amplitude stability which are beyond all previous requirements. The LCLS is divided into four linacs L0, L1, L2, and L3 [1]. The phase and amplitude tolerances for the four linacs operated at S-

unknown authors

2000-01-01T23:59:59.000Z

60

Deeply scaled CMOS for RF power applications  

E-Print Network (OSTI)

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

Scholvin, Jörg, 1976-

2006-01-01T23:59:59.000Z

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.


61

Ozone removal capability of a welding fume respirator containing activated charcoal  

SciTech Connect

Development of air purifying respirators for protection against ozone has been slowed by concerns about oxidation of charcoal and other available sorbents. The suitability of a charcoal sorbent for low concentrations of ozone was evaluated as a part of the development of a half-mask air purifying respirator designed for welding fumes and ozone. Testing of the respirator confirmed that charcoal can be a suitable sorbent for low levels of ozone. Where the respirator is properly selected, fit tested, and worn, respirator use against welding fumes and ozone at concentrations not exceeding 10 times the permissible exposure limit had been recommended.

Johnston, A.R.; Dyrud, J.F.; Shih, Y.T. (Occupational Health and Environmental Safety Division, St. Paul, MN (USA))

1989-09-01T23:59:59.000Z

62

Vortex formation during rf heating of plasma  

SciTech Connect

Experiments on a test plasma show that the linear theory of waveguide coupling to slow plasma waves begins to break down if the rf power flux exceeds approx. 30 W/cm/sup 2/. Probe measurements reveal that within 30 ..mu..s an undulation appears in the surface plasma near the mouth of the twin waveguide. This surface readjustment is part of a vortex, or off-center convective cell, driven by asymmetric rf heating of the plasma column.

Motley, R.W.

1980-05-01T23:59:59.000Z

63

High Power RF Sources for Accelerators  

SciTech Connect

This presentation describes RF sources developed and under development at Calabazas Creek Research, Inc. for driving high power accelerators and colliders. The RF sources range from L-Band to W-Band and power levels from 10s of kilowatts CW to 200 MW pulsed. The configurations include standard klystrons, multiple beam klystrons, sheet beam devices, and gyroklystrons. The basic parameters are presented with a basic description of operation and applications.

Ives, Lawrence; Read, Michael; Neilson, Jeff; Borchard, Philipp; Mizuhara, Max [Calabazas Creek Research, Inc., 690 Port Drive, San Mateo, CA 94404 (United States); Lawson, Wesley [Insitute for Research in Applied Physics, University of Maryland, College Park, MD 20742 (United States)

2006-11-27T23:59:59.000Z

64

Simulations of Ion Migration in the LCLS RF Gun and Injector  

SciTech Connect

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

65

Prospects for Advanced RF Theory and Modeling  

SciTech Connect

This paper represents an attempt to express in print the contents of a rather philosophical review talk. The charge for the talk was not to summarize the present status of the field and what we can do, but to assess what we will need to do in the future and where the gaps are in fulfilling these needs. The objective was to be complete, covering all aspects of theory and modeling in all frequency regimes, although in the end the talk mainly focussed on the ion cyclotron range of frequencies (ICRF). In choosing which areas to develop, it is important to keep in mind who the customers for RF modeling are likely to be and what sorts of tasks they will need for RF to do. This occupies the first part of the paper. Then we examine each of the elements of a complete RF theory and try to identify the kinds of advances needed.

Batchelor, D.B.

1999-04-12T23:59:59.000Z

66

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

Science Conference Proceedings (OSTI)

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

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

2012-12-21T23:59:59.000Z

67

Respirator studies for the AEC Division of Operational Safety. Progress report, January 1--June 30, 1973  

SciTech Connect

The LASL Respirator Research and Development Section, Industrial Hygiene Group, performed studies and conducted training for the Division of Operational Safety (DOS) during the second half of FY 1973. The major work involved development and initiation of a training course for AEC contractors and AEC personnel; writing a Respirator Manual for use by the AEC and their contractors; providing consulting services for the DOS and contractors; man testing several respirators; and holding a three-day Respirator Symposium jointly sponsored by the DOS, the Directorate of Regulatory Standards, and LASL. (auth)

Hyatt, E.C.; Held, B.J.; Bevis, D.J.; Moore, T.O.

1973-12-01T23:59:59.000Z

68

Tubular RF cage field confinement cavity - Energy Innovation ...  

An RF cavity is provided with a plurality of tubes that are formed into a tubular cage in a predefined shape to define the RF cavity. A selected number of tubes and a ...

69

Klystron "efficiency loop" for the ALS storage ring RF system  

E-Print Network (OSTI)

EFFICIENCY LOOP” FOR THE ALS STORAGE RING RF SYSTEM* S.at the Advanced Light Source (ALS) in order to decrease thethe cavities. 1 INTRODUCTION ALS Storage Ring RF system is

Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

2002-01-01T23:59:59.000Z

70

Transient beam loading in the ALS harmonic RF system  

E-Print Network (OSTI)

TRANSIENT BEAM LOADING IN THE ALS HARMONIC RF SYSTEM * J.as the Advanced Light Source (ALS), with moderately low beamharmonic RF system on the ALS storage ring consisting of 5

2000-01-01T23:59:59.000Z

71

Stored carbon partly fuels fine-root respiration but is not used for production of new fine roots  

SciTech Connect

The relative use of new photosynthate compared to stored C for the production and maintenance of fine roots, and the rate of C turnover in heterogeneous fine-root populations, are poorly understood. We followed the relaxation of a 13C tracer in fine roots in a Liquidambar styraciflua plantation at the conclusion of a free-air CO2 enrichment experiment. Goals included quantifying the relative fractions of new photosynthate versus stored C used in root growth and root respiration, as well as the turnover rate of fine-root C fixed during [CO2] fumigation. New fine-root growth was largely from recent photosynthate, while nearly one-quarter of respired C was from a storage pool. Changes in the isotopic composition of the fine-root population over two full growing seasons indicated heterogeneous C pools; less than 10% of root C had a residence time < 3 months, while a majority of root C had a residence time > 2 years. Compared to a 1-pool model, a 2-pool model for C turnover in fine roots (with 5 and 0.37 yr-1 turnover times) doubles the fine-root contribution to forest NPP (9-13%) and supports the 50% root-to-soil transfer rate often used in models.

Lynch, Douglas J [ORNL; Matamala-Paradeda, Roser [ORNL; Iversen, Colleen M [ORNL; Norby, Richard J [ORNL; Gonzalez-Meler, Miguel A [ORNL

2013-01-01T23:59:59.000Z

72

Eccentric superconducting RF cavity separator structure  

DOE Patents (OSTI)

Accelerator apparatus having an eccentric-shaped, iris-loaded deflecting cavity for an rf separator for a high energy high momentum, charged particle accelerator beam. In one embodiment, the deflector is superconducting, and the apparatus of this invention provides simplified machining and electron beam welding techniques. Model tests have shown that the electrical characteristics provide the desired mode splitting without adverse effects.

Aggus, John R. (Shoreham, NY); Giordano, Salvatore T. (Port Jefferson, NY); Halama, Henry J. (Shoreham, NY)

1976-01-01T23:59:59.000Z

73

RF Breakdown of Metallic Surfaces in Hydrogen  

DOE Green Energy (OSTI)

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

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

2009-05-01T23:59:59.000Z

74

RF Design of the LCLS Gun  

Science Conference Proceedings (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

75

Cw rf operation of the FMIT RFQ  

SciTech Connect

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

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

1985-01-01T23:59:59.000Z

76

BeginPackage "rfPack`" Modified 28 Jul 1999  

E-Print Network (OSTI)

voltage vRF, stable phase angle £ in units of 2¥ , and wavelength ¤ ." bucketHF::usage ¡ "bucketHF ¢ ,h compaction ¢ , an RF system with harmonic number h, peak voltage vRF, and stable phase angle £ in units of 2 with harmonic number h, peak voltage vRF, and stable phase angle £ in units of 2¥ , for particles of energy E

Keil, Eberhard

77

RUGGED CERAMIC WINDOW FOR RF APPLICATIONS  

Science Conference Proceedings (OSTI)

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

MIKE NEUBAUER

2012-11-01T23:59:59.000Z

78

Novel methods for respirable dust removal. Final report  

SciTech Connect

Two novel devices with potential for controlling emissions of dust particles in the respirable size range (0.3 to 3 microns) are the electrostatically enhanced cyclone (or electrocyclone) and acoustic agglomeration. The electrocyclone combines electrostatic, inertial forces and larger unit size compared to conventional cyclones to achieve improved performance. The acoustic agglomerator uses an oscillating acoustic flow field to cause particle collision and agglomeration. The resulting large particles are then more readily separable by conventional methods. The application of these novel methods to respirable dust control in pressurized fluidized-bed combustion and conventional pulverized coal combustion for electric power generation is explored in this study. In a PFBC power plant, dust particles entrained in the combustion gases must be removed at high temperature and pressure in order to protect a gas turbine from erosion. A key technical issue in this application is whether the hot gas cleanup equipment can satisfy the NSPS, or whether supplementary stack gas cleanup, such as a baghouse, is required downstream of the gas turbine. The potential of both the electrocyclone and the acoustic agglomerator for achieving NSPS ahead of the gas turbine has been assessed. In conventional PC power plants, particulate cleanup is normally accomplished with electrostatic precipitators. However, plants burning low sulfur western coals have experienced difficulty achieving adequate particulate emissions control with electrostatic precipitators, due to the high resistivity of the coal ash. For these applications the electrocyclone or an acoustic agglomerator coupled with either an electrocyclone or more conventional removal technique, might prove attractive. The principal conclusions drawn from the work performed and the recommendations based on the results are detailed. (LTN)

1980-09-01T23:59:59.000Z

79

Superconducting RF systems for eRHIC  

Science Conference Proceedings (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

80

Symmetric continued fractions  

SciTech Connect

Explicit formulae for continued fractions with symmetric patterns in their partial quotients are constructed in the field of formal power series. Similar to the work of Cohn in 1996, which generalized the so-called folding lemma to {kappa}-fold symmetry, the notion of {kappa}-duplicating symmetric continued fractions is investigated using a modification of the 1995 technique due to Clemens, Merrill and Roeder.

Panprasitwech, Oranit [Department of Mathematics, Faculty of Science, King Mongkut' s University of Technology Thonburi, Bangkok 10140 (Thailand); Laohakosol, Vichian [Department of Mathematics, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Chaichana, Tuangrat [Department of Mathematics, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

2010-11-11T23:59:59.000Z

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.


81

RF Gun Photocathode Research at SLAC  

Science Conference Proceedings (OSTI)

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

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

2012-05-16T23:59:59.000Z

82

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

83

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

E-Print Network (OSTI)

The main purpose of this dissertation was to address key issues in the design and analysis of RF/microwave filters for wireless applications. Since RF/microwave filters are one of the bulkiest parts of communication systems, their miniaturization is one of the most important technological challenges for the development of compact transceivers. In this work, novel miniaturization techniques were investigated for single-band, dual-band, ultra-wideband and tunable bandpass filters. In single-band filters, the use of cross-shaped fractals in half-mode substrate-integrated-waveguide bandpass filters resulted in a 37 percent size reduction. A compact bandpass filter that occupies an area of 0.315 mm2 is implemented in 90-nm CMOS technology for 20 GHz applications. For dual-band filters, using half-mode substrate-integrated-waveguides resulted in a filter that is six times smaller than its full-mode counterpart. For ultra-wideband filters, using slow-wave capacitively-loaded coplanar-waveguides resulted in a filter with improved stopband performance and frequency notch, while being 25 percent smaller in size. A major part of this work also dealt with the concept of 'hybrid' RF MEMS tunable filters where packaged, off-the-shelf RF MEMS switches were used to implement high-performance tunable filters using substrate-integrated-waveguide technology. These 'hybrid' filters are very easily fabricated compared to current state-of-the-art RF MEMS tunable filters because they do not require a clean-room facility. Both the full-mode and half-mode substrate-integrated waveguide tunable filters reported in this work have the best Q-factors (93 - 132 and 75 - 140, respectively) compared to any 'hybrid' RF MEMS tunable filter reported in current literature. Also, the half-mode substrate-integrated waveguide tunable filter is 2.5 times smaller than its full-mode counterpart while having similar performance. This dissertation also presented detailed analytical and simulation-based studies of nonlinear noise phenomena induced by Brownian motion in all-pole RF MEMS tunable filters. Two independent mathematical methods are proposed to calculate phase noise in RF MEMS tunable filters: (1) pole-perturbation approach, and (2) admittance-approach. These methods are compared to each other and to harmonic balance noise simulations using the CAD-model of the RF MEMS switch. To account for the switch nonlinearity in the mathematical methods, a nonlinear nodal analysis technique for tunable filters is also presented. In summary, it is shown that output signal-to-noise ratio degradation due to Brownian motion is maximum for low fractional bandwidth, high order and high quality factor RF MEMS tunable filters. Finally, a self-sustained microwave platform to detect the dielectric constant of organic liquids is presented in this dissertation. The main idea is to use a voltage- controlled negative-resistance oscillator whose frequency of oscillation varies according to the organic liquid under test. To make the system self-sustained, the oscillator is embedded in a frequency synthesizer system, which is then digitally interfaced to a computer for calculation of dielectric constant. Such a system has potential uses in a variety of applications in medicine, agriculture and pharmaceuticals.

Sekar, Vikram

2011-08-01T23:59:59.000Z

84

Initial RF measurements of the CW normal-conducting RF injector  

Science Conference Proceedings (OSTI)

The LANL 2.5-cell, normal-conducting radio-frequency (NCRF) injector has been fabricated. We present initial results of low-power RF measurements (cavity Q, cavity field map, coupling beta, etc.) of the NCRF injector. The measured cavity Q and relative fields are found to be in good agreement with the design calculations and earlier measurements of Glidcop properties. However, the coupling beta of the ridge-loaded waveguides is found to be significantly higher than the design point. The impact of these low-power measurement results on the planned high-power RF and electron beam tests will be discussed.

Krawcyk, Frank L [Los Alamos National Laboratory; Moody, Nathan A [Los Alamos National Laboratory; Martinez, Felix A [Los Alamos National Laboratory; Nguyen, Dinh C [Los Alamos National Laboratory; Bolme, Gerald [Los Alamos National Laboratory; Young, Karen [Los Alamos National Laboratory; Toung, Lloyd [AES

2008-01-01T23:59:59.000Z

85

RF heating and current drive on NSTX with high  

SciTech Connect

NSTX is a small aspect ratio tokamak (R = 0.85 m, a = 0.65 m). The High Harmonic Fast Wave (HHFW) system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ~3 MW for 100-400 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with significant fractions (0.4) of bootstrap current. Differences in the loop voltage are observed depending on whether the array is phased to drive current in the co- or counter-current directions. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial rf power deposition and driven current profiles have been calculated with ray tracing and kinetic full-wave codes and compared with measurements.

Ryan, Philip Michael [ORNL; Peng, Yueng Kay Martin [ORNL

2003-01-01T23:59:59.000Z

86

Realization and modeling of rf superconducting quantum interference device metamaterials  

E-Print Network (OSTI)

We have prepared meta-atoms based on radio frequency superconducting quantum interference devices (RF SQUIDs) and examined their tunability with dc magnetic field, rf current, and temperature. RF SQUIDs are superconducting split ring resonators in which the usual capacitance is supplemented with a Josephson junction, which introduces strong nonlinearity in the rf properties. We find excellent agreement between the data and a model which regards the Josephson junction as the resistively and capacitively-shunted junction. A magnetic field tunability of 80 THz/Gauss at 12 GHz is observed, a total tunability of 56$%$ is achieved, and a unique electromagnetically-induced transparency feature at intermediate excitation powers is demonstrated for the first time. An RF SQUID metamaterial is shown to have qualitatively the same behavior as a single RF SQUID with regards to DC flux and temperature tuning.

M. Trepanier; Daimeng Zhang; Oleg Mukhanov; Steven M. Anlage

2013-08-06T23:59:59.000Z

87

CLIC RF High Power Production Testing Program  

SciTech Connect

The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production ({approx} 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented.

Syratchev, I.; Riddone, G.; /CERN; Tantawi, S.G.; /SLAC

2011-11-02T23:59:59.000Z

88

Accelerator and rf system development for NLC  

Science Conference Proceedings (OSTI)

An experimental station for an X-band Next Linear Collider has been constructed at SLAC. This station consists of a klystron and modulator, a low-loss waveguide system for rf power distribution, a SLED II pulse-compression and peak-power multiplication system, acceleration sections and beam-line components (gun, prebuncher, preaccelerator, focussing elements and spectrometer). An extensive program of experiments to evaluate the performance of all components is underway. The station is described in detail in this paper, and results to date are presented.

Vlieks, A.E.; Callin, R.; Deruyter, H. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)] [and others

1993-04-01T23:59:59.000Z

89

Available Technologies: High Efficiency Spiral RF-Induction ...  

The spiral antennas efficient use of source geometry also ... Neutron and high energy gamma ... A typical RF-induction plasma generator with a ...

90

Influence of Substrate Temperature and RF Power on the Formation ...  

Science Conference Proceedings (OSTI)

Presentation Title, Influence of Substrate Temperature and RF Power on the Formation of ZnO Nanorods for Solar Driven Hydrogen Production. Author(s) ...

91

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

92

High power RF test of an 805 MHz RF cavity for a muon cooling channel  

SciTech Connect

We present recent high power RF test results on an 805 MHz cavity for a muon cooling experiment at Lab G in Fermilab. In order to achieve high accelerating gradient for large transverse emittance muon beams, the cavity design has adopted a pillbox like shape with 16 cm diameter beam iris covered by thin Be windows, which are demountable to allow for RF tests of different windows. The cavity body is made from copper with stiff stainless steel rings brazed to the cavity body for window attachments. View ports and RF probes are available for visual inspections of the surface of windows and cavity and measurement of the field gradient. Maximum of three thermo-couples can be attached to the windows for monitoring the temperature gradient on the windows caused by RF heating. The cavity was measured to have Q{sub 0} of about 15,000 with copper windows and coupling constant of 1.3 before final assembling. A 12 MW peak power klystron is available at Lab G in Fermilab for the high power test. The cavity and coupler designs were performed using the MAFIA code in the frequency and the time domain. Numerical simulation results and cold test measurements on the cavity and coupler will be presented for comparisons.

Li, Derun; Corlett, J.; MacGill, R.; Rimmer, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian, Z.; Wu, V.; Summers, D.; Norem, J.

2002-05-30T23:59:59.000Z

93

Global net primary production and heterotrophic respiration for 1987  

Science Conference Proceedings (OSTI)

An ecosystem process model, BIOME-BGC, was parameterized and used to simulate the actual net primary production and heterotrophic respiration using daily climatic data, land cover type, leaf area index gridded to 1{degree} latitude by 1{degree} longitude grid cells for the year 1987. Global net primary production was 52 Pg C. These estimates were validated directly by two different methods. First, the grid cells were aggregated and used as inputs to a 3D atmospheric transport model, to compare CO{sub 2} station data with predictions. We simulated the intra-annual variation of atmospheric CO{sub 2} well for the northern hemisphere, but not for the southern hemisphere. Second, we calculated the net {sup 13}C uptake of vegetation, which is a function of water use efficiency. The {sup 13}C/{sup 12}C ratios agreed with measured data, indicating a strong limitation of global primary processes by the hydrologic cycle, especially precipitation. These are different from other global carbon models as we can simulate the year-to-year variation of climate, including El Nino, on the global carbon cycle.

Hunt, R.E. Jr.; Piper, S.C.; Nemani, R. [Univ. of Montana, Missoula, MT (United States)]|[Scripps Institute of Oceanography, La Jolla, CA (United States)] [and others

1995-06-01T23:59:59.000Z

94

Low-power/low-voltage RF microsystems for wireless sensors networks  

Science Conference Proceedings (OSTI)

This paper presents radio-frequency (RF) microsystems (MSTs) composed by low-power devices for use in wireless sensors networks (WSNs). The RF CMOS transceiver is the main electronic system and its power consumption is a critical issue. Two RF CMOS transceivers ... Keywords: RF CMOS transceiver, RF microsystems, Wireless sensors networks

J. P. Carmo; J. H. Correia

2009-12-01T23:59:59.000Z

95

Interannual Variability in Global Soil Respiration on a 0.5 Degree...  

NLE Websites -- All DOE Office Websites (Extended Search)

D. Bhagawati. 2003. Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994). NDP-081. Carbon Dioxide Information Analysis Center, U.S....

96

Interannual Variability in Global Soil Respiration on a 0.5 Degree...  

NLE Websites -- All DOE Office Websites (Extended Search)

Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) (NDP-081) DOI: 10.3334CDIAClue.ndp081 PDF PDF Contributors James W. Raich 1,...

97

Interannual Variability in Global Soil Respiration on a 0.5 Degree...  

NLE Websites -- All DOE Office Websites (Extended Search)

D. Bhagawati. 2003. Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994). ORNLCDIAC-144, NDP-081. Available on-line http:...

98

A Global Database of Soil Respiration Data, Version 2.0  

NLE Websites -- All DOE Office Websites (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

99

Recent advances in RF power generation  

SciTech Connect

This paper is a review of the progress and methods used in RF generation for particle accelerators. The frequencies of interest are from a few megahertz to 100 GHz, and the powers are for super linear collider applications, but in this case the pulses are short, generally below 1 {mu}s. The very high-power, short-pulse generators are only lightly reviewed here, and for more details the reader should follow the specialized references. Different RF generators excel over various parts of the frequency spectrum. Below 100 MHz solid-state devices and gridded tubes prevail, while the region between 400 MHz and 3 GHz, the cyclotron-resonant devices predominate, and above 250 GHz, Free-Electron Lasers and ubitrons are the most powerful generators. The emphasis for this review is on microwave generation at frequencies below 20 GHz, so the cyclotron-resonant devices are only partially reviewed, while the progress on free-electron laser and ubitrons is not reviewed in this paper. 39 refs., 4 figs.

Tallerico, P.J.

1990-01-01T23:59:59.000Z

100

Extremely high frequency RF effects on electronics.  

SciTech Connect

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

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

Fermilab Tevatron high level rf accelerating systems  

SciTech Connect

Eight tuned rf cavities have been installed and operated in the F0 straight section of the Tevatron. Their mechanical placement along the beam line enables them to be operated for colliding beams as two independent groups of four cavities, group 1-4 accelerating antiprotons and group 5-8 accelerating protons. The only difference is that the spacing between cavities 4 and 5 was increased to stay clear of the F0 colliding point. The cavities can easily be rephased by switching cables in a low-level distribution system (fan-out) so that the full accelerating capability of all eight cavities can be used during fixed target operations. Likewise, the cables from capacitive probes on each cavity gap can be switched to proper lengths and summed in a fan-back system to give an rf signal representing the amplitude and phase as ''seen by the beam,'' separately for protons and antiprotons. Such signals have been used to phase lock the Tevatron to the Main Ring for synchronous transfer.

Kerns, Q.; Kerns, C.; Miller, H.; Tawser, S.; Reid, J.; Webber, R.; Wildman, D.

1985-06-01T23:59:59.000Z

102

Clean fractionation of biomass  

Science Conference Proceedings (OSTI)

The US Department of Energy (DOE) Alternative Feedstocks (AF) program is forging new links between the agricultural community and the chemicals industry through support of research and development (R & D) that uses `green` feedstocks to produce chemicals. The program promotes cost-effective industrial use of renewable biomass as feedstocks to manufacture high-volume chemical building blocks. Industrial commercialization of such processes would stimulate the agricultural sector by increasing the demand of agricultural and forestry commodities. New alternatives for American industry may lie in the nation`s forests and fields. The AF program is conducting ongoing research on a clean fractionation process. This project is designed to convert biomass into materials that can be used for chemical processes and products. Clean fractionation separates a single feedstock into individual components cellulose, hemicellulose, and lignin.

Not Available

1995-01-01T23:59:59.000Z

103

Booster Synchrotron RF System Upgrade for SPEAR3  

Science Conference Proceedings (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

104

Self-homodyne RF-optical microdisk receiver  

E-Print Network (OSTI)

modulation with optical transfer function (Po VRF 2 ) Self-homodyne RF-photonic receiver f ip Nonlinear and nonlinear modulation Transmittedoptical power t Wavelength t t Linear (Po VRF) Nonlinear (Po VRF 2) VRF ),,,,,( , 0 2 0 2 2 tPQGf dV Pd N EinoV VRF RF == = Microdisk optical mixer (laser= res) GV : voltage gain Q

Levi, Anthony F. J.

105

ITO Thin Films by RF Sputtering for Ethanol Sensing  

Science Conference Proceedings (OSTI)

The sensor for detection of ethanol vapours using RF sputter deposited ITO thin film on glass and Si substrates is reported. The principle of operation is the change of resistance of ITO film on exposure to ethanol vapours. The films were annealed at ... Keywords: Indium Tin Oxide, RF sputtering, ethanol sensor

Sudhir Chandra; H. J. Pandya; A. L. Vyas

2010-07-01T23:59:59.000Z

106

RF cavity using liquid dielectric for tuning and cooling  

SciTech Connect

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

107

A high-power L-band RF window  

E-Print Network (OSTI)

June. 2001. [3] "700 MHz Window R&D at LBNL", R. Rimmer et.Testing of PEP-II RF Cavity Windows", M. Neubauer et. al. ,A HIGH-POWER L-BAND RF WINDOW* R.A. Rimmer † , G. Koehler,

2001-01-01T23:59:59.000Z

108

RF-MEMS capacitive switches with high reliability  

DOE Patents (OSTI)

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

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

2013-09-03T23:59:59.000Z

109

RF Power Degradation of GaN High Electron Mobility Transistors  

E-Print Network (OSTI)

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

Joh, Jungwoo

110

Progress on the RF Coupling Coil Module Design for the MICE Channel  

E-Print Network (OSTI)

Spallation Neutron Source (SNS) type ceramic RF windows arecouplers together with the SNS-type ceramic RF window. Ahigh power tested now at the SNS RF test lab. Cavity length

2005-01-01T23:59:59.000Z

111

Proposal for high pressure RF cavity test in the MTA  

DOE Green Energy (OSTI)

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

Yonehara, K.; /Fermilab

2010-09-01T23:59:59.000Z

112

Cold Test Measurements on the GTF Prototype RF Gun  

Science Conference Proceedings (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

113

Automated Hydroforming of Seamless Superconducting RF Cavity  

SciTech Connect

We are studying the possibility of automated hydroforming process for seamless superconducting RF cavities. Preliminary hydroforming tests of three-cell cavities from seamless tubes made of C1020 copper have been performed. The key point of an automated forming is to monitor and strictly control some parameters such as operation time, internal pressure and material displacements. Especially, it is necessary for our studies to be able to control axial and radial deformation independently. We plan to perform the forming in two stages to increase the reliability of successful forming. In the first stage hydroforming by using intermediate constraint dies, three-cell cavities were successfully formed in less than 1 minute. In parallel, we did elongation tests on cavity-quality niobium and confirmed that it is possible to achieve an elongation of >64% in 2 stages that is required for our forming of 1.3 GHz cavities.

Nagata, Tomohiko [ULVAC, Inc.; Shinozawa, Seiichi [ULVAC, Inc.; Abe, Noriyuki [ULVAC, Inc.; Nagakubo, Junki [ULVAC, Inc.; Murakami, Hirohiko [ULVAC, Inc.; Tajima, Tsuyoshi [Los Alamos National Laboratory; Inoue, Hitoshi [High Energy Accelerator Research Organization, KEK; Yamanaka, Masashi [High Energy Accelerator Research Organization, KEK; Ueno, Kenji [High Energy Accelerator Research Organization, KEK

2012-07-31T23:59:59.000Z

114

Fast thermometry for superconducting rf cavity testing  

SciTech Connect

Fast readout of strategically placed low heat capacity thermometry can provide valuable information of Superconducting RF (SRF) cavity performance. Such a system has proven very effective for the development and testing of new cavity designs. Recently, several resistance temperature detectors (RTDs) were installed in key regions of interest on a new 9 cell 3.9 GHz SRF cavity with integrated HOM design at FNAL. A data acquisition system was developed to read out these sensors with enough time and temperature resolution to measure temperature changes on the cavity due to heat generated from multipacting or quenching within power pulses. The design and performance of the fast thermometry system will be discussed along with results from tests of the 9 cell 3.9GHz SRF cavity.

Orris, Darryl; Bellantoni, Leo; Carcagno, Ruben H.; Edwards, Helen; Harms, Elvin Robert; Khabiboulline, Timergali N.; Kotelnikov, Sergey; Makulski, Andrzej; Nehring, Roger; Pischalnikov, Yuriy; /Fermilab

2007-06-01T23:59:59.000Z

115

Estimating nocturnal ecosystem respiration from the vertical turbulent flux and change in storage of CO2  

Science Conference Proceedings (OSTI)

Micrometeorological measurements of nighttime ecosystem respiration can be systematically biased when stable atmospheric conditions lead to drainage flows associated with decoupling of air flow above and within plant canopies. The associated horizontal and vertical advective fluxes cannot be measured using instrumentation on the single towers typically used at micrometeorological sites. A common approach to minimize bias is to use a threshold in friction velocity, u*, to exclude periods when advection is assumed to be important, but this is problematic in situations when in-canopy flows are decoupled from the flow above. Using data from 25 flux stations in a wide variety of forest ecosystems globally, we examine the generality of a novel approach to estimating nocturnal respiration developed by van Gorsel et al. (van Gorsel, E., Leuning, R., Cleugh, H.A., Keith, H., Suni, T., 2007. Nocturnal carbon efflux: reconciliation of eddy covariance and chamber measurements using an alternative to the u*-threshold filtering technique. Tellus 59B, 397 403, Tellus, 59B, 307-403). The approach is based on the assumption that advection is small relative to the vertical turbulent flux (FC) and change in storage (FS) of CO2 in the few hours after sundown. The sum of FC and FS reach a maximum during this period which is used to derive a temperature response function for ecosystem respiration. Measured hourly soil temperatures are then used with this function to estimate respiration RRmax. The new approach yielded excellent agreement with (1) independent measurements using respiration chambers, (2) with estimates using ecosystem light-response curves of Fc + Fs extrapolated to zero light, RLRC, and (3) with a detailed process-based forest ecosystem model, Rcast. At most sites respiration rates estimated using the u*-filter, Rust, were smaller than RRmax and RLRC. Agreement of our approach with independent measurements indicates that RRmax provides an excellent estimate of nighttime ecosystem respiration

Gu, Lianhong [ORNL; Van Gorsel, Eva [CSIRO Marine and Atmospheric Research; Leuning, Ray [CSIRO Marine and Atmospheric Research; Delpierre, Nicolas [Universite Paris XI, Orsay, France; Black, Andy [University of British Columbia, Vancouver; Chen, Baozhang [University of British Columbia, Vancouver; Munger, J. William [Harvard University; Wofsy, Steve [Harvard University; Aubinet, M. [Faculte Universitaire des Sciences Agronomiques de Gembloux

2009-11-01T23:59:59.000Z

116

Using Fractional Numbers of . . .  

E-Print Network (OSTI)

One of the design parameters in closed queueing networks is Np, the number of customers of class p. It has been assumed that Np must be an integer. However, integer choices will usually not achieve the target throughput for each class simultaneously. We use Mean Value Analysis with the Schweitzer-Bard approximation and nonlinear programming to determine the value of Np needed to achieve the production targets exactly, although the values of Np may be fractional. We interpret these values to represent the average number of customers of each class in the network. We implement a control rule to achieve these averages and verify our approach through simulation.

Rajan Suri; Rahul Shinde; Mary Vernon

2005-01-01T23:59:59.000Z

117

Fractional channel multichannel analyzer  

DOE Patents (OSTI)

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

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

1994-08-23T23:59:59.000Z

118

Plasma rotation and rf heating in DIII-D  

SciTech Connect

In a variety of discharge conditions on DIII-D it is observed that rf electron heating reduces the toroidal rotation speed and core ion temperature. The rf heating can be with either fast wave or electron cyclotron heating and this effect is insensitive to the details of the launched toroidal wavenumber spectrum. To date all target discharges have rotation first established with co-directed neutral beam injection. A possible cause is enhanced ion momentum and thermal diffusivity due to electron heating effectively creating greater anomalous viscosity. Another is that a counter directed toroidal force is applied to the bulk plasma via rf driven radial current.

deGrassie, J.S.; Baker, D.R.; Burrell, K.H. [General Atomics, San Diego, CA (United States)] [and others

1999-05-01T23:59:59.000Z

119

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

SciTech Connect

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

Guo, Jiquan; /SLAC

2009-03-20T23:59:59.000Z

120

The Path of Carbon in Photosynthesis VII Respiration andPhotosynthesis  

SciTech Connect

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

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

Handbook for Gas Filled RF Cavity Aficionados'  

DOE Green Energy (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

122

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":""}]}

123

Rf system for the NSLS coherent infrared radiation source  

Science Conference Proceedings (OSTI)

The existing NSLS X-ray Lithography Source (XLS Phase I) is being considered for a coherent synchrotron radiation source. The existing 211 MHz warm cavity will be replaced with a 5-cell 2856 MHz superconducting RF cavity, driven by a series of 2 kW klystrons. The RF system will provide a total V{sub RF} of 1.5 MV to produce {sigma}{sub L} = 0.3 mm electron bunches at an energy of 150 MeV. Superconducting technology significantly reduces the required space and power needed to achieve the higher voltage. It is the purpose of this paper to describe the superconducting RF system and cavity, power requirements, and cavity design parameters such as input coupling, Quality Factor, and Higher Order Modes.

Broome, W.; Biscardi, R.; Keane, J.; Mortazavi, P.; Thomas, M.; Wang, J.M.

1995-05-01T23:59:59.000Z

124

Efficiency enhancement techniques for RF and millimeter wave power amplifiers  

E-Print Network (OSTI)

Power amplifiers are the circuit blocks in wireless transceivers that require the largest power budget because of their relatively low efficiencies. RF designers cannot depend solely on the development better semiconductor ...

Ogunnika, Olumuyiwa Temitope, 1978-

2012-01-01T23:59:59.000Z

125

Channel engineering of SOI MOSFETs for RF applications  

E-Print Network (OSTI)

Channel engineering of SOI MOSFETs is explored by altering ion implantation without adding any new fabrication steps to the standard CMOS process. The effects of implantation on characteristics important for RF applications, ...

Keast, Craig L.

126

An improved RF cavity search for halo axions  

E-Print Network (OSTI)

The axion is a hypothetical elementary particle and cold dark matter candidate. In this RF cavity experiment, halo axions entering a resonant cavity immersed in a static magnetic field convert into microwave photons, with ...

Yu, D. B. (Daniel Byungyoon), 1976-

2004-01-01T23:59:59.000Z

127

High Frequency High Power RF Generation using a Relativistic...  

NLE Websites -- All DOE Office Websites (Extended Search)

FREQUENCY HIGH POWER RF GENERATION USING A RELATIVISTIC ELECTRON BEAM C. Jing , S. Antipov, P. Schoessow, and A. Kanareykin, Euclid Techlabs LLC, Solon, OH-44139 J.G. Power, M....

128

Hom dampers for ALS storage ring RF cavities  

E-Print Network (OSTI)

of the HOM dampers on ALS rf cavities was an immediatesuccess. Now, the ALS storage ring can operate with the 312The cross-section of the ALS third harmonic cavity with two

2003-01-01T23:59:59.000Z

129

Electrodeless lighting RF power source development. Final report  

SciTech Connect

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

NONE

1996-08-30T23:59:59.000Z

130

ANALYZING SURFACE ROUGHNESS DEPENDENCE OF LINEAR RF LOSSES  

SciTech Connect

Topographic structure on Superconductivity Radio Frequency (SRF) surfaces can contribute additional cavity RF losses describable in terms of surface RF reflectivity and absorption indices of wave scattering theory. At isotropic homogeneous extent, Power Spectrum Density (PSD) of roughness is introduced and quantifies the random surface topographic structure. PSD obtained from different surface treatments of niobium, such Buffered Chemical Polishing (BCP), Electropolishing (EP), Nano-Mechanical Polishing (NMP) and Barrel Centrifugal Polishing (CBP) are compared. A perturbation model is utilized to calculate the additional rough surface RF losses based on PSD statistical analysis. This model will not consider that superconductor becomes normal conducting at fields higher than transition field. One can calculate the RF power dissipation ratio between rough surface and ideal smooth surface within this field range from linear loss mechanisms.

Reece, Charles E. [JLAB; Kelley, Michael J. [JLAB, W& M College; Xu, Chen [JLAB, W& M College

2012-09-01T23:59:59.000Z

131

A Test and Diagnosis Methodology for RF Transceivers  

Science Conference Proceedings (OSTI)

This paper proposes an RF test and diagnosis methodology based on digital DFT structure and builtin DSP function of a SoC Chip. Constellation variation plots are proposed to identify the faulty component. Furthermore, linear interpolation is used to ...

Hung-kai Chen; Chauchin Su

2007-10-01T23:59:59.000Z

132

Test estructural i predictiu per a circuits RF CMOS.  

E-Print Network (OSTI)

??En aquesta tesi s'ha desenvolupat una tècnica de test que permet testar un LNA i un mesclador, situats en el capçal RF d'un receptor CMOS,… (more)

Suenaga Portugués, Kay

2008-01-01T23:59:59.000Z

133

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

134

Recent Progress of RF Cavity Study at Mucool Test Area  

DOE Green Energy (OSTI)

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

Yonehara, Katsuya; /Fermilab

2011-12-02T23:59:59.000Z

135

Micropower RF transponder with superregenerative receiver and RF receiver with sampling mixer  

DOE Patents (OSTI)

A micropower RF transponder employs a novel adaptation of the superregenerative receiver wherein the quench oscillator is external to the regenerative transistor. The quench oscillator applies an exponentially decaying waveform rather than the usual sinewave to achieve high sensitivity at microampere current levels. Further improvements include circuit simplifications for antenna coupling, extraction of the detected signal, and a low-voltage bias configuration that allows operation with less than a 1-volt rail voltage. The inventive transponder is expected to operate as long as the battery shelf life. 13 figs.

McEwan, T.E.

1997-05-13T23:59:59.000Z

136

Micropower RF transponder with superregenerative receiver and RF receiver with sampling mixer  

DOE Patents (OSTI)

A micropower RF transdponder employs a novel adaptation of the superregenerative receiver wherein the quench oscillator is external to the regenerative transistor. The quench oscillator applies an exponentially decaying waveform rather than the usual sinewave to achieve high sensitivity at microampere current levels. Further improvements include circuit simplifications for antenna coupling, extraction of the detected signal, and a low-voltage bias configuration that allows operation with less than a 1-volt rail voltage. The inventive transponder is expected to operate as long as the battery shelf life.

McEwan, Thomas E. (Livermore, CA)

1997-01-01T23:59:59.000Z

137

RF and Beam Diagnostic Instrumentation at the Advanced Photon Source (APS) Linear Accelerator (Linac)  

E-Print Network (OSTI)

RF and Beam Diagnostic Instrumentation at the Advanced Photon Source (APS) Linear Accelerator (Linac)

Grelick, A E; Arnold, N; White, M

1996-01-01T23:59:59.000Z

138

Rf power systems for the national synchrotron light source  

SciTech Connect

The booster synchrotron and the two storage rings at the NSLS are provided with rf power systems of 3 kW, 50 kW, and 500 kW nominal output power, all at 53 MHz. This power is supplied by grounded grid tetrode amplifiers designed for television broadcast service. These amplifiers and associated power supplies, control and interlock systems, rf controls, and computer interface are described.

Dickinson, T.; Rheaume, R.H.

1981-01-01T23:59:59.000Z

139

COMPARISON OF RF CAVITY TRANSPORT MODELS FOR BBU SIMULATIONS  

Science Conference Proceedings (OSTI)

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

Ilkyoung Shin,Byung Yunn,Todd Satogata,Shahid Ahmed

2011-03-01T23:59:59.000Z

140

The fractional symmetric rigid rotor  

E-Print Network (OSTI)

Based on the Riemann fractional derivative the Casimir operators and multipletts for the fractional extension of the rotation group SO(n) are calculated algebraically. The spectrum of the corresponding fractional symmetric rigid rotor is discussed. It is shown, that the rotational, vibrational and $\\gamma$-unstable limits of the standard geometric collective models are particular limits of this spectrum. A comparison with the ground state band spectra of nuclei shows an agreement with experimental data better than 2%. The derived results indicate, that the fractional symmetric rigid rotor is an appropriate tool for a description of low energy nuclear excitations.

Richard Herrmann

2006-10-24T23:59:59.000Z

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

Impacts of Shewanella oneidensis c-type cytochromes on aerobic and anaerobic respiration  

SciTech Connect

Shewanella are renowned for their ability to utilize a wide range of electron acceptors (EA) for respiration, which has been partially accredited to the presence of a large number of the c-type cytochromes. To investigate the involvement of c-type cytochrome proteins in aerobic and anaerobic respiration of Shewanella oneidensis Mr -1, 36 in-frame deletion mutants, among possible 41 predicted, c-type cytochrome genes were obtained. The potential involvement of each individual c-type cytochrome in the reduction of a variety of EAs was assessed individually as well as in competition experiments. While results on the wellstudied c-type cytochromes CymA(SO4591) and MtrC(SO1778) were consistent with previous findings, collective observations were very interesting: the responses of S. oneidensis Mr -1 to low and highly toxic metals appeared to be significantly different; CcoO, CcoP and PetC, proteins involved in aerobic respiration in various organisms, played critical roles in both aerobic and anaerobic respiration with highly toxic metals as EA. In addition, these studies also suggested that an uncharacterized c-type cytochrome (SO4047) may be important to both aerobiosis and anaerobiosis.

Gao, Haichun; Barua, Soumitra; Liang, Yili; Wu, Lianming; Dong, Yangyang; Reed, Samantha B.; Chen, Jingrong; Culley, David E.; Kennedy, David W.; Yang, Yunfeng; He, Zhili; Nealson, Kenneth H.; Fredrickson, Jim K.; Tiedje, James M.; Romine, Margaret F.; Zhou, Jizhong

2010-06-24T23:59:59.000Z

142

Effects of p-Cresol on photosynthetic and respiration rates of a filamentous green alga (spirogyra)  

Science Conference Proceedings (OSTI)

The effects of spilled phenols and cresols from coal gasification plants on the green alga SPIROYRA was investigated in experimental streams built by the US EPA near Monticello, Minnesota. P-Cresol at low concentrations inhibited photosynthesis and increased algal respiration rates. (JMT)

Stout, J. (Michigan State Univ., East Lansing); Kilham, S.S.

1983-01-01T23:59:59.000Z

143

RF-Plasma Source Commissioning in Indian Negative Ion Facility  

Science Conference Proceedings (OSTI)

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

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

2011-09-26T23:59:59.000Z

144

A Holographic Fractional Topological Insulator  

E-Print Network (OSTI)

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

Carlos Hoyos-Badajoz; Kristan Jensen; Andreas Karch

2010-07-19T23:59:59.000Z

145

Clean Fractionation: Technology Available for Licensing  

an eicient biomass pretreatment process—clean fractionation. Description . Clean fractionation is a process for upgrading biomass feedstocks for a

146

Microsoft PowerPoint - rf_5year_review  

NLE Websites -- All DOE Office Websites (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

147

A 12 GHz RF Power Source for the CLIC Study  

SciTech Connect

The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

2012-07-03T23:59:59.000Z

148

RF Power Upgrade for CEBAF at Jefferson Laboratory  

Science Conference Proceedings (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

149

rf improvements for Spallation Neutron Source H ion source  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering 38 mA H beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride AlN plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier. 2010 American Institute of Physics.

Kang, Yoon W [ORNL; Fuja, Raymond E [ORNL; Goulding, Richard Howell [ORNL; Hardek, Thomas W [ORNL; Lee, Sung-Woo [ORNL; McCarthy, Mike [ORNL; Piller, Chip [ORNL; Shin, Ki [ORNL; Stockli, Martin P [ORNL; Welton, Robert F [ORNL

2010-01-01T23:59:59.000Z

150

A computer program for HVDC converter station RF noise calculations  

SciTech Connect

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

151

Control of the LHC 400 MHz RF System (ACS)  

E-Print Network (OSTI)

The LHC ACS RF system is composed of 16 superconducting cavities, eight per ring. Each ring has two cryomodules, each containing four cavities. Each cavity is powered by a 300 kW klystron. The klystrons are grouped in fours, the klystrons in each group sharing a common 58 kV power converter and HV equipment bunker. The ACS RF control system is based on modern industrial programmable controllers (PLCs). A new fast interlock and alarm system with inbuilt diagnostics has been developed. Extensive use of the FIPIO Fieldbus drastically decreases the cabling complexity and brings improved signal quality, increased reliability and easier maintenance. Features of the implementation, such as system layout, communication and the high-level software interface are described. Operational facilities such as the automatic switch on procedure are described, as well as the necessary specialist tools and interfaces. A complete RF chain, including high voltage, cryomodule and klystron is presently being assembled in order to ch...

Arnaudon, L; Maesen, P; Prax, M

2004-01-01T23:59:59.000Z

152

Overview and status of RF systems for the SSC Linac  

SciTech Connect

The Superconducting Super Collider (SSC) Linear Accelerator (Linac) produces a 600-MeV, 35-{mu}s, H-beam at a 10-Hz repetition rate. The beam is accelerated by a series of RF cavities. These consist of a Radio Frequency Quadrupole (RFQ), two bunchers, and four Drift Tube Linac (DTL) tanks at 427.617 MHz, and two bunchers, nine side-coupled Linac modules, and an energy compressor at 1282.851 MHz. The RFQ amplifier and the low-frequency buncher cavity amplifiers use gridded tubes, while the other cavities use klystron amplifier systems. The RF control system consists of a reference line and cavity feedback and feedforward loops for each amplifier. The RF amplifier system for each of these accelerator cavities is described, and the current status of each system is presented.

Mynk, J.; Grippe, J.; Cutler, R.I.; Rodriguez, R.

1993-05-01T23:59:59.000Z

153

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

Science Conference Proceedings (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

154

Aspects of superconductivity and fractionalization  

E-Print Network (OSTI)

Since their discovery in mid 80's, a complete theory of high temperature superconductors is yet to take its final shape. Theory of fractionalization attempts to explain the phenomenon by assuming that the electron is split ...

Raut, Dinesh V

2005-01-01T23:59:59.000Z

155

Selection of respirator test panels representative of U.S. adult facial sizes  

SciTech Connect

As requested by the National Institute for Occupational Safety and Health (NIOSH), the Los Alamos Scientific Laboratory Respirator Research and Development Section, Industrial Hygiene Group, has prepared anthropometric specifications for subjects to test the fit of half-mask, quarter-mask, and full- facepiece respirators. A facial survey of 200 males was conducted, with results similar to those of a recent survey of some 4000 U. S. airmen. Subjects were selected on the basis of face length and face width to wear full-face masks in tests. For testing halfand quarter-masks, face length and lip length were used. Test panels containing 25 male-and-female subjects were used to represent a majority of the working population. A sequential sampling scheme was developed to reduce the amount of testing required to determine if a mask provides adequate protection for diffurent facial sizes. Examples of man test results are given. (auth)

Hack, A.; Hyatt, E.C.; Held, B.J.; Moore, T.O.; Richards, C.P.; McConville, J.T.

1973-12-01T23:59:59.000Z

156

Heterotrophic respiration in disturbed forests: A review with examples from North America  

Science Conference Proceedings (OSTI)

Heterotrophic respiration (RH), the oxidation of organic matter to carbon dioxide by free-living microorganisms, is one of three major processes releasing carbon to the atmosphere, the other two being autotrophic respiration (RA) and combustion. Over long times and large spatial extents these three fluxes roughly equal the amount of carbon being fixed by photosynthesis, at least in upland ecosystems (Frey and Smith 2005). Over short period of time or within small areas changes in the strength of these fluxes can determine when and where an ecosystem is a source or sink of carbon relative to the atmosphere (reference from Hurtt disturbance paper). Thus, the understanding of the biophysical factors that regulate the strength of these fluxes is a current topic of research.

Harmon, Mark; Bond-Lamberty, Benjamin; Tang, Jianwu; Vargas, Rodrigo

2011-05-17T23:59:59.000Z

157

Apparatus and method for collection and concentration of respirable particles into a small fluid volume  

DOE Patents (OSTI)

An apparatus and method for the collection of respirable particles and concentration of such particles into a small fluid volume. The apparatus captures and concentrates small (1-10 .mu.m) respirable particles into a sub-millileter volume of fluid. The method involves a two step operation, collection and concentration: wherein collection of particles is by a wetted surface having small vertical slits that act as capillary channels; and concentration is carried out by transfer of the collected particles to a small volume (sub-milliliter) container by centrifugal force whereby the particles are forced through the vertical slits and contact a non-wetted wall surface, and are deflected to the bottom where they are contained for analysis, such as a portable flow cytometer or a portable PCR DNA analysis system.

Simon, Jonathan N. (San Leandro, CA); Brown, Steve B. (Livermore, CA)

2002-01-01T23:59:59.000Z

158

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

E-Print Network (OSTI)

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

Venturini, M.

2010-01-01T23:59:59.000Z

159

Microbial metal reduction by members of the genus Shewanella: novel strategies for anaerobic respiration  

SciTech Connect

Metal-reducing members of the genus Shewanella are important components of the microbial community residing in redox-stratified freshwater and marine environments. Metal-reducing gram-negative bacteria such as Shewanella, however, are presented with a unique physiological challenge: they are required to respire anaerobically on terminal electron acceptors which are either highly insoluble (Fe(III)- and Mn(IV)-oxides) and reduced to soluble end-products or highly soluble (U(VI) and Tc(VII)) and reduced to insoluble end-products. To overcome physiological problems associated with metal solubility, metal-respiring Shewanella are postulated to employ a variety of novel respiratory strategies not found in other gram-negative bacteria which respire on soluble electron acceptors such as O2, NO3 and SO4. The following chapter highlights the latest findings on the molecular mechanism of Fe(III), U(VI) and Tc(VII) reduction by Shewanella, with particular emphasis on electron transport chain physiology.

Dichristina, Thomas; Bates, David J.; Burns, Justin L.; Dale, Jason R.; Payne, Amanda N.

2006-01-01T23:59:59.000Z

160

Dynamics of an electron in an rf gap  

Science Conference Proceedings (OSTI)

The purpose of this calculation is to understand the limitation on the energy transfer efficiency of an electron beam to the rf output cavity of a klystron or a lasertron. An output cavity with drift tubes is modeled in this calculation by a region of constant amplitude rf field with exponentially decreasing entrance and exit fringing fields. The exit velocity of an electron traversing such a gap is examined as a function of entrance phase for various values of the ratio of the peak rf cavity voltage to electron entrance voltage. Depending on this ratio, the dynamics of the electron motion can become quite complex. For a gap with fringe fields it is found that, even if the gap voltage and phase are optimized, the maximum energy that can be extracted from a short bunch is always significantly less than 100%. The case in which the electron is created with zero velocity in the gap, and subsequently leaves the gap having extracted energy from the rf field, is also treated. 4 refs., 10 figs.

Farkas, Z.D.; Wilson, P.B.

1989-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
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161

RF Cherenkov picosecond timing technique for high energy physics applications  

Science Conference Proceedings (OSTI)

The Cherenkov time-of-propagation (TOP) detector and Cherenkov time-of-flight (TOF) detector in a ?head-on? geometry based on the recently proposed time measuring technique with radio frequency (RF) phototube are considered. Results of the Monte Carlo simulations are presented.

Margaryan, Amur; Hashimoto, Osamu; Majewski, Stanislaw; Tang, Liguang

2008-09-01T23:59:59.000Z

162

The RF, Communications and Intelligent Systems (RFCIS) Group  

E-Print Network (OSTI)

Federal Laboratory Consortium for Technology Transfer. Tagging, Tracking, and Locating Systems TTL and development (R&D) geared toward supplying robust communications for extreme environments; global tagging, tracking, and locating (TTL) systems; and RF- and microwave-based measurement and processing systems

163

RF coupler for high-power CW FEL photoinjector  

SciTech Connect

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. The design presently under way is a 100-mA 2.5-cell {pi}-mode, 700-MHz, normal conducting demonstration CW RF photoinjector. This photoinjector will be capable of accelerating 3 nC per bunch with an emittance at the wiggler less than 10 mm-mrad. The paper presents results for the RF coupling from ridged wave guides to hte photoinjector RF cavity. The LEDA and SNS couplers inspired this 'dog-bone' design. Electromagnetic modeling of the coupler-cavity system has been performed using both 2-D and 3-D frequency-domain calculations, and a novel time-domain approach with MicroWave Studio. These simulations were used to adjust the coupling coefficient and calculate the power-loss distribution on the coupling slot. The cooling of this slot is a rather challenging thermal management project.

Kurennoy, S. (Sergey); Young, L. M. (Lloyd M.)

2003-01-01T23:59:59.000Z

164

Stochastic fluctuations of dust particle charge in RF discharges  

Science Conference Proceedings (OSTI)

In addition to RF oscillations, intrinsic stochastic fluctuations due to the discreteness of electrons and ions could be important to the charging of a dust particle in RF discharges. These fluctuations are studied in the present work for three cases [M. Bacharis et al., Plasma Sources Sci. Technol. 19, 025002 (2010)] relevant to RF discharges employing a recently proposed model [B. Shotorban, Phys. Rev. E 83, 066403 (2011)] valid for stochastic charging at nonstationary states. The cases are concerned with a time varying electron number density relevant to sheaths, a time varying electric field relevant to the bulk plasma, and a time-dependent bi-Maxwellian distribution of electrons in a low pressure discharge. Two dust particles with different sizes are individually studied in each case. The radius of one is ten times larger than the radius of the other. In all of the cases, for the larger dust particle, the root-mean-squre of charge stochastic fluctuations is about an order of magnitude smaller than the amplitude of RF charge oscillations, while for the smaller dust particle, they are comparable in magnitude.

Shotorban, B. [Department of Mechanical and Aerospace Engineering, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)

2012-05-15T23:59:59.000Z

165

Tubular Radio Frequency (RF) Cage Field Confinement Cavity (IN-05-107)  

Scientists at Argonne National Laboratory have created innovations in the design and fabrication of radio frequency (RF) cavities that improve ...

166

Computer-Controlled Scanning Electron Microscopy (CCSEM) Investigation of Respirable Quartz in Air Samples Collected During Power Plant Maintenance Activities  

Science Conference Proceedings (OSTI)

Reliable methods of determining the amount of respirable, crystalline silica (quartz) in coal fly ash (CFA) are clearly of interest in order to satisfy Occupational Safety and Health Administration (OSHA) regulations and to accurately assess the potential risks of workers with prolonged CFA exposure to certain respiratory diseases. Earlier EPRI-sponsored research focused on development of a new method for determining the amount of respirable quartz in bulk CFA samples using computer-controlled scanning e...

2008-12-08T23:59:59.000Z

167

Unified Fractional Kinetic Equation and a Fractional Diffusion Equation  

E-Print Network (OSTI)

In earlier papers Saxena et al. (2002, 2003) derived the solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which extended the work of Haubold and Mathai (2000). The object of the present paper is to investigate the solution of a unified form of fractional kinetic equation in which the free term contains any integrable function f(t), which provides the unification and extension of the results given earlier recently by Saxena et al. (2002, 2003). The solution has been developed in terms of the Wright function in a closed form by the method of Laplace transform. Further we derive a closed-form solution of a fractional diffusion equation. The asymptotic expansion of the derived solution with respect to the space variable is also discussed. The results obtained are in a form suitable for numerical computation.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2004-06-22T23:59:59.000Z

168

Design of RF Feed System for Standing-Wave Accelerator Structures  

Science Conference Proceedings (OSTI)

We are investigating a standing wave accelerator structure that uses a 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, J.; Tantawi, S.; Dolgashev, V.; /SLAC

2012-05-25T23:59:59.000Z

169

rf power system for thrust measurements of a helicon plasma source  

SciTech Connect

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

170

Free electron laser using Rf coupled accelerating and decelerating structures  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

171

National rf technology research and development program plan  

Science Conference Proceedings (OSTI)

This plan was prepared by the Oak Ridge National Laboratory at the request of the Office of Fusion Energy, Division of Development and Technology, to define the technology development needs and priorities. The US rf research and development community, with a wide representation from universities, laboratories and industries, participated in many discussions, meetings and in a three-day workshop in developing the needs and priorities definition. This very active and effective involvement of the rf leaders from all of these groups was an essential feature of the activity and results in the plan representing a broad consensus from the magnetic fusion energy development community. In addition, a number of scientists from Japan and Europe participated by providing data.

Not Available

1983-05-01T23:59:59.000Z

172

Design of RF systems for the RTD mission VASIMR  

SciTech Connect

The first flight test of the variable specific impulse magnetoplasma rocket (VASIMR) is tentatively scheduled for the Radiation and Technology Demonstration (RTD) in 2003. This mission to map the radiation environment out to several earth radii will employ both a Hall thruster and a VASIMR during its six months duration, beginning from low earth orbit. The mission will be powered by a solar array providing 12 kW of direct current electricity at 50 V. The VASIMR utilizes radiofrequency (RF) power both to generate a high-density plasma in a helicon source and to accelerate the plasma ions to high velocity by ion cyclotron resonance heating (ICRH). The VASIMR concept is being developed by the National Aeronautics and Space Administration (NASA) in collaboration with national laboratories and universities. Prototype plasma sources, RF amplifiers, and antennas are being developed in the experimental facilities of the Advanced Space Propulsion Laboratory (ASPL). (c) 1999 American Institute of Physics.

Baity, F. W. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Barber, G. C. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Carter, M. D. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Goulding, R. H. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Sparks, D. O. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Chang-Diaz, F. R. [Advanced Space Propulsion Laboratory, NASA, Johnson Space Center, Houston, Texas 77059 (United States); McCaskill, G. E. [Advanced Space Propulsion Laboratory, NASA, Johnson Space Center, Houston, Texas 77059 (United States); Squire, J. P. [Advanced Space Propulsion Laboratory, NASA, Johnson Space Center, Houston, Texas 77059 (United States)

1999-09-20T23:59:59.000Z

173

Design of RF Systems for the RTD Mission VASIMR  

SciTech Connect

The first flight test of the variable specific impulse magnetoplasma rocket (VASIMR) is tentatively scheduled for the Radiation and Technology Demonstration (RTD) in 2003. This mission to map the radiation environment out to several earth radii will employ both a Hall thruster and a VASIMR during its six months duration, beginning from low earth orbit. The mission will be powered by a solar array providing 12 kW of direct current electricity at 50 V. The VASIMR utilizes radiofrequency (RF) power both to generate a high-density plasma in a helicon source and to accelerate the plasma ions to high velocity by ion cyclotron resonance heating (ICRH). The VASIMR concept is being developed by the National Aeronautics and Space Administration (NASA) in collaboration with national laboratories and universities. Prototype plasma sources, RF amplifiers, and antennas are being developed in the experimental facilities of the Advanced Space Propulsion Laboratory (ASPL).

Baity, F.W.; Barber, G.C.; Carter, M.D.; Chang-Diaz, F.R.; Goulding, R.H.; McCaskill, G.E.; Sparks, D.O.; Squire, J.P.

1999-04-12T23:59:59.000Z

174

Resonant ring for testing of accelerator RF windows  

SciTech Connect

A klystron-driven resonant ring has been designed and assembled at the Los Alamos National Laboratory for use in the Accelerator Production of Tritium Project (APT). The ring was built to test rf windows for the 700 MHz section of the APT accelerator. The ring has been designed to apply an effective power of approximately 1 MW on test windows. Details of ring design, operation and performance will be presented.

Gerken, E.; Rees, D.; Roybal, W.; Cummings, K. [Los Alamos National Lab., NM (United States); Gahl, J.M. [Univ. of New Mexico, Albuquerque, NM (United States)

1997-09-01T23:59:59.000Z

175

Validation of protection provided by one brand of filtering facepiece respirator  

Science Conference Proceedings (OSTI)

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

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

1995-05-01T23:59:59.000Z

176

RF Choke for Standing Wave Structures and Flanges  

DOE Green Energy (OSTI)

SLAC participates in the U.S. High Gradient collaboration whose charter includes basic studies of rf breakdown properties in accelerating structures. These studies include experiments with different materials and construction methods for single cell standing wave accelerating structures. The most commonly used method of joining cells of such structures is the high temperature bonding and/or brazing in hydrogen and/or vacuum. These high temperature processes may not be suitable for some of the new materials that are under consideration. We propose to build structures from cells with an rf choke, taking the cell-to-cell junction out of the electromagnetic field region. These cells may be clamped together in a vacuum enclosure, the choke joint ensuring continuity of rf currents. Next, we propose a structure with a choke joint in a high gradient cell and a view port which may allow us microscopic, in-situ observation of the metal surface during high power tests. And third, we describe the design of a TM01 choke flange for these structures.

Yeremian, Anahid; /SLAC; Dolgashev, Valery; /SLAC; Tantawi, Sami; /SLAC

2012-07-03T23:59:59.000Z

177

Inhibition of respiration in cats by ELF electric fields. [Felis domestica  

SciTech Connect

Cats (Felis domestica) were exposed acutely to electric fields in the frequency range from 0.1 to 50 Hz using contact electrodes. A marked reduction in respiration rate was observed. The maximum sensitivity was of the order of 1 V/m at frequencies of 0.5-2 Hz. Using multiple electrode sites, it was found that the primary locus of action was near the first vertebra. No effects on cardiac frequency were observed at any frequency with fields up to those which caused visible neuromuscular stimulation.

Lockard, J.W. Jr.; Carstensen, E.L.; Morris, T.

1986-05-01T23:59:59.000Z

178

Fractional reaction-diffusion equations  

E-Print Network (OSTI)

In a series of papers, Saxena, Mathai, and Haubold (2002, 2004a, 2004b) derived solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which provide the extension of the work of Haubold and Mathai (1995, 2000). The subject of the present paper is to investigate the solution of a fractional reaction-diffusion equation. The results derived are of general nature and include the results reported earlier by many authors, notably by Jespersen, Metzler, and Fogedby (1999) for anomalous diffusion and del-Castillo-Negrete, Carreras, and Lynch (2003) for reaction-diffusion systems with L\\'evy flights. The solution has been developed in terms of the H-function in a compact form with the help of Laplace and Fourier transforms. Most of the results obtained are in a form suitable for numerical computation.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2006-04-21T23:59:59.000Z

179

Comparison of the response of bacterial luminescence and mitochondrial respiration to the effluent of an oil refinery  

Science Conference Proceedings (OSTI)

The effects of oil refinery effluents on rat mitochondrial respiration and on the luminescence of the bacterium Photobacterium phosphoreum were compared. Mitochondria from male Wistar rat livers were exposed to different concentrations of refinery effluents in a semiclosed 3-ml reaction vessel. Respiration was measured polarographically with an oxygen electrode. Effects on P. phosphoreum were measured by the standard test developed by Microbics. The mitochondrial method showed EC50s in the range from 1 to 7.5%, while Microtox gave EC50 in the range from 30 to 42%. The higher sensitivity of mitochondria may be exploited in the development of a sensitive biosensor for toxicity of oil refinery effluents.

Riisberg, M.; Bratlie, E.; Stenersen, J. [Univ. of Oslo (Norway)

1996-04-01T23:59:59.000Z

180

THE INFLUENCE OF CYSTEINEAMINE ON THE RESPIRATION AND BLOOD PRESSURE (TO THE MECHANISM OF THE PROTECTIVE ACTION OF CYSTEINEAMINE  

SciTech Connect

The influence of a therapeutic dose of cysteineamine on the blood pressure and respiration was studied. The investigations, staged on cats irradiated with 500 and 700 r, revealed that the best protective effect following the administration of cysteineamine took place when the dose amounted to 75 mg/kg. All the cysteineamine doses studied (30, 50, 75, and 100 mg/kg) produce a drop in the blood pressure and stimulation of respiration. The respiratory stimulation caused by cysteineamine introduction is weakened by cutting of the vagus nerves, denervation of carotid sinuses, or preliminary introduction of hexonium. (auth)

Smorodintseva, G.I.

1959-07-01T23:59:59.000Z

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.


181

RF system models for the CERN Large Hadron Collider with application to longitudinal dynamics  

Science Conference Proceedings (OSTI)

The LHC RF station-beam interaction strongly influences the longitudinal beam dynamics, both single bunch and collective effects. Non-linearities and noise generated within the Radio Frequency (RF) accelerating system interact with the beam and contribute to beam motion and longitudinal emittance blowup. Thus, the noise power spectrum of the RF accelerating voltage strongly affects the longitudinal beam distribution. Furthermore, the coupled-bunch instabilities are also directly affected by the RF components and the configuration of the Low Level RF (LLRF) feedback loops. In this work we present a formalism relating the longitudinal beam dynamics with the RF system configurations, an estimation of collective effects stability margins, and an evaluation of longitudinal sensitivity to various LLRF parameters and configurations.

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

2011-03-03T23:59:59.000Z

182

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

183

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

SciTech Connect

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

184

Surface Characterization of the LCLS RF Gun Cathode  

Science Conference Proceedings (OSTI)

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

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

2012-06-25T23:59:59.000Z

185

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

186

Optical Emission of Dusty RF Discharges: Experiment and Simulation  

Science Conference Proceedings (OSTI)

The spectral emission of argon atoms in a dusty radio frequence (RF) discharge has been investigated experimentally and in simulations. It was observed that the spatially and temporally resolved emission of the argon atoms in the dusty discharge was increased compared to the dust-free case during sheath expansion. The corresponding simulations have revealed that the dust trapped in the sheath of the discharge leads to a small, but important, increase of the amount of high-energy electrons that in turn leads to an increased argon emission.

Melzer, A.; Lewerentz, L.; Schneider, R. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Huebner, S. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Department of Applied Physics, Technical University Eindhoven, NL-5600 MB Eindhoven (Netherlands); Matyash, K. [Max-Planck-Institute for Plasma Physics, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, V. R. [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

2011-11-29T23:59:59.000Z

187

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

DOE Green Energy (OSTI)

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

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

2009-05-01T23:59:59.000Z

188

Field Emission Cathode Gating for RF Electron Guns (IN-04-039)  

Scientists at Argonne National Laboratory have created an innovative way to enhance the performance of radio frequency (RF) electron guns: a method of ...

189

Characterizing the impact of diffusive and advective soil gas transport on the measurement and interpretation of the isotopic signal of soil respiration  

E-Print Network (OSTI)

-state transport models. The affect of natural fluctuations in advective soil gas transport was little to nonCharacterizing the impact of diffusive and advective soil gas transport on the measurement signature of soil respiration, we seek to learn the isotopic composition of the carbon respired in the soil

Bond, Barbara J.

190

Fractionally total colouring Gn,p  

Science Conference Proceedings (OSTI)

We study the fractional total chromatic number of G"n","p as p varies from 0 to 1. We also present an algorithm that computes the fractional total chromatic number of a random graph in polynomial expected time. Keywords: Fractional total colouring, Graph colouring, Random graphs

Conor Meagher; Bruce Reed

2008-04-01T23:59:59.000Z

191

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

Science Conference Proceedings (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

192

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

SciTech Connect

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

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

2012-11-26T23:59:59.000Z

193

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

NLE Websites -- All DOE Office Websites (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

194

Plasma properties of RF magnetron sputtering system using Zn target  

Science Conference Proceedings (OSTI)

In the present work, we investigate the fundamental properties of magnetron sputtering plasma using Zn target and its deposited Zn thin film. The magnetron sputtering plasma was produced using radio frequency (RF) power supply and Argon (Ar) as ambient gas. A Langmuir probe was used to collect the current from the plasma and from the current intensity, we calculate the electron density and electron temperature. The properties of Zn sputtering plasma at various discharge conditions were studied. At the RF power ranging from 20 to 100 W and gas pressure 5 mTorr, we found that the electron temperature was almost unchanged between 2-2.5 eV. On the other hand, the electron temperature increased drastically from 6 Multiplication-Sign 10{sup 9} to 1 Multiplication-Sign 10{sup 10}cm{sup -3} when the discharge gas pressure increased from 5 to 10 mTorr. The electron microscope images show that the grain size of Zn thin film increase when the discharge power is increased. This may be due to the enhancement of plasma density and sputtered Zn density.

Nafarizal, N.; Andreas Albert, A. R.; Sharifah Amirah, A. S.; Salwa, O.; Riyaz Ahmad, M. A. [Microelectronic and Nanotechnology - Shamsuddin Research Centre (MiNT-SRC), Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

2012-06-29T23:59:59.000Z

195

High Gradient Operation with the CEBAF Upgrade RF Control System  

SciTech Connect

The CEBAF Accelerator at Jefferson Lab is presently a 6 GeV five pass electron accelerator consisting of two superconducting linacs joined by independent magnetic transport arcs. Energy will be upgraded to 12 GeV with the addition of 10 new high gradient cryomodules (17+ MV/m). The higher gradients pose significant challenges beyond what the present analog low level RF (LLRF) control systems can handle reliably; therefore, a new LLRF control system is needed. A prototype system has been developed incorporating a large FPGA and using digital down and up conversion to minimize the need for analog components. The new system is more flexible and less susceptible to drifts and component nonlinearities. Because resonance control is critical to reach high gradients quickly, the new cryomodules will include a piezoelectric tuner for each cavity, and the LLRF controls must incorporate both feedback and feed-forward methods to achieve optimal resonance control performance. This paper discusses development of the new RF system, system performance for phase and amplitude stability and resonance control under Lorentz detuning measured during recent tests on a prototype cryomodule.

J. Hovater; G. Davis; Hai Dong; Alicia Hofler; Lawrence King; John Musson; Tomasz Plawski

2006-08-16T23:59:59.000Z

196

POST OAK SAVANNA IN TRANSITION: JUNIPER ENCROACHMENT AND CLIMATE CHANGE ALTER GRASSLAND SOIL RESPIRATION  

E-Print Network (OSTI)

The amount of carbon flux from soils on a global scale is estimated at over 75 x 1015 g C yr-1. Climate change is projected to affect regional environmental conditions, raising temperatures and altering precipitation patterns. The semi-arid environment of the post oak savannah is an ecotone in transition. As juniper encroachment replaces native grasses, changes in species composition may affect carbon cycling. Given that water is limiting in this warm-temperate climate, changing precipitation patterns coupled with higher temperatures may alter function in addition to the structure of savanna ecosystems. The Texas Warming and Rainfall Manipulation (Texas WaRM) experiment is designed to test global climate change factors and the responses of the dominant tree, eastern red cedar (Juniperus virginiana) and grass species, little blue stem (Schizachyrium scoparium). We compared respiratory carbon losses of soils between eastern red cedar and little blue stem plots subjected to warming (1.5 °C) and summer drought treatments to determine the effects of climate change on integrated below-ground CO2 efflux. During the June to August months, soil CO2 efflux rates were determined and compared among treatments in relation to soil temperature and moisture. Overall, juniper and grass plots had relatively equal CO2 respiratory flux, although it generally has more associated roots and microbial biomass. Soil respiration in grass plots appeared more responsive to changes in soil moisture, while juniper maintained more consistent respiration under increasing heat and declining moisture conditions during summer drought. With equivalent soil CO2 efflux and reduced responsiveness to warming or drought, coupled with increased woody biomass, juniper encroachment might have positive effects on the carbon cycle of this transitional biome through increased carbon sequestration. Determining these transitional characteristics of a changing carbon budget will aid in projecting climate change impacts on carbon cycling and provide management options for native and managed vegetation.

Thompson, Bennie

2011-05-01T23:59:59.000Z

197

Involvement of a Membrane-Bound Class III Adenylate Cyclase in Regulation of Anaerobic Respiration in Shewanella oneidensis MR-1  

Science Conference Proceedings (OSTI)

Unlike other bacteria that use FNR to regulate anaerobic respiration, Shewanella oneidensis MR-1 uses the cyclic AMP receptor protein (CRP) for this purpose. Three putative genes, cyaA, cyaB, and cyaC, predicted to encode class I, class IV, and class III adenylate cyclases, respectively, have been identified in the genome sequence of this bacterium. Functional validation through complementation of an Escherichia coli cya mutant confirmed that these genes encode proteins with adenylate cyclase activities. Chromosomal deletion of either cyaA or cyaB did not affect anaerobic respiration with fumarate, dimethyl sulfoxide (DMSO), or Fe(III), whereas deletion of cyaC caused deficiencies in respiration with DMSO and Fe(III) and, to a lesser extent, with fumarate. A phenotype similar to that of a crp mutant, which lacks the ability to grow anaerobically with DMSO, fumarate, and Fe(III), was obtained when both cyaA and cyaC were deleted. Microarray analysis of gene expression in the crp and cyaC mutants revealed the involvement of both genes in the regulation of key respiratory pathways, such as DMSO, fumarate, and Fe(III) reduction. Additionally, several genes associated with plasmid replication, flagellum biosynthesis, and electron transport were differentially expressed in the cyaC mutant but not in the crp mutant. Our results indicated that CyaC plays a major role in regulating anaerobic respiration and may contribute to additional signaling pathways independent of CRP.

Charania, M.; Brockman, K. L.; Zhang, Y.; Banerjee, A.; Pinchuk, Grigoriy E.; Fredrickson, Jim K.; Beliaev, Alex S.; Saffarini, Daad

2009-07-01T23:59:59.000Z

198

Involvement of a Membrane-Bound Class III Adenylate Cyclase in Regulation of Anaerobic Respiration in Shewanella oneidensis MR-1  

Science Conference Proceedings (OSTI)

Unlike other bacteria that use FNR to regulate anaerobic respiration, S. oneidensis MR-1 uses the cAMP receptor protein, CRP, for this purpose. Three putative genes, cyaA, cyaB, and cyaC, predicted to encode class I, class IV, and class III adenylate cyclases respectively, have been identified in the genome sequence of this bacterium. Functional validation through complementation of an E. coli cya mutant confirmed that these genes encode proteins with adenylate cyclase activities. Chromosomal deletion of either cyaA or cyaB did not affect anaerobic respiration with fumarate, DMSO, or Fe(III), whereas the deletion of cyaC caused deficiencies in respiration with DMSO and Fe(III), and to a lesser extent with fumarate. A phenotype similar to that of a crp mutant, which lacks the ability to grow anaerobically with DMSO, fumarate, and Fe(III), was obtained when both cyaA and cyaC were deleted. Microarray analysis of gene expression in the crp and the cyaC mutants revealed the involvement of both genes in the regulation of key respiratory pathways such as DMSO, fumarate, and Fe(III) reduction. Additionally, several genes associated with plasmid replication, flagella biosynthesis, and electron transport, were differentially expressed in the cyaC mutant, but not in the crp mutant. Our results indicated that CyaC plays a major role in regulating anaerobic respiration, and may contribute to additional signaling pathways independent of CRP.

Charania, M.; Brockman, K.; Zhang, Yang; Banerjee, A.; Pinchuk, Grigoriy; Fredrickson, Jim K.; Beliaev, Alex S.; Saffarini, Daad

2009-07-01T23:59:59.000Z

199

Effects of light on respiration and development of photosynthetic cells. Renewal application and progress report, March 1-November 1, 1980  

SciTech Connect

The oxyhydrogen reaction in the presence and absence of CO/sub 2/ was studied in H/sub 2/- adapted Scenedesmus obliquus by monitoring the initial rates of H/sub 2/, O/sub 2/, and /sup 14/CO/sub 2/ uptake and the effect of inhibitors on these rates. Glucose and acetate respiration was competitive with H/sub 2/ uptake. KCN inhibited equally respiration and the oxyhydrogen reaction in the presence and absence of CO/sub 2/. It was concluded that the oxyhydrogen reaction both in the absence and presence of CO/sub 2/ has properties in common with components of respiration and photosynthesis. Participation of these two processes in the oxyhydrogen reaction would require a closely linked shuttle between mitochondrion and chloroplast. Protoplasts and chloroplasts will be isolated from a H/sub 2/-adapted alga in order to elucidate the cooperation between the two organelles. Acetate was shown to stimulate H/sub 2/ photoproduction in H/sub 2/-adapted algae even more so than an uncoupler of electron transport. The role of these compounds will be evaluated either in terms of the glyoxylate cycle or electron acceptors resulting in formation of alcohols. The term chloroplast respiration was proposed to account for the breakdown of polyglucan within the chloroplast. A means of reoxidizing reduced pyridine nucleotide was required to complete the cycle. A new enzyme ascorbic acid reduced pyridine nucleotide peroxidase was isolated from the chloroplast. The characterization of this enzyme will continue.

Gibbs, M.

1980-11-20T23:59:59.000Z

200

Fractional oscillator process with two indices  

E-Print Network (OSTI)

We introduce a new fractional oscillator process which can be obtained as solution of a stochastic differential equation with two fractional orders. Basic properties such as fractal dimension and short range dependence of the process are studied by considering the asymptotic properties of its covariance function. The fluctuation--dissipation relation of the process is investigated. The fractional oscillator process can be regarded as one-dimensional fractional Euclidean Klein-Gordon field, which can be obtained by applying the Parisi-Wu stochastic quantization method to a nonlocal Euclidean action. The Casimir energy associated with the fractional field at positive temperature is calculated by using the zeta function regularization technique.

S. C. Lim; L. P. Teo

2008-04-24T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
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201

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

SciTech Connect

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

202

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

E-Print Network (OSTI)

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

Artuso, Florinda

203

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.

204

RF Breakdown Studies Using a 1.3 GHZ Test Cell  

DOE Green Energy (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. Recent studies have shown that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas without the need for long conditioning times, because the dense gas can dramatically reduce dark currents and multipacting. In this project we use this high pressure technique to suppress effects of residual vacuum and geometry found in evacuated cavities to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. A 1.3-GHz RF test cell with replaceable electrodes (e.g. Mo, Cu, Be, W, and Nb) and pressure barrier capable of operating both at high pressure and in vacuum has been designed and built, and preliminary testing has been completed. A series of detailed experiments is planned at the Argonne Wakefield Accelerator. At the same time, computer simulations of the RF Breakdown process will be carried out to help develop a consistent physics model of RF Breakdown. In order to study the effect of the radiofrequency on RF Breakdown, a second test cell will be designed, fabricated, and tested at a lower frequency, most likely 402.5 MHz.

Sah, R.; Johnson, R.P.; Neubauer, M.; /Muons Inc., Batavia; Conde, M.; Gai, W.; /Argonne; Moretti, A.; Popovic, M.; Yonehara, K.; /Fermilab; Byrd, J.; Li, D.; /LBL, Berkeley; BastaniNejad, M.; /Old Dominion U.

2009-05-01T23:59:59.000Z

205

RF Breakdown Studies Using a 1.3-GHz Text Cell  

DOE Green Energy (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. Recent studies have shown that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas without the need for long conditioning times, because the dense gas can dramatically reduce dark currents and multipacting. In this project we use this high pressure technique to suppress effects of residual vacuum and geometry found in evacuated cavities to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. A 1.3-GHz RF test cell with replaceable electrodes (e.g. Mo, Cu, Be, W, and Nb) and pressure barrier capable of operating both at high pressure and in vacuum has been designed and built, and preliminary testing has been completed. A series of detailed experiments is planned at the Argonne Wakefield Accelerator. At the same time, computer simulations of the RF Breakdown process will be carried out to help develop a consistent physics model of RF Breakdown. In order to study the effect of the radiofrequency on RF Breakdown, a second test cell will be designed, fabricated, and tested at a lower frequency, most likely 402.5 MHz.

Sah, R.; Johnson, R. P.; Neubauer, M.; Conde, M.; Gai, W.; Moretti, A.; Popovic, M.; Yonehara, K.; Byrd, J.; Li, D.; BastaniNejad, M.; Elmustafa, M.

2009-05-04T23:59:59.000Z

206

Influence of the film properties on the plasma etching dynamics of rf-sputtered indium zinc oxide layers  

Science Conference Proceedings (OSTI)

The etching characteristics of indium zinc oxide (IZO) films were investigated using a high-density plasma in Ar, Ar/Cl{sub 2}, and Ar/CH{sub 4}/H{sub 2} chemistries. The IZO layers were deposited by means of rf magnetron sputtering, in which the target composition and growth temperature were varied to selectively tune the film properties. X-ray diffraction, elastic recoil detection, and Rutherford backscattering spectroscopy were used to determine the crystallization quality, atomic density, and composition of the as-deposited IZO films. As the In/(In+Zn) composition ratio in the IZO layer increases, the etch yield in Ar and Ar/Cl{sub 2} plasmas remains fairly constant, indicating that the etching dynamic is essentially independent of the film properties. In sharp contrast, a strong increase of the IZO etch yield with the In/(In+Zn) fraction is observed in Ar/CH{sub 4}/H{sub 2} plasma due to the preferential desorption of the group-III etch products. By comparing these experimental data to the predictions of a simple rate model accounting for preferential desorption effects, it is concluded that the balance between etching and polymer deposition in the Ar/CH{sub 4}/H{sub 2} plasma plays an important role in the evolution of the IZO etch rate with the In concentration fraction.

Stafford, L.; Lim, W. T.; Pearton, S. J.; Chicoine, M.; Gujrathi, S.; Schiettekatte, F.; Park, Jae-Soung; Song, Ju-Il; Heo, Young-Woo; Lee, Joon-Hyung; Kim, Jeong-Joo; Kravchenko, I. I. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Departement de Physique, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); Department of Inorganic Materials Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

2007-07-15T23:59:59.000Z

207

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

208

1.3 GHz superconducting RF cavity program at Fermilab  

SciTech Connect

At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

2011-03-01T23:59:59.000Z

209

Cerenkov Radiator Driven by a Superconducting RF Electron Gun  

SciTech Connect

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

210

GaAs Films Prepared by RF-Magnetron Sputtering  

DOE Green Energy (OSTI)

The authors reported on the optical absorption, adhesion, and microstructure of RF-magnetron sputtered films of hydrogenated amorphous and microcrystalline GaAs films for the 1 to 25 {micro}m infrared wavelength rate. Sputtering parameters which were varied include sputtering power, temperature and pressure, and hydrogen sputtering-gas concentration. TEM results show a sharp transition from purely amorphous GaAs to a mixture of microcrystalline GaAs in an amorphous matrix at 34 {+-} 2 C. By optimizing the sputtering parameters, the optical absorption coefficient can be decreased below 100 cm{sup -1} for wavelengths greater than about 1.25 {micro}m. These results represent the lowest reported values of optical absorption for sputtered films of GaAs directly measured by spectrophotometry for the near-infrared wavelength region.

L.H. Ouyang; D.L. Rode; T. Zulkifli; B. Abraham-Shrauner; N. Lewis; M.R. Freeman

2001-08-01T23:59:59.000Z

211

Active RF Pulse Compression Using An Electrically Controlled Semiconductor Switch  

SciTech Connect

First we review the theory of active pulse compression systems using resonant delay lines. Then we describe the design of an electrically controlled semiconductor active switch. The switch comprises an active window and an overmoded waveguide three-port network. The active window is based on a four-inch silicon wafer which has 960 PIN diodes. These are spatially combined in an overmoded waveguide. We describe the philosophy and design methodology for the three-port network and the active window. We then present the results of using this device to compress 11.4 GHz RF signals with high compression ratios. We show how the system can be used with amplifier like sources, in which one can change the phase of the source by manipulating the input to the source. We also show how the active switch can be used to compress a pulse from an oscillator like sources, which is not possible with passive pulse compression systems.

Guo, Jiquan; Tantawi, Sami; /SLAC

2007-01-10T23:59:59.000Z

212

SLAC collider injector, RF-drive synchronization and trigger electronics, and 15-AMP thermionic-gun development  

SciTech Connect

The rf drive system for the Collider Injector Development (EL CID) including laser timing, subharmonic buncher drive and phasing, and accelerator rf drive is described. The rf synchronized master trigger generation scheme for the collider is outlined. Also, a 15 amp peak, 200 kV short pulse gun being developed at SLAC as a backup to the Sinclair laser gun is described.

Koontz, R.; Miller, R.; McKinney, T.; Wilmunder, A.

1981-02-01T23:59:59.000Z

213

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

SciTech Connect

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

214

Continued fraction as a discrete nonlinear transform  

SciTech Connect

The connection between a Taylor series and a continued fraction involves a nonlinear relation between the Taylor coefficients [l brace][ital a][sub [ital n

Bender, C.M. (Department of Physics, Washington University, St. Louis, Missouri 63130 (United States)); Milton, K.A. (Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019 (United States))

1994-01-01T23:59:59.000Z

215

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

216

Hydrolysis and fractionation of lignocellulosic biomass ...  

A multi-function process is described for the hydrolysis and fractionation of lignocellulosic biomass to separate hemicellulosic sugars from other bio ...

217

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

SciTech Connect

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

218

Evaluation of Microwave Steam Bags for the Decontamination of Filtering Facepiece Respirators  

E-Print Network (OSTI)

Reusing filtering facepiece respirators (FFRs) has been suggested as a strategy to conserve available supplies for home and healthcare environments during an influenza pandemic. For reuse to be possible, used FFRs must be decontaminated before redonning to reduce the risk of virus transmission; however, there are no approved methods for FFR decontamination. An effective method must reduce the microbial threat, maintain the function of the FFR, and present no residual chemical hazard. The method should be readily available, inexpensive and easily implemented by healthcare workers and the general public. Many of the general decontamination protocols used in healthcare and home settings are unable to address all of the desired qualities of an efficient FFR decontamination protocol. The goal of this study is to evaluate the use of two commercially available steam bags, marketed to the public for disinfecting infant feeding equipment, for FFR decontamination. The FFRs were decontaminated with microwave generated steam following the manufacturers ’ instructions then evaluated for water absorption and filtration efficiency for up to three steam exposures. Water absorption of the FFR was found to be model specific as FFRs constructed with hydrophilic materials absorbed more water. The steam had little effect on FFR performance as filtration efficiency of the treated FFRs remained above 95%. The decontamination efficacy of the steam bag was assessed using bacteriophage MS2 as a surrogate for a pathogenic virus. The tested steam bags were found to be 99.9 % effective for inactivating MS2 on FFRs; however, more research is required to

Edward M. Fisher; Jessica L. Williams; Ronald E. Shaffer

2011-01-01T23:59:59.000Z

219

Radio-Frequency (RF) Devices for Safeguards: Where We Are and Where We Need to Go  

Science Conference Proceedings (OSTI)

Radio-Frequency (RF) devices have revolutionized many aspects of modern industrial processes. RF technology can enable wireless communication for tag identification, sensor communication, and asset tracking. Radio-frequency identification (RFID) is a technology that utilizes wireless communication to interrogate and identify an electronic tag attached to an item in order to identify the item. The technology can come in many forms: passive or active tags, low to ultra-wideband frequencies, small paper-thin tags to brick-sized units, and simple tags or highly integrated sensor packages. RF technology, and specifically RFID, has been applied widely in commercial markets for inventory, supply chain management, and asset tracking. Several recent studies have demonstrated the safeguards benefits of utilizing RFID versus conventional inventory tagging methods for tracking nuclear material. These studies have indicated that the RF requirements for safeguards functions are more stringent than the RF requirements for other inventory tracking and accounting applications. Additionally, other requirements must be addressed, including environmental and operating conditions, authentication, and tag location and attachment. Facility restrictions on radio spectrum, method of tag attachment, and sensitivity of the data collected impact the tag selection and system design. More important, the intended use of the system must be considered. The requirements for using RF to simply replace or supplement container identifiers such as bar codes that facilitate the inventory function will differ greatly from the requirements for deploying RF for unattended monitoring applications. Several studies have investigated these considerations to advance commercial RF devices for safeguards use, and a number of system concepts have been developed. This paper will provide an overview of past studies and current technologies, and will investigate the requirements, existing gaps, and several potential next steps for advancing RF techniques for safeguards use.

Rowe, Nathan C [ORNL; Younkin, James R [ORNL; Pickett, Chris A [ORNL; Whitaker, J Michael [ORNL

2011-01-01T23:59:59.000Z

220

Approximate Integrals of rf-driven Particle Motion in Magnetic Field  

DOE Green Energy (OSTI)

For a particle moving in nonuniform magnetic field under the action of an rf wave, ponderomotive effects result from rf-driven oscillations nonlinearly coupled with Larmor rotation. Using Lagrangian and Hamiltonian formalism, we show how, despite this coupling, two independent integrals of the particle motion are approximately conserved. Those are the magnetic moment of free Larmor rotation and the quasi-energy of the guiding center motion parallel to the magnetic field. Under the assumption of non-resonant interaction of the particle with the rf field, these integrals represent adiabatic invariants of the particle motion.

I.Y. Dodin; N.J. Fisch

2004-04-26T23:59:59.000Z

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.


221

Void Fraction Instrument operation and maintenance manual  

SciTech Connect

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

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

1994-09-01T23:59:59.000Z

222

Time fractional development of quantum systems  

Science Conference Proceedings (OSTI)

In this study, the effect of time fractionalization on the development of quantum systems is taken under consideration by making use of fractional calculus. In this context, a Mittag-Leffler function is introduced as an important mathematical tool in the generalization of the evolution operator. In order to investigate the time fractional evolution of the quantum (nano) systems, time fractional forms of motion are obtained for a Schroedinger equation and a Heisenberg equation. As an application of the concomitant formalism, the wave functions, energy eigenvalues, and probability densities of the potential well and harmonic oscillator are time fractionally obtained via the fractional derivative order {alpha}, which is a measure of the fractality of time. In the case {alpha}=1, where time becomes homogenous and continuous, traditional physical conclusions are recovered. Since energy and time are conjugate to each other, the fractional derivative order {alpha} is relevant to time. It is understood that the fractionalization of time gives rise to energy fluctuations of the quantum (nano) systems.

Ertik, Hueseyin; Demirhan, Dogan; Sirin, Hueseyin; Bueyuekkilic, Fevzi [Department of Physics, Science Faculty, Ege University, Bornova, Izmir 35100 (Turkey)

2010-08-15T23:59:59.000Z

223

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

SciTech Connect

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

224

Dynamics of Flat Bunches with Second Harmonic RF  

Science Conference Proceedings (OSTI)

We investigate the dynamics of longitudinally flat bunches created with a second harmonic cavity in a high energy collider. We study Landau damping in a second harmonic cavity with analytical and numerical methods. The latter include particle tracking and evolution of the phase space density. The results are interpreted in the context of possible application to the LHC. A possible path to a luminosity upgrade at the LHC is through the creation of longitudinally flat bunches. They can increase the luminosity roughly by 40% when the beam intensities are at the beam-beam limit. Lower momentum spread which can reduce backgrounds and make collimation easier as well lower peak fields which can mitigate electron cloud effects are other advantages. Use of a second harmonic rf system is a frequently studied method to create such flat bunches. Here we consider some aspects of longitudinal dynamics of these bunches in the LHC at top energy. First we consider intensity limits set by the loss of Landau damping against rigid dipole oscillations. Next we describe numerical simulations using both particle tracking and evolution of the phase space density. These simulations address the consequences of driving a bunch at a frequency that corresponds to the maximum of the synchrotron frequency.

Sen, Tanaji; /Fermilab; Bhat, Chandra; /Fermilab; Kim, Hyung Jin; /Fermilab; Ostiguy, Jean-Francois; /Fermilab

2010-05-01T23:59:59.000Z

225

A new rf structure for intermediate-velocity particles  

Science Conference Proceedings (OSTI)

This paper describes an rf structure with high shunt impedance and good field stability for particle velocities o.1 {le} {beta} {le} 0.5. Traditionally, the drift-tube linac (DTL) has been the structure of choice for this velocity range. The new structure, called a coupled-cavity drift-tube linac (CCDTL), combines features of the Alvarez DTL and the {pi}-mode coupled-cavity linac (CCL). Each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between gaps is {gamma}{lambda}. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180{degrees}. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. We will discuss 2-D and 3-D electromagnetic code calculations, and some initial measurements on a low-power model of a CCDTL. We will compare shunt impedance calculations for DTL, CCL, and CCDTL structures. The CCDTL has potential application for a wide range of ion linacs. For example, high-intensity proton linacs could use the CCDTL instead of a DTL up to an energy of about 200 MeV. Another example is a stand-alone, low-duty, low-current, very high gradient, proton, cancer therapy machine. The advantage for this application would be a saving in the cost of the machine because the linac would be short.

Billen, J.H.; Krawczyk, F.L.; Wood, R.L.; Young, L.M.

1994-09-01T23:59:59.000Z

226

Test results of the AGS Booster low frequency RF system  

Science Conference Proceedings (OSTI)

The Band II RF system was originally built to support the Booster operations during the acceleration of heavy ions. Designed to sweep from 0.6 to 2.5 MHz, it was build and successfully tested over a much broader range reaching 4 MHz. Voltages up to more than 20 kV were reached over the design frequency range. The system consists of two stations, each of which is made of one single gap cavity directly driven by a grounded cathode push pull power amplifier. The low Q high permeability ferrites needed in the coaxial cavity in order to reach the lower end of the band make tuning extremely easy. Both systems were thoroughly tested both at single frequencies and on a sweep and are now installed in the ring, ready for operations. Static measurements showed no high-loss effects. The Band 11 system has been fully described in a previous paper; presented here are the results of the ``bench`` tests that lead to important performance improvements.

Sanders, R.T.; Cameron, P.; Damm, R.; Dunbar, A.; Goldman, M.; Kasha, D.; McNerney, A.; Meth, M.; Ratti, A.; Spitz, R.

1993-06-01T23:59:59.000Z

227

High gain proportional rf control stability at TESLA cavities Elmar Vogel  

E-Print Network (OSTI)

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

228

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,

229

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

SciTech Connect

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

230

C-Band High Power RF Generation and Extraction Using a Dielectric...  

NLE Websites -- All DOE Office Websites (Extended Search)

C-BAND HIGH POWER RF GENERATION AND EXTRACTION USING A DIELECTRIC LOADED WAVEGUIDE* F. Gao , M. Conde, W. Gai, R. Konecny, W. Liu, J. Power, Z. Yusof ANL, Argonne, IL 60439,...

231

Delta-Sigma digital-RF modulation for high data rate transmitters  

E-Print Network (OSTI)

A low power, wideband wireless transmitter utilizing [Delta]-[Sigma] direct digital modulation of an RF carrier is presented. The transmitter architecture replaces high dynamic range analog circuits with high speed digital ...

Jerng, Albert

2007-01-01T23:59:59.000Z

232

Closed-cell 201.25 MHz RF structures for a muon cooling channel  

DOE Green Energy (OSTI)

We report on the research and development of high gradient low frequency closed-cell structures for possible use in a muon cooling channel. The presence of strong magnetic fields precludes the use of superconducting RF. These multi-cell structures have the ''beam iris'' closed by conducting oils, grids of tubes or other isolating structures. This greatly increases the shunt impedance and also allows the individually powered cells to be set independently to any phase. The isolating structure must be made using a very small amount of low-Z material to avoid unacceptable scattering of the muon beam. Various cell designs and methods of closure are presented and compared. The problems of RF heating and breakdown at high gradient are discussed with regard to the vulnerable isolating structures. RF, thermal and stress analyses are presented and the integration of the RF with the solenoid cryostat and liquid hydrogen absorbers is considered.

Rimmer, R.; Hartman, N.; Ladran, A.; Li, D.; Moretti, A.; Jurgens, T.

2001-06-01T23:59:59.000Z

233

Molecular-beam, laser-rf, double-resonance studies of calcium monohalide radicals  

SciTech Connect

The molecular-beam, laser-rf, double-resonance technique has been described a number of times. In essence, the occurrence of a radiofrequency (rf) transition in the electronic ground state of the molecule under study is detected by an increase in the laser-induced fluorescence of the molecular beam when the rf is on resonance. The technique makes it possible to measure small energy splittings (normally spin-rotational or hyperfine) in the electronic ground state of a molecule to an absolute precision of 1 kHz. The sensitivity of the technique is high because even a very small increase in fluorescence can be easily seen if the rf is swept repeatedly and digital data-handling techniques are used. The technique is useful for ionic as well as for neutral atoms and molecules.

Childs, W.J.; Cok, D.R.; Goodman, L.S.

1981-01-01T23:59:59.000Z

234

RF Cavity R&D at LBNL for the NLC Damping Rings, FY 1999  

NLE Websites -- All DOE Office Websites (Extended Search)

3 031299 RF Cavity R&D at LBNL for the NLC Damping Rings, FY1999 December 3, 1999 R. Rimmer, J.N. Corlett, G. Koehler, D. Li, N. Hartmann, J. Rasson, T.Saleh Lawrence Berkeley...

235

Wafer-scale 3D integration of silicon-on-insulator RF amplifiers  

E-Print Network (OSTI)

RF amplifiers are demonstrated using a three- dimensional (3D) wafer-scale integration technology based on silicon-on-insulator (SOI) CMOS process. This new 3D implementation reduces the amplifier size and shortens ...

Keast, Craig L.

236

Report on High Power rf Testing of Quartz Based DLA Structure  

NLE Websites -- All DOE Office Websites (Extended Search)

2 March, 2006 Report on High Power rf Testing of Quartz Based DLA Structure at NRL C. Jing, and R. Konecny Abstract: In this article, we report the experimental results of high...

237

RF Power Detector/Monitor Upgrade for the 500MHz Systems at the ALS  

E-Print Network (OSTI)

THE 500MHZ SYSTEMS AT THE ALS* K. Baptiste, LBNL, Berkeley,In the Advanced Light Source (ALS) Booster Ring and Storagedetectors in service in the ALS Storage Ring RF System only

Baptiste, K.

2003-01-01T23:59:59.000Z

238

Optimal RF Conditioning of Advanced Photon Source (APS) Fundamental Power Coupler  

E-Print Network (OSTI)

Experience at many laboratories regarding conditioning of RF Fundamental Power Couplers (FPC) has shown that it is a very apprehensive and laborious process. While the principle should remain unchanged, which is to gradually increase the rf power applied to the coupler while monitoring the vacuum level, the methodology is sometime different. With coupler lifetime being finite, some RF conditioning methods may be more conservative than others. The basic principle of coupler conditioning is to avoid the phenomena of metallisation, violent electrical discharges or other possible destructive phenomena. This document summarizes an optimized method which has demonstrated its effectiveness and for which the fundamental principles are: • Regulate RF power as a function of vacuum pressure around the coupler as fast as possible. • Apply a longer repetition period than the vacuum reading delay. • Follow the bare principle: low energy for low risk, by delivering pulses to the not yet conditioned coupler, initially...

Montesinos, E

2013-01-01T23:59:59.000Z

239

Brief evaluation of the control and rf systems in the Clinton P. Anderson Meson Physics Facility  

SciTech Connect

- From seminar on high-energy accelerator science; Tokyo and Tsukuba, Japan (5 Nov 1973). The design and operating experience with the computer control system and the rf power systems for the LAMPF linac are outlined. (WHK)

Hagerman, D.C.

1973-01-01T23:59:59.000Z

240

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

SciTech Connect

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

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

High-power testing of PEP-II RF cavity windows  

SciTech Connect

We describe the high power testing of RF cavity windows for the PEP-II B factory. The window is designed for continuous operation at 476 MHz with up to 500 kW throughput and has been tested to full power using a modified PEP Klystron. The windows use an anti-multipactor coating on the vacuum side and the application and processing of this layer is discussed. The high power test configuration, RF processing history and high power performance are described.

Neubauer, M.; Allen, M.; Fant, K.; Hill, A.; Hoyt, M.; Judkins, J.; Schwarz, H. [Stanford Linear Accelerator Center, CA (United States); Rimmer, R.A. [Lawrence Berkeley National Lab., CA (United States)

1996-06-01T23:59:59.000Z

242

Some issues on the RF system in the 3 GeV Fermilab pre-booster  

SciTech Connect

Some issues are presented on the rf system in the future Fermilab prebooster, which accelerates 4 bunches each containing 0.25 x 10{sub 14} protons from 1 to 3 GeV kinetic energy. The problem of beam loading is discussed. The proposal of having a non-tunable fixed-frequency rf system is investigated. Robinson's criteria for phase stability are checked and possible Robinson instability growth is computed.

Ng, K. Y.

1998-06-01T23:59:59.000Z

243

The upgraded rf system for the AGS and high intensity proton beams  

SciTech Connect

The AGS has been upgraded over the past three years to produce a record beam intensity of 6 {times} 10{sup 13} protons per pulse for the fixed-target physics program. The major elements of the upgrade are: the new 1.5 GeV Booster synchrotron, the main magnet power supply, a high frequency longitudinal dilution cavity, a feedback damper for transverse instabilities, a fast gamma transition jump system, and a new high-power rf system. The new rf system and its role in achieving the high intensity goal are the subjects of this report. The rf system is heavily beam loaded, with 7 Amps of rf current in the beam and a peak power of 0.75 MW delivered to the beam by ten cavities. As an example of the scale of beam loading, at one point in the acceleration cycle the cavities are operated at 1.5 kV/gap; whereas, were it not for the new power amplifiers, the beam-induced voltage on the cavities would be over 25 kV/gap. The upgraded rf system, comprising: new power amplifiers, wide band rf feedback, improved cavities, and new low-level beam control electronics, is described. Results of measurements with beam, which characterize the system`s performance, are presented. A typical high intensity acceleration cycle is described with emphasis on the key challenges of beam loading.

Brennan, J.M. [Brookhaven National Lab., Upton, NY (United States). AGS Dept.

1995-05-01T23:59:59.000Z

244

The upgrade project for the RF system for the Brookhaven AGS  

SciTech Connect

The AGS operates a varied program of proton, heavy ion, and polarized proton acceleration for fixed-target experiments and will soon serve as the injector of these beams into the Relativistic Heavy Ion Collider, RHIC. The new Booster synchrotron extends the range of intensities and masses that can be accelerated. The 1.5 GeV injection energy increases the space charge limit by a factor of four to more than 6 {times} 10{sup 13} protons per pulse. To accommodate the increased beam current the rf system will be upgraded to provide more power and lower impedance to the beam. The flexibility of the rf system will also be enhanced by virtue of a new rf beam control system and installation of individual tuning servos for the ten rf cavities. The fundamental necessity for upgrading the rf system is to deliver more power to the accelerating beam. Three key ingredients of the upgrade project addressing this problem is (1) new power amplifiers provide the necessary power, and are closely coupled to the cavities, (2) wideband rf feedback reduces the effective impedance by a factor of 10, and (3) the capacitors loading the acceleration gaps (four per cavity) are increased from 275 pF to 600 pF.

Brennan, J.M.; Ciardullo, D.J.; Hayes, T.; Meth, M.; McNerney, A.J.; Otis, A.; Pirkl, W.; Sanders, R.; Spitz, R.; Toldo, F.; Zaltsman, A.

1993-06-01T23:59:59.000Z

245

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

SciTech Connect

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

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

2011-01-01T23:59:59.000Z

246

Edge Excitations in Fractional Chern Insulators  

E-Print Network (OSTI)

Recent theoretical works have demonstrated the realization of fractional quantum anomalous Hall states (also called fractional Chern insulators) in topological flat band lattice models without an external magnetic field. Such newly proposed lattice systems play a vital role to obtain a large class of fractional topological phases. Here we report the exact numerical studies of edge excitations for such systems in a disk geometry loaded with hard-core bosons, which will serve as a more viable experimental probe for such topologically ordered states. We find convincing numerical evidence of a series of edge excitations characterized by the chiral Luttinger liquid theory for the bosonic fractional Chern insulators in both the honeycomb disk Haldane model and the kagom\\'{e}-lattice disk model. We further verify these current-carrying chiral edge states by inserting a central flux to test their compressibility.

Wei-Wei Luo; Wen-Chao Chen; Yi-Fei Wang; Chang-De Gong

2013-04-16T23:59:59.000Z

247

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

248

QUANTIFICATION OF PHASE FRACTION AND AMORPHOUS ...  

Science Conference Proceedings (OSTI)

... Results for a sample consisting of nearly equal mass fractions of Al2O3, CaF2, and ZnO, along with values reported by the other round-robin ...

2001-02-27T23:59:59.000Z

249

Maximizing Tumor Immunity With Fractionated Radiation  

Science Conference Proceedings (OSTI)

Purpose: Technologic advances have led to increased clinical use of higher-sized fractions of radiation dose and higher total doses. How these modify the pathways involved in tumor cell death, normal tissue response, and signaling to the immune system has been inadequately explored. Here we ask how radiation dose and fraction size affect antitumor immunity, the suppression thereof, and how this might relate to tumor control. Methods and Materials: Mice bearing B16-OVA murine melanoma were treated with up to 15 Gy radiation given in various-size fractions, and tumor growth followed. The tumor-specific immune response in the spleen was assessed by interferon-{gamma} enzyme-linked immunospot (ELISPOT) assay with ovalbumin (OVA) as the surrogate tumor antigen and the contribution of regulatory T cells (Tregs) determined by the proportion of CD4{sup +}CD25{sup hi}Foxp3{sup +} T cells. Results: After single doses, tumor control increased with the size of radiation dose, as did the number of tumor-reactive T cells. This was offset at the highest dose by an increase in Treg representation. Fractionated treatment with medium-size radiation doses of 7.5 Gy/fraction gave the best tumor control and tumor immunity while maintaining low Treg numbers. Conclusions: Radiation can be an immune adjuvant, but the response varies with the size of dose per fraction. The ultimate challenge is to optimally integrate cancer immunotherapy into radiation therapy.

Schaue, Doerthe, E-mail: dschaue@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ratikan, Josephine A.; Iwamoto, Keisuke S.; McBride, William H. [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States)

2012-07-15T23:59:59.000Z

250

The Status of Normal Conducting RF (NCRF) Guns, a Summary of the ERL2005 Workshop  

Science Conference Proceedings (OSTI)

The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20 to 23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrated upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

Dowell, D.H.; /SLAC; Lewellen, J.W.; /Argonne; Nguyen, D.; /Los Alamos; Rimmer, R.; /Jefferson Lab

2006-03-13T23:59:59.000Z

251

The status of normal conducting RF (NCRF) guns; a summary of the ERL2005 Workshop  

SciTech Connect

The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20 to 23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrated upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

D.H. Dowell; J.W. Lewellen; D. Nguyen; R.A. Rimmer

2005-03-19T23:59:59.000Z

252

DESIGN CONSIDERATIONS FOR LOW FIELD SHORT PHOTO-INJECTED RF ELECTRON GUN WITH HIGH CHARGE ELECTRON BUNCH.  

Science Conference Proceedings (OSTI)

The RF field and space charge effect in a low field RF gun is given. The cell lengths are modified to have maximum accelerating efficiency. The modification introduces an extra RF field slice emittance. The phase space evolution of the following emittance compensation system is presented taking into account the chromatic effect. The emittance compensation mechanics for RF field and chromatic effect induced emittance is similar to that of compensating the space charge induced emittance. But the requirements are different to have best compensation for them. The beam waist is far in front of linac entrance to have best compensation for the RF field and chromatic effect induced emittance. For low field RF gun with high charge electron bunch this compensation is more important.

CHANG,X.; BEN-ZVI,I.; KEWISCH,J.

2004-06-21T23:59:59.000Z

253

Throughput and delay analysis for hybrid radio-frequency and free-space-optical (RF/FSO) networks  

Science Conference Proceedings (OSTI)

In this paper the per-node throughput and end-to-end delay of randomly deployed (i.e. ad-hoc) hybrid radio frequency - free space optics (RF/FSO) networks are studied. The hybrid RF/FSO network consists of an RF ad hoc network of n nodes, f(n) ... Keywords: Ad hoc networks, Delay, Free space optics, Hybrid networks, Throughput capacity

Di Wang; Alhussein A. Abouzeid

2011-05-01T23:59:59.000Z

254

On sampling fractions and electron shower shapes  

SciTech Connect

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

255

An Efficient Supply Modulator for Linear Wideband RF Power Amplifiers  

E-Print Network (OSTI)

Radio Frequency (RF) Power Amplifiers are responsible for a considerable amount of the power consumption in the entire transmitter-receiver (transceiver) of modern communication systems. The stringent linearity requirements of multi-standard transceivers to minimize cross-talking effects makes Linear Power Amplifiers, particularly class A, the preferred choice in broadband transceivers. This linearity requirement coupled with the fact that the Power Amplifier operates at low transmit power during most of its operation makes the efficiency of the entire transceiver poor. The limited transceiver efficiency leads to a reduction in the battery life of battery operated portable devices like mobile phones; hence drastically limiting talk time. To alleviate this issue, several research groups propose solutions to improve PA power efficiency. However, these solutions usually have a low efficiency at low power and are mostly limited to narrow bandwidth applications. In this thesis, the efficiency of a class A Power amplifier in wideband wireless standards like WiMax is improved by dynamically controlling the bias current and supply voltage of the PA. An efficient supply modulator based on a switching regulator architecture is proposed for controlling the supply voltage. The switching regulator is found to be slew-limited by the bulky inductor and capacitor used to regulate the supply voltage. The proposed solution alleviates the slew rate limitation by adding a bang-bang controlled current source. The proposed supply modulator has an average power efficiency of 81.6 percent and is suitable for wireless standards with bandwidths up to 20MHz compared to the relatively lower efficiencies and bandwidths of state of the art modulators. A class-A PA is shown to promise an average power efficiency of 21.3 percent when the bias current is controlled dynamically and the supply voltage is varied using the proposed supply modulator. This is a significant improvement over the poor average efficiency of 1.06 percent for a fixed bias conventional linear class A PA. The project has been simulated using the TSMC 0.18 micrometer technology.

Turkson, Richard

2011-08-01T23:59:59.000Z

256

rf improvements for Spallation Neutron Source H{sup -} ion source  

SciTech Connect

The Spallation Neutron Source at Oak Ridge National Laboratory is ramping up the accelerated proton beam power to 1.4 MW and just reached 1 MW. The rf-driven multicusp ion source that originates from the Lawrence Berkeley National Laboratory has been delivering {approx}38 mA H{sup -} beam in the linac at 60 Hz, 0.9 ms. To improve availability, a rf-driven external antenna multicusp ion source with a water-cooled ceramic aluminum nitride (AlN) plasma chamber is developed. Computer modeling and simulations have been made to analyze and optimize the rf performance of the new ion source. Operational statistics and test runs with up to 56 mA medium energy beam transport beam current identify the 2 MHz rf system as a limiting factor in the system availability and beam production. Plasma ignition system is under development by using a separate 13 MHz system. To improve the availability of the rf power system with easier maintenance, we tested a 70 kV isolation transformer for the 80 kW, 6% duty cycle 2 MHz amplifier to power the ion source from a grounded solid-state amplifier.

Kang, Y. W.; Fuja, R.; Hardek, T.; Lee, S.-W.; McCarthy, M. P.; Piller, M. C.; Shin, K.; Stockli, M. P.; Welton, R. F. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Goulding, R. H. [Fusion Energy Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2010-02-15T23:59:59.000Z

257

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

Science Conference Proceedings (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

258

A SUMMARY OF TEST OBSERVATIONS WHEN IBUTTONS ARE SUBJECTED TO RF ENERGY  

SciTech Connect

The iButton is a 'one-wire', temperature sensor and data logger in a short metal cylinder package 17 mm in diameter and 6 mm tall. The device is designed to be attached to a surface and acquire temperature samples over time periods as short as 1 second to as long as 300 minutes. Both 8-bit and 16-bit samples are available with 8kB of memory available. Lifetime is limited to an internal battery that cannot be replaced or recharged. The RF test interest originated with the concern that the data logger could inadvertently record electrical emanations from other nearby equipment. The normal operation of the data logger does not support high speed sampling but the control interface will operate at either 15.4 kbps or 125 kbps. There were no observable effects in the operation of the module or in the data that could be attributed to the use of RF energy. They made the assumption that these devices would potentially show RF sensitivity in any of the registers and in the data memory equally, therefore gross changes in the data might show RF susceptibility. No such sensitivity was observed. Because significant power levels were used for these tests they can extrapolate downward in power to state that no RF susceptibility would occur at lower power levels given the same configurations.

Kane, R J; Baluyot, E V

2011-10-26T23:59:59.000Z

259

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.

Woods, Paul M

2008-01-01T23:59:59.000Z

260

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

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261

Simulations of RF capture with barrier bucket in booster at injection  

Science Conference Proceedings (OSTI)

As part of the effort to increase the number of ions per bunch in RHIC, a new scheme for RF capture of EBIS ions in Booster at injection has been developed. The scheme was proposed by M. Blaskiewicz and J.M. Brennan. It employs a barrier bucket to hold a half turn of beam in place during capture into two adjacent harmonic 4 buckets. After acceleration, this allows for 8 transfers of 2 bunches from Booster into 16 buckets on the AGS injection porch. During the Fall of 2011 the necessary hardware was developed and implemented by the RF and Controls groups. The scheme is presently being commissioned by K.L. Zeno with Au32+ ions from EBIS. In this note we carry out simulations of the RF capture. These are meant to serve as benchmarks for what can be achieved in practice. They also allow for an estimate of the longitudinal emittance of the bunches on the AGS injection porch.

Gardner, C.J.

2012-01-23T23:59:59.000Z

262

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

263

Parasitic Effects Reduction for Wafer-Level Packaging of RF-Mems  

E-Print Network (OSTI)

In RF-MEMS packaging, next to the protection of movable structures, optimization of package electrical performance plays a very important role. In this work, a wafer-level packaging process has been investigated and optimized in order to minimize electrical parasitic effects. The RF-MEMS package concept used is based on a wafer-level bonding of a capping silicon substrate to an RF-MEMS wafer. The capping silicon substrate resistivity, substrate thickness and the geometry of through-substrate electrical interconnect vias have been optimized using finite-element electromagnetic simulations (Ansoft HFSS). Test structures for electrical characterization have been designed and after their fabrication, measurement results will be compared with simulations.

Iannacci, J; Sinaga, S; Gaddi, R; Gnudi, A; Bartek, M

2007-01-01T23:59:59.000Z

264

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

SciTech Connect

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

265

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

266

Void fraction instrument acceptance test procedure  

DOE Green Energy (OSTI)

This acceptance test procedure (ATP) was written to test the void fraction instrument (VFI) and verify that the unit is ready for field service. The procedure verifies that the mechanical and electrical features (not specifically addressed in the software ATP) and software alarms are operating as designed.

Pearce, K.L.

1994-09-15T23:59:59.000Z

267

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

SciTech Connect

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

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

2013-12-01T23:59:59.000Z

268

Mini RF-driven ion source for focused ion beam system  

DOE Green Energy (OSTI)

Mini RF-driven ion sources with 1.2 cm and 1.5 cm inner chamber diameter have been developed at Lawrence Berkeley National Laboratory. Several gas species have been tested including argon, krypton and hydrogen. These mini ion sources operate in inductively coupled mode and are capable of generating high current density ion beams at tens of watts. Since the plasma potential is relatively low in the plasma chamber, these mini ion sources can function reliably without any perceptible sputtering damage. The mini RF-driven ion sources will be combined with electrostatic focusing columns, and are capable of producing nano focused ion beams for micro machining and semiconductor fabrications.

Jiang, X.; Ji, Q.; Chang, A.; Leung, K.N.

2002-08-02T23:59:59.000Z

269

High power tests of dressed supconducting 1.3 GHz RF cavities  

SciTech Connect

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

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

2011-03-01T23:59:59.000Z

270

Simulation and analysis of rf feedback systems on the SLC damping rings  

SciTech Connect

The rf system of the SLC Damping Rings has evolved since tighter tolerances on beam stability are encountered as beam intensities are increased. There are now many feedback systems controlling the phase and amplitude of the rf, the phase of the beam, and the tune of the cavity. The bandwidths of the feedback loops range from several MHz to compensate for beam loading to a few Hz for the cavity tuners. To improve our understanding of the interaction of these loops and verify the expected behavior, we have simulated their behavior using computer models. A description of the models and the first results are discussed.

Minty, M.; Himel, T.; Krejcik, P.; Siemann, R.H.; Tighe, R.

1993-09-01T23:59:59.000Z

271

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

272

RF System Upgrades to the Advanced Photon Source Linear Accelerator in Support of the Fel Operation  

E-Print Network (OSTI)

The S-band linear accelerator, which was built to be the source of particles and the front end of the Advanced Photon Source injector, is now also being used to support a low-energy undulator test line (LEUTL) and to drive a free-electron laser (FEL). The more severe rf stability requirements of the FEL have resulted in an effort to identify sources of phase and amplitude instability and implement corresponding upgrades to the rf generation chain and the measurement system. Test data and improvements implemented and planned are described

Smith, T L; Grelick, A E; Pile, G; Nassiri, A; Arnold, N

2000-01-01T23:59:59.000Z

273

Coherent Spin Manipulations of a Polarized Beam With a Localized RF Magnetic Field  

E-Print Network (OSTI)

The coherent manipulation of spin observables in storage rings provides opportunities to test the application of some fundamental dynamical principles. In this context, it is possible to confirm, using gauge invariance and Lorentz invariance, a conjecture framed by A. M. Kondratenko concerning the "natural" or "intrinsic" resonance strength applicable to a spin rotation from a controlled Froissart-Stora sweep with an RF dipole magnet. The discussion includes a brief treatment of the "forced" component of the resonance strength associated with the effect of the betatron oscillations induced by the operation of the RF diple and a discussion of the effective resonance strength as a function of betatron tunes.

Dennis Sivers

2007-10-12T23:59:59.000Z

274

Low temperature rf sputtering deposition of (Ba, Sr) TiO{sub 3} thin film with crystallization enhancement by rf power supplied to the substrate  

SciTech Connect

The (Ba, Sr) TiO{sub 3} thin film deposited by radio frequency (rf) sputtering requires a high deposition temperature near 500 deg. C to realize a high relative dielectric constant over of 300. For example, the film deposited at 330 deg. C contains an amorphous phase and shows a low relative dielectric constant of less than 100. We found that rf power supplied not only to the (Ba, Sr) TiO{sub 3} sputtering target, but also to the substrate during the initial step of film deposition, enhanced the crystallization of the (Ba, Sr) TiO{sub 3} film drastically and realized a high dielectric constant of the film even at low deposition temperatures near 300 deg. C. The 50-nm-thick film with only a 10 nm initial layer deposited with the substrate rf biasing is crystallized completely and shows a high relative dielectric constant of 380 at the deposition temperature of 330 deg. C. The (Ba, Sr) TiO{sub 3} film deposited at higher temperatures (upwards of 400 deg. C) shows <110> preferred orientation, while the film deposited at 330 deg. C with the 10 nm initial layer shows a <111> preferred orientation on a <001>-oriented ruthenium electrode. The unit cell of (Ba, Sr) TiO{sub 3} (111) plane is similar to that of ruthenium (001) plane. We conclude that the rf power supplied to the substrate causes ion bombardments on the (Ba, Sr) TiO{sub 3} film surface, which assists the quasiepitaxial growth of (Ba, Sr) TiO{sub 3} film on the ruthenium electrode at low temperatures of less than 400 deg. C.

Yoshimaru, Masaki; Takehiro, Shinobu; Abe, Kazuhide; Onoda, Hiroshi [System LSI Research Division, Silicon Solution Company, Oki Electric Industry Co., Ltd., 550-1, Higashi-asakawa, Hachioji, Tokyo 193-8550 (Japan); Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Strategic Planning Office, Silicon Manufacturing Company, Oki Electric Industry Co., Ltd., 550-1, Higashi-asakawa, Hachioji, Tokyo 193-8550 (Japan)

2005-05-01T23:59:59.000Z

275

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

276

Low temperature high density Si3N4 MIM capacitor technology for MMMIC and RF-MEMs applications  

Science Conference Proceedings (OSTI)

In this work, a novel, high quality, high-density, deposited at room temperature ultra thin 5 nm Si3N4 metal insulator metal (MIM) capacitor process for monolithic millimetre-wave integrated circuit (MMMIC) applications ... Keywords: RF MEMs, RF MIM capacitors, dielectric films, high density capacitors, room temperature ultra thin silicon nitride films metal insulator metal capacitors

K. Elgaid; H. Zhou; C. D. W. Wilkinson; I. G. Thayne

2004-06-01T23:59:59.000Z

277

Fourier Spectrum-Based Signature Test: A Genetic CAD Toolbox for Reliable RF Testing Using Low-Performance Test Resources  

Science Conference Proceedings (OSTI)

At the present time, coordinated EDA tools for RF/mixed-signal pin test do not exist. In this paper, a CAD tool for efficient production testing of highperformance RF systems using low-cost baseband ATE is presented. The CAD tool consists of a custom ...

G. Srinivasan; A. Chatterjee

2007-10-01T23:59:59.000Z

278

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 55, NO. 10, OCTOBER 2007 2043 Power Supply Rejection for RF Amplifiers  

E-Print Network (OSTI)

from noise or voltage ripple on the power supply. As demonstrated in Fig. 1, spectral energy injected the interaction of supply noise with RF amplifier components for successful design of the system. In the context noted, the op- erator is not fully symmetric in this representation because the supply noise and RF

Sanders, Seth

279

814 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 50, NO. 3, MARCH 2002 Power Amplifiers and Transmitters for RF  

E-Print Network (OSTI)

resistances. The 1990s saw a proliferation of a variety of new solid-state devices including HEMT, pHEMT, HFET, linearity, and cost. RF power is generated by a wide variety of techniques, implementations, and active of generating and controlling RF signals, and vacuum-tube PAs were dominant from the late 1920s through the mid

Popovic, Zoya

280

A Lyapunov approach to the stability of fractional differential equations  

Science Conference Proceedings (OSTI)

Lyapunov stability of fractional differential equations is addressed in this paper. The key concept is the frequency distributed fractional integrator model, which is the basis for a global state space model of FDEs. Two approaches are presented: the ... Keywords: Fractional differential equations, Fractional integrator, Lyapunov stability, Nonlinear FDEs, State space models

J. C. Trigeassou; N. Maamri; J. Sabatier; A. Oustaloup

2011-03-01T23:59:59.000Z

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.


281

Global attractors for parabolic problems in fractional power spaces  

Science Conference Proceedings (OSTI)

Keywords: cooperative systems, fractional power spaces, global attractors, reaction-diffusion equations, thin domains

Alexandre Nolasco De Carvalho; José Gaspar Ruas-Filho

1995-03-01T23:59:59.000Z

282

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

283

Clean Fractionation: Technology Available for Licensing  

NLE Websites -- All DOE Office Websites (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

284

Methods And Apparatus For Acoustic Fiber Fractionation  

DOE Patents (OSTI)

Methods and apparatus for acoustic fiber fractionation using a plane ultrasonic wave field interacting with water suspended fibers circulating in a channel flow using acoustic radiation forces to separate fibers into two or more fractions based on fiber radius, with applications of the separation concept in the pulp and paper industry. The continuous process relies on the use of a wall-mounted, rectangular cross-section piezoelectric ceramic transducer to selectively deflect flowing fibers as they penetrate the ultrasonic field. The described embodiment uses a transducer frequency of approximately 150 kHz. Depending upon the amount of dissolved gas in water, separation is obtained using a standing or a traveling wave field.

Brodeur, Pierre (Smyrna, GA)

1999-11-09T23:59:59.000Z

285

AHP gives NGL fractionation energy savings  

SciTech Connect

Absorption heat pumping (AHP) offers a highly economic and widely applicable avenue to process heat integration and heat recovery in natural gas liquid (NGL) fractionation plants. Economically priced equipment is now available for any required capacity rating. Installations are increasing. In conventional heat pumping, heat at a low temperature is supplied to an evaporator, causing a liquid to boil at low pressure. This low pressure vapor is compressed. The high pressure vapor condenses, giving up latent heat at a high temperature. The difference between the heat supply temperature and heat delivery temperature is the ''lift'' furnished by the heat pump. Existing NGL fractionation plants offer highly economic opportunities for retrofit AHP applications. Designers of new plants can exploit AHP technology to further economic advantage.

Davidson, W.F.; Erickson, D.C.

1985-08-05T23:59:59.000Z

286

Radiotherapy Dose Fractionation under Parameter Uncertainty  

SciTech Connect

In radiotherapy, radiation is directed to damage a tumor while avoiding surrounding healthy tissue. Tradeoffs ensue because dose cannot be exactly shaped to the tumor. It is particularly important to ensure that sensitive biological structures near the tumor are not damaged more than a certain amount. Biological tissue is known to have a nonlinear response to incident radiation. The linear quadratic dose response model, which requires the specification of two clinically and experimentally observed response coefficients, is commonly used to model this effect. This model yields an optimization problem giving two different types of optimal dose sequences (fractionation schedules). Which fractionation schedule is preferred depends on the response coefficients. These coefficients are uncertainly known and may differ from patient to patient. Because of this not only the expected outcomes but also the uncertainty around these outcomes are important, and it might not be prudent to select the strategy with the best expected outcome.

Davison, Matt [Department of Applied Mathematics, University of Western Ontario, London, Ontario (Canada); Department of Statistical and Actuarial Science, University of Western Ontario, London, Ontario (Canada); Ivey School of Business, University of Western Ontario, London, Ontario (Canada); Kim, Daero [Department of Applied Mathematics, University of Western Ontario, London, Ontario (Canada); Keller, Harald [Department Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada)

2011-11-30T23:59:59.000Z

287

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

SciTech Connect

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

288

Pyrolysis of shale oil residual fractions  

SciTech Connect

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

289

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

290

Conservation Biology (Biology 45300) An Ecology Course for the Fall of 2007 with RF Rockwell  

E-Print Network (OSTI)

Conservation Biology (Biology 45300) An Ecology Course for the Fall of 2007 with RF Rockwell Biology 45300 - Conservation Biology This undergraduate course provides an introduction to conservation biology with an emphasis on the interplay of various fields of biology in the mamangement and conservation

Lombardi, John R.

291

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC  

E-Print Network (OSTI)

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC S. Schreiber for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract During 1997 and 1998 a first accelerator module was tested successfully at the TESLA Test Facility Linac (TTFL) at DESY. Eight superconducting

292

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 the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract The TESLA Test Facility Linac (TTFL) at DESY uses two modules with 8 TESLA superconducting accelerat- ing structures each to accelerate an electron

293

Optical Investigations of Dust Particles Distribution in RF and DC Discharges  

Science Conference Proceedings (OSTI)

Optical emission spectroscopy is used to study dust particles movement and conditions of a formation of ordered plasma-dust structures in a capacitively coupled RF discharge. 3D binocular diagnostics of plasma-dust structures in dc discharge was made.

Ramazanov, T. S.; Dosbolayev, M. K.; Jumabekov, A. N.; Amangaliyeva, R. Zh. [Al-Farabi Kazakh National University, IETP, 96a Tole Bi St., Almaty 050012 (Kazakhstan); Filatova, I. I.; Azharonok, V. V. [B. I. Stepanov Institute of Physics NAS of Belarus, Nezavisimosti Ave., 68, 220072, Minsk (Belarus)

2008-09-07T23:59:59.000Z

294

RF undulator for compact X-ray SASE source of variable wavelength  

Science Conference Proceedings (OSTI)

A room-temperature RF undulator, fed by Ka-band radiation and intended to produce {approx}1 nm wavelength radiation using moderate energy electrons, is considered. The necessary electron bunches with energy 0.2-1 GeV could be produced by petawatt laser pulses injected into plasma bubbles.

Kuzikov, S. V.; Hirshfield, J. L.; Jiang, Y.; Marshall, T. C.; Vikharev, A. A. [Institute of Applied Physics, 46 Ulyanov St., Nizhny Novgorod, 603950 (Russian Federation) and Omega-P, Inc., New Haven, CT (United States); Yale University, New Haven, CT (United States) and Omega-P, Inc., New Haven, CT (United States); Yale University, New Haven, CT (United States); Omega-P, Inc., New Haven, CT (United States) and Columbia University, New York, NY (United States); Yale University, New Haven, CT (United States)

2012-12-21T23:59:59.000Z

295

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

SciTech Connect

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

296

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

DOE Green Energy (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

297

The design of a high efficiency RF power amplifier for an MCM process  

E-Print Network (OSTI)

In this thesis, I addressed issues arising in the design of a high efficiency RF power amplifier for the Draper Laboratory multi-chip module (MCM) process. A design for a 2.3 GHz PCB amplifier using an enhancement-mode ...

Noonan, James (James Keating)

2005-01-01T23:59:59.000Z

298

New high power 200 MHz RF system for the LANSCE drift tube linac  

SciTech Connect

The Los Alamos Neutron Science Center (LANSCE) linac provides an 800 MeV direct H{sup +} proton beam, and injects H{sup {minus}} to the upgraded proton storage ring for charge accumulation for the Short Pulse Spallation Source. Accelerating these interlaced beams requires high average power from the 201.25 MHz drift tube linac (DTL) RF system. Three power amplifiers have operated at up to three Megawatts with 12% duty factor. The total number of electron power tubes in the RF amplifiers and their modulators has been reduced from fifty-two to twenty-four. The plant continues to utilize the original design of a tetrode driving a super power triode. Further increases in the linac duty factor are limited, in part, by the maximum dissipation ratings of the triodes. A description of the system modifications proposed to overcome these limitations includes new power amplifiers using low-level RF modulation for tank field control. The first high power Diacrode{reg_sign} is being delivered and a new amplifier cavity is being designed. With only eight power tubes, the new system will deliver both peak power and high duty factor, with lower mains power and cooling requirements. The remaining components needed for the new RF system will be discussed.

Lyles, J.; Friedrichs, C.; Lynch, M.

1998-12-31T23:59:59.000Z

299

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-Print Network (OSTI)

An investigation of the sympathetic cooling method for the studies of large ultra-cold molecular ions in a quadrupole ion trap has been conducted.Molecular dynamics simulations are performed to study the rf heating mechanisms in the ion trap. The dependence of rf heating rates on the ion temperature, trapping parameters, and the number of ions is obtained. New rf heating mechanism affecting ultra-cold ion clouds exposed to laser radiation is described.The saturation spectroscopy setup of the hyperfine spectra of the molecular iodine has been built to provide an accurate frequency reference for the laser wavelength. This reference is used to obtain the fluorescence lineshapes of the laser cooled Mg$^+$ ions under different trapping conditions.The ion temperatures are deduced from the measurements, and the influence of the rf heating rates on the fluorescence lineshapes is also discussed. Cooling of the heavy ($m=720$a.u.) fullerene ions to under 10K by the means of the sympathetic cooling by the Mg$^+$ ions($m=24$a.u.) is demonstrated. The single-photon imaging system has been developed and used to obtain the images of the Mg$^+$ ion crystal structures at mK temperatures.

Ryjkov, Vladimir Leonidovich

2003-12-01T23:59:59.000Z

300

Mitigating the effects of RF interference through RSSI-Based error recovery  

Science Conference Proceedings (OSTI)

On a common sensor node platform (Telos) we sample RSSI with high frequency during packet reception. We find that a packet collision (RF interference) often manifests as a measurable, temporal increase in RSSI. We investigate how the receiver ... Keywords: ARQ, interference mitigation, packet combining

Jan-Hinrich Hauer; Andreas Willig; Adam Wolisz

2010-02-01T23:59:59.000Z

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

Performance evaluation of indoor localization techniques based on RF power measurements from active or passive devices  

Science Conference Proceedings (OSTI)

The performance of networks for indoor localization based on RF power measurements from active or passive devices is evaluated in terms of the accuracy, complexity, and costs. In the active device case, the terminal to be located measures the power transmitted ...

Damiano De Luca; Franco Mazzenga; Cristiano Monti; Marco Vari

2006-01-01T23:59:59.000Z

302

RF Couplers for Normal-Conducting Photoinjector of High-Power CW FEL  

E-Print Network (OSTI)

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by "dog-bone" irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

Kurennoy, Sergey; Wood, Richard L; Schultheiss, T J; Rathke, John; Young, Lloyd

2004-01-01T23:59:59.000Z

303

RF Distribution System for High Power Test of the SNS Cryomodule  

Science Conference Proceedings (OSTI)

A four-way waveguide RF power distribution system for testing the Spallation Neutron Source (SNS) multi-cavity cryomodule to investigate the collective behavior has been developed. A single klystron operating at 805MHz for 1.3 msec at 60Hz powers the 4-way waveguide splitter to deliver up to 400 kW to individual cavities. Each cavity is fed through a combination of waveguide splitters and vector modulators (VM) to provide independent magnitude and phase controls. The waveguide vector modulator consists of two quadrature hybrids and two motorized waveguide phase shifters. The phase shifters and the assembled waveguide vector modulators were individually tested and characterized for low power and high RF power in the SNS RF test facility. Precise calibrations of magnitude and phase were performed to generate the look up tables (LUTs) to provide operational references during the cryomodule test. An I-Q demodulator module was developed and utilized to measure relative phases in pulsed high RF power operation. PLC units were developed for mechanical control of the phase shifters. Initial low/high power measurements were made using LabVIEW. An operation algorithm has been implemented into EPICS control for the cryomodule test stand.

Lee, Sung-Woo [ORNL; Kang, Yoon W [ORNL; Broyles, Michael R [ORNL; Crofford, Mark T [ORNL; Geng, Xiaosong [ORNL; Kim, Sang-Ho [ORNL; Phibbs, Curtis L [ORNL; Strong, William Herb [ORNL; Peglow, Robert C [ORNL; Vassioutchenko, Alexandre V [ORNL

2012-01-01T23:59:59.000Z

304

RF couplers for normal-conducting photoinjector of high-power CW FEL  

SciTech Connect

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz bunch repetition rate) to 2.7 MeV while providing an emittance below 7 mm-mrad at the wiggler. More than 1 MW of RF power will be fed into the photoinjector cavity through two ridge-loaded tapered waveguides. The waveguides are coupled to the cavity by 'dog-bone' irises cut in a thick wall. Due to CW operation of the photoinjector, the cooling of the coupler irises is a rather challenging thermal management project. This paper presents results of a detailed electromagnetic modeling of the coupler-cavity system, which has been performed to select the coupler design that minimizes the iris heating due to RF power loss in its walls.

Kurennoy, S. (Sergey)

2004-01-01T23:59:59.000Z

305

Low emittance electron beam production and characterization with a 17 GHz photocathode RF gun  

E-Print Network (OSTI)

This thesis presents theoretical and experimental results of the production of very high brightness electron beams using a 17 GHz photocathode RF gun. A beam brightness of up to 8x 1013 A/([pi]m rad)2 was measured for a 1 ...

Brown, Winthrop Joseph

2001-01-01T23:59:59.000Z

306

Solutions of the Fractional Reaction Equation and the Fractional Diffusion Equation  

E-Print Network (OSTI)

In view of the role of reaction equations in physical problems, the authors derive the explicit solution of a fractional reaction equation of general character, that unifies and extends earlier results. Further, an alternative shorter method based on a result developed by the authors is given to derive the solution of a fractional diffusion equation. Fox functions and Mittag-Leffler functions are used for closed-form representations of the solutions of the respective differential equations.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2010-01-13T23:59:59.000Z

307

Iron isotopic fractionation during continental weathering  

SciTech Connect

The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01T23:59:59.000Z

308

Measurement of tau lepton branching fractions  

SciTech Connect

We present {tau}{sup {minus}} lepton branching fraction measurements based on data from the TPC/Two-Gamma detector at PEP. Using a sample of{tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} events, we examine the resonance structure of the K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} system and obtain the first measurements of branching fractions for {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1270) and {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1400). We also describe a complete set of branching fraction measurements in which all the decays of the {tau}{sup {minus}} lepton are separated into classes defined by the identities of the charged particles and an estimate of the number of neutrals. This is the first such global measurement with decay classes defined by the four possible charged particle species, e, {mu}, {pi}, and K.

Nicol, N.A.

1993-09-30T23:59:59.000Z

309

Pyruvate and Lactate Metabolism by Shewanella oneidensis MR-1 under Fermentation, Oxygen Limitation, and Fumarate Respiration Conditions  

Science Conference Proceedings (OSTI)

Shewanella oneidensis MR-1 is a facultative anaerobe that derives energy by coupling organic matter oxidation to the reduction of wide range of electron acceptors. Here, we quantitatively assessed lactate and pyruvate metabolism of MR-1 under three distinct conditions: electron acceptor limited growth on lactate with O2; lactate with fumarate; and pyruvate fermentation. The latter does not support growth but provides energy for cell survival. Using physiological and genetic approaches combined with flux balance analysis, we showed that the proportion of ATP produced by substrate-level phosphorylation varied from 33% to 72.5% of that needed for growth depending on the electron acceptor nature and availability. While being indispensible for growth, respiration of fumarate does not contribute significantly to ATP generation and likely serves to remove formate, a product of pyruvate formate-lyase-catalyzed pyruvate disproportionation. Under both tested respiratory conditions S. oneidensis MR-1 carried out incomplete substrate oxidation, whereby the TCA cycle did not contribute significantly. Pyruvate dehydrogenase was not involved in lactate metabolism under O2 limitation but was required for anaerobic growth likely by supplying reducing equivalents for biosynthesis. The results suggest that pyruvate fermentation by S. oneidensis MR-1 cells represents a combination of substrate-level phosphorylation and respiration, where pyruvate serves as electron donor and electron acceptor. Pyruvate reduction to lactate at the expense of formate oxidation is catalyzed by recently described new type of oxidative NAD(P)H independent D-lactate dehydrogenase (Dld-II). The results further indicate that pyruvate reduction coupled to formate oxidation may be accompanied by proton motive force generation.

Pinchuk, Grigoriy E.; Geydebrekht, Oleg V.; Hill, Eric A.; Reed, Jennifer L.; Konopka, Allan; Beliaev, Alex S.; Fredrickson, Jim K.

2011-12-01T23:59:59.000Z

310

Report on the Best Available Technology (BAT) for the treatment of the INEL Central Laundry and Respirator Facility (CFA-617)  

SciTech Connect

The Central Laundry and Respirator Facility (CLRF) designated by the building number of CFA-617 has been addressed as a potential source of contamination to the Central Facilities Area (CFA) subsurface drainage field which also receives waste water from the current CFA Sewage Treatment Plant (STP). Currently, discharges from the CLRF have been below set guidelines, DCG. A new STP has been proposed for the CFA. Since the CLRF has been designated as a potential source of contamination, a Best Available Technology (BAT) assessment was requested to determine what action should be taken in respect to the aqueous discharges from the CLRF. The BAT assessment involved source definition, technology evaluation, BAT matrix development, BAT selection, and BAT documentation. The BAT for the Central laundry and Respirator Facility selected the treatment which would impact the CLRF and the new STP the least in all aspects considered and was the system of filtration and a lined pond for natural evaporation of the water. The system will provide an isolation of this waste stream from all other CFA waste water which will be treated at the new STP. Waste minimization possibilities exist within the laundry process and are considered. These minimization actions will reduce the amount of waste water being released, but will result in raising the contaminate's concentrations (the total mass will remain the same). The second option was the use of ion exchange to remove the contaminates and recycle the water back to the wash and rinse cycles in the laundry. 3 refs., 9 figs., 11 tabs.

Miyasaki, D.H.; Heiser, D.L.

1991-01-01T23:59:59.000Z

311

Using a Bayesian framework and global sensitivity analysis to identify strengths and weaknesses of two process-based models differing in representation of autotrophic respiration  

Science Conference Proceedings (OSTI)

Process-based models are powerful tools for sustainable and adaptive forest management. Bayesian statistics and global sensitivity analysis allow to reduce uncertainties in parameters and outputs, and they provide better insight of model behaviour. In ... Keywords: 3-PG, Bayesian calibration, Bayesian model comparison, Carbon cycle, Global sensitivity analysis, Morris screening, Net primary production, Respiration, Uncertainty analysis

F. Minunno; M. Van Oijen; D. R. Cameron; S. Cerasoli; J. S. Pereira; M. Tomé

2013-04-01T23:59:59.000Z

312

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

SciTech Connect

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

313

High power testing of the 402.5 MHZ and 805 MHZ RF windows for the spallation neutron source accelerator  

SciTech Connect

Hisorically, Radio Frequency (RF) windows have been a common point of failure in input power couplers; therefore, reliable RF windows are critical to the success of the Spallation Neutron Source (SNS) project. The normal conducting part of the SNS accelerator requires six RF windows at 402.5 MHz and eight RF windows at 805 MHz[l]. Each RF window will transmit up to 180 kW of average power and 2.5 MW peak power at 60 Hz with 1.2 millisecond pulses. The RF windows, designed and manufactured by Thales, were tested at the full average power for 4 hours to ensure no problems with the high average power and then tested to an effective forward power level of 10 MW by testing at 2.5 MW forward power into a short and varying the phase of the standing wave. The sliding short was moved from 0 to 180 degrees to ensure no arcing or breakdown problems occur in any part of the window. This paper discusses the results of the high power testing of both the 402.5 MHz and the 805 MHz RF windows. Problems encountered during testing and the solutions for these problems are discussed.

Cummings, K. A. (Karen Ann); De Baca, J. M. (John M.); Harrison, J. S. (John S.); Rodriguez, M. B. (Manuelita B.); Torrez, P. A. (Phillip A.); Warner, D. K. (David K.)

2003-01-01T23:59:59.000Z

314

RF Design and Operating Performance of the BNL/AES 1.3 GHz Single Cell Superconducting RF Photocathode Electron Gun  

SciTech Connect

Over the past several years Advanced Energy Systems and BNL have been collaborating on the development and testing of a fully superconducting photocathode electron gun. Over the past year we have begun to realize significant results which have been published elsewhere [1]. This paper will review the RF design of the gun under test and present results of its performance under various operating conditions. Results for cavity quality factor will be presented for various operating temperatures and cavity field gradients. We will also discuss future plans for testing using this gun.

Cole, Michael; Kneisel, Peter; Ben-Zvi, Ilan; Burrill, Andrew; Hahn, H.; Rao, Triveni; Zhao, Y.

2005-05-01T23:59:59.000Z

315

RF DESIGN AND OPERATING PERFORMANCE OF THE BNL/AES 1.3 GHZ SINGLE CELL SUPERCONDUCTING RF PHOTOCATHODE ELECTRON GUN.  

Science Conference Proceedings (OSTI)

Over the past several years Advanced Energy Systems and BNL have been collaborating on the development and testing of a fully superconducting photocathode electron gun. Over the past year we have begun to realize significant results which have been published elsewhere [1]. This paper will review the RF design of the gun under test and present results of its performance under various operating conditions. Results for cavity quality factor will be presented for various operating temperatures and cavity field gradients. We will also discuss future plans for testing using this gun.

COLE, M.; KNEISEL, P.; BEN-ZVI, I.; BURRILL, A.; HAHN, G.; RAO, T.; ZHAO, Y.

2005-05-16T23:59:59.000Z

316

Optimizing injected solvent fraction in stratified reservoirs  

E-Print Network (OSTI)

Waterflooding has become standard practice for extending the productive life of many solution gas drive reservoirs, but has the disadvantage of leaving a substantial residual oil volume in the reservoir. Solvent flooding has been offered as a method whereby oil may be completely displaced from the reservoir, leaving no residual volume. Field results have demonstrated that solvent floods suffer from early solvent breakthrough and considerable oil by-passing owing to high solvent mobility. The injection of both water and solvent has been demonstrated to offer advantages. Water partially mitigates both the adverse mobility and high cost of solvent floods, while solvent mobilizes oil which would be left in the reservoir by water alone. The process is equally applicable to reservoirs currently at residual oil saturation (tertiary floods) and to reservoirs at maximum oil saturation (secondary floods). In stratified reservoirs high permeability layers may be preferentially swept by solvent floods, while low permeability layers may be scarcely swept at all. Presence or absence of transverse communication between layers can modify overall sweep efficiency. This work is a study of water-solvent injection in stratified reservoirs based on computer simulation results. Fractional oil recovery as a function of injected solvent fraction, permeability contrast between layers, initial oil saturation, and presence or absence of transverse communication between strata has been determined. Results are presented as a series of optimization curves. Permeability contrast between layers is shown to be the dominant control on fractional oil recovery. Transverse communicating reservoirs are shown to require a higher solvent-water ratio in order to attain recoveries comparable to transverse noncommunicating reservoirs. In actual field projects, water and solvent are injected alternately as discrete slugs. This process is known as "WAG" for "water-alternating-gas". In the simulations used in this study, continuous water-solvent injection at a fixed fraction rather than true WAG was employed. It is demonstrated that the two methods give equivalent results. In summary, this work is the first comprehensive study of the behavior of stratified reservoirs undergoing water-solvent injection.

Moon, Gary Michael

1993-01-01T23:59:59.000Z

317

Motility fractionation of bacteria by centrifugation  

E-Print Network (OSTI)

Centrifugation is a widespread laboratory technique used to separate mixtures into fractions characterized by a specific size, weight or density. We demonstrate that centrifugation can be also used to separate swimming cells having different motility. To do this we study self-propelled bacteria under the influence of an external centrifugal field. Using dynamic image correlation spectroscopy we measure the spatially resolved motility of bacteria after centrifugation. A significant gradient in swimming-speeds is observed for increasing centrifugal speeds. Our results can be reproduced by a model that treats bacteria as "hot" colloidal particles having a diffusion coefficient that depends on the swimming speed.

Claudio Maggi; Alessia Lepore; Jacopo Solari; Alessandro Rizzo; Roberto Di Leonardo

2013-10-10T23:59:59.000Z

318

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

319

Polyfunctional catalyst for processiing benzene fractions  

SciTech Connect

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

320

Void fraction system computer software design description  

DOE Green Energy (OSTI)

This document describes the software that controls the void fraction instrument. The format of the document may differ from typical Software Design Reports because it was created with a graphical programming language. Hardware is described in Section 2. The purpose of this document is describe the software, so the hardware description is brief. Software is described in Section 3. LabVIEW was used to develop the viscometer software, so Section 3 begins with an introduction to LabVIEW. This is followed by a description of the main program. Finally each Westinghouse developed subVI (sub program) is discussed.

Gimera, M.

1995-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
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321

Reducing the longitudinal emittance of the 8-GeV beam via the rf manipulation in a booster cycle  

Science Conference Proceedings (OSTI)

Bunch rotation will cause the longitudinal emittance growth whenever there are far more A rf stations than B rf stations, or vice versa. An alternate method via optimizing the RFSUM curve in a Booster cycle has been investigated using the ESME simulation. Since the rf manipulation at transition crossing can reduce the longitudinal emittance 31% and the momentum spread 17%, eventually, the rms momentum spread of 2.98 MeV and the longitudinal emittance of 0.061 eV {center_dot} sec with 95% of the beam can be achieved at 8-GeV.

Yang, Xi; Lebedev, Valeri A.; Ankenbrandt, Charles M.; /Fermilab

2005-08-01T23:59:59.000Z

322

Process for stabilization of coal liquid fractions  

SciTech Connect

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

323

Fractionating Recalcitrant Lignocellulose at Modest Reaction Conditions  

Science Conference Proceedings (OSTI)

Effectively releasing the locked polysaccharides from recalcitrant lignocellulose to fermentable sugars is among the greatest technical and economic barriers to the realization of lignocellulose biorefineries because leading lignocellulose pre-treatment technologies suffer from low sugar yields, and/or severe reaction conditions, and/or high cellulase use, narrow substrate applicability, and high capital investment, etc. A new lignocellulose pre-treatment featuring modest reaction conditions (50 C and atmospheric pressure) was demonstrated to fractionate lignocellulose to amorphous cellulose, hemicellulose, lignin, and acetic acid by using a non-volatile cellulose solvent (concentrated phosphoric acid), a highly volatile organic solvent (acetone), and water. The highest sugar yields after enzymatic hydrolysis were attributed to no sugar degradation during the fractionation and the highest enzymatic cellulose digestibility ({approx}97% in 24 h) during the hydrolysis step at the enzyme loading of 15 filter paper units of cellulase and 60 IU of beta-glucosidase per gram of glucan. Isolation of high-value lignocellulose components (lignin, acetic acid, and hemicellulose) would greatly increase potential revenues of a lignocellulose biorefinery.

Zhang, Y.-H. Percival [Virginia Polytechnic Institute and State University (Virginia Tech); Ding, Shi-You [National Energy Renewable Laboratory; Mielenz, Jonathan R [ORNL; Cui, Jing-Biao [Dartmouth College; Elander, Richard T. [Dartmouth College; Laser, Mark [Dartmouth College; Himmel, Michael [ORNL; McMillan, James R. [National Energy Renewable Laboratory; Lynd, L. [Dartmouth College

2007-01-01T23:59:59.000Z

324

Tank SY-101 void fraction instrument functional design criteria  

DOE Green Energy (OSTI)

This document presents the functional design criteria for design, analysis, fabrication, testing, and installation of a void fraction instrument for Tank SY-101. This instrument will measure the void fraction in the waste in Tank SY-101 at various elevations.

McWethy, L.M.

1994-10-18T23:59:59.000Z

325

5.3.3.4. Fractional factorial designs  

Science Conference Proceedings (OSTI)

Full factorial experiments can require many runs, The ASQC (1983) Glossary & Tables for Statistical Quality Control defines fractional factorial ...

2013-10-30T23:59:59.000Z

326

BROADBAND ANTENNA MATCHING NETWORK DESIGN AND APPLICATION FOR RF PLASMA ION SOURCE  

SciTech Connect

The RF ion source at Spallation Neutron Source has been upgraded to meet higher beam power requirement. One important subsystem for efficient operation of the ion source is the 2MHz RF impedance matching network. The real part of the antenna impedance is very small and is affected by plasma density for 2MHz operating frequency. Previous impedance matching network for the antenna has limited tuning capability to cover this potential variation of the antenna impedance since it employed a single tuning element and an impedance transformer. A new matching network with two tunable capacitors has been built and tested. This network can allow precision matching and increase the tunable range without using a transformer. A 5-element broadband matching network also has been designed, built and tested. The 5-element network allows wide band matching up to 50 kHz bandwidth from the resonance center of 2 MHz. The design procedure, simulation and test results are presented.

Shin, Ki [ORNL; Kang, Yoon W [ORNL; Piller, Chip [ORNL; Fathy, Aly [University of Tennessee, Knoxville (UTK)

2011-01-01T23:59:59.000Z

327

A new approach to calculate the transport matrix in RF cavities  

SciTech Connect

A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm will be implemented into the MARS15 code. A realistic approach to calculate the transport matrix in RF cavities is developed. Complete agreement for tracking results with existed code ASTRA is achieved. New algorithm will be implemented into MARS15 code.

Eidelman, Yu.; /Novosibirsk, IYF; Mokhov, N.; Nagaitsev, S.; Solyak, N.; /Fermilab

2011-03-01T23:59:59.000Z

328

A high-gradient high-duty-factor RF photo-cathode electron gun  

Science Conference Proceedings (OSTI)

We describe the analysis and preliminary design of a high-gradient, high-duty factor RF photocathode gun. The gun is designed to operate at high repetition rate or CW, with high gradient on the cathode surface to minimize emittance growth due to space charge forces at high bunch charge. The gun may also be operated in a solenoidal magnetic field for emittance compensation. The design is intended for use in short-pulse, high-charge, and high-repetition rate applications such as linac based X-ray sources. We present and compare the results of gun simulations using different codes, as well as RF and thermal analysis of the structure.

Robert Rimmer; N. Hartman; S. Lidia; S.H. Wang

2002-08-01T23:59:59.000Z

329

Options for an 11 GeV RF Beam Separator for the Jefferson Lab CEBAF Upgrade  

Science Conference Proceedings (OSTI)

The CEBAF accelerator at Jefferson Lab has had, since first demonstration in 1996, the ability to deliver a 5-pass electron beam to experimental halls (A, B, and C) simultaneously. This capability was provided by a set of three, room temperature 499 MHz rf separators in the 5th pass beamline. The separator was two-rod, TEM mode type resonator, which has a high shunt impedance. The maximum rf power to deflect the 6 GeV beams was about 3.4kW. The 12 GeV baseline design does not preserve the capability of separating the 5th pass, 11 GeV beam for the 3 existing halls. Several options for restoring this capability, including extension of the present room temperature system or a new superconducting design in combination with magnetic systems, are under investigation and are presented.

Jean Delayen, Michael Spata, Haipeng Wang

2009-05-01T23:59:59.000Z

330

Beam loading compensation of traveling wave linacs through the time dependence of the rf drive  

SciTech Connect

Beam loading in traveling-wave linear accelerating structures leads to unacceptable spread of particle energies across an extended train of bunched particles due to beam-induced field and dispersion. Methods for modulating the rf power driving linacs are effective at reducing energy spread, but for general linacs do not have a clear analytic foundation. We report here methods for calculating how to modulate the rf drive in arbitrarily nonuniform traveling-wave linacs within the convective-transport (power-diffusion) model that results in no additional energy spread due to beam loading (but not dispersion). Varying group velocity, loss factor, and cell quality factor within a structure, and nonzero particle velocity, are handled.

Towne N.; Rose J.

2011-09-30T23:59:59.000Z

331

Advanced Photon Source RF Beam Position Monitor System Upgrade Design and Commissioning  

E-Print Network (OSTI)

This paper describes the Advanced Photon Source (APS) storage ring mono-pulse rf beam position monitor (BPM) system upgrade. The present rf BPM system requires a large dead time of 400 ns between the measured bunch and upstream bunch. The bunch pattern is also constrained by the required target cluster of six bunches of 7 mA minimum necessary to operate the receiver near the top end of the dynamic range. The upgrade design objectives involve resolving bunches spaced as closely as 100 ns. These design objectives require us to reduce receiver front-end losses and reflections. An improved trigger scheme that minimizes systematic errors is also required. The upgrade is in the final phases of installation and commissioning at this time. The latest experimental and commissioning data and results will be presented.

Lill, R; Singh, O

2001-01-01T23:59:59.000Z

332

Progress on the high-current 704 MHz superconducting RF cavity at BNL  

Science Conference Proceedings (OSTI)

The 704 MHz high current superconducting cavity has been designed with consideration of both performance of fundamental mode and damping of higher order modes. A copper prototype cavity was fabricated by AES and delivered to BNL. RF measurements were carried out on this prototype cavity, including fundamental pass-band and HOM spectrum measurements, HOM studies using bead-pull setup, prototyping of antenna-type HOM couplers. The measurements show that the cavity has very good damping for the higher-order modes, which was one of the main goals for the high current cavity design. 3D cavity models were simulated with Omega3P code developed by SLAC to compare with the measurements. The paper describes the cavity design, RF measurement setups and results for the copper prototype. The progress with the niobium cavity fabrication will also be described.

Xu W.; Astefanous, C.; Belomestnykh, S.; Ben-Zvi, I.; et al

2012-05-20T23:59:59.000Z

333

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

SciTech Connect

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

334

Enhancement of RF Breakdown Threshold of Microwave Cavities by Magnetic Insulation  

Science Conference Proceedings (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

335

Carbon-Fibre-Reinforced Laminates for the Tuning Structure of the LHC RF Cavities  

E-Print Network (OSTI)

A carbon-fibre-reinforced tube is proposed for the tuning structure of the superconducting RF cavities of the Large Hadron Collider (LHC). It has a high axial stiffness and provides thermal insulation between the cold RF cavity and the tuning actuator at room temperature. The tube is subjected to a high number of mechanical load cycles, high temperature gradients, thermal cycling, and ionizing radiation. Laminate theory is applied to a simplified model of the tube for a failure analysis. Long duration fatigue tests under nominal mechanical and thermal loads were performed on two tubes. The tubes were examined before and after the fatigue tests by geometric measurements, microscopy, and ultrasonic inspection. No damage such as fibre breakage, delamination, or matrix micro cracking could be detected.

Pflanz, G; Tischhauser, Johann

1997-01-01T23:59:59.000Z

336

Self-similarity in financial markets: A fractionally integrated approach  

Science Conference Proceedings (OSTI)

This study discussed the self-similar processes using the fractionally integrated methodology in three selected global financial equity markets. Under the heavy-tailed assumption, the symmetric and asymmetric fractionally integrated time varying volatility ... Keywords: Econophysics, Financial time series, Fractionally integrated model, Long memory process, Self-similarity

Chin Wen Cheong

2010-08-01T23:59:59.000Z

337

Some Applications of the Fractional Poisson Probability Distribution  

E-Print Network (OSTI)

Physical and mathematical applications of fractional Poisson probability distribution have been presented. As a physical application, a new family of quantum coherent states has been introduced and studied. As mathematical applications, we have discovered and developed the fractional generalization of Bell polynomials, Bell numbers, and Stirling numbers. Appearance of fractional Bell polynomials is natural if one evaluates the diagonal matrix element of the evolution operator in the basis of newly introduced quantum coherent states. Fractional Stirling numbers of the second kind have been applied to evaluate skewness and kurtosis of the fractional Poisson probability distribution function. A new representation of Bernoulli numbers in terms of fractional Stirling numbers of the second kind has been obtained. A representation of Schlafli polynomials in terms of fractional Stirling numbers of the second kind has been found. A new representations of Mittag-Leffler function involving fractional Bell polynomials and fractional Stirling numbers of the second kind have been discovered. Fractional Stirling numbers of the first kind have been introduced and studied. Two new polynomial sequences associated with fractional Poisson probability distribution have been launched and explored. The relationship between new polynomials and the orthogonal Charlier polynomials has also been investigated. In the limit case when the fractional Poisson probability distribution becomes the Poisson probability distribution, all of the above listed developments and implementations turn into the well-known results of quantum optics, the theory of combinatorial numbers and the theory of orthogonal polynomials of discrete variable.

Nick Laskin

2008-12-05T23:59:59.000Z

338

Robust RF Switch Yields Enhanced Communication Capabilities (ANL-IN-09-053 and ANL-IN-09-070)  

Scientists at Argonne National Laboratory have created a special radio frequency (RF) microelectromechanical system (MEMS) switch based on ultra nanocrystalline diamond (UNCD) as a dielectric that promises a next generation of military and commercial ...

339

Charge-domain signal processing of direct RF sampling mixer with discrete-time filters in Bluetooth and GSM receivers  

Science Conference Proceedings (OSTI)

RF circuits for multi-GHz frequencies have recently migrated to low-cost digital deep-submicron CMOS processes. Unfortunately, this process environment, which is optimized only for digital logic and SRAM memory, is extremely unfriendly for conventional ...

Yo-Chuol Ho; Robert Bogdan Staszewski; Khurram Muhammad; Chih-Ming Hung; Dirk Leipold; Kenneth Maggio

2006-04-01T23:59:59.000Z

340

One-dimensional hybrid simulation of the dc/RF combined driven capacitively coupled CF{sub 4} plasmas  

Science Conference Proceedings (OSTI)

We developed a one-dimensional hybrid model to simulate the dc/RF combined driven capacitively coupled plasma for CF{sub 4} discharges. The numerical results show the influence of the dc source on the plasma density distribution, ion energy distributions (IEDs), and ion angle distributions (IADs) on both RF and dc electrodes. The increase of dc voltage impels more ions with high energy to the electrode applied to the dc source, which makes the IEDs at the dc electrode shift toward higher energy and the peaks in IADs shift toward the small angle region. At the same time, it also decreases ion-energy at the RF electrode and enlarges the ion-angles which strike the RF electrode.

Wang Shuai [School of Science, Northeastern University, Shenyang 110891 (China); Xu Xiang; Wang Younian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2012-11-15T23:59:59.000Z

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.


341

Exploring predistortion training algorithms in a Cartesian feedback-trained digital predistortion system for RF power amplifier linearization  

E-Print Network (OSTI)

A Cartesian feedback-trained digital predistortion system for RF power amplifier linearization offers many advantages with its combination of two different linearization techniques. This thesis describes such a system, ...

Huang, Jeffrey B

2006-01-01T23:59:59.000Z

342

Software-Defined Ultra-wideband Radio Communications: A New RF Technology for Emergency Response Applications  

SciTech Connect

Reliable wireless communication links for local-area (short-range) and regional (long-range) reach capabilities are crucial for emergency response to disasters. Lack of a dependable communication system can result in disruptions in the situational awareness between the local responders in the field and the emergency command and control centers. To date, all wireless communications systems such as cell phones and walkie-talkies use narrowband radio frequency (RF) signaling for data communication. However, the hostile radio propagation environment caused by collapsed structures and rubble in various disaster sites results in significant degradation and attenuation of narrowband RF signals, which ends up in frequent communication breakdowns. To address the challenges of reliable radio communication in disaster fields, we propose an approach to use ultra-wideband (UWB) or wideband RF waveforms for implementation on Software Defined Radio (SDR) platforms. Ultra-wideband communications has been proven by many research groups to be effective in addressing many of the limitations faced by conventional narrowband radio technologies. In addition, LLNL's radio and wireless team have shown significant success in field deployment of various UWB communications system for harsh environments based on LLNL's patented UWB modulation and equalization techniques. Furthermore, using software defined radio platform for UWB communications offers a great deal of flexibility in operational parameters and helps the radio system to dynamically adapt itself to its environment for optimal performance.

Nekoogar, F; Dowla, F

2009-10-19T23:59:59.000Z

343

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

Science Conference Proceedings (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

344

Design of a new VHF RF power amplifier system for LANSCE  

Science Conference Proceedings (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

345

HIGH POWER TEST OF RF SEPARATOR FOR 12 GEV UPGRADE OF CEBAF AT JLAB  

Science Conference Proceedings (OSTI)

CEBAF at JLab is in the process of an energy upgrade from 6 GeV to 12 GeV. The existing setup of the RF separator cavities in the 5th pass will not be adequate to extract the highest energy (11 GeV) beam to any two existing halls (A, B or C) while simultaneously delivering to the new hall D in the case of the proposed 12 GeV upgrade of the machine. To restore this capability, we are exploring the possibility of extension of existing normal conducting 499 MHz TEM-type rf separator cavities. Detailed numerical studies suggest that six 2-cell normal conducting structures meet the requirements; each 2-cell structure will require up to 4 kW RF input power in contrast with the current nominal operating power of 1.0 to 2.0 kW. A high power test of 4 kW confirms that the cavity meet the requirement.

S. Ahmed, M. Wissmann, J. Mammosser, C. Hovater, M. Spata, G. Krafft, J. Delayen

2012-07-01T23:59:59.000Z

346

Integrated design and analysis of rf heating and current drive systems  

SciTech Connect

The design, analysis, and performance evaluation of rf power systems ultimately requires accurate modeling of a chain of subsystems starting with the rf transmitter and ending with the power absorption in the plasma. A collection of computer codes is used at ORNL to calculate the plasma loading and wave spectrum for a three-dimensional rf antenna, the transmission/reflection properties of the Faraday shield and its effect on the electrical characteristics and phase velocity of the antenna, the internal coupling among antenna array components and the incorporation of the antenna array into a transmission line model of the phase control, tuning, matching, and power distribution system. Some codes and techniques are more suited for the rapid evaluation of system design progressions, while others are more applicable to the detailed analysis of final designs or existing hardware. The interaction of codes and the accuracy of calculations will be illustrated by the process of determining the plasma loading as a function of phasing and density profiles for the TFTR ICRH antennas and comparing the results to measurements. An example of modeling a complex antenna geometry will be the comparison of calculations with the measured electrical response of a four-strap mockup of the JET A2 antenna array which was loaned to ORNL by the JET ICRH team.

Ryan, P.M.; Carter, M.D.; Goulding, R.H. [and others

1995-09-01T23:59:59.000Z

347

The Development of RF Heating of Magnetically Confined Deuterium-Tritium Plasmas  

SciTech Connect

The experimental and theoretical development of ion cyclotron radiofrequency heating (ICRF) in toroidal magnetically-confined plasmas recently culminated with the demonstration of ICRF heating of D-T plasmas, first in the Tokamak Fusion Test Reactor (TFTR) and then in the Joint European Torus (JET). Various heating schemes based on the cyclotron resonances between the plasma ions and the applied ICRF waves have been used, including second harmonic tritium, minority deuterium, minority helium-3, mode conversion at the D-T ion-ion hybrid layer, and ion Bernstein wave heating. Second harmonic tritium heating was first shown to be effective in a reactor-grade plasma in TFTR. D-minority heating on JET has led to the achievement of Q = 0.22, the ratio of fusion power produced to RF power input, sustained over a few energy confinement times. In this paper, some of the key building blocks in the development of rf heating of plasmas are reviewed and prospects for the development of advanced methods of plasma control based on the application of rf waves are discussed.

B.P. LeBlanc; C.K. Phillips; J.C. Hosea; R. Majeski; S. Bernabei [and others

1999-06-01T23:59:59.000Z

348

Fundamentals of Biomass Pretreatment by Fractionation  

NLE Websites -- All DOE Office Websites (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,

349

Fractional cut: Improved recursive bisection placement  

E-Print Network (OSTI)

In this paper, we present improvements to recursive bisection based placement. In contrast to prior work, our horizontal cut lines are not restricted to row boundaries; this avoids a “narrow region” problem. To support these new cut line positions, a dynamic programming based legalization algorithm has been developed. The combination of these has improved the stability and lowered the wire lengths produced by our Feng Shui placement tool. On benchmarks derived from industry partitioning examples, our results are close to those of the annealing based tool Dragon, while taking only a fraction of the run time. On synthetic benchmarks, our wire lengths are nearly 23 % better than those of Dragon. For both benchmark suites, our results are substantially better than those of the recursive bisection based tool Capo and the analytic placement tool Kraftwerk. 1.

Ameya Agnihotri; Mehmet Can; Yildiz Ateen; Khatkhate Ajita; Mathur Satoshi; Ono Patrick; H. Madden

2003-01-01T23:59:59.000Z

350

ABJ Fractional Brane from ABJM Wilson Loop  

E-Print Network (OSTI)

We present a new Fermi gas formalism for the ABJ matrix model. This formulation takes a form that identifies the effect of the fractional M2-brane in the ABJ matrix model as that of a composite Wilson loop operator in the corresponding ABJM matrix model. Using this formalism, we study the phase dependence of the ABJ partition function numerically and find a simple rule for it. We further compute first few exact values at some coupling constants. Fitting these exact values against the expected form of the grand potential we can write down the grand potential with exact coefficients. The results at various coupling constants enable us to conjecture an explicit form of the grand potential for general coupling constants. This matches with a natural generalization of the perturbative sum, worldsheet instantons and bound states from the ABJM matrix model, but contains a minor difference in the membrane instantons.

Sho Matsumoto; Sanefumi Moriyama

2013-10-30T23:59:59.000Z

351

Fractional diffusion modeling of ion channel gating  

E-Print Network (OSTI)

An anomalous diffusion model for ion channel gating is put forward. This modeling scheme is able to describe the non-exponential, power-law like gating behavior of residence time intervals in several types of ion channels. Our scheme presents a generalization of the discrete diffusion model by Millhauser, Salpeter and Oswald [Proc. Natl. Acad. Sci. USA 85, 1503 (1988)] to the case of a continuous, anomalously slow conformational diffusion. The corresponding generalization is derived from a continuous time random walk composed of nearest neighbor jumps which in the scaling limit results in a fractional diffusion equation. The studied model contains three parameters only: the mean residence time, a characteristic time of conformational diffusion, and the index of subdiffusion. A tractable analytical expression for the characteristic function of the residence time distribution (RTD) is obtained. In the limiting case of normal diffusion a prior result of Goychuk and Hanggi [Proc. Natl. Acad. Sci. USA 99, 3552 (20...

Goychuk, I; Goychuk, Igor; Hanggi, Peter

2004-01-01T23:59:59.000Z

352

Use of a Geographic Mapping Tool in Power Line Routing for RF Hazard Identification: A Feasibility Evaluation  

Science Conference Proceedings (OSTI)

Radiofrequency (RF) fields induce currents and voltages on conductive objects with the general finding that larger or longer or taller objects, such as power lines and tall cranes, can result in greater currents and voltages. Medium wave frequencies (MF) associated with operation of AM radio broadcast stations are particularly prone to induction of RF voltages on long and/or tall cables that present the potential for arcing to ground or personnel who may initiate contact with the conductor. MF includes t...

2011-11-16T23:59:59.000Z

353

Fractional Calculus in Hydrologic Modeling: A Numerical Perspective  

Science Conference Proceedings (OSTI)

Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.

David A. Benson; Mark M. Meerschaert; Jordan Revielle

2012-01-01T23:59:59.000Z

354

1-D fluid model of atmospheric-pressure rf He+O{sub 2} cold plasmas: Parametric study and critical evaluation  

SciTech Connect

In this paper atmospheric-pressure rf He+O{sub 2} cold plasmas are studied by means of a 1-D fluid model. 17 species and 60 key reactions selected from a study of 250+ reactions are incorporated in the model. O{sub 2}{sup +}, O{sub 3}{sup -}, and O are the dominant positive ion, negative ion, and reactive oxygen species, respectively. Ground state O is mainly generated by electron induced reactions and quenching of atomic and molecular oxygen metastables, while three-body reactions leading to the formation of O{sub 2} and O{sub 3} are the main mechanisms responsible for O destruction. The fraction of input power dissipated by ions is {approx}20%. For the conditions considered in the study {approx}6% of the input power is coupled to ions in the bulk and this amount will increase with increasing electronegativity. Radial and electrode losses of neutral species are in most cases negligible when compared to gas phase processes as these losses are diffusion limited due to the large collisionality of the plasma. The electrode loss rate of neutral species is found to be nearly independent of the surface adsorption probability p for p > 0.001 and therefore plasma dosage can be quantified even if p is not known precisely.

Yang Aijun; Wang Xiaohua; Rong Mingzhe; Liu Dingxin [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); Iza, Felipe [School of Electronic, Electrical and Systems Engineering, Loughborough University, Loughborough LE11 3TU (United Kingdom); Kong, Michael G. [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China); School of Electronic, Electrical and Systems Engineering, Loughborough University, Loughborough LE11 3TU (United Kingdom)

2011-11-15T23:59:59.000Z

355

Fractionalization of Interstitials in Curved Colloidal Crystals  

E-Print Network (OSTI)

Understanding the out-of equilibrium behaviour of point defects in crystals, yields insights into the nature and fragility of the ordered state, as well as being of great practical importance. In some rare cases defects are spontaneously healed - a one-dimensional crystal formed by a line of identical charged particles, for example, can accommodate an interstitial (extra particle) by a re-adjusting all particle positions to even out the spacing. In sharp contrast, particles organized into a perfect hexagonal crystal in the plane cannot accommodate an interstitial by a simple re-adjustment of the particle spacing - the interstitial remains instead trapped between lattice sites and diffuses by hopping, leaving the crystal permanently defected. Here we report on the behavior of interstitials in colloidal crystals on curved surfaces. Using optical tweezers operated independently of three dimensional imaging, we insert a colloidal interstitial in a lattice of similar particles on flat and curved (positively and negatively) oil-glycerol interfaces and image the ensuing dynamics. We find that, unlike in flat space, the curved crystals self-heal through a collective rearrangement that re-distributes the increased density associated with the interstitial. The self-healing process can be interpreted in terms of an out of equilibrium interaction of topological defects with each other and with the underlying curvature. Our observations suggest the existence of "particle fractionalization" on curved surface crystals.

William T. M. Irvine; Mark J. Bowick; Paul M. Chaikin

2013-10-11T23:59:59.000Z

356

A real-time respiration position based passive breath gating equipment for gated radiotherapy: A preclinical evaluation  

Science Conference Proceedings (OSTI)

Purpose: To develop a passive gating system incorporating with the real-time position management (RPM) system for the gated radiotherapy. Methods: Passive breath gating (PBG) equipment, which consists of a breath-hold valve, a controller mechanism, a mouthpiece kit, and a supporting frame, was designed. A commercial real-time positioning management system was implemented to synchronize the target motion and radiation delivery on a linear accelerator with the patient's breathing cycle. The respiratory related target motion was investigated by using the RPM system for correlating the external markers with the internal target motion while using PBG for passively blocking patient's breathing. Six patients were enrolled in the preclinical feasibility and efficiency study of the PBG system. Results: PBG equipment was designed and fabricated. The PBG can be manually triggered or released to block or unblock patient's breathing. A clinical workflow was outlined to integrate the PBG with the RPM system. After implementing the RPM based PBG system, the breath-hold period can be prolonged to 15-25 s and the treatment delivery efficiency for each field can be improved by 200%-400%. The results from the six patients showed that the diaphragm motion caused by respiration was reduced to less than 3 mm and the position of the diaphragm was reproducible for difference gating periods. Conclusions: A RPM based PBG system was developed and implemented. With the new gating system, the patient's breath-hold time can be extended and a significant improvement in the treatment delivery efficiency can also be achieved.

Hu Weigang; Xu Anjie; Li Guichao; Zhang Zhen; Housley, Dave; Ye Jinsong [Department of Radiation Oncology, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Department of Radiation Oncology, Swedish Cancer Institute, Seattle, Washington 98104 (United States)

2012-03-15T23:59:59.000Z

357

Respiration-Correlated Image Guidance Is the Most Important Radiotherapy Motion Management Strategy for Most Lung Cancer Patients  

Science Conference Proceedings (OSTI)

Purpose: The purpose of this study was to quantify the effects of four-dimensional computed tomography (4DCT), 4D image guidance (4D-IG), and beam gating on calculated treatment field margins in a lung cancer patient population. Materials and Methods: Images were acquired from 46 lung cancer patients participating in four separate protocols at three institutions in Europe and the United States. Seven patients were imaged using fluoroscopy, and 39 patients were imaged using 4DCT. The magnitude of respiratory tumor motion was measured. The required treatment field margins were calculated using a statistical recipe (van Herk M, et al. Int J Radiat Oncol Biol Phys 2000;474:1121-1135), with magnitudes of all uncertainties, except respiratory peak-to-peak displacement, the same for all patients, taken from literature. Required margins for respiratory motion management were calculated using the residual respiratory tumor motion for each patient for various motion management strategies. Margin reductions for respiration management were calculated using 4DCT, 4D-IG, and gated beam delivery. Results: The median tumor motion magnitude was 4.4 mm for the 46 patients (range 0-29.3 mm). This value corresponded to required treatment field margins of 13.7 to 36.3 mm (median 14.4 mm). The use of 4DCT, 4D-IG, and beam gating required margins that were reduced by 0 to 13.9 mm (median 0.5 mm), 3 to 5.2 mm (median 5.1 mm), and 0 to 7 mm (median 0.2 mm), respectively, to a total of 8.5 to 12.4 mm (median 8.6 mm). Conclusion: A respiratory management strategy for lung cancer radiotherapy including planning on 4DCT scans and daily image guidance provides a potential reduction of 37% to 47% in treatment field margins. The 4D image guidance strategy was the most effective strategy for >85% of the patients.

Korreman, Stine, E-mail: korreman@ruc.dk [Department of Science, Systems and Models, Roskilde University, Roskilde (Denmark); Department of Radiation Oncology, The Finsen Centre, Rigshospitalet, Copenhagen (Denmark); Niels Bohr Institute, University of Copenhagen, Copenhagen (Denmark); Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison (United States); Persson, Gitte; Nygaard, Ditte [Department of Radiation Oncology, The Finsen Centre, Rigshospitalet, Copenhagen (Denmark); Brink, Carsten [Laboratory of Radiation Physics, Odense University Hospital, Odense (Denmark); Faculty of Health Sciences, University of Southern Denmark, Odense (Denmark); Juhler-Nottrup, Trine [Department of Oncology, Herlev Hospital, Copenhagen (Denmark)

2012-07-15T23:59:59.000Z

358

Influence of projectile neutron number in the {sup 208}Pb({sup 48}Ti, n){sup 255}Rf and {sup 208}Pb({sup 50}Ti, n){sup 257}Rf reactions  

Science Conference Proceedings (OSTI)

Four isotopes of rutherfordium, {sup 254-257}Rf, were produced by the {sup 208}Pb({sup 48}Ti, xn){sup 256-x}Rf and {sup 208}Pb({sup 50}Ti, xn){sup 258-x}Rf reactions (x=1,2) at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Excitation functions were measured for the 1n and 2n exit channels. A maximum likelihood technique, which correctly accounts for the changing cross section at all energies subtended by the targets, was used to fit the 1n data to allow a more direct comparison between excitation functions obtained under different experimental conditions. The maximum 1n cross sections of the {sup 208}Pb({sup 48}Ti, n){sup 255}Rf and {sup 208}Pb({sup 50}Ti, n){sup 257}Rf reactions obtained from fits to the experimental data are 0.38{+-}0.07 nb and 40{+-}5 nb, respectively. Excitation functions for the 2n exit channel were also measured, with maximum cross sections of 0.40{sub -0.17}{sup +0.27} nb for the {sup 48}Ti induced reaction, and 15.7{+-}0.2 nb for the {sup 50}Ti induced reaction. The impact of the two neutron difference in the projectile on the 1n cross section is discussed. The results are compared to the Fusion by Diffusion model developed by Swiatecki, Wilczynska, and Wilczynski.

Dragojevic, I.; Garcia, M. A.; Gates, J. M.; Nelson, S. L.; Nitsche, H. [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Gregorich, K. E.; Stavsetra, L.; Sudowe, R. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Duellmann, Ch. E. [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Abteilung Kernchemie, Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany)

2008-08-15T23:59:59.000Z

359

Power-law Spatial Dispersion from Fractional Liouville Equation  

E-Print Network (OSTI)

A microscopic model in the framework of fractional kinetics to describe spatial dispersion of power-law type is suggested. The Liouville equation with the Caputo fractional derivatives is used to obtain the power-law dependence of the absolute permittivity on the wave vector. The fractional differential equations for electrostatic potential in the media with power-law spatial dispersion are derived. The particular solutions of these equations for the electric potential of point charge in this media are considered.

Vasily E. Tarasov

2013-07-18T23:59:59.000Z

360

RF tests of an 805 MHz pillbox cavity at Lab G of Fermilab  

SciTech Connect

We report recent high power RF tests on an 805 MHz RF pillbox cavity with demountable windows for beam apertures at Lab G of Fermilab, a dedicated facility for testing of MUCOOL (muon cooling) components. The cavity is installed inside a superconducting solenoidal magnet. A 12 MW peak RF power klystron is used for the tests. The cavity has been processed both with and without magnetic field. Without magnetic field, a gradient of 34 MV/m was reached rather quickly with very low sparking rate. In a 2.5 T solenoidal field, a 16 MV/m gradient was achieved, and it had to take many weeks of conditioning. Strong multipacting effects associated with high radiation levels were measured during the processing with the magnetic field. More recently Be windows with TiN-coated surface have been installed and tested at conditions of with and without the external magnetic field. A conservative 16 MV/m gradient without magnetic field was reached quickly as planned. Less multipacting was observed during the conditioning, it indicated that the TiN-coated surface on the windows had indeed helped to reduce the secondary electron emissions significantly. A modest gradient of 16.5 MV/m was finally achieved with magnet on in solenoidal mode and the field up to 4 T. Preliminary inspection on Be windows surface found no damage at all, in comparison with Cu windows where substantial surface damage was found. Preliminary understanding of conditioning cavity in a strong magnetic field has been developed. More through window and cavity surface inspection is under way.

Li, Derun; Corlett, J.; MacGill, R.; Wallig, J.; Zisman, M.; Moretti, A.; Qian , Z.; Wu, V.; Rimmer, R.; Norem, J.; Torun, Y.

2003-05-01T23:59:59.000Z

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.


361

Quantitative Determination of Twin Volume Fraction in TWIP Steels ...  

Science Conference Proceedings (OSTI)

By using a newly developed low-accelerating-voltage high-resolution EBSD technique, the nanotwin volume fraction can be quantitatively determined, leading ...

362

Long-Range Transport and Global Fractionation of Persistent Organic...  

NLE Websites -- All DOE Office Websites (Extended Search)

Long-Range Transport and Global Fractionation of Persistent Organic Pollutants: Insights from Multimedia Modeling Studies Speaker(s): Martin Scheringer Date: July 10, 2003 -...

363

EIA-800 WEEKLY REFINERY AND FRACTIONATOR REPORT INSTRUCTIONS  

U.S. Energy Information Administration (EIA)

EIA-800, Weekly Refinery and Fractionator Report Page 3 Crude Oil (Code 050) Report all refinery input of domestic and foreign crude oil (including ...

364

Study of the Relationship between Twin Boundary Fraction and ...  

Science Conference Proceedings (OSTI)

The twin boundary fraction, given as multiples of random distribution (MRD), ... Strain Gradient and Degradation in Magnetic Properties: Focus Transformer Steel.

365

Design of traveling wave windows for the PEP-II RF coupling network  

SciTech Connect

The waveguide windows in the PEP-II RF coupling network have to withstand high power of 500 kW. Traveling wave windows have lower power dissipation than conventional self-matched windows, thus rendering the possibility of less stringent mechanical design. The traveling wave behavior is achieved by providing a reflecting iris on each side of the window, and depending on the configuration of the irises, traveling wave windows are characterized as inductive or capacitive types. A numerical design procedure using MAFIA has been developed for traveling wave windows. The relative advantages of inductive and capacitive windows are discussed. Furthermore, the issues of bandwidth and multipactoring are also addressed.

Kroll, N.M.; Ng, C.K.; Judkins, J.; Neubauer, M.

1995-05-01T23:59:59.000Z

366

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

DOE Green Energy (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

367

Optical diagnostics for a high power, rf-inductively coupled plasma  

SciTech Connect

Emission spectroscopy and laser-induced fluorescence have been used to monitor the field and tail-flame regions of a Hull-design inductively coupled plasma. This plasma is used for a variety of syntheses including SiC, TiC, BN, A1N and diamond. Temporally- and spatially-resolved spectra of both pure Ar and Ar/gas mixtures have been studied as a function of RF power, pressure and flow rate. Preliminary data suggest that the system is far from local thermodynamic equilibrium.

Nogar, N.S.; Keaton, G.L.; Anderson, J.E.; Trkula, M.

1988-01-01T23:59:59.000Z

368

efA. r rrOea IWIt 5/rf 5eh/#,tz-  

E-Print Network (OSTI)

efA. r rrOea IWIt 5/rf 5eh/#,tz- CD®®0 Pre~~m~nary Autumn Quarter Facu~ty/Adv~ser Copy " ,,' . , . #12;I' I. i' i Time Schedule'· Preliminary . Autumn Quarter 1987 P· I I M 1 1 Laatdaytol r eregstratSln~heelChairs or with ~e..r.mobility ·llmltatlons shoulc;t procee to 2e4 Schmitz to'register or add/~op ,courses instead

Washington at Seattle, University of

369

RF Conditioning and testing of fundamental power couplers for the RIA project  

DOE Green Energy (OSTI)

The Rare Isotope Accelerator (RIA) is the highest priority of the nuclear physics community in the United States for a major new accelerator facility. A principal element of RIA will be a superconducting 1.4 GeV superconducting ion linac accelerating ions of isotopes from hydrogen to uranium onto production targets or for further acceleration by a second superconducting linac. The superconducting linac technology is closely related to that used at existing accelerators and the Spallation Neutron Source. Taking advantage of JLAB's SRF Institute facilities and expertise for the SNS project, preparation of couplers, RF conditioning and high power tests have been performed on fundamental power couplers for RIA project.

M. Stirbet; J. Popielarski; T. L. Grimm; M. Johnson

2003-09-01T23:59:59.000Z

370

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

Science Conference Proceedings (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

371

The discrete fractional random cosine and sine transforms  

E-Print Network (OSTI)

Based on the discrete fractional random transform (DFRNT), we present the discrete fractional random cosine and sine transforms (DFRNCT and DFRNST). We demonstrate that the DFRNCT and DFRNST can be regarded as special kinds of DFRNT and thus their mathematical properties are inherited from the DFRNT. Numeral results of DFRNCT and DFRNST for one and two dimensional functions have been given.

Zhengjun Liu; Qing Guo; Shutian Liu

2006-05-22T23:59:59.000Z

372

Fractional dynamics and MDS visualization of earthquake phenomena  

Science Conference Proceedings (OSTI)

This paper analyses earthquake data in the perspective of dynamical systems and fractional calculus (FC). This new standpoint uses Multidimensional Scaling (MDS) as a powerful clustering and visualization tool. FC extends the concepts of integrals and ... Keywords: Correlation indices, Fractional calculus, Multidimensional scaling, Seismic events

AntóNio M. Lopes, J. A. Tenreiro Machado, C. M. A. Pinto, A. M. S. F. Galhano

2013-09-01T23:59:59.000Z

373

A Note Basis Properties for Fractional Hydrogen Atom Equation  

E-Print Network (OSTI)

In this paper, spectral analysis of fractional Sturm Liouville problem defined on (0,1], having the singularity of type at zero and research the fundamental properties of the eigenfunctions and eigenvalues for the operator. We show that the eigenvalues and eigenfunctions of the problem are real and orthogonal, respectively. Furthermore,we give some important theorems and lemmas for fractional hydrogen atom equation.

E. Bas; F. Metin

2013-03-12T23:59:59.000Z

374

Mechanical Design and Fabrication of a New RF Power Amplifier for LANSCE  

SciTech Connect

A Full-scale prototype of a new 201.25 MHz RF Final Power Amplifier (FPA) for Los Alamos Neutron Science Center (LANSCE) has been designed, fabricated, assembled and installed in the test facility. This prototype was successfully tested and met the physics and electronics design criteria. The team faced design and manufacturing challenges, having a goal to produce 2 MW peak power at 13% duty factor, at the elevation of over 2 km in Los Alamos. The mechanical design of the final power amplifier was built around a Thales TH628 Diacrode{sup R}, a state-of-art tetrode power tube. The main structure includes Input circuit, Output circuit, Grid decoupling circuit, Output coupler, Tuning pistons, and a cooling system. Many types of material were utilized to make this new RF amplifier. The fabrication processes of the key components were completed in the Prototype Fabrication Division shop at Los Alamos National Laboratory. The critical plating procedures were achieved by private industry. The FPA mass is nearly 600 kg and installed in a beam structural support stand. In this paper, we summarize the FPA design basis and fabrication, plating, and assembly process steps with necessary lifting and handling fixtures. In addition, to ensure the quality of the FPA support structure a finite element analysis with seismic design forces has also been carried out.

Chen, Zukun [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

375

Mechanical and thermal analysis of beryllium windows for RF cavities in a muon cooling channel  

SciTech Connect

Thin beryllium windows (foils) may be utilized to increase shunt impedance of closed-cell RF cavities. These windows are subject to ohmic heating from RF currents. The resulting temperature gradients in the windows can produce out of plane displacements that detune the cavity frequency. The window displacement can be reduced or eliminated by pre-stressing the foils in tension. Because of possible variations during manufacture, it is important to quantify the actual prestress of a Be window before it is put into service. We present the thermal and mechanical analyses of such windows under typical operating conditions and describe a simple non-destructive means to quantify the pre-stress using the acoustic signature of a window. Using finite element analysis, thin plate theory and physical measurements of the vibration modes of a window we attempted to characterize the actual Be window pre-stress in a small number of commercially sourced windows (30% of yield strength is typical). This method can be used for any window material and size, but this study focused on 16 cm diameter Be Windows ranging in thickness from 125 microns to 508 microns and with varying pre-stresses. The method can be used to nondestructively test future Be windows for the desired prestress.

Li, Derun; Ladran, A.; Lozano, D.; Rimmer, R.

2002-05-30T23:59:59.000Z

376

Active high-power RF pulse compression using optically switched resonant delay lines  

DOE Green Energy (OSTI)

The authors present the design and a proof of principle experimental results of an optically controlled high power rf pulse compression system. The design should, in principle, handle few hundreds of Megawatts of power at X-band. The system is based on the switched resonant delay line theory. It employs resonant delay lines as a means of storing rf energy. The coupling to the lines is optimized for maximum energy storage during the charging phase. To discharge the lines, a high power microwave switch increases the coupling to the lines just before the start of the output pulse. The high power microwave switch, required for this system, is realized using optical excitation of an electron-hole plasma layer on the surface of a pure silicon wafer. The switch is designed to operate in the TE{sub 01} mode in a circular waveguide to avoid the edge effects present at the interface between the silicon wafer and the supporting waveguide; thus, enhancing its power handling capability.

Tantawi, S.G.; Ruth, R.D.; Vlieks, A.E. [Stanford Univ., CA (US). Stanford Linear Accelerator Center; Zolotorev, M. [Lawrence Berkeley National Lab., CA (US)

1996-11-01T23:59:59.000Z

377

R.F. heating near the lower hybrid frequency in the FM-1 spherator  

SciTech Connect

Plasma heating experiments at frequencies near the lower hybrid frequency have been carried out at modest powers (.05 to 4kW). The antenna structure operating at 68 MHz was comprised of two plates driven out of phase on the exterior of the plasma. High electron heating efficiency (greater than 40 percent) in both helium and argon plasmas was observed with only a weak density dependence. At low densities (n/sub e/ less than or equal to 1 x 10$sup 11$ cm$sup -3$), the heating was uniform across the plasma while at higher densities the heating was preferentially on the exterior portion of the plasma. The heating of the exterior of the plasma was found not to correspond to absorption at the lower hybrid resonance layer. The electron heating efficiency was found to be a weak function of rf power when the incident rf power was varied from 1 to 15 times the experimentally observed threshold power for parametric instabilities. Ion temperatures were determined by measuring the Doppler broadening of an Argon ion line using a Fabry-Perot interferometer. Low efficiency main body ion heating (1 to 3 percent) was observed. (auth)

Hawryluk, R.J.; Davis, S.L.; Schmidt, J.A.

1975-12-01T23:59:59.000Z

378

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

Science Conference Proceedings (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

379

Electromagnetic Design of RF Cavities for Accelerating Low-Energy Muons  

Science Conference Proceedings (OSTI)

A high-gradient linear accelerator for accelerating low-energy muons and pions in a strong solenoidal magnetic field has been proposed for homeland defense and industrial applications. The acceleration starts immediately after collection of pions from a target in a solenoidal magnetic field and brings decay muons, which initially have kinetic energies mostly around 15-20 MeV, to 200 MeV over a distance of {approx}10 m. At this energy, both ionization cooling and further, more conventional acceleration of the muon beam become feasible. A normal-conducting linac with external-solenoid focusing can provide the required large beam acceptances. The linac consists of independently fed zero-mode (TM{sub 010}) RF cavities with wide beam apertures closed by thin conducting edge-cooled windows. Electromagnetic design of the cavity, including its RF coupler, tuning and vacuum elements, and field probes, has been developed with the CST MicroWave Studio, and is presented.

Kurennoy, Sergey S. [Los Alamos National Laboratory

2012-05-14T23:59:59.000Z

380

Respiration in Plants  

NLE Websites -- All DOE Office Websites (Extended Search)

to have oxygen as well as animals to release energy from the sugar they make from photosynthesis. They make more than they use and hence, we are able to survive. K. VanHoeck...

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

Robert B. Laughlin and the Fractional Quantum Hall Effect  

NLE Websites -- All DOE Office Websites (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. ...

382

Experimental Estimate of Beam Loading and Minimum rf Voltage for Acceleration of High Intensity Beam in the Fermilab Booster  

E-Print Network (OSTI)

The difference between the rf voltage seen by the beam and the accelerating voltage required to match the rate of change of the Booster magnetic field is used to estimate the energy loss per beam turn. Because the rf voltage (RFSUM) and the synchronous phase can be experimentally measured, they can be used to calculate the effective accelerating voltage. Also an RFSUM reduction technique has been applied to measure experimentally the RFSUM limit at which the beam loss starts. With information on beam energy loss, the running conditions, especially for the high intensity beam, can be optimized in order to achieve a higher intensity beam from the Fermilab Booster.

Yang, X; Norem, J; Yang, Xi

2004-01-01T23:59:59.000Z

383

Experimental estimate of beam loading and minimum rf voltage for acceleration of high intensity beam in the Fermilab Booster  

SciTech Connect

The difference between the rf voltage seen by the beam and the accelerating voltage required to match the rate of change of the Booster magnetic field is used to estimate the energy loss per beam turn. Because the rf voltage (RFSUM) and the synchronous phase can be experimentally measured, they can be used to calculate the effective accelerating voltage. Also an RFSUM reduction technique has been applied to measure experimentally the RFSUM limit at which the beam loss starts. With information on beam energy loss, the running conditions, especially for the high intensity beam, can be optimized in order to achieve a higher intensity beam from the Fermilab Booster.

Xi Yang; Charles M Ankenbrandt and Jim Norem

2004-04-01T23:59:59.000Z

384

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

SciTech Connect

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

385

500 MW X-BAND RF SYSTEM OF A 0.25 GEV ELECTRON LINAC FOR ADVANCED COMPTON SCATTERING SOURCE APPLICATION  

Science Conference Proceedings (OSTI)

A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with 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, T S; Anderson, S G; Gibson, D J; Hartemann, F V; Marsh, R A; Siders, C; Barty, C P; Adolphsen, C; Jongewaard, E; Tantawi, S; Vlieks, A; Wang, J W; Raubenheimer, T

2010-05-12T23:59:59.000Z

386

Deposition of Dense SiO2 Thin Films for Electrical Insulation Applications by Microwave ECR Plasma Source Enhanced RF Reactive Magnetron Sputtering  

Science Conference Proceedings (OSTI)

Silicon dioxide thin films have been deposited successfully on high speed steel (HSS) cutting tool substrates by means of microwave electron cyclotron resonance (MW-ECR) plasma source enhanced RF reactive magnetron sputtering of a pure silica target ... Keywords: SiO2 thin films, Electrical insulation properties, RF magnetron sputtering, Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS)

Qiyong Zeng; Xiaofeng Zheng; Zhonghua Yu; Yunxian Cui

2010-03-01T23:59:59.000Z

387

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

Science Conference Proceedings (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

388

Development of a CW Superconducting RF Booster Cryomodule for Future Light Sources  

Science Conference Proceedings (OSTI)

Future light sources based on seeded free electron lasers (FEL) have the potential to increase the soft xray flux by several orders of magnitude with short bunch lengths to probe electron structure and dynamics. A low emittance, high rep-rate radio frequency (RF) photocathode electron gun will generate the electron beam that will require very stringent beam control and manipulation through the superconducting linear accelerator to maintain the high brightness required for an x-ray FEL. The initial or booster cavities of the superconducting radio frequency (SRF) linear accelerator will require stringent control of transverse kicks and higher order modes (HOM) during the beam manipulation and conditioning that is needed for emittance exchange and bunch compression. This SBIR proposal will develop, fabricate and test a continuous-wave SRF booster cryomodule specifically for this application. Phase I demonstrated the technical feasibility of the project by completing the preliminary SRF cavity and cryomodule design and its integration into an R&D test stand for beam studies at Lawrence Berkeley National Laboratory (LBNL). The five-cell bulk niobium cavities operate at 750 MHz, and generate 10 MV each with strong HOM damping and special care to eliminate transverse kicks due to couplers. Due to continuous-wave operation at fairly modest beam currents and accelerating gradients the complexity of the two cavity cryomodule is greatly reduced compared to an ILC type system. Phase II will finalize the design, and fabricate and test the booster cryomodule. The cryomodule consists of two five-cell cavities that will accelerate megahertz bunch trains with nano-coulomb charge. The accelerating gradient is a very modest 10 MV/m with peak surface fields of 20 MV/m and 42.6 mT. The cryogenic system operates at 2 K with a design dynamic load of 20 W and total required cryogenic capacity of 45 W. The average beam current of up to 1 mA corresponds to a beam power of 10 kW per 5- cell cavity and will require 20 kW of RF power for transmission, control and regulation. The RF power will be supplied by a commercial tetrode. Cryogenic tests will be carried out at LBNL to make use of their test facilities, cryogenics and laser systems, and for future use with beam. Demonstration of this new type of booster cryomodule will open many new applications of SRF linear accelerators.

Grimm, Terry L; Bogle, Andrew; Deimling, Brian; Hollister, Jerry; II, Randall Jecks; Kolka, Ahren; Romel, Chandra

2009-04-13T23:59:59.000Z

389

Improved control strategies correct main fractionator operating problems  

SciTech Connect

Heat and mass balance control of refinery main fractionators can be improved through simple process design changes. Metering flows of internal reflux streams improves unit operability and controllability. Modifying the process system design to measure small internal reflux flow is another inexpensive way to control main fractionators. Three case histories show how simple design changes in refinery main fractionators can solve advanced control problems, thus changing product yields and improving refinery economics. The three cases are a delayed coker, a crude unit, and a FCC unit.

Golden, S.W. [Process Consulting Services Inc., Dallas, TX (United States)

1995-08-21T23:59:59.000Z

390

Comparative Genomics Analysis and Phenotypic Characterization of Shewanella putrefaciens W3-18-1: Anaerobic Respiration, Bacterial Microcompartments, and Lateral Flagella  

Science Conference Proceedings (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

391

A high sensitivity ultralow temperature RF conductance and noise measurement setup  

SciTech Connect

We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milli-Kelvin temperatures. The setup relies on the combination of an interferometric amplification scheme and a quarter-wave impedance transformer, allowing the measurement of noise power spectral densities with gigahertz bandwidth up to five orders of magnitude below the amplifier noise floor. We simultaneously measure the high frequency conductance of the sample by derivating a portion of the signal to a microwave homodyne detection. We describe the principle of the setup, as well as its implementation and calibration. Finally, we show that our setup allows to fully characterize a subnanosecond on-demand single electron source. More generally, its sensitivity and bandwidth make it suitable for applications manipulating single charges at GHz frequencies.

Parmentier, F. D.; Mahe, A.; Denis, A.; Berroir, J.-M.; Glattli, D. C.; Placais, B.; Feve, G. [Laboratoire Pierre Aigrain, Ecole Normale Superieure, CNRS UMR 8551, Universite P. et M. Curie, Universite D. Diderot 24, rue Lhomond, 75231 Paris Cedex 05 (France)

2011-01-15T23:59:59.000Z

392

Multi-purpose 805 MHz Pillbox RF Cavity for Muon Acceleration Studies  

SciTech Connect

An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques. The cavity can operate at vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity is designed for easy assembly and disassembly with bolted construction using aluminum seals. The surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. Different surface treatments such as electro polished, high-pressure water cleaned, and atomic layer deposition are being considered for testing. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. Current status of the cavity prepared for initial conditioning and operation in the external magnetic field is discussed.

Kurennoy, Sergey S. [Los Alamos National Laboratory; Chan, Kwok-Chi Dominic [Los Alamos National Laboratory; Jason, Andrew [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory; Turchi, Peter J. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

393

Terahop and Lawrence Livermore National LaboratoryStructural Fire RF Testing  

SciTech Connect

The Georgia Public Safety Training Center's Live Fire Training Facility in Forsyth, GA is a three story structure constructed of rebar-reinforced concrete wall and floors. All the door and window coverings on the building are constructed of thick, plate metal to withstand the high temperatures generated inside the building during training exercises. All of the building's walls and floors are 1-foot thick, and regular concrete columns run up along the inside of the wall increasing the thickness to 20-inches in those locations. A center concrete staircase divides the structure in half. For typical exercises, fires are started in the back right corner of the building on the first floor and in the front right corner on the second floor as shown in Figure 2. Due to the high heat generated during these exercises, measured at 300 F on the floor and 700 F near the ceilings, there were limited locations at which equipment could be placed that did not incorporate heat shielding, such as the Lawrence Livermore National Laboratory's UWB system. However, upon inspection of the building, two preferable locations were identified in which equipment could be placed that would be protected from the temperature extremes generated by the fires. These locations are identified in Figure 2 as the tested TX locations. These were preferred locations because, while they protected the hardware from temperature extremes, they also force the RF transmission path through the building to cross very near the fire locations and anticipated plasma generation regions. Both of the locations listed in Figure 2 were tested by the UWB equipment and found to be suitable deployment locations to establish a solid RF link for data collection. The transmission location on the first floor was ultimately chosen for use during the actual exercises because it was accessible to the data collection team during the exercises. This allowed them to remove the hardware once the testing was complete without having to wait for the entire day of exercises to complete. Unfortunately, RF transmission directly through the central location of the fire on the first floor was not possible, so the transmission path had to be shifted approximately 6-feet off the side of the fire's center. The corner where the fire was located on the first floor was re-enforced with a mixture of concrete and metal fibers for heat resistance. This material was highly reflective, permitting very little RF energy to pass through it. This phenomenon was also observed and verified by Terahop's testing, discussed in the next section. An image of these re-enforced walls and a close up of the actual wall material containing the metal fibers can bee seen in Figure 3.

Haugen, P; Pratt, G

2007-02-26T23:59:59.000Z

394

RF/microwave non-destructive measurements of electrical properties of semiconductor wafers for thermophotovoltaic applications  

DOE Green Energy (OSTI)

A radio-frequency/microwave measurement system has been designed for non-contacting determination of sheet resistance and excess carrier lifetime of low-bandgap materials and junctions, specifically GaSb-based alloys for thermophotovoltaic (TPV) applications. The design incorporates RF circuitry in the 100--500 MHz frequency range and utilizes a Q-switched YAG laser at 1.32 microns to photo-generate electron-hole pairs and conductivity modulate the material and/or junction under test. Supplementary measurements with a GaAs pulsed diode laser at 904 nm provides a faster transient response with near-surface photogeneration. Initial measurements on GaSb substrates, Zn-diffused materials and epitaxially grown layers are presented and discussed.

Saroop, S.; Borrego, J.M.; Gutmann, R.J. [Rensselaer Polytechnic Inst., Troy, NY (United States)] [and others

1997-05-01T23:59:59.000Z

395

X-Band Active-Passive Rf Pulse Compressor with Plasma Switches  

SciTech Connect

As proposed by SLAC, the efficiency of a pulse compressor of the SLED-II type could be increased by changing both the phase of the microwave source and the coupling coefficient of the delay line. In the existing SLED-II system at frequency 11.4 GHz, the resonant delay line is coupled with the source via an iris with a constant reflection coefficient. Replacement of the iris with an active component makes it possible to create an active SLED-II system. In this paper, the use of plasma switches as the active elements is discussed. Plasma switches have been developed and tested at a high-power level for production of flattop compressed pulses. Active switching of SLED-II has demonstrated a marked increase in efficiency (by 20%) and power gain (by 37%) as compared with passive switching. The active compressor has produced 173 ns rf flattop output pulses with a power of about 112 MW.

Vikharev, A.L.; Ivanov, O.A.; Gorbachev, A.M.; /Nizhnii Novgorod, IAP /Omega-P, New Haven; Lobaev, M.A.; Isaev, V.A.; /Nizhnii Novgorod, IAP; Tantawi, S.G.; Lewandowski, J.R.; /SLAC; Hirshfield, J.L.; /Omega-P, New Haven /Yale U.

2012-04-27T23:59:59.000Z

396

Comparison Between Dust Particle Generation In CH4 or CH4/N2 Mixing RF Plasmas  

SciTech Connect

Dust particles have been spontaneously generated either in pure CH4 or in CH4/N2 r.f. plasmas. The dust particle formation results from homogeneous nucleation in the plasma and is detected by laser light scattering (Ar+, {lambda} = 514.5 nm). The temporal and spatial behaviour of dust particles is studied. In pure methane gas, particles are trapped in well defined clouds at the plasma sheath boundaries. In a CH4/N2 mixture, the nitrogen addition leads to an expansion of the clouds. For nitrogen contents higher than 50%, the space between the electrodes is nearly completely filled with dust particles leading to plasma instabilities and a void appears in the center of the discharge. The particles are spherical with diameters in the range 0.8-2 {mu}m. For nitrogen-rich plasmas, the particles growth is improved and leads to a rough shape with an orange-peel-type surface texture.

Pereira, Jeremy; Massereau-Guilbaud, Veronique; Geraud-Grenier, Isabelle; Plain, Andre [LASEP, Faculte des Sciences, Universite d'Orleans, Site de Bourges, rue G.Berger, BP 4043, 18028 Bourges Cedex (France)

2005-10-31T23:59:59.000Z

397

Focusing solenoid for the front end of a linear RF accelerator  

SciTech Connect

A prototype of a superconducting focusing solenoid for use in an RF linac has been built and tested at Fermi National Accelerator Laboratory (FNAL). The solenoid is comprised of the main coil, two bucking coils, two dipole corrector windings, and a low carbon steel flux return. At the excitation current of 250 A, the magnetic field reaches 7.2 T in the center of the solenoid and is less than 5 G on the axis at a distance of 150 mm from the center. The length of the solenoid is 150 mm; the length of a cryovessel for the solenoid with a 20 mm diameter 'warm' bore is 270 mm. This paper presents the main design features of the focusing solenoid and discusses results from tests of the solenoid.

Terechkine, I.; Kashikhin, V.V.; Page, T.; Tartaglia, M.; Tompkins, J.; /Fermilab

2007-06-01T23:59:59.000Z

398

Emittance Studies of the BNL/SLAC/UCLA 1.6 Cell Photocathode RF Gun  

SciTech Connect

The symmetrized 1.6 cell S-band photocathode gun developed by the BNL/SLAC/UCLA collaboration is in operation at the Brookhaven Accelerator Test Facility (ATF). A novel emittance compensation solenoid magnet has also been designed, built and is in operation at the ATF. These two subsystems form an emittance compensated photoinjector used for beam dynamics, advanced acceleration and free electron laser experiments at the ATF. The highest acceleration field achieved on the copper cathode is 150 MV/m, and the guns normal operating field is 130 MV/m. The maximum rf pulse length is 3 {mu}s. The transverse emittance of the photoelectron beam were measured for various injection parameters. The 1 nC emittance results are presented along with electron bunch length measurements that indicated that at above the 400 pC, space charge bunch lengthening is occurring. The thermal emittance, {epsilon}{sub o}, of the copper cathode has been measured.

Palmer, D.T.; /SLAC; Wang, X.J.; /Brookhaven; Miller, R.H.; /SLAC; Babzien, M.; Ben-Zvi, I.; /Brookhaven; Pellegrini, C.; /UCLA; Sheehan, J.; Skaritka, J.; /Brookhaven; Winick, H.; /SLAC; Woodle, M.; Yakimenko, V.; /Brookhaven

2011-09-09T23:59:59.000Z

399

Design of a mechanically actuated RF grounding system for the ITER ICRH antenna  

E-Print Network (OSTI)

In the ITER equatorial ports containing ICRH antennas, parasitic electrical resonances can be excited in the nominal 20 mm clearance gap between the port walls and the plug contained within it. RF calculations have established that these resonances can be effectively mitigated by a series of suitably located electrically conducting contacts between the port and plug. These contacts must allow installation and removal of the antenna but must also make reliable electrical contact during antenna operation. In addition, the contacts must be compliant enough to survive deflection of the port during seismic and disruption events without transmitting large forces to the vacuum vessel. The distance to be spanned is subject to significant uncertainty, due to the large manufacturing tolerances of the surrounding components, and this also must be considered during the design process. This paper outlines progress made in the design of the grounding system, as well as detailing a number of concepts which have been investi...

Hancock, D; Beaumont, B; Dumortier, P; Durodie, F; Kyrytsya, V; Louche, F; McKinley, R; Nicholls, K

2013-01-01T23:59:59.000Z

400

Diffusion Dynamics of Charged Dust Particles in Capacitively Coupled RF Discharge System  

SciTech Connect

Dusty plasma is loosely defined as electron-ion plasma with additional charged components of micron-sized dust particles. In this study, we developed a particle diagnostic technique based on light scattering and particle tracking velocimetry to investigate the dynamics of micron-sized titanium oxide particles in Argon gas capacitively coupled rf-discharge. The particle trajectories are constructed from sequence of image frames and treated as sample paths of charged Brownian motion. At specific sets of plasma parameters, disordered liquid-like dust particle configuration are observed. Mean-square-displacement of the particle trajectories are determined to characterize the transport dynamics. We showed that the dust particles in disordered liquid phase exhibit anomalous diffusion with different scaling exponents for short and large time scales, indicating the presence of slow and fast modes which can be related to caging effect and dispersive transport, respectively.

Chew, W. X.; Muniandy, S. V.; Wong, C. S.; Yap, S. L.; Tan, K. S. [Plasma Research Laboratory, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

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

High deposition rate preparation of amorphous silicon solar cells by rf glow discharge decomposition of disilane  

SciTech Connect

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

402

300 MHz RF coils for MR studies of Macaca mulatta brain at 7 Tesla Hellmut Merkle2  

E-Print Network (OSTI)

300 MHz RF coils for MR studies of Macaca mulatta brain at 7 Tesla Hellmut Merkle2 , Josef Pfeuffer, customized for a vertical ultra high field 7 Tesla system develop for vision research in the alert, trained macaque. Methods A prototype primate chair was designed and built for the vertical 7-Tesla/60-cm BRUKER

403

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 55, NO. 4, APRIL 2008 1067 Nonuniform RF Overstress in High-Power  

E-Print Network (OSTI)

voltage (VRF) across a loop, which is strongly affected by internal reflections in the device and mismatch effects. In some cases, nonuniformity in VRF occurs due to parasitic oscillations excited under actual). Digital Object Identifier 10.1109/TED.2008.916719 RF stress. Monitoring the spatial distribution of VRF

Shapira, Yoram

404

Efficient Broadband RF Energy Harvesting for Wireless Sensors Joseph A. Hagerty, Tian Zhao, Regan Zane and Zoya Popovic  

E-Print Network (OSTI)

energy coupling DC-DC converter that uses either inductive or capacitive elements for internal energy Electronics Cin Cload Cst Exfr Eop Energy Coupling DC-DC Converter Figure 2. Functional schematicEfficient Broadband RF Energy Harvesting for Wireless Sensors Joseph A. Hagerty, Tian Zhao, Regan

405

Charging effects in CdSe nanocrystals embedded in SiO2 matrix produced by rf magnetron sputtering  

Science Conference Proceedings (OSTI)

Charging effects in CdSe nanocrystals embedded in SiO"2 matrix fabricated by rf magnetron co-sputtering technique were electrically characterized by means of capacitance-voltage (C-V) combined with current-voltage (I-V). The presence of CdSe nanocrystals ... Keywords: CdSe, Charging effect, Nanocrystals, SiO2

S. Levichev; A. Chahboun; P. Basa; A. G. Rolo; N. P. Barradas; E. Alves; Zs. J. Horvath; O. Conde; M. J. M. Gomes

2008-12-01T23:59:59.000Z

406

On the electrical properties of slotted metallic planes in CMOS processes for RF and millimeter-wave applications  

Science Conference Proceedings (OSTI)

This paper presents a study of the effects of slotted metallic planes in passive structures built using CMOS processes for RF and millimeter-wave (mmW) applications. The impact of holes on the reference plane resistance and in the capacitance of any ... Keywords: CMOS manufacturing, Electromagnetic analysis, Interconnections, Metal density rules, Transmission lines, mmW integrated circuits

José Luis GonzáLez; Baudouin Martineau; Didier Belot

2012-08-01T23:59:59.000Z

407

Imaging fractional incompressible stripes in integer quantum Hall systems  

E-Print Network (OSTI)

Transport experiments provide conflicting evidence on the possible existence of fractional order within integer quantum Hall systems. In fact integer edge states sometimes behave as monolithic objects with no inner structure, while other experiments clearly highlight the role of fractional substructures. Recently developed low-temperature scanning probe techniques offer today an opportunity for a deeper-than-ever investigation of spatial features of such edge systems. Here we use scanning gate microscopy and demonstrate that fractional features were unambiguously observed in every integer quantum Hall constriction studied. We present also an experimental estimate of the width of the fractional incompressible stripes corresponding to filling factors 1/3, 2/5, 3/5, and 2/3. Our results compare well with predictions of the edge-reconstruction theory.

Nicola Paradiso; Stefan Heun; Stefano Roddaro; Lucia Sorba; Fabio Beltram; Giorgio Biasiol; L. N. Pfeiffer; K. W. West

2012-05-02T23:59:59.000Z

408

Dynamic optimization of fractionation schedules in radiation therapy  

E-Print Network (OSTI)

In this thesis, we investigate the improvement in treatment effectiveness when dynamically optimizing the fractionation scheme in radiation therapy. In the first part of the thesis, we consider delivering a different dose ...

Ramakrishnan, Jagdish

2013-01-01T23:59:59.000Z

409

Mercury Isotope Fractionation by Environmental Transport and Transformation Processes  

E-Print Network (OSTI)

isotope fractionation in fossil hydrothermal systems. Geology,isotopes: Evaporation, chemical diffusion and Soret diffusion. Chemical Geology,isotope records of atmospheric and riverine pollution from two major European heavy metal refineries. Chemical Geology,

Koster van Groos, Paul Gijsbert

2011-01-01T23:59:59.000Z

410

Thomson scattering diagnostic for the measurement of ion species fraction  

Science Conference Proceedings (OSTI)

Simultaneous Thomson scattering measurements of collective electron-plasma and ion-acoustic fluctuations have been utilized to determine ion species fraction from laser produced CH plasmas. The CH{sub 2} foil is heated with 10 laser beams, 500 J per beam, at the Omega Laser facility. Thomson scattering measurements are made 4 mm from the foil surface using a 30 J 2{omega} probe laser with a 1 ns pulse length. Using a series of target shots the plasma evolution is measured from 2.5 ns to 9 ns after the rise of the heater beams. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the two-ion species theoretical form factor for the ion feature such that the ion temperature, plasma flow velocity and ion species fraction are determined. The ion species fraction is determined to an accuracy of {+-}0.06 in species fraction.

Ross, J S; Park, H S; Amendt, A; Divol, L; Kugland, N L; Rozmus, W; Glenzer, S H

2012-05-01T23:59:59.000Z

411

Estimating Rainfall in the Tropics Using the Fractional Time Raining  

Science Conference Proceedings (OSTI)

The relationship between the fractional time raining and tropical rainfall amount is investigated using raingage data and a point process model of tropical rainfall. Both the strength and the nature of the relationship are dependent upon the ...

Mark L. Morrissey; Witold F. Krajewski; Michael J. McPhaden

1994-03-01T23:59:59.000Z

412

The fractional volatility model: An agent-based interpretation  

E-Print Network (OSTI)

Based on criteria of mathematical simplicity and consistency with empirical market data, a model with volatility driven by fractional noise has been constructed which provides a fairly accurate mathematical parametrization of the data. Here, some features of the model are discussed and, using agent-based models, one tries to find which agent strategies and (or) properties of the financial institutions might be responsible for the features of the fractional volatility model.

Mendes, R Vilela

2007-01-01T23:59:59.000Z

413

Solids Fraction Measurement with a Reflective Fiber Optic Probe  

SciTech Connect

A method has been developed to extract solids fraction information from a reflective fiber optic probe. The commercially available reflective fiber optic probe was designed to measure axial particle velocity (both up and down directions). However, the reflected light intensity measured is related to particle size and particle concentration. A light reflection model is used to relate the reflected light intensity to solids fraction. In this model we assume that the reflected light intensity is a fixed fraction, K1, of the total light intensity lost in penetration of a solid layer. Also, the solids fraction is related to particle concentration, N, in the light path, by N = K2 (1- ?), where (1-?) is the solids fraction. The parameters K1 and K2 are determined through a calibration and curve fitting procedure. This paper describes this procedure and the steps taken to derive the values of K1 and K2. It is proposed that the reflective fiber optic can be used for real time measurement of solids fraction in a circulating fluid bed.

Seachman, S.M.; Yue, P.C.; Ludlow, J.C.; Shadle, L.J.

2006-11-01T23:59:59.000Z

414

Evaluation of a RF-Based Approach for Tracking UF6 Cylinders at a Uranium Enrichment Plant  

SciTech Connect

Approved industry-standard cylinders are used globally to handle and store uranium hexafluoride (UF{sub 6}) feed, product, tails, and samples at uranium enrichment plants. The International Atomic Energy Agency (IAEA) relies on time-consuming physical inspections to verify operator declarations and detect possible diversion of UF{sub 6}. Development of a reliable, automated, and tamper-resistant system for near real-time tracking and monitoring UF{sub 6} cylinders (as they move within an enrichment facility) would greatly improve the inspector function. This type of system can reduce the risk of false or misreported cylinder tare weights, diversion of nuclear material, concealment of excess production, utilization of undeclared cylinders, and misrepresentation of the cylinders contents. This paper will describe a proof-of-concept approach that was designed to evaluate the feasibility of using radio frequency (RF)-based technologies to track individual UF{sub 6} cylinders throughout a portion of their life cycle, and thus demonstrate the potential for improved domestic accountability of materials, and a more effective and efficient method for application of site-level IAEA safeguards. The evaluation system incorporates RF-based identification devices (RFID) which provide a foundation for establishing a reliable, automated, and near real-time tracking system that can be set up to utilize site-specific, rules-based detection algorithms. This paper will report results from a proof-of-concept demonstration at a real enrichment facility that is specifically designed to evaluate both the feasibility of using RF to track cylinders and the durability of the RF equipment to survive the rigors of operational processing and handling. The paper also discusses methods for securely attaching RF devices and describes how the technology can effectively be layered with other safeguard systems and approaches to build a robust system for detecting cylinder diversion. Additionally, concepts for off-site tracking of cylinders are described.

Pickett, Chris A [ORNL; Younkin, James R [ORNL; Kovacic, Donald N [ORNL; Laughter, Mark D [ORNL; Hines, Jairus B [ORNL; Boyer, Brian [Los Alamos National Laboratory (LANL); Martinez, B. [Los Alamos National Laboratory (LANL)

2008-01-01T23:59:59.000Z

415

Recommended plutonium release fractions from postulated fires. Final report  

Science Conference Proceedings (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

416

Fractionation of Boron Isotopes in Icelandic Hydrothermal Systems  

DOE Green Energy (OSTI)

Boron isotope ratios have been determined in a variety of different geothermal waters from hydrothermal systems across Iceland. Isotope ratios from the high temperature meteoric water recharged systems reflect the isotope ratio of the host rocks without any apparent fractionation. Seawater recharged geothermal systems exhibit more positive {delta}{sup 11}B values than the meteoric water recharged geothermal systems. Water/rock ratios can be assessed from boron isotope ratios in the saline hydrothermal systems. Low temperature hydrothermal systems also exhibit more positive {delta}{sup 11}B than the high temperature systems, indicating fractionation of boron due to adsorption of the lighter isotope onto secondary minerals. Fractionation of boron in carbonate deposits may indicate the level of equilibrium attained within the systems.

Aggarwal, J.K.; Palmer, M.R.

1995-01-01T23:59:59.000Z

417

Bulk-edge correspondence in fractional Chern insulators  

E-Print Network (OSTI)

It has been recently realized that strong interactions in topological Bloch bands give rise to the appearance of novel states of matter. Here we study connections between these systems -- fractional Chern insulators and the fractional quantum Hall states -- via generalization of a gauge-fixed Wannier-Qi construction in the cylinder geometry. Our setup offers a number of important advantages compared to the earlier exact diagonalization studies on a torus. Most notably, it gives access to edge states and to a single-cut orbital entanglement spectrum, hence to the physics of bulk-edge correspondence. It is also readily implemented in the state-of-the-art density matrix renormalisation group method that allows for numerical simulations of significantly larger systems. We demonstrate our general approach on examples of flat-band models on ruby and kagome lattices at bosonic filling fractions $\

Zhao Liu; D. L. Kovrizhin; Emil J. Bergholtz

2013-04-04T23:59:59.000Z

418

Fractional extensions of some boundary value problems in oil strata  

E-Print Network (OSTI)

In the present paper, we solve three boundary value problems related to the temperature field in oil strata -- the fractional extensions of the incomplete lumped formulation and lumped formulation in the linear case and the fractional generalization of the incomplete lumped formulation in the radial case. By using the Caputo differintegral operator and the Laplace transform, the solutions are obtained in integral forms where the integrand is expressed in terms of the convolution of some auxiliary functions of Wright function type. A generalization of the Laplace transform convolution theorem, known as Efros' theorem is widely used.

Garg, Mridula

2007-01-01T23:59:59.000Z

419

Effective Field Theory of Fractional Quantized Hall Nematics  

SciTech Connect

We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state wave function in the symmetry-broken phase. In such a state of matter, the Hall resistance remains quantized while the longitudinal DC resistivity due to thermally-excited quasiparticles is anisotropic. We interpret recent experiments at Landau level filling factor {nu} = 7/3 in terms of our theory.

Mulligan, Michael; /MIT, LNS; Nayak, Chetan; /Station Q, UCSB; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC

2012-06-06T23:59:59.000Z

420

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

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

Kinetic Isotopic Fractionation During Diffusion of Ionic Speciesin Water  

Science Conference Proceedings (OSTI)

Experiments specifically designed to measure the ratio of the diffusivities of ions dissolved in water were used to determine D{sub Li}/D{sub K}, D{sub 7{sub Li}}/D{sub 6{sub Li}}, D{sub 25{sub Mg}}/D{sub 24{sub Mg}}, D{sub 26{sub Mg}}/D{sub 25{sub Mg}}, and D{sub 37{sub Cl}}/D{sub 35{sub Cl}}. The measured ratio of the diffusion coefficients for Li and K in water (D{sub Li}/D{sub K} = 0.6) is in good agreement with published data, providing evidence that the experimental design being used resolves the relative mobility of ions with adequate precision to also be used for determining the fractionation of isotopes by diffusion in water. In the case of Li we found measurable isotopic fractionation associated with the diffusion of dissolved LiCl (D{sub 7{sub Li}}/D{sub 6{sub Li}} = 0.99772 {+-} 0.00026). This difference in the diffusion coefficient of {sup 7}Li compared to {sup 6}Li is significantly less than reported in an earlier study, a difference we attribute to the fact that in the earlier study Li diffused through a membrane separating the water reservoirs. Our experiments involving Mg diffusing in water found no measurable isotopic fractionation (D{sub 25{sub Mg}}/D{sub 24{sub Mg}} = 1.00003 {+-} 0.00006). Cl isotopes were fractionated during diffusion in water (D{sub 37{sub Cl}}/D{sub 35{sub Cl}} = 0.99857 {+-} 0.00080) whether or not the co-diffuser (Li or Mg) was isotopically fractionated. The isotopic fractionation associated with the diffusion of ions in water is much smaller than values we found previously for the isotopic fractionation of Li and Ca isotopes by diffusion in molten silicate liquids. A major distinction between water and silicate liquids is that water, being a polar liquid, surrounds dissolved ions with hydration shells, which very likely play an important but still poorly understood role in reducing isotopic fractionation associated with diffusion.

Richter, Frank M.; Mendybaev, Ruslan A.; Christensen, John; Hutcheon, Ian D.; Williams, Ross W.; Sturchio, Neil C.; Beloso Jr.,Abelardo D.

2005-06-09T23:59:59.000Z

422

Practical Guide to Vegetable Oil ProcessingChapter 10 Winterization and Fractionation  

Science Conference Proceedings (OSTI)

Practical Guide to Vegetable Oil Processing Chapter 10 Winterization and Fractionation Processing eChapters Processing Press Downloadable pdf of Chapter 10 Winterization and Fractionation from the book ...

423

FMC·RF'2a U.S. DEPARTlVIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

424

Conceptual Design for Replacement of the DTL and CCL with Superconducting RF Cavities in the Spallation Neutron Source Linac  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source Linac utilizes normal conducting RF cavities in the low energy section from 2.5 MeV to 186 MeV. Six Drift Tube Linac (DTL) structures accelerate the beam to 87 MeV, and four Coupled Cavity Linac (CCL) structures provide further acceleration to 186 MeV. The remainder of the Linac is comprised of 81 superconducting cavities packaged in 23 cryomodules to provide final beam energy of approximately 1 GeV. The superconducting Linac has proven to be substantially more reliable than the normal conducting Linac despite the greater number of stations and the complexity associated with the cryogenic plant and distribution. A conceptual design has been initiated on a replacement of the DTL and CCL with superconducting RF cavities. The motivation, constraints, and conceptual design are presented.

Champion, Mark S [ORNL; Doleans, Marc [ORNL; Kim, Sang-Ho [ORNL

2013-01-01T23:59:59.000Z

425

Role of Outer Membrane C-Type Cytochromes MtrC and OmcA in Shewanella Oneidensis MR-1 Cell Production, Accumulation, and Detachment During Respiration on Hematite  

Science Conference Proceedings (OSTI)

Solid phase iron oxides are considered to be important terminal electron acceptors for microbial respiration in many anoxic environments. Besides the knowledge that cells attach to and reduce these substrates, other aspects of surface-associated cell behavior and the related cell surface components that influence cell-mineral interactions are not well understood. In the present study, wild-type cells of the dissimilatory iron-reducing bacterium Shewanella oneidensis MR-1 formed thin biofilms one-to-two cell layers in thickness when respiring on natural specular hematite under flow conditions similar to those which exist in aquatic sediments and subsurface environments. The distribution of cells within the biofilm indicated that direct contact was not required for electron transfer from cells to the mineral surface. Detached biomass in the form of single cells represented >99% of the surface-associated wild-type cell production from respiration on hematite over the biofilm life cycle. A mutant deficient in the outer membrane c35 type cytochrome OmcA, while still able to respire and replicate on hematite, established a lower steady-state cell density on the mineral surface than that of the wild-type strain. A mutant deficient in MtrC, another outer membrane c-type cytochrome, and a mutant deficient in both cytochromes were unable to reduce sufficient amounts of hematite to support detectable growth on the mineral surface. When considered in the context of previous work, the results support a growing body of evidence that the relative importance of OmcA and MtrC to cell respiration and replication depends on the form of iron oxide available as terminal electron acceptor.

Mitchell, Andrew C.; Peterson, L.; Reardon, Catherine L.; Reed, Samantha B.; Culley, David E.; Romine, Margaret F.; Geesey, Gill G.

2012-07-01T23:59:59.000Z

426

Stray RF Power Estimates From EC Exploitation During ITER Plasma Operations  

SciTech Connect

The EC H and CD system of ITER tokamak is an essential tool for all the phases of ITER operation. Different levels of EC power are required through all the plasma discharge: up to 6.7 MW for assisting the breakdown and burn through, up to 20 MW for current drive and saw-teeth control from the equatorial launcher and up to 20 MW for NTM stabilization from the upper launchers. The assistance to breakdown and burn through is characterized by a very low (if not negligible) RF power absorption by the plasma. A significant level of stray radiation may also arise from partial absorption due to non-optimal plasma parameters and/or wrong injected polarization. The stray power radiated in the vacuum chamber is estimated as a first step toward mitigating potential harmful consequence to in-vessel structures and diagnostics. Power loading of the chamber walls (peek power and average power density for straight beam propagation in the empty chamber) and diffuse stray radiation effects are simulated to infer suitable strategies to avoid damage to first wall and to microwave sensitive components.

Gandini, F.; Henderson, M.; Darbos, C.; Gassmann, T.; Purohit, D.; Omori, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Nazare, C. [Assystem Facilities, 78067 Saint Quentin en Yvelines Cedex (France)

2011-12-23T23:59:59.000Z

427

Wakefield and RF Kicks Due to Coupler Asymmetry in TESLA-Type Accelerating Cavities  

SciTech Connect

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm.

Bane, K.L.F.; Adolphsen, C.; Li, Z.; /SLAC; Dohlus, M.; Zagorodnov, I.; /DESY; Gonin, I.; Lunin, A.; Solyak, N.; Yakovlev, V.; /Fermilab; Gjonaj, E.; Weiland, T.; /Darmstadt, Tech. Hochsch.

2008-07-07T23:59:59.000Z

428

Growth of TiO{sub 2} Thin Film on Various Substrates using RF Magnetron Sputtering  

Science Conference Proceedings (OSTI)

The conductivity of Titanium Dioxide (TiO{sub 2}) thin film fabricated using Radio Frequency (RF) Magnetron Sputtering on Silicon (Si), Indium doped--Tin Oxide (ITO) and microscope glass (M) substrates is presented in this paper. The dependant of thin film thickness and type of substrate been discussed. TiO{sub 2} was deposited using Ti target in Ar+O{sub 2}(45:10) mixture at 250 W for 45, 60, 75, 90, 105 and 120 minute. Resultant thickness varies from 295 nm to 724 nm with deposition rate 6.4 nm/min. On the other hand, resistivity, Rs value for ITO substrate is between 5.72x10{sup -7} to 1.54x10{sup -6{Omega}}.m, Si substrate range is between 3.52x10{sup -6} to 1.76x10{sup -5{Omega}}.m and M substrate range is between 99 to 332 {Omega}.m. The value of resistivity increases with the thickness of the thin film.

Ali, Riyaz Ahmad Mohamed; Nayan, Nafarizal [Microelectronic and Nanotechnology-Shamsuddin Research Center (MiNT-SRC), Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), 86400 Batu Pahat, Johor D.T. (Malaysia)

2011-03-30T23:59:59.000Z

429

Design of compact frequency synthesizer for self-calibration in RF circuits  

E-Print Network (OSTI)

A compact frequency synthesizer based on a phase locked loop (PLL) is designed for the self-calibration in RF circuits. The main advantage of the presented frequency synthesizer is that it can be built in a small silicon area using MOSFET interface trap charge pump (ITCP) current generators. The ITCP current generator makes it possible to use small currents at nano-ampere levels so that small capacitances can be used in the loop filter. A large resistance, which is required to compensate for the reduced capacitances, is implemented using an operational transconductance amplifier (OTA). An ITCP current generator is used as a tail current source for the OTA in order to realize a small transconductance. The presented frequency synthesizer has the output frequency range from 570 MHz to 600 MHz with a 100 KHz frequency step. Total silicon area is about 0.3 mm2 using AMIS 0.5 ??m CMOS technology, and the power consumption is 26.7 mW with 3 V single power supply.

Park, Sanghoon

2004-08-01T23:59:59.000Z

430

Implementation of longitudinal dynamics with barrier RF in BETACOOL and comparison to ESME  

Science Conference Proceedings (OSTI)

The barrier bucket RF system is successfully used on Recycler storage ring at Fermilab. The special program code ESME was used for numerical simulation of longitudinal phase space manipulations. This program helps optimizing the various regimes of operation in the Recycler and increasing the luminosity in the colliding experiments. Electron and stochastic cooling increases the phase space density in all degrees of freedom. In the case of a small phase space volume the intrabeam scattering introduces coupling between the transverse and longitudinal temperatures of the antiproton beam. For numerical simulations of the cooling processes at the Recycler, a new model of the barrier buckets was implemented in the BETACOOL code. The comparison between ESME and BETACOOL codes for a stationary and moving barrier buckets is presented. This article also includes an application of the barrier bucket numerical model for simulation of the luminosity distribution for RHIC colliding experiments. These simulations take into account the specific longitudinal distribution of the bunch and the vertex size of the detector.

Smirnov, A.; Fedotov, A.; Sidorin, A.; Krestnikov, D.; Bhat, C.; Prost, L.

2009-08-31T23:59:59.000Z

431

RF-THERMAL COMBINED SIMULATIONS OF A SUPERCONDUCTING HOM COAXIAL COUPLER  

Science Conference Proceedings (OSTI)

To benchmark a multi-physics code VORPAL developed by Tech-X, the High Order Mode (HOM) coaxial coupler design implemented in Jefferson Lab?s 12GeV upgrade cryomodules is analyzed by use of commercial codes, such as ANSYS, HFSS and Microwave Studio. Testing data from a Horizontal Test Bench (HTB) experiment on a dual-cavity prototype are also utilized in the verification of simulation results. The work includes two stages: first, the HOM feedthrough that has a high RRR niobium probe and sapphire insulator is analyzed for the RF-thermal response when there is travelling wave passing through; second, the HTB testing condition is simulated and results from simulation are compared to thermal measurements from HTB tests. The analyses are of coupled-field nature and involve highly nonlinear temperature dependent thermal conductivities and electric resistivities for the eight types of materials used in the design. Accuracy and efficiency are the main factors in evaluation of the performance of the codes.

Guangfeng Cheng, Haipeng Wang, David Smithe

2011-09-01T23:59:59.000Z

432

Disk-loaded RF waveguide matching techniques applied to silicon woodpile accelerator  

SciTech Connect

Silicon woodpile photonic crystal provides a three-dimensional dielectric waveguide system for high-gradient laser driven acceleration. The woodpile waveguide is periodically loaded in the longitudinal direction; therefore simple cross-sectional mode profile matching is not sufficient to launch the accelerating mode appropriately and will result in significant scattering loss. Hinted by the common nature of longitudinal periodicity between disk-loaded waveguide and woodpile waveguide, several coupler design schemes developed for multi-cell RF cavity are implemented in the woodpile accelerator design. Among them there are the travelling-wave match method based on S-matrix, the periodic VSWR method, and the TE-to-TM coupling iris design. This paper presents design procedures and simulation results using these methods. According to simulations, nearly 100% power transmission between SOI and woodpile waveguides with a travelling-wave match is achieved with a specially designed mode-launching coupler. Constructed by silicon rods extruding into the defect waveguide, the coupling iris provides necessary transition from TE mode to TM accelerating mode, also with negligible coupling loss.

Wu Ziran; England, Joel; Ng, Cho; Tantawi, Sami [Stanford Linear Accelerator National Laboratory 2575 Sand Hill Road, Menlo Park, CA 95051 (United States)

2012-12-21T23:59:59.000Z

433

Rf phase measurement at PHERMEX (Pulsed High Energy Radiographic Machine Emitting X-Rays) using time-to-digital converters  

Science Conference Proceedings (OSTI)

Recent advances in time-to-digital converters (TDCs) have made 50-MHz rf phase measurement possible without the use of double-balanced mixers. These advances allow zero crossing discriminators to be used in conjunction with fast CAMAC TDCs to make amplitude-independent phase measurements. This method uses a time interval proportional to the phase angle, thus eliminating any of the calculations and calibration required with double-balanced mixers. 4 refs., 1 fig., 1 tab.

Watson, S.A.; Jennings, G.R.; Moir, D.C.

1989-01-01T23:59:59.000Z

434

Anomalous Quantum Interference Induced by Landau-Zener Transitions in a Strongly Driven rf-SQUID Qubit  

E-Print Network (OSTI)

We irradiated an rf-SQUID qubit with large-amplitude and high frequency electromagnetic field. Population transitions between macroscopic distinctive quantum states due to Landau-Zener transitions at energy-level avoided crossings were observed. The qubit population on the excited states as a function of flux detuning and microwave power exhibits interference patterns. Some novel features are found in the interference and a model based on rate equations can well address the features.

Wang, Yiwen; Wen, Xueda; Pan, Cheng; Sun, Guozhu; Chen, Jian; Kang, Lin; Xu, Weiwei; Yu, Yang; Wu, Peiheng

2009-01-01T23:59:59.000Z

435

A "Proof-of-Concept" Demonstration of RF-Based Technologies for UF6 Cylinder Tracking at Centrifuge Enrichment Plant  

SciTech Connect

This effort describes how radio-frequency (RF) technology can be integrated into a uranium enrichment facility's nuclear materials accounting and control program to enhance uranium hexafluoride (UF6) cylinder tracking and thus provide benefits to both domestic and international safeguards. Approved industry-standard cylinders are used to handle and store UF6 feed, product, tails, and samples at uranium enrichment plants. In the international arena, the International Atomic Energy Agency (IAEA) relies on time-consuming manual cylinder inventory and tracking techniques to verify operator declarations and to detect potential diversion of UF6. Development of a reliable, automated, and tamper-resistant process for tracking and monitoring UF6 cylinders would greatly reduce the risk of false or misreported cylinder tare weights, diversion of nuclear material, concealment of excess production, utilization of undeclared cylinders, and misrepresentation of the cylinders contents. This paper will describe a "proof-of concept" system that was designed show the feasibility of using RF based technologies to track individual UF6 cylinders throughout their entire life cycle, and thus ensure both increased domestic accountability of materials and a more effective and efficient method for application of IAEA international safeguards at the site level. The proposed system incorporates RF-based identification devices, which provide a mechanism for a reliable, automated, and tamper-resistant tracking network. We explore how securely attached RF tags can be integrated with other safeguards technologies to better detect diversion of cylinders. The tracking system could also provide a foundation for integration of other types of safeguards that would further enhance detection of undeclared activities.

Pickett, Chris A [ORNL; Younkin, James R [ORNL; Kovacic, Donald N [ORNL; Dixon, E. T. [Los Alamos National Laboratory (LANL); Martinez, B. [Los Alamos National Laboratory (LANL)

2007-01-01T23:59:59.000Z

436

Time dependant quantum efficiency and dark current measurements in an RF photocathode injector with a high quantum efficiency cathode  

SciTech Connect

Studies of photo-emission and field emission behavior in an RF gun have been carried out. Unexpected phenomena were observed. In situ changes in the cathode's quantum efficiency and dark current with time were seen during operation of the photo-injector. These changes were correlated with the magnetostatic field at the cathode. In addition, multipacting has been observed under certain conditions. Recent measurements indicate a correlation between multipacting and anomalous photo- and field emission behavior.

Fliller, R.P., III; Edwards, H.; /Fermilab; Hartung, W.; /Michigan State U., NSCL

2005-05-01T23:59:59.000Z

437

Effect of annealing on the structural, optical and electrical properties of ITO films by RF sputtering under low vacuum level  

Science Conference Proceedings (OSTI)

Indium tin oxide (ITO) thin films were prepared by RF sputtering of ceramic ITO target in pure argon atmosphere at a high base pressure of 3x10^-^4mbar without substrate heating and oxygen admittance. The use of pure argon during deposition resulted ... Keywords: 68.55.J, 73.61.Le, 78.66.Li, 81.15.Cd, Annealing, Electrical properties, Indium tin oxide (ITO), Optical properties, Sputtering, X-ray diffraction

T. S. Sathiaraj

2008-12-01T23:59:59.000Z

438

Electron bunch energy and phase feed-forward stabilization system for the Mark V RF-linac free-electron laser  

SciTech Connect

An amplitude and phase compensation system has been developed and tested at the University of Hawai'i for the optimization of the RF drive system to the Mark V free-electron laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.

Hadmack, M. R.; Kowalczyk, J. M. D.; Lienert, B. R.; Madey, J. M. J.; Szarmes, E. B. [Department of Physics and Astronomy, University of Hawai'i at Manoa, Honolulu, Hawaii 96822 (United States); Jacobson, B. T. [RadiaBeam Technologies, Santa Monica, California 90404 (United States)

2013-06-15T23:59:59.000Z

439

Optical Properties of Zn(O,S) Thin Films Deposited by RF Sputtering, Atomic Layer Deposition, and Chemical Bath Deposition: Preprint  

DOE Green Energy (OSTI)

Zn(O,S) thin films 27 - 100 nm thick were deposited on glass or Cu(InxGa1-x)Se2/Molybdenum/glass with RF sputtering, atomic layer deposition, and chemical bath deposition.

Li, J.; Glynn, S.; Christensen, S.; Mann, J.; To, B.; Ramanathan, K.; Noufi, R.; Furtak, T. E.; Levi, D.

2012-06-01T23:59:59.000Z

440

Electron bunch energy and phase feed-forward stabilization system for the Mark V RF-linac free-electron laser  

E-Print Network (OSTI)

An amplitude and phase compensation system has been developed and tested at the University of Hawai`i for the optimization of the RF drive system to the Mark V Free-Electron Laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.

Hadmack, M R; Kowalczyk, J M D; Lienert, B R; Madey, J M J; Szarmes, E B

2013-01-01T23:59:59.000Z

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441

Photocathode emission studies: Dark current and Schottky-enabled photo-electrons in a high-field RF gun  

Science Conference Proceedings (OSTI)

We report on dark current and Schottky-enabled photoemission from a copper photocathode surface. Field-emitted dark current is a major gradient-limiting factor in RF cavities. Field emission is generally attributed to geometrical projections on the bulk surface whose field enhancement factor ({beta}) and the emitting area (A{sub e}) can be extracted from the Fowler-Nordheim (FN) plot. Measurements were made at Tsinghua S-band RF gun facility in two separate experiments. Using the traditional FN formula for RF fields we discovered that field enhancement factor ({beta}) alone cannot explain the full data set. Instead, we found that a low work function at some sites is required. In addition, surface analysis of the cathode after the experiment shows that geometric {beta} indicated would be < 10. Thus we conclude that low work function sites with a small {beta} are responsible for dark current emission and subsequent breakdown in high-gradient structures. The origin of these sites is unclear but could be due to defects or impurities.

Chen, H.; Du, Y.; Gai, W.; Grudiev, A.; Hua, J.; Huang, W.; Power, J.; Wisniewski, E. E.; Wuensch, W.; Tang, C.; Yan, L.; You, Y. [Dept. of Eng. Phys., Tsinghua U. (China); ANL/HEP, Argonne, IL (United States); CERN, Geneva (Switzerland); Dept. of Eng. Phys., Tsinghua U. (China); ANL/HEP, Argonne, IL (United States); ANL/HEP, Argonne, IL (United States) and IIT Chicago, IL (United States); CERN, Geneva (Switzerland); Dept. of Eng. Phys., Tsinghua U. (China)

2012-12-21T23:59:59.000Z

442

Optical transformation from chirplet to fractional Fourier transformation kernel  

E-Print Network (OSTI)

We find a new integration transformation which can convert a chirplet function to fractional Fourier transformation kernel, this new transformation is invertible and obeys Parseval theorem. Under this transformation a new relationship between a phase space function and its Weyl-Wigner quantum correspondence operator is revealed.

Hong-yi Fan; Li-yun Hu

2009-02-11T23:59:59.000Z

443

Optical transformation from chirplet to fractional Fourier transformation kernel  

E-Print Network (OSTI)

We find a new integration transformation which can convert a chirplet function to fractional Fourier transformation kernel, this new transformation is invertible and obeys Parseval theorem. Under this transformation a new relationship between a phase space function and its Weyl-Wigner quantum correspondence operator is revealed.

Fan, Hong-yi

2009-01-01T23:59:59.000Z

444

Dynamic frequency allocation in fractional frequency reused OFDMA networks  

Science Conference Proceedings (OSTI)

This paper proposes a dynamic fractional frequency reused cell architecture that simplifies the problem of subcarrier allocation with frequency reuse in multicell OFDMA networks. The architecture divides the cell surface into two overlapping geographical ... Keywords: 3G, cellular networks, cross-layer adaptation, data networks, mobile communication systems, opportunistic scheduling, wireless communication

Syed Hussain Ali; Victor C. M. Leung

2009-08-01T23:59:59.000Z

445

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

E-Print Network (OSTI)

theory and solution methods for various types of fractional programs. ... many industries including airlines, energy, manufacturing and telecommunications. .... model is used by hospital administrators in the State of Texas to decide on relative ... matrix. The i th deterministic constraint for (2.2) is obtained from [7-11] as. ?. = n.

446

Anaerobic digestion of the liquid fraction of dairy manure  

Science Conference Proceedings (OSTI)

The authors tested several solid liquid separation systems suitable for processing dairy manure prior to anaerobic digestion. None of the systems tried have completely satisfied the requirements. Evaluated effects of separation on biogas production. Unseparated dairy manure produced more biogas than the liquid fraction.

Haugen, V.; Dahlberg, S.; Lindley, J.A.

1983-06-01T23:59:59.000Z

447

Process for removing polymer-forming impurities from naphtha fraction  

DOE Patents (OSTI)

Polymer precursor materials are vaporized without polymerization or are removed from a raw naphtha fraction by passing the raw naphtha to a vaporization zone and vaporizing the naphtha in the presence of a wash oil while stripping with hot hydrogen to prevent polymer deposits in the equipment. 2 figs.

Kowalczyk, D.C.; Bricklemyer, B.A.; Svoboda, J.J.

1983-12-27T23:59:59.000Z

448

Process for removing polymer-forming impurities from naphtha fraction  

DOE Patents (OSTI)

Polymer precursor materials are vaporized without polymerization or are removed from a raw naphtha fraction by passing the raw naphtha to a vaporization zone (24) and vaporizing the naphtha in the presence of a wash oil while stripping with hot hydrogen to prevent polymer deposits in the equipment.

Kowalczyk, Dennis C. (Pittsburgh, PA); Bricklemyer, Bruce A. (Avonmore, PA); Svoboda, Joseph J. (Pittsburgh, PA)

1983-01-01T23:59:59.000Z

449

Examination of sharing fractions for prices and quantities  

Science Conference Proceedings (OSTI)

When the Household Model of Energy (HOME) and Commercial Sector Energy Model (CSEM) are run as modules in the Intermediate Future Forecasting System (IFFS), the interfacing variables (prices and consumption of fuels) have to be adjusted to their aggregated regional levels. Both HOME and CSEM operate at a level of 4 Census Regions whereas IFFS uses 10 federal Regions. This makes it necessary to aggregate the prices provided by IFFS to the 4 Census Regions and to disaggregate the sectoral consumption values calculated by HOME and CSEM to the 10 federal Regions. An examination of the historical fractions for consumption levels and prices by fuels and sectors (residential and commercial) was performed to substantiate the assumption that changes of these fractions over time are not significant. This assumption is presently employed in both HOME and CSEM. The fractions which are presently used were calculated for each fuel based on the consumption data for the year 1980. These fractions, once evaluated, are used for sharing both prices and consumption throughout the forecasting period.

Meyer, M.

1986-02-01T23:59:59.000Z

450

Technical Standards, DOE-HDBK-3010-94- March 22, 2000  

Energy.gov (U.S. Department of Energy (DOE))

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

451

Development of bellows and gate valves with a comb-type rf shield for high-current accelerators: Four-year beam test at KEK B-Factory  

SciTech Connect

Since a comb-type rf shield was proposed in 2003 as a rf shield for future high-intensity accelerators, various types of bellow chambers and gate valves with this rf shield have been installed in the KEK B-Factory rings in series and tested with beams. Through beam tests to check the performance, a structural simplification has been tried in parallel. The temperatures of the bellow corrugations decreased by a factor of 3-6 compared to those with a conventional finger-type rf shield in most cases. The temperatures of the body of the gate valves also decreased by a factor of 2-5. These results demonstrated the availability of the comb-type rf shield. Although a discharge was observed in one simplified model, the latest model has shown no problem up to a stored beam current of 1.8 A (1.3 mA/bunch, 6 mm bunch length). Experiences with the comb-type rf shield in these four-year beam tests are reviewed here.

Suetsugu, Yusuke; Kanazawa, Ken-ichi; Shibata, Kyo; Shirai, Mitsuru; Bondar, Aleksander E.; Kuzminykh, Victor S.; Gorbovsky, Aleksander I.; Sonderegger, Kurt; Morii, Minoru; Kawada, Kakuyu [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Budker Institute of Nuclear Physics (BINP), Novosibirsk 630090 (Russian Federation); VAT Vakuumventile AG, Haag CH-9469 (Switzerland); VAT SKK Vacuum Ltd., Yokohama, Kanagawa 240-0023 (Japan)

2007-04-15T23:59:59.000Z

452

FRACTIONATION OF LIGNOCELLULOSIC BIOMASS FOR FUEL-GRADE ETHANOL PRODUCTION  

SciTech Connect

PureVision Technology, Inc. (PureVision) of Fort Lupton, Colorado is developing a process for the conversion of lignocellulosic biomass into fuel-grade ethanol and specialty chemicals in order to enhance national energy security, rural economies, and environmental quality. Lignocellulosic-containing plants are those types of biomass that include wood, agricultural residues, and paper wastes. Lignocellulose is composed of the biopolymers cellulose, hemicellulose, and lignin. Cellulose, a polymer of glucose, is the component in lignocellulose that has potential for the production of fuel-grade ethanol by direct fermentation of the glucose. However, enzymatic hydrolysis of lignocellulose and raw cellulose into glucose is hindered by the presence of lignin. The cellulase enzyme, which hydrolyzes cellulose to glucose, becomes irreversibly bound to lignin. This requires using the enzyme in reagent quantities rather than in catalytic concentration. The extensive use of this enzyme is expensive and adversely affects the economics of ethanol production. PureVision has approached this problem by developing a biomass fractionator to pretreat the lignocellulose to yield a highly pure cellulose fraction. The biomass fractionator is based on sequentially treating the biomass with hot water, hot alkaline solutions, and polishing the cellulose fraction with a wet alkaline oxidation step. In September 2001 PureVision and Western Research Institute (WRI) initiated a jointly sponsored research project with the U.S. Department of Energy (DOE) to evaluate their pretreatment technology, develop an understanding of the chemistry, and provide the data required to design and fabricate a one- to two-ton/day pilot-scale unit. The efforts during the first year of this program completed the design, fabrication, and shakedown of a bench-scale reactor system and evaluated the fractionation of corn stover. The results from the evaluation of corn stover have shown that water hydrolysis prior to alkaline hydrolysis may be beneficial in removing hemicellulose and lignin from the feedstock. In addition, alkaline hydrolysis has been shown to remove a significant portion of the hemicellulose and lignin. The resulting cellulose can be exposed to a finishing step with wet alkaline oxidation to remove the remaining lignin. The final product is a highly pure cellulose fraction containing less than 1% of the native lignin with an overall yield in excess of 85% of the native cellulose. This report summarizes the results from the first year's effort to move the technology to commercialization.

F.D. Guffey; R.C. Wingerson

2002-10-01T23:59:59.000Z

453

Silicon Isotopic Fractionation of CAI-like Vacuum Evaporation Residues  

SciTech Connect

Calcium-, aluminum-rich inclusions (CAIs) are often enriched in the heavy isotopes of magnesium and silicon relative to bulk solar system materials. It is likely that these isotopic enrichments resulted from evaporative mass loss of magnesium and silicon from early solar system condensates while they were molten during one or more high-temperature reheating events. Quantitative interpretation of these enrichments requires laboratory determinations of the evaporation kinetics and associated isotopic fractionation effects for these elements. The experimental data for the kinetics of evaporation of magnesium and silicon and the evaporative isotopic fractionation of magnesium is reasonably complete for Type B CAI liquids (Richter et al., 2002, 2007a). However, the isotopic fractionation factor for silicon evaporating from such liquids has not been as extensively studied. Here we report new ion microprobe silicon isotopic measurements of residual glass from partial evaporation of Type B CAI liquids into vacuum. The silicon isotopic fractionation is reported as a kinetic fractionation factor, {alpha}{sub Si}, corresponding to the ratio of the silicon isotopic composition of the evaporation flux to that of the residual silicate liquid. For CAI-like melts, we find that {alpha}{sub Si} = 0.98985 {+-} 0.00044 (2{sigma}) for {sup 29}Si/{sup 28}Si with no resolvable variation with temperature over the temperature range of the experiments, 1600-1900 C. This value is different from what has been reported for evaporation of liquid Mg{sub 2}SiO{sub 4} (Davis et al., 1990) and of a melt with CI chondritic proportions of the major elements (Wang et al., 2001). There appears to be some compositional control on {alpha}{sub Si}, whereas no compositional effects have been reported for {alpha}{sub Mg}. We use the values of {alpha}Si and {alpha}Mg, to calculate the chemical compositions of the unevaporated precursors of a number of isotopically fractionated CAIs from CV chondrites whose chemical compositions and magnesium and silicon isotopic compositions have been previously measured.

Knight, K; Kita, N; Mendybaev, R; Richter, F; Davis, A; Valley, J

2009-06-18T23:59:59.000Z

454

the Fractional Flotation of Flotation Column Particles Opportunity  

NLE Websites -- All DOE Office Websites (Extended Search)

Enhancing Selectivity and Recovery in Enhancing Selectivity and Recovery in the Fractional Flotation of Flotation Column Particles Opportunity Although research is currently inactive on the patented technology "Method for Enhancing Selectivity and Recovery in the Fractional Flotation of Flotation Column Particles," the technology is available for licensing from the U.S. Department of Energy's National Energy Technology Laboratory (NETL). Disclosed in this patent is a method of particle separation from a feed stream comprised of particles of varying hydrophobicity by injecting the feed stream directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. The current invention allows the height of the feed stream injection and the reflux ratio to be

455

Magic Doping Fractions in High-Temperature Superconductors  

Science Conference Proceedings (OSTI)

We report hole-doping dependence of the in-plane resistivity {rho}{sub ab} in a cuprate superconductor La{sub 2-x}Sr{sub x}CuO{sub 4}, carefully examined using a series of high-quality single crystals. Our detailed measurements find a tendency towards charge ordering at particular rational hole doping fractions of 1/16, 3/32, 1/8, and 3/16. This observation appears to suggest a specific form of charge order and is most consistent with the recent theoretical prediction of the checkerboard-type ordering of the Cooper pairs at rational doping fractions x = (2m + 1)/2{sup n}, with integers m and n.

Komiya, Seiki; /CRIEPI, Tokyo; Chen, Han-Dong; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.; Ando, Yoichi; /CRIEPI, Tokyo

2010-01-15T23