National Library of Energy BETA

Sample records for rf respirable fraction

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

    SciTech Connect (OSTI)

    Not Available

    1994-12-01

    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.

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

    E-Print Network [OSTI]

    Rue, Clayton Matthew

    1981-01-01

    terms of the particulate matter which passes through separators with aerodynamic cutpoint sizes of 10 and 2. 5 um, respect- ively. The system is des1gned to operate at a flowrate of 113 L/min (4, 0 . cfm) with the flow split into two equal parts. A... for stripp1ng the non-RSP aerosol from the distribut1on. The cyclone separator has a cutpo1nt of 2. 5 + 0. 3 um with the penetra- t1on curve hav1ng a slope of 1. 26. The latter fraction conta1ning the RSP particles is then drawn through a second collect1on...

  3. RF-driven Proton Source with a Back-streaming Electron Dump

    E-Print Network [OSTI]

    Ji, Q.

    2010-01-01

    RESULTS A. Atomic ion fraction for RF power above 500 W. AtI, the atomic ion fraction increases with the RF power, and

  4. Microbial respiration measurements Microbial respiration is a key process in the carbon cycling

    E-Print Network [OSTI]

    and energy to the microbial as- semblage. We estimated that DMSP can satisfy 20-67% of the bacterial sulfur8 Highlight Microbial respiration measurements Microbial respiration is a key process in the carbon from the rest of the microbial community by means of size- fractionation, and long incubation times

  5. University of Rochester Respirator Training

    E-Print Network [OSTI]

    Cantlon, Jessica F.

    and seal checks Maintenance and storage Symptoms of a malfunctioning respirator General requirements that cartridges will filter · e.g. yellow = organic vapors · green = ammonia UofR Respirator Training 13 #12

  6. Recycler barrier RF buckets

    SciTech Connect (OSTI)

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  7. Fabrication of microfluidic devices for artificial respiration

    E-Print Network [OSTI]

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

    2007-01-01

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

  8. Rf Feedback free electron laser

    DOE Patents [OSTI]

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

    1981-01-01

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

  9. Shielded RF Lattice Chris Rogers,

    E-Print Network [OSTI]

    McDonald, Kirk

    Shielded RF Lattice Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12;Shielded RF Status Shielded RF Lattice was developed until ~ April 2010 April make the same decision for RDR Time to dust the design off #12;Shielded RF - Reminder Increase cell

  10. Commercial SNF Accident Release Fractions

    SciTech Connect (OSTI)

    J. Schulz

    2004-11-05

    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.

  11. Rf2a and rf2b transcription factors

    DOE Patents [OSTI]

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

    2007-10-02

    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.

  12. RF test bench automation Description

    E-Print Network [OSTI]

    Dobigeon, Nicolas

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

  13. Operating Experience Level 3: Radiologically Contaminated Respirators...

    Energy Savers [EERE]

    Experience Level 3 provides information on a safety concern related to radiological contamination of launderedreconditioned respirators and parts that have been certified as...

  14. Racetrack microtron rf system

    SciTech Connect (OSTI)

    Tallerico, P.J.; Keffeler, D.R.

    1985-01-01

    The rf system for the National Bureau of Standards (NBS)/Los Alamos cw racetrack microtron is described. The low-power portion consists of five 75-W amplifers that drive two input ports in each of two chopper deflection cavities and one port in the prebuncher cavity. A single 500-kW klystron drives four separate 2380-MHz cavity sections: the two main accelerator sections, a capture section, and a preaccelerator section. The phases and amplitudes in all cavities are controlled by electronic or electromechanical controls. The 1-MW klystron power supply and crowbar system were purchased as a unit; several modifications are described that improve power-supply performance. The entire rf system has been tested and shipped to the NBS, and the chopper-buncher system has been operated with beam at the NBS. 5 refs., 2 figs.

  15. Respirators for Pesticide Applications1 Frederick M. Fishel2

    E-Print Network [OSTI]

    Hill, Jeffrey E.

    respirators only (100 series filters) · TC-23C: chemical cartridge respirators · TC-14G: gas masks such as dusts and mists. Newer pesticide labels that specify organic vapor-removing cartridge respirators, once

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De p u t y A sCOLONYDepartment of EnergyDepartment TS NOT

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p a l De p u t y A sCOLONYDepartment of EnergyDepartment TS NOT TS

  18. Ion source with external RF antenna

    DOE Patents [OSTI]

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

    2005-12-13

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

  19. RF power generation

    E-Print Network [OSTI]

    Carter, R G

    2011-01-01

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

  20. Automated soil respiration measurements: new information, opportunities and challenges

    E-Print Network [OSTI]

    Vargas, R.; Carbone, M. S.

    2008-01-01

    information, opportunities, and challenges Automated Soil Respiration Workshop – a Terrestrial Ecosystem

  1. RF breakdown experiments at SLAC

    SciTech Connect (OSTI)

    Laurent, L. [University of California Davis, Davis, California 95616 (United States); Vlieks, A.; Pearson, C.; Caryotakis, G.; Luhmann, N.C. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States)

    1999-05-01

    RF breakdown is a critical issue in the conditioning of klystrons, accelerator sections, and rf components for the next linear collider (NLC), as well as other high gradient accelerators and high power microwave sources. SLAC is conducting a series of experiments using an X-band traveling wave ring to characterize the processes and trigger mechanisms associated with rf breakdown. The goal of the research is to identify materials, processes, and manufacturing methods that will increase the breakdown threshold and minimize the time required for conditioning. {copyright} {ital 1999 American Institute of Physics.}

  2. Unbalanced field RF electron gun

    DOE Patents [OSTI]

    Hofler, Alicia

    2013-11-12

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

  3. Intelligent Radio Frequency (RF) Monitoring 

    E-Print Network [OSTI]

    Kimbrough, B.

    2010-01-01

    ? Regulatory fines Location 8 ?Expect many enjoyable experiences!? David M. Armstrong Continuous RF Monitoring RELIEF VALVE MONITORING The solution?? 9 ?Expect many enjoyable experiences!? David M. Armstrong Continuous RF Monitoring TEMPERATURE...?Armstrong? WiHART?Device Non?Armstrong? WiHART?Device Non?Armstrong? WiHART?Device Open Mesh Wireless Structure STEAM TRAP MONITORING RELIEF VALVE MONITORING TEMPERATURE MONITORING GATEWAY 14 ?Expect many enjoyable experiences!? David M. Armstrong...

  4. June 2011 Page 1 of 3 Respirator Request Form

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    INDUSTRIAL HYGIENE ASSESSMENT 18. Respirator(s) Selected Half-Face cartridge Full-Face cartridge PAPR SCBA: Other (specify) Cartridge: Activities: 21. Reviewed Assessment with Supervisor (required) 22. Industrial

  5. Phase modulation in RF tag

    DOE Patents [OSTI]

    Carrender, Curtis Lee; Gilbert, Ronald W.

    2007-02-20

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

  6. Measurement of chlorite dismutase activities in perchlorate respiring bacteria

    E-Print Network [OSTI]

    Measurement of chlorite dismutase activities in perchlorate respiring bacteria Jianlin Xu*, Bruce E to chloride (ClO2 À ! ClÀ + O2) and is present in bacteria capable of cell respiration using perchlorate concentration (0.6 mM) to four other perchlorate respiring bacteria (PRB), and to one non-PRB (Pseudomonas

  7. Ion bombardment in RF photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V. N.

    2009-05-04

    A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.

  8. Cryogenic vacuumm RF feedthrough device

    DOE Patents [OSTI]

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

    2008-12-30

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

  9. Klystron equalization for RF feedback

    SciTech Connect (OSTI)

    Corredoura, P.

    1993-01-01

    The next generation of colliding beam storage rings support higher luminosities by significantly increasing the number of bunches and decreasing the spacing between respective bunches. The heavy beam loading requires large RF cavity detuning which drives several lower coupled bunch modes very strongly. One technique which has proven to be very successful in reducing the coupled bunch mode driving impedance is RF feedback around the klystron-cavity combination. The gain and bandwidth of the feedback loop is limited by the group delay around the feedback loop. Existing klystrons on the world market have not been optimized for this application and contribute a large portion of the total loop group delay. This paper describes a technique to reduce klystron group delay by adding an equalizing filter to the klystron RF drive. Such a filter was built and tested on a 500 kill klystron as part of the on going PEP-II R&D effort here at SLAC.

  10. Klystron equalization for RF feedback

    SciTech Connect (OSTI)

    Corredoura, P.

    1993-01-01

    The next generation of colliding beam storage rings support higher luminosities by significantly increasing the number of bunches and decreasing the spacing between respective bunches. The heavy beam loading requires large RF cavity detuning which drives several lower coupled bunch modes very strongly. One technique which has proven to be very successful in reducing the coupled bunch mode driving impedance is RF feedback around the klystron-cavity combination. The gain and bandwidth of the feedback loop is limited by the group delay around the feedback loop. Existing klystrons on the world market have not been optimized for this application and contribute a large portion of the total loop group delay. This paper describes a technique to reduce klystron group delay by adding an equalizing filter to the klystron RF drive. Such a filter was built and tested on a 500 kill klystron as part of the on going PEP-II R D effort here at SLAC.

  11. Negative ion source with external RF antenna

    DOE Patents [OSTI]

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

    2007-02-13

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

  12. Note on RF Photo-Cathode Gun

    E-Print Network [OSTI]

    Kim, Kwang-Je

    2010-01-01

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

  13. High-Power Rf Load

    DOE Patents [OSTI]

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

    1998-09-01

    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.

  14. The LHC Low Level RF

    E-Print Network [OSTI]

    Baudrenghien, Philippe; Molendijk, John Cornelis; Olsen, Ragnar; Rohlev, Anton; Rossi, Vittorio; Stellfeld, Donat; Valuch, Daniel; Wehrle, Urs

    2006-01-01

    The LHC RF consists of eight 400 MHz superconducting cavities per ring, with each cavity independently powered by a 300 kW klystron, via a circulator. The challenge for the Low Level is to cope with very high beam current (more than 1 A RF component) and achieve excellent beam lifetime (emittance growth time in excess of 25 hours). Each cavity has an associated Cavity Controller rack consisting of two VME crates which implement high gain RF Feedback, a Tuner Loop with a new algorithm, a Klystron Ripple Loop and a Conditioning system. In addition each ring has a Beam Control system (four VME crates) which includes a Frequency Program, Phase Loop, Radial Loop and Synchronization Loop. A Longitudinal Damper (dipole and quadrupole mode) acting via the 400 MHz cavities is included to reduce emittance blow-up due to filamentation from phase and energy errors at injection. Finally an RF Synchronization system implements the bunch into bucket transfer from the SPS into each LHC ring. When fully installed in 2007, the...

  15. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, Patrick H. (Rancho Palos Verdes, CA); Yu, David U. L. (Rancho Palos Verdes, CA)

    1995-01-01

    A digital-to analogue converter for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration.

  16. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, P.H.; Yu, D.U.L.

    1995-02-28

    A digital-to-analog converter is disclosed for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration. 18 figs.

  17. Introduction Final Cooling Channel -High Frequency RF

    E-Print Network [OSTI]

    McDonald, Kirk

    Outline Introduction Final Cooling Channel - High Frequency RF Muon Collider Final Cooling Hisham Sayed February 27, 2014 1 / 10 #12;Outline Introduction Final Cooling Channel - High Frequency RF Table of Contents 1 Introduction 2 Final Cooling Channel - High Frequency RF 2 / 10 #12;Outline Introduction Final

  18. BROADBAND LOW ACTUATIONVOLTAGE RF'MEM SWITCHES

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    (RF) Microelectromechanical (MEM) switches have been thought of as one of the most attractive devicesBROADBAND LOW ACTUATIONVOLTAGE RF'MEM SWITCHES Shyh-ChiangShen,David Caruth, and Milton Feng of Illinois at Urbana-Champaign,IL61801-2355 ABSTRACT- We demonstrate a sub-lovolts RF MEM switch built

  19. The SPEAR3 RF System

    SciTech Connect (OSTI)

    McIntosh, P.

    2005-01-18

    SPEAR2 was upgraded in 2003, to a new 3rd Generation Light Source (3GLS)-SPEAR3, enabling users to take better advantage of almost 100x higher brightness and flux density over its predecessor. As part of the upgrade, the SPEAR2 RF system has been revamped from its original configuration of one 200 kW klystron feeding a single 358.5 MHz, 5-cell aluminum cavity; to a 1.2 MW klystron feeding four 476.3 MHz, HOM damped copper cavities. The system installation was completed in late November 2003 and the required accelerating voltage of 3.2 MV (800 kV/cavity) was very rapidly achieved soon after. This paper details the SPEAR3 RF system configuration and its new operating requirements, highlighting its installation and subsequent successful operation.

  20. Low jitter RF distribution system

    DOE Patents [OSTI]

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

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

  1. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

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

    1981-02-11

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

  2. RF Processing Experience with the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Schmerge, J.F.

    2010-11-24

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. A total of five different metal cathodes (4 Cu and 1 Mg) have been installed on the GTF gun. The rf processing history with the different cathodes will be presented including peak field achieved at the cathode. The LCLS gun is intended to operate at 120 MV/m and fields up to 140 MV/m have been achieved in the GTF gun. After installing a new cathode the number of rf pulses required to reach 120 MV/m is approximately 5-10 million. Total emitted dark current and Fowler Nordheim plots are also shown over the life of the cathode. The GTF photo-injector gun is an S-band standing-wave structure, with two resonant cavities and an intervening thick washer (Figure 1). The flat, back wall of the first cavity is a copper plate that serves as photocathode when illuminated with ultraviolet light from a pulsed, high-power laser. RF power enters the gun through an iris on the outer wall of the second cavity, and is coupled to the first through the axial opening of the washer. The first cavity is often referred to as a half cell, because its full-cell length has been truncated by the cathode plate and the second cavity is called the full cell. The gun is designed to operate in a {pi} mode, with the peak field on axis in each cell approximately equal. The maximum in the half cell occurs at the cathode, and in the full cell near the center of the cavity. The field profile and tuning procedures are discussed in a separate tech note [1].

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

    DOE Patents [OSTI]

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

    2014-04-29

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

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

    E-Print Network [OSTI]

    Teskey, Robert O.

    in mean growing season temperature. This allowed us to determine whether net photosynthesis and dark the #12;rate and magnitude of temperature acclimation of net photosynthesis and dark respiration. After ten days of pre-treatment at 20o C, we measured rates of net photosynthesis (Anet), dark respiration

  5. RF power recovery feedback circulator

    DOE Patents [OSTI]

    Sharamentov, Sergey I. (Bolingbrook, IL)

    2011-03-29

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

  6. RF Power Generation in LHC

    E-Print Network [OSTI]

    Brunner, O C; Valuch, D

    2003-01-01

    The counter-rotating proton beams in the Large Hadron Collider (LHC) will be captured and then accelerated to their final energies of 2 x 7 TeV by two identical 400 MHz RF systems. The RF power source required for each beam comprises eight 300 kW klystrons. The output power of each klystron is fed via a circulator and a waveguide line to the input coupler of a single-cell super-conducting (SC) cavity. Four klystrons are powered by a 100 kV, 40A AC/DC power converter, previously used for the operation of the LEP klystrons. A five-gap thyratron crowbar protects the four klystrons in each of these units. The technical specification and measured performance of the various high-power elements are discussed. These include the 400MHz/300kW klystrons with emphasis on their group delay and the three-port circulators, which have to cope with peak reflected power levels up to twice the simultaneously applied incident power of 300 kW. In addition, a novel ferrite loaded waveguide absorber, used as termination for port No...

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

    National Nuclear Security Administration (NNSA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal GasAdministration Medal01 Sandia4) AugustA. Geographic Available for® ALOHA A RSENSITIVE

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based| Department8, 2015 GATEWAY6.1viii ACRONYMS,4-97 January 1997206-98

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

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

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

  10. Molecular Characterization of Bacterial Respiration on Minerals

    SciTech Connect (OSTI)

    Blake, Robert C.

    2013-04-26

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

  11. Multi-level RF identification system

    DOE Patents [OSTI]

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

    2004-07-20

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

  12. Longitudinal beam dynamics with rf noise

    SciTech Connect (OSTI)

    Shih, H.J.; Ellison, J.A.; Cogburn, R.; Newberger, B.S.

    1993-06-01

    The Dome-Krinsky-Wang (DKW) diffusion-inaction theory for rf-noise-induced emittance dilution is reviewed and related to recent work on the approximation of stochastic processes by Markov processes. An accurate and efficient numerical procedure is developed to integrate the diffusion equation of the DKW theory. Tracking simulations are undertaken to check the validity of the theory in the parameter range of the Superconducting Super Collider (SSC) and to provide additional information. The study of effects of rf noise is applied to two problems of interest at the SSC: (1) determination of noise tolerance levels in the rf system, and (2) feasibility of beam extraction using crystal channeling.

  13. Nb-Pb superconducting RF gun

    SciTech Connect (OSTI)

    J. Sekutowicz; J. Iversen; G. Kreps; W.D. Moller; W. Singer; X. Singer; I. Ben-Zvi; A. Burrill; J. Smedley; T. Rao; M. Ferrario; P. Kneisel; J. Langner; P. Strzyzewski; R. Lefferts; A. Lipski; K. Szalowski; K. Ko; L. Xiao

    2006-04-14

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  14. Matching network for RF plasma source

    DOE Patents [OSTI]

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

    2007-11-20

    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.

  15. WHICH MASK OR RESPIRATOR SHOULD I USE? SURGICAL MASK

    E-Print Network [OSTI]

    Wood, Marcelo A.

    or carcinogens CARTRIDGE RESPIRATOR: Must be cleared by EH&S* Appropriate for use: · To protect against chemical infectious agents · Will be provided if necessary, after a risk assessment from EH&S *For N-95 or cartridge

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

    SciTech Connect (OSTI)

    Brachmann, Axel; Dowell, David; /SLAC

    2012-06-25

    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.

  17. The morphological and chemical characteristics of respirable mineral wool fibers 

    E-Print Network [OSTI]

    Butler, Donnie Ray

    1976-01-01

    12 17 18 18 21 23 27 38 46 REFERENCES APPENDIX A TABLE OF CONTENTS continued ~Pa e 48 PHYSICAL CHARACTERISTICS OF OBSERVED FIBERS APPENDIX B X-RAY COUNT DATA OF OBSERVED FIBERS APPENDIX C PUMP CALIBRATION APPENDIX D COATING... LIST OF FIGURES continued 16. Lengths of fibers present in the respirable sample 17. Widths of fibers present in the respirable sample 18. Ternary diagram showing the Magnesium:Silicon: Calcium ratio of the observed fibers 19. Ternary diagram...

  18. Fabrication of Niobium sheet for RF cavities 

    E-Print Network [OSTI]

    Balachandran, Shreyas

    2009-05-15

    This thesis investigated the microstructure and mechanical property of RRR( high purity) and RG (low purity) niobium (Nb) sheet material. RRR Nb is used in the fabrication RF cavities. Our method involves processing bulk ...

  19. Conquering Noise for Accurate RF and

    E-Print Network [OSTI]

    Anlage, Steven

    Conquering Noise for Accurate RF and Microwave Signal © Agilent Technologies, Inc. 2009 Microwave Signal Measurements Presented by: Ernie Jackson #12;The Noise Presentation · Review of Basics, Some Advanced & Newer Approaches · Noise in Signal Measurements-Summary · Basic Noise Reduction Approaches

  20. Monolithic RF frontends for ubiquitous wireless connectivity

    E-Print Network [OSTI]

    Goswami, Sushmit

    2014-01-01

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

  1. Si-based RF MEMS components.

    SciTech Connect (OSTI)

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

    2005-01-01

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

  2. Samsung: ENERGY STAR Referral (RF26VAB)

    Broader source: Energy.gov [DOE]

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

  3. Deeply scaled CMOS for RF power applications

    E-Print Network [OSTI]

    Scholvin, Jörg, 1976-

    2006-01-01

    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 ...

  4. Quantifying intra- and inter-fractional motion in breast radiotherapy

    SciTech Connect (OSTI)

    Jones, Scott; Fitzgerald, Rhys; Owen, Rebecca; Ramsay, Jonathan

    2015-03-15

    The magnitude of intra- and inter-fractional variation in the set up of breast cancer patients treated with tangential megavoltage photon beams was investigated using an electronic portal imaging device (EPID). Daily cine-EPID images were captured during delivery of the tangential fields for ten breast cancer patients treated in the supine position. Measurements collected from each image included the central lung distance (CLD), central flash distance (CFD), superior axial measurement (SAM) and the inferior axial measurement (IAM). The variation of motion within a fraction (intra-fraction) and the variation between fractions (inter-fraction) was analysed to quantify set up variation and motion due to respiration. Altogether 3775 EPID images were collected from 10 patients. The effect of respiratory motion during treatment was <0.1 cm standard deviation (SD) in the anterior–posterior (AP) direction. The inter-fraction movement caused by variations in daily set up was larger at 0.28 cm SD in the AP direction. Superior–inferior (SI) variation was more difficult to summarise and proved unreliable as the measurements were taken to an ambiguous point on the images. It was difficult to discern true SI movement from that implicated by AP movement. There is minimal intra-fractional chest wall motion due to respiration during treatment. Inter-fractional variation was larger, however, on average it remained within departmental tolerance (0.5 cm) for set up variations. This review of our current breast technique provides confidence in the feasibility of utilising advanced treatment techniques (field-in-field, intensity modulated radiotherapy or volumetric modulated arc therapy) following a review of the current imaging protocol.

  5. Micropower RF material proximity sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-01-01

    A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is of the sensor. Thus, it can be used in corrosive environments, as well as in a wide variety of applications. An antenna has a characteristic impedance which depends on the materials in proximity to the antenna. An RF oscillator, which includes the antenna and is based on a single transistor in a Colpitt's configuration, produces an oscillating signal. A detector is coupled to the oscillator which signals changes in the oscillating signal caused by changes in the materials in proximity to the antenna. The oscillator is turned on and off at a pulse repetition frequency with a low duty cycle to conserve power. The antenna consists of a straight monopole about one-quarter wavelength long at the nominal frequency of the oscillator. The antenna may be horizontally disposed on a container and very accurately detects the fill level within the container as the material inside the container reaches the level of the antenna.

  6. Fractional Heisenberg Equation

    E-Print Network [OSTI]

    Vasily E. Tarasov

    2008-04-03

    Fractional derivative can be defined as a fractional power of derivative. The commutator (i/h)[H, ], which is used in the Heisenberg equation, is a derivation on a set of observables. A derivation is a map that satisfies the Leibnitz rule. In this paper, we consider a fractional derivative on a set of quantum observables as a fractional power of the commutator (i/h)[H, ]. As a result, we obtain a fractional generalization of the Heisenberg equation. The fractional Heisenberg equation is exactly solved for the Hamiltonians of free particle and harmonic oscillator. The suggested Heisenberg equation generalize a notion of quantum Hamiltonian systems to describe quantum dissipative processes.

  7. Fractional Classical Mechanics

    E-Print Network [OSTI]

    Nick Laskin

    2013-02-03

    Fractional classical mechanics has been introduced and developed as a classical counterpart of the fractional quantum mechanics. Lagrange, Hamilton and Hamilton-Jacobi frameworks have been implemented for the fractional classical mechanics. The Lagrangian of fractional classical mechanics has been introduced, and equation of motion has been obtained. Fractional oscillator model has been launched and solved in 1D case. A new equation for the period of oscillations of fractional classical oscillator has been found. The interplay between the energy dependency of the period of classical oscillations and the non-equidistant distribution of the energy levels for fractional quantum oscillator has been discussed. We discuss as well, the relationships between new equations of fractional classical mechanics and the well-known fundamental equations of classical mechanics.

  8. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    SciTech Connect (OSTI)

    Johnson, Rolland

    2014-09-21

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

  9. RF-Photonic Frequency Stability Gear Box

    E-Print Network [OSTI]

    Matsko, Andrey B; Ilchenko, Vladimir S; Seidel, David; Maleki, Lute

    2011-01-01

    An optical technique based on stability transfer among modes of a monolithic optical microresonator is proposed for long therm frequency stabilization of a radiofrequency (RF) oscillator. We show that locking two resonator modes, characterized with dissimilar sensitivity in responding to an applied forcing function, to a master RF oscillator allows enhancing the long term stability of a slave RF oscillator locked to two resonator modes having nearly identical sensitivity. For instance, the stability of a 10 MHz master oscillator characterized with Allan deviation of 10^-7 at 10^4s can be increased and transferred to a slave oscillator with identical stability performance, so that the resultant Allan deviation of the slave oscillator becomes equal to 10-13 at 10^4s. The method does not require absolute frequency references to achieve such a performance.

  10. X-Band RF Gun Development

    SciTech Connect (OSTI)

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

    2012-06-22

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

  11. High RF Power Production for CLIC

    E-Print Network [OSTI]

    Syratchev, I; Adli, E; Taborelli, M

    2007-01-01

    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 excite preferentially the synchronous mode. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and delivered to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability and main linac RF power needs. Another requirement is to provide local RF power termination in case of accelerating structure failure (ON/OFF capability). Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design

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

    E-Print Network [OSTI]

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

    2002-01-01

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

  13. Fractional Electromagnetic Waves

    E-Print Network [OSTI]

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

    2011-08-31

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

  14. May/June 2011 MAQS & Respirators Bee-ing Involved Counting Frames of Bees

    E-Print Network [OSTI]

    Ishida, Yuko

    , neoprene, or nitrile), and protective eyewear. Wear a respirator with an organic-vapor removing cartridge), or a NIOSH approved respirator with an organic vapor (OV) cartridge or canister with any N, R, P or HE

  15. eZ430-RF2500 Development Tool User's Guide

    E-Print Network [OSTI]

    ............................................................................................................... 6 2 eZ430-RF2500 Battery Board....................................................... 10 5 9600 bps With No Flow Control

  16. RF Design of the LCLS Gun

    SciTech Connect (OSTI)

    Limborg-Deprey, C

    2010-12-13

    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.

  17. Redefinition and global estimation of basal ecosystem respiration rate

    E-Print Network [OSTI]

    Chen, Jiquan

    at the mean annual 1 College of Global Change and Earth System Science, Beijing Normal University, Beijing Michele all'Adige, Italy. 12 Alterra, Earth System ScienceClimate Change, Wageningen University, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally

  18. Hydrogen Metabolism and the Evolution of Biological Respiration

    E-Print Network [OSTI]

    Johnson, Clark M.

    Hydrogen Metabolism and the Evolution of Biological Respiration Two separate families of enzymes that oxidize hydrogen and also produce it arose through convergent evolution Eric S. Boyd, Gerrit J. Schut. SLP, which can combine with electron bifurcation (EB) in anaerobes such as hydrogen

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

    E-Print Network [OSTI]

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

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

    E-Print Network [OSTI]

    Govindjee "Gov"

    on red light that plants, algae and cyanobacteria emit when exposed to UV and visible light. This new Lambers and Miquel Ribas-Car- bo, respectively) deal with several aspects of `Plant Respiration.' Volume by the absorption of visible light and conversion of photon energy to energy stored as redox potential, the transmem

  1. RF MEMS DC CONTACT SWTCHES FOR RECONFIGURABLE Presented to the

    E-Print Network [OSTI]

    Kassegne, Samuel Kinde

    RF MEMS DC CONTACT SWTCHES FOR RECONFIGURABLE ANTENNAS _______________ A Thesis Presented STATE UNIVERSITY The Undersigned Faculty Committee Approves the Thesis of Lei Zhou: RF DC Contact MEMS rock and water, water, through persistence, eventually wins. #12;vi ABSTRACT OF THE THESIS RF MEMS DC

  2. Bent crystal extraction of the SSC beam with RF noise induced diffusion

    SciTech Connect (OSTI)

    Shih, H.J. ); Taratin, A.M. )

    1991-03-01

    Channeling of charged particles in bent crystals has been considered for use in parasitic extraction of the Superconducting Super Collider (SSC) beam. To make this feasible, a small fraction of the SSC proton beam must be brought onto a bent crystal. In this paper, the method of introducing filtered phase noise into the rf system to diffuse the tails of the beam was investigated using computer simulations. The channeling efficiency of an incident beam by a bent silicon crystal was then analyzed using a theory and simulations. In addition, the increase in channeling efficiency because of the possibility of multiple passage through the crystal was studied in the presence of the injected filtered rf noise. 14 refs., 17 figs.

  3. Foliar respiration acclimation to temperature and temperature variable Q10 alter ecosystem carbon balance

    E-Print Network [OSTI]

    Thomas, David D.

    of mass- and area-based foliar dark respiration, above ground net primary production (ANPP), and foliar respiration­ photosynthesis ratios. The Rdacclim algorithm adjusted dark respiration downwards at temperatures above 18 1C, and adjusted rates up at temperatures below 5 1C. The Q10var algorithm adjusted dark

  4. (Carbon isotope fractionation inplants)

    SciTech Connect (OSTI)

    O'Leary, M.H.

    1990-01-01

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

  5. Rugged Ceramic Window for RF Applications

    SciTech Connect (OSTI)

    Neubauer, Michael; Johnson, Rolland P.; Rimmer, Robert; Elliot, Tom; Stirbet, Mircea

    2009-05-04

    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.

  6. An Efficient RF Source for Jlab

    SciTech Connect (OSTI)

    Neubauer, M.; Dudas, A.; Rimmer, Robert A.; Wang, Haipeng

    2013-12-01

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

  7. ILC RF System R and D

    SciTech Connect (OSTI)

    Adolphsen, Chris; /SLAC

    2012-07-03

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

  8. The new RF sources for accelerators

    SciTech Connect (OSTI)

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

    2012-12-21

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

  9. RUGGED CERAMIC WINDOW FOR RF APPLICATIONS

    SciTech Connect (OSTI)

    MIKE NEUBAUER

    2012-11-01

    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.

  10. Cathode Ion Bombardment in RF Photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V.

    2008-09-01

    In this paper, we use the method of rapid oscillating field to solve the equation of ion motion in an RF gun. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper proposes a simple mitigation recipe that can reduce the rate of ion bombardment.

  11. RF Gun Photocathode Research at SLAC

    SciTech Connect (OSTI)

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

    2012-05-16

    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.

  12. The Murmansk Initiative - RF: Acceptance Testing

    SciTech Connect (OSTI)

    Czajkowski, C.; Wester, D. W.; Dyer, R. S.; Soerlie, A. A.; Moller, B.; Barnes, E.

    2002-02-26

    The Murmansk Initiative-RF (MI) was conceived to provide the Russian Federation (RF) with the capacity to manage low-level liquid radioactive waste (LLRW) and comply with the requirements of the London Convention that prohibit ocean dumping. The trilateral project among Norway, the RF, and the United States of America (U.S.) began in 1994 and was the first to utilize exclusively Russian subcontractors to upgrade and expand an existing LLRW treatment plant on the premises of RTP Atomflot in Murmansk, Russia. The project moved quickly through the design phase. Progress during the construction phase was somewhat slower because of difficulties with acquisition of hardware, inexperience with automated instrumentation and control equipment, and unexpected design changes in the cementation unit. The project advanced into the test-operation phase, which is currently underway, in June 2001. Initial runs with liquid waste have revealed that procedures for unloading spent ion-exchange sorbents could be improved and that sludges formed during removal of alkaline-earth metals should be compacted in order for the facility to operate at its full potential. Resolution of these issues is expected within the next few months.

  13. Reducing the Heat Load on the LCLS 120 Hz RF Gun with RF Pulse Shaping

    SciTech Connect (OSTI)

    Schmerge, J.

    2005-01-31

    The LCLS injector must operate at 120 Hz repetition frequency but to date the maximum operating frequency of an S-band rf gun has been 50 Hz. The high fields desired for the LCLS gun operation limit the repetition frequency due to thermal expansion causing rf detuning and field redistribution. One method of addressing the thermal loading problem is too reduce the power lost on the cavity walls by properly shaping the rf pulse incident on the gun. The idea is to reach the steady state field value in the gun faster than the time constant of the gun would allow when using a flat incident rf pulse. By increasing the incident power by about a factor of three and then decreasing the incident power when the field reaches the desired value in the gun, the field build up time can be decreased by more than a factor of three. Using this technique the heat load is also decreased by more than a factor of three. In addition the rf coupling coefficient can be increased from the typical critically coupled designs to an overcoupled design which also helps reduce the field build up time. Increasing the coupling coefficient from 1 to 2 reduces the heat load by another 25% and still limits the reflected power and coupling hole size to manageable levels.

  14. Evaluation of respirator fit training by quantitative fit testing 

    E-Print Network [OSTI]

    Chute, Daniel Otis

    1981-01-01

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

  15. A discrete fractional random transform

    E-Print Network [OSTI]

    Zhengjun Liu; Haifa Zhao; Shutian Liu

    2006-05-20

    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.

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

    E-Print Network [OSTI]

    Turemen, G; Unel, G; Alacakir, A

    2015-01-01

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

  17. Realization and modeling of rf superconducting quantum interference device metamaterials

    E-Print Network [OSTI]

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

    2013-10-28

    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.

  18. EM modeling of RF drive in DTL tank 4

    SciTech Connect (OSTI)

    Kurennoy, Sergey S.

    2012-06-19

    A 3-D MicroWave Studio model for the RF drive in the LANSCE DTL tank 4 has been built. Both eigensolver and time-domain modeling are used to evaluate maximal fields in the drive module and RF coupling. The LANSCE DTL tank 4 has recently been experiencing RF problems, which may or may not be related to its replaced RF coupler. This situation stimulated a request by Dan Rees to provide EM modeling of the RF drive in the DTL tank 4 (T4). Jim O'Hara provided a CAD model that was imported into the CST Microwave Studio (MWS) and after some modifications became a part of a simplified MWS model of the T4 RF drive. This technical note describes the model and presents simulation results.

  19. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Anlage, Steven

    2014-07-23

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

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

    SciTech Connect (OSTI)

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

    2012-05-14

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

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

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

    diamond (UNCD) as a dielectric. A specialized radio frequency (RF) micro-electromechanical system (MEMS) switch that promises enhanced capabilities for next-generation...

  2. DEVELOPMENT AND TESTING OF HIGH POWER RF VECTOR MODULATORS*

    SciTech Connect (OSTI)

    Kang, Yoon W [ORNL; Wilson, Joshua L [ORNL; Champion, Mark [FNAL; Hardek, Thomas W [ORNL; Kim, Sang-Ho [ORNL; McCarthy, Mike [ORNL; Vassioutchenko, Alexandre V [ORNL

    2007-01-01

    A fan-out RF power distribution system can allow many accelerating cavities to be powered by a single high-power klystron amplifier. High-power vector modulators can perform independent control of amplitudes and phases of RF voltages at the cavities without changing the klystron signal. A prototype highpower RF vector modulator employing a quadrature hybrid and two ferrite phase shifters in coaxial TEM transmission lines has been built and tested for 402.5 MHz. RF properties of the design and results of high power testing are presented.

  3. Locking Lasers to RF in an Ultra Fast FEL

    E-Print Network [OSTI]

    Wilcox, R.

    2011-01-01

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

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

    DOE Patents [OSTI]

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

    1998-01-01

    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.

  5. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 5, OCTOBER 2007 1185 RF MEMS Sequentially Reconfigurable Sierpinski

    E-Print Network [OSTI]

    Tentzeris, Manos

    JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 5, OCTOBER 2007 1185 RF MEMS Sequentially, RF microelectromechanical systems (RF MEMS), Sierpinski fractal antenna. I. INTRODUCTION THE RF microelectromechanical systems (RF MEMS) switches are quickly becoming a popular switching ele- ment among microwave

  6. CLIC RF High Power Production Testing Program

    E-Print Network [OSTI]

    Syratchev, I; Tantawi, S

    2008-01-01

    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 (~ 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.

  7. Sandia National Laboratories: RF & Photonics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcoming Release of thePrograms:Mode Stirred ChamberReuseQuantum SystemsRF

  8. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

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

    2012-01-01

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

  9. Recent advances in RF power generation

    SciTech Connect (OSTI)

    Tallerico, P.J.

    1990-01-01

    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.

  10. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    A Compact Cantilever-Based RF MEMS Switch andA High-Performance RF MEMS Metal-Contact Switch and Switch-B High-Q 3-/4-Bit RF MEMS Digitally Tunable Capacitors for

  11. Quasi-optical network analyzers and high-reliability RF MEMS switched capacitors

    E-Print Network [OSTI]

    Grichener, Alexander

    2011-01-01

    Chapter 3 High-Reliability RF MEMS Switched Capacitors 3.1Technology 1.2 RF MEMS Technology . . . . . . . . . . . . .Reliability High-Q Switched RF MEMS Capacitors” IEEE Int.

  12. Cooling at the quantum limit and RF refrigeration

    E-Print Network [OSTI]

    Fominov, Yakov

    Cooling at the quantum limit and RF refrigeration Jukka Pekola Low Temperature Laboratory, Helsinki (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single as a refrigerator Optimum cooling power is reached at V 2/e: Cooling power of a NIS junction: Temperature TN

  13. RF Power Potential of 45 nm CMOS Technology Usha Gogineni

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    RF Power Potential of 45 nm CMOS Technology Usha Gogineni 1 , Jesús A. del Alamo 1 devices in recent years has motivated their use in millimeter-wave power applications. Specific, VT Abstract - This paper presents the first measurements of the RF power performance of 45 nm CMOS

  14. DEVELOPMENT OF BROADBAND LOW-VOLTAGE RF MEM SWITCHES

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    DEVELOPMENT OF BROADBAND LOW-VOLTAGE RF MEM SWITCHES S.C. Shen, D. T. Becher, D. C. Caruth, and M)333-4054 Fax: (217) 244-6375 Abstract We present novel RF switches using micro-electro- mechanical (MEM) technology. These MEM switches are built on GaAs substrates using GaAs MESFET MMIC- compatible processes

  15. RF cavity using liquid dielectric for tuning and cooling

    DOE Patents [OSTI]

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

    2012-04-17

    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.

  16. Booster Synchrotron RF System Upgrade for SPEAR3

    SciTech Connect (OSTI)

    Park, Sanghyun; Corbett, Jeff; /SLAC

    2012-07-06

    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.

  17. Dial It In: Rotating RF Sensors to Enhance Radio Tomography

    E-Print Network [OSTI]

    Patwari, Neal

    --A radio tomographic imaging (RTI) system uses the received signal strength (RSS) measured by RF sensors of the antenna of each RF sensor can dramatically affect imaging and localization performance of an RTI system in a deployed RTI system requires the deployer to iteratively "guess-and-retest", i.e., pick a sensor to move

  18. Beyond ITER: RF Heating and Current Drive Issues for DEMO

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    Current devices Need flexible RF systems for heating, CD, start-up, instability suppression, and profileBeyond ITER: RF Heating and Current Drive Issues for DEMO C. K. Phillips, J. C. Hosea, G. Taylor under development ­ May need Lower Hybrid for r/a > 0.6 (not currently on ITER) ­ Need feedback control

  19. Model Reduction for RF MEMS Simulation David S. Bindel1

    E-Print Network [OSTI]

    California at Davis, University of

    Model Reduction for RF MEMS Simulation David S. Bindel1 , Zhaojun Bai2 , and James W. Demmel3 1@eecs.berkeley.edu Abstract. Radio-frequency (RF) MEMS resonators, integrated into CMOS chips, are of great interest-preserving model-reduction techniques and apply them to the frequency-domain analysis of two proposed MEMS

  20. RF-MEMS capacitive switches with high reliability

    DOE Patents [OSTI]

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

    2013-09-03

    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.

  1. Shielded RF Lattice for the Muon Front End Chris Rogers,

    E-Print Network [OSTI]

    McDonald, Kirk

    Shielded RF Lattice for the Muon Front End Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12; Shielded RF Lattice I wanted to remind folks a lot of slides apologies I've tried to break it up a bit #12; Part 1 Shielded Lattice Baseline

  2. Tunnel MOS Heterostructure Field Effect Transistor for RF Switching Applications 

    E-Print Network [OSTI]

    Rezanezhad Gatabi, Iman

    2013-06-06

    GaN RF switches are widely used in today’s communication systems. With digital communications getting more and more popular nowadays, the need for improving the performance of involved RF switches is inevitable. Designing low ON-state resistance Ga...

  3. Clean fractionation of biomass

    SciTech Connect (OSTI)

    Not Available

    1995-01-01

    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.

  4. Upgrade of the cryogenic CERN RF test facility

    SciTech Connect (OSTI)

    Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B.; Koettig, T.

    2014-01-29

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

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

    SciTech Connect (OSTI)

    Yonehara, K.; /Fermilab

    2010-09-01

    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.

  6. Cold Test Measurements on the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Gierman, S.M.

    2010-12-03

    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.

  7. Progress on a cryogenically cooled RF gun polarized electron source

    SciTech Connect (OSTI)

    Fliller, R.P., III; Edwards, H.; /Fermilab

    2006-08-01

    RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.

  8. LHC RF System Time-Domain Simulation

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.

    2010-09-14

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

  9. RF Power Generation in LINAC4

    E-Print Network [OSTI]

    Brunner, O; Schwerg, J N

    2010-01-01

    Linac4 is a lin­ear ac­cel­er­a­tor for neg­a­tive Hy­dro­gen ions (H-) which will re­place the old Linac2 as lin­ear in­jec­tor for the CERN ac­cel­er­a­tors. Its high­er en­er­gy of 160 MeV will give in­creased beam in­ten­si­ty in the down­stream ma­chines. Linac4 is about 100 m long, nor­mal-con­duct­ing, and will be housed in a tun­nel about 12 m below ground. The Linac4 tun­nel will be con­nect­ed to the ex­ist­ing chain of ac­cel­er­a­tors and can be ex­tend­ed to the new in­jec­tion chain. The high RF power for the Linac4 ac­cel­er­at­ing struc­tures will be gen­er­at­ed by thir­teen 1.3 MW klystrons, pre­vi­ous­ly used for the CERN LEP ac­cel­er­a­tor, and six new 2.8 MW klystrons of all op­er­at­ing at a fre­quen­cy of 352.2 MHz. The in­te­gra­tion of the RF power sys­tem in the build­ing is pre­sent­ed. The tech­ni­cal spec­i­fi­ca­tions and the per­for­mance of the var­i­ous high-pow­er el­e­ments are dis­cussed, ...

  10. Incorporating temperature-sensitive Q10 and foliar respiration acclimation algorithms modifies modeled ecosystem

    E-Print Network [OSTI]

    Minnesota, University of

    Incorporating temperature-sensitive Q10 and foliar respiration acclimation algorithms modifies model PnET-CN. We examined the new algorithms' effects on modeled net primary production (NPP), total] and warming was 9% greater when RA algorithms were used, relative to responses using fixed respiration

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

    E-Print Network [OSTI]

    Malhi, Yadvinder

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

  12. 3MTM Air-MateTM Belt Mounted High Efficiency Powered Air Purifying Respirator (PAPR)

    E-Print Network [OSTI]

    Acton, Scott

    3MTM Air-MateTM Belt Mounted High Efficiency Powered Air Purifying Respirator (PAPR) Welcome and thank you for choosing the 3MTM Air-MateTM Belt Mounted High Efficiency Powered Air Purifying Respirator text #12;Double click picture to start video Click button to view video text #12;3MTM Air-MateTM Belt

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

    E-Print Network [OSTI]

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

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

    E-Print Network [OSTI]

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

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

    E-Print Network [OSTI]

    Minnesota, University of

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

  16. Fractional channel multichannel analyzer

    DOE Patents [OSTI]

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

    1994-08-23

    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.

  17. Respiration-Induced B0 Fluctuations and Their Spatial Distribution in the Human Brain at 7 Tesla

    E-Print Network [OSTI]

    Glover, Gary H.

    Respiration-Induced B0 Fluctuations and Their Spatial Distribution in the Human Brain at 7 Tesla that suscep- tibility variations generated during respiration are expected to be responsible f

  18. Listing Unique Fractional Factorial Designs 

    E-Print Network [OSTI]

    Shrivastava, Abhishek Kumar

    2011-02-22

    Fractional factorial designs are a popular choice in designing experiments for studying the effects of multiple factors simultaneously. The first step in planning an experiment is the selection of an appropriate fractional ...

  19. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect (OSTI)

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

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

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

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based| Department8, 2015 GATEWAY6.1viii ACRONYMS,4-97 January 1997206-9810-94

  1. Clean fractionation of biomass

    SciTech Connect (OSTI)

    1995-09-01

    The US 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. A consortium of five DOE national laboratories has been formed with the objectives of providing industry with a broad range of expertise and helping to lower the risk of new process development through federal cost sharing. The AF program is conducting ongoing research on a clean fractionation process, designed to convert biomass into materials that can be used for chemical processes and products. The focus of the clean fractionation research is to demonstrate to industry that one technology can successfully separate all types of feedstocks into predictable types of chemical intermediates.

  2. Upgrading EMMA to Use Low-frequency RF Cavities

    SciTech Connect (OSTI)

    Ohmori, C.; Berg, J.

    2011-04-30

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

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

    SciTech Connect (OSTI)

    Qian, Di; Bottomley, Paul A.; El-Sharkawy, AbdEl-Monem M.; Edelstein, William A.

    2013-12-15

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

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

    SciTech Connect (OSTI)

    Kopalidis, Peter M.; Wan Zhimin

    2012-11-06

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

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

    DOE Patents [OSTI]

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

    2008-04-22

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

  6. RF-MEMS load sensors with enhanced Q-factor and sensitivity in a suspended architecture

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    RF-MEMS load sensors with enhanced Q-factor and sensitivity in a suspended architecture Rohat Melik-implant RF-MEMS a b s t r a c t In this paper, we present and demonstrate RF-MEMS load sensors designed the strain change in real-time. For this purpose, we present RF- MEMS resonator sensors that shift

  7. Microwave Laminate PCB Compatible RF MEMS Technology for Wireless Communication Systems

    E-Print Network [OSTI]

    De Flaviis, Franco

    Microwave Laminate PCB Compatible RF MEMS Technology for Wireless Communication Systems * Bedri A microwave laminate printed circuit board (PCB) compatible RF MEMS technology for wireless communication systems. This technology is novel in that RF MEMS components, particularly RF MEM switches, can

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

    E-Print Network [OSTI]

    Gubicza, Jenõ

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

  9. Electrical degradation mechanisms of RF power GaAs PHEMTs

    E-Print Network [OSTI]

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

    2007-01-01

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

  10. Possible high power limitations from RF pulsed heating

    SciTech Connect (OSTI)

    Pritzkau, D.P.; Bowden, G.B.; Menegat, A.; Siemann, R.H. [Stanford Linear Accelerator Center, Stanford University, California 94309 (United States)

    1999-05-01

    One of the possible limitations to achieving high power in RF structures is damage to metal surfaces due to RF pulsed heating. Such damage may lead to degradation of RF performance. An experiment to study RF pulsed heating on copper has been developed at SLAC. The experiment consists of operating two pillbox cavities in the TE{sub 011} mode using a 50 MW X-Band klystron. The estimated temperature rise of the surface of copper is 350&hthinsp;{degree}C for a power input of 20 MW to each cavity with a pulse length of 1.5 {mu}s. Preliminary results from an experiment performed earlier are presented. A revised design for continued experiments is also presented along with relevant theory and calculations. {copyright} {ital 1999 American Institute of Physics.}

  11. Efficiency enhancement techniques for RF and millimeter wave power amplifiers

    E-Print Network [OSTI]

    Ogunnika, Olumuyiwa Temitope, 1978-

    2012-01-01

    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 ...

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

    E-Print Network [OSTI]

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-01-01

    to Mod, Feb. 7, 2002] SRRF Klystron Beam Current (A) [AfterTime (hrs) Figure 2: SRRF Klystron Efficiency Comparison forKLYSTRON “EFFICIENCY LOOP” FOR THE ALS STORAGE RING RF

  13. Superfluid helium cryogenic systems for superconducting RF cavities...

    Office of Scientific and Technical Information (OSTI)

    (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium,...

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

    SciTech Connect (OSTI)

    Yonehara, Katsuya; /Fermilab

    2011-12-02

    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.

  15. RADIATION SOLID STATE PHYSICS R.F. Konopleva

    E-Print Network [OSTI]

    Titov, Anatoly

    233 RADIATION SOLID STATE PHYSICS R.F. Konopleva The development of the nuclear and nuclear fusion, and the thermonuclear devices. In this connection the "Laboratory of the non-equilibrium electronic processes

  16. BN/Graphene/BN Transistors for RF Applications

    E-Print Network [OSTI]

    Taychatanapat, Thiti

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

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

    E-Print Network [OSTI]

    Atre, Mahesh Purushottam

    1992-01-01

    FREQUENCY AND AMPLITUDE CONTROL FOR AN EXPERIMENTAL LINAC RF DRIVE A Thesis by MAHESH PURUSHOTTAM ATRE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Electrical Engineering FREQUENCY AND AMPLITUDE CONTROL FOR AN EXPERIMENTAL LINAC RF DRIVE A Thesis by MAHESH PURUSHOTTAM ATRE Approved as to style and content by: S. P. Bhattachary (Chair of Committee) arng Huang...

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

    E-Print Network [OSTI]

    Wu, Yu

    1993-01-01

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

  19. DOE planning workshop on rf theory and computations

    SciTech Connect (OSTI)

    Not Available

    1984-01-01

    The purpose of the two-day workshop-meeting was to review the status of rf heating in magnetic fusion plasmas and to determine the outstanding problems in this area. The term rf heating was understood to encompass not only bulk plasma heating by externally applied electromagnetic power but also current generation in toroidal plasmas and generation of thermal barriers in tandem mirror plasmas.

  20. Handbook for Gas Filled RF Cavity Aficionados'

    SciTech Connect (OSTI)

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

    2009-05-01

    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.

  1. High power RF systems for the BNL ERL project

    SciTech Connect (OSTI)

    Zaltsman, A.; Lambiase, R.

    2011-03-28

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

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

    E-Print Network [OSTI]

    Burns, Nancy Rosalind

    2012-11-29

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

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

    E-Print Network [OSTI]

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

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

    SciTech Connect (OSTI)

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

    2011-09-26

    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.

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

    E-Print Network [OSTI]

    Thomas, David D.

    Elevated CO2 stimulates grassland soil respiration by increasing carbon inputs rather than by enhancing soil moisture E . C A R O L A D A I R * § , P E T E R B . R E I C H , J A R E D J . T R O It is not clear whether the consistent positive effect of elevated CO2 on soil respiration (soil carbon flux, SCF

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

    E-Print Network [OSTI]

    Gaudet, Glenn Lawrence

    1980-01-01

    the exhalation breath does not pass through the sorbent bed when exitino the respirator. On the other hand, valveless respirators such as the 3M iI8711 are partially cleansed by each exhalation breath. The preliminary studies indicated that the amount... surgeon or other operating room personnel, The Minnesota Mining and Manufacturing Company (3M) has marketed a disposable respirator called the 3M Spray Paint Respirator =8711. The respirator has the external configuration of a surgical mask. Since...

  7. High Power RF Test Facility at the SNS

    SciTech Connect (OSTI)

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

    2005-05-16

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

  8. RF Power Upgrade for CEBAF at Jefferson Laboratory

    SciTech Connect (OSTI)

    Andrew Kimber,Richard Nelson

    2011-03-01

    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.

  9. A 12 GHz RF Power Source for the CLIC Study

    SciTech Connect (OSTI)

    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

    2012-07-03

    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.

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

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin; Thomson, Allison M.

    2010-03-25

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

  11. Klystron 'efficiency loop' for the ALS storage ring RF system

    SciTech Connect (OSTI)

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-05-20

    The recent energy crisis in California has led us to investigate the high power RF systems at the Advanced Light Source (ALS) in order to decrease the energy consumption and power costs. We found the Storage Ring Klystron Power Amplifier system operating as designed but with significant power waste. A simple proportional-integrator (PI) analog loop, which controls the klystron collector beam current, as a function of the output RF power, has been designed and installed. The design considerations, besides efficiency improvement, were to interface to the existing system without major expense. They were to also avoid the klystron cathode power supply filter's resonance in the loop's dynamics, and prevent a conflict with the existing Cavity RF Amplitude Loop dynamics. This efficiency loop will allow us to save up to 700 MW-hours of electrical energy per year and increase the lifetime of the klystron.

  12. Adaptive RF Transient Reduction for HIGH Intensity Beams with Gaps

    E-Print Network [OSTI]

    Tückmantel, Joachim

    2006-01-01

    When a high-intensity beam with bunch-trains and gaps passes a cavity with a high-gain vector feedback enforcing a constant voltage, large transients appear, stressing the RF high power hardware and increasing the trip rate. By modulating the cavity voltage with a varying periodic waveform (set-function), the RF power can be made constant while still preserving the high feedback gain. The average cavity voltage is conserved but bunches have to settle at slightly shifted positions. A method is derived to obtain this set-function in practice while making no assumptions or measurements of the beam or RF parameters. Adiabatic iterations are made including the whole machine as an analog computing device, using all parameters as they are. A computer simulation shows the success of the method.

  13. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect (OSTI)

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

    1995-09-01

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

  14. Coating power RF components with TiN

    SciTech Connect (OSTI)

    Kuchnir, M.; Hahn, E.

    1995-03-01

    A facility for coating RF power components with thin films of Ti and/or TiN has been in operation for some time at Fermilab supporting the Accelerator Division RF development work and the TESLA program. It has been experimentally verified that such coatings improve the performance of these components as far as withstanding higher electric fields. This is attributed to a reduction in the secondary electron emission coefficient of the surfaces when coated with a thin film containing titanium. The purpose of this Technical Memorandum is to describe the facility and the procedure used.

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

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2010-01-01

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

  16. High linearity 1.5-2.5 GHz RF-MEMS and varactor diodes based tunable filters for wireless applications

    E-Print Network [OSTI]

    El-Tanani, Mohammed Ahmed

    2009-01-01

    5.2.3 RF-MEMS Tunable Capacitive Network . . . . . . . .5.3Wide-Bandwidth Miniaturized RF-MEMS Tun- ableApplications104 Appendix B RF MEMS Cantilever Fabrication

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

    SciTech Connect (OSTI)

    Gu, Lianhong; Van Gorsel, Eva; Leuning, Ray; Delpierre, Nicolas; Black, Andy; Chen, Baozhang; Munger, J. William; Wofsy, Steve; Aubinet, M.

    2009-11-01

    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

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

    SciTech Connect (OSTI)

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

    2013-12-01

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

  19. Microfluidic Devices for Blood Fractionation

    E-Print Network [OSTI]

    Hou, Han Wei

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

  20. Comparing the performance of plasma impedance probes and Langmuir probes for RF plasma diagnostics

    E-Print Network [OSTI]

    Walker, Mitchell

    conducted in a 14-ft diameter, 22-ft long diffusion-pumped vacuum chamber. Plasma was produced waves via RF heating. Results Conclusions For the discharge plasma condition, there was a significant hybrid frequency. RF Ca

  1. 1 Filter_Supplemental-Info_090913.doc Supplemental Information Regarding RF/Microwave Filter Design

    E-Print Network [OSTI]

    Weller/USF 1 Filter_Supplemental-Info_090913.doc Supplemental Information Regarding RF/Microwave Filter Design The video module on RF/microwave filter design, Filter Demonstration in Microwave Office

  2. Investigation of RF-enhanced plasma potentials on Alcator C-Mod

    E-Print Network [OSTI]

    Cziegler, I.

    Radio frequency (RF) sheath rectification is a leading mechanism suspected of causing anomalously high erosion of plasma facing materials in RF-heated plasmas on Alcator C-Mod. An extensive experimental survey of the plasma ...

  3. Inkjet-Printed Ferromagnetic Nanoparticles for Miniaturization of Flexible Printed RF Inductors

    E-Print Network [OSTI]

    Tentzeris, Manos

    the inductor for flexible printed electronics. This flexible, miniaturized inductor can be coupledInkjet-Printed Ferromagnetic Nanoparticles for Miniaturization of Flexible Printed RF Inductors to apply ferromagnetic nanomaterial is investigated to produce a truly flexible, printed RF inductor

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

    E-Print Network [OSTI]

    Sekar, Vikram

    2012-10-19

    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...

  5. Timing and RF Synchrotronization for Filling PEP/SPEAR with the SLC Damping Rings

    E-Print Network [OSTI]

    Ronan, M.T.

    2011-01-01

    respect to the beam and the Klystron 2.856 GHz RF over theto 2.856 GHz by the Klystron subboosters. A fiducialop- erating at lhe IlDac Klystron RF frequency (2.856 GHz)

  6. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    applications,” in Microelectromechanical Systems Conference,force microscopy,” Microelectromechanical Systems, JournalRF applications,” Microelectromechanical Systems, Journal

  7. RF power potential of 45 nm CMOS technology

    E-Print Network [OSTI]

    Putnam, Christopher

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

  8. Development of RF CMOS receiver front-ends for ultrawideband 

    E-Print Network [OSTI]

    Guan, Xin

    2009-05-15

    .5dB and a noise figure of 3.3-4.5dB from 3-9.5GHz, while only consuming 9mW power. Based on the distributed amplifier and resistive shunt-feedback amplifier designs, two UWB RF front-ends are developed. One is a distributed LNA-Mixer. Unlike...

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

    E-Print Network [OSTI]

    Hanson, George

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

  10. Sifting Through the Airwaves: Efficient and Scalable Multiband RF Harvesting

    E-Print Network [OSTI]

    Washington at Seattle, University of

    option. Compared to solar power, ambient RF has the advantage of being available at night starved of its energy source the device must cease to operate, limiting the application space mostly wideband harvesting can capture energy across a large swath of spectrum, it typically results in very low

  11. RF sputtered piezoelectric zinc oxide thin film for transducer applications

    E-Print Network [OSTI]

    Tang, William C

    parameters that could influence the quality of the resulting films include RF power, the ratio of argon depen- dency of the c-axis zinc oxide growth in radio-frequency sputtering system. Different deposition on the piezoelectric and crystalline qualities of the ZnO thin films. Experimental results showed that the multilayer

  12. EE 402 Microwave and RF Circuits Aqeel Ahmad Qureshi

    E-Print Network [OSTI]

    Saskatchewan, University of

    EE 402 Microwave and RF Circuits Aqeel Ahmad Qureshi aqeel.ahmad@usask.ca Objective: There is currently an explosion in wireless communications at microwave and millimeter-wave frequencies, for both-effective and highly integrated devices and circuits are required. An understanding of modern microwave theory

  13. LWA Equipment RF Emissions: Spectrum Analyzers and Ylva Pihlstrm, UNM

    E-Print Network [OSTI]

    Ellingson, Steven W.

    1 LWA Equipment RF Emissions: Spectrum Analyzers and Laptops Ylva Pihlström, UNM 8/27/06 Summary I be used at the LWDA site during standard VLA operations. Two brands of spectrum analyzers and laptop are therefore considered typical of spectrum analyzers and laptops. The results of the measurements suggest

  14. Klystron based high power rf system for proton accelerator

    SciTech Connect (OSTI)

    Pande, Manjiri; Shrotriya, Sandip; Sharma, Sonal; Patel, Niranjan; Handu, Verander, E-mail: manjiri@barc.gov.in, E-mail: manjiri08@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai (India)

    2011-07-01

    As a part of ADS program a proton accelerator (20 MeV, 30 mA) and its high power RF systems (HPRF) are being developed in BARC. This paper explains design details of this klystron based HPRF system. (author)

  15. Supply Chain Planning Analyst 4 Optical Components /RF Products

    E-Print Network [OSTI]

    Heller, Barbara

    Supply Chain Planning Analyst 4 Optical Components /RF Products Job Number: 82686511 Company Name to apply internal investment to improve their position in meeting current and future NGES sourcing needs, executing the plans put forth by the domain team. Minimum US citizen with ability to obtain DoD Secret

  16. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect (OSTI)

    Regan, A.H.; Roybal, W.T.; Ortega, R.; Palomares, M.; Rees, D.E.; Tischler, D.

    1996-06-01

    Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors have developed an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants. The authors have conducted a number of benchtop experiments involving RF/microwave energy deposition and vapor extraction on controlled contaminated soil samples with successful removal of the contaminants. This paper will describe the experimental hardware utilized, the experiments performed, the chemical analysis performed pre- and post-energy application, and results. In the experiments, two different halogenated liquids were used to contaminate the soil: carbon tetrachloride and 1,1,1-trichloroethane.

  17. Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low-Loss Spacer

    E-Print Network [OSTI]

    Technische Universiteit Delft

    Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low-Loss Spacer Substrate Alexander Polyakov #12;#12;Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low ICs...............................................13 1.4. Wafer-level packaging for RF applications

  18. Evidence that global processing does not limit thresholds for RF shape discrimination

    E-Print Network [OSTI]

    Mullen, Kathy T.

    Evidence that global processing does not limit thresholds for RF shape discrimination McGill Vision whether shape discrimination thresholds for radial frequency (RF) patterns are limited at this global.75­6 cpd). First, we show using sections of an RF4 that shape discrimination thresholds are invariant

  19. Performance Analysis of Simultaneous Wireless Information and Power Transfer with Ambient RF

    E-Print Network [OSTI]

    Privault, Nicolas

    isotropic wireless power, and reception of the power by converting the harvested RF waves into electricity. INTRODUCTION RF energy harvesting techniques have evolved as a promis- ing and cost-effective solutionPerformance Analysis of Simultaneous Wireless Information and Power Transfer with Ambient RF Energy

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

    E-Print Network [OSTI]

    Tentzeris, Manos

    Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control Ryo (WSN) that are solely powered by ambient RF power. Different from all other energy harvesting WSN systems, RF powered systems present a new challenge for the energy management. A WSN node repeatedly

  1. RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna Application

    E-Print Network [OSTI]

    De Flaviis, Franco

    RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna, University of California Irvine, Irvine, CA, 92697 Abstract: The air-bridged RF-MEMS switches in single pole) and coplanar waveguide (CPW) structures. RF-MEMS series switches are monolithic fabricated in both transmission

  2. Modeling and Optimization of RF-MEMS Reconfigurable Tuners with Computationally Efficient Time-Domain Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling and Optimization of RF-MEMS Reconfigurable Tuners with Computationally Efficient Time of Technology, Atlanta, GA 30332 2 Raytheon Company, Tucson AZ, 85734 Abstract -- Modern RF-MEMS device design methods in which the FDTD technique can be used to model a reconfigurable RF-MEMS tuner. A new method

  3. Low Cost RF MEMS Switches Fabricated on Microwave Laminate Printed Circuit Boards

    E-Print Network [OSTI]

    De Flaviis, Franco

    1 Low Cost RF MEMS Switches Fabricated on Microwave Laminate Printed Circuit Boards Hung-Pin Chang process for directly constructing RF MEMS capacitive switches has been developed on microwave laminate among components. Index Terms--RF MEMS switches, compressive molding planarization, high density

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

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z.; Mohai, I.; Szepvolgyi, J.

    2004-12-01

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

  5. The RF power system for the SNS linac

    SciTech Connect (OSTI)

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

    1998-12-31

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

  6. Microbial community production, respiration, and structure of the microbial food web of an ecosystem in the northeastern Atlantic Ocean

    E-Print Network [OSTI]

    Microbial community production, respiration, and structure of the microbial food web; accepted 1 June 2005; published 26 July 2005. [1] Gross community production (GCP), dark community production, respiration, and structure of the microbial food web of an ecosystem in the northeastern Atlantic

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

    SciTech Connect (OSTI)

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

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of the emittance compensation solenoid are discussed in Section 1.1.7. The novel feature of the LCLS solenoid is the embedded quadrupole correctors. The thermo-mechanical engineering of the LCLS gun is discussed in Section 1.1.8, and the cold and hot RF tests are described in Section 1.1.9. The results of this work are summarized and concluding remarks are given in Section 1.1.10.

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

    E-Print Network [OSTI]

    Lindgren, Kourtnee Marr

    2011-08-08

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

  9. Symmetry fractionalization and twist defects

    E-Print Network [OSTI]

    Nicolas Tarantino; Netanel Lindner; Lukasz Fidkowski

    2015-06-22

    Topological order in two dimensions can be described in terms of deconfined quasiparticle excitations - anyons - and their braiding statistics. However, it has recently been realized that this data does not completely describe the situation in the presence of an unbroken global symmetry. In this case, there can be multiple distinct quantum phases with the same anyons and statistics, but with different patterns of symmetry fractionalization - termed symmetry enriched topological (SET) order. When the global symmetry group $G$, which we take to be discrete, does not change topological superselection sectors - i.e. does not change one type of anyon into a different type of anyon - one can imagine a local version of the action of $G$ around each anyon. This leads to projective representations and a group cohomology description of symmetry fractionalization, with $H^2(G,{\\cal A})$ being the relevant group. In this paper, we treat the general case of a symmetry group $G$ possibly permuting anyon types. We show that despite the lack of a local action of $G$, one can still make sense of a so-called twisted group cohomology description of symmetry fractionalization, and show how this data is encoded in the associativity of fusion rules of the extrinsic `twist' defects of the symmetry. Furthermore, building on work of Hermele, we construct a wide class of exactly solved models which exhibit this twisted symmetry fractionalization, and connect them to our formal framework.

  10. The Bootstrap Fraction in TFTR

    SciTech Connect (OSTI)

    Hoang, G. T.

    1997-04-15

    The TRANSP plasma analysis code is used to calculate the bootstrap current generated during neutral-beam injection and ion cyclotron resonance frequency heating for a wide variety of TFTR discharges. An empirical scaling relation is given for the bootstrap current fraction using the ratio of the peakedness of the thermal pressure and the total current density.

  11. Gauge Invariance and Fractional Statistics

    E-Print Network [OSTI]

    A. R. P. Lima; R. R. Landim

    2006-10-04

    We present a new $(2+1)$-dimensional field theory showing exotic statistics and fractional spin. This theory is achieved through a redefinition of the gauge field $A_{\\mu}$. New properties are found. Another way to implement the field redefinition is used with the same results obtained.

  12. 332 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 51, NO. 1, JANUARY 2003 Monolithic Integration of RF MEMS Switches

    E-Print Network [OSTI]

    Cetiner, Bedri A.

    Integration of RF MEMS Switches With a Diversity Antenna on PCB Substrate B. A. Cetiner, Member, IEEE, J. Y integration of RF mi- croelectromechanical system (MEMS) switches with three-dimen- sional antenna elements with RF MEMS switches is designed and demonstrated. Index Terms--RF microelectromechanical system (MEMS

  13. Assessment of Alternative RF Linac Structures for APT

    SciTech Connect (OSTI)

    1997-03-26

    The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties.

  14. STATUS OF THE SPALLATION NEUTRON SOURCE SUPERCONDUCTING RF FACILITIES

    SciTech Connect (OSTI)

    Stout, Daniel S [ORNL] [ORNL; Assadi, Saeed [ORNL] [ORNL; Campisi, Isidoro E [ORNL] [ORNL; Casagrande, Fabio [ORNL] [ORNL; Crofford, Mark T [ORNL] [ORNL; DeVan, Bill [ORNL] [ORNL; Hardek, Thomas W [ORNL] [ORNL; Henderson, Stuart D [ORNL] [ORNL; Howell, Matthew P [ORNL] [ORNL; Kang, Yoon W [ORNL] [ORNL; Geng, Xiaosong [ORNL] [ORNL; Stone Jr, William C [ORNL] [ORNL; Strong, William Herb [ORNL] [ORNL; Williams, Derrick C [ORNL] [ORNL; Wright, Paul Alan [ORNL] [ORNL

    2007-01-01

    The Spallation Neutron Source (SNS) project was completed with only limited superconducting RF (SRF) facilities installed as part of the project. A concerted effort has been initiated to install the infrastructure and equipment necessary to maintain and repair the superconducting Linac, and to support power upgrade research and development (R&D). Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is underway. A horizontal cryostat, which can house a helium vessel/cavity and fundamental power coupler for full power, pulsed testing, is being procured. Equipment for cryomodule assembly and disassembly is being procured. This effort, while derived from the experience of the SRF community, will provide a unique high power test capability as well as long term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF facilities.

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

    SciTech Connect (OSTI)

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Vaccarezza, C.

    2009-05-01

    Velocity (or rf) compression has been suggested as a technique for bunch compression complementary to the more established technique involving magnetic chicanes and represents an important research item being investigated at the SPARC test facility. One of the aspects of this technique still not sufficiently understood is its possible impact on the microbunching instability. The purpose of this report is to present the analytical framework for investigating this instability in rf compressors. We use methods similar to those successfully applied to magnetic compressors and derive some integral equations yielding the gain for the instability in linear approximation. The focus here is on the derivation of the relevant equations. Although examples of solutions to these equations are provided we defer a more comprehensive discussion of their implication to a future report. The present study is part of a larger effort for a more comprehensive investigation that eventually will include macroparticle simulations and experiments.

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

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  17. Short-Period RF Undulator for a SASE Nanometer source

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2001-12-21

    Analysis is described towards development of a RF undulator with a period < 1 cm, an undulator parameter K of the order of unity, and a gap greater than 2.25 mm. The application for the undulator is for a SASE source to produce 1 nm wavelength radiation using a low energy electron beam in the range 1-2 GeV. Particle orbit calculations in a conventional standing-wave resonator configuration show that the presence of a co-propagating component of RF field can cause deleterious motion for the undulating electrons that can seriously degrade their radiation spectrum. To obviate this problem, resonator designs were devised in which only the counter-propagating field components interact with the particles. Two resonator configurations with the same undulator parameter K = 0.4 have been devised and are described in this report.

  18. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    Shu, G; Pei, S; Xiao, O

    2015-01-01

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

  19. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

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

    2015-05-28

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

  20. Characterization on RF magnetron sputtered niobium pentoxide thin films

    SciTech Connect (OSTI)

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

    2014-10-15

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

  1. Multipacting optimization of a 750 MHz rf dipole

    SciTech Connect (OSTI)

    Delayen, Jean R.; Castillo, Alejandro

    2014-12-01

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

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

    E-Print Network [OSTI]

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

  3. EFFICIENT SPECTRAL-GALERKIN METHODS FOR FRACTIONAL ...

    E-Print Network [OSTI]

    2015-11-17

    EFFICIENT SPECTRAL-GALERKIN METHODS FOR FRACTIONAL PARTIAL. DIFFERENTIAL EQUATIONS WITH VARIABLE COEFFICIENTS. ZHIPING MAO†

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

    E-Print Network [OSTI]

    Whisenant, Justin

    2011-05-05

    and combined effects of nitrogen and phosphorous additions on soil carbon cycling. We performed laboratory incubations on soil samples from two loblolly pine forests in Florida and measured the CO2 respired by soil microbes using an infrared gas analyzer. Our...

  5. Abstract This study compares approximately weekly soil respiration across two forestpasture

    E-Print Network [OSTI]

    Beltrami, Hugo

    carbon budget. Soils are the largest source of non-anthropogenic CO2 and hold approximately twice respiration it is impor- tant to quantify changes in soil CO2 emissions associated with shifts in vegetation with similar soil, topography and climate to document how conversion of pasture to forest alters net soil CO2

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

    E-Print Network [OSTI]

    Chen, Jiquan

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

  7. Carbon limitation of soil respiration under winter snowpacks: potential feedbacks between growing season

    E-Print Network [OSTI]

    Carbon limitation of soil respiration under winter snowpacks: potential feedbacks between growing season and winter carbon fluxes PA U L D . B R O O K S *, D I A N E M C K N I G H T w and K E L LY E L D- latitude and high-elevation ecosystems may increase soil carbon availability both through increased litter

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

    E-Print Network [OSTI]

    Sachs, Julian P.

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

  9. Design of Superconducting Parallel Bar Deflecting and Crabbing rf Structures

    SciTech Connect (OSTI)

    Jean Delayen, Haipeng Wang

    2009-05-01

    A new concept for a deflecting and crabbing rf structure based on half-wave resonant lines was introduced recently*. It offers significant advantages to existing designs and, because of it compactness, allows low frequency operation. This concept has been further refined and optimized for superconducting implementation. Results of this optimization and application to a 400 MHz crabbing cavity and a 499 MHz deflecting cavity are presented.

  10. High gradient rf gun studies of CsBr photocathodes

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

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10?? torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  11. Holographic Superconductors with the General $RF^2$-type Couplings

    E-Print Network [OSTI]

    Özcan Sert

    2015-07-25

    We explore the effects of the general non-minimally coupled $RF^2$-type couplings on the holographic superconductors numerically in the Schwarzschild-AdS background. We calculate the conductivity of the model and find that the increase of parameters $a_1$ and $\\beta$ lead to the lower gap frequency. Thus, we can obtain the weakly coupled BCS value $ \\omega_g/T_c \\approx 3.5$ for some coupling parameters of this model.

  12. Modeling rf breakdown arcs II: plasma / materials interactions

    E-Print Network [OSTI]

    Insepov, Zeke; Proslier, Thomas; Mahalingam, Sudhakar; Veitzer, S

    2010-01-01

    Continuing the description of rf vacuum arcs from an earlier paper, we describe some aspects of the interaction of vacuum arcs that involve the surface. This paper describes aspects of plasma materials interactions that affect the arc and models measurement of the surface field using the Tonks-Frenkel and the spinodal electrohydrodynamic instabilities, a realistic model for the generation and evaluation of high field enhancements, unipolar arcs, creep and other effects.

  13. Nano-electromechanical oscillators (NEMOs) for RF technologies.

    SciTech Connect (OSTI)

    Wendt, Joel Robert; Czaplewski, David A.; Gibson, John Murray (Argonne National Laboratory, Argonne, IL); Webster, James R.; Carton, Andrew James; Keeler, Bianca Elizabeth Nelson; Carr, Dustin Wade; Friedmann, Thomas Aquinas; Tallant, David Robert; Boyce, Brad Lee; Sullivan, John Patrick; Dyck, Christopher William; Chen, Xidong (Cedarville University, Cedarville, OH)

    2004-12-01

    Nano-electromechanical oscillators (NEMOs), capacitively-coupled radio frequency (RF) MEMS switches incorporating dissipative dielectrics, new processing technologies for tetrahedral amorphous carbon (ta-C) films, and scientific understanding of dissipation mechanisms in small mechanical structures were developed in this project. NEMOs are defined as mechanical oscillators with critical dimensions of 50 nm or less and resonance frequencies approaching 1 GHz. Target applications for these devices include simple, inexpensive clocks in electrical circuits, passive RF electrical filters, or platforms for sensor arrays. Ta-C NEMO arrays were used to demonstrate a novel optomechanical structure that shows remarkable sensitivity to small displacements (better than 160 fm/Hz {sup 1/2}) and suitability as an extremely sensitive accelerometer. The RF MEMS capacitively-coupled switches used ta-C as a dissipative dielectric. The devices showed a unipolar switching response to a unipolar stimulus, indicating the absence of significant dielectric charging, which has historically been the major reliability issue with these switches. This technology is promising for the development of reliable, low-power RF switches. An excimer laser annealing process was developed that permits full in-plane stress relaxation in ta-C films in air under ambient conditions, permitting the application of stress-reduced ta-C films in areas where low thermal budget is required, e.g. MEMS integration with pre-existing CMOS electronics. Studies of mechanical dissipation in micro- and nano-scale ta-C mechanical oscillators at room temperature revealed that mechanical losses are limited by dissipation associated with mechanical relaxation in a broad spectrum of defects with activation energies for mechanical relaxation ranging from 0.35 eV to over 0.55 eV. This work has established a foundation for the creation of devices based on nanomechanical structures, and outstanding critical research areas that need to be addressed for the successful application of these technologies have been identified.

  14. Holographic Superconductors with the General $RF^2$-type Couplings

    E-Print Network [OSTI]

    Sert, Özcan

    2015-01-01

    We explore the effects of the general non-minimally coupled $RF^2$-type couplings on the holographic superconductors numerically in the Schwarzschild-AdS background. We calculate the conductivity of the model and find that the increase of parameters $a_1$ and $\\beta$ lead to the lower gap frequency. Thus, we can obtain the weakly coupled BCS value $ \\omega_g/T_c \\approx 3.5$ for some coupling parameters of this model.

  15. Fractional conservation laws in optimal control theory

    E-Print Network [OSTI]

    Gastao S. F. Frederico; Delfim F. M. Torres

    2007-11-05

    Using the recent formulation of Noether's theorem for the problems of the calculus of variations with fractional derivatives, the Lagrange multiplier technique, and the fractional Euler-Lagrange equations, we prove a Noether-like theorem to the more general context of the fractional optimal control. As a corollary, it follows that in the fractional case the autonomous Hamiltonian does not define anymore a conservation law. Instead, it is proved that the fractional conservation law adds to the Hamiltonian a new term which depends on the fractional-order of differentiation, the generalized momentum, and the fractional derivative of the state variable.

  16. Local nonlinear rf forces in inhomogeneous magnetized plasmas

    SciTech Connect (OSTI)

    Chen, Jiale, E-mail: chen@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gao, Zhe [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

    2014-06-15

    The local nonlinear forces induced by radio frequency (rf) waves are derived in inhomogeneous magnetized plasmas, where the inhomogeneity exists in the rf fields, in the static magnetic field as well as in the equilibrium density and temperature. The local parallel force is completely resonant, but a novel component dependent on those inhomogeneities is obtained as the result of the inhomogeneous transport of parallel resonant-absorbed momentum by the nonlinear perpendicular drift flux. In the local poloidal force, the component induced by the inhomogeneity of rf power absorption is also confirmed and it can be recognized as the residual effect from the incomplete cancellation between the rate of the diamagnetic poloidal momentum gain and the Lorentz force due to the radial diffusion-like flux. The compact expression for radial force is also obtained for the first time, whose nonresonant component is expressed as the sum of the ponderomotive force on particles and the gradients of the nonresonant perpendicular pressure and of the nonresonant momentum flux due to the finite temperature effect. Numerical calculations in a 1-D slab model show that the resonant component dependent on the inhomogeneities may be significant when the ion absorption dominates the resonant wave-particle interaction. A quantitative estimation shows that the novel component in the parallel force is important to understand the experiments of the ion-cyclotron-frequency mode-conversion flow drive.

  17. RF Input Power Couplers for High Current SRF Applications

    SciTech Connect (OSTI)

    Khan, V. F.; Anders, W.; Burrill, Andrew; Knobloch, Jens; Kugeler, Oliver; Neumann, Axel; Wang, Haipeng

    2014-12-01

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

  18. A RF Lateral BJT on SOI for realization of RF SOI-BiCMOS I-Shan Michael Sun, Wai Tung Ng*, Hidenori Mochizuki, Koji Kanekiyo, Takaaki Kobayashi,

    E-Print Network [OSTI]

    Ng, Wai Tung

    A RF Lateral BJT on SOI for realization of RF SOI-BiCMOS Technology I-Shan Michael Sun, Wai Tung Ng between 190-300 GHz·V. The fmax of the optimal device reaches 46 GHz at collector current density of only vertical BJT requires thick- film SOI (>1µm) for the collector region, but is incompatible with thin

  19. Fractional Authorship in Nuclear Physics

    E-Print Network [OSTI]

    Pritychenko, B

    2015-01-01

    Large, multi-institutional groups or collaborations of scientists are engaged in nuclear physics research projects, and the number of research facilities is dwindling. These collaborations have their own authorship rules, and they produce a large number of highly-cited papers. Multiple authorship of nuclear physics publications creates a problem with the assessment of an individual author's productivity relative to his/her colleagues and renders ineffective a performance metrics solely based on annual publication and citation counts. Many institutions are increasingly relying on the total number of first-author papers; however, this approach becomes counterproductive for large research collaborations with an alphabetical order of authors. A concept of fractional authorship (the claiming of credit for authorship by more than one individual) helps to clarify this issue by providing a more complete picture of research activities. In the present work, nuclear physics fractional and total authorships have been inv...

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

    DOE Patents [OSTI]

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

    2013-01-15

    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.

  1. Performance of the high power rf system for the NIST--Los Alamos racetrack microtron

    SciTech Connect (OSTI)

    Cutler, R.I.; Young, L.

    1988-01-01

    The high power RF system of the NIST-LANL RTM has been tested at nominal full power levels and has accelerated electron beams successfully. RF stability and calibration measurements have been made using the accelerated electron beam. These measurements have been used to calculate the effective shunt impedance of the side- coupled accelerator structure. RF stability measurements were also performed using power meters and phase detectors. 7 refs., 4 figs.

  2. Stress-tolerant and temperature-stable RF MEMS capacitive switches and tunable filters

    E-Print Network [OSTI]

    Reines, Isak C.

    2010-01-01

    4.2 UCSD Switch Design . . . . . . . . . . . . . . .5.2 Switch Design . . . . . . . . . . . . . . .2.2 Switch Design in the Raytheon RF MEMS Process . . . . .

  3. Dependence of the microwave surface resistance of superconducting niobium on the magnitude of the rf field

    SciTech Connect (OSTI)

    Romanenko, A.; Grassellino, A. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

    2013-06-24

    Utilizing difference in temperature dependencies we decoupled Bardeen-Cooper-Schrieffer (BCS) and residual components of the microwave surface resistance of superconducting niobium at all rf fields up to B{sub rf}{approx}115 mT. We reveal that the residual resistance decreases with field at B{sub rf} Less-Than-Or-Equivalent-To 40 mT and strongly increases in chemically treated niobium at B{sub rf}>80 mT. We find that BCS surface resistance is weakly dependent on field in the clean limit, whereas a strong and peculiar field dependence emerges after 120 Degree-Sign C vacuum baking.

  4. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    MEMS switches for RF applications,” MicroelectromechanicalMEMS switch with a corrugated diaphragm,” MicroelectromechanicalMEMS switch technology for high frequency applications,” in Microelectromechanical

  5. Fractional Inversion in Krylov Space

    E-Print Network [OSTI]

    B. Bunk

    1998-05-28

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

  6. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect (OSTI)

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

    2014-02-12

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

  7. Fabrication Processes for the PEP II RF Cavities

    SciTech Connect (OSTI)

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

    2011-09-01

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

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

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

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

    2012-02-01

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

  9. Design Considerations for Future RF Circuits 1 Behzad Razavi

    E-Print Network [OSTI]

    Razavi, Behzad

    . I. INTRODUCTION The evolution of RF circuits has crossed an inflection point defined by two Current: 2 mA Conversion Gain: 5.4 dB NF: 8.2 dB IIP3: -3.8 dBm Supply Current: 2 mA Conversion Gain: 15 dB NF: 8.1 dB IIP3: +3.0 dBm 1 2 1 2 Fig. 1. (a) Active and (b) passive mixers operating with a 1-V

  10. Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds

    SciTech Connect (OSTI)

    Kuzikov, S. V.; Kazakov, S. Yu.; Jiang, Y.; Hirshfield, J. L.

    2010-05-28

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

  11. Surface Characterization of the LCLS RF Gun Cathode

    SciTech Connect (OSTI)

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

    2012-06-25

    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.

  12. Glass antenna for RF-ion source operation

    DOE Patents [OSTI]

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

    2000-01-01

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

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

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

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

    2012-02-01

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

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

    DOE Patents [OSTI]

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

    2002-01-01

    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.

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

    E-Print Network [OSTI]

    McCulley, Rebecca Lynne

    1998-01-01

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

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

    E-Print Network [OSTI]

    Vallino, Joseph J.

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

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

    E-Print Network [OSTI]

    Martin, Timothy

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

  18. Comparison of soil respiration methods in a mid-latitude deciduous forest

    SciTech Connect (OSTI)

    Wayson, C. A. [Indiana University; Randolph, J. C. [Indiana University; Hanson, Paul J [ORNL; Schmid, H. P. [Indiana University; Grimmond, CSB [Indiana University

    2006-01-01

    In forest ecosystems the single largest respiratory flux influencing net ecosystem productivity (NEP) is the total soil CO2 efflux; however, it is difficult to make measurements of this flux that are accurate at the ecosystem scale. We examined patterns of soil CO2 efflux using five different methods: auto-chambers, portable gas analyzers, eddy covariance along and two models parameterized with the observed data. The relation between soil temperature and soil moisture with soil CO2 effluxes are also investigated, both inter-annually and seasonally, using these observations/results. Soil respiration rates (Rsoil) are greatest during the growing season when soil temperatures are between 15 and 25 C, but some soil CO2 efflux occurs throughout the year. Measured soil respiration was sensitive to soil temperature, particularly during the spring and fall. All measurement methods produced similar annual estimates. Depending on the time of the year, the eddy covariance (flux tower) estimate for ecosystem respiration is similar to or slightly lower than estimates of annual soil CO2 efflux from the other methods. As the eddy covariance estimate includes foliar and stem respiration which the other methods do not; it was expected to be larger (perhaps 15-30%). The auto-chamber system continuously measuring soil CO2 efflux rates provides a level of temporalr esolution that permits investigation of short- to longer term influences of factors on these efflux rates. The expense of building and maintaining an auto chamber system may not be necessary for those esearchers interested in estimating Rsoil annually, but auto-chambers do allow the capture of data from all seasons needed for model parameterization.

  19. Time Fractional Formalism: Classical and Quantum Phenomena

    E-Print Network [OSTI]

    Hosein Nasrolahpour

    2012-03-18

    In this review, we present some fundamental classical and quantum phenomena in view of time fractional formalism. Time fractional formalism is a very useful tool in describing systems with memory and delay. We hope that this study can provide a deeper understanding of the physical interpretations of fractional derivative.

  20. Fractional quantum Hall effect and nonabelian statistics

    E-Print Network [OSTI]

    N. Read; G. Moore

    1992-02-03

    It is argued that fractional quantum Hall effect wavefunctions can be interpreted as conformal blocks of two-dimensional conformal field theory. Fractional statistics can be extended to nonabelian statistics and examples can be constructed from conformal field theory. The Pfaffian state is related to the 2D Ising model and possesses fractionally charged excitations which are predicted to obey nonabelian statistics.

  1. Localized Plasticity in the Streamlined Genomes of Vinyl Chloride Respiring Dehalococcoides

    SciTech Connect (OSTI)

    McMurdie, Paul J.; Behrens, Sebastien F.; Muller, Jochen A.; Goke, Jonathan; Ritalahti, Kirsti M.; Wagner, Ryan; Goltsman, Eugene; Lapidus, Alla; Holmes, Susan; Loffler, Frank E.; Spormann, Alfred M.

    2009-06-30

    Vinyl chloride (VC) is a human carcinogen and widespread priority pollutant. Here we report the first, to our knowledge, complete genome sequences of microorganisms able to respire VC, Dehalococcoides sp. strains VS and BAV1. Notably, the respective VC reductase encoding genes, vcrAB and bvcAB, were found embedded in distinct genomic islands (GEIs) with different predicted integration sites, suggesting that these genes were acquired horizontally and independently by distinct mechanisms. A comparative analysis that included two previously sequenced Dehalococcoides genomes revealed a contextually conserved core that is interrupted by two high plasticity regions (HPRs) near the Ori. These HPRs contain the majority of GEIs and strain-specific genes identified in the four Dehalococcoides genomes, an elevated number of repeated elements including insertion sequences (IS), as well as 91 of 96 rdhAB, genes that putatively encode terminal reductases in organohalide respiration. Only three core rdhA orthologous groups were identified, and only one of these groups is supported by synteny. The low number of core rdhAB, contrasted with the high rdhAB numbers per genome (up to 36 in strain VS), as well as their colocalization with GEIs and other signatures for horizontal transfer, suggests that niche adaptation via organohalide respiration is a fundamental ecological strategy in Dehalococccoides. This adaptation has been exacted through multiple mechanisms of recombination that are mainly confined within HPRs of an otherwise remarkably stable, syntenic, streamlined genome among the smallest of any free-living microorganism.

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

    E-Print Network [OSTI]

    Lanham, Jeffrey Kent

    1985-01-01

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

  3. Cancellation of RF Coupler-Induced Emittance Due to Astigmatism

    E-Print Network [OSTI]

    Dowell, David H

    2015-01-01

    It is well-known that the electron beam quality required for applications such as FELs and ultra-fast electron diffraction can be degraded by the asymmetric fields introduced by the RF couplers of superconducting linacs. This effect is especially troublesome in the injector where the low energy beam from the gun is captured into the first high gradient accelerator section. Unfortunately modifying the established cavity design is expensive and time consuming, especially considering that only one or two sections are needed for an injector. Instead, it is important to analyze the coupler fields to understand their characteristics and help find less costly solutions for their cancellation and mitigation. This paper finds the RF coupler-induced emittance for short bunches is mostly due to the transverse spatial sloping or tilt of the field, rather than the field's time-dependence. It is shown that the distorting effects of the coupler can be canceled with a static (DC) quadrupole lens rotated about the z-axis.

  4. RF System Modeling for the CEBAF Energy Upgrade

    SciTech Connect (OSTI)

    Tomasz Plawski, J. Hovater

    2009-05-01

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

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

    E-Print Network [OSTI]

    Qiang, J.

    2010-01-01

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

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

    E-Print Network [OSTI]

    Stancil, Daniel D.

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

  7. Balanced optical-microwave phase detector for sub-femtosecond optical-RF synchronization

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

    Peng, Michael Y.; Kalaydzhyan, Aram; Kärtner, Franz X.

    2014-10-23

    We demonstrate that balanced optical-microwave phase detectors (BOMPD) are capable of optical-RF synchronization with sub-femtosecond residual timing jitter for large-scale timing distribution systems. RF-to-optical synchronization is achieved with a long-term stability of more »suppression ratio with potential improvement via DC offset adjustment.« less

  8. Bio-implantable passive on-chip RF-MEMS strain sensing resonators for orthopaedic applications

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    Bio-implantable passive on-chip RF-MEMS strain sensing resonators for orthopaedic applications. Micromech. Microeng. 18 (2008) 115017 (9pp) doi:10.1088/0960-1317/18/11/115017 Bio-implantable passive on designed novel, bio-implantable, passive, on-chip, RF-MEMS strain sensors that rely on the resonance

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

    E-Print Network [OSTI]

    Yonehara, Katsuya

    2015-01-01

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

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

    SciTech Connect (OSTI)

    Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M.

    2011-12-23

    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.

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

    E-Print Network [OSTI]

    the arc discharge. Consider instead a non-emitting plasma cathode in which the plasma is produced by rfA Parametric Study of Electron Extraction from a Low Frequency Inductively Coupled RF-Plasma Source and Nathaniel J. Fisch 3 Princeton University Plasma Physics Laboratory, Princeton, NJ 08540, USA Abstract

  12. Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling and Design of RF MEMS Structures Using Computationally Efficient Numerical Techniques N. A Abstract The modeling of MEMS structures using MRTD is presented. Many complex RF structures have been communication systems efficiently and accurately. Specifically, micromachined structures such as MEMS

  13. Modeling of Large Scale RF-MEMS Circuits Using Efficient Time-Domain Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling of Large Scale RF-MEMS Circuits Using Efficient Time-Domain Techniques N. Bushyager, E Engineering Georgia Institute of Technology Atlanta, GA 30332-0250, USA Abstract RF-MEMS design is made difficult due to the lack of tools capable of simulating both MEMS devices and their surrounding circuits

  14. Ferroelectric PZT RF MEMS Resonators Jeffrey S. Pulskamp, Sarah S. Bedair, Ronald G.

    E-Print Network [OSTI]

    Afshari, Ehsan

    Ferroelectric PZT RF MEMS Resonators Jeffrey S. Pulskamp, Sarah S. Bedair, Ronald G. Polcawich- piezoelectric lead zirconate titanate (PZT) RF MEMS resonators. Several research topics are introduced including (~117dB) parallel resonant mode with DC bias tunable rejection, a MEMS support design for the mitigation

  15. Reliability of Capacitive RF MEMS Switches at High and Low Temperatures

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Reliability of Capacitive RF MEMS Switches at High and Low Temperatures Yong Zhu, Horacio D 60208-3111 Received 1 September 2003; accepted 24 February 2003 ABSTRACT: Some applications of RF MEMS temperatures in the range 60°C to 100°C are envisioned. The basic operation of a capacitive MEMS switch

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

    E-Print Network [OSTI]

    TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities F. Marhauser BESSY GmbH #12;TESLA FEL Report 200602 Contents 1. INTRODUCTION......................................................................................................................................................28 #12;TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities F

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

    E-Print Network [OSTI]

    Artuso, Florinda

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

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

    E-Print Network [OSTI]

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

    2012-01-06

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

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

    E-Print Network [OSTI]

    DeVience, Stephen J; Rosen, Matthew S

    2012-01-01

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

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

    DOE Patents [OSTI]

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

    1986-01-01

    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.

  1. Report of the survey realized at the TIARA workshop on RF power generation, Uppsala, 17-19 June 2013

    E-Print Network [OSTI]

    Tanguy, C.

    2013-01-01

    Report of the survey realized at the TIARA workshop on RF power generation, Uppsala, 17-19 June 2013

  2. Flow Field Flow Fractionation Method Development for Applied Bioanalysis

    E-Print Network [OSTI]

    Schachermeyer, Samantha Lynn

    2013-01-01

    E. ; Caldwell, K. , Field-Flow Fractionation Handbook. JohnJ. P. , Sedimentation field-flow-fractionation: emergence ofby sedimentation field-flow fractionation. Am. Lab. (

  3. Reflective Cracking Study: First-level Report on HVS Testing on Section 587RF - 45 mm RAC-G Overlay

    E-Print Network [OSTI]

    Wu, R; Jones, David; Harvey, John T

    2008-01-01

    Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-Testing on Section 588RF — 90 mm AR4000-D Overlay (UCPRC-RR-

  4. Reflective Cracking Study: First-level Report on HVS Testing on Section 586RF - 45 mm MB15-GOverlay

    E-Print Network [OSTI]

    Jones, David; Wu, R; Harvey, John T

    2008-01-01

    Testing on Section 590RF — 90 mm MB4-G Overlay (UCPRC-RR-Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-

  5. Reflective Cracking Study: First-Level Report on HVS Testing on Section 589RF - 45 mm MB4-G Overlay

    E-Print Network [OSTI]

    Jones, David; Harvey, John T; Wu, R; Lea, J.

    2008-01-01

    Testing on Section 590RF — 90 mm MB4-G Overlay (UCPRC-RR-Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-

  6. Reflective Cracking Study: First-Level Report on HVS Testing on Section 590RF - 90 mm MB4-G Overlay

    E-Print Network [OSTI]

    Jones, David; Tsai, Bor-Wen; Harvey, John T

    2008-01-01

    Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-Testing on Section 588RF — 90 mm AR4000-D Overlay (UCPRC-RR-Testing on Section 586RF — 45 mm MB15-G Overlay (UCPRC-RR-

  7. Reflective Cracking Study: First-level Report on HVS Testing on Section 588RF - 90 mm AR4000-DOverlay

    E-Print Network [OSTI]

    Jones, David; Wu, R; Harvey, John T

    2008-01-01

    Testing on Section 590RF — 90 mm MB4-G Overlay (UCPRC-RR-Testing on Section 589RF — 45 mm MB4-G Overlay (UCPRC-RR-Testing on Section 587RF — 45 mm RAC-G Overlay (UCPRC-RR-

  8. ON THE FREQUENCY SCALINGS OF RF GUNS Leon C.-L. Lin, J. S. Wurtele, and S. C. Chen

    E-Print Network [OSTI]

    Wurtele, Jonathan

    ON THE FREQUENCY SCALINGS OF RF GUNS Leon C.-L. Lin, J. S. Wurtele, and S. C. Chen Plasma Fusion Center Massachusetts Institute of Technology Abstract A frequency scaling law for RF guns is derived from the nor- malized Vlasov-Maxwell equations. It shows that higher fre- quency RF guns can generate higher

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

    E-Print Network [OSTI]

    Efficient Broadband RF Energy Harvesting for Wireless Sensors Joseph A. Hagerty, Tian Zhao, Regan. · the last section discusses application examples of RF energy harvesting in wireless sensors. RF Power an approach to wireless power delivery and subsequent power management for low-power batteryless sensors

  10. Simulations of the rf heating rates in a linear quadrupole ion trap Vladimir L. Ryjkov,* XianZhen Zhao,

    E-Print Network [OSTI]

    Schuessler, Hans

    Simulations of the rf heating rates in a linear quadrupole ion trap Vladimir L. Ryjkov,* Xian, trapping voltage, and the number of ions is studied. The dependence of rf heating rate on temperature shows. The rf heating rate is shown to increase very sharply with the amplitude of the trapping voltage

  11. Low Actuation Voltage RF MEMS SwitchesWith Signal Frequencies From 0.25GHz to 40GHz

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    Low Actuation Voltage RF MEMS SwitchesWith Signal Frequencies From 0.25GHz to 40GHz Shyh-voltage radio-frequency micro- electromechanical system (RF MEMS) switch is reported. The device switching of better than 27 dB over the frequency band from 0.25GHz to 40GHz was achieved. The RF MEMS switch

  12. Reconfigurable Multi-Beam Spiral Antenna with RF-MEMS Capacitive Series Switches Fabricated on Rigid Substrates

    E-Print Network [OSTI]

    De Flaviis, Franco

    Reconfigurable Multi-Beam Spiral Antenna with RF-MEMS Capacitive Series Switches Fabricated antenna, which radiates multi-beam with radio frequency-micro electro mechanical system (RF-MEMS.8). The spiral is configured by three-arms, which can be interconnected by two RF-MEMS series switches

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

    E-Print Network [OSTI]

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

  14. Superconducting DC and RF Properties of Ingot Niobium

    SciTech Connect (OSTI)

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

    2011-07-01

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

  15. RF and structural characterization of new SRF films

    SciTech Connect (OSTI)

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

    2009-09-01

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

  16. 1.3 GHz superconducting RF cavity program at Fermilab

    SciTech Connect (OSTI)

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

    2011-03-01

    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.

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

    E-Print Network [OSTI]

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

    2015-01-01

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

  18. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    SciTech Connect (OSTI)

    Poole, B R; Harris, J R

    2011-03-07

    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.

  19. National RF Test Facility as a multipurpose development tool

    SciTech Connect (OSTI)

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

    1983-01-01

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

  20. A new microphonics measurement method for superconducting RF cavities

    SciTech Connect (OSTI)

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

    2014-09-01

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

  1. WATER FRACTIONS IN EXTRASOLAR PLANETESIMALS

    SciTech Connect (OSTI)

    Jura, M.; Xu, S., E-mail: jura@astro.ucla.edu, E-mail: sxu@astro.ucla.edu [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1562 (United States)

    2012-01-15

    With the goal of using externally polluted white dwarfs to investigate the water fractions of extrasolar planetesimals, we assemble from the literature a sample that we estimate to be more than 60% complete of DB white dwarfs warmer than 13,000 K, more luminous than 3 Multiplication-Sign 10{sup -3} L{sub Sun }, and within 80 pc of the Sun. When considering all the stars together, we find that the summed mass accretion rate of heavy atoms exceeds that of hydrogen by over a factor of 1000. If so, this sub-population of extrasolar asteroids treated as an ensemble has little water and is at least a factor of 20 drier than CI chondrites, the most primitive meteorites. Furthermore, while an apparent 'excess' of oxygen in a single DB can be interpreted as evidence that the accreted material originated in a water-rich parent body, we show that at least in some cases, there can be sufficient uncertainties in the time history of the accretion rate that such an argument may be ambiguous. Regardless of the difficulty associated with interpreting the results from an individual object, our analysis of the population of polluted DBs provides indirect observational support for the theoretical view that a snow line is important in disks where rocky planetesimals form.

  2. Riemann-Liouville Fractional Einstein Field Equations

    E-Print Network [OSTI]

    Joakim Munkhammar

    2010-03-18

    In this paper we establish a fractional generalization of Einstein field equations based on the Riemann-Liouville fractional generalization of the ordinary differential operator $\\partial_\\mu$. We show some elementary properties and prove that the field equations correspond to the regular Einstein field equations for the fractional order $\\alpha = 1$. In addition to this we show that the field theory is inherently non-local in this approach. We also derive the linear field equations and show that they are a generalized version of the time fractional diffusion-wave equation. We show that in the Newtonian limit a fractional version of Poisson's equation for gravity arises. Finally we conclude open problems such as the relation of the non-locality of this theory to quantum field theories and the possible relation to fractional mechanics.

  3. Review of Some Promising Fractional Physical Models

    E-Print Network [OSTI]

    Vasily E. Tarasov

    2015-02-14

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

  4. WEIGHTED NORM INEQUALITIES FOR FRACTIONAL MAXIMAL ...

    E-Print Network [OSTI]

    2013-11-19

    We study classical weighted Lp ? Lq inequalities for the fractional max- imal operators on Rd, proved originally by Muckenhoupt and Wheeden in the 70's. We

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

    SciTech Connect (OSTI)

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

    2010-12-15

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

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

    E-Print Network [OSTI]

    Vega C., Eduardo Humberto

    1957-01-01

    GMV 'KLl% NOIXVEIdSZH ZHflLVKEcBCiU 'IVLVK ar SZONVK ZrZVa n urrISVZIXe SSX THE HERITABILITY QF DAILT RANGES IR RECTAL TRAPE3ATCRE y HE V IRATI CR RATE & AHD PULSE RATE IR LACTATIlgl CCHH A Thesis Muardo Susbarto Vega C Appreved as to style... for the Daily Ranges of Tem- perature, Pulse Rate? snd Respiration Rate of Holsteins and Jerseys Prior to Adjustmsnt . ~ ~ ~ 13 IXX, Beans? Standard Errors, and Nunber of Observations for the Three Chax'aeter istics Beasuxed, After Adjustment ~ ~ ~ ~ ~ 13...

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

    SciTech Connect (OSTI)

    Larsen, R

    2009-10-17

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

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

    E-Print Network [OSTI]

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

    2015-01-01

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

  9. Commissioning of the LHC Low Level RF System Remote Configuration Tools

    SciTech Connect (OSTI)

    Van Winkle, Daniel; /SLAC; Fox, John; /SLAC; Mastorides, Themis; /SLAC; Rivetta, Claudio; /SLAC; Baudrenghien, Philippe; /CERN; Butterworth, Andrew; /CERN; Molendijk, John; /CERN

    2010-08-26

    The LHC Low Level RF system (LLRF) is a complex multi-loop system used to regulate the superconductive cavity gap voltage as well as to reduce the impedance presented by RF stations to the beam. The RF system can have a profound impact on the stability of the beam; a mis-configured RF system has the potential of causing longitudinal instabilities, beam diffusion and beam loss. To configure the RF station for operation, a set of parameters in the LLRF multi-loop system have to be defined. Initial system commissioning as well as ongoing operation requires a consistent method of computer based remote measurement and model-based design of each RF station feedback system. This paper describes the suite of Matlab tools used for configuring the LHC RF system during the start up in Nov2009-Feb2010. We present a brief overview of the tool, examples of commissioning results, and basics of the model-based design algorithms. This work complements our previous presentation, where the algorithms and methodology followed in the tools were described.

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

    SciTech Connect (OSTI)

    Chung, M.; et al.

    2013-10-01

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

  11. OPTIMIZING OF SUMS AND PRODUCTS OF LINEAR FRACTIONAL FUNCTIONS

    E-Print Network [OSTI]

    OPTIMIZING OF SUMS AND PRODUCTS OF LINEAR FRACTIONAL FUNCTIONS UNDER LINEAR CONSTRAINTS JOACHIM of two linear fractional functions under linear constraints. Results of computational experiments. Fractional programming, composite objective functions, linear fractional functions, Charnes

  12. Devices, systems, and methods for microscale isoelectric fractionation...

    Office of Scientific and Technical Information (OSTI)

    and methods for microscale isoelectric fractionation Embodiments of the present invention provide devices, systems, and methods for microscale isoelectric fractionation....

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

    DOE Patents [OSTI]

    Kwan, Joe; Ji, Qing

    2014-05-20

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

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

    SciTech Connect (OSTI)

    Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro; Hayano, Hitoshi; Urakawa, Junji

    2010-02-03

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

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

    SciTech Connect (OSTI)

    Tighe, R.; /SLAC

    2011-08-31

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

  16. RF system considerations for accelerator production of tritium and the transmutation of nuclear waste

    SciTech Connect (OSTI)

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

    1993-11-01

    RF driven proton accelerators for the transmutation of nuclear waste (ATW) or for the production of tritium (APT) require unprecedented amounts of CW RF power at UHF frequencies. For both systems, the baseline design is for 246 MW at 700 MHz and 8,5 MW at 350 MHz. The main technical challenges are how to design and build such a large system so that it has excellent reliability, high efficiency, and reasonable capital cost. The issues associated with the selection of the RF amplifier and the sizes of the power supplies are emphasized in this paper.

  17. Laser cooling and sympathetic cooling in a linear quadrupole rf trap 

    E-Print Network [OSTI]

    Ryjkov, Vladimir Leonidovich

    2005-02-17

    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 mecha- nisms 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 io- dine has...

  18. [Carbon isotope fractionation inplants]. Final report

    SciTech Connect (OSTI)

    O`Leary, M.H.

    1990-12-31

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

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

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

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

    2015-04-13

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

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

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

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

    2015-04-13

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

  1. Fast kinase domain-containing protein 3 is a mitochondrial protein essential for cellular respiration

    SciTech Connect (OSTI)

    Simarro, Maria; Gimenez-Cassina, Alfredo; Kedersha, Nancy; Lazaro, Jean-Bernard; Adelmant, Guillaume O.; Marto, Jarrod A.; Rhee, Kirsten; Tisdale, Sarah; Danial, Nika; Benarafa, Charaf; Orduna, Anonio; Anderson, Paul

    2010-10-22

    Research highlights: {yields} Five members of the FAST kinase domain-containing proteins are localized to mitochondria in mammalian cells. {yields} The FASTKD3 interactome includes proteins involved in various aspects of mitochondrial metabolism. {yields} Targeted knockdown of FASTKD3 significantly reduces basal and maximal mitochondrial oxygen consumption. -- Abstract: Fas-activated serine/threonine phosphoprotein (FAST) is the founding member of the FAST kinase domain-containing protein (FASTKD) family that includes FASTKD1-5. FAST is a sensor of mitochondrial stress that modulates protein translation to promote the survival of cells exposed to adverse conditions. Mutations in FASTKD2 have been linked to a mitochondrial encephalomyopathy that is associated with reduced cytochrome c oxidase activity, an essential component of the mitochondrial electron transport chain. We have confirmed the mitochondrial localization of FASTKD2 and shown that all FASTKD family members are found in mitochondria. Although human and mouse FASTKD1-5 genes are expressed ubiquitously, some of them are most abundantly expressed in mitochondria-enriched tissues. We have found that RNA interference-mediated knockdown of FASTKD3 severely blunts basal and stress-induced mitochondrial oxygen consumption without disrupting the assembly of respiratory chain complexes. Tandem affinity purification reveals that FASTKD3 interacts with components of mitochondrial respiratory and translation machineries. Our results introduce FASTKD3 as an essential component of mitochondrial respiration that may modulate energy balance in cells exposed to adverse conditions by functionally coupling mitochondrial protein synthesis to respiration.

  2. LANGEVIN SIMULATION OF RF CORONA DISCHARGES FOR SPACE HARDWARE M. Alfonseca(1)

    E-Print Network [OSTI]

    Alfonseca, Manuel

    is an electric breakdown process at low neutral gas pressures originated by the progressive outgassing neutral gas pressures lower than ground levels, caused by the progressive outgassing of the entire RF

  3. Understanding and Mitigating the Impact of RF Interference on 802.11 Networks

    E-Print Network [OSTI]

    Abstract We study the impact on 802.11 networks of RF interference from devices such as Zigbee and cordless that includes 2.4GHz cordless phones, Bluetooth headsets, Zigbee Work done while the author was at Intel

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

    E-Print Network [OSTI]

    Purdue University

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

  5. Analysis of slice transverse emittance evolutioin in a photocathode RF gun

    E-Print Network [OSTI]

    Huang, Zhirong

    2009-01-01

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

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

    E-Print Network [OSTI]

    Baptiste, Kenneth

    2009-01-01

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

  7. A high-gradient high-duty-factor Rf photo-cathode electron gun

    E-Print Network [OSTI]

    Rimmer, Robert A.; Hartman, Neal; Lidia, Steven M.; Wang, Shaoheng

    2002-01-01

    approximately 13 MV/m, but in the gun cell the fields couldBeam Radius [mm] End of rf gun Uncompensated Compensated 6preliminary analysis of the gun indicates that the fields in

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

    SciTech Connect (OSTI)

    Xiao, Binping; Reece, Charles E.

    2014-02-01

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

  9. Deeply-scaled GaN high electron mobility transistors for RF applications

    E-Print Network [OSTI]

    Lee, Dong Seup

    2014-01-01

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

  10. Medium Power 352 MHZ solid state pulsed RF amplifiers for the CERN LINAC4 Project

    E-Print Network [OSTI]

    Broere, J; Gómez Martínez, Y; Rossi, M

    2011-01-01

    Economic, modular and highly linear pulsed RF amplifiers have recently been developed to be used for the three buncher cavities in the CERN Linac4. The amplifiers are water-cooled and can provide up to 33 kW pulsed RF Power, 1.5 ms pulse length and 50 Hz repetition rate. Furthermore a 60 kW unit is under construction to provide the required RF Power for the debuncher cavity. The concept is based on 1.2 kW RF power modules using the latest 6th generation LDMOS technology. For integration into the CERN control environment the amplifiers have an internal industrial controller, which will provide easy control and extended diagnostic functions. This paper describes the construction, performance, including linearity, phase stability and EMC compliance tests

  11. Novel RF/Microwave Circuits And Systems for Lab on-Chip/on-Board Chemical Sensors 

    E-Print Network [OSTI]

    Abbas Mohamed Helmy, Ahmed M

    2013-08-02

    Recent research focuses on expanding the use of RF/Microwave circuits and systems to include multi-disciplinary applications. One example is the detection of the dielectric properties of chemicals and bio-chemicals at ...

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

    E-Print Network [OSTI]

    Baptiste, Kenneth

    2009-01-01

    RF power for 750 kV Peak wall power density Stored energyimpedance, to minimize the wall power density, to reduce theresulting modest power load on the walls is compatible with

  13. A photocathode rf gun design for a mm-wave linac-based FEL

    SciTech Connect (OSTI)

    Nassiri, A.; Berenc, T,; Foster, J.; Waldschmidt, G.; Zhou, J.

    1995-07-01

    In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths ({approximately}300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell {pi}-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure.

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

    E-Print Network [OSTI]

    Park, Sanghoon

    2005-11-01

    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 ...

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

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01

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

  16. Modeling and Simulation of the Longitudinal Beam Dynamics - RF Station Interaction in the LHC Rings

    SciTech Connect (OSTI)

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

    2008-07-07

    A non-linear time-domain simulation has been developed to study the interaction between longitudinal beam dynamics and RF stations in the LHC rings. The motivation for this tool is to determine optimal LLRF configurations, to study system sensitivity on various parameters, and to define the operational and technology limits. It will be also used to study the effect of RF station noise, impedance, and perturbations on the beam life time and longitudinal emittance. It allows the study of alternative LLRF implementations and control algorithms. The insight and experience gained from our PEP-II simulation is important for this work. In this paper we discuss properties of the simulation tool that will be helpful in analyzing the LHC RF system and its initial results. Partial verification of the model with data taken during the LHC RF station commissioning is presented.

  17. Proposal for an RF roadmap towards Ultimate Intensity in the LHC

    E-Print Network [OSTI]

    Baudrenghien, P

    2012-01-01

    The LHC currently operates with 1380 bunches at 50 ns spacing and 1.4 1011 p per bunch (0.35A DC). In this paper the RF operation with ultimate bunch intensity (1.7 1011 p per bunch) and 25 ns spacing (2808 bunches per beam) summing up to 0.86A DC is presented. With the higher beam current, the demanded klystron power will be increased and the longitudinal stability margin reduced. One must also consider the impact of a klystron trip (voltage and power transients in the three turns latency before the beam is actually dumped). In this work a scheme is proposed that can deal with ultimate bunch intensity. Only a minor upgrade of the Low Level RF is necessary: the field set point will be modulated according to the phase shift produced by the transient beam loading, thus minimizing the RF power while keeping the strong feedback for stability and reduction of the RF noise.

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

    E-Print Network [OSTI]

    Wadley, Haydn

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

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

    E-Print Network [OSTI]

    Armendariz, Marcelino

    2012-02-14

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

  20. PHYSICAL REVIEW A 90, 012504 (2014) Atomic properties of superheavy elements No, Lr, and Rf

    E-Print Network [OSTI]

    Safronova, Marianna

    2014-01-01

    available. Similar calculations for lighter analogs, ytterbium, lutetium, and hafnium, are used to study are heavier analogs of ytterbium, lutetium, and hafnium. No, Lr, and Rf were studied theoretically

  1. A Wireless Sensing Platform Utilizing Ambient RF Energy Aaron N. Parks 1

    E-Print Network [OSTI]

    Hochberg, Michael

    , such as a battery or supercapacitor, to deal with the blackout period in which its energy source is not available. An RF harvesting node typically need not deal with such a blackout period, and therefore does not need

  2. Highly Parallel Magnetic Resonance Imaging with a Fourth Gradient Channel for Compensation of RF Phase Patterns 

    E-Print Network [OSTI]

    Bosshard, John 1983-

    2012-08-20

    A fourth gradient channel was implemented to provide slice dependent RF coil phase compensation for arrays in dual-sided or "sandwich" configurations. The use of highly parallel arrays for single echo acquisition magnetic resonance imaging allows...

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

    DOE Patents [OSTI]

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

    1980-08-26

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

  4. Design of RF/IF analog to digital converters for software radio communication receivers 

    E-Print Network [OSTI]

    Thandri, Bharath Kumar

    2007-09-17

    Software radio architecture can support multiple standards by performing analogto- digital (A/D) conversion of the radio frequency (RF) signals and running reconfigurable software programs on the backend digital signal ...

  5. In situ RF/microwave remediation of soil benchtop experiment overview and results

    SciTech Connect (OSTI)

    Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T.

    1996-06-01

    The authors have developed an in-situ process that combines RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove soil contaminants. They have conducted a number of benchtop experiments involving RF/microwave energy deposition and vapor extraction on controlled contaminated soil samples with successful removal of the DNAPL contaminants. This paper will describe the experiments performed and present results.

  6. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    E-Print Network [OSTI]

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  7. Klystron Cluster Scheme for ILC High Power RF Distribution

    SciTech Connect (OSTI)

    Nantista, Christopher; Adolphsen, Chris; /SLAC

    2009-07-06

    We present a concept for powering the main linacs of the International Linear Collider (ILC) by delivering high power RF from the surface via overmoded, low-loss waveguides at widely spaced intervals. The baseline design employs a two-tunnel layout, with klystrons and modulators evenly distributed along a service tunnel running parallel to the accelerator tunnel. This new idea eliminates the need for the service tunnel. It also brings most of the warm heat load to the surface, dramatically reducing the tunnel water cooling and HVAC requirements. In the envisioned configuration, groups of 70 klystrons and modulators are clustered in surface buildings every 2.5 km. Their outputs are combined into two half-meter diameter circular TE{sub 01} mode evacuated waveguides. These are directed via special bends through a deep shaft and along the tunnel, one upstream and one downstream. Each feeds approximately 1.25 km of linac with power tapped off in 10 MW portions at 38 m intervals. The power is extracted through a novel coaxial tap-off (CTO), after which the local distribution is as it would be from a klystron. The tap-off design is also employed in reverse for the initial combining.

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

    SciTech Connect (OSTI)

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

    2011-09-01

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

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

    E-Print Network [OSTI]

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

    2013-11-13

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

  10. Linear and multilinear fractional operators: weighted inequalities, sharp bounds, and other properties

    E-Print Network [OSTI]

    Moen, Kabe

    2009-04-27

    In this work we consider various fractional operators, including the classical fractional integral operators, related fractional maximal functions, multilinear fractional integral operators, and multisublinear fractional ...

  11. Integral equations, fractional calculus and shift operator

    E-Print Network [OSTI]

    D. Babusci; G. Dattoli; D. Sacchetti

    2010-07-29

    We present an extension of a previously developed method employing the formalism of the fractional derivatives to solve new classes of integral equations. This method uses different forms of integral operators that generalizes the exponential shift operator.

  12. Bio-oil fractionation and condensation

    DOE Patents [OSTI]

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

    2013-07-02

    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.

  13. Algebra of Fractions of Algebra with Conjugation

    E-Print Network [OSTI]

    Aleks Kleyn

    2012-05-09

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

  14. Unconventional Sequence of Fractional Quantum Hall

    E-Print Network [OSTI]

    Yacoby, Amir

    Unconventional Sequence of Fractional Quantum Hall States in Suspended Graphene Benjamin E. Feldman- netic field B to a two-dimensional elec- tron gas (2DEG) gives rise to flat energy bands called Landau

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

    SciTech Connect (OSTI)

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

    2011-01-01

    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.

  16. Extending Bauer's corollary to fractional derivatives

    E-Print Network [OSTI]

    David W. Dreisigmeyer; Peter M. Young

    2004-02-11

    We comment on the method of Dreisigmeyer and Young [D. W. Dreisigmeyer and P. M. Young, J. Phys. A \\textbf{36}, 8297, (2003)] to model nonconservative systems with fractional derivatives. It was previously hoped that using fractional derivatives in an action would allow us to derive a single retarded equation of motion using a variational principle. It is proven that, under certain reasonable assumptions, the method of Dreisigmeyer and Young fails.

  17. Development of plutonium aerosol fractionation system 

    E-Print Network [OSTI]

    Mekala, Malla R.

    1993-01-01

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

  18. Prescribed burning and mechanical thinning effects on belowground conditions and soil respiration in a mixed-conifer forest, California

    E-Print Network [OSTI]

    Chen, Jiquan

    Prescribed burning and mechanical thinning effects on belowground conditions and soil respiration. Introduction Carbon storage in belowground biomass is twice that of atmospheric carbon (C), and soil; Raich and Potter, 1995; Janssens et al., 2001; Lal, 2008). More specifically, forest soils contain about

  19. Vanderbilt Environmental Health and Safety Revised: 6/14/2012 Respirator Fit-Testing and Staff with Facial Hair

    E-Print Network [OSTI]

    Wikswo, John

    that comes between the sealing surface of the facepiece and the face or that interferes with valve function, or extend far enough to interfere with the device's function (such as the interference with valve function, there is no consistency to respirator fit, and there is higher leakage. OSHA Citation Guidelines http://www.osha.gov/pls

  20. TRANSPORT OF WATER BY THE GILLS AND RESPIRATION ~Tl'l\\llSpoTt of watel'_____ ____ ___ ____ _ _____ _ _ 185

    E-Print Network [OSTI]

    CHAPTER IX TRANSPORT OF WATER BY THE GILLS AND RESPIRATION ~Tl'l\\llSpoTt of watel Reduction of water transport.______ 196 Dls80lved organic aubstances and rate of water transpor- tion, respiratory current, and feeding. When "feeding" is used in reference to the transport of water

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

    E-Print Network [OSTI]

    Oren, Ram

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

  2. Summary In shaded environments, minimizing dark respi-ration during growth could be an important aspect of maintain-

    E-Print Network [OSTI]

    Machado, Jose-Luis

    Summary In shaded environments, minimizing dark respi- ration during growth could be an important aspect of maintain- ing a positive whole-plant net carbon balance. Changes with plant size in both (Kraus et al. 1989, Tjoelker et al. 1999a). In deeply shaded environments, dark respiration is likely

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

    E-Print Network [OSTI]

    Matthews, Adrian

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

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

    E-Print Network [OSTI]

    Pedersen, Tom

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

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

    E-Print Network [OSTI]

    Wang, Xudong

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

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

    SciTech Connect (OSTI)

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

    2012-11-26

    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

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

    SciTech Connect (OSTI)

    Isaksson, Marcus; Jalden, Joakim; Murphy, Martin J.

    2005-12-15

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

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

    SciTech Connect (OSTI)

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

    2007-01-01

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

  9. Effect of moisture on leaf litter decomposition and its contribution to soil respiration in a temperate forest

    SciTech Connect (OSTI)

    Cisneros-Dozal, Luz Maria; Trumbore, Susan E.; Hanson, Paul J

    2007-01-01

    The degree to which increased soil respiration rates following wetting is caused by plant (autotrophic) versus microbial (heterotrophic) processes, is still largely uninvestigated. Incubation studies suggest microbial processes play a role but it remains unclear whether there is a stimulation of the microbial population as a whole or an increase in the importance of specific substrates that become available with wetting of the soil. We took advantage of an ongoing manipulation of leaf litter 14C contents at the Oak Ridge Reservation, Oak Ridge, Tennessee, to (1) determine the degree to which an increase in soil respiration rates that accompanied wetting of litter and soil, following a short period of drought, could be explained by heterotrophic contributions; and (2) investigate the potential causes of increased heterotrophic respiration in incubated litter and 0-5 cm mineral soil. The contribution of leaf litter decomposition increased from 6 3 mg C m 2 hr 1 during a transient drought, to 63 18 mg C m 2 hr 1 immediately after water addition, corresponding to an increase in the contribution to soil respiration from 5 2% to 37 8%. The increased relative contribution was sufficient to explain all of the observed increase in soil respiration for this one wetting event in the late growing season. Temperature (13 C versus 25 C) and moisture (dry versus field capacity) conditions did not change the relative contributions of different decomposition substrates in incubations, suggesting that more slowly cycling C has at least the same sensitivity to decomposition as faster cycling organic C at the temperature and moisture conditions studied.

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

    SciTech Connect (OSTI)

    Jensen, Nikolaj K. G.; Stewart, Errol; Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7; Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 ; Lock, Michael; Fisher, Barbara; Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 ; Kozak, Roman; Chen, Jeff; Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6; Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 ; Lee, Ting-Yim; Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7; Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5; Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6; Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 ; Wong, Eugene; Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6; Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1; Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7

    2014-05-15

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

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

    E-Print Network [OSTI]

    Wu, Ying

    2010-01-01

    compact RF-driven neutron generator Los Alamos NationalSource for a Neutron Generator Used For Associated Particleprototype compact neutron generator for associated particle

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

    SciTech Connect (OSTI)

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

    1996-02-01

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

  13. On sampling fractions and electron shower shapes

    SciTech Connect (OSTI)

    Peryshkin, Alexander; Raja, Rajendran; /Fermilab

    2011-12-01

    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.

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

    SciTech Connect (OSTI)

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

    2009-04-01

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

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

    SciTech Connect (OSTI)

    Romanov, Gennady; Kashikhin, Vladimir; /Unlisted

    2010-09-01

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

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

    SciTech Connect (OSTI)

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

    2014-12-01

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

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

    SciTech Connect (OSTI)

    Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

    2012-05-01

    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.

  18. Modeling the ion density distribution in collisional cooling RF multipole ion guides

    SciTech Connect (OSTI)

    Tolmachev, Aleksey V.; Udseth, Harold R.; Smith, Richard D.

    2003-01-01

    Collisional cooling radio frequency (RF) multipoles are widely used in mass spectrometry, as ion guides and two-dimensional (2D) ion traps. Understanding the behavior of ions in these devices is important in choosing a multipole configuration. We have developed a computer model based on ion trajectory calculations in the RF multipole electric field, taking into account ion-ion and ion-neutral interactions. The two-dimensional model for idealized infinite RF multipoles gives accurate description of the ion density distribution. We consider first a basic case of a single m/z ion cloud in the 2D RF quadrupole after equilibrium is reached. Approximate theoretical relationships for the ion cloud configuration in the 2D ion trap are tested based on simulations results. Next we proceed with a case of an ion cloud consisting of several different m/z ion species. The ion relaxation dynamics and the process of establishing the stratified ion density distribution are followed. Simulations reveal a different relaxation dynamics for the axial and radial ion kinetic energy components. The kinetic energy relaxation rate is dependent on ion population and bath gas pressure. The equilibrium distribution agrees well with the ion stratification theory, as demonstrated by simulations for RF quadrupole and octupole 2D ion traps.

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

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

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

  20. Fractional Topological Phases and Broken Time-Reversal Symmetry...

    Office of Scientific and Technical Information (OSTI)

    Fractional Topological Phases and Broken Time-Reversal Symmetry in Strained Graphene Prev Next Title: Fractional Topological Phases and Broken Time-Reversal Symmetry in...

  1. Intake fraction of nonreactive vehicle emissions in US urban areas

    E-Print Network [OSTI]

    Marshall, J D; Teoh, S K; Nazaroff, William W

    2005-01-01

    fraction of nonreactive vehicle emissions JD Marshall et al.and trends in motor vehicle emissions to monthly urbanExposure to motor vehicle emissions: An intake fraction

  2. Carbon isotope fractionation in autotrophic Chromatium 

    E-Print Network [OSTI]

    Wong, William Wai-Lun

    1974-01-01

    . 8 and -27. 8 o/oo respect- 13 PDB ively. Fructose and glucose separated from the sugar fraction have an identical 6 C value of -21. 8 o/oo; 13 whereas aspartic acid, glutamic acid and alanine separated from the amino acid fraction have 6PDBC... ACETYL- Ca A F UKIARATE CITRATE ATP CO ATP DPNH 2 1 I TPNH CO GLYOX SUCCINATE ISOCITRATE YLATE + GLUTAMATE 16 led POLLER et al. (1961) and LOSADA et al. (1960) to believe that PEP carboxvlase is also active in the bacterium during...

  3. Selecting Fractionators for Product Composition Control 

    E-Print Network [OSTI]

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

    1979-01-01

    FRACTIONATORS FOR PRODUCT COMPOSITION CONTROL D. E. Griffin and J. E. Anderson Applied Automation, Inc. Pawhuska Road Bartlesville, OK 74004 ABSTRACT The benefits resulting from computer control of fractionators have been proven in many installations... Progress 74,4, pp. 49-55. 3. Smith, D. E., W. S. Stewart and D. E. Griffin, February, 1978, "Distill With Composition Control, "Hydrocarbon Processing 57, 2, pp. 99-107. 4. Griffin, D. E., J. R. Parsons and D. E. Smith, "The Use of Process Analyzers...

  4. The Fractional Kinetic Equation and Thermonuclear Functions

    E-Print Network [OSTI]

    H. J. Haubold; A. M. Mathai

    2000-01-16

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

  5. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

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

    Chase, B.; Pasquinelli, R.; Cullerton, E.; Varghese, P.

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRFmore »cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.« less

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

    SciTech Connect (OSTI)

    McGuire, Gary; Martin, Allen; Noonan, John

    2010-10-30

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

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

    E-Print Network [OSTI]

    Brian Chase; Ralph Pasquinelli; Ed Cullerton; Philip Varghese

    2014-11-21

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

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

    E-Print Network [OSTI]

    Chase, Brian; Cullerton, Ed; Varghese, Philip

    2015-01-01

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

  9. Confinement improvement with rf poloidal current drive in the reversed-field pinch

    SciTech Connect (OSTI)

    Hokin, S.; Sarff, J.; Sovinec, C.; Uchimoto, E.

    1994-03-08

    External control of the current profile in a reversed-field pinch (RFP), by means such as rf poloidal current drive, may have beneficial effects well beyond the direct reduction of Ohmic input power due to auxiliary heating. Reduction of magnetic turbulence associated with the dynamo, which drives poloidal current in a conventional RFP, may allow operation at lower density and higher electron temperature, for which rf current drive becomes efficient and the RFP operates in a more favorable regime on the n{tau} vs T diagram. Projected parameters for RFX at 2 MA axe studied as a concrete example. If rf current drive allows RFX to operate with {beta} = 10% (plasma energy/magnetic energy) at low density (3 {times} 10{sup 19} m{sup {minus}3}) with classical resistivity (i.e. without dynamo-enhanced power input), 40 ms energy confinement times and 3 keV temperatures will result, matching the performance of tokamaks of similar size.

  10. Hamilton-Jacobi Fractional Sequential Mechanics

    E-Print Network [OSTI]

    Eqab M. Rabei; Bashar S. Ababneh

    2007-04-04

    As a continuation of Rabei et al. work [11], the Hamilton- Jacobi partial differential equation is generalized to be applicable for systems containing fractional derivatives. The Hamilton- Jacobi function in configuration space is obtained in a similar manner to the usual mechanics. Two problems are considered to demonstrate the application of the formalism. The result found to be in exact agreement with Agrawal's formalism.

  11. Measurement of the D -> pipi branching fractions

    E-Print Network [OSTI]

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

    1993-09-01

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

  12. Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

    SciTech Connect (OSTI)

    Burrill,A.

    2009-01-01

    The 56 MHz cavity presents a unique challenge in preparing it for RF testing prior to construction of the cryomodule. This challenge arises due to the physical dimensions and subsequent weight of the cavity, and is further complicated by the coaxial geometry, and the need to properly chemically etch and high pressure rinse the entire inner surface prior to RF testing. To the best of my knowledge, this is the largest all niobium SRF cavity to be chemically etched and subsequently tested in a vertical dewar at 4K, and these processes will be the topic of this technical note.

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

    SciTech Connect (OSTI)

    Bosch, Robert; Legg, Robert A.

    2013-12-01

    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.

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

    E-Print Network [OSTI]

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

    2015-01-01

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

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

    E-Print Network [OSTI]

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

    2008-01-01

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

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

    DOE Patents [OSTI]

    Norem, James H.; Pellin, Michael J.

    2013-06-11

    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.

  17. Modeling RF Passive Circuits using Coupled Lines and Scalable Models Sidharth Dalmia, Sung Hwan Min and Madhavan Swaminathan

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    the building blocks for other passive structures such as spiral inductors, transformers and capacitors [1Modeling RF Passive Circuits using Coupled Lines and Scalable Models Sidharth Dalmia, Sung Hwan Min.swaminathan@ee.gatech.edu Abstract Coupled line sections are critical structures in distributed RF and microwave passive circuits

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

    E-Print Network [OSTI]

    Rosen, Matthew S

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

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

    E-Print Network [OSTI]

    Nunnally, Clifton Charles

    2004-11-15

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

  20. The genotoxic contribution of wood smoke to indoor respirable suspended particles

    SciTech Connect (OSTI)

    Boone, P.M. (John B. Pierce Foundation Laboratory, New Haven, CT (USA)); Rossman, T.G. (New York Univ. Medical Center, New York (USA)); Daisey, J.M. (Lawrence Berkeley Laboratory, CA (USA))

    1989-01-01

    The effect of wood burning stoves on the genotoxicity of indoor respirable organic matter was investigated for four homes during the winter and spring of 1986. Paired samples, one collected when the stove was not used and one when wood was burned, were extracted with dichloromethane and acetone. Aliquots of the dichloromethane extracts were analyzed with and without metabolic activation using the Microscreen bioassay. The Microscreen is a rapid, sensitive bioassay which measures a broad genotoxic endpoint, {lambda}-prophage induction. Per nanogram of organic material, wood smoke proved to be a major source of indirect (observed with metabolic activation) but not direct genotoxins in homes. The increase in indirect genotoxicity for extracts from aerosol containing wood smoke is probably due to higher concentrations of polycyclic aromatic hydrocarbons in the wood smoke aerosol as well as other unidentified classes. The direct genotoxicity observed for extracts of aerosol not containing wood smoke decreased with metabolic activation. This direct genotoxicity may be related to cooking activities in the homes. The trends in genotoxicity observed per nanogram of organic material are more pronounced when expressed per m{sup 3} of air due to the higher percentage of extractable material in aerosol containing wood smoke.

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

    SciTech Connect (OSTI)

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

    2007-09-15

    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.

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

    E-Print Network [OSTI]

    Milam, Kyle Zohn

    1985-01-01

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

  3. Simulation results of an inductively-coupled rf plasma torch in two and three dimensions for producing a metal matrix composite for nuclear fuel cladding 

    E-Print Network [OSTI]

    Holik III, Eddie Frank (Trey)

    2009-05-15

    I propose to develop a new method for the synthesis of metal matrix composites (MMC) using aerosol reactants in a radio frequency (RF) plasma torch. An inductivelycoupled RF plasma torch (ICPT) may potentially be designed ...

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

    E-Print Network [OSTI]

    Qiang, J.

    2010-01-01

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

  5. 2004 URSI Meeting, 5-8 January 2004, at the University of Colorado, Boulder, Colorado, USA. Polyimide Planarization for RF-MEMS Switch on PCB

    E-Print Network [OSTI]

    De Flaviis, Franco

    Polyimide Planarization for RF-MEMS Switch on PCB Bahram Ghodsian, C. Jung, B. Cetiner and F. De Flaviis it maintains the high RF-performance of switches. The fabrication process uses polyimide to planerize

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

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  7. FIRE Physics Issues 1-3 May 2000 RF Heating Scenarios

    E-Print Network [OSTI]

    1 FIRE Physics Issues 1-3 May 2000 RF Heating Scenarios Dick Majeski, Dave Swain, Mark Carter Princeton Plasma Physics Laboratory and Oak Ridge National Laboratory Physics Issues for FIRE PPPL 1-3 May 2000 #12;2 FIRE Physics Issues 1-3 May 2000 Introduction and requirements FIRE heating and current

  8. RF Power Potential of 90 nm CMOS: Device Options, Performance, and Reliability

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    of the RF power potential of the various device options offered in a state-of-the-art 90 nm CMOS foundry and reliability. In a modern foundry process, in addition to the nominal digital devices, it is common to offer in a foundry process. Technology The technology that has been studied in this work is a foundry 90 nm CMOS

  9. A Measurement Study of Zigbee-based Indoor Localization Systems Under RF Interference

    E-Print Network [OSTI]

    Huang, Polly

    A Measurement Study of Zigbee-based Indoor Localization Systems Under RF Interference Seng 802.11) and Zigbee (IEEE 802.15.4) all operate in the 2.4x GHz fre- quency bands. The stability and availability of RSSI infor- mation for WiFi- or Zigbee-based localization systems may vary depending

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

    E-Print Network [OSTI]

    Fijalkow, Inbar

    design, which reduces the chip area and the number of components (Green #12;design) or facilitate. Concerning the RF part, designing a Green radio first consists in the improvement of efficiency. It is well front-end imperfections can participate in the design of Green radio. Some of these corrections enable

  11. High Power RF Tests on WR650 Pre-Stressed Planar Windows

    SciTech Connect (OSTI)

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

    2009-11-01

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

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

    E-Print Network [OSTI]

    Scerri, Paul

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

  13. CMOS RF front-end design for terrestrial and mobile digital television systems 

    E-Print Network [OSTI]

    Xiao, Jianhong

    2007-09-17

    of the mobile DVB-H tuner, a novel RF variable gain amplifier (RFVGA) and a low flicker noise current-mode passive mixer have been proposed. The proposed RFVGA achieves high dynamic range and robust input impedance matching performance, which is the main design...

  14. Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love

    E-Print Network [OSTI]

    Devoret, Michel H.

    .4 Tunneling Rates in the single Electron Trap . . . . . . . . . . . . . . . . . . . . . . . 49 5 CotunnellingAbstract Resolved dynamics of single electron tunneling using the RF-SET Julie Helen Love 2007 This thesis presents measurements of time resolved single electron tunneling events in a metallic thin film

  15. Use of THz Photoconductive Sources to Characterize Tunable Graphene RF Plasmonic

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    1 Use of THz Photoconductive Sources to Characterize Tunable Graphene RF Plasmonic Antennas A. Cabellos, I. Llatser, E. Alarc´on, A. Hsu and T. Palacios Abstract--Graphene, owing to its ability challenges in the characterization and demonstration of graphene antennas is finding suitable terahertz

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

    E-Print Network [OSTI]

    Cong, Jason "Jingsheng"

    Power Reduction of CMP Communication Networks via RF-Interconnects M-C. Frank Chang , Jason Cong multiprocessors scale to a greater number of processing cores, on-chip interconnection networks will ex- perience dramatic increases in both bandwidth demand and power dissipation. Fortunately, promising gains can be re

  17. Proc 12th conf. RF Power in Plasmas, Savannah, 1997 Ion-Bernstein Wave Mode Conversion

    E-Print Network [OSTI]

    Jaun, André

    Proc 12th conf. RF Power in Plasmas, Savannah, 1997 Ion-Bernstein Wave Mode Conversion in Hot-Bernstein wave can dramatically affect the power profile and partition among the species. The results obtained very different wavelengths. Where the spa- tial scale of two waves match, the power associated with one

  18. Diagnostics of ballistic electrons in a dc/rf hybrid capacitively coupled discharge

    E-Print Network [OSTI]

    Economou, Demetre J.

    Diagnostics of ballistic electrons in a dc/rf hybrid capacitively coupled discharge Lin Xu,1,a Lee the substrate electrode or the semiconduc- tor wafer. Watanabe et al.7 superimposed a high energy electron beam. Economou,2,c and Vincent M. Donnelly2,d 1 Tokyo Electron America, Austin, Texas 78741, USA 2 Department

  19. Realization and Modeling of Metamaterials Made of rf Superconducting Quantum-Interference Devices

    E-Print Network [OSTI]

    Anlage, Steven

    ,5], cloaking [6,7], transformation optics [8,9], and perfect absorption [10]. Most of the applications invoking in space (e.g., for cloaking or transformation optics) or that can be tuned and reconfigured after for digital rf receivers [25,26]. Superconducting metamaterials have been proposed to address all three

  20. On the Placement of RF Energy Harvesting Node in Wireless Networks with Secrecy Considerations

    E-Print Network [OSTI]

    Zhou, Xiangyun "Sean"

    On the Placement of RF Energy Harvesting Node in Wireless Networks with Secrecy Considerations Biao of harvesting wireless energy, it is desirable to have the EH node located close to the transmitter. However approach to reduce the energy consumption and prolong the lifetime of wireless networks. Apart from

  1. Optimization and Characterization of RF Sputtered Piezoelectric Zinc Oxide Thin Film for

    E-Print Network [OSTI]

    Tang, William C

    Oxide (ZnO) thin films had been found to have unique piezoelectric effect for the applicationsOptimization and Characterization of RF Sputtered Piezoelectric Zinc Oxide Thin Film for Transducer Applications Yu-Hsiang Hsu, John Lin, and William C. Tang* Department of Biomedical Engineering University

  2. NON-RECIPROCAL SAW DEVICES FOR RF APPLICATIONS M. Rotter, W. Ruile

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    NON-RECIPROCAL SAW DEVICES FOR RF APPLICATIONS M. Rotter, W. Ruile Siemens AG, Corporate Technology of a semiconductor heterostructure and the acoustic properties of strongly piezoelectric crystals yields promising hybrids for potential acousto electric applications. The nonlinear interaction between an intense SAW

  3. UNI\\'ERSm RF..olS'l'UAR BACHELOR OF SCIENCE IN BIOCHEMISTRY

    E-Print Network [OSTI]

    Virginia Tech

    APPPO'T.D UNI\\'ERSm RF..olS'l'UAR BACHELOR OF SCIENCE IN BIOCHEMISTRY COLLEGE OF SCIENCE GRADUATION: Scientific Reasoning and Discovery (Natural Sciences): BeRM 1014 Introduction to Biochemistry General Biochemistry Lab. Prob. Biochemistry (1)_ (4)_ (3)_ (6)_ #BCHM 4115 4116 #BCHM 4124 #12;BlOC 2013 BIOL 1105 l

  4. Performance Analysis of Ambient RF Energy Harvesting: A Stochastic Geometry Approach

    E-Print Network [OSTI]

    Privault, Nicolas

    proposed as a potential solution to provide proactive energy replenishment for wireless devices. This paper aims to analyze the performance of a battery-free wireless sensor powered by ambient RF energy signals into electricity. Therefore, it has recently emerged as an alternative method to operate low

  5. Electromechanical Modeling and Simulation of RF MEMS Switches Yong Zhu and Horacio D. Espinosa

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Electromechanical Modeling and Simulation of RF MEMS Switches Yong Zhu and Horacio D. Espinosa the electromechanical behavior of a fixed-fixed switch. However, in some practical applications, multi and discuss their electromechanical performances. The switch, bottom electrode and surrounding air were all

  6. RF Distribution System for High Power Test of the SNS Cryomodule

    SciTech Connect (OSTI)

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

    2012-01-01

    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.

  7. Aspect Ratio Dependence of Bootstrap Current and RF Current Driving Efficiency

    E-Print Network [OSTI]

    Boyer, Edmond

    . Ashidaa a National Institute of advanced Industrial Science and Technology, Tsukuba, Japan, b Nihon University, Institute of Quantum Science, Tokyo, Japan, c Nihon University, College of Industrial Technology pinch (RFP) with the low aspect ratio of A = 2.0, then significantly reduces the rf-driven current

  8. S-Band Waveguide Reconfiguration Options for the LCLS RF Gun and L0 Klystron Feeds

    SciTech Connect (OSTI)

    McIntosh, P.

    2005-01-28

    This note highlights the possible re-configuration options for the existing WR284 S-band waveguide in the klystron gallery, to enable those existing 5045 klystrons to power the RF Gun and the L0 accelerating structures for LCLS. A reconfiguration decision based on the pros and cons for each option is subsequently identified.

  9. TESLA Report 2004-02 Anti-multipactor TiN coating of RF power

    E-Print Network [OSTI]

    N layers generation on surfaces which were not protected in this way previously. Thin TiN films on ceramicTESLA Report 2004-02 1 Anti-multipactor TiN coating of RF power coupler components for TESLA performance of couplers) J. Lorkiewicz1 , The Andrzej Soltan Institute for Nuclear Studies, Pl 05-400 Otwock

  10. Localization algorithms for sensor networks using RF signal CS 252 Class Project

    E-Print Network [OSTI]

    Nguyen, Long

    Localization algorithms for sensor networks using RF signal strength CS 252 Class Project Xuan represent a future branch of computer architecture research. As Moore's law continues to drive more and more in wireless node distance estimation. Then, based on characteristics of this distance estimation, we develop

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

    E-Print Network [OSTI]

    Zhu, Feng

    2012-02-14

    A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

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

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Identification of Residual Stress State in an RF-MEMS Device l Horacio D. Espinosa, M. Fischer Dept Microelectromechanical Systems (MEMS) are among the most significant technological advances of this decade. The objective is of a few nanometers. The study of "thin films" and "ultra thin films" employed in MEMS devices is being

  13. WTJ(S^rf7?\\ Ris-R-761p*

    E-Print Network [OSTI]

    WTJ(S^rf7?\\ Risø-R-761£p*Thermonuclear Fusion September 1994 #12;ANNUAL PROGRESS _****ig*r REPORT 1993 Work in Controlled Thermonuclear Fusion Research Research Performed in The Fusion Research Unit underthe Contract ofAssociationbetween Euratom and Risø

  14. Epitaxial growth of lead zirconium titanate thin films on Ag buffered Si substrates using rf sputtering

    E-Print Network [OSTI]

    Laughlin, David E.

    Epitaxial growth of lead zirconium titanate thin films on Ag buffered Si substrates using rf 7 February 2007; accepted 25 March 2007; published online 23 April 2007 Epitaxial lead zirconium American Institute of Physics. DOI: 10.1063/1.2731515 The ferroelectric material lead zirconium titanate Pb

  15. Feedback based Sparse Recovery for Motion Tracking in RF Sensor Networks

    E-Print Network [OSTI]

    Qiu, Robert Caiming

    Feedback based Sparse Recovery for Motion Tracking in RF Sensor Networks Heping Song #1 , Tong Liu #2 , Xiaomu Luo #3 , Guoli Wang #4 # School of Information Science and Technology, Sun Yat tracking with radio tomographic networks using received signal strength (RSS) measurements has attracted

  16. Ion transport in macroscopic RF linear traps Jofre Pedregosa-Gutierrez,

    E-Print Network [OSTI]

    Boyer, Edmond

    ´er^ome, 13397 Marseille Cedex 20, France (Dated: July 18, 2014) Abstract Efficient transport of cold atomsIon transport in macroscopic RF linear traps Jofre Pedregosa-Gutierrez, Caroline Champenois, Marius information processing to frequency metrology. Different transport schemes have been developed, which allow

  17. Methods And Apparatus For Acoustic Fiber Fractionation

    DOE Patents [OSTI]

    Brodeur, Pierre (Smyrna, GA)

    1999-11-09

    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.

  18. Radiotherapy Dose Fractionation under Parameter Uncertainty

    SciTech Connect (OSTI)

    Davison, Matt; Kim, Daero; Keller, Harald

    2011-11-30

    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.

  19. Reflective Cracking Study: First-level Report on HVS Testing on Section 591RF - 45 mm MAC15TR-GOverlay

    E-Print Network [OSTI]

    Jones, David; Wu, R.; Harvey, John T

    2008-01-01

    Testing on Section 588RF — 90 mm AR4000-D Overlay (UCPRC-RR-Testing on Section 586RF — 45 mm MB15-G Overlay (UCPRC-RR-Testing on Section 591RF — 45 mm MAC15TR-G Overlay (UCPRC-

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

    E-Print Network [OSTI]

    Wurtele, Jonathan

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

  1. Waveguide Side-Wall Coupling in RF Guns Leon C.-L. Lin, S. C. Chen, J. Gonichon, S. Trotz, and J. S. Wurtele

    E-Print Network [OSTI]

    Wurtele, Jonathan

    Waveguide Side-Wall Coupling in RF Guns Leon C.-L. Lin, S. C. Chen, J. Gonichon, S. Trotz, and J. S side-wall coupling for RF guns is investigated both theoretically and experimentally. We model agreement with theory. I. INTRODUCTION Photocathode RF guns are promising high brightness elec- tron beam

  2. Fractional Quantum Hall States in Graphene

    E-Print Network [OSTI]

    Ahmed Jellal; Bellati Malika

    2011-04-27

    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 \

  3. Excursions of diffusion processes and continued fractions

    E-Print Network [OSTI]

    Alain Comtet; Yves Tourigny

    2010-02-11

    It is well-known that the excursions of a one-dimensional diffusion process can be studied by considering a certain Riccati equation associated with the process. We show that, in many cases of interest, the Riccati equation can be solved in terms of an infinite continued fraction. We examine the probabilistic significance of the expansion. To illustrate our results, we discuss some examples of diffusions in deterministic and in random environments.

  4. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Emil J. Martinec

    2015-05-20

    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  5. Tunable fractional-order Fourier transformer

    SciTech Connect (OSTI)

    Malyutin, A A [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2006-01-31

    A fractional two-dimensional Fourier transformer whose orders are tuned by means of optical quadrupoles is described. It is shown that in the optical scheme considered, the Fourier-transform order a element of [0,1] in one of the mutually orthogonal planes corresponds to the transform order (2-a) in another plane, i.e., to inversion and inverse Fourier transform of the order a. (laser modes and beams)

  6. The Fractional London Equation and The Fractional Pippard Model For Superconductors

    E-Print Network [OSTI]

    José Weberszpil

    2012-07-23

    With the discovery of new superconductors there was a running to find the justifications for the new properties found in these materials. In order to describe these new effects some theories were adapted and some others have been tried. In this work we present an application of the fractional calculus to study the superconductor in the context of London theory. Here we investigated the linear London equation modified by fractional derivatives for non-differentiable functions, instead of integer ones, in a coarse grained scenario. We apply the fractional approach based in the modified Riemann-Liouville sense to improve the model in order to include possible non-local interactions and the media. It is argued that the e ects of non-locality and long memory, intrinsic to the formalism of the fractional calculus, are relevant to achieving a satisfactory phenomenological description. In order to compare the present results with the usual London theory, we calculated the magnetic field distribution for a mesoscopic superconductor system. Also, a fractional Pippard-like model is proposed to take into account the non-locality beside effects of interactions and the media. We propose that parameter alfa of fractionality can be used to create an alternative way to characterize superconductors.

  7. The First Calculation of Fractional Jets

    E-Print Network [OSTI]

    Daniele Bertolini; Jesse Thaler; Jonathan R. Walsh

    2015-05-14

    In collider physics, jet algorithms are a ubiquitous tool for clustering particles into discrete jet objects. Event shapes offer an alternative way to characterize jets, and one can define a jet multiplicity event shape, which can take on fractional values, using the framework of "jets without jets". In this paper, we perform the first analytic studies of fractional jet multiplicity $\\tilde{N}_{\\rm jet}$ in the context of $e^+e^-$ collisions. We use fixed-order QCD to understand the $\\tilde{N}_{\\rm jet}$ cross section at order $\\alpha_s^2$, and we introduce a candidate factorization theorem to capture certain higher-order effects. The resulting distributions have a hybrid jet algorithm/event shape behavior which agrees with parton shower Monte Carlo generators. The $\\tilde{N}_{\\rm jet}$ observable does not satisfy ordinary soft-collinear factorization, and the $\\tilde{N}_{\\rm jet}$ cross section exhibits a number of unique features, including the absence of collinear logarithms and the presence of soft logarithms that are purely non-global. Additionally, we find novel divergences connected to the energy sharing between emissions, which are reminiscent of rapidity divergences encountered in other applications. Given these interesting properties of fractional jet multiplicity, we advocate for future measurements and calculations of $\\tilde{N}_{\\rm jet}$ at hadron colliders like the LHC.

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

    SciTech Connect (OSTI)

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

    2010-12-07

    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

  9. Final Report for "Design calculations for high-space-charge beam-to-RF conversion".

    SciTech Connect (OSTI)

    David N Smithe

    2008-10-17

    Accelerator facility upgrades, new accelerator applications, and future design efforts are leading to novel klystron and IOT device concepts, including multiple beam, high-order mode operation, and new geometry configurations of old concepts. At the same time, a new simulation capability, based upon finite-difference “cut-cell” boundaries, has emerged and is transforming the existing modeling and design capability with unparalleled realism, greater flexibility, and improved accuracy. This same new technology can also be brought to bear on a difficult-to-study aspect of the energy recovery linac (ERL), namely the accurate modeling of the exit beam, and design of the beam dump for optimum energy efficiency. We have developed new capability for design calculations and modeling of a broad class of devices which convert bunched beam kinetic energy to RF energy, including RF sources, as for example, klystrons, gyro-klystrons, IOT's, TWT’s, and other devices in which space-charge effects are important. Recent advances in geometry representation now permits very accurate representation of the curved metallic surfaces common to RF sources, resulting in unprecedented simulation accuracy. In the Phase I work, we evaluated and demonstrated the capabilities of the new geometry representation technology as applied to modeling and design of output cavity components of klystron, IOT's, and energy recovery srf cavities. We identified and prioritized which aspects of the design study process to pursue and improve in Phase II. The development and use of the new accurate geometry modeling technology on RF sources for DOE accelerators will help spark a new generational modeling and design capability, free from many of the constraints and inaccuracy associated with the previous generation of “stair-step” geometry modeling tools. This new capability is ultimately expected to impact all fields with high power RF sources, including DOE fusion research, communications, radar and other defense applications.

  10. Predictions of VRF on a Langmuir Probe under the RF Heating Spiral on the Divertor Floor on NSTX-U

    SciTech Connect (OSTI)

    Hosea, J C [PPPL; Perkins, R J [PPPL; Jaworski, M A [PPPL; Kramer, G J [PPPL; Ahn, J-W [ORNL

    2014-07-01

    RF heating deposition spirals are observed on the divertor plates on NSTX as shown in for a NB plus RF heating case. It has been shown that the RF spiral is tracked quite well by the spiral mapping of the strike points on the divertor plate of magnetic field lines passing in front of the high harmonic fast wave (HHFW) antenna on NSTX. Indeed, both current instrumented tiles and Langmuir probes respond to the spiral when it is positioned over them. In particular, a positive increment in tile current (collection of electrons) is obtained when the spiral is over the tile. This current can be due to RF rectification and/or RF heating of the scrape off layer (SOL) plasma along the magnetic field lines passing in front of the the HHFW antenna. It is important to determine quantitatively the relative contributions of these processes. Here we explore the properties of the characteristics of probes on the lower divertor plate to determine the likelyhood that the primary cause of the RF heat deposition is RF rectification.

  11. Production of stable, non-thermal atmospheric pressure rf capacitive plasmas using gases other than helium or neon

    DOE Patents [OSTI]

    Park, Jaeyoung; Henins, Ivars

    2005-06-21

    The present invention enables the production of stable, steady state, non-thermal atmospheric pressure rf capacitive .alpha.-mode plasmas using gases other than helium and neon. In particular, the current invention generates and maintains stable, steady-state, non-thermal atmospheric pressure rf .alpha.-mode plasmas using pure argon or argon with reactive gas mixtures, pure oxygen or air. By replacing rare and expensive helium with more readily available gases, this invention makes it more economical to use atmospheric pressure rf .alpha.-mode plasmas for various materials processing applications.

  12. An rf-carpet electrospray ion source to provide isobaric mass calibrants for trans-uranium elements

    E-Print Network [OSTI]

    S. Naimi; S. Nakamura; Y. Ito; H. Mita; K. Okada; A. Ozawa; P. Schury; T. Sonoda; A. Takamine; M. Wada; H. Wollnik

    2012-12-16

    For trans-uranium elements, stable atomic isobars do not exist. In order to provide isobaric reference ions for the mass measurement of trans-uranium elements, an electrospray ion source (ESI) was combined with an rf-carpet to collect molecular ions efficiently. The rf-carpet allows for simplification of the pumping system to transport ions from the ESI to a precision mass analyzer. Molecular ions appropriate for isobaric references of trans-uranium elements were extracted from the rf-carpet and analyzed by a multi-reflection time-of-flight mass spectrograph (MRTOF-MS) with a resolving power of $\\rm{R_m} \\gtrsim100,000$.

  13. Polyfunctional catalyst for processiing benzene fractions

    SciTech Connect (OSTI)

    G. Byakov; B.D. Zubitskii; B.G. Tryasunov; I.Ya. Petrov

    2009-05-15

    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.

  14. Motility fractionation of bacteria by centrifugation

    E-Print Network [OSTI]

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

    2013-10-10

    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.

  15. Hydrolysis and fractionation of lignocellulosic biomass

    DOE Patents [OSTI]

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

    2000-01-01

    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.

  16. Fractionation Development Center FDC | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View New PagesSustainable Urban TransportFortistar LLC Jump to:EnergyMontana:Fox,Fractionation

  17. E-model for Transportation Problem of Linear Stochastic Fractional ...

    E-Print Network [OSTI]

    Dr.V.Charles

    2007-03-07

    Abstract: This paper deals with the so-called transportation problem of linear stochastic fractional programming, and ... sophisticated analysis. Stochastic ... circuit board of multi-objective LSFP, algorithm to identify redundant fractional objective ...

  18. Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui

    E-Print Network [OSTI]

    Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui Sitindra S studied the controls on the fractionation of hydrogen isotopes during lipid biosynthesis by Haloarcula marismortui, a halophilic archaea, in pure culture experiments by varying organic substrate, the hydrogen

  19. Assessing the impacts of fractionation on pointing-intensive spacecraft

    E-Print Network [OSTI]

    O'Neill, Michael Gregory

    2010-01-01

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

  20. Numerical Chaos in a Fractional Order Logistic Map

    E-Print Network [OSTI]

    Joakim Munkhammar

    2010-11-10

    In this paper we investigate a fractional order logistic map and its discrete time dynamics. We show some basic properties of the fractional logistic map and numerically study its period-doubling route to chaos.

  1. Non-local fractional model of rate independent plasticity

    E-Print Network [OSTI]

    Wojciech Sumelka

    2013-09-14

    In the paper the generalisation of classical rate independent plasticity using fractional calculus is presented. This new formulation is non-local due to properties of applied fractional differential operator during definition of kinematics. In the description small fractional strains assumption is hold together with additive decomposition of total fractional strains into elastic and plastic parts. Classical local rate independent plasticity is recovered as a special case.

  2. Soliton Solutions of Fractional order KdV-Burger's Equation

    E-Print Network [OSTI]

    Muhammad Younis

    2013-08-31

    In this article, the new exact travelling wave solutions of the time-and space-fractional KdV-Burgers equation has been found. For this the fractional complex transformation have been implemented to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations, in the sense of the Jumarie's modified Riemann-Liouville derivative. Afterwards, the improved (G'/G)-expansion method can be implemented to celebrate the soliton solutions of KdV-Burger's equation of fractional order.

  3. An Epiperimetric Inequality Approach to the Thin and Fractional ...

    E-Print Network [OSTI]

    Arshak Petrosyan(joint with Nicola Garofalo, Camelia Pop, and Mariana Smit Vega Garcia)

    2015-07-28

    Jun 15, 2015 ... An Epiperimetric Inequality. Approach to the Thin and. Fractional Obstacle Problems. Geometric Analysis. Free Boundary Problems. & Measure ...

  4. Process for stabilization of coal liquid fractions

    DOE Patents [OSTI]

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

    1987-01-01

    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.

  5. Field-flow fractionation of chromosomes

    SciTech Connect (OSTI)

    Giddings, J.C.

    1991-09-01

    The work done on this project is divided into two principal areas. The first involves the application of sedimentation/steric FFF to metaphase chromosomes in an attempt to fractionate the chromosomes according to their size. The preparation of chromosomes from a number of organisms was attempted; procedures were finally worked out in collaboration with Los Alamos National Laboratory for the preparation of metaphase chromosomes from Chinese hamster cells. After extensive experimental work was done to identify suitable operating conditions, the partial fractionation of the Chinese hamster chromosomes was achieved. In the second component of the project, flow FFF was applied to the separation of DNA fragments. Figures are provided that show considerable success in the separation of plasmid digests and in the separation of single from double stranded DNA under 10{sup 4} base pairs. Preliminary work was done on DNA fragments having a size greater than 10{sup 4} base pairs. This work has served to establish the inversion point for DNA.

  6. Some Applications of the Fractional Poisson Probability Distribution

    E-Print Network [OSTI]

    Nick Laskin

    2011-11-17

    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.

  7. ORIGINAL ARTICLE Metagenomic analysis of size-fractionated

    E-Print Network [OSTI]

    Stewart, Frank

    and metabolism of OMZ microorganisms vary between particle-associated and free-living size fractions. We used.6 lm) and small (0.2­1.6 lm) filter size fractions along a depth gradient in the OMZ off Chile. Despite steep vertical redox gradients, size fraction was a significantly stronger predictor of community

  8. Deviation probability bounds for fractional martingales and related remarks

    E-Print Network [OSTI]

    Saussereau, Bruno

    2012-01-01

    In this paper we prove exponential inequalities (also called Bernstein's inequality) for fractional martingales. As an immediate corollary, we will discuss weak law of large numbers for fractional martingales under divergence assumption on the $\\beta-$variation of the fractional martingale. A non trivial example of application of this convergence result is proposed.

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

    E-Print Network [OSTI]

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

    2007-03-26

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

  10. Design and Construction of a 500 KW CW, 400 MHZ Klystron To Be Used As RF Power Source For LHC/RF Component Tests

    SciTech Connect (OSTI)

    Pearson, Chris

    2003-05-05

    A 500 kW cw klystron operating at 400 MHz was developed and constructed jointly by CERN and SLAC for use as a high-power source at CERN for testing LHC/RF components such as circulators, RF absorbers and superconducting cavities with their input couplers. The design is a modification of the 353 MHz SLAC PEP-I klystron. More than 80% of the original PEP-I tube parts could thus be incorporated in the LHC test klystron which resulted in lower engineering costs as well as reduced development and construction time. The physical length between cathode plane and upper pole plate was kept unchanged so that a PEP-I tube focusing solenoid, available at CERN, could be re-used. With the aid of the klystron simulation codes JPNDISK and CONDOR, the design of the LHC tube was accomplished, which resulted in a tube with noticeably higher efficiency than its predecessor, the PEP-I klystron. The integrated cavities were redesigned using SUPERFISH and the output coupling circuit, which also required redesigning, was done with the aid of MAFIA. Details of the tube development and test results are presented.

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

    SciTech Connect (OSTI)

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

    2012-09-01

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

  12. High Thermal Conductivity Cryogenic RF Feedthroughs for Higher Order Mode Couplers

    SciTech Connect (OSTI)

    Charles Reece; Edward Daly; Thomas Elliott; H. Phillips; Joseph Ozelis; Timothy Rothgeb; Katherine Wilson; Genfa Wu

    2005-05-01

    The use of higher-order-mode (HOM) pickup probes in the presence of significant fundamental RF fields can present a thermal challenge for CW or high average power SRF cavity applications. The electric field probes on the HOM-damping couplers on the JLab ''High Gradient'' (HG) and ''Low Loss'' (LL) seven-cell cavities for the CEBAF upgrade are exposed to approximately 10% of the peak magnetic field in the cavity. To avoid significant dissipative losses, these probes must remain superconducting during operation. Typical cryogenic rf feedthroughs provide a poor thermal conduction path for the probes and provide inadequate stabilization. We have developed solutions that meet the requirements, providing a direct thermal path from the niobium probe, thorough single-crystal sapphire, to bulk copper which can be thermally anchored. Designs, electromagnetic and thermal analyses, and performance data will be presented.

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

    SciTech Connect (OSTI)

    Castilla Loeza, Alejandro; Delayen, Jean R.

    2013-12-01

    On the scheme of developing a medium energy electron-ion collider (MEIC) at Jefferson Lab, we have designed a compact superconducting rf dipole cavity at 750 MHz to crab both electron and ion bunches and increase luminosities at the interaction points (IP) of the machine. Following the design optimization and characterization of the electromagnetic properties such as peak surface fields and shunt impedance, along with field nonuniformities, multipole components content, higher order modes (HOM) and multipacting, a prototype cavity was built by Niowave Inc. The 750 MHz prototype crab cavity has been tested at 4 K and is ready for re-testing at 4 K and 2 K at Jefferson Lab. In this paper we present the detailed results of the rf tests performed on the 750 MHz crab cavity prototype.

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

    SciTech Connect (OSTI)

    Towne N.; Rose J.

    2011-09-30

    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.

  15. Characterization of a klystrode as a RF source for high-average-power accelerators

    SciTech Connect (OSTI)

    Rees, D.; Keffeler, D.; Roybal, W.; Tallerico, P.J.

    1995-05-01

    The klystrode is a relatively new type of RF source that has demonstrated dc-to-RF conversion efficiencies in excess of 70% and a control characteristic uniquely different from those for klystron amplifiers. The different control characteristic allows the klystrode to achieve this high conversion efficiency while still providing a control margin for regulation of the accelerator cavity fields. The authors present test data from a 267-MHz, 250-kW, continuous-wave (CW) klystrode amplifier and contrast this data with conventional klystron performance, emphasizing the strengths and weaknesses of the klystrode technology for accelerator applications. They present test results describing that limitation for the 250-kW, CW klystrode and extrapolate the data to other frequencies. A summary of the operating regime explains the clear advantages of the klystrode technology over the klystron technology.

  16. The effect of discharge chamber geometry on the ignition of low-pressure rf capacitive discharges

    SciTech Connect (OSTI)

    Lisovskiy, V.; Martins, S.; Landry, K.; Douai, D.; Booth, J.-P.; Cassagne, V.; Yegorenkov, V. [Laboratoire de Physique et Technologie des Plasmas, Ecole Polytechnique, Palaiseau 91128, France and Kharkov National University, Kharkov 61077 (Ukraine); Unaxis Displays Division France SAS, 5, Rue Leon Blum, Palaiseau 91120 (France); Laboratoire de Physique et Technologie des Plasmas, Ecole Polytechnique, Palaiseau 91128 (France); Unaxis Displays Division France SAS, 5, Rue Leon Blum, Palaiseau 91120 (France); Kharkov National University, Kharkov 61077 (Ukraine)

    2005-09-15

    This paper reports measured and calculated breakdown curves in several gases of rf capacitive discharges excited at 13.56 MHz in chambers of three different geometries: parallel plates surrounded by a dielectric cylinder ('symmetric parallel plate'), parallel plates surrounded by a grounded metallic cylinder ('asymmetric parallel plate'), and parallel plates inside a much larger grounded metallic chamber ('large chamber'). The breakdown curves for the symmetric chamber have a multivalued section at low pressure. For the asymmetric chamber the breakdown curves are shifted to lower pressures and rf voltages, but the multivalued feature is still present. At higher pressures the breakdown voltages are much lower than for the symmetric geometry. For the large chamber geometry the multivalued behavior is not observed. The breakdown curves were also calculated using a numerical model based on fluid equations, giving results that are in satisfactory agreement with the measurements.

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

    SciTech Connect (OSTI)

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

    2011-01-01

    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.

  18. A new approach to calculate the transport matrix in RF cavities

    SciTech Connect (OSTI)

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

    2011-03-01

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

  19. IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 55, NO. 4, APRIL 2007 1193 Frequency Tunable Microstrip Patch Antenna Using RF

    E-Print Network [OSTI]

    Akin, Tayfun

    integrated with RF microelectromechanical systems (MEMS) capacitors for tuning the resonant frequency at low dc voltages. Index Terms--Microelectromechanical system (MEMS), microstrip an- tennas, microwave, reconfigurable architectures. I. INTRODUCTION Microelectromechanical systems (MEMS) and the application

  20. Effect of varying gate-drain distance on the RF power performance of pseudomorphic high electron mobility transistors

    E-Print Network [OSTI]

    Wong, Melinda F

    2005-01-01

    AIGaAs/lnGaAs Pseudomorphic High Electron Mobility Transistors (PHEMTs) are widely used in satellite communications, military and commercial radar, cellular telephones, and other RF power applications. One key figure of ...

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

    SciTech Connect (OSTI)

    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)

    2012-11-15

    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.

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

    SciTech Connect (OSTI)

    Chevalier, N. R.; Thermeau, J.-P.; Bujard, P.; Junquera, T. [Accelerators and Cryogenic Systems (ACS), 86 rue de Paris, 91400 Orsay (France); Hermansson, L.; Kern, R. Santiago; Ruber, R. [Uppsala University, Department of Physics and Astronomy, 75120 Uppsala (Sweden)

    2014-01-29

    Uppsala University is constructing a large scale facility, called FREIA (Facility for Research Instrumentation and Accelerator Development). FREIA includes a helium liquefier and an accelerator test facility and has the capacity to test superconducting radio-frequency (RF) cavities with the same RF system and RF power level as in an accelerator. A central element of FREIA is a horizontal test cryostat connected in closed loop to a helium liquefier. This cryostat can house two fully equipped (tuners, piezo, power coupler, helium tank) superconducting cavities to perform full RF high power tests and operate at temperatures between 1.8 K and 4.2 K. The cryostat is designed to accommodate a large array of superconducting cavities and magnets, among which the European Spallation Source (ESS) type spoke and high-? elliptical cavities as well as TESLA/ILC type elliptical cavities. The present status of the project and the design of the cryostat are reported.

  3. Delay Time ConstantAnalysis for5 Optimization in RF Si/SiGeBipolar Devices

    E-Print Network [OSTI]

    Ng, Wai Tung

    Delay Time ConstantAnalysis for5 Optimization in RF Si/SiGeBipolar Devices I-S.M. Sun,H. E. Xu, R, the optimization of the SiGe epitaxial base, intrinsic collector and base doping profiles, and extrinsic collector restrict the degrees of freedom in device optimization. Furthermore, T S . M. Sun, H.E. Xu, R Tam and W. T

  4. Novel ultra-low power RF Lateral BJT on 801-CMOS compatible substrate

    E-Print Network [OSTI]

    Ng, Wai Tung

    Novel ultra-low power RF Lateral BJT on 801-CMOS compatible substrate I-Shan Michael Sun, Wai Tung) in the range between 190-300 GHz*V. The frax of the optimal device reaches 46 GHz at collector current density) for the collector region, which is incompatible with thin-film SOI-CMOS [2]. An alternative that uses thin-film SOI

  5. Initial experimental results of a machine learning-based temperature control system for an RF gun

    E-Print Network [OSTI]

    Edelen, A L; Milton, S V; Chase, B E; Crawford, D J; Eddy, N; Edstrom, D; Harms, E R; Ruan, J; Santucci, J K; Stabile, P

    2015-01-01

    Colorado State University (CSU) and Fermi National Accelerator Laboratory (Fermilab) have been developing a control system to regulate the resonant frequency of an RF electron gun. As part of this effort, we present initial test results for a benchmark temperature controller that combines a machine learning-based model and a predictive control algorithm. This is part of an on-going effort to develop adaptive, machine learning-based tools specifically to address control challenges found in particle accelerator systems.

  6. RF Power Production at the Two Beam Test Stand at CERN

    E-Print Network [OSTI]

    Syratchev, I

    2013-01-01

    The generation of short (250 ns) high peak power (135 MW) RF pulses by decelerating a high current (100 A) bunched (12 GHz) drive beam is one of the key components in the CLIC two beam acceleration scheme. Recent tests with drive beam deceleration at CERN's CTF3, using specially developed 1 m long CLIC Power Extraction and Transfer Structure (PETS) operated in a re-circulation regime have successfully demonstrated this concept. The results of these tests are presented.

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

    SciTech Connect (OSTI)

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

    2013-09-01

    A recent new analysis of field-dependent BCS rf surface impedance based on moving Cooper pairs has been presented.[1] Using this analysis coded in Mathematica TM, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the "best theoretical" performance available to potential applications with corresponding materials.

  8. Observation of Liquid Metal Actuation in Microfluidic Channels and Implementation to Tunable RF Inductors 

    E-Print Network [OSTI]

    Dogan, Yusuf

    2014-07-18

    an excitement in regard to being by me in all the processes of building my thesis. Her support on research as well as on my career has been priceless to me. vii NOMENCLATURE LM Liquid Metal EGaIn Eutectic Gallium Indium RF Radio Frequency HCI....2 Actuation of LM in Closed Loop Channel ......................................................... 26 2.2.1 Design and Fabrication ......................................................................... 26 2.2.2 Experimental Steps and Results...

  9. Improved manufacturing techniques for RF and laser hardening of missile domes. Phase I. Technical report

    SciTech Connect (OSTI)

    Pawlewicz, W.T.; Mann, I.B.; Martin, P.M.; Hays, D.D.; Graybeal, A.G.

    1982-07-01

    This report summarizes key results and accomplishements during the first year of a Manufacturing Methods and Technology project to adapt an existing Pacific Northwest Laboratory (PNL) optical coating capability developed for high-power fusion-laser applications to the case of rf and laser hardening of plastic missile domes used by the US Army (MICOM). The primary objective of the first year's work was to demonstrate rf hardening of Hellfire and Copperhead 1.06-micron missile domes by use of transparent conductive Indium Tin Oxide (ITO) coatings. The project thus involved adaptation of a coating material and process developed for flat glass components used in fusion lasers to the case of hemispherical or conical heat-sensitive plastic domes used on laser-guided missiles. Specific ITO coating property goals were an electrical sheet resistance of 10 Ohms/square, a coated-dome transmission of 80% or more at 1.06 micron wavelength (compared to 90% for a bare dome), and good adhesion. The sheet resistance goal of 10 Ohms/square was expected to result in an rf attenuation of 30 dB at the frequencies of importance.

  10. Optimizing RF gun cavity geometry within an automated injector design system

    SciTech Connect (OSTI)

    Alicia Hofler ,Pavel Evtushenko

    2011-03-28

    RF guns play an integral role in the success of several light sources around the world, and properly designed and optimized cw superconducting RF (SRF) guns can provide a path to higher average brightness. As the need for these guns grows, it is important to have automated optimization software tools that vary the geometry of the gun cavity as part of the injector design process. This will allow designers to improve existing designs for present installations, extend the utility of these guns to other applications, and develop new designs. An evolutionary algorithm (EA) based system can provide this capability because EAs can search in parallel a large parameter space (often non-linear) and in a relatively short time identify promising regions of the space for more careful consideration. The injector designer can then evaluate more cavity design parameters during the injector optimization process against the beam performance requirements of the injector. This paper will describe an extension to the APISA software that allows the cavity geometry to be modified as part of the injector optimization and provide examples of its application to existing RF and SRF gun designs.

  11. 50 MW X-BAND RF SYSTEM FOR A PHOTOINJECTOR TEST STATION AT LLNL

    SciTech Connect (OSTI)

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

    2011-03-11

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

  12. Design of a new VHF RF power amplifier system for LANSCE

    SciTech Connect (OSTI)

    Lyles, John T M

    2010-01-01

    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.

  13. Advanced concepts for high power RF generation using solid state materials

    SciTech Connect (OSTI)

    Fazio, M.V.; Erickson, G.A. [Los Alamos National Laboratory (United States)

    1999-05-01

    Traditionally, high power radio frequency and microwave energy have been generated using electron beam driven hard-vacuum tubes such as klystrons and magnetrons. High-power solid-state sources of RF have not been available. It is well known that a non-linear, dispersive system can convert a pulse into an array of solitons. Although this effect has been exploited in the optical field, using non-linear optical materials, little work has been done in the field of high voltage electronics. It is the goal of this work, which is just beginning, to develop sources of RF in the few hundreds of megahertz to gigahertz range with power levels in the hundreds of megawatts to the gigawatt level. To generate solitons a high voltage pulse is fed onto a transmission line that is periodically loaded with a non-linear ceramic dielectric in the paraelectric phase. The combination of the non-linearity and dispersion causes the pulse to break up into an array of solitons. A soliton-based system has several components: the solid state, high voltage, high current switch to provide the initial high voltage pulse; a shock line to decrease the rise time of the initial pulse to less than a few nanoseconds; and the soliton generating transmission line where the high power RF is generated when driven by the fast rising pulse from the shock line. The approach and progress to date will be described. {copyright} {ital 1999 American Institute of Physics.}

  14. Gallium arsenide digital integrated circuits for controlling SLAC CW-RF systems

    SciTech Connect (OSTI)

    Ronan, M.T.; Lee, K.L.; Corredoura, P.; Judkins, J.G.

    1988-10-01

    In order to fill the PEP and SPEAR storage rings with beams from the SLC linac and damping rings, precise control of the linac subharmonic buncher and the damping ring RF is required. Recently several companies have developed resettable GaAs master/slave D-type flip-flops which are capable of operating at frequencies of 3 GHz and higher. Using these digital devices as frequency dividers, one can phase shift the SLAC CW-RF systems to optimize the timing for filling the storage rings. We have evaluated the performance of integrated circuits from two vendors for our particular application. Using microstrip circuit techniques, we have built and operated in the accelerator several chassis to synchronize a reset signal from the storage rings to the SLAC 2.856 GHz RF and to phase shift divide-by-four and divide-by-sixteen frequency dividers to the nearest 350 psec bucket required for filling. 4 refs., 4 figs., 2 tabs.

  15. Power Dependence of the RF Surface Resistance of MgB2 Superconductor.

    SciTech Connect (OSTI)

    Tajima, T.; Findikoglu, A. T.; Jason, A. J.; Krawczyk, F. L.; Mueller, F. M.; Shapiro, A. H.; Geng, R. L.; Padamsee, Hasan,; Romanenko, A.; Moeckly, B. H.

    2005-01-01

    Magnesium diboride (MgB{sub 2}) is a superconducting material that has a transition temperature (T{sub c}) of {approx}40 K, which is {approx}30 K higher than niobium (Nb) that has been used for most superconducting RF cavities in the past decades. Last year, it was demonstrated that the RF surface resistance of MgB{sub 2} can be lower than Nb at 4 K. One of the problems with other high-T{sub c} materials such as YBCO was its rapid increase in RF surface resistance with higher surface magnetic fields. Recently, we have shown that MgB2 shows little increase in the surface resistance up to {approx}120 Oe, equivalent of an accelerating field of {approx}3 MV/m. The highest field tested was limited by available power. This result is encouraging and has made us consider fabrication of a cavity coated with MgB{sub 2} and test it. Also, there is a potential that this material has a higher critical magnetic field that enables the cavity to run at a higher gradient than Nb cavities in addition to the possibility of operation at higher temperatures.

  16. Dark photons as fractional cosmic neutrino masquerader

    SciTech Connect (OSTI)

    Ng, Kin-Wang; Tu, Huitzu; Yuan, Tzu-Chiang E-mail: huitzu@phys.sinica.edu.tw

    2014-09-01

    Recently, Weinberg proposed a Higgs portal model with a spontaneously broken global U(1) symmetry in which Goldstone bosons may be masquerading as fractional cosmic neutrinos. We extend the model by gauging the U(1) symmetry. This gives rise to the so-called dark photon and dark Higgs. The dark photons can constitute about 0.912 (0.167) to the effective number of light neutrino species if they decouple from the thermal bath before the pions become non-relativistic and after (before) the QCD transition. Restriction on the parameter space of the portal coupling and the dark Higgs mass is obtained from the freeze-out condition of the dark photons. Combining with the collider data constraints on the invisible width of the standard model Higgs requires the dark Higgs mass to be less than a few GeV.

  17. Anomalous Topological Pumps and Fractional Josephson Effects

    E-Print Network [OSTI]

    Fan Zhang; C. L. Kane

    2013-10-20

    We discover novel topological pumps in the Josephson effects for superconductors. The phase difference, which is odd under the chiral symmetry defined by the product of time-reversal and particle-hole symmetries, acts as an anomalous adiabatic parameter. These pumping cycles are different from those in the "periodic table", and are characterized by $Z\\times Z$ or $Z_2\\times Z_2$ strong invariants. We determine the general classifications in class AIII, and those in class DIII with a single anomalous parameter. For the $Z_2\\times Z_2$ topological pump in class DIII, one $Z_2$ invariant describes the coincidence of fermion parity and spin pumps whereas the other one reflects the non-Abelian statistics of Majorana Kramers pairs, leading to three distinct fractional Josephson effects.

  18. Release fractions for Rocky Flats specific accidents

    SciTech Connect (OSTI)

    Weiss, R.C.

    1992-09-01

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

  19. Partial fractioning reduction of perturbative amplitudes

    E-Print Network [OSTI]

    Srednyak, Stanislav

    2011-01-01

    A new method is presented for the simplification of loop integrals in one particle irreducible diagrams with large numbers of external lines, based on the partial fractioning of products of propagators. Whenever a loop diagram in $d$ dimensions has $d+1$ or more lines that carry the same linear combination of loop momenta, its integral can be reexpressed as a linear combination of integrals with no more than $d+1$ denominators for each such set of lines, of which $d$ are linear in the loop momenta and only one quadratic. In multiloop diagrams, the total number of linear denominators can be reduced further. In integrals with numerator momenta there may also be up to $d+1$ linear factors in the numerator.

  20. Partial fractioning reduction of perturbative amplitudes

    E-Print Network [OSTI]

    Stanislav Srednyak

    2011-12-23

    A new method is presented for the simplification of loop integrals in one particle irreducible diagrams with large numbers of external lines, based on the partial fractioning of products of propagators. Whenever a loop diagram in $d$ dimensions has $d+1$ or more lines that carry the same linear combination of loop momenta, its integral can be reexpressed as a linear combination of integrals with no more than $d+1$ denominators for each such set of lines, of which $d$ are linear in the loop momenta and only one quadratic. In multiloop diagrams, the total number of linear denominators can be reduced further. In integrals with numerator momenta there may also be up to $d+1$ linear factors in the numerator.