Test measurements on the RF charge breeder device BRIC

International Nuclear Information System (INIS)

Variale, Vincenzo; Boggia, Antonio; Clauser, Tarcisio; Raino, Antonio; Valentino, Vincenzo; Verrone, Grazia; Bak, Petr; Kustenzov, Gennady; Skarbo, Boris; Tiunov, Michael

2004-01-01

The 'charge state breeder' BRIC (BReeding Ion Charge) is based on an EBIS source and it is designed to accept Radioactive Ion Beam (RIB) with charge state +1, in a slow injection mode, to increase their charge state up to +n. BRIC has been developed at the INFN section of Bari (Italy) during these last 3 years with very limited funds. Now, it has been assembled at the LNL (Italy) where are in progress the first tests as stand alone source and where, in the future, with some implementation, it will be tested as charge breeder at ISOL/TS facility of that laboratory. BRIC could be considered as a solution for the charge state breeder of the SPES project under study also at the LNL. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion drift chamber, of a radio frequency (RF) - quadrupole aiming to filter the unwanted masses and then making a more efficient containment of the wanted ions. In this paper, the first ion charge state measurements and analysis and the effect of the RF field applied on the ion chamber will be reported and discussed. The first RF test measurements seem confirm, as foreseen by simulation results carried out previously, that a selective containment can be obtained. However, most accurate measurements needed to study with more details the effect. For this reason, few implementations of the system are in order to improve the accuracy of the measurements. The proposed modifications of the BRIC device, then, will be also presented and shortly discussed

Poisson simulation for high voltage terminal of test stand for 1MV electrostatic accelerator

Energy Technology Data Exchange (ETDEWEB)

Park, Sae-Hoon; Kim, Jeong-Tae; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Yu-Seok [Dongguk Univ.., Gyeongju (Korea, Republic of)

2014-10-15

KOMAC provide ion beam to user which energy range need to expand to MeV range and develop 1 MV electrostatic accelerator. The specifications of the electrostatic accelerator are 1MV acceleration voltage, 10 mA peak current and variable gas ion. We are developing test stand before set up 1 MV electrostatic accelerator. The test stand voltage is 300 kV and operating time is 8 hours. The test stand is consist of 300 kV high voltage terminal, DC-AC-DC inverter, power supply device inside terminal, 200MHz RF power, 5 kV extraction power supply, 300 kV accelerating tube and vacuum system.. The beam measurement system and beam dump will be installed next to accelerating tube. Poisson code simulation results of the high voltage terminal are presented in this paper. Poisson code has been used to calculate the electric field for high voltage terminal. The results of simulation were verified with reasonable results. The poisson code structure could be apply to the high voltage terminal of the test stand.

Poisson simulation for high voltage terminal of test stand for 1MV electrostatic accelerator

International Nuclear Information System (INIS)

Park, Sae-Hoon; Kim, Jeong-Tae; Kwon, Hyeok-Jung; Cho, Yong-Sub; Kim, Yu-Seok

2014-01-01

KOMAC provide ion beam to user which energy range need to expand to MeV range and develop 1 MV electrostatic accelerator. The specifications of the electrostatic accelerator are 1MV acceleration voltage, 10 mA peak current and variable gas ion. We are developing test stand before set up 1 MV electrostatic accelerator. The test stand voltage is 300 kV and operating time is 8 hours. The test stand is consist of 300 kV high voltage terminal, DC-AC-DC inverter, power supply device inside terminal, 200MHz RF power, 5 kV extraction power supply, 300 kV accelerating tube and vacuum system.. The beam measurement system and beam dump will be installed next to accelerating tube. Poisson code simulation results of the high voltage terminal are presented in this paper. Poisson code has been used to calculate the electric field for high voltage terminal. The results of simulation were verified with reasonable results. The poisson code structure could be apply to the high voltage terminal of the test stand

High power rf component testing for the NLC

International Nuclear Information System (INIS)

Vlieks, A.E.; Fowkes, W.R.; Loewen, R.J.; Tantawi, S.G.

1998-09-01

In the Next Linear Collider (NLC), the high power rf components must be capable of handling peak rf power levels in excess of 600 MW. In the current view of the NLC, even the rectangular waveguide components must transmit at least 300 MW rf power. At this power level, peak rf fields can greatly exceed 100 MV/m. The authors present recent results of high power tests performed at the Accelerator Structure Test Area (ASTA) at SLAC. These tests are designed to investigate the rf breakdown limits of several new components potentially useful for the NLC. In particular, the authors tested a new TE 01 --TE 10 circular to rectangular wrap-around mode converter, a modified (internal fin) Magic Tee hybrid, and an upgraded flower petal mode converter

Adaptive compensation of Lorentz force detuning in superconducting RF cavities

Energy Technology Data Exchange (ETDEWEB)

Pischalnikov, Yuriy [Fermilab; Schappert, Warren [Fermilab

2011-11-01

The Lorentz force can dynamically detune pulsed Superconducting RF cavities and considerable additional RF power can be required to maintain the accelerating gradient if no effort is made to compensate. Fermilab has developed an adaptive compensation system for cavities in the Horizontal Test Stand, in the SRF Accelerator Test Facility, and for the proposed Project X.

Real-time positioning in logging: Effects of forest stand characteristics, topography, and line-of-sight obstructions on GNSS-RF transponder accuracy and radio signal propagation.

Directory of Open Access Journals (Sweden)

Eloise G Zimbelman

Full Text Available Real-time positioning on mobile devices using global navigation satellite system (GNSS technology paired with radio frequency (RF transmission (GNSS-RF may help to improve safety on logging operations by increasing situational awareness. However, GNSS positional accuracy for ground workers in motion may be reduced by multipath error, satellite signal obstruction, or other factors. Radio propagation of GNSS locations may also be impacted due to line-of-sight (LOS obstruction in remote, forested areas. The objective of this study was to characterize the effects of forest stand characteristics, topography, and other LOS obstructions on the GNSS accuracy and radio signal propagation quality of multiple Raveon Atlas PT GNSS-RF transponders functioning as a network in a range of forest conditions. Because most previous research with GNSS in forestry has focused on stationary units, we chose to analyze units in motion by evaluating the time-to-signal accuracy of geofence crossings in 21 randomly-selected stands on the University of Idaho Experimental Forest. Specifically, we studied the effects of forest stand characteristics, topography, and LOS obstructions on (1 the odds of missed GNSS-RF signals, (2 the root mean squared error (RMSE of Atlas PTs, and (3 the time-to-signal accuracy of safety geofence crossings in forested environments. Mixed-effects models used to analyze the data showed that stand characteristics, topography, and obstructions in the LOS affected the odds of missed radio signals while stand variables alone affected RMSE. Both stand characteristics and topography affected the accuracy of geofence alerts.

Real-time positioning in logging: Effects of forest stand characteristics, topography, and line-of-sight obstructions on GNSS-RF transponder accuracy and radio signal propagation.

Science.gov (United States)

Zimbelman, Eloise G; Keefe, Robert F

2018-01-01

Real-time positioning on mobile devices using global navigation satellite system (GNSS) technology paired with radio frequency (RF) transmission (GNSS-RF) may help to improve safety on logging operations by increasing situational awareness. However, GNSS positional accuracy for ground workers in motion may be reduced by multipath error, satellite signal obstruction, or other factors. Radio propagation of GNSS locations may also be impacted due to line-of-sight (LOS) obstruction in remote, forested areas. The objective of this study was to characterize the effects of forest stand characteristics, topography, and other LOS obstructions on the GNSS accuracy and radio signal propagation quality of multiple Raveon Atlas PT GNSS-RF transponders functioning as a network in a range of forest conditions. Because most previous research with GNSS in forestry has focused on stationary units, we chose to analyze units in motion by evaluating the time-to-signal accuracy of geofence crossings in 21 randomly-selected stands on the University of Idaho Experimental Forest. Specifically, we studied the effects of forest stand characteristics, topography, and LOS obstructions on (1) the odds of missed GNSS-RF signals, (2) the root mean squared error (RMSE) of Atlas PTs, and (3) the time-to-signal accuracy of safety geofence crossings in forested environments. Mixed-effects models used to analyze the data showed that stand characteristics, topography, and obstructions in the LOS affected the odds of missed radio signals while stand variables alone affected RMSE. Both stand characteristics and topography affected the accuracy of geofence alerts.

DESIGN OF A DC/RF PHOTOELECTRON GUN

International Nuclear Information System (INIS)

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

2003-01-01

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

Automotive RF immunity test set-up analysis

NARCIS (Netherlands)

Coenen, M.J.; Pues, H.; Bousquet, T.; Gillon, R.; Gielen, G.; Baric, A.

2011-01-01

Though the automotive RF emission and RF immunity requirements are highly justifiable, the application of those requirements in an non-intended manner leads to false conclusions and unnecessary redesigns for the electronics involved. When the test results become too dependent upon the test set-up

RF Breakdown in Normal Conducting Single-cell Structures

CERN Document Server

Dolgashev, Valery A; Higo, Toshiyasu; Nantista, Christopher D; Tantawi, Sami G

2005-01-01

Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape and material. Experimental and theoretical study of the effects of these parameters on the breakdown limit in full scale structures is difficult and costly. We use 11.4 GHz single-cell traveling wave and standing wave accelerating structures for experiments and modeling of rf breakdown behavior. These test structures are designed so that the electromagnetic fields in one cell mimic the fields in prototype multicell structures for the X-band linear collider. Fields elsewhere in the test structures are significantly lower than that of the single cell. The setup uses matched mode converters that launch the circular TM01 mode into short test structures. The test structures are connected to the mode launchers with vacuum rf flanges. This setup allows economic testing of different cell geometries, cell materials an...

Oak Ridge rf Test Facility

International Nuclear Information System (INIS)

Gardner, W.L.; Hoffman, D.J.; McCurdy, H.C.; McManamy, T.J.; Moeller, J.A.; Ryan, P.M.

1985-01-01

The rf Test Facility (RFTF) of Oak Ridge National Laboratory (ORNL) provides a national facility for the testing and evaluation of steady-state, high-power (approx.1.0-MW) ion cyclotron resonance heating (ICRH) systems and components. The facility consists of a vacuum vessel and two fully tested superconducting development magnets from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program. These are arranged as a simple mirror with a mirror ratio of 4.8. The axial centerline distance between magnet throat centers is 112 cm. The vacuum vessel cavity has a large port (74 by 163 cm) and a test volume adequate for testing prototypic launchers for Doublet III-D (DIII-D), Tore Supra, and the Tokamak Fusion Test Reactor (TFTR). Attached to the internal vessel walls are water-cooled panels for removing the injected rf power. The magnets are capable of generating a steady-state field of approx.3 T on axis in the magnet throats. Steady-state plasmas are generated in the facility by cyclotron resonance breakdown using a dedicated 200-kW, 28-GHz gyrotron. Available rf sources cover a frequency range of 2 to 200 MHz at 1.5 kW and 3 to 18 MHz at 200 kW, with several sources at intermediate parameters. Available in July 1986 will be a >1.0-MW, cw source spanning 40 to 80 MHz. 5 figs

Beam test with the HIMAC RF control system

International Nuclear Information System (INIS)

Kanazawa, M.; Sato, K.; Itano, A.

1992-01-01

RF system of the HIMAC synchrotron has been developed and tested in the factory. With the high power system, we could sweep the acceleration frequency from 1MHz to 8MHz with the acceleration voltage of 6KV. The performance of the RF control system has been confirmed with a developed simulator of the synchrotron oscillation. Following these two tests in the factory, we had a beam test of the RF control system at TARN-II in INS (Institute for Nuclear Study, University of Tokyo). This paper describes the beam test and its results. (author)

RF Processing of the Couplers for the SNS Superconducting Cavities

International Nuclear Information System (INIS)

Y.Kang; I.E. Campisi; D. Stout; A. Vassioutchenko; M. Stirbet; M. Drury; T. Powers

2005-01-01

All eighty-one fundamental power couplers for the 805 MHz superconducting cavities of the SNS linac have been RF conditioned and installed in the cryomodules successfully. The couplers were RF processed at JLAB or at the SNS in ORNL: more than forty couplers have been RF conditioned in the SNS RF Test Facility (RFTF) after the first forty couplers were conditioned at JLAB. The couplers were conditioned up to 650 kW forward power at 8% duty cycle in traveling and standing waves. They were installed on the cavities in the cryomodules and then assembled with the airside waveguide transitions. The couplers have been high power RF tested with satisfactory accelerating field gradients in the cooled cavities

RF Breakdown in Normal Conducting Single-Cell Structures

International Nuclear Information System (INIS)

Dolgashev, V.A.; Nantista, C.D.; Tantawi, S.G.; Higashi, Y.; Higo, T.

2006-01-01

Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdown. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape and material. Experimental and theoretical study of the effects of these parameters on the breakdown limit in full scale structures is difficult and costly. We use 11.4 GHz single-cell traveling wave and standing wave accelerating structures for experiments and modeling of rf breakdown behavior. These test structures are designed so that the electromagnetic fields in one cell mimic the fields in prototype multicell structures for the X-band linear collider. Fields elsewhere in the test structures are significantly lower than that of the single cell. The setup uses matched mode converters that launch the circular TM 01 mode into short test structures. The test structures are connected to the mode launchers with vacuum rf flanges. This setup allows economic testing of different cell geometries, cell materials and preparation techniques with short turn-around time. Simple 2D geometry of the test structures simplifies modeling of the breakdown currents and their thermal effects

High Power RF Test Facility at the SNS

CERN Document Server

Kang, Yoon W; Campisi, Isidoro E; Champion, Mark; Crofford, Mark; Davis, Kirk; Drury, Michael A; Fuja, Ray E; Gurd, Pamela; Kasemir, Kay-Uwe; McCarthy, Michael P; Powers, Tom; Shajedul Hasan, S M; Stirbet, Mircea; Stout, Daniel; Tang, Johnny Y; Vassioutchenko, Alexandre V; Wezensky, Mark

2005-01-01

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) cavitites 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 conducti...

Multi-Purpose Test Stand

Data.gov (United States)

Federal Laboratory Consortium — The Multi-Purpose Test Stand is used for a wide variety of tests. The Stand is designed to be rotated through a range of fixed yaw positions to allow engines to be...

The Stimulus test stand

International Nuclear Information System (INIS)

Christofek, L.; Rapidis, P.; Reinhard, A.; Fermilab

2005-01-01

The Stimulus Test Stand was originally constructed and assembled for testing the SVX2 ASIC readout and then upgraded for SVX3 ASIC prototyping and testing. We have modified this system for SVX4 ASIC [1] prototype testing. We described the individual components below. Additional details for other hardware for SVX4 testing can be found in reference [2]. We provide a description of the Stimulus Test Stand used for prototype testing of the SVX4 chip

Planter unit test stand

Science.gov (United States)

A planter test stand was developed to evaluate individual row-crop metering units in early 2013. This test stand provided the ability to quantify actual seed metering in terms of population, seed spacing, skips, and multiples over a range of meter RPMs and vacuum pressures. Preliminary data has been...

A 12 GHz RF Power Source for the CLIC Study

Energy Technology Data Exchange (ETDEWEB)

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.

A 12 GHZ RF Power source for the CLIC study

CERN Document Server

Peauger, F; Curt, S; Doebert, S; McMonagle, G; Rossat, G; Schirm, KM; Syratchev, I; Timeo, L; Kuzikhov, S; Vikharev, AA; Haase, A; Sprehn, D; Jensen, A; Jongewaard, EN; Nantista, CD; Vlieks, A

2010-01-01

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.

RF pulse compression in the NLC test accelerator at SLAC

International Nuclear Information System (INIS)

Lavine, T.L.

1995-01-01

At the Stanford Linear Accelerator Center (SLAC), the authors are designing a Next Linear Collider (NLC) with linacs powered by X-band klystrons with rf pulse compression. The design of the linac rf system is based on X-band prototypes which have been tested at high power, and on a systems-integration test - the Next Linear Collider Test Accelerator (NLCTA) - which is currently under construction at SLAC. This paper discusses some of the systems implications of rf pulse compression, and the use of pulse compression in the NLCTA, both for peak power multiplication and for controlling, by rf phase modulation, intra-pulse variations in the linac beam energy

Automotive RF immunity test set-up analysis : why test results can't compare

NARCIS (Netherlands)

Coenen, Mart; Pues, H.; Bousquet, T.

2011-01-01

Though the automotive RF emission and RF immunity requirements are highly justifiable, the application of those requirements in an non-intended manner leads to false conclusions and unnecessary redesigns for the electronics involved. When the test results become too dependent upon the test set-up

Low Level RF System for Jefferson Lab Cryomodule Test Facility

International Nuclear Information System (INIS)

Tomasz Plawski; Trent Allison; Jean Delayen; J. Hovater; Thomas Powers

2003-01-01

The Jefferson Lab Cryomodule Test Facility (CMTF) has been upgraded to test and commission SNS and CEBAF Energy Upgrade cryomodules. Part of the upgrade was to modernize the superconducting cavity instrumentation and control. We have designed a VXI based RF control system exclusively for the production testing of superconducting cavities. The RF system can be configured to work either in Phase Locked Loop (PLL) or Self Excited Loop (SEL) mode. It can be used to drive either SNS 805 MHz or CEBAF Energy Upgrade 1497 MHz superconducting cavities and can be operated in pulsed or continuous wave (CW) mode. The base design consists of RF-analog and digital sections. The RF-analog section includes a Voltage Control Oscillator (VCO), phase detector, IandQ modulator and ''low phase shift'' limiter. The digital section controls the analog section and includes ADC, FPGA, and DAC . We will discuss the design of the RF system and how it relates to the support of cavity testing

RF Breakdown Studies Using a 1.3 GHZ Test Cell

International Nuclear Information System (INIS)

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

2009-01-01

Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Recent studies have shown that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas without the need for long conditioning times, because the dense gas can dramatically reduce dark currents and multipacting. In this project we use this high pressure technique to suppress effects of residual vacuum and geometry found in evacuated cavities to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. A 1.3-GHz RF test cell with replaceable electrodes (e.g. Mo, Cu, Be, W, and Nb) and pressure barrier capable of operating both at high pressure and in vacuum has been designed and built, and preliminary testing has been completed. A series of detailed experiments is planned at the Argonne Wakefield Accelerator. At the same time, computer simulations of the RF Breakdown process will be carried out to help develop a consistent physics model of RF Breakdown. In order to study the effect of the radiofrequency on RF Breakdown, a second test cell will be designed, fabricated, and tested at a lower frequency, most likely 402.5 MHz.

Performance of 3.9 GHz SRF cavities at Fermilab's ILCTA_MDB nhorizontal test stand

Energy Technology Data Exchange (ETDEWEB)

Harms, Elvin; Hocker, Andy; /Fermilab

2008-08-01

Fermilab is building a cryomodule containing four 3.9 GHz superconducting radio frequency (SRF) cavities for the Free electron LASer in Hamburg (FLASH) facility at the Deutsches Elektronen-SYnchrotron (DESY) laboratory. Before assembling the cavities into the cryomodule, each individual cavity is tested at Fermilab's Horizontal Test Stand (HTS). The HTS provides the capability to test fully-dressed SRF cavities at 1.8 K with high-power pulsed RF in order to verify that the cavities achieve performance requirements under these conditions. The performance at the HTS of the 3.9 GHz cavities built for FLASH is presented here.

RF pulse compression in the NLC test accelerator at SLAC

International Nuclear Information System (INIS)

Lavine, T.L.

1995-01-01

At the Stanford Linear Accelerator Center (SLAC), we are designing a Next Linear Collider (NLC) with linacs powered by X-band klystrons with rf pulse compression. The design of the linac rf system is based on X-band prototypes which have been tested at high power, and on a systems-integration test---the Next Linear Collider Test Accelerator (NLCTA)---which is currently under construction at SLAC. This paper discusses some of the systems implications of rf pulse compression, and the use of pulse compression in the NLCTA, both for peak power multiplication and for controlling, by rf phase modulation, intra-pulse variations in the linac beam energy. copyright 1995 American Institute of Physics

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Characterizing the Performance of the Princeton Advanced Test Stand Ion Source

Science.gov (United States)

Stepanov, A.; Gilson, E. P.; Grisham, L.; Kaganovich, I.; Davidson, R. C.

2012-10-01

The Princeton Advanced Test Stand (PATS) is a compact experimental facility for studying the physics of intense beam-plasma interactions relevant to the Neutralized Drift Compression Experiment - II (NDCX-II). The PATS facility consists of a multicusp RF ion source mounted on a 2 m-long vacuum chamber with numerous ports for diagnostic access. Ar+ beams are extracted from the source plasma with three-electrode (accel-decel) extraction optics. The RF power and extraction voltage (30 - 100 kV) are pulsed to produce 100 μsec duration beams at 0.5 Hz with excellent shot-to-shot repeatability. Diagnostics include Faraday cups, a double-slit emittance scanner, and scintillator imaging. This work reports measurements of beam parameters for a range of beam energies (30 - 50 keV) and currents to characterize the behavior of the ion source and extraction optics. Emittance scanner data is used to calculate the beam trace-space distribution and corresponding transverse emittance. If the plasma density is changing during a beam pulse, time-resolved emittance scanner data has been taken to study the corresponding evolution of the beam trace-space distribution.

The MuCool Test Area and RF Program

International Nuclear Information System (INIS)

Torun, Y.; Huang, D.; Norem, J.; Palmer, Robert B.; Stratakis, Diktys; Bross, A.; Chung, M.; Jansson, A.; Moretti, A.; Yonehara, K.; Li, D.

2010-01-01

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

LEDA RF distribution system design and component test results

International Nuclear Information System (INIS)

Roybal, W.T.; Rees, D.E.; Borchert, H.L.; McCarthy, M.; Toole, L.

1998-01-01

The 350 MHz and 700 MHz RF distribution systems for the Low Energy Demonstration Accelerator (LEDA) have been designed and are currently being installed at Los Alamos National Laboratory. Since 350 MHz is a familiar frequency used at other accelerator facilities, most of the major high-power components were available. The 700 MHz, 1.0 MW, CW RF delivery system designed for LEDA is a new development. Therefore, high-power circulators, waterloads, phase shifters, switches, and harmonic filters had to be designed and built for this applications. The final Accelerator Production of Tritium (APT) RF distribution systems design will be based on much of the same technology as the LEDA systems and will have many of the RF components tested for LEDA incorporated into the design. Low power and high-power tests performed on various components of these LEDA systems and their results are presented here

High power tests of X-band RF windows at KEK

Energy Technology Data Exchange (ETDEWEB)

Otake, Yuji [Earthquake Research Inst., Tokyo Univ., Tokyo (Japan); Tokumoto, Shuichi; Kazakov, Sergei Yu.; Odagiri, Junichi; Mizuno, Hajime

1997-04-01

Various RF windows comprising a short pill-box, a long pill-box, a TW (traveling wave)-mode and three TE11-mode horn types have been developed for an X-band high-power pulse klystron with two output windows for JLC (Japan Linear Collider). The output RF power of the klystron is designed to be 130 MW with the 800 ns pulse duration. Since this X-band klystron has two output windows, the maximum RF power of the window must be over 85 MW. The design principle for the windows is to reduce the RF-power density and/or the electric-field strength at the ceramic part compared with that of an ordinary pill-box-type window. Their reduction is effective to increase the handling RF power of the window. To confirm that the difference among the electric-field strengths depends on their RF structures, High-power tests of the above-mentioned windows were successfully carried out using a traveling-wave resonator (TWR) for the horns and the TW-mode type and, installing them directly to klystron output waveguides for the short and long pill-box type. Based upon the operation experience of S-band windows, two kinds of ceramic materials were used for these tests. The TE11-mode 1/2{lambda}g-1 window was tested up to the RF peak-power of 84 MW with the 700 ns pulse duration in the TWR. (J.P.N)

RF Power Requirements for PEFP SRF Cavity Test

International Nuclear Information System (INIS)

Kim, Han Sung; Seol, Kyung Tae; Kwon, Hyeok Jung; Cho, Yong Sub

2011-01-01

For the future extension of the PEFP (Proton Engineering Frontier Project) Proton linac, preliminary study on the SRF (superconducting radio-frequency) cavity is going on including a five-cell prototype cavity development to confirm the design and fabrication procedures and to check the RF and mechanical properties of a low-beta elliptical cavity. The main parameters of the cavity are like followings. - Frequency: 700 MHz - Operating mode: TM010 pi mode - Cavity type: Elliptical - Geometrical beta: 0.42 - Number of cells: 5 - Accelerating gradient: 8 MV/m - Epeak/Eacc: 3.71 - Bpeak/Eacc: 7.47 mT/(MV/m) - R/Q: 102.3 ohm - Epeak: 29.68 MV/m (1.21 Kilp.) - Geometrical factor: 121.68 ohm - Cavity wall thickness: 4.3 mm - Stiffening structure: Double ring - Effective length: 0.45 m For the test of the cavity at low temperature of 4.2 K, many subsystems are required such as a cryogenic system, RF system, vacuum system and radiation shielding. RF power required to generate accelerating field inside cavity depends on the RF coupling parameters of the power coupler and quality factor of the SRF cavity and the quality factor itself is affected by several factors such as operating temperature, external magnetic field level and surface condition. Therefore, these factors should be considered to estimate the required RF power for the SRF cavity test

Variable Attitude Test Stand

Data.gov (United States)

Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

Beam property measurement of a 300-kV ion source test stand for a 1-MV electrostatic accelerator

Science.gov (United States)

Park, Sae-Hoon; Kim, Dae-Il; Kim, Yu-Seok

2016-09-01

The KOMAC (Korea Multi-purpose Accelerator Complex) has been developing a 300-kV ion source test stand for a 1-MV electrostatic accelerator for industrial purposes. A RF ion source was operated at 200 MHz with its matching circuit. The beam profile and emittance were measured behind an accelerating column to confirm the beam property from the RF ion source. The beam profile was measured at the end of the accelerating tube and at the beam dump by using a beam profile monitor (BPM) and wire scanner. An Allison-type emittance scanner was installed behind the beam profile monitor (BPM) to measure the beam density in phase space. The measurement results for the beam profile and emittance are presented in this paper.

Development of new S-band RF window for stable high-power operation in linear accelerator RF system

Science.gov (United States)

Joo, Youngdo; Lee, Byung-Joon; Kim, Seung-Hwan; Kong, Hyung-Sup; Hwang, Woonha; Roh, Sungjoo; Ryu, Jiwan

2017-09-01

For stable high-power operation, a new RF window is developed in the S-band linear accelerator (Linac) RF systems of the Pohang Light Source-II (PLS-II) and the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The new RF window is designed to mitigate the strength of the electric field at the ceramic disk and also at the waveguide-cavity coupling structure of the conventional RF window. By replacing the pill-box type cavity in the conventional RF window with an overmoded cavity, the electric field component perpendicular to the ceramic disk that caused most of the multipacting breakdowns in the ceramic disk was reduced by an order of magnitude. The reduced electric field at the ceramic disk eliminated the Ti-N coating process on the ceramic surface in the fabrication procedure of the new RF window, preventing the incomplete coating from spoiling the RF transmission and lowering the fabrication cost. The overmoded cavity was coupled with input and output waveguides through dual side-wall coupling irises to reduce the electric field strength at the waveguide-cavity coupling structure and the possibility of mode competitions in the overmoded cavity. A prototype of the new RF window was fabricated and fully tested with the Klystron peak input power, pulse duration and pulse repetition rate of 75 MW, 4.5 μs and 10 Hz, respectively, at the high-power test stand. The first mass-produced new RF window installed in the PLS-II Linac is running in normal operation mode. No fault is reported to date. Plans are being made to install the new RF window to all S-band accelerator RF modules of the PLS-II and PAL-XFEL Linacs. This new RF window may be applied to the output windows of S-band power sources like Klystron as wells as the waveguide windows of accelerator facilities which operate in S-band.

Test results of the Los Alamos ferrite-tuned rf cavity

International Nuclear Information System (INIS)

Friedrichs, C.C.; Spalek, G.; Carlini, R.D.; Smythe, W.R.

1987-03-01

An rf accelerating cavity appropriate for use in a 20% frequency bandwidth synchrotron has been designed, fabricated, and is now being tested at Los Alamos. The cavity-amplifier system was designed to produce a peak rf gap voltage of 90 kV over the range from 50 to 60 MHz. Special features of the system are the transversely biased ferrite tuner, capacitive coupling of the amplifier to the cavity, and a 15-cm beam pipe. High-power rf testing of the cavity-amplifier system started in August 1986, using an adjustable dc power supply to bias the ferrite. This paper describes the cavity-amplifier circuit and the test results to the present time. Future plans are also discussed

Reliability and fatigue characteristics of a standing hip isometric endurance protocol.

Science.gov (United States)

Mutchler, Jessica A; Weinhandl, Joshua T; Hoch, Matthew C; Van Lunen, Bonnie L

2015-08-01

Muscle fatigue is a common consideration when evaluating and rehabilitating athletic injuries. The presence of muscular fatigue has been previously determined by quantifying median frequency (MF) through a power spectral analysis on EMG signals collected throughout an endurance task. Research has not yet determined if a prolonged isometric test in a standing position generates muscular fatigue of the hip. The purpose of this study was to determine the reliability and fatigue characteristics of a standing hip isometric endurance test. Twenty healthy participants completed one 60-s Maximum Voluntary Isometric Contraction of standing hip flexion, extension, adduction, and abduction. MF of the participants' dominant limb rectus femoris (RF), biceps femoris (BF), gluteus maximus (GMax), gluteus medius (GMed) and adductor longus (ADD) was determined via surface electromyography during two sessions, 30-min apart. Reliability values (ICC2,1) were moderate-to-excellent for all time intervals of each action (FlexionRF: >0.80; ExtensionBF: >0.89; ExtensionGMax: >0.60; AdductionADD: >0.78; AbductionGMed: >0.60) and MF significantly decreased over time for all actions. Results suggest the endurance test is a reliable technique to generate muscular fatigue for hip flexion, extension, adduction and abduction. It can be used as a time efficient fatigue protocol specific to the RF, BF, GMax, ADD and GMed. Copyright © 2015 Elsevier Ltd. All rights reserved.

An Automated 476 MHz RF Cavity Processing Facility at SLAC

CERN Document Server

McIntosh, P; Schwarz, H

2003-01-01

The 476 MHz accelerating cavities currently used at SLAC are those installed on the PEP-II B-Factory collider accelerator. They are designed to operate at a maximum accelerating voltage of 1 MV and are routinely utilized on PEP-II at voltages up to 750 kV. During the summer of 2003, SPEAR3 will undergo a substantial upgrade, part of which will be to replace the existing 358.54 MHz RF system with essentially a PEP-II high energy ring (HER) RF station operating at 476.3 MHz and 3.2 MV (or 800 kV/cavity). Prior to installation, cavity RF processing is required to prepare them for use. A dedicated high power test facility is employed at SLAC to provide the capability of conditioning each cavity up to the required accelerating voltage. An automated LabVIEW based interface controls and monitors various cavity and test stand parameters, increasing the RF fields accordingly such that stable operation is finally achieved. This paper describes the high power RF cavity processing facility, highlighting the features of t...

Studies of RF sheaths and diagnostics on IShTAR

Energy Technology Data Exchange (ETDEWEB)

Crombé, K., E-mail: Kristel.Crombe@UGent.be [Department of Applied Physics, Ghent University, Ghent (Belgium); LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Devaux, S.; Faudot, E.; Heuraux, S.; Moritz, J. [YIJL, UMR7198 CNRS-Université de Lorraine, Nancy (France); D’Inca, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Ochoukov, R. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Louche, F.; Tripsky, M.; Van Eester, D.; Wauters, T. [LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Noterdaeme, J.-M. [Department of Applied Physics, Ghent University, Ghent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

2015-12-10

IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetised plasma test facility for RF sheaths studies at the Max-Planck-Institut für Plasmaphysik in Garching. In contrast to a tokamak, a test stand provides more liberty to impose the parameters and gives better access for the instrumentation and antennas. The project will support the development of diagnostic methods for characterising RF sheaths and validate and improve theoretical predictions. The cylindrical vacuum vessel has a diameter of 1 m and is 1.1 m long. The plasma is created by an external cylindrical plasma source equipped with a helical antenna that has been designed to excite the m=1 helicon mode. In inductive mode, plasma densities and electron temperatures have been characterised with a planar Langmuir probe as a function of gas pressure and input RF power. A 2D array of RF compensated Langmuir probes and a spectrometer are planned. A single strap RF antenna has been designed; the plasma-facing surface is aligned to the cylindrical plasma to ease the modelling. The probes will allow direct measurements of plasma density profiles in front of the RF antenna, and thus a detailed study of the density modifications induced by RF sheaths, which influences the coupling. The RF antenna frequency has been chosen to study different plasma wave interactions: the accessible plasma density range includes an evanescent and propagative behaviour of slow or fast waves, and allows the study of the effect of the lower hybrid resonance layer.

Stand for testing the electrical race car engine

Science.gov (United States)

Baier, M.; Franiasz, J.; Mierzwa, P.; Wylenzek, D.

2015-11-01

An engine test stand created especially for research of electrical race car is described in the paper. The car is an aim of Silesian Greenpower project whose participants build and test electrical vehicles to take part in international races in Great Britain. The engine test stand is used to test and measure the characteristics of vehicles and their engines. It has been designed particularly to test the electric cars engineered by students of Silesian Greenpower project. The article contains a description how the test stand works and shows its versatility in many areas. The paper presents both construction of the test stand, control system and sample results of conducted research. The engine test stand was designed and modified using PLM Siemens NX 8.5. The construction of the test stand is highly modular, which means it can be used both for testing the vehicle itself or for tests without the vehicle. The test stand has its own wheel, motor, powertrain and braking system with second engine. Such solution enables verifying various concepts without changing the construction of the vehicle. The control system and measurement system are realized by enabling National Instruments product myRIO (RIO - Reconfigurable Input/Output). This controller in combination with powerful LabVIEW environment performs as an advanced tool to control torque and speed simultaneously. It is crucial as far as the test stand is equipped in two motors - the one being tested and the braking one. The feedback loop is realized by an optical encoder cooperating with the rotor mounted on the wheel. The results of tests are shown live on the screen both as a chart and as single values. After performing several tests there is a report generated. The engine test stand is widely used during process of the Silesian Greenpower vehicle design. Its versatility enables powertrain testing, wheels and tires tests, thermal analysis and more.

Performance test of lower hybrid waveguide under long/high-RF power transmission

International Nuclear Information System (INIS)

Seki, Masami; Obara, Kenjiro; Maebara, Sunao

1996-06-01

Performance tests of a module for lower hybrid waveguides were carried out at the CEA Cadarache RF Test Facility. For the experiments the test module was fabricated by JAERI, the transmission line of the test bed was modified and the connection waveguides were manufactured by CEA. As the results, the thermal treatment by baking at a higher temperature was the most effective for reducing outgassing during injection of high RF power. The outgassing strongly depended on the temperature of the test module, but was independent to initial temperature. The RF injection reduced outgassing. The outgassing rate decreased to a low level of 10 -6 -10 -5 Pa m 3 /sec m 2 (10 -9 -10 -8 Torr 1/sec cm 2 ) at 400degC after 450degC-baking. The gas injection did not affect outgassing before and during RF injection. The baking under H 2 or D 2 gas atmosphere were not so effective for reducing outgassing rate. The outgassing rate did not depend on input RF power densities. The temperature in central part of the test module saturated to be ∼100degC by using of water cooling at a power level of 150 MW/m 2 RF injection, and a neutral gas pressure decreased gradually. In the water cooling case, the outgassing rate was very low less than 10 -7 Pa m 3 /sec m 2 (10 -10 Torr 1/sec cm 2 ). The steady state RF injection was demonstrated with water cooling. (author)

High-voltage test stand at Livermore

International Nuclear Information System (INIS)

Smith, M.E.

1977-01-01

This paper describes the present design and future capability of the high-voltage test stand for neutral-beam sources at Lawrence Livermore Laboratory. The stand's immediate use will be for testing the full-scale sources (120 kV, 65 A) for the Tokamak Fusion Test Reactor. It will then be used to test parts of the sustaining source system (80 kV, 85 A) being designed for the Magnetic Fusion Test Facility. Following that will be an intensive effort to develop beams of up to 200 kV at 20 A by accelerating negative ions. The design of the test stand features a 5-MVA power supply feeding a vacuum tetrode that is used as a switch and regulator. The 500-kW arc supply and the 100-kW filament supply for the neutral-beam source are battery powered, thus eliminating one or two costly isolation transformers

Performance test of lower hybrid waveguide under long/high-RF power transmission

Energy Technology Data Exchange (ETDEWEB)

Seki, Masami; Obara, Kenjiro; Maebara, Sunao [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; and others

1996-06-01

Performance tests of a module for lower hybrid waveguides were carried out at the CEA Cadarache RF Test Facility. For the experiments the test module was fabricated by JAERI, the transmission line of the test bed was modified and the connection waveguides were manufactured by CEA. As the results, the thermal treatment by baking at a higher temperature was the most effective for reducing outgassing during injection of high RF power. The outgassing strongly depended on the temperature of the test module, but was independent to initial temperature. The RF injection reduced outgassing. The outgassing rate decreased to a low level of 10{sup -6}-10{sup -5} Pa m{sup 3}/sec m{sup 2} (10{sup -9}-10{sup -8} Torr 1/sec cm{sup 2}) at 400degC after 450degC-baking. The gas injection did not affect outgassing before and during RF injection. The baking under H{sub 2} or D{sub 2} gas atmosphere were not so effective for reducing outgassing rate. The outgassing rate did not depend on input RF power densities. The temperature in central part of the test module saturated to be {approx}100degC by using of water cooling at a power level of 150 MW/m{sup 2} RF injection, and a neutral gas pressure decreased gradually. In the water cooling case, the outgassing rate was very low less than 10{sup -7} Pa m{sup 3}/sec m{sup 2} (10{sup -10} Torr 1/sec cm{sup 2}). The steady state RF injection was demonstrated with water cooling. (author).

Low Level RF Including a Sophisticated Phase Control System for CTF3

CERN Document Server

Mourier, J; Nonglaton, J M; Syratchev, I V; Tanner, L

2004-01-01

CTF3 (CLIC Test Facility 3), currently under construction at CERN, is a test facility designed to demonstrate the key feasibility issues of the CLIC (Compact LInear Collider) two-beam scheme. When completed, this facility will consist of a 150 MeV linac followed by two rings for bunch-interleaving, and a test stand where 30 GHz power will be generated. In this paper, the work that has been carried out on the linac's low power RF system is described. This includes, in particular, a sophisticated phase control system for the RF pulse compressor to produce a flat-top rectangular pulse over 1.4 µs.

Modification of 300kV RF Ion Source for 1-MV Electrostatic Accelerator at KOMAC

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae-Il; Kwon, Hyeok-Jung; Park, Sae-Hoon; Cho, Yong-Sub [KOMAC, Gyeongju (Korea, Republic of)

2015-05-15

The specifications of the 1-MV electrostatic accelerator are shown as below. High voltage power supply is electron transformer rectifier (ELV) type which was developed in Nuclear Physics Institute (Novosibirsk) for industrial electron accelerators. And accelerator column consists of alumina and metal electrode rings were 0.5m-long brazed structure which can be installed horizontally. In case of ion source for 1-MV electrostatic accelerator, it is chosen a thonemann type rf ion source and 300-kV test-stand was made up to confirm the stable operating conditions. High voltage power supply is fabricated by domestic company, and its operation has been confirming at KOMAC site. Equally, the ion source of 300-kV test-stand should be modified to install into the high voltage power supply. In this paper, modification of ion source of 300-kV test-stand for 1-MV electrostatic accelerator is presented and its processes are considered. 300-kV RF ion source and power supply are testing for the 1-MV electrostatic accelerator and trying for combination between them. The 1-MV electrostatic accelerator will be fabricated with domestic companies and tested in the beam application research building at KOMAC.

Modification of 300kV RF Ion Source for 1-MV Electrostatic Accelerator at KOMAC

International Nuclear Information System (INIS)

Kim, Dae-Il; Kwon, Hyeok-Jung; Park, Sae-Hoon; Cho, Yong-Sub

2015-01-01

The specifications of the 1-MV electrostatic accelerator are shown as below. High voltage power supply is electron transformer rectifier (ELV) type which was developed in Nuclear Physics Institute (Novosibirsk) for industrial electron accelerators. And accelerator column consists of alumina and metal electrode rings were 0.5m-long brazed structure which can be installed horizontally. In case of ion source for 1-MV electrostatic accelerator, it is chosen a thonemann type rf ion source and 300-kV test-stand was made up to confirm the stable operating conditions. High voltage power supply is fabricated by domestic company, and its operation has been confirming at KOMAC site. Equally, the ion source of 300-kV test-stand should be modified to install into the high voltage power supply. In this paper, modification of ion source of 300-kV test-stand for 1-MV electrostatic accelerator is presented and its processes are considered. 300-kV RF ion source and power supply are testing for the 1-MV electrostatic accelerator and trying for combination between them. The 1-MV electrostatic accelerator will be fabricated with domestic companies and tested in the beam application research building at KOMAC

Gas Generation Testing of Spherical Resorcinol-Formaldehyde (sRF) Resin

Energy Technology Data Exchange (ETDEWEB)

Colburn, Heather A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Camaioni, Donald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mahoney, Lenna A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Adami, Susan R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2018-01-19

This report describes gas generation testing of the spherical resorcinol-formaldehyde (sRF) resin that was conducted to support the technology maturation of the LAWPS facility. The current safety basis for the LAWPS facility is based primarily on two studies that had limited or inconclusive data sets. The two studies indicated a 40% increase in hydrogen generation rate of water (as predicted by the Hu model) with sRF resin over water alone. However, the previous studies did not test the range of conditions (process fluids and temperatures) that are expected in the LAWPS facility. Additionally, the previous studies did not obtain replicate test results or comparable liquid-only control samples. All of the testing described in this report, conducted with water, 0.45M nitric acid, and waste simulants with and without sRF resin, returned hydrogen generation rates that are within the current safety basis for the facility of 1.4 times the Hu model output for water.

RF Testing Of Microwave Integrated Circuits

Science.gov (United States)

Romanofsky, R. R.; Ponchak, G. E.; Shalkhauser, K. A.; Bhasin, K. B.

1988-01-01

Fixtures and techniques are undergoing development. Four test fixtures and two advanced techniques developed in continuing efforts to improve RF characterization of MMIC's. Finline/waveguide test fixture developed to test submodules of 30-GHz monolithic receiver. Universal commercially-manufactured coaxial test fixture modified to enable characterization of various microwave solid-state devices in frequency range of 26.5 to 40 GHz. Probe/waveguide fixture is compact, simple, and designed for non destructive testing of large number of MMIC's. Nondestructive-testing fixture includes cosine-tapered ridge, to match impedance wavequide to microstrip. Advanced technique is microwave-wafer probing. Second advanced technique is electro-optical sampling.

Commissioning and early operating experience with the Fermilab horizontal test facility

Energy Technology Data Exchange (ETDEWEB)

Carcagno, R.; Chase, B.; Harms, E.; Hocker, A.; Prieto, P.; Reid, J.; Rowe, A.; Theilacker, J.; Votava, M.; /Fermilab

2007-10-01

Fermilab has constructed a facility for testing dressed superconducting radiofrequency (RF) cavities at 1.8 K with high-power pulsed RF. This test stand was designed to test both 9-cell 1.3 GHz TESLA-style cavities and 9-cell 3.9 GHz cavities being built by Fermilab for DESY's TTF-FLASH facility. An overview of the test stand and a description of its initial commissioning is described here.

Practical RF system design

CERN Document Server

Egan, William F

2003-01-01

he ultimate practical resource for today's RF system design professionals Radio frequency components and circuits form the backbone of today's mobile and satellite communications networks. Consequently, both practicing and aspiring industry professionals need to be able to solve ever more complex problems of RF design. Blending theoretical rigor with a wealth of practical expertise, Practical RF System Design addresses a variety of complex, real-world problems that system engineers are likely to encounter in today's burgeoning communications industry with solutions that are not easily available in the existing literature. The author, an expert in the field of RF module and system design, provides powerful techniques for analyzing real RF systems, with emphasis on some that are currently not well understood. Combining theoretical results and models with examples, he challenges readers to address such practical issues as: * How standing wave ratio affects system gain * How noise on a local oscillator will affec...

Design for the National RF Test Facility at ORNL

International Nuclear Information System (INIS)

Gardner, W.L.; Hoffman, D.J.; Becraft, W.R.

1983-01-01

Conceptual and preliminary engineering design for the National RF Test Facility at Oak Ridge National Laboratory (ORNL) has been completed. The facility will comprise a single mirror configuration embodying two superconducting development coils from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program on either side of a cavity designed for full-scale antenna testing. The coils are capable of generating a 1.2-T field at the axial midpoint between the coils separated by 1.0 m. The vacuum vessel will be a stainless steel, water-cooled structure having an 85-cm-radius central cavity. The facility will have the use of a number of continuous wave (cw), radio-frequency (rf) sources at levels including 600 kW at 80 MHz and 100 kW at 28 GHz. Several plasma sources will provide a wide range of plasma environments, including densities as high as approx. 5 x 10 13 cm -3 and temperatures on the order of approx. 10 eV. Furthermore, a wide range of diagnostics will be available to the experimenter for accurate appraisal of rf testing

Proposed rf system for the fusion materials irradiation test facility

International Nuclear Information System (INIS)

Fazio, M.V.; Johnson, H.P.; Hoffert, W.J.; Boyd, T.J.

1979-01-01

Preliminary rf system design for the accelerator portion of the Fusion Materials Irradiation Test (FMIT) Facility is in progress. The 35-MeV, 100-mA, cw deuteron beam will require 6.3 MW rf power at 80 MHz. Initial testing indicates the EIMAC 8973 tetrode is the most suitable final amplifier tube for each of a series of 15 amplifier chains operating at 0.5-MW output. To satisfy the beam dynamics requirements for particle acceleration and to minimize beam spill, each amplifier output must be controlled to +-1 0 in phase and the field amplitude in the tanks must be held within a 1% tolerance. These tolerances put stringent demands on the rf phase and amplitude control system

Compact RF ion source for industrial electrostatic ion accelerator

Energy Technology Data Exchange (ETDEWEB)

Kwon, Hyeok-Jung, E-mail: hjkwon@kaeri.re.kr; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub [Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongsangbukdo 38180 (Korea, Republic of)

2016-02-15

Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

Compact RF ion source for industrial electrostatic ion accelerator

Science.gov (United States)

Kwon, Hyeok-Jung; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub

2016-02-01

Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

RF System description for the ground test accelerator radio-frequency quadrupole

International Nuclear Information System (INIS)

Regan, A.H.; Brittain, D.; Rees, D.E.; Ziomek, D.

1992-01-01

This paper describes the RF system being used to provide RF power and to control the cavity field for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system, and RF Reference generation subsystem, and a tetrode as a high-power amplifier (HPA) that can deliver up to 300 kW of peak power to the RFQ cavity at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I and Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5 degrees in phase in the presence of beam-induced instabilities

ICH antenna development on the ORNL RF Test Facility

International Nuclear Information System (INIS)

Gardner, W.L.; Bigelow, T.S.; Haste, G.R.; Hoffman, D.J.; Livesey, R.L.

1987-01-01

A compact resonant loop antenna is installed on the ORNL Radio Frequency Test Facility (RFTF). Facility characteristics include a steady-state magnetic field of ∼ 0.5 T at the antenna, microwave-generated plasmas with n e ∼ 10 12 cm -3 and T e ∼ 8 eV, and 100 kW of 25-MHz rf power. The antenna is tunable from ∼22--75 MHz, is designed to handle ≥1 MW of rf power, and can be moved 5 cm with respect to the port flange. Antenna characteristics reported and discussed include the effect of magnetic field on rf voltage breakdown at the capacitor, the effects of magnetic field and plasma on rf voltage breakdown between the radiating element and the Faraday shield, the effects of graphite on Faraday shield losses, and the efficiency of coupling to the plasma. 2 refs., 4 figs

High power test of RF window and coaxial line in vacuum

International Nuclear Information System (INIS)

Sun, D.; Champion, M.; Gormley, M.; Kerns, Q.; Koepke, K.; Moretti, A.

1993-01-01

Primary rf input couplers for the superconducting accelerating cavities of the TESLA electron linear accelerator test to be performed at DESY, Hamburg, Germany are under development at both DESY and Fermilab. The input couplers consist of a WR650 waveguide to coaxial line transition with an integral ceramic window, a coaxial connection to the superconducting accelerating cavity with a second ceramic window located at the liquid nitrogen heat intercept location, and bellows on both sides of the cold window to allow for cavity motion during cooldown, coupling adjustments and easier assembly. To permit in situ high peak power processing of the TESLA superconducting accelerating cavities, the input couplers are designed to transmit nominally 1 ms long, 2 MW peak, 1.3 GHz rf pulses from the WR650 waveguide at room temperature to the cavities at 1.8 K. The coaxial part of the Fermilab TESLA input coupler design has been tested up to 1.7 MW using the prototype 805 MHz rf source located at the A0 service building of the Tevatron. The rf source, the testing system and the test results are described

Assembly and installation of the large coil test facility test stand

International Nuclear Information System (INIS)

Queen, C.C. Jr.

1983-01-01

The Large Coil Test Facility (LCTF) was built to test six tokamak-type superconducting coils, with three to be designed and built by US industrial teams and three provided by Japan, Switzerland, and Euratom under an international agreement. The facility is designed to test these coils in an environment which simulates that of a tokamak. The heart of this facility is the test stand, which is made up of four major assemblies: the Gravity Base Assembly, the Bucking Post Assembly, the Torque Ring Assembly, and the Pulse Coil Assembly. This paper provides a detailed review of the assembly and installation of the test stand components and the handling and installation of the first coil into the test stand

High power tests of dressed supconducting 1.3 GHz RF cavities

Energy Technology Data Exchange (ETDEWEB)

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

2011-03-01

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

IR-RF dating of sand-sized K-feldspar extracts: A test of accuracy

DEFF Research Database (Denmark)

Buylaert, Jan-Pieter; Jain, Mayank; Murray, A.S.

2012-01-01

In this paper we use a recently developed radioluminescence (RL) attachment to the Risø TL/OSL reader to test the InfraRed-RadioFluorescence (IR-RF) dating method applied to K-feldspar rich extracts from our known-age archive samples. We present experiments to characterise the instrument performa......In this paper we use a recently developed radioluminescence (RL) attachment to the Risø TL/OSL reader to test the InfraRed-RadioFluorescence (IR-RF) dating method applied to K-feldspar rich extracts from our known-age archive samples. We present experiments to characterise the instrument...... performance and to test the reproducibility of IR-RF measurements. These experiments illustrate the high sensitivity and dose rate of our RL system, the negligible influence of the turntable movement on IR-RF signals and the effectiveness of the built in 395 nm LED at bleaching IR-RF signals. We measure IR......-RF ages on a set of samples with independent age control using a robust analytical method, which is able to detect any possible sensitivity change. Our IR-RF ages do not agree well with the independent age control; the ages of the younger samples (20–45 ka) are significantly over-estimated while the ages...

Methodology for performing RF reliability experiments on a generic test structure

NARCIS (Netherlands)

Sasse, G.T.; de Vries, Rein J.; Schmitz, Jurriaan

2007-01-01

This paper discusses a new technique developed for generating well defined RF large voltage swing signals for on wafer experiments. This technique can be employed for performing a broad range of different RF reliability experiments on one generic test structure. The frequency dependence of a

HIGH POWER TESTS OF A MULTIMODE X-BAND RF DISTRIBUTION SYSTEMS

International Nuclear Information System (INIS)

Tantawi, S

2004-01-01

We present a multimode X-band rf pulse compression system suitable for the Next Linear Collider (NLC). The NLC main linacs operate at 11.424 GHz. A single NLC rf unit is required which produce 400 ns pulses with 600 MW of peak power. Each rf unit should power approximately 5 meters of accelerator structures. These rf units consist of two 75 MW klystrons and a dual-moded resonant delay line pulse compression system [1] that produce a flat output pulse. The pulse compression system components are all over moded and most components are design to operate with two modes at the same time. This approach allows increasing the power handling capabilities of the system while maintain a compact inexpensive system. We detail the design of this system and present experimental cold test results. The high power testing of the system is verified using four 50-MW solenoid focused klystrons. These Klystrons should be able to push the system beyond NLC requirements

RF study and 3-D simulations of a side-coupling thermionic RF-gun

International Nuclear Information System (INIS)

Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

2014-01-01

A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012 © . RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance

RF study and 3-D simulations of a side-coupling thermionic RF-gun

Science.gov (United States)

Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

2014-02-01

A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012©. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

Theoretical investigation of a travelling-wave rf gun

International Nuclear Information System (INIS)

Gao, J.

1991-12-01

A travelling-wave type rf gun (TW gun) is investigated theoretically. Analytical formulae concerning energy gain, energy spread, and transverse emittance are derived. After showing the corresponding formulae for the standing-wave rf gun (SW gun), comparisons are made between the two types of rf gun. Finally, some numerical results are calculated to demonstrate further the behaviours of the TW gun, and to compare with those from analytical formulae. (author) 11 refs.; 27 figs

RF and microwave integrated circuit development technology, packaging and testing

CERN Document Server

Gamand, Patrice; Kelma, Christophe

2018-01-01

RF and Microwave Integrated Circuit Development bridges the gap between existing literature, which focus mainly on the 'front-end' part of a product development (system, architecture, design techniques), by providing the reader with an insight into the 'back-end' part of product development. In addition, the authors provide practical answers and solutions regarding the choice of technology, the packaging solutions and the effects on the performance on the circuit and to the industrial testing strategy. It will also discuss future trends and challenges and includes case studies to illustrate examples. * Offers an overview of the challenges in RF/microwave product design * Provides practical answers to packaging issues and evaluates its effect on the performance of the circuit * Includes industrial testing strategies * Examines relevant RF MIC technologies and the factors which affect the choice of technology for a particular application, e.g. technical performance and cost * Discusses future trends and challen...

Initial test of an rf gun with a GaAs cathode installed

International Nuclear Information System (INIS)

Aulenbacher, K.; Bossart, R.; Braun, H.

1996-09-01

The operation of an rf gun with a GaAs crystal installed as the cathode has been tested in anticipation of eventually producing a polarized electron beam for a future e + /e - collider using an rf photoinjector

A Cryogenic Test Stand for Large Superconducting Solenoid Magnets

Energy Technology Data Exchange (ETDEWEB)

Rabehl, R. [Fermilab; Carcagno, R. [Fermilab; Nogiec, J. [Fermilab; Orris, D. [Fermilab; Soyars, W. [Fermilab; Sylvester, C. [Fermilab

2013-01-01

A new test stand for testing large superconducting solenoid magnets at the Fermilab Central Helium Liquifier (CHL) has been designed, and operated. This test stand has been used to test a coupling coil for the Muon Ionization Cooling Experiment (MICE), and future uses include solenoids for the Fermilab mu2e experiment. This paper describes the test stand design and operation including controlled cool-down and warm-up. Overviews of the process controls system and the quench management system are also included.

Cooling tests of the cryomodules at superconducting RF test facility (STF)

International Nuclear Information System (INIS)

Ohuchi, Norihito; Nakai, Hirotaka; Kojima, Yuuji

2009-01-01

KEK has been constructing the Superconducting RF Test Facility (STF) with aiming at a center of the ILC-R and D in Asia from 2005. In this project, KEK targets manufacturing and operational experiences of the RF cavity and cryomodule toward the ILC, and two cryomodules have been developed. These cryomodules are 6 meter long and have 4 nine-cell cavities in each cryostat. The designs of the cryomodules are based on the TESLA Type-3 (TTF-3) at DESY, however, each cryostat has the different type of cavities, TESLA-like type and Low-Loss type. The tests of the cryomodules were performed in two steps. In the first test, measurements of the cryogenic performances of these cryomodules were the main objective. One nine-cell cavity was assembled in each cryomodule and cool-down of the two cryomodules was performed, individually. In the second test, the four TESLA-like cavities were assembled in the cryomodule as complete integration. Cool-down of the cryomodule to 2 K was successfully completed, and thermal performances of the cryomodule and cooling capacity of the cryogenics system were studied in detail. In this paper, we will report the design of the cryomodules and the thermal performances at these cold tests. (author)

Status of superconducting RF test facility (STF)

International Nuclear Information System (INIS)

Hayano, Hitoshi

2005-01-01

A superconducting technology was recommended for the main linac design of the International Linear Collider (ILC) by the International Technology Recommendation Panel (ITRP). The basis for this design has been developed and tested at DESY, and R and D is progressing at many laboratories around the world including DESY, Orsay, KEK, FNAL, SLAC, Cornell, and JLAB. In order to promote Asian SC-technology for ILC, construction of a test facility in KEK was discussed and decided. The role and status of the superconducting RF test facility (STF) is reported in this paper. (author)

RF study and 3-D simulations of a side-coupling thermionic RF-gun

Energy Technology Data Exchange (ETDEWEB)

Rimjaem, S., E-mail: sakhorn.rimjaem@cmu.ac.th [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand); Kusoljariyakul, K.; Thongbai, C. [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand)

2014-02-01

A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012{sup ©}. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

Cryomodule tests of four Tesla-like cavities in the Superconducting RF Test Facility at KEK

Directory of Open Access Journals (Sweden)

Eiji Kako

2010-04-01

Full Text Available A 6-m cryomodule including four Tesla-like cavities was developed, and was tested in the Superconducting RF Test Facility phase-I at KEK. The performance as a total superconducting cavity system was checked in the cryomodule tests at 2 K with high rf power. One of the four cavities achieved a stable pulsed operation at 32  MV/m, which is higher than the operating accelerating gradient in the ILC. The maximum accelerating gradient (E_{acc,max⁡} obtained in the vertical cw tests was maintained or slightly improved in the cryomodule tests operating in a pulse mode. Compensation of the Lorentz force detuning at 31  MV/m was successfully demonstrated by a piezo tuner and predetuning.

Isopropyl alcohol tank installed at A-3 Test Stand

Science.gov (United States)

2009-01-01

An isopropyl alcohol (IPA) tank is lifted into place at the A-3 Test Stand being built at NASA's John C. Stennis Space Center. Fourteen IPA, water and liquid oxygen (LOX) tanks are being installed to support the chemical steam generators to be used on the A-3 Test Stand. The IPA and LOX tanks will provide fuel for the generators. The water will allow the generators to produce steam that will be used to reduce pressure inside the stand's test cell diffuser, enabling operators to simulate altitudes up to 100,000 feet. In that way, operators can perform the tests needed on rocket engines being built to carry humans back to the moon and possibly beyond. The A-3 Test Stand is set for completion and activation in 2011.

The RF system for FELI linac

International Nuclear Information System (INIS)

Morii, Y.; Abe, S.; Keishi, T.; Tomimasu, T.

1995-01-01

FELI (Free Electron Laser Research Institute, Inc.) is constructing a Free Electron Laser facility covering from 20μm (infra red region) to 0.35μm (ultra violet region), using as S-band linac. The linac consists of a thermoionic 0.5ns-pulse triggered gun, a 714-MHz SHB (subharmonic buncher), a 2856-MHz standing wave type buncher, and seven ETL (Electro-technical Laboratory) type accelerating sections. An RF system of the linac for FELs is required of long pulse duration and high stability. Two S-band klystrons (TOSHIBA E3729) are operated in three pulse operation modes (pulse width and peak RF power): 24μs-24MW, 12.5μs-34MW, 0.5μs-70MW. Each klystron modulator has a PFN consisting of 4 parallel networks of 24 capacitors and 24 variable inductors, and it has a line switch of an optical thyristor stack. An S-band klystron and its modulator were combined to test their performance at the works of NISSIN ELECTRIC Co. in December 1993. These equipments were installed at FELI in January 1994. The design and experimental results of the RF system are summarized in this paper. (author)

Rf system description for the ground test accelerator radio-frequency quadrupole

International Nuclear Information System (INIS)

Regan, A.H.; Brittain, D.; Rees, D.E.; Ziomek, D.

1992-01-01

This paper describes the RF system being used to provide RF power and to control the cavity field used for the ground test accelerator (GTA) radio-frequency quadrupole (RFQ). The RF system consists of a low-level RF (LLRF) control system that uses a tetrode as a high-power amplifier (HPA) as part of its plant to deliver up to 300 kW of peak power to the RFQ at a 2% duty factor. The LLRF control system implements in-phase and quadrature (I ampersand Q) control to maintain the cavity field within tolerances of 0.5% in amplitude and 0.5 degrees in phase in the presence of beam-induced instabilities. This paper describes the identified components and presents measured performance data. The user interface with the systems is described, and cavity field measurements are included

RF power source for the compact linear collider test facility (CTF3)

CERN Document Server

McMonagle, G; Brown, Peter; Carron, G; Hanni, R; Mourier, J; Rossat, G; Syratchev, I V; Tanner, L; Thorndahl, L

2004-01-01

The CERN CTF3 facility will test and demonstrate many vital components of CLIC (Compact Linear Collider). This paper describes the pulsed RF power source at 2998.55 MHz for the drive-beam accelerator (DBA), which produces a beam with an energy of 150 MeV and a current of 3.5 Amps. Where possible, existing equipment from the LEP preinjector, especially the modulators and klystrons, is being used and upgraded to achieve this goal. A high power RF pulse compression system is used at the output of each klystron, which requires sophisticated RF phase programming on the low level side to achieve the required RF pulse. In addition to the 3 GHz system two pulsed RF sources operating at 1.5 GHz are being built. The first is a wide-band, low power, travelling wave tube (TWT) for the subharmonic buncher (SHB) system that produces a train of "phase coded" subpulses as part of the injector scheme. The second is a high power narrow band system to produce 20 MW RF power to the 1.5 GHz RF deflectors in the delay loop situate...

Low power microwave tests on RF gun prototype of the Iranian Light Source Facility

Directory of Open Access Journals (Sweden)

A Sadeghipanah

2017-08-01

Full Text Available In this paper, we introduce RF electron gun of Iranian Light Source Facility (ILSF pre-injection system. Design, fabrication and low-power microwave tests results of the prototype RF electron gun have been described in detail. This paper also explains the tuning procedure of the prototype RF electron gun to the desired resonant frequency. The outcomes of this project brighten the path to the fabrication of the RF electron gun by the local industries  

Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests.

Directory of Open Access Journals (Sweden)

Cristina Roldán-Jiménez

Full Text Available Sit-to-stand (STS tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG, biceps femoris (BF, vastus medialis of the quadriceps (QM, the abdominal rectus (AR, erector spinae (ES, rectus femoris (RF, soleus (SO and the tibialis anterior (TA. Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects.

Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests.

Science.gov (United States)

Roldán-Jiménez, Cristina; Bennett, Paul; Cuesta-Vargas, Antonio I

2015-01-01

Sit-to-stand (STS) tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG), biceps femoris (BF), vastus medialis of the quadriceps (QM), the abdominal rectus (AR), erector spinae (ES), rectus femoris (RF), soleus (SO) and the tibialis anterior (TA). Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Development and performance test of a new high power RF window in S-band PLS-II LINAC

Science.gov (United States)

Hwang, Woon-Ha; Joo, Young-Do; Kim, Seung-Hwan; Choi, Jae-Young; Noh, Sung-Ju; Ryu, Ji-Wan; Cho, Young-Ki

2017-12-01

A prototype of RF window was developed in collaboration with the Pohang Accelerator Laboratory (PAL) and domestic companies. High power performance tests of the single RF window were conducted at PAL to verify the operational characteristics for its application in the Pohang Light Source-II (PLS-II) linear accelerator (Linac). The tests were performed in the in-situ facility consisting of a modulator, klystron, waveguide network, vacuum system, cooling system, and RF analyzing equipment. The test results with Stanford linear accelerator energy doubler (SLED) have shown no breakdown up to 75 MW peak power with 4.5 μs RF pulse width at a repetition rate of 10 Hz. The test results with the current operation level of PLS-II Linac confirm that the RF window well satisfies the criteria for PLS-II Linac operation.

High-voltage terminal test of a test stand for a 1-MV electrostatic accelerator

Science.gov (United States)

Park, Sae-Hoon; Kim, Yu-Seok

2015-10-01

The Korea Multipurpose Accelerator Complex has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source and accelerating tube will be installed in a high-pressure vessel. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz radio-frequency power supply, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. The results of the 300-kV high-voltage terminal tests are presented in this paper.

Superconducting RF separator for Omega Spectrometer

CERN Multimedia

1977-01-01

The photo shows an Nb-deflector for the superconducting RF separator ready for installation in its cryostat (visible at the back). Each deflector was about 3 m long. L. Husson and P. Skacel (Karlsruhe) stand on the left, A. Scharding (CERN) stands on the right. This particle separator, the result of a collaboration between the Gesellshaft für Kernforschung, Karlsruhe, and CERN was installed in the S1 beam line to Omega spectrometer. (See Annual Report 1977.)

IR-RF dating of sand-sized K-feldspar extracts: A test of accuracy

International Nuclear Information System (INIS)

Buylaert, J.-P.; Jain, M.; Murray, A.S.; Thomsen, K.J.; Lapp, T.

2012-01-01

In this paper we use a recently developed radioluminescence (RL) attachment to the Risø TL/OSL reader to test the InfraRed-RadioFluorescence (IR-RF) dating method applied to K-feldspar rich extracts from our known-age archive samples. We present experiments to characterise the instrument performance and to test the reproducibility of IR-RF measurements. These experiments illustrate the high sensitivity and dose rate of our RL system, the negligible influence of the turntable movement on IR-RF signals and the effectiveness of the built in 395 nm LED at bleaching IR-RF signals. We measure IR-RF ages on a set of samples with independent age control using a robust analytical method, which is able to detect any possible sensitivity change. Our IR-RF ages do not agree well with the independent age control; the ages of the younger samples (20–45 ka) are significantly over-estimated while the ages of the older samples (∼130 ka) are significantly under-estimated. Experiments are undertaken to investigate this disagreement and our results indicate that they can most likely be explained by 1) the difficulty of defining the correct bleaching level prior to regeneration measurements, 2) signal instability, 3) sensitivity changes between the additive dose and regenerative dose measurements, or a combination of these three factors.

Safety assessment for the rf Test Facility

International Nuclear Information System (INIS)

Nagy, A.; Beane, F.

1984-08-01

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

A high voltage test stand for electron gun qualification for LINACs

International Nuclear Information System (INIS)

Wanmode, Yashwant D.; Mulchandani, J.; Acharya, M.; Bhisikar, A.; Singh, H.G.; Shrivastava, Purushottam

2011-01-01

An electron gun lest stand has been developed at RRCAT. The test stand consists of a high voltage pulsed power supply, electron gun filament supply, grid supply, UHV system and electron gun current measurement system. Several electron guns developed indigenously were evaluated on this test stand. The shielding is provided for the electron gun set up. Electron gun tests can be tested upto 55 kV with pulse width of 15 microsecs and pulse repetition rates up to 200 Hz. The technical details of the subsystems are furnished and results of performance of the test stand have been reported in this paper. (author)

Test Stand for Linear Induction Accelerator Optimization

International Nuclear Information System (INIS)

Ong, M; DeHope, B; Griffin, K; Goerz, D; Kihara, R; Vogtlin, G; Zentler, J M; Scarpetti, R

2003-01-01

Lawrence Livermore National Laboratory has designed and constructed a test stand to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot size. Studying the interaction of the beam and pulse-power system with the accelerator cell will improve the design of high-current accelerators at Livermore and elsewhere. On the test stand, a standard FXR cell is driven by a flexible pulse-power system and the beam current is simulated with a switched center conductor. The test stand is fully instrumented with high-speed digitizers to document the effect of impedance mismatches when the cell is operated under various full-voltage conditions. A time-domain reflectometry technique was also developed to characterize the beam and cell interactions by measuring the impedance of the accelerator and pulse-power component. Computer models are being developed in parallel with the testing program to validate the measurements and evaluate different design changes. Both 3D transient electromagnetic and circuit models are being used

First cold test of TESLA superconducting RF cavity in horizontal cryostat (CHECHIA)

International Nuclear Information System (INIS)

Kuzminski, J.

1996-01-01

In the framework of the TESLA project, the horizontal cryostat (CHECHIA) was built to test a superconducting RF cavity equipped with its helium vessel, magnetic shielding, cold tuner, main coupler and higher order modes couplers under realistic conditions before final assembly of eight cavities into TESLA Test Facility cryo-module. The results of the first cold tests in CHECHIA, performed at DESY with a 9-cell cavity (C19) to be used in the TTF injector are presented. Additional measurements of mechanical stability under RF operation (frequency variation with He pressure, Lorentz detuning) and cryogenic and electric measurements of power dissipation are presented. (author)

RF Processing Experience with the GTF Prototype RF Gun

International Nuclear Information System (INIS)

Schmerge, J.F.

2010-01-01

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 π 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).

High power testing of a 17 GHz photocathode RF gun

International Nuclear Information System (INIS)

Chen, S.C.; Danly, B.G.; Gonichon, J.

1995-01-01

The physics and technological issues involved in high gradient particle acceleration at high microwave (RF) frequencies are under study at MIT. The 17 GHz photocathode RF gun has a 1 1/2 cell (π mode) room temperature cooper cavity. High power tests have been conducted at 5-10 MW levels with 100 ns pulses. A maximum surface electric field of 250 MV/m was achieved. This corresponds to an average on-axis gradient of 150 MeV/m. The gradient was also verified by a preliminary electron beam energy measurement. Even high gradients are expected in our next cavity design

Design and construction of the advanced photon source 352-MHz rf system switching control

International Nuclear Information System (INIS)

Horan, D.; Solita, L.; Reigle, D.; Dimonte, N.

1997-01-01

A switching control system has been designed and built to provide the capability of rapidly switching the waveguide and low-level cabling between different klystrons to operate the Advanced Photon Source storage ring in the event of a failure of a klystron system or to perform necessary repairs and preventative maintenance. The twelve possible modes of operation allow for complete redundancy of the booster synchrotron rf system and either a maximum of two storage ring rf systems to be completely off-line or one system to be used as a power source for an rf test stand. A programmable controller is used to send commands to intermediate control panels which interface to WR2300 waveguide switches and phase shifters, rf cavity interlock and low-level rf distribution systems, and klystron power supply controls for rapid reconfiguration of the rf systems in response to a mode-selection command. Mode selection is a local manual operation using a keyswitch arrangement which prevents more than one mode from being selected at a time. The programmable controller also monitors for hardware malfunction and guards against open-quotes hot-switchingclose quotes of the rf systems. The rf switching controls system is monitored via the Experimental Physics and Industrial Control System (EPICS) for remote system status check

A Cryogenic Test Stand for LHC Quadrupole Magnets

International Nuclear Information System (INIS)

Carcagno, R.H.; Huang, Y.; Orris, D.F.; Peterson, T.J.; Rabehl, R.J.

2004-01-01

A new test stand for testing LHC interaction region (IR) quadrupole magnets at the Fermilab Magnet Test Facility has been designed and operated. The test stand uses a double bath system with a lambda plate to provide the magnet with a stagnant bath of pressurized He II at 1.9 K and 0.13 MPa. A cryostated magnet 0.91 m in diameter and up to 13 m in length can be accommodated. This paper describes the system design and operation. Issues related to both 4.5 K and 1.9 K operations and magnet quenching are highlighted. An overview of the data acquisition and cryogenics controls systems is also included

Use of phase information with a stepper motor to control frequency for tuning system of the Front End Test Stand Radio Frequency Quadrupole at Rutherford Appleton Laboratory

Energy Technology Data Exchange (ETDEWEB)

Alsari, S., E-mail: s.alsari@imperial.ac.uk; Aslaninejad, M.; Pozimski, J.

2015-03-01

For the Front End Test Stand (FETS) linear accelerator project at the Rutherford Appleton Laboratory in the UK, a 4 m, 4 vanes Radio Frequency Quadrupole (RFQ) with a resonant frequency of 324 MHz has been designed. The RF power feeding the RFQ gives rise to the temperature increase in the RFQ, which in turn, results in shifting the resonant frequency of the RFQ. The frequency shift and the stability in the RFQ frequency can be maintained based on the reflected power or signal phase information. We have, however, investigated restoration of the RFQ nominal frequency based on the RF signal phases driving a stepper motor. The concept and the system set-up and electronics are described in detail. Results of the measurements indicating the full restoration of the RFQ nominal frequency based on the RF signal phases and stepper motor are presented. Moreover, measured sensitivity of tuner with respect to its position is given.

Use of phase information with a stepper motor to control frequency for tuning system of the Front End Test Stand Radio Frequency Quadrupole at Rutherford Appleton Laboratory

International Nuclear Information System (INIS)

Alsari, S.; Aslaninejad, M.; Pozimski, J.

2015-01-01

For the Front End Test Stand (FETS) linear accelerator project at the Rutherford Appleton Laboratory in the UK, a 4 m, 4 vanes Radio Frequency Quadrupole (RFQ) with a resonant frequency of 324 MHz has been designed. The RF power feeding the RFQ gives rise to the temperature increase in the RFQ, which in turn, results in shifting the resonant frequency of the RFQ. The frequency shift and the stability in the RFQ frequency can be maintained based on the reflected power or signal phase information. We have, however, investigated restoration of the RFQ nominal frequency based on the RF signal phases driving a stepper motor. The concept and the system set-up and electronics are described in detail. Results of the measurements indicating the full restoration of the RFQ nominal frequency based on the RF signal phases and stepper motor are presented. Moreover, measured sensitivity of tuner with respect to its position is given

Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) scores generated from the MMPI-2 and MMPI-2-RF test booklets: internal structure comparability in a sample of criminal defendants.

Science.gov (United States)

Tarescavage, Anthony M; Alosco, Michael L; Ben-Porath, Yossef S; Wood, Arcangela; Luna-Jones, Lynn

2015-04-01

We investigated the internal structure comparability of Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) scores derived from the MMPI-2 and MMPI-2-RF booklets in a sample of 320 criminal defendants (229 males and 54 females). After exclusion of invalid protocols, the final sample consisted of 96 defendants who were administered the MMPI-2-RF booklet and 83 who completed the MMPI-2. No statistically significant differences in MMPI-2-RF invalidity rates were observed between the two forms. Individuals in the final sample who completed the MMPI-2-RF did not statistically differ on demographics or referral question from those who were administered the MMPI-2 booklet. Independent t tests showed no statistically significant differences between MMPI-2-RF scores generated with the MMPI-2 and MMPI-2-RF booklets on the test's substantive scales. Statistically significant small differences were observed on the revised Variable Response Inconsistency (VRIN-r) and True Response Inconsistency (TRIN-r) scales. Cronbach's alpha and standard errors of measurement were approximately equal between the booklets for all MMPI-2-RF scales. Finally, MMPI-2-RF intercorrelations produced from the two forms yielded mostly small and a few medium differences, indicating that discriminant validity and test structure are maintained. Overall, our findings reflect the internal structure comparability of MMPI-2-RF scale scores generated from MMPI-2 and MMPI-2-RF booklets. Implications of these results and limitations of these findings are discussed. © The Author(s) 2014.

The RF system of FELI

International Nuclear Information System (INIS)

Morii, Y.; Miyauchi, Y.; Koga, A.; Abe, H.; Keishi, T.; Bessho, I.; Tomimasu, T.

1994-01-01

FELI (Free Electron Laser Research Institute, Inc.) is constructing a Free Electron Laser facility covering from 20 μm (infra red region) to 0.35 μm (ultra violet region), using an S-band linac. The building will be completed in November 1993 and installation of the linac will start in December 1993. The linac consists of a thermoionic 0.5ns-pulse triggered gun, a 714 MHz SHB (subharmonic buncher), a 2856 MHz standing wave type buncher, and 7 ETL (Electrotechnical Laboratory) type accelerating sections. An RF system of the linac for FELs is required of long pulse duration and high stability. S-band klystrons (TOSHIBA E3729) are operated in three pulse operation modes (pulse width and peak RF power); 24 μs - 24 MW, 12.5 μs - 34 MW, 0.5 μs - 70 MW. Each klystron modulator has the PFN consisting of 4 parallel networks of 24 capacitors and 24 inductors, and it has a line switch of an optical thyristor stack. These equipments are manufactured now, and an S-band klystron and modulator will be combined to test their performance at the works of NISSIN ELECTRIC Co. in October 1993. (author)

High power RF performance test of an improved SiC load

Energy Technology Data Exchange (ETDEWEB)

Hwang, W.H.; Kim, S.H.; Park, Y.J. [Pohang Accelerator Lab., Pohang Inst. of Sceince and Technology, Pohang (KR)] [and others

1998-11-01

Two prototypes of SiC loads sustaining a maximum peak power of 50 MW were fabricated by Nihon Koshuha Co. in Japan. The PAL conducted the high power RF performance tests of SiC loads to verify the operation characteristics for the application to the PLS Linac. The in-situ facility for the K 12 module was used for the test, which consists of a modulator and klystron system, waveguide network, vacuum and cooling system, and RF analyzing equipment. As the test results, no breakdown appeared up to 50 MW peak power of 1 {mu}s pulse width at a repetition rate of 50 Hz. However, as the peak power increased above 20 MW at 4 {mu}s with 10 Hz, the breakdown phenomena has been observed. Analysing the test results with the current operation power level of PLS Linac, it is confirmed that the SiC loads well satisfy the criteria of the PLS Linac operation. (author)

Associations between MMPI-2-RF validity scale scores and extra-test measures of personality and psychopathology.

Science.gov (United States)

Forbey, Johnathan D; Lee, Tayla T C; Ben-Porath, Yossef S; Arbisi, Paul A; Gartland, Diane

2013-08-01

The current study explored associations between two potentially invalidating self-report styles detected by the Validity scales of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF), over-reporting and under-reporting, and scores on the MMPI-2-RF substantive, as well as eight collateral self-report measures administered either at the same time or within 1 to 10 days of MMPI-2-RF administration. Analyses were conducted with data provided by college students, male prisoners, and male psychiatric outpatients from a Veterans Administration facility. Results indicated that if either an over- or under-reporting response style was suggested by the MMPI-2-RF Validity scales, scores on the majority of the MMPI-2-RF substantive scales, as well as a number of collateral measures, were significantly affected in all three groups in the expected directions. Test takers who were identified as potentially engaging in an over- or under-reporting response style by the MMPI-2-RF Validity scales appeared to approach extra-test measures similarly regardless of when these measures were administered in relation to the MMPI-2-RF. Limitations and suggestions for future study are discussed.

Stroboscopic topographies on iron borate crystal in 9.6 MHz rf magnetic field

International Nuclear Information System (INIS)

Mitsui, Takaya; Imai, Yasuhiko; Kikuta, Seishi

2003-01-01

The influence of magnetoacoustic wave on the crystal deformation was studied by stroboscopic double crystal X-ray topography. The acoustic wave was excited by the rf magnetic field, which was synchronized with synchrotron radiation X-ray pulse. In measured rocking curves of FeBO 3 (4 4 4) reflection, we observed, for the first time, that the application of rf magnetic field (|H rf | max >8.4 Oe) brought about the extreme narrowing of full width at half maximum (FWHM). Recorded topographs showed that the narrowing of FWHM was due to the magnetoacoustic standing wave which is excited in FeBO 3 crystal. In our experiments, the influence of additional static magnetic field on the magnetoacoustic standing wave of FeBO 3 crystal was investigated too

Langmuir probe studies on a RF ion source for NBI

International Nuclear Information System (INIS)

McNeely, P.; Heineman, B.; Kraus, W.; Riedl, R.; Speth, E.; Vollmer, O.

2001-01-01

IPP Garching has been developing a RF ion source for H - production. In order to improve the data quality a new scanning probe system with passive RF compensation has been installed on the Type VI ion source on the BATMAN test stand. Using this probe, measurements have been carried out to study changes to the plasma parameters (electron density, electron temperature, and plasma potential) due to variation in the source operating conditions. The data were collected at a source pressure of 0.5 Pa and with 60±5 kW applied RF power. Presented are some of the results of these measurements, focusing on the effect of: argon seeding, addition of Cs to the source, and the newly added Faraday screen. The electron density behaves in a fashion that agrees with the theory of ambipolar diffusion. Typically there is little change to the average electron energy observed regardless of which effect is considered. The plasma potential shows the most significant changes with external source conditions, both in value for all cases and shape when the Faraday screen was added

Results of the SLAC LCLS Gun High-Power RF Tests

International Nuclear Information System (INIS)

Dowell, D.H.; Jongewaard, E.; Limborg-Deprey, C.; Schmerge, J.F.; Li, Z.; Xiao, L.; Wang, J.; Lewandowski, J.; Vlieks, A.

2007-01-01

The beam quality and operational requirements for the Linac Coherent Light Source (LCLS) currently being constructed at SLAC are exceptional, requiring the design of a new RF photocathode gun for the electron source. Based on operational experience at SLAC's GTF and SDL and ATF at BNL as well as other laboratories, the 1.6cell s-band (2856MHz) gun was chosen to be the best electron source for the LCLS, however a significant redesign was necessary to achieve the challenging parameters. Detailed 3-D analysis and design was used to produce near-perfect rotationally symmetric rf fields to achieve the emittance requirement. In addition, the thermo-mechanical design allows the gun to operate at 120Hz and a 140MV/m cathode field, or to an average power dissipation of 4kW. Both average and pulsed heating issues are addressed in the LCLS gun design. The first LCLS gun is now fabricated and has been operated with high-power RF. The results of these high-power tests are presented and discussed

X-Band RF Gun Development

International Nuclear Information System (INIS)

Vlieks, A.E.

2012-01-01

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.

Stand for visual ultrasonic testing of spent fuel

International Nuclear Information System (INIS)

Czajkowski, W.; Borek-Kruszewska, E.

2001-01-01

A stand for visual and ultrasonic testing of spent fuel, constructed under Strategic Governmental Programme for management of spent fuel and radioactive waste, is presented in the paper. The stand, named 'STEND-1', built up at the Institute of Atomic Energy in Swjerk, is appointed for underwater visual testing of spent fuel elements type MR6 and WWR by means of TV-CCD camera and image processing system and for ultrasonic scanning of external surface of these elements by means of video scan immersion transducer and straight UHT connector. 'STEND-1' is built using flexible in use, high-tensile, anodized aluminum profiles. All the profiles feature longitudinal grooves to accommodate connecting elements and for the attachment of accessories at any position. They are also characterised by straight-through core bores for use with standard fastening elements and to accommodate accessory components. Stand, equipped with automatic control and processing system based on personal computer, may be manually or automatically controlled. Control system of movements of the camera in the vertical axis and rotational movement of spent fuel element permits to fix chosen location of fuel element with accuracy better than 0.1 mm. High resolution of ultrasonic method allows to record damages of outer surface of order 0.1 mm. The results of visual testing of spent fuel are recorded on video tape and then may be stored on the hard disc of the personal computer and presented in shape of photo or picture. Only selected damage surfaces of spent fuel elements are tested by means of ultrasonic scanning. All possibilities of the stand and results of visual testing of spent fuel type WWR are presented in the paper. (author)

Fast thermometry for superconducting rf cavity testing

International Nuclear Information System (INIS)

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

2007-01-01

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

Fast thermometry for superconducting rf cavity testing

Energy Technology Data Exchange (ETDEWEB)

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

2007-06-01

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

Development of an item bank for the EORTC Role Functioning Computer Adaptive Test (EORTC RF-CAT)

DEFF Research Database (Denmark)

Gamper, Eva-Maria; Petersen, Morten Aa.; Aaronson, Neil

2016-01-01

a computer-adaptive test (CAT) for RF. This was part of a larger project whose objective is to develop a CAT version of the EORTC QLQ-C30 which is one of the most widely used HRQOL instruments in oncology. METHODS: In accordance with EORTC guidelines, the development of the RF-CAT comprised four phases...... with good psychometric properties. The resulting item bank exhibits excellent reliability (mean reliability = 0.85, median = 0.95). Using the RF-CAT may allow sample size savings from 11 % up to 50 % compared to using the QLQ-C30 RF scale. CONCLUSIONS: The RF-CAT item bank improves the precision...

Data acquisition system for PLT Neutral Beam Test Stand

International Nuclear Information System (INIS)

Francis, J.E. Jr.; Hammons, C.E.

1977-01-01

The PLT Neutral Beam Test Stand at Oak Ridge National Laboratory was constructed to test and condition powerful neutral beam sources for the Princeton Large Torus experiment at Princeton Plasma Physics Laboratory. The data acquisition system for the test stand monitors the beam characteristics and power output to determine if the beam is operating at its design specifications. The high speed of the computer system is utilized to provide near-real-time analysis of experimental data. The analysis of the data is presented as numerical tabulation and graphic display

Comparison of Test Stand and Helicopter Oil Cooler Bearing Condition Indicators

Science.gov (United States)

Dempsey, Paula J.; Branning, Jeremy; Wade, Damiel R.; Bolander, Nathan

2010-01-01

The focus of this paper was to compare the performance of HUMS condition indicators (CI) when detecting a bearing fault in a test stand or on a helicopter. This study compared data from two sources: first, CI data collected from accelerometers installed on two UH-60 Black Hawk helicopters when oil cooler bearing faults occurred, along with data from helicopters with no bearing faults; and second, CI data that was collected from ten cooler bearings, healthy and faulted, that were removed from fielded helicopters and installed in a test stand. A method using Receiver Operating Characteristic (ROC) curves to compare CI performance was demonstrated. Results indicated the bearing energy CI responded differently for the helicopter and the test stand. Future research is required if test stand data is to be used validate condition indicator performance on a helicopter.

Cryogenic studies of rf accelerating structures, vintage 1978

International Nuclear Information System (INIS)

Liska, D.; Uher, J.; Potter, J.

1986-01-01

Cryogenically cooled rf cavity studies were undertaken at Los Alamos in 1978 to test the effectiveness of reduced temperature on the Q-enhancement of 450-MHz drift-tube linac structures. A complete facility was set up to do high power tests, not only at liquid nitrogen (LN 2 ) temperature but with liquid hydrogen (LH 2 ) as well. The cavity, Dewar, klystron test stand, and a remote outdoor enclosure were constructed. Hydrogen safety approval for the tests was obtained. Unfortunately, the hydrogen tests were never done. However, the cavity was tested at high power in LN 2 and a Q-enhancement of 2.02 was recorded, compared to 2.7 expected theoretically. This work is now continuing with improved measuring techniques using some of the same apparatus. It is the purpose of this paper to report on the early work and to reference its continuation today

Cryogenics for a vertical test stand facility for testing superconducting radio frequency cavities at RRCAT

International Nuclear Information System (INIS)

Gupta, Prabhat Kumar; Kumar, Manoj; Kush, P.K.

2015-01-01

Vertical Test Stand (VTS) Facility is located in a newly constructed building of Cryo-Engineering and Cryo-Module Development Division (CCDD). This test facility is one of the important facilities to develop SCRF technologies for superconducting accelerators like Indian Spallation Neutron Source. VTS has to be used for regular testing of the Superconducting Radio Frequency (SRF) Niobium cavities at nominal frequency of 1.3 GHz/ 650 MHz at 4 K / 2 K liquid helium (LHe) bath temperatures. Testing of these cavities at 2 K evaluates cavity processing methods, procedures and would also serve as a pre-qualification test for cavity to test it in horizontal cryostat, called horizontal test stand, with other cavity components such as tuner and helium vessel. Cryogenic technologies play a major role in these cavity testing facilities. Achieving and maintaining a stable temperature of 2 K in these test stands on regular and reliable basis is a challenging task and require broad range of cryogenic expertise, large scale system level understanding and many in-house technological and process developments. Furthermore this test stand will handle large amount of liquid helium. Therefore, an appropriately designed infrastructure is required to handle such large amount of helium gas generated during the operation of VTS .This paper describes the different cryogenic design aspects, initial cryogenic operation results and different cryogenic safety aspects. (author)

A cryogenic test stand for full length SSC magnets with superfluid capability

International Nuclear Information System (INIS)

Peterson, T.J.; Mazur, P.O.

1989-02-01

The Fermilab Magnet Test Facility performs testing of the full scale SSC magnets on test stands capable of simulating the cryogenic environment of the SSC main ring. One of these test stands, Stand 5, also has the ability to operate the magnet under test at temperatures from 1.8K to 4.5K with either supercritical helium or subcooled liquid, providing at least 25 Watts of refrigeration. At least 50 g/s flow is available from 2.3K to 4.5K, whereas superfluid operation occurs with zero flow. Cooldown time from 4.5K to 1.8K is 1.5 hours. A maximum current capability of 10,000 amps is provided, as is instrumentation to monitor and control the cryogenic conditions. This paper describes the cryogenic design of this test stand. 8 refs., 6 figs

Engineering design of vertical test stand cryostat

International Nuclear Information System (INIS)

Suhane, S.K.; Sharma, N.K.; Raghavendra, S.; Joshi, S.C.; Das, S.; Kush, P.K.; Sahni, V.C.; Gupta, P.D.; Sylvester, C.; Rabehl, R.; Ozelis, J.

2011-01-01

Under Indian Institutions and Fermilab collaboration, Raja Ramanna Centre for Advanced Technology and Fermi National Accelerator Laboratory are jointly developing 2K Vertical Test Stand (VTS) cryostats for testing SCRF cavities at 2K. The VTS cryostat has been designed for a large testing aperture of 86.36 cm for testing of 325 MHz Spoke resonators, 650 MHz and 1.3 GHz multi-cell SCRF cavities for Fermilab's Project-X. Units will be installed at Fermilab and RRCAT and used to test cavities for Project-X. A VTS cryostat comprises of liquid helium (LHe) vessel with internal magnetic shield, top insert plate equipped with cavity support stand and radiation shield, liquid nitrogen (LN 2 ) shield and vacuum vessel with external magnetic shield. The engineering design and analysis of VTS cryostat has been carried out using ASME B and PV Code and Finite Element Analysis. Design of internal and external magnetic shields was performed to limit the magnetic field inside LHe vessel at the cavity surface 2 shield has been performed to check the effectiveness of LN 2 cooling and for compliance with ASME piping code allowable stresses.

Development of small C-band standing-wave accelerator structure

International Nuclear Information System (INIS)

Miura, S.; Takahashi, A.; Hisanaga, N.; Sekido, H.; Yoshizumi, A.

2000-01-01

We have newly developed a compact C-band (5712 MHz) standing-wave accelerator for the medical product/waste sterilization applications. The accelerator consists of an electron gun operating at 25 kV DC followed by a single-cell pre-buncher and 3-cell buncher section, and 11-cell of the side-coupled standing-wave accelerating structure. The total length including the electron gun is about 600 mm. The first high-power test was performed in March 2000, where the accelerator successively generated the electron beam of 9 MeV energy and 160 mA peak-current at 3.8 MW RF input power. Mitsubishi Heavy Industry starts to serve the sterilization systems using C-band accelerator reported here, and also supplies the accelerator components for the medical oncology applications. (author)

Performance test of personal RF monitor for area monitoring at magnetic confinement fusion facility

International Nuclear Information System (INIS)

Tanaka, M.; Uda, T.; Wang, J.; Fujiwara, O.

2012-01-01

For safety management at a magnetic confinement fusion-test facility, protection from not only ionising radiation, but also non-ionising radiation such as the leakage of static magnetic and electromagnetic fields is an important issue. Accordingly, the use of a commercially available personal RF monitor for multipoint area monitoring is proposed. In this study, the performance of both fast- and slow-type personal RF monitors was investigated by using a transverse electromagnetic cell system. The range of target frequencies was between 10 and 300 MHz, corresponding to the ion cyclotron range of frequency in a fusion device. The personal RF monitor was found to have good linearity, frequency dependence and isotropic response. However, the time constant for the electric field sensor of the slow-type monitor was much longer than that for the fast-type monitor. Considering the time-varying field at the facility, it is found that the fast-type monitor is suitable for multipoint monitoring at magnetic confinement fusion test facilities. (authors)

The SSRL linacs for injection to the storage ring and rf gun testing

International Nuclear Information System (INIS)

Park, Sanghyun; Weaver, James N.

1996-01-01

The Stanford Synchrotron Radiation Laboratory (SSRL) operates two linac systems. One has three SLAC type linac sections powered by two klystrons for injection of electrons at 120 MeV into the booster ring, boosting the energy to 2.3 GeV to fill the SPEAR. After the ramping, the SPEAR stores up to 100 mA of the beam at 3.0 GeV. The preinjector consists of a thermionic RF gun, an alpha magnet, and a chopper along with focusing magnets. The other has one 10 foot section powered by the injector klystron for the testing of RF gun with photocathode, which is driven by a separate klystron. This paper describes present systems with their operational parameters, followed by plans for the upgrades and RF gun development efforts at the SSRL. (author)

Large-scale generic test stand for testing of multiple configurations of air filters utilizing a range of particle size distributions

Science.gov (United States)

Giffin, Paxton K.; Parsons, Michael S.; Unz, Ronald J.; Waggoner, Charles A.

2012-05-01

The Institute for Clean Energy Technology (ICET) at Mississippi State University has developed a test stand capable of lifecycle testing of high efficiency particulate air filters and other filters specified in American Society of Mechanical Engineers Code on Nuclear Air and Gas Treatment (AG-1) filters. The test stand is currently equipped to test AG-1 Section FK radial flow filters, and expansion is currently underway to increase testing capabilities for other types of AG-1 filters. The test stand is capable of producing differential pressures of 12.45 kPa (50 in. w.c.) at volumetric air flow rates up to 113.3 m3/min (4000 CFM). Testing is performed at elevated and ambient conditions for temperature and relative humidity. Current testing utilizes three challenge aerosols: carbon black, alumina, and Arizona road dust (A1-Ultrafine). Each aerosol has a different mass median diameter to test loading over a wide range of particles sizes. The test stand is designed to monitor and maintain relative humidity and temperature to required specifications. Instrumentation is implemented on the upstream and downstream sections of the test stand as well as on the filter housing itself. Representative data are presented herein illustrating the test stand's capabilities. Digital images of the filter pack collected during and after testing is displayed after the representative data are discussed. In conclusion, the ICET test stand with AG-1 filter testing capabilities has been developed and hurdles such as test parameter stability and design flexibility overcome.

Beam instrumentation for an ISOL test stand

International Nuclear Information System (INIS)

Mackenzie, G.H.; Dombsky, M.; Rawnsley, W.; Stanford, G.; Yin, Y.; Novikov, A.

1995-09-01

TRIUMF is constructing a test bed for the first stages of the proposed TISAC accelerated radioactive beam facility. The authors will present the requirements for the diagnostic system for this test stand and describe the design and development work underway. Scintillators, beamstops and a Faraday Cup have been tested using stable, mass analyzed, 12 keV beams of ions from mass 14 to 132. The design of a linear drive, with 10 microm resolution, for scanning wires and slits has begun

Beam instrumentation for an ISOL test stand

International Nuclear Information System (INIS)

Mackenzie, G.H.; Dombsky, M.; Rawnsley, W.; Stanford, G.; Yin, Y.; Novikov, A.

1995-09-01

TRIUMF is constructing a test bed for the first stages of the proposed TISAC accelerated radioactive beam facility. We will present the requirements for the diagnostic system for this test stand and describe the design and development work underway. Scintillators, beamstops and Faraday Cup have been tested using stable, mass analyzed, 12 keV beams of ions from mass 14 to 132. The design of a linear drive, with 10 μm resolution, for scanning wires and slits has begun. (author)

A stand alone computer system to aid the development of mirror fusion test facility RF heating systems

International Nuclear Information System (INIS)

Thomas, R.A.

1983-01-01

The Mirror Fusion Test Facility (MFTF-B) control system architecture requires the Supervisory Control and Diagnostic System (SCDS) to communicate with a LSI-11 Local Control Computer (LCC) that in turn communicates via a fiber optic link to CAMAC based control hardware located near the machine. In many cases, the control hardware is very complex and requires a sizable development effort prior to being integrated into the overall MFTF-B system. One such effort was the development of the Electron Cyclotron Resonance Heating (ECRH) system. It became clear that a stand alone computer system was needed to simulate the functions of SCDS. This paper describes the hardware and software necessary to implement the SCDS Simulation Computer (SSC). It consists of a Digital Equipment Corporation (DEC) LSI-11 computer and a Winchester/Floppy disk operating under the DEC RT-11 operating system. All application software for MFTF-B is programmed in PASCAL, which allowed us to adapt procedures originally written for SCDS to the SSC. This nearly identical software interface means that software written during the equipment development will be useful to the SCDS programmers in the integration phase

J-2 Engine ready to go into test stand

Science.gov (United States)

1965-01-01

Two technicians watch carefully as cables prepare to lift a J-2 engine into a test stand. The J-2 powered the second stage and the third stage of the Saturn V moon rocket. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Using GIFTS on the Cray-1 for the large coil test facility test: stand design analysis

International Nuclear Information System (INIS)

Baudry, T.V.; Gray, W.H.

1981-06-01

The GIFTS finite element program has been used extensively throughout the Large Coil Test Facility (LCTF) test stand design analysis. Effective use has been made of GIFTS both as a preprocessor to other finite element programs and as a complete structural analysis package. The LCTF test stand design involved stress analysis ranging from simple textbook-type problems to very complicated three-dimensional structural problems. Two areas of the design analysis are discussed

Design and Calibration of an RF Actuator for Low-Level RF Systems

Science.gov (United States)

Geng, Zheqiao; Hong, Bo

2016-02-01

X-ray free electron laser (FEL) machines like the Linac Coherent Light Source (LCLS) at SLAC require high-quality electron beams to generate X-ray lasers for various experiments. Digital low-level RF (LLRF) systems are widely used to control the high-power RF klystrons to provide a highly stable RF field in accelerator structures for beam acceleration. Feedback and feedforward controllers are implemented in LLRF systems to stabilize or adjust the phase and amplitude of the RF field. To achieve the RF stability and the accuracy of the phase and amplitude adjustment, low-noise and highly linear RF actuators are required. Aiming for the upgrade of the S-band Linac at SLAC, an RF actuator is designed with an I/Qmodulator driven by two digital-to-analog converters (DAC) for the digital LLRF systems. A direct upconversion scheme is selected for RF actuation, and an on-line calibration algorithm is developed to compensate the RF reference leakage and the imbalance errors in the I/Q modulator, which may cause significant phase and amplitude actuation errors. This paper presents the requirements on the RF actuator, the design of the hardware, the calibration algorithm, and the implementation in firmware and software and the test results at LCLS.

Study on the RF power necessary to ignite plasma for the ICP test facility at HUST

Energy Technology Data Exchange (ETDEWEB)

Yue, Haikun [School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan (China); State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan (China); Li, Dong; Wang, Chenre; Li, Xiaofei; Chen, Dezhi; Liu, Kaifeng; Zhou, Chi; Pan, Ruimin [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan (China)

2015-10-15

An Radio-Frequency (RF) Inductively Coupled Plasma (ICP) ion source test facility has been successfully developed at Huazhong University of Science and Technology (HUST). As part of a study on hydrogen plasma, the influence of three main operation parameters on the RF power necessary to ignite plasma was investigated. At 6 Pa, the RF power necessary to ignite plasma influenced little by the filament heating current from 5 A to 9 A. The RF power necessary to ignite plasma increased rapidly with the operation pressure decreasing from 8 Pa to 4 Pa. The RF power necessary to ignite plasma decreased with the number of coil turns from 6 to 10. During the experiments, plasma was produced with the electron density of the order of 10{sup 16}m{sup -3} and the electron temperature of around 4 eV. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Stand development and reliability tests of the thermal monitoring means for NPP

International Nuclear Information System (INIS)

Nalivaev, V.I.; Nikul'shin, V.S.; Kichigin, A.B.; Dirin, V.F.

2003-01-01

The paper is devoted to the reliability tests of thermoelectric thermometers and resistance thermometers during their operation in the nominal mode. Five stands Reliability are developed and operate for realization of tests of all manufactured thermal converters. delivered at NPP. Description of all stands are presented [ru

"Chair Stand Test" as Simple Tool for Sarcopenia Screening in Elderly Women.

Science.gov (United States)

Pinheiro, P A; Carneiro, J A O; Coqueiro, R S; Pereira, R; Fernandes, M H

2016-01-01

To investigate the association between sarcopenia and "chair stand test" performance, and evaluate this test as a screening tool for sarcopenia in community-dwelling elderly women. Cross-sectional Survey. 173 female individuals, aged ≥ 60 years and living in the urban area of the municipality of Lafaiete Coutinho, Bahia's inland, Brazil. The association between sarcopenia (defined by muscle mass, strength and/or performance loss) and performance in the "chair stand test" was tested by binary logistic regression technique. The ROC curve parameters were used to evaluate the diagnostic power of the test in sarcopenia screening. The significance level was set at 5 %. The model showed that the time spent for the "chair stand test" was positively associated (OR = 1.08; 95% CI = 1.01 - 1.16, p = 0.024) to sarcopenia, indicating that, for each 1 second increment in the test performance, the sarcopenia's probability increased by 8% in elderly women. The cut-off point that showed the best balance between sensitivity and specificity was 13 seconds. The performance of "chair stand test" showed predictive ability for sarcopenia, being an effective and simple screening tool for sarcopenia in elderly women. This test could be used for screening sarcopenic elderly women, allowing early interventions.

RF feedback for KEKB

Energy Technology Data Exchange (ETDEWEB)

Ezura, Eizi; Yoshimoto, Shin-ichi; Akai, Kazunori [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1996-08-01

This paper describes the present status of the RF feedback development for the KEK B-Factory (KEKB). A preliminary experiment concerning the RF feedback using a parallel comb-filter was performed through a choke-mode cavity and a klystron. The RF feedback has been tested using the beam of the TRISTAN Main Ring, and has proved to be effective in damping the beam instability. (author)

Independent validation of the MMPI-2-RF Somatic/Cognitive and Validity scales in TBI Litigants tested for effort.

Science.gov (United States)

Youngjohn, James R; Wershba, Rebecca; Stevenson, Matthew; Sturgeon, John; Thomas, Michael L

2011-04-01

The MMPI-2 Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008) is replacing the MMPI-2 as the most widely used personality test in neuropsychological assessment, but additional validation studies are needed. Our study examines MMPI-2-RF Validity scales and the newly created Somatic/Cognitive scales in a recently reported sample of 82 traumatic brain injury (TBI) litigants who either passed or failed effort tests (Thomas & Youngjohn, 2009). The restructured Validity scales FBS-r (restructured symptom validity), F-r (restructured infrequent responses), and the newly created Fs (infrequent somatic responses) were not significant predictors of TBI severity. FBS-r was significantly related to passing or failing effort tests, and Fs and F-r showed non-significant trends in the same direction. Elevations on the Somatic/Cognitive scales profile (MLS-malaise, GIC-gastrointestinal complaints, HPC-head pain complaints, NUC-neurological complaints, and COG-cognitive complaints) were significant predictors of effort test failure. Additionally, HPC had the anticipated paradoxical inverse relationship with head injury severity. The Somatic/Cognitive scales as a group were better predictors of effort test failure than the RF Validity scales, which was an unexpected finding. MLS arose as the single best predictor of effort test failure of all RF Validity and Somatic/Cognitive scales. Item overlap analysis revealed that all MLS items are included in the original MMPI-2 Hy scale, making MLS essentially a subscale of Hy. This study validates the MMPI-2-RF as an effective tool for use in neuropsychological assessment of TBI litigants.

Developments on the RF system for the Fusion Materials Irradiation Test Facility accelerator

International Nuclear Information System (INIS)

Fazio, M.V.; Johnson, H.P.; Riggin, D.M.

1979-01-01

The rf system for the Fusion Materials Irradiation Test (FMIT) accelerator is currently in the design phase at the Los Alamos Scientific Laboratory (LASL). The 35-MeV, 100-mA deuteron beam will require approximately 6 MW of rf power at 80 MHz. The EIMAC 8973 power tetrode, capable of a 600-kW cw output, has been chosen as the final amplifier tube for each of 15 amplifier chains. The final power stage of each chain is designed to perform as a linear Class B amplifier. Each low-power rf system (less than or equal to 100W) is to be phase, amplitude, and frequency controlled to provide a drive signal for each high-power amplifier. Beam dynamics for particle acceleration and for minimal beam spill require each rf amplifier output to be phase controlled to +-1 0 . The amplitude of the accelerating field must be held to +-1%. A varactor-tuned electronic phase shifter and a linear phase detector are under development for use in this system. To complement hardware development, analog computer simulations are being performed to optimize the closed-loop control characteristics of the system

Integration of the PHIN RF Gun into the CLIC Test Facility

CERN Document Server

Döbert, Steffen

2006-01-01

CERN is a collaborator within the European PHIN project, a joint research activity for Photo injectors within the CARE program. A deliverable of this project is an rf Gun equipped with high quantum efficiency Cs2Te cathodes and a laser to produce the nominal beam for the CLIC Test Facility (CTF3). The nominal beam for CTF3 has an average current of 3.5 A, 1.5 GHz bunch repetition frequency and a pulse length of 1.5 ìs (2332 bunches) with quite tight stability requirements. In addition a phase shift of 180 deg is needed after each train of 140 ns for the special CLIC combination scheme. This rf Gun will be tested at CERN in fall 2006 and shall be integrated as a new injector into the CTF3 linac, replacing the existing injector consisting of a thermionic gun and a subharmonic bunching system. The paper studies the optimal integration into the machine trying to optimize transverse and longitudinal phase space of the beam while respecting the numerous constraints of the existing accelerator. The presented scheme...

Measurement properties and feasibility of clinical tests to assess sit-to-stand/stand-to-sit tasks in subjects with neurological disease: a systematic review

Directory of Open Access Journals (Sweden)

Paula F. S. Silva

2014-04-01

Full Text Available BACKGROUND: Subjects with neurological disease (ND usually show impaired performance during sit-to-stand and stand-to-sit tasks, with a consequent reduction in their mobility levels. OBJECTIVE: To determine the measurement properties and feasibility previously investigated for clinical tests that evaluate sit-to-stand and stand-to-sit in subjects with ND. METHOD: A systematic literature review following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses protocol was performed. Systematic literature searches of databases (MEDLINE/SCIELO/LILACS/PEDro were performed to identify relevant studies. In all studies, the following inclusion criteria were assessed: investigation of any measurement property or the feasibility of clinical tests that evaluate sit-to-stand and stand-to-sit tasks in subjects with ND published in any language through December 2012. The COSMIN checklist was used to evaluate the methodological quality of the included studies. RESULTS: Eleven studies were included. The measurement properties/feasibility were most commonly investigated for the five-repetition sit-to-stand test, which showed good test-retest reliability (Intraclass Correlation Coefficient:ICC=0.94-0.99 for subjects with stroke, cerebral palsy and dementia. The ICC values were higher for this test than for the number of repetitions in the 30-s test. The five-repetition sit-to-stand test also showed good inter/intra-rater reliabilities (ICC=0.97-0.99 for stroke and inter-rater reliability (ICC=0.99 for subjects with Parkinson disease and incomplete spinal cord injury. For this test, the criterion-related validity for subjects with stroke, cerebral palsy and incomplete spinal cord injury was, in general, moderate (correlation=0.40-0.77, and the feasibility and safety were good for subjects with Alzheimer's disease. CONCLUSIONS: The five-repetition sit-to-stand test was used more often in subjects with ND, and most of the measurement

RF Tests of an 805 MHz Pillbox Cavity at Lab G of Fermilab

International Nuclear Information System (INIS)

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

2003-01-01

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

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

International Nuclear Information System (INIS)

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

2003-01-01

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

First cold test of TESLA superconducting RF cavity in horizontal cryostat (CHECHIA)

International Nuclear Information System (INIS)

Kuzminski, J.

1996-01-01

In the framework of the TESLA project, the horizontal cryostat (CHECHIA) was built to test a superconducting RF cavity equipped with its helium vessel, magnetic shielding, cold tuner, main coupler and higher order modes couplers under realistic conditions before final assembly of eight cavities into TESLA Test Facility cryo-module. The results of the first cold tests in CHECHIA, performed at DESY with a 9-cell cavity (C19) to be used in the TTF injector are presented. (author)

Trends in RF-structure research

International Nuclear Information System (INIS)

Henke, H.

1995-01-01

New trends in RF structure research are presented. The choice is limited to developments as they are required by the next generation of light sources, particle factories and linear colliders. Therefore, emphasis is put on the suppression of higher order modes either in standing or travelling wave resonators and on the development of superconducting cavities. Finally, a brand new development of very high frequency structures with planar geometry suited for fabrication by lithography is mentioned. copyright 1995 American Institute of Physics

Fluxon interaction with external rf radiation in Josephson junctions

DEFF Research Database (Denmark)

Kivshar, Yuri S.; Olsen, Ole H.; Samuelsen, Mogens Rugholm

1993-01-01

. It is shown that due to excitation of a standing linear wave by the driving force, the fluxon motion is strongly influenced by a periodic (averaged) potential similar to the Peierls-Nabarro potential in a discrete chain. This effective potential decreases in the direction of the boundary where the external rf...

Fabrication and tests and RF control of the superconducting resonators of the Saclay heavy ion LINAC

International Nuclear Information System (INIS)

Cauvin, B.; Coret, M.; Fouan, J.P.; Girard, J.; Girma, J.L.; Leconte, P.; Lussignol, Y.; Moreau, R.; Passerieux, J.P.; Ramstein, G.; Wartski, L.

1987-01-01

Two types of niobium superconducting resonators used in the Saclay linac are discussed. The outer cylinder and RF ports are identical for the two designs, but internal structures are different: full wave helix with three gaps behavior; or half wave with two gaps behavior. All cavities (34 full wave, 16 half) were tested for field and mounted in the machine cryostats. Cavity fabrication and performance are summarized. Vibration tests and Rf control are described. It is argued that helix resonators can overcome problems due to vibration. The very low lock out time percentage measured in an acceleration test with 21 cavities supports this confidence

The stand-alone test and decreasing serial cost sharing

DEFF Research Database (Denmark)

Hougaard, Jens Leth; Thorlund-Petersen, Lars

2000-01-01

The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability...

Mobile test stand for evaluation of electric power plants for unmanned aircraft

Directory of Open Access Journals (Sweden)

Serbezov Vladimir

2017-01-01

Full Text Available The absence of accurate performance data is a common problem with most civilian unmanned aerial vehicle (UAV power plant producers. The reasons for this are the small size of most of the manufacturers and the high price of precise wind tunnel testing and computer simulations. To overcome this problem at Dronamics Ltd., with support from the Department of Aeronautics of TU-Sofia, a mobile test stand for evaluation of electric power plants for unmanned aircraft was developed. The stand may be used statically, or may be installed on the roof of an automobile. The measurement system of the stand is based on popular hardware that is used in radio controlled models and in general automation. The verification of the measurement system is performed by comparing static test results with data published by the manufacturer of the tested electric motor. Tests were carried out with 2 different types of propellers and the results were compared with published results for common propellers as well as with results of theoretical studies. The results are satisfactory for practical applications. The use of this type of test stands can be a cheap and effective alternative for research and development start-up companies like Dronamics.

Electron beam characterization of a combined diode rf electron gun

Directory of Open Access Journals (Sweden)

R. Ganter

2010-09-01

Full Text Available Experimental and simulation results of an electron gun test facility, based on pulsed diode acceleration followed by a two-cell rf cavity at 1.5 GHz, are presented here. The main features of this diode-rf combination are: a high peak gradient in the diode (up to 100  MV/m obtained without breakdown conditioning, a cathode shape providing an electrostatic focusing, and an in-vacuum pulsed solenoid to focus the electron beam between the diode and the rf cavity. Although the test stand was initially developed for testing field emitter arrays cathodes, it became also interesting to explore the limits of this electron gun with metallic photocathodes illuminated by laser pulses. The ultimate goal of this test facility is to fulfill the requirements of the SwissFEL project of Paul Scherrer Institute [B. D. Patterson et al., New J. Phys. 12, 035012 (2010NJOPFM1367-263010.1088/1367-2630/12/3/035012]; a projected normalized emittance below 0.4  μm for a charge of 200 pC and a bunch length of less than 10 ps (rms. A normalized projected emittance of 0.23  μm with 13 pC has been measured at 5 MeV using a Gaussian laser longitudinal intensity distribution on the photocathode. Good agreements with simulations have been obtained for different electron bunch charge and diode geometries. Emittance measurements at a bunch charge below 1 pC were performed for different laser spot sizes in agreement with intrinsic emittance theory [e.g. 0.54  μm/mm of laser spot size (rms for Cu at 274 nm]. Finally, a projected emittance of 1.25+/-0.2  μm was measured with 200 pC and 100  MV/m diode gradient.

Pilot Field Test: Use of a Compression Garment During a Stand Test After Long-Duration Space Flight

Science.gov (United States)

Laurie, S. S.; Stenger, M. B.; Phillips, T. R.; Lee, S. M. C.; Cerisano, J.; Kofman, I.; Reschke, M.

2016-01-01

Orthostatic intolerance (OI) is a concern for astronauts returning from long-duration space flight. One countermeasure that has been used to protect against OI after short-duration bed rest and space flight is the use of lower body and abdominal compression garments. However, since the end of the Space Shuttle era we have not been able to test crewmembers during the first 24 hours after landing on Earth. NASA's Pilot Field Test provided us the opportunity to test cardiovascular responses of crewmembers wearing the Russian Kentavr compression garment during a stand test at multiple time points throughout the first 24 hours after landing. HYPOTHESIS We hypothesized that the Kentavr compression garment would prevent an increase in heart rate (HR) >15 bpm during a 3.5-min stand test. METHODS: The Pilot Field Test was conducted up to 3 times during the first 24 hours after crewmembers returned to Earth: (1) either in a tent adjacent to the Soyuz landing site in Kazakhstan (approx.1 hr) or after transportation to the Karaganda airport (approx. 4 hr); (2) during a refueling stop in Scotland (approx.12 hr); and (3) upon return to NASA Johnson Space Center (JSC) (approx.24 hr). We measured HR and arterial pressure (finger photoplethysmography) for 2 min while the crewmember was prone and throughout 3.5 min of quiet standing. Eleven crewmembers consented to participate; however, 2 felt too ill to start the test and 1 stopped 30 sec into the stand portion of the test. Of the remaining 8 crewmembers, 2 did not wear the Russian Kentavr compression garment. Because of inclement weather at the landing site, 5 crewmembers were flown by helicopter to the Karaganda airport before initial testing and received intravenous saline before completing the stand test. One of these crewmembers wore only the portion of the Russian Kentavr compression garment that covered the lower leg and thus lacked thigh and abdominal compression. All crewmembers continued wearing the Russian Kentavr

Optimisation of the test policy of stand-by systems

International Nuclear Information System (INIS)

Signoret, J.P.; Muron, O.; Cohen, G.

1980-09-01

In a nuclear power plant there are several systems which are on stand-by position as, for instance, safety systems. These stand-by systems have to be ready to start as soon as any situation for which they have be designed occurs. A test policy is then necessary in order to know the state of such a system and repair the possible failures. The tests are normally performed at regular intervals of time according to a scheduled sequence. We have already shown during the 'IIIeme Congres National de Fiabilite' held in Perros-Guirec in 1976 how it is possible in this case to find the optimum test interval leading to the best mean availability of the system. It is, in fact, possible, to improve that by considering that if the test interval is fixed 'a priori' this does not allow to take into account information we have on the system state every time [fr

Practical test of the LINAC4 RF power system

CERN Document Server

Schwerg, N

2011-01-01

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 klystrons of 2.8 MW all operating at a frequency of 352.2 MHz. The power distribution scheme features a folded magic tee feeding the power from one 2.8 MW klystron to two LEP circulators. We present first results from the Linac4 test place, validating the approach and the used components as well as reporting on the klystron re-tuning activities.

The RF Probe: providing space situational awareness through broad-spectrum detection and characterization

Science.gov (United States)

Zenick, Raymond; Kohlhepp, Kimberly; Partch, Russell

2004-09-01

AeroAstro's patented RF Probe is a system designed to address the needs of spacecraft developers and operators interested in measuring and analyzing near-field RF emissions emanating from a nearby spacecraft of interest. The RF Probe consists of an intelligent spectrum analyzer with digital signal processing capabilities combined with a calibrated, wide-bandwidth antenna and RF front end that covers the 50 kHz to 18 GHz spectrum. It is capable of acquiring signal level and signal vector information, classifying signals, assessing the quality of a satellite"s transponders, and characterizing near-field electromagnetic emissions. The RF Probe is intended for either incorporation as part of a suite of spacecraft sensors, or as a stand-alone sensor on spacecraft or other platforms such as Unmanned Aerial Vehicles (UAVs). The RF Probe was initially conceived as a tool to detect and aid in diagnosis of malfunctions in a spacecraft of interest. However, the utility of the RF Probe goes far beyond this initial concept, spanning a wide range of military applications. Most importantly, the RF Probe can provide space situational awareness for critical on-orbit assets by detecting externally induced RF fields, aiding in protection against potentially devastating attacks.

Hip Strength Testing of Soccer Players With Long-Standing Hip and Groin Pain

DEFF Research Database (Denmark)

Rafn, Bolette S; Tang, Lars; Nielsen, Peter Martin

2016-01-01

OBJECTIVE: To investigate whether self-reported pain during hip strength testing correlates to a large degree with hip muscle strength in soccer players with long-standing unilateral hip and groin pain. DESIGN: Cross-sectional study. SETTING: Clinical assessments at Sports Orthopaedic Research...... Center-Copenhagen (SORC-C), Arthroscopic Centre Amager, Copenhagen University Hospital, Denmark. PARTICIPANTS: Twenty-four male soccer players with unilateral long-standing hip and groin pain. INTERVENTIONS: The soccer players performed 5 reliable hip muscle strength tests (isometric hip flexion...... strength (Spearman rho = -0.44, P = 0.016). CONCLUSIONS: Self-reported pain during testing does not seem to correlate with the majority of hip muscle strength tests used in soccer players with long-standing hip and groin pain....

National RF Test Facility as a multipurpose development tool

International Nuclear Information System (INIS)

McManamy, T.J.; Becraft, W.R.; Berry, L.A.

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

Development of high power CW and pulsed RF test facility based on 1 MW, 352.2 MHz klystron amplifier

International Nuclear Information System (INIS)

Badapanda, M.K.; Tripathi, Akhilesh; Upadhyay, Rinki; Rao, J.N.; Tiwari, Ashish; Jain, Akhilesh; Lad, M.R.; Hannurkar, P.R.

2013-01-01

A high power 1 MW, 352.2 MHz RF Test facility having CW and Pulse capability is being developed at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore for performance evaluation of various RF components, accelerating structures and related subsystems. Thales make 1 MW, 352.2 MHz klystron amplifier (TH 2089) will be employed in this high power test facility, which is thoroughly tested for its performance parameters at rated operating conditions. Auxiliary power supplies like filament, electromagnet, ion pump and mod anode power supply as well as 200 W solid state driver amplifier necessary for this high power test facility have been developed. A high voltage floating platform is created for floating filament and mod anode power supplies. Interconnection of various power supplies and other subsystems of this test facility are being carried out. A high voltage 100 kV, 25 Amp DC crowbar less power supply and low conductivity water (LCW) plant required for this klystron amplifier are in advanced stage of development. NI make cRIO 9081 real time (RT) controller based control and interlock system has been developed to realize proper sequence of operation of various power supplies and to monitor the status of crucial parameters in this test facility. This RF test facility will provide confidence for development of RF System of future accelerators like SNS and ADSS. (author)

Measured performance of the GTA rf systems

International Nuclear Information System (INIS)

Denney, P.M.; Jachim, S.P.

1993-01-01

This paper describes the performance of the RF systems on the Ground Test Accelerator (GTA). The RF system architecture is briefly described. Among the RF performance results presented are RF field flatness and stability, amplitude and phase control resolution, and control system bandwidth and stability. The rejection by the RF systems of beam-induced disturbances, such as transients and noise, are analyzed. The observed responses are also compared to computer-based simulations of the RF systems for validation

Design and RF test result of High Power Hybrid Combiner for Helicon Wave Current Drive in KSTAR Plasmas

Energy Technology Data Exchange (ETDEWEB)

Park, S. Y.; Kim, H. J.; Wi, H. H.; Wang, S. J.; Kwak, J. G. [NFRI, Daejeon (Korea, Republic of)

2016-05-15

200 kW RF power will be injected to plasmas through the traveling wave antenna after combining four klystrons output powers using three hybrid combiners. Each klystron produces 60 kW output at the frequency of 500 MHz. RF power combiners commonly used to divide or combine output powers for various rf and microwave applications. It is divided into several types according to the design type such as Wilkinson combiner, radial and quadrature hybrid combiner. We designed high power hybrid combiners using 6-1/8 inch coaxial line. The power combiner has many advantages such as high isolation, low insertion loss and high power handling capability. In this paper design and rf test results of high power combiners will be described. High power combiners using three coaxial hybrid couplers will be utilized for effectively combining of 500 MHz, 200 kW output powers generated by four klystrons. We have designed, fabricated, and tested a 6-1/8 inch coaxial hybrid combiners at 500 MHz for efficiently off-axis Helicon wave current drive in KSTAR. Simulation and test results of high power coaxial hybrid combiners are good agreement.

Micromachined sensor for stress measurement and micromechanical study of free-standing thin films for MEMS applications

Science.gov (United States)

Zhang, Ping

Microelectromechanical systems (MEMS) have a wide range of applications. In the field of wireless and microwave technology, considerable attention has been given to the development and integration of MEMS-based RF (radio frequency) components. An RF MEMS switch requires low insertion loss, high isolation, and low actuation voltage - electrical aspects that have been extensively studied. The mechanical requirements of the switch, such as low sensitivity to built-in stress and high reliability, greatly depend on the micromechanical properties of the switch materials, and have not been thoroughly explored. RF MEMS switches are typically in the form of a free-standing thin film structure. Large stress gradients and across-wafer stress variations developed during fabrication severely degrade their electrical performance. A micromachined stress measurement sensor has been developed that can potentially be employed for in-situ monitoring of stress evolution and stress variation. The sensors were micromachined using five masks on two wafer levels, each measuring 5x3x1 mm. They function by means of an electron tunneling mechanism, where a 2x2 mm silicon nitride membrane elastically deflects under an applied deflection voltage via an external feedback circuitry. For the current design, the sensors are capable of measuring tensile stresses up to the GPa range under deflection voltages of 50--100 V. Sensor functionality was studied by finite element modeling and a theoretical analysis of square membrane deflection. While the mechanical properties of thin films on substrates have been extensively studied, studies of free-standing thin films have been limited due to the practical difficulties in sample handling and testing. Free-standing Al and Al-Ti thin films specimens have been successfully fabricated and microtensile and stress relaxation tests have been performed using a custom-designed micromechanical testing apparatus. A dedicated TEM (transmission electron microscopy

Testing Procedures and Results of the Prototype Fundamental Power Coupler for the Spallation Neutron Source

International Nuclear Information System (INIS)

M. Stirbet; I.E. Campisi; E.F. Daly; G.K. Davis; M. Drury; P. Kneisel; G. Myneni; T. Powers; W.J. Schneider; K.M. Wilson; Y. Kang; K.A. Cummings; T. Hardek

2001-01-01

High-power RF testing with peak power in excess of 500 kW has been performed on prototype Fundamental Power Couplers (FPC) for the Spallation Neutron Source superconducting (SNS) cavities. The testing followed the development of procedures for cleaning, assembling and preparing the FPC for installation in the test stand. The qualification of the couplers has occurred for the time being only in a limited set of conditions (travelling wave, 20 pps) as the available RF system and control instrumentation are under improvement

rf traveling-wave electron gun for photoinjectors

Science.gov (United States)

Schaer, Mattia; Citterio, Alessandro; Craievich, Paolo; Reiche, Sven; Stingelin, Lukas; Zennaro, Riccardo

2016-07-01

The design of a photoinjector, in particular that of the electron source, is of central importance for free electron laser (FEL) machines where a high beam brightness is required. In comparison to standard designs, an rf traveling-wave photocathode gun can provide a more rigid beam with a higher brightness and a shorter pulse. This is illustrated by applying a specific optimization procedure to the SwissFEL photoinjector, for which a brightness improvement up to a factor 3 could be achieved together with a double gun output energy compared to the reference setup foreseeing a state-of-the-art S-band rf standing-wave gun. The higher brightness is mainly given by a (at least) double peak current at the exit of the gun which brings benefits for both the beam dynamics in the linac and the efficiency of the FEL process. The gun design foresees an innovative coaxial rf coupling at both ends of the structure which allows a solenoid with integrated bucking coil to be placed around the cathode in order to provide the necessary focusing right after emission.

Effects of rf breakdown on the beam in the Compact Linear Collider prototype accelerator structure

Directory of Open Access Journals (Sweden)

A. Palaia

2013-08-01

Full Text Available Understanding the effects of rf breakdown in high-gradient accelerator structures on the accelerated beam is an extremely relevant aspect in the development of the Compact Linear Collider (CLIC and is one of the main issues addressed at the Two-beam Test Stand at the CLIC Test Facility 3 at CERN. During a rf breakdown high currents are generated causing parasitic magnetic fields that interact with the accelerated beam affecting its orbit. The beam energy is also affected because the power is partly reflected and partly absorbed thus reducing the available energy to accelerate the beam. We discuss here measurements of such effects observed on an electron beam accelerated in a CLIC prototype structure. Measurements of the trajectory of bunch trains on a nanosecond time scale showed fast changes in correspondence of breakdown that we compare with measurements of the relative beam spots on a scintillating screen. We identify different breakdown scenarios for which we offer an explanation based also on measurements of the power at the input and output ports of the accelerator structure. Finally we present the distribution of the magnitude of the observed changes in the beam position and we discuss its correlation with rf power and breakdown location in the accelerator structure.

Design development and testing of high voltage power supply with crowbar protection for IOT based RF amplifier system in VECC

Science.gov (United States)

Thakur, S. K.; Kumar, Y.

2018-05-01

This paper described the detailed design, development and testing of high voltage power supply (‑30 kV, 3.2 A) and different power supplies for biasing electrodes of Inductive Output Tube (IOT) based high power Radio Frequency (RF) amplifier. This IOT based RF amplifier is further used for pursuing research and development activity in superconducting RF cavity project at Variable Energy Cyclotron Centre (VECC) Kolkata. The state-of-the-art technology of IOT-based high power RF amplifier is designed, developed, and tested at VECC which is the first of its kind in India. A high voltage power supply rated at negative polarity of 30 kV dc/3.2 A is required for biasing cathode of IOT with crowbar protection circuit. This power supply along with crowbar protection system is designed, developed and tested at VECC for testing the complete setup. The technical difficulties and challenges occured during the design of cathode power supply, its crowbar protection techniques along with other supported power supplies i.e. grid and ion pump power supplies are discussed in this paper.

Construction, commissioning and initial operation of 2400W refrigerator and cold test stand for CDM testing

International Nuclear Information System (INIS)

Dubbs, J.D.; Kreinbrink, K.

1994-01-01

Air Products and CVI collaborated to design, construct and commission a refrigerator, test stands and integrated control system for the General Dynamics Collider Dipole Magnet Cold Test Facility (CTF) in Hammond, LA. The original project schedule required the cold test facility to be operational within 17 months of the notice to proceed. Midway through the project, changes in General Dynamics magnet testing requirements necessitated doubling the plant capacity, but the on stream date for the initial capacity increment could not be relaxed. The Air Products/CVI team had to adapt the project execution strategy to mitigate the schedule impact of the expansion in a cost effective manner without impacting system functionality, quality or safety. An equally challenging aspect of the job was that the (CTF) was being designed while several major systems that would interface with the CTF were being engineered. General Dynamics, Air Products and CVI had to work very closely to manage the interface issues. The teams efforts were very successful. The Hammond refrigerator/liquifier was started up on schedule. The first two test stands are currently being commissioned and will be on stream just six weeks later than the pre-expansion schedule target and all four test stands will be operational in time to support General Dynamics magnet testing requirements

Development of the rf linear accelerator test bed for heavy-ion fusion

International Nuclear Information System (INIS)

Watson, J.M.

1981-01-01

The amount of absorbed energy required by high gain deuterium-tritium targets for inertial confinement fusion reactors is now projected to be greater than 1 Megajoule. It has become apparent that a heavy ion fusion driver is the preferred choice in this scenario. To demonstrate this accelerator-based option, the national program has established two test beds: one at Argonne for the rf linac/storage ring approach, and one at Lawrence Berkeley Laboratory developing an induction linac. The Argonne Beam Development Facility (BDF) would consist of a 40 mA rf linac for Xe + 8 , a storage ring, and a 10 GeV synchrotron. The design and status of the BDF is described as well as future program options to demonstrate as many solutions as possible of the issues involved in this approach

Beam dynamics simulations in the photo-cathode RF gun for the CLIC test facility

International Nuclear Information System (INIS)

Marchand, P.; Rinolfi, L.

1992-01-01

The CERN CLIC Test Facility (CTF) uses an RF gun with a laser driven photo-cathode in order to generate electron pulses of high charge (≥10 nC) and short duration (≤20 ps). The RF gun consists of a 3 GHz 1 + 1/2 cell cavity based on the design originally proposed at BNL which minimizes the non-linearities in the transverse field. The beam dynamics in the cavity is simulated by means of the multiparticle tracking code PARMELA. The results are compared to previous simulations as well as to the first experimental data. (author). 4 refs., 4 tabs., 4 figs

Impedance matching of pillbox-type RF windows and direct measurement of the ceramic relative dielectric constant

Energy Technology Data Exchange (ETDEWEB)

Ao, Hiroyuki, E-mail: hiroyuki.ao@j-parc.jp [Japan Atomic Energy Agency (JAEA), J-PARC Center, Accelerator Division, 2-4, Shirakara Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Asano, Hiroyuki [Japan Atomic Energy Agency (JAEA), J-PARC Center, Accelerator Division, 2-4, Shirakara Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Naito, Fujio [High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba, Ibaraki 305-0801 (Japan); Ouchi, Nobuo; Tamura, Jun [Japan Atomic Energy Agency (JAEA), J-PARC Center, Accelerator Division, 2-4, Shirakara Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan); Takata, Koji [High Energy Accelerator Research Organization (KEK), 1-1, Oho, Tsukuba, Ibaraki 305-0801 (Japan)

2014-02-11

Impedance matching of RF windows that minimizes the RF reflection is necessary to prevent localized standing waves between an RF window and a cavity, which may cause thermal and/or multipactoring issues. It has been observed that the impedance matching condition of the pillbox-type RF window, checked by voltage standing wave ratio (VSWR) measurement, depends on the manufacturing lot of the window ceramic disk made of 95% purity Al{sub 2}O{sub 3}. The present report proposes new procedures for impedance matching as follows: (i) The relative dielectric constant of the ceramic window is directly measured using the resonant frequency of a cavity made by temporarily combining the pillbox part of the RF window and two short-circuiting plates. (ii) The dimensions of the pillbox section including the ceramic disk are fixed on the basis of the measured relative dielectric constant. To confirm this procedure, three RF windows were fabricated using the same type of ceramic material, and successful impedance matching of these windows was performed (VSWR<1.05). The measured results also suggest that the relative dielectric constant increases linearly with increasing density and that the impedance matching condition is mainly affected by variations of the relative dielectric constant due to shrinkage of the alumina during sintering. -- Highlights: • We measured the relative dielectric constant of an RF window ceramic directly. • We used the circular TE011-mode frequency of the pillbox part of an RF window itself. • The dimensions of the pillbox part were fixed on the basis of the measurement result. • Three RF windows were fabricated, and VSWR <1.05 for these windows was performed. • The relative dielectric constant increases linearly with increasing ceramic density.

Impedance matching of pillbox-type RF windows and direct measurement of the ceramic relative dielectric constant

International Nuclear Information System (INIS)

Ao, Hiroyuki; Asano, Hiroyuki; Naito, Fujio; Ouchi, Nobuo; Tamura, Jun; Takata, Koji

2014-01-01

Impedance matching of RF windows that minimizes the RF reflection is necessary to prevent localized standing waves between an RF window and a cavity, which may cause thermal and/or multipactoring issues. It has been observed that the impedance matching condition of the pillbox-type RF window, checked by voltage standing wave ratio (VSWR) measurement, depends on the manufacturing lot of the window ceramic disk made of 95% purity Al 2 O 3 . The present report proposes new procedures for impedance matching as follows: (i) The relative dielectric constant of the ceramic window is directly measured using the resonant frequency of a cavity made by temporarily combining the pillbox part of the RF window and two short-circuiting plates. (ii) The dimensions of the pillbox section including the ceramic disk are fixed on the basis of the measured relative dielectric constant. To confirm this procedure, three RF windows were fabricated using the same type of ceramic material, and successful impedance matching of these windows was performed (VSWR<1.05). The measured results also suggest that the relative dielectric constant increases linearly with increasing density and that the impedance matching condition is mainly affected by variations of the relative dielectric constant due to shrinkage of the alumina during sintering. -- Highlights: • We measured the relative dielectric constant of an RF window ceramic directly. • We used the circular TE011-mode frequency of the pillbox part of an RF window itself. • The dimensions of the pillbox part were fixed on the basis of the measurement result. • Three RF windows were fabricated, and VSWR <1.05 for these windows was performed. • The relative dielectric constant increases linearly with increasing ceramic density

Large source test stand for H-(D-) ion source

International Nuclear Information System (INIS)

Larson, R.; McKenzie-Wilson, R.

1981-01-01

The Brookhaven National Laboratory Neutral Beam Group has constructed a large source test stand for testing of the various source modules under development. The first objective of the BNL program is to develop a source module capable of delivering 10A of H - (D - ) at 25 kV operating in the steady state mode with satisfactory gas and power efficiency. The large source test stand contains gas supply and vacuum pumping systems, source cooling systems, magnet power supplies and magnet cooling systems, two arc power supplies rated at 25 kW and 50 kW, a large battery driven power supply and an extractor electrode power supply. Figure 1 is a front view of the vacuum vessel showing the control racks with the 36'' vacuum valves and refrigerated baffles mounted behind. Figure 2 shows the rear view of the vessel with a BNL Mk V magnetron source mounted in the source aperture and also shows the cooled magnet coils. Currently two types of sources are under test: a large magnetron source and a hollow cathode discharge source

RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

Energy Technology Data Exchange (ETDEWEB)

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

Low frequency rf current drive

International Nuclear Information System (INIS)

Hershkowitz, N.

1992-01-01

An unshielded antenna for rf heating has been developed and tested during this report period. In addition to design specifications being given, some experimental results are presented utilizing: (1) an unprotected Faraday shield, (2) insulating guard limiters, (3) unshielded antenna experiments, (4) method for detecting small rf driven currents, (5) rf fast wave current drive experiments, (6) alfven wave interactions with electrons, and (7) machine conditioning, impurity generation and density control

F-15B ACTIVE test stand

Science.gov (United States)

1995-01-01

This November 13, 1995, photograph of the underside of the F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) at NASA's Dryden Flight Research Center, Edwards, California, shows the thrust stand being used for ground testing of a new thrust-vectoring concept. The twin-engine F-15 research aircraft is equipped with new Pratt & Whitney nozzles that can turn up to 20 degrees in any direction. They give the aircraft thrust control in the pitch (up and down) and yaw (left and right) directions. This will reduce drag and increase fuel economy or range as compared with conventional aerodynamic controls, which increase the retarding forces (drag) acting upon the aircraft. Ground testing during the first two weeks of November 1995 went well, and flight tests began in March 1996. These tests could result in significant performance increases for military and commercial aircraft. The research program is the product of a collaborative effort by NASA, the Air Force's Wright Laboratory, Pratt & Whitney, and McDonnell Douglas Aerospace.

High RF power test of a CFC antenna module for lower hybrid current drive

International Nuclear Information System (INIS)

Maebara, S.; Seki, M.; Ikeda, Y.; Kiyono, K.; Suganuma, K.; Imai, T.; Goniche, M.; Bibet, Ph.; Brossaud, J.; Cano, V.; Kazarian-Vibert, F.; Froissard, P.; Rey, G.

1998-01-01

A mock-up of a 3.7 GHz Lower Hybrid Current Drive (LHCD) antenna module was fabricated from Carbon Fibre Composite (CFC) for the development of heat resistive low Z front facing the plasma. This 2 divided waveguide module is made from CFC plates and rods which are Cu-plated to reduce the RF losses. The withstand-voltage, the RF properties and the outgassing rates for long pulses and high RF power were tested at the Lower Hybrid test bed facility of Cadarache. A reference module made from Dispersion Strengthened Copper (DSC) was also fabricated. After the short pulse conditioning, long pulses with a power density ranging between 50 and 150 MW/m 2 were performed with no breakdowns on the CFC module. It was also checked that the highest power density, up to 150 MW/m 2 , could be transmitted when the waveguides are filled with H2 at a pressure of 5 x 10 -2 Pa. During a long pulse, the power reflection coefficient remains low in the 0.8-1.3 % range and no significant change in the reflection coefficient is measured after the thermal cycling provided by the long pulse operation. From thermocouple measurements, RF losses of the copper coated CFC and the DSC modules were compared. No significant differences were measured. From pressure measurements, it was found that the outgassing rate of Cu-plated CFC is about 6-7 times larger than of DSC at 300 deg.C. It is concluded that a CFC module is an attractive candidate for the hardening of the tip of the LHCD antenna. (author)

Review of pulsed rf power generation

International Nuclear Information System (INIS)

Lavine, T.L.

1992-04-01

I am going to talk about pulsed high-power rf generation for normal-conducting electron and positron linacs suitable for applications to high-energy physics in the Next Linear Collider, or NLC. The talk will cover some basic rf system design issues, klystrons and other microwave power sources, rf pulse-compression devices, and test facilities for system-integration studies

Reliability of Arm Curl and Chair Stand tests for assessing muscular endurance in older people

Directory of Open Access Journals (Sweden)

Boneth M

2012-05-01

Full Text Available Objective: to assess the test-retest reliability and level of agreement between measures of the 30 second (30-s Arm Curl and 30-s Chair Stand test in a sample of older adults from Bucaramanga. Materials and methods: a study of evaluation of diagnostic technology was done. Both tests were administered by the same evaluator to 111 adults older than 59 year-old (70,4 ± 7,3, on two occasions, with an interval of time between measures of 4 to 8 days. In the analysis, test-retest reliability was determined using the Intraclass Correlation Coefficient ICC= 2,1 with their confidence interval 95% (CI 95% respective. The agreement level was established by the Bland and Altman method. Results: the test-retest reproducibility of the 30-s Arm Curl test was very good ICC= 0,88 and to the Chair Stand test was good ICC= 0,78. The agreement was very good for both tests of muscle endurance. The CI 95% were between -3,8 and 3,2 stands to 30-s Chair Stand test and between -3,1 and 2,8 curls to 30-s Arm Curl test. Conclusion: the 30-s Arm Curl and 30-s Chair Stand test have good reliability and agreement to assess muscle endurance in older adults functionally independent.

Multi-cell disk-and-ring tapered structure for compact RF linacs

Energy Technology Data Exchange (ETDEWEB)

Smirnov, A.V.; Boucher, S.; Kutsaev, S. [RadiaBeam Systems LLC, 1713 Stewart Street, Santa Monica, CA 90404, US (United States); Hartzell, J. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); Savin, E. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

2016-09-11

A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

Multi-cell disk-and-ring tapered structure for compact RF linacs

International Nuclear Information System (INIS)

Smirnov, A.V.; Boucher, S.; Kutsaev, S.; Hartzell, J.; Savin, E.

2016-01-01

A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

Stand tests of the grader unit AKD-2

Energy Technology Data Exchange (ETDEWEB)

Kocheskhov, S.M.; Bagley, A.V.; Shalkov, A.V.

1982-01-01

Results are presented of stand tests of a static operating grader designed for unmanned extraction of deep beds with programmed control of the unit AKD-2 according to hypsometry of the seam occurrence. Malfunctions in a number of grader assemblies are revealed and eliminated. Parameters are defined which characterize the kinematics and dynamics of the grader mechanism.

Project of a test stand for cyclotron ion sources

International Nuclear Information System (INIS)

Buettig, H.; Dietrich, J.; Merker, H.; Odrich, H.; Preusche, S.; Weissig, J.

1978-10-01

In the work the construction of a test stand for testing and optimization of ion sources of the Rossendorf cyclotron U-120 is represented. The design procedure and the construction of the electromagnet, the vacuum chamber with monant, the vacuum system, the power supply and the detecting system are demonstrated. The results of calculations of the motion of ions in the magnetic field are presented. (author)

Commercialization of an S-band standing-wave electron accelerator for industrial applications

Science.gov (United States)

Moon, Jin-Hyeok; Kwak, Gyeong-Il; Han, Jae-Ik; Lee, Gyu-Baek; Jeon, Seong-Hwan; Kim, Jae-Young; Hwang, Cheol-Bin; Lee, Gi-Yong; Kim, Young-Man; Park, Sung-Ju

2016-09-01

An electron accelerator system has been developed for use in industrial, as well as possible medical, applications. Based on our experiences achieved during prototype system development and various electron beam acceleration tests, we have built a stable and compact system for sales purposes. We have integrated a self-developed accelerating cavity, an E-gun pulse driver, a radio-frequency (RF) power system, a vacuum system, a cooling system, etc. into a frame with a size of 1800 × 1000 × 1500 mm3. The accelerating structure is a side-coupled standing-wave type operating in the π/2 mode (tuned to~3 GHz). The RF power is provided by using a magnetron driven by a solid-state modulator. The electron gun is a triode type with a dispenser cathode (diameter of 11 mm). The system is capable of delivering a maximum 900-W average electron beam power with tight focusing at the target. Until now, we have performed various electron beam tests and X-ray beam tests after having built the system, have completed the beam assessment for commercializations, and have been preparing full-fledged sales activity. This article reports on our system development processes and on some of our early test results for commercializations.

Non-radioactive stand-in for radioactive contamination. I. Non-radioactive tests

International Nuclear Information System (INIS)

Rohe, M.J.; Rankin, W.N.; Postles, R.L.

1985-01-01

Candidate non-radioactive materials for use as a stand-in for radioactive contamination during application of a high-pressure, hot water decontamination were identified and evaluated. A stand-in for radioactive contamination is needed to evaluate the decontaminability of replacement canyon cranes at the manufacturers location where actual radioactive contamination cannot be used. This evaluation was conducted using high-pressure, hot-water at 420 psi, 190 0 F, and 20 gal/min through a 1/8-in.-diam nozzle, the decontamination technique preferred by SRP Separations Department for this application. A non-radioactive stand-in for radioactive contamination was desired that would be removed by direct blast stream contact but would remain intact on surfaces where direct contact does not occur. This memorandum describes identification of candidate non-radioactive stand-in materials and evaluation of these materials in screening tests and tests with high-pressure, hot-water blasting. The following non-radioactive materials were tested: carpenter's line chalk; typing correction fluid; dye penetrant developer; latex paint with attapulyite added; unaltered latex paint; gold enamel; layout fluid; and black enamel. Results show that blue layout fluid and gold enamel have similar adherence that is within the range expected for actual radioactive contamination. White latex paint has less adherence than expected for actual radioactive contamination. The film was removed at a rate of 2 . Black enamel has more adherence than expected from actual radioactive contamination. In these tests ASTM No. 2B surfaces were harder to clean than either ASTM No. 1 or electropolished surfaces which had similar cleaning properties. A 90 0 blast angle was more effective than a 45 0 blast angle. In these tests there was no discernible effect of blast distance between 1 and 3 ft

rf traveling-wave electron gun for photoinjectors

Directory of Open Access Journals (Sweden)

Mattia Schaer

2016-07-01

Full Text Available The design of a photoinjector, in particular that of the electron source, is of central importance for free electron laser (FEL machines where a high beam brightness is required. In comparison to standard designs, an rf traveling-wave photocathode gun can provide a more rigid beam with a higher brightness and a shorter pulse. This is illustrated by applying a specific optimization procedure to the SwissFEL photoinjector, for which a brightness improvement up to a factor 3 could be achieved together with a double gun output energy compared to the reference setup foreseeing a state-of-the-art S-band rf standing-wave gun. The higher brightness is mainly given by a (at least double peak current at the exit of the gun which brings benefits for both the beam dynamics in the linac and the efficiency of the FEL process. The gun design foresees an innovative coaxial rf coupling at both ends of the structure which allows a solenoid with integrated bucking coil to be placed around the cathode in order to provide the necessary focusing right after emission.

Predicting Postprobationary Job Performance of Police Officers Using CPI and MMPI-2-RF Test Data Obtained During Preemployment Psychological Screening.

Science.gov (United States)

Roberts, Ryan M; Tarescavage, Anthony M; Ben-Porath, Yossef S; Roberts, Michael D

2018-02-09

We examined associations between prehire California Psychological Inventory (CPI) and prorated Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) scores (calculated from MMPI profiles) and supervisor ratings for a sample of 143 male police officers. Substantive scale scores in this sample were meaningfully lower than those obtained by the tests' normative samples in the case of the MMPI-2-RF and meaningfully higher in the case of the CPI (indicating less psychological dysfunction). Test scores from both instruments showed substantial range restriction, consistent with those produced by members of the police candidate comparison groups (Corey & Ben-Porath, 2014 ; Roberts & Johnson, 2001 ). After applying a statistical correction for range restriction, we found a number of meaningful associations between both CPI and MMPI-2-RF substantive scale scores and supervisor ratings. For the MMPI-2-RF, findings for scales from the emotional dysfunction and interpersonal functioning domains of the test were particularly strong. For the CPI, findings for scales indicating conformity with social norms, integrity, and tolerance were strong, as were the findings for an index indicating risk of termination. Hierarchical regression analyses showed that MMPI-2-RF and CPI scores complement each other, accounting for incremental variance in the prediction of job-related variables over and above each other. Implications of these findings for assessment science and practice are discussed.

The minimum sit-to-stand height test: reliability, responsiveness and relationship to leg muscle strength.

Science.gov (United States)

Schurr, Karl; Sherrington, Catherine; Wallbank, Geraldine; Pamphlett, Patricia; Olivetti, Lynette

2012-07-01

To determine the reliability of the minimum sit-to-stand height test, its responsiveness and its relationship to leg muscle strength among rehabilitation unit inpatients and outpatients. Reliability study using two measurers and two test occasions. Secondary analysis of data from two clinical trials. Inpatient and outpatient rehabilitation services in three public hospitals. Eighteen hospital patients and five others participated in the reliability study. Seventy-two rehabilitation unit inpatients and 80 outpatients participated in the clinical trials. The minimum sit-to-stand height test was assessed using a standard procedure. For the reliability study, a second tester repeated the minimum sit-to-stand height test on the same day. In the inpatient clinical trial the measures were repeated two weeks later. In the outpatient trial the measures were repeated five weeks later. Knee extensor muscle strength was assessed in the clinical trials using a hand-held dynamometer. The reliability for the minimum sit-to-stand height test was excellent (intraclass correlation coefficient (ICC) 0.91, 95% confidence interval (CI) 0.81-0.96). The standard error of measurement was 34 mm. Responsiveness was moderate in the inpatient trial (effect size: 0.53) but small in the outpatient trial (effect size: 0.16). A small proportion (8-17%) of variability in minimum sit-to-stand height test was explained by knee extensor muscle strength. The minimum sit-to-stand height test has excellent reliability and moderate responsiveness in an inpatient rehabilitation setting. Responsiveness in an outpatient rehabilitation setting requires further investigation. Performance is influenced by factors other than knee extensor muscle strength.

Design and construction of a 500 KW CW, 400 MHz klystron to be used as RF power source for LHC/RF component tests

CERN Document Server

Frischholz, Hans; Pearson, C

1998-01-01

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 t...

PROPOSAL FOR BUILD A TEST STAND TO THE STUDY WATER RAM BASED ON THE RECOMMENDATIONS CONSTRUCTION

Directory of Open Access Journals (Sweden)

Dariusz GRYGO

2016-05-01

Full Text Available The main aim of this article was developed of a test stand to a study physics phenomena accruing at work in a ram water based on the construction recommendations. The experience gained by a number of attempts allowed to the developed construction recommendations that allowed to adjust the test stand to perform various studies of physics phenomena occurring at the work of water ram and easy adaptions to the new requirements. The article includes: the review of the test stands on which performed the study in the history and in the present times, description of the construction recommendations of the universal test stand and the proposal of the test stand developed based on the construction recommendations. Motivation to take up this issue follows from the interest of devices that work in an unconventional way, devices used a renewable energy that can be used in household e.g. to improve their energy balance, delivery water to houses, drinking water for animals, fields irrigation, etc. Analysis of the literature of the water ram, test stands and their performance shown that it is small and typically old development in popular science form. In times of intensive search new sources of renewable energy reactivation of this type equipment may be highly probable.

Measurements of Ion Selective Containment on the RF Charge Breeder Device BRIC

CERN Document Server

Variale, Vincenzo; Batazova, Marina; Boggia, Antonio; Clauser, Tarcisio; Kuznetsov, Gennady I; Rainò, Antonio; Shiyankov, Sergey; Skarbo, Boris A; Valentino, Vincenzo; Verrone, Grazia

2005-01-01

The "charge state breeder" BRIC (BReeding Ion Charge) is based on an EBIS source and it is designed to accept Radioactive Ion Beam (RIB) with charge +1, in a slow injection mode, to increase their charge state up to +n. BRIC has been developed at the INFN section of Bari (Italy) during these last 3 years with very limited funds. Now, it has been assembled at the LNL (Italy) where are in progress the first tests as stand alone source. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion drift chamber, of a Radio Frequency (RF) Quadrupole aiming to filtering the unwanted elements and then making a more efficient containment of the wanted ions. In this contribution, the measurements of the selective effect on the ion charge state containement of the RF quadrupole field, applied on the ion chamber, will be reported and discussed. The ion charge state analisys of the ions trapped in BRIC seem confirm, as foreseen by simulation results carried out previously, that the s...

Microfluidic stretchable RF electronics.

Science.gov (United States)

Cheng, Shi; Wu, Zhigang

2010-12-07

Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum

Science.gov (United States)

Brady, David; White, Harold G.; March, Paul; Lawrence, James T.; Davies, Frank J.

2014-01-01

This paper describes the eight-day August 2013 test campaign designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma. This paper will not address the physics of the quantum vacuum plasma thruster, but instead will describe the test integration, test operations, and the results obtained from the test campaign. Approximately 30-50 micro-Newtons of thrust were recorded from an electric propulsion test article consisting primarily of a radio frequency (RF) resonant cavity excited at approximately 935 megahertz. Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level, within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure. Several different test configurations were used, including two different test articles as well as a reversal of the test article orientation. In addition, the test article was replaced by an RF load to verify that the force was not being generated by effects not associated with the test article. The two test articles were designed by Cannae LLC of Doylestown, Pennsylvania. The torsion pendulum was designed, built, and operated by Eagleworks Laboratories at the NASA Johnson Space Center of Houston, Texas. Approximately six days of test integration were required, followed by two days of test operations, during which, technical issues were discovered and resolved. Integration of the two test articles and their supporting equipment was performed in an iterative fashion between the test bench and the vacuum chamber. In other words, the test article was tested on the bench, then moved to the chamber, then moved back as needed to resolve issues. Manual frequency control was required throughout the test. Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not

Amorphous NEA Silicon Photocathodes - A Robust RF Gun Electron Source. Final Report

International Nuclear Information System (INIS)

Mulhollan, Gregory A.

2009-01-01

Amorphous silicon (a-Si) has been shown to have great promise as a negative electron affinity visible wavelength photocathode suitable for radio frequency (RF) gun systems. The specific operating wavelength can be shifted by growing it as a germanium alloy (a-Si(1-x)Ge(x)) rather than as pure silicon. This class of photoemitters has been shown to possess a high degree of immunity to charged particle flux. Such particle flux can be a significant problem in the operation of other photocathodes in RF gun systems. Its emission characteristics in the form of current per unit area, or current density, and emission angle, or beam spread are well matched for use in RF guns. Photocathodes made of a-Si can be fabricated on a variety of substrates including those most commonly employed in RF gun systems. Such photocathodes can be made for operation in either transmission or reflection mode. By growing them utilizing radio frequency plasma enhanced chemical vapor deposition, the unit cost is quite low, the quality is high and it is straightforward to grow custom size substrates and full or limited regions to confine the electron emission to the desired area. Quality emitters have been fabricated on tantalum, molybdenum, tungsten, titanium, copper, stainless steel, float glass, borosilicate glass and gallium arsenide. In addition to performing well in dedicated test chambers, a-Si photocathodes have been shown to function well in self-contained vacuum tubes. In this employment, they are subjected to a strenuous environment. Successful operation in this configuration provides additional confidence in their application to high energy linac photoinjectors and potentially as part of reliable, low cost photocathode driven RF gun systems that could become ready replacements for the diode and triode guns used on medical accelerators. Their applications in stand-alone vacuum tubes is just beginning to be explored.

RF Pulsed Heating

Energy Technology Data Exchange (ETDEWEB)

Pritzkau, David P.

2002-01-03

RF pulsed heating is a process by which a metal is heated from magnetic fields on its surface due to high-power pulsed RF. When the thermal stresses induced are larger than the elastic limit, microcracks and surface roughening will occur due to cyclic fatigue. Pulsed heating limits the maximum magnetic field on the surface and through it the maximum achievable accelerating gradient in a normal conducting accelerator structure. An experiment using circularly cylindrical cavities operating in the TE{sub 011} mode at a resonant frequency of 11.424 GHz is designed to study pulsed heating on OFE copper, a material commonly used in normal conducting accelerator structures. The high-power pulsed RF is supplied by an X-band klystron capable of outputting 50 MW, 1.5 {micro}s pulses. The test pieces of the cavity are designed to be removable to allow testing of different materials with different surface preparations. A diagnostic tool is developed to measure the temperature rise in the cavity utilizing the dynamic Q change of the resonant mode due to heating. The diagnostic consists of simultaneously exciting a TE{sub 012} mode to steady-state in the cavity at 18 GHz and measuring the change in reflected power as the cavity is heated from high-power pulsed RF. Two experimental runs were completed. One run was executed at a calculated temperature rise of 120 K for 56 x 10{sup 6} pulses. The second run was executed at a calculated temperature rise of 82 K for 86 x 10{sup 6} pulses. Scanning electron microscope pictures show extensive damage occurring in the region of maximum temperature rise on the surface of the test pieces.

Development of L-band pillbox RF window

International Nuclear Information System (INIS)

Takeuchi, Y.; Fukuda, S.; Hisamatsu, H.; Saito, Y.; Takahashi, A.

1994-01-01

A pillbox RF output window was developed for the L-band pulsed klystron for the Japanese Hadron Project (JHP) 1-GeV proton linac. The window was designed to withstand a peak RF power of 6 MW, where the pulse width is 600 μsec and the repetition rate is 50 Hz. A high power model was fabricated using an alumina ceramic which has a low loss tangent of 2.5x10 -5 . A high power test was successfully performed up to a 113 kW RF average power with a 4 MW peak power, a 565 μsec pulse width and a 50 Hz repetition rate. By extrapolating the data of this high power test, the temperature rise of the ceramic is estimated low enough at the full RF power of 6 MW. Thus this RF window is expected to satisfy the specifications of the L-band Klystron. (author)

Operational Performance and Improvements to the RF Power Sources for the Compact Linear Collider Test Facility (CTF3) at CERN

CERN Document Server

McMonagle, Gerard

2006-01-01

The CERN CTF3 facility is being used to test and demonstrate key technical issues for the CLIC (Compact Linear Collider) study. Pulsed RF power sources are essential elements in this test facility. Klystrons at S-band (29998.55 GHz), in conjunction with pulse compression systems, are used to power the Drive Beam Accelerator (DBA) to achieve an electron beam energy of 150 MeV. The L-Band RF system, includes broadband Travelling Wave Tubes (TWTs) for beam bunching with 'phase coded' sub pulses in the injector and a narrow band high power L-Band klystron powering the transverse 1.5GHz RF deflector in the Delay Loop immediately after the DBA. This paper describes these different systems and discusses their operational performance.

Operational performance and improvements to the rf power sources for the Compact Linear Collider Test Facility (CTF3) at CERN

CERN Document Server

McMonagle, Gerard

2006-01-01

The CERN CTF3 facility is being used to test and demonstrate key technical issues for the CLIC (Compact Linear Collider) study. Pulsed RF power sources are essential elements in this test facility. Klystrons at S-band (29998.55 GHz), in conjunction with pulse compression systems, are used to power the Drive Beam Accelerator (DBA) to achieve an electron beam energy of 150 MeV. The L-Band RF system, includes broadband Travelling Wave Tubes (TWTs) for beam bunching with 'phase coded' sub pulses in the injector and a narrow band high power L-Band klystron powering the transverse 1.5 GHz RF deflector in the Delay Loop immediately after the DBA. This paper describes these different systems and discusses their operational performance.

Practical guide to RF-MEMS

CERN Document Server

Iannacci, Jacopo

2013-01-01

Closes the gap between hardcore-theoretical and purely experimental RF-MEMS books. The book covers, from a practical viewpoint, the most critical steps that have to be taken in order to develop novel RF-MEMS device concepts. Prototypical RF-MEMS devices, both including lumped components and complex networks, are presented at the beginning of the book as reference examples, and these are then discussed from different perspectives with regard to design, simulation, packaging, testing, and post-fabrication modeling. Theoretical concepts are introduced when necessary to complement the practical

1+-n+ ECR ION SOURCE DEVELOPMENT TEST STAND

International Nuclear Information System (INIS)

Donald P. May

2006-01-01

A test stand for the investigation of 1+-n+ charge boosting using an ECR ion sources is currently being assembled at the Texas A and M Cyclotron Institute. The ultimate goal is to relate the charge-boosting of ions of stable species to possible charge-boosting of ions of radioactive species extracted from the diverse, low-charge-state ion sources developed for radioactive ion beams

Commissioning and First Results from the Fermilab Cryomodule Test Stand

Energy Technology Data Exchange (ETDEWEB)

Harms, Elvin; et al.

2017-05-01

A new test stand dedicated to SRF cryomodule testing, CMTS1, has been commissioned and is now in operation at Fermilab. The first device to be cooled down and powered in this facility is the prototype 1.3 GHz cryomodule assembled at Fermilab for LCLS-II. We describe the demonstrated capabilities of CMTS1, report on steps taken during commissioning, provide an overview of first test results, and survey future plans.

Development of C-band High-Power Mix-Mode RF Window

CERN Document Server

Michizono, S; Matsumoto, T; Nakao, K; Takenaka, T

2004-01-01

High power c-band (5712 MHz) rf system (40 MW, 2 μs, 50 Hz) is under consideration for the electron-linac upgrade aimed for the super KEKB project. An rf window, which isolates the vacuum and pass the rf power, is one of the most important components for the rf system. The window consists of a ceramic disk and a pill-box housing. The mix-mode rf window is designed so as to decrease the electric field on the periphery of the ceramic disk. A resonant ring is assembled in order to examine the high-power transmission test. The window was tested up to the transmission power of 160 MW. The rf losses are also measured during the rf operation.

Tandem Mirror Experiment-Upgrade neutral beam test stand: A powerful tool for development and quality assurance

International Nuclear Information System (INIS)

Hibbs, S.M.; Kane, R.J.; Kerr, R.G.; Poulsen, P.

1983-01-01

During construction of the Tandem Mirror Experiment-Upgrade (TMX-U), a test stand was assembled to develop electronics for the neutral beam system. In the first six months of test stand use the authors operated a few neutral beam injector modules and directed considerable effort toward improving the electronic system. As system development progressed, the focus turned toward improving the injector modules themselves. The test stand has proved to be the largest single contributor to the successful operation of neutral beams on TMX-U, primarily because it provides quality assurance and development capability in conjunction with the scheduled activities of the main experiment. This support falls into five major categories: (1) electronics development, (2) operator training, (3) injector module testing and characterization, (4) injector module improvements, and (5) physics improvements (through areas affected by injector operation). Normal day-to-day operation of the test stand comes under the third category, testing and characterization, and comprises the final quality assurance activity for newly assembled or repaired modules before they are installed on TMX-U. They have also used the test stand to perform a series of physics experiments, including: reducing gas flow through valve and arc chamber characterization, reducing impurities by titanium gettering, and reducing streaming gas using apertures and collisional gas dynamics

Design and simulations for RFPI system test jig

International Nuclear Information System (INIS)

Keshwani, Rajesh; Khole, Shailesh; Sujo, C.I.; Shukla, Hitesh; Afaash, M.; Bharade, Sandeep; Joshi, Gopal

2015-01-01

RFPI system for condition monitoring and protection of RF systems of LEHIPA has been designed. The intention of this system is to protect and monitor different high power RF components. The system consists of variety of analog and digital cards to process, acquire and monitor signals from RF sensors, photo multiplier tubes (PMT), field emission probes, photo sensors, etc. The system can also accept and process digital inputs or contacts and analog input signals from other subsystems, indicating their status. It comprises of analog signal processing electronics, condition monitoring, data acquisition and fault reporting features. Since RFPI system should process and take action within prescribed time limit, the testing of system is critical issue. In order to carry out stand-alone field testing of such elaborate electronic system, variety of carefully designed electronic test circuit with suitable rangeability is required. These include fast current sources, fast amplifiers, fast rectifiers, etc. This paper elaborates on specifications, design approach, circuit design and simulations for various circuits used in test jig

Ethernet-based test stand for a CAN network

Science.gov (United States)

Ziebinski, Adam; Cupek, Rafal; Drewniak, Marek

2017-11-01

This paper presents a test stand for the CAN-based systems that are used in automotive systems. The authors propose applying an Ethernet-based test system that supports the virtualisation of a CAN network. The proposed solution has many advantages compared to classical test beds that are based on dedicated CAN-PC interfaces: it allows the physical constraints associated with the number of interfaces that can be simultaneously connected to a tested system to be avoided, which enables the test time for parallel tests to be shortened; the high speed of Ethernet transmission allows for more frequent sampling of the messages that are transmitted by a CAN network (as the authors show in the experiment results section) and the cost of the proposed solution is much lower than the traditional lab-based dedicated CAN interfaces for PCs.

Method’s and Test Stand for Electronic PID Controller

Directory of Open Access Journals (Sweden)

Cristian Paul Chioncel

2009-01-01

Full Text Available The paper presents method’s and a testing stand for electronic controller using for this a signal generator and a digital oscilloscope respectively the virtual instrumentation and the signal acquisitions from the controllers input and output through an data acquisition board and an PC on that Lab View program runs.

Fiber Optic Telemetry System for LLL High-Voltage Test Stand

International Nuclear Information System (INIS)

Richter, J.P.

1977-01-01

This paper describes the Fiber Optic Telemetry System designed to operate in the hostile particle and electromagnetic radiation environment of the High Voltage Test Stand. It discusses system criteria, components, packaging, and performance. In all tests to date, the system exceeds its design goals with very comfortable margins. It is well advanced into the fabrication stages with all crucial components tested and only straightforward TTL (Transistor Transistor Logic) circuitry to be completed

ATLAS RPC performance on a dedicated cosmic ray test-stand

International Nuclear Information System (INIS)

Liberti, B.; Aielli, G.; Camarri, P.; Cardarelli, R.; Corradi, M.; Di Ciaccio, A.; Di Stante, L.; Palummo, L.; Pastori, E.; Salamon, A.; Santonico, R.; Solfaroli, E.

2008-01-01

596 RPC chambers have been assembled in the ATLAS Muon Spectrometer, covering a 7300 m 2 sensitive area with 355.000 read out channels. 1116 RPC Units were produced and tested before integration and installation on the experiment [A. Aloisio et al., 'The trigger chambers of the ATLAS muon spectrometer: production and tests', Nuclear Instruments and Methods A535 (2004) 265-271]. 192 ATLAS RPCs, the Barrel Outer Large (BOL) units were tested in INFN Roma Tor Vergata test stand

Investigation of High Voltage Breakdown and Arc Localization in RF Structures

International Nuclear Information System (INIS)

Bigelow, T.S.; Goulding, R.H.; Swain, D.W.

1999-01-01

An effort is underway to improve the voltage standoff capabilities of ion cyclotron range of frequencies (ICRF) heating and current drive systems. One approach is to develop techniques for determining the location of an electrical breakdown (arc) when it occurs. A technique is described which uses a measurement of the reflection coefficient of a swept frequency signal to determine the arc location. The technique has several advantages including a requirement for only a small number of sensors and very simple data interpretation. In addition a test stand is described which will be used for studies of rf arc behavior. The device uses a quarter-wave resonator to produce voltages to 90 kV in the frequency range of 55-80 MHz

Pulsed rf superconductivity program at SLAC

International Nuclear Information System (INIS)

Campisi, I.E.; Farkas, Z.D.

1984-08-01

Recent tests performed at SLAC on superconducting TM 010 caavities using short rf pulses (less than or equal to 2.5 μs) have established that at the cavity surface magnetic fields can be reached in the vicinity of the theoretical critical fields without an appreciable increase in average losses. Tests on niobium and lead cavities are reported. The pulse method seems to be best suited to study peak field properties of superconductors in the microwave band, without the limitations imposed by defects. The short pulses also seem to be more effective in decreasing the causes of field emission by rf processing. Applications of the pulsed rf superconductivity to high-gradient linear accelerators are also possible

Test results of the AGS Booster low frequency RF system

International Nuclear Information System (INIS)

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

1993-01-01

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

Design and manufacture of the RF power supply and RF transmission line for SANAEM project Prometheus

Science.gov (United States)

Turemen, G.; Ogur, S.; Ahiska, F.; Yasatekin, B.; Cicek, E.; Ozbey, A.; Kilic, I.; Unel, G.; Alacakir, A.

2017-08-01

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 primary goal 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. Additionally low and high power RF test results are presented to compare the performances of the locally produced components to the commercially available ones.

Impact of one's own mobile phone in stand-by mode on personal radiofrequency electromagnetic field exposure.

Science.gov (United States)

Urbinello, Damiano; Röösli, Martin

2013-01-01

When moving around, mobile phones in stand-by mode periodically send data about their positions. The aim of this paper is to evaluate how personal radiofrequency electromagnetic field (RF-EMF) measurements are affected by such location updates. Exposure from a mobile phone handset (uplink) was measured during commuting by using a randomized cross-over study with three different scenarios: disabled mobile phone (reference), an activated dual-band phone and a quad-band phone. In the reference scenario, uplink exposure was highest during train rides (1.19 mW/m(2)) and lowest during car rides in rural areas (0.001 mW/m(2)). In public transports, the impact of one's own mobile phone on personal RF-EMF measurements was not observable because of high background uplink radiation from other people's mobile phone. In a car, uplink exposure with an activated phone was orders of magnitude higher compared with the reference scenario. This study demonstrates that personal RF-EMF exposure is affected by one's own mobile phone in stand-by mode because of its regular location update. Further dosimetric studies should quantify the contribution of location updates to the total RF-EMF exposure in order to clarify whether the duration of mobile phone use, the most common exposure surrogate in the epidemiological RF-EMF research, is actually an adequate exposure proxy.

CAT/RF Simulation Lessons Learned

Science.gov (United States)

2003-06-11

IVSS-2003-MAS-7 CAT /RF Simulation Lessons Learned Christopher Mocnik Vetronics Technology Area, RDECOM TARDEC Tim Lee DCS Corporation...developed a re- configurable Unmanned Ground Vehicle (UGV) simulation for the Crew integration and Automation Test bed ( CAT ) and Robotics Follower (RF...Advanced Technology Demonstration (ATD) experiments. This simulation was developed as a component of the Embedded Simulation System (ESS) of the CAT

Upgrade of the cryogenic infrastructure of SM18, CERN main test facility for superconducting magnets and RF cavities

Science.gov (United States)

Perin, A.; Dhalla, F.; Gayet, P.; Serio, L.

2017-12-01

SM18 is CERN main facility for testing superconducting accelerator magnets and superconducting RF cavities. Its cryogenic infrastructure will have to be significantly upgraded in the coming years, starting in 2019, to meet the testing requirements for the LHC High Luminosity project and for the R&D program for superconducting magnets and RF equipment until 2023 and beyond. This article presents the assessment of the cryogenic needs based on the foreseen test program and on past testing experience. The current configuration of the cryogenic infrastructure is presented and several possible upgrade scenarios are discussed. The chosen upgrade configuration is then described and the characteristics of the main newly required cryogenic equipment, in particular a new 35 g/s helium liquefier, are presented. The upgrade implementation strategy and plan to meet the required schedule are then described.

Make-up of injector test stand (ITS-1) and preliminary results with Model-I ion source

International Nuclear Information System (INIS)

Matsuda, S.; Ito, T.; Kondo, U.; Ohara, Y.; Oga, T.; Shibata, T.; Shirakata, H.; Sugawara, T.; Tanaka, S.

Constitution of the 1-st injector test stand (ITS-1) in the Thermonuclear Division, JAERI, and the performance of the Model-I ion source are described. Heating a plasma by neutral beam injection is one of the promising means in the thermonuclear fusion devices. Purpose of the test stand is to develop the ion sources used in such injection systems. The test stand was completed in February 1975, which is capable of testing the ion sources up to 12 amps at 30 kV. A hydrogen ion beam of 5.5 amps at 25 kV was obtained in the Model-I ion source

Operational Performance and Improvements to the RF Power Sources for the Compact Linear Collider Test Facility (CTF3) at CERN

OpenAIRE

McMonagle, Gerard

2006-01-01

The CERN CTF3 facility is being used to test and demonstrate key technical issues for the CLIC (Compact Linear Collider) study. Pulsed RF power sources are essential elements in this test facility. Klystrons at S-band (29998.55 GHz), in conjunction with pulse compression systems, are used to power the Drive Beam Accelerator (DBA) to achieve an electron beam energy of 150 MeV. The L-Band RF system, includes broadband Travelling Wave Tubes (TWTs) for beam bunching with 'phase coded' sub pulses ...

High RF power test of a lower hybrid module mock-up in Carbon Fiber Composite

International Nuclear Information System (INIS)

Maebara, Sunao; Kiyono, Kimihiro; Seki, Masami

1997-11-01

A mock-up module of a Lower Hybrid Current Drive antenna module of a Carbon Fiber Composite (CFC) was fabricated for the development of heat resistive front facing the plasma. This module is made from CFC plates and rods which are copper coated to reduce the RF losses. The withstand-voltage, the RF properties and outgassing rates for long pulses and high RF power were tested at the Lower Hybrid test bed facility of Cadarache. After the short pulse conditioning, long pulses with a power density ranging between 50 and 150 MW/m 2 were performed with no breakdowns. During these tests, the module temperature was increasing from 100-200degC to 400-500degC. It was also checked that high power density, up to 150 MW/m 2 , could be transmitted when the waveguides are filled with H 2 at a pressure of 5 x 10 -2 Pa. No significant change in the reflection coefficient is measured after the long pulse operation. During a long pulse, the power reflection increases during the pulse typically from 0.8 % to 1.3 %. It is concluded that the outgassing rate of Cu-plated CFC is about 6-7 times larger than of Dispersion Strengthened Copper (DSC) module at the module temperature of 300degC. No significant increase of the global outgassing of the CFC module was measured after hydrogen prefilling. After the test, visual inspection revealed that peeling of the copper coating occurred at one end of the module only on a very small area (0.2 cm 2 ). It is assessed that a CFC module is an attractive candidate for the hardening of the tip of the LHCD antenna. (author)

High RF power test of a lower hybrid module mock-up in carbon fiber composite

International Nuclear Information System (INIS)

Goniche, M.; Bibet, P.; Brossaud, J.; Cano, V.; Froissard, P.; Kazarian, F.; Rey, G.; Maebara, S.; Kiyono, K.; Seki, M.; Suganuma, K.; Ikeda, Y.; Imai, T.

1999-02-01

A mock-up module of a Lower Hybrid Current Drive antenna module of a Carbon Fiber Composite (CFC) was fabricated for the development of heat resistive front facing the plasma. This module is made from CFC plates and rods which are copper coated to reduce the RF losses. The withstand-voltage, the RF properties and outgassing rates for long pulses and high RF power were tested at the Lower Hybrid test bed facility of Cadarache. After the short pulse conditioning, long pulses with a power density ranging between 50 and 150 MW/m 2 were performed with no breakdowns. During these tests, the module temperature was increasing from 100-200 deg. C to 400-500 deg. C. It was also checked that high power density, up to 150 MW/m 2 , could be transmitted when the waveguides are filled with H 2 at a pressure of 5 x 10 -2 Pa. No significant change in the reflection coefficient is measured after the long pulse operation. During a long pulse, the power reflection increases during the pulse typically from 0.8% to 1.3%. It is concluded that the outgassing rate of Cu-plated CFC is about 6 times larger than of Dispersion Strengthened Copper (DSC) module at the module temperature of 300 deg. C. No significant increase of the global outgassing of the CFC module was measured after hydrogen pre-filling. After the test, visual inspection revealed that peeling of the copper coating occurred at one end of the module only on a very small area (0.2 cm 2 ). It is assessed that a CFC module is an attractive candidate for the hardening of the tip of the LHCD antenna. (authors)

Development, test and flight results of the rf systems for the yes2 tether experiment

NARCIS (Netherlands)

Cucarella, Guillermina Castillejo; Cichocki, Andrzej; Burla, M.

2008-01-01

This paper highlights design, realization, testing and flight results of the Radio Frequency developments (RF) for ESA's second Young Engineers' Satellite (YES2), that included GPS systems, an intersatellite UHF link and a re-entry capsule telemetry and recovery system. The YES2 piggybacked on the

Tandem mirror experiment-upgrade neutral beam test stand: a powerful tool for development and quality assurance

International Nuclear Information System (INIS)

Hibbs, S.M.; Kane, R.J.; Kerr, R.G.; Poulsen, P.

1983-01-01

During construction of the Tandem Mirror Experiment-Upgrade (TMX-U), we assembled a test stand to develop electronics for the neutral beam system. In the first six months of test stand use we operated a few neutral beam injector modules and directed considerable effort toward improving the electronic system. As system development progressed, our focus turned toward improving the injector modules themselves. The test stand has proved to be the largest single contributor to the successful operation of neutral beams on TMX-U, primarily because it provides quality assurance andd development capability in conjunction with the scheduled activities of the main experiment. This support falls into five major categories: (1) electronics development, (2) operator training, (3) injector module testing and characterization, (4) injector module improvements, and (5) physics improvements (through areas affected by injector operation). Normal day-to-day operation of the test stand comes under the third category, testing and characterization, and comprises our final quality assurance activity for newly assembled or repaired modules before they are installed on TMX-U

Development of a bellows assembly with RF-shield for KEKB II: abrasion and pumping down tests

International Nuclear Information System (INIS)

Suetsugu, Yusuke; Kanazawa, Ken-ichi; Kawahara, Masaharu; Harada, Yosuke; Kaneko, Motosada

1997-01-01

A bellows assembly with RF-shield as been designed and developed for the KEK B-factory (KEKB). The RF-shield is a usual finger-type but has special spring-fingers to press contact-fingers (shield-fingers) surely onto inner tube (beam tube). In a chain of design studies an abrasion test of the contact-fingers was performed in vacuum. A quantity of generated metal particles was estimated and expected to have little harm on the beam lifetime if the inner tube is coated with silver. The gas desorption rate and the residual gas components of the bellows assembly were also measured as a final bench test. The gas desorption rate of 1 - 1.5x10 -10 Pa·l/s/cm 2 was obtained after a bake at 150degC for 24 hours. (author)

Astronaut Ronald Sega with Wake Shield Facility on test stand at JSC

Science.gov (United States)

1991-01-01

The Wake Shield Facility is displayed on a test stand at JSC. Astronaut Ronald M. Sega, mission specialist for STS-60, is seen with the facility during a break in testing in the acoustic and vibration facility at JSC.

Integrated System Health Management: Pilot Operational Implementation in a Rocket Engine Test Stand

Science.gov (United States)

Figueroa, Fernando; Schmalzel, John L.; Morris, Jonathan A.; Turowski, Mark P.; Franzl, Richard

2010-01-01

This paper describes a credible implementation of integrated system health management (ISHM) capability, as a pilot operational system. Important core elements that make possible fielding and evolution of ISHM capability have been validated in a rocket engine test stand, encompassing all phases of operation: stand-by, pre-test, test, and post-test. The core elements include an architecture (hardware/software) for ISHM, gateways for streaming real-time data from the data acquisition system into the ISHM system, automated configuration management employing transducer electronic data sheets (TEDS?s) adhering to the IEEE 1451.4 Standard for Smart Sensors and Actuators, broadcasting and capture of sensor measurements and health information adhering to the IEEE 1451.1 Standard for Smart Sensors and Actuators, user interfaces for management of redlines/bluelines, and establishment of a health assessment database system (HADS) and browser for extensive post-test analysis. The ISHM system was installed in the Test Control Room, where test operators were exposed to the capability. All functionalities of the pilot implementation were validated during testing and in post-test data streaming through the ISHM system. The implementation enabled significant improvements in awareness about the status of the test stand, and events and their causes/consequences. The architecture and software elements embody a systems engineering, knowledge-based approach; in conjunction with object-oriented environments. These qualities are permitting systematic augmentation of the capability and scaling to encompass other subsystems.

Design of a quadrotor flight test stand for system identification

CSIR Research Space (South Africa)

Beharie, MM

2015-01-01

Full Text Available This paper presents the design, development and construction of a flight test stand for a quadrotor UAV. As opposed to alternate forms of UAV, the power plant in the case of the quadrotor serves a dual purpose of control and propulsion. Since...

Voltage uniformity study in large-area reactors for RF plasma deposition

Energy Technology Data Exchange (ETDEWEB)

Sansonnens, L.; Pletzer, A.; Magni, D.; Howling, A.A.; Hollenstein, C. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP); Schmitt, J.P.M. [Balzers Process Systems, Palaiseau (France)

1996-09-01

Non-uniform voltage distribution across the electrode area results in inhomogeneous thin-film RF plasma deposition in large area reactors. In this work, a two-dimensional analytic model for the calculation of the voltage distribution across the electrode area is presented. The results of this model are in good agreement with measurements performed without plasma at 13.56 MHz and 70 MHz in a large area reactor. The principal voltage inhomogeneities are caused by logarithmic singularities in the vicinity of RF connections and not by standing waves. These singularities are only described by a two-dimensional model and cannot be intuitively predicted by analogy to a one-dimensional case. Plasma light emission measurements and thickness homogeneity studies of a-Si:H films show that the plasma reproduces these voltage inhomogeneities. Improvement of the voltage uniformity is investigated by changing the number and position of the RF connections. (author) 13 figs., 20 refs.

High-power tests of a single-cell copper accelerating cavity driven by two input couplers

International Nuclear Information System (INIS)

Horan, D.; Bromberek, D.; Meyer, D.; Waldschmidt, G.

2008-01-01

High-power tests were conducted on a 350-MHz, single-cell copper accelerating cavity driven simultaneously by two H-loop input couplers for the purpose of determining the reliability, performance, and power-handling capability of the cavity and related components, which have routinely operated at 100-kW power levels. The test was carried out utilizing the APS 350-MHz RF Test Stand, which was modified to split the input rf power into two frac12-power feeds, each supplying power to a separate H-loop coupler on the cavity. Electromagnetic simulations of the two-coupler feed system were used to determine coupler match, peak cavity fields, and the effect of phasing errors between the coupler feed lines. The test was conducted up to a maximum total rf input power of 164-kW CW. Test apparatus details and performance data will be presented.

RF windows used at s-band pulsed klystrons in KEK linac

Energy Technology Data Exchange (ETDEWEB)

Michizono, S.; Saito, Y. [KEK, National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1997-04-01

The breakdown of the alumina RF-windows used in high-power klystrons is one of the most serious problems in the development of klystrons. This breakdown results from excess heating of alumina due to multipactor bombardments and/or localized RF dissipations. A statistical research of window materials was carried out, and high-power tests were performed in order to develop RF windows having high durability for the KEKB klystrons. The breakdown mechanism of RF windows is being considered. An improved RF window installed in a KEKB klystron is also being tested. (J.P.N)

Z-2 Suit Support Stand and MKIII Suit Center of Gravity Test

Science.gov (United States)

Nguyen, Tuan Q.

2014-01-01

NASA's next generation spacesuits are the Z-Series suits, made for a range of possible exploration missions in the near future. The prototype Z-1 suit has been developed and assembled to incorporate new technologies that has never been utilized before in the Apollo suits and the Extravehicular Mobility Unit (EMU). NASA engineers tested the Z-1 suit extensively in order to developed design requirements for the new Z-2 suit. At the end of 2014, NASA will be receiving the new Z-2 suit to perform more testing and to further develop the new technologies of the suit. In order to do so, a suit support stand will be designed and fabricated to support the Z-2 suit during maintenance, sizing, and structural leakage testing. The Z-2 Suit Support Stand (Z2SSS) will be utilized for these purposes in the early testing stages of the Z-2 suit.

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

International Nuclear Information System (INIS)

Chen, Zukun

2011-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Chen, Zukun [Los Alamos National Laboratory

2011-01-01

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

Short-Period RF Undulator for a SASE Nanometer source

International Nuclear Information System (INIS)

Hirshfield, Jay L.

2011-01-01

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.

Prototype rf cavity for the HISTRAP accelerator

International Nuclear Information System (INIS)

Mosko, S.W.; Dowling, D.T.; Olsen, D.K.

1989-01-01

HISTRAP, a proposed synchrotron-cooling-storage ring designed to both accelerate and decelerate very highly charged very heavy ions for atomic physics research, requires an rf accelerating system to provide /+-/2.5 kV of peak accelerating voltage per turn while tuning through a 13.5:1 frequency range in a fraction of a second. A prototype half-wave, single gap rf cavity with biased ferrite tuning was built and tested over a continuous tuning range of 200 kHz through 2.7 MHz. Initial test results establish the feasibility of using ferrite tuning at the required rf power levels. The resonant system is located entirely outside of the accelerator's 15cm ID beam line vacuum enclosure except for a single rf window which serves as an accelerating gap. Physical separation of the cavity and the beam line permits in situ vacuum baking of the beam line at 300/degree/C

RF control system of the HIMAC synchrotron

International Nuclear Information System (INIS)

Kanazawa, M.; Sato, K.; Itano, A.

1992-01-01

An RF control system of the HIMAC synchrotron has been constructed. In this control system we have adopted a digital feed back system with a digital synthesizer (DS). Combining a high power system, performance of the control system have been tested in a factory (Toshiba) with a simulator circuit of the synchrotron oscillation. Following this test, We had beam acceleration test with this control system at TARN-II in INS (Institute for Nuclear Study, University of Tokyo). This paper describes the RF control system and its tested results. (author)

A self-adaptive feedforward rf control system for linacs

International Nuclear Information System (INIS)

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

1993-01-01

The design and performance of a self-adaptive feedforward rf control system are reported. The system was built for the linac of the Accelerator Test Facility (ATF) at Brookhaven National Laboratory. Variables of time along the linac macropulse, such as field or phase are discretized and represented as vectors. Upon turn-on or after a large change in the operating-point, the control system acquires the response of the system to test signal vectors and generates a linearized system response matrix. During operation an error vector is generated by comparing the linac variable vectors and a target vector. The error vector is multiplied by the inverse of the system's matrix to generate a correction vector is added to an operating point vector. This control system can be used to control a klystron to produce flat rf amplitude and phase pulses, to control a rf cavity to reduce the rf field fluctuation, and to compensate the energy spread among bunches in a rf linac. Beam loading effects can be corrected and a programmed ramp can be produced. The performance of the control system has been evaluated on the control of a klystron's output as well as an rf cavity. Both amplitude and phase have been regulated simultaneously. In initial tests, the rf output from a klystron has been regulated to an amplitude fluctuation of less than ±0.3% and phase variation of less than ±0.6deg. The rf field of the ATF's photo-cathode microwave gun cavity has been regulated to ±5% in amplitude and simultaneously to ±1deg in phase. Regulating just the rf field amplitude in the rf gun cavity, we have achieved amplitude fluctuation of less than ±2%. (orig.)

Cryogenic System for the Cryomodule Test Stand at Fermilab

Energy Technology Data Exchange (ETDEWEB)

White, Michael J. [Fermilab; Hansen, Benjamin [Fermilab; Klebaner, Arkadiy [Fermilab

2017-10-09

This paper describes the cryogenic system for the Cryomodule Test Stand (CMTS) at the new Cryomodule Test Facility (CMTF) located at Fermilab. CMTS is designed for production testing of the 1.3 GHz and 3.9GHz cryomodules to be used in the Linac Coherent Light Source II (LCLSII), which is an upgrade to an existing accelerator at Stanford Linear Accelerator Laboratory (SLAC). This paper will focus on the cryogenic system that extends from the helium refrigeration plant to the CMTS cave. Topics covered will include component design, installation and commissioning progress, and operational plans. The paper will conclude with a description of the heat load measurement plan.

Liquid Methane Conditioning Capabilities Developed at the NASA Glenn Research Center's Small Multi- Purpose Research Facility (SMiRF) for Accelerated Lunar Surface Storage Thermal Testing

Science.gov (United States)

Bamberger, Helmut H.; Robinson, R. Craig; Jurns, John M.; Grasl, Steven J.

2011-01-01

Glenn Research Center s Creek Road Cryogenic Complex, Small Multi-Purpose Research Facility (SMiRF) recently completed validation / checkout testing of a new liquid methane delivery system and liquid methane (LCH4) conditioning system. Facility checkout validation was conducted in preparation for a series of passive thermal control technology tests planned at SMiRF in FY10 using a flight-like propellant tank at simulated thermal environments from 140 to 350K. These tests will validate models and provide high quality data to support consideration of LCH4/LO2 propellant combination option for a lunar or planetary ascent stage.An infrastructure has been put in place which will support testing of large amounts of liquid methane at SMiRF. Extensive modifications were made to the test facility s existing liquid hydrogen system for compatibility with liquid methane. Also, a new liquid methane fluid conditioning system will enable liquid methane to be quickly densified (sub-cooled below normal boiling point) and to be quickly reheated to saturation conditions between 92 and 140 K. Fluid temperatures can be quickly adjusted to compress the overall test duration. A detailed trade study was conducted to determine an appropriate technique to liquid conditioning with regard to the SMiRF facility s existing infrastructure. In addition, a completely new roadable dewar has been procured for transportation and temporary storage of liquid methane. A new spherical, flight-representative tank has also been fabricated for integration into the vacuum chamber at SMiRF. The addition of this system to SMiRF marks the first time a large-scale liquid methane propellant test capability has been realized at Glenn.This work supports the Cryogenic Fluid Management Project being conducted under the auspices of the Exploration Technology Development Program, providing focused cryogenic fluid management technology efforts to support NASA s future robotic or human exploration missions.

RF properties of high-T/sub c/ superconductors

International Nuclear Information System (INIS)

Bohn, C.L.; Delayen, J.R.; Dos Santos, D.I.; Lanagan, M.T.; Shepard, K.W.

1988-01-01

We have investigated the rf properties of high-T/sub c/ superconductors over a wide range of temperature, frequency, and rf field amplitude. We have tested both bulk polycrystalline samples and thick films on silver substrates. At 150 MHz and 4.2 K, we have measured a surface resistance of 18 μ/sup /OMEGA// at low rf field and 3.6 m/sup /OMEGA// at an rf field of 270 gauss. All samples showed a strong dependence of the surface resistance on rf field; however, no breakdown of the superconducting state has been observed up to the highest field achieved (320 gauss). 9 refs., 4 figs., 1 tab

Saturn V First Stage Leaves the Dynamic Test Stand

Science.gov (United States)

1967-01-01

This photo shows the Saturn V first stage being lowered to the ground following a successful test to determine the effects of continual vibrations simulating the effects of an actual launch. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

HESTIA Commodities Exchange Pallet and Sounding Rocket Test Stand

Science.gov (United States)

Chaparro, Javier

2013-01-01

During my Spring 2016 internship, my two major contributions were the design of the Commodities Exchange Pallet and the design of a test stand for a 100 pounds-thrust sounding rocket. The Commodities Exchange Pallet is a prototype developed for the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) program. Under the HESTIA initiative the Commodities Exchange Pallet was developed as a method for demonstrating multi-system integration thru the transportation of In-Situ Resource Utilization produced oxygen and water to a human habitat. Ultimately, this prototype's performance will allow for future evaluation of integration, which may lead to the development of a flight capable pallet for future deep-space exploration missions. For HESTIA, my main task was to design the Commodities Exchange Pallet system to be used for completing an integration demonstration. Under the guidance of my mentor, I designed, both, the structural frame and fluid delivery system for the commodities pallet. The fluid delivery system includes a liquid-oxygen to gaseous-oxygen system, a water delivery system, and a carbon-dioxide compressors system. The structural frame is designed to meet safety and transportation requirements, as well as the ability to interface with the ER division's Portable Utility Pallet. The commodities pallet structure also includes independent instrumentation oxygen/water panels for operation and system monitoring. My major accomplishments for the commodities exchange pallet were the completion of the fluid delivery systems and the structural frame designs. In addition, parts selection was completed in order to expedite construction of the prototype, scheduled to begin in May of 2016. Once the commodities pallet is assembled and tested it is expected to complete a fully integrated transfer demonstration with the ISRU unit and the Environmental Control and Life Support System test chamber in September of 2016. In addition to the development of

Indirect measurement of motivation: Developing and testing a motivational recoding-free implicit association test (m-IAT-RF)

DEFF Research Database (Denmark)

Kraus, Alexandra Anita; Scholderer, Joachim

2015-01-01

For the indirect measurement of approach-avoidance tendencies, two procedures are introduced and compared. The procedures are modifications of the standard IAT and the Recoding-Free IAT (IAT-RF) and use a motivational attribute dimension (approach, avoidance) instead of an evaluative one. Study 1...... (N = 162) assesses their convergent and discriminant validity with respect to self-reported measures of motivation and evaluation, and their predictive validity with respect to actual behavior. Study 2 (N = 205) furthermore compares their validity to evaluative variants of the same test paradigms...

CERN News: Slow ejection efficiency at the PS; Vacuum tests on the ISR; Fire in the neutrino beam-line; Prototype r.f . cavity for the Booster; Crane-bridge in ISR experimental hall; Modifications to the r.f . system at the PS

CERN Multimedia

1969-01-01

CERN News: Slow ejection efficiency at the PS; Vacuum tests on the ISR; Fire in the neutrino beam-line; Prototype r.f . cavity for the Booster; Crane-bridge in ISR experimental hall; Modifications to the r.f . system at the PS

An algorithm for the design and tuning of RF accelerating structures with variable cell lengths

Science.gov (United States)

Lal, Shankar; Pant, K. K.

2018-05-01

An algorithm is proposed for the design of a π mode standing wave buncher structure with variable cell lengths. It employs a two-parameter, multi-step approach for the design of the structure with desired resonant frequency and field flatness. The algorithm, along with analytical scaling laws for the design of the RF power coupling slot, makes it possible to accurately design the structure employing a freely available electromagnetic code like SUPERFISH. To compensate for machining errors, a tuning method has been devised to achieve desired RF parameters for the structure, which has been qualified by the successful tuning of a 7-cell buncher to π mode frequency of 2856 MHz with field flatness algorithm and tuning method have demonstrated the feasibility of developing an S-band accelerating structure for desired RF parameters with a relatively relaxed machining tolerance of ∼ 25 μm. This paper discusses the algorithm for the design and tuning of an RF accelerating structure with variable cell lengths.

Analog techniques in CEBAF's RF control system

International Nuclear Information System (INIS)

Hovater, C.; Fugitt, J.

1989-01-01

Recent developments in high-speed analog technology have progressed into the areas of traditional RF technology. Diode related devices are being replaced by analog IC's in the CEBAF RF control system. Complex phase modulators and attenuators have been successfully tested at 70 MHz. They have three advantages over existing technology: lower cost, less temperature sensitivity, and more linearity. RF signal conditioning components and how to implement the new analog IC's will be covered in this paper. 4 refs., 5 figs

Analog techniques in CEBAF'S RF control system

International Nuclear Information System (INIS)

Hovater, C.; Fugitt, J.

1989-01-01

Recent developments in high-speed analog technology have progressed into the areas of traditional rf technology. Diode-related devices are being replaced by analog IC's in the CEBAF rf control system. Complex phase modulators and attenuators have been successfully tested at 70 MHz. They have three advantages over existing technology: lower cost, less temperature sensitivity, and more linearity. Rf signal conditioning components and how to implement the new analog IC's will be covered in this paper. 4 refs., 5 figs

Rf Station For Ion Beam Staking In Hirfl-csr

CERN Document Server

Arbuzov, V S; Bushuev, A A; Dranichnikov, A N; Gorniker, E I; Kendjebulatov, E K; Kondakov, A A; Kondaurov, M; Kruchkov, Ya G; Krutikhin, S A; Kurkin, G Ya; Mironenko, L A; Motygin, S V; Osipov, V N; Petrov, V M; Pilan, Andrey M; Popov, A M; Rashenko, V V; Selivanov, A N; Shteinke, A R; Vajenin, N F

2004-01-01

BINP has developed and produced the RF station for Institute of Modern Physics (IMP), Lanzhou, China, for multipurpose accelerator complex with electron cooling. The RF station will be used for accumulation of ion beams in the main ring of the system. It was successfully tested in IMP and installed into the main accelerator ring of the complex. The RF station includes accelerating RF cavity and RF power generator with power supplies. The station works within frequency range 6.0 - 14.0 MHz, maximum voltage across the accelerating gap of the RF cavity - 20 kV. In the RF cavity the 200 VNP ferrite is utilized. A residual gas pressure in vacuum chamber does not exceed 2,5E-11 mbar. Maximum output power of the RF generator 25 kW. The data acquisition and control of the RF station is based on COMPACT - PCI bus and provides all functions of monitoring and control.

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

Energy Technology Data Exchange (ETDEWEB)

Hillairet, Julien, E-mail: julien.hillairet@cea.fr [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Argouarch, Arnaud [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Bamber, Rob [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Beaumont, Bertrand [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Bernard, Jean-Michel; Delaplanche, Jean-Marc [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Durodié, Frédéric [Laboratory for Plasmas Physics, 1000 Brussels (Belgium); Lamalle, Philippe [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Lombard, Gilles [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Nicholls, Keith; Shannon, Mark [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Vulliez, Karl [Maestral Laboratory, Technetics Group, Pierrelatte (France); Cantone, Vincent; Hatchressian, Jean-Claude; Larroque, Sébastien; Lebourg, Philippe; Martinez, André; Mollard, Patrick; Mouyon, David; Pagano, Marco [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); and others

2015-10-15

Highlights: • CEA have developed a dedicated test-bed for testing RF contact in ITER relevant conditions (vacuum, temperature, RF current). • A prototype of RF contacts have been designed and manufactured, with copper lamellas brazed on a titanium holder. • This RF contact prototype failed at RF current larger than 1.8 kA. • Extensive R&D is foreseen with new RF contact designs. - Abstract: 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 the machine. The contacts have to sustain a temperature up to 250 °C during 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 contacts have 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 (CYclotron CLuster for Europe), an R&D program has been conducted to develop RF contacts that meet the ITER ICRH launcher specifications. A design proposed by CYCLE consortium, using brazed lamellas supported by a spring to improve thermal exchange efficiency while guaranteeing high contact force, was tested successfully in the T-resonator up to 1.7 kA during 1200 s, but failed for larger current values due to a degradation of the contacts. Details concerning the manufacturing of the brazed contacts on its titanium holder, the RF tests results performed on the resonator and the non-destructive tests analysis of the contacts are given in this paper.

Land and Undersea Field Testing of Very Low Frequency RF Antennas and Loop Transceivers

Science.gov (United States)

2017-12-01

report presents experiments and findings for VLF RF communications using both commercial off-the-shelf (COTS) transceivers acquired from vendor...RF) communication in the ocean environment. This report presents experiments and findings for VLF RF communications using both commercial off the...work described in this report was performed for the Office of Naval Research (ONR) Forward Deployed Energy and Communications Outpost (FDECO) Innovative

Experimental study of rf pulsed heating

Directory of Open Access Journals (Sweden)

Lisa Laurent

2011-04-01

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

LAB3 Cosmic Ray Test Stand Analysis of Steel Stack Supports

International Nuclear Information System (INIS)

Cease, H.

1998-01-01

A cosmic ray test stand is being constructed at Lab 3. The stand consists of two stacks of steel plates one resting on top of the other. The top stack is composed of 6 plates of steel making an overall stack size of 34.5-inch x 40-inch x 99-inch. The bottom stack also has 6 layers of plate making an overall size of approximately 49.5-inch x 82-inch x 99-inch. The bottom stack is supported with three support legs. See drawing 3823.000ME-900428 for the individual plate orientation. The minimum support leg size and necessary welds between plates are determined.

Lasertron, a pulsed RF-source using laser triggered photocathode

International Nuclear Information System (INIS)

Yoshioka, Masakazu.

1988-12-01

A new pulsed RF-source, 'Lasertron', are being developed as a possible RF-power source for future electron-positron linear colliders. In a series of systematic study, a prototype lasertron has been fabricated and tested. A peak power of 80 kW is attained at 2.856 GHz RF-frequency in 1-μs time duration. This paper describes the experimental results of the lasertron including the developments of the photocathode and the laser system. Test results are compared with the analysis of beam dynamics in the lasertron. (author)

Introducing sit-stand desks increases classroom standing time among university students

Directory of Open Access Journals (Sweden)

Matthew Jerome

2017-12-01

Full Text Available Excessive sedentary behavior has been associated with many negative health outcomes. While an understudied health topic, there is evidence that university students are excessively sedentary. Sit-stand desks have been shown to reduce sedentary time among pre-university students (ages 5–18years and sedentary workers but have not been tested in university classrooms. This study tested the effects of introducing sit-stand desks into a university classroom on student's classroom sitting and standing behaviors. Using a cross-over design, students received access to both traditional seated desks and sit-stand desks for six weeks. Data were collected between September and December, 2016. We recruited 304 healthy undergraduate university students enrolled in one of two small (25 seats classrooms at a large Midwestern university during the fall of 2016. Average minutes of standing/hour/student, average percent class time spent standing, and the number of sit-stand transitions/student/hour were directly observed with video camera surveillance. Participants stood significantly more (p<0.001 when provided access to sit-stand desks (7.2min/h/student; 9.3% of class time spent standing compared to when they had access to seated desks (0.7min/h/student; 1.6% of class time spent standing but no differences were observed for the number of sit-stand transitions (p=0.47. Students reported high favorability for the sit-stand desks and improvements in several student engagement and affective outcomes while using the sit-stand desks. These findings support introducing sit-stand desks in university classrooms as an approach to reduce sedentary behaviors of university students. Keywords: Sedentary, University students, Sit-stand desk

rf coupler technology for fusion applications

International Nuclear Information System (INIS)

Hoffman, D.J.

1983-01-01

Radio frequency (rf) oscillations at critical frequencies have successfully provided a means to convey power to fusion plasmas due to the electrical-magnetic properties of the plasma. While large rf systems to couple power to the plasma have been designed, built, and tested, the main link to the plasma, the coupler, is still in an evolutionary stage of development. Design and fabrication of optimal antennas for fusion applications are complicated by incomplete characterizations of the harsh plasma environment and of coupling mechanisms. A brief description of rf coupler technology required for plasma conditions is presented along with an assessment of the status and goals of coupler development

A New 500-kV Ion Source Test Stand for HIF

International Nuclear Information System (INIS)

Sangster, T.C.; Ahle, L.E.; Halaxa, E.F.; Karpenko, V.P.; Oldaker, M. E.; Mitchell, J.W.; Beck, D.N.; Bieniosek, F.M.; Henestroza, E.; Kwan, J.W.

2000-01-01

One of the most challenging aspects of ion beam driven inertial fusion energy is the reliable and efficient generation of low emittance, high current ion beams. The primary ion source requirements include a rise time of order 1-msec, a pulse width of at least 20-msec, a flattop ripple of less than 0.1% and a repetition rate of at least 5-Hz. Naturally, at such a repetition rate, the duty cycle of the source must be greater than 108 pulses. Although these specifications do not appear to exceed the state-of-the-art for pulsed power, considerable effort remains to develop a suitable high current ion source. Therefore, we are constructing a 500-kV test stand specifically for studying various ion source concepts including surface, plasma and metal vapor arc. This paper will describe the test stand design specifications as well as the details of the various subsystems and components

Introducing sit-stand desks increases classroom standing time among university students.

Science.gov (United States)

Jerome, Matthew; Janz, Kathleen F; Baquero, Barbara; Carr, Lucas J

2017-12-01

Excessive sedentary behavior has been associated with many negative health outcomes. While an understudied health topic, there is evidence that university students are excessively sedentary. Sit-stand desks have been shown to reduce sedentary time among pre-university students (ages 5-18 years) and sedentary workers but have not been tested in university classrooms. This study tested the effects of introducing sit-stand desks into a university classroom on student's classroom sitting and standing behaviors. Using a cross-over design, students received access to both traditional seated desks and sit-stand desks for six weeks. Data were collected between September and December, 2016. We recruited 304 healthy undergraduate university students enrolled in one of two small (25 seats) classrooms at a large Midwestern university during the fall of 2016. Average minutes of standing/hour/student, average percent class time spent standing, and the number of sit-stand transitions/student/hour were directly observed with video camera surveillance. Participants stood significantly more (p classrooms as an approach to reduce sedentary behaviors of university students.

The JAERI superconducting RF linac-based FELS and THEIR cryogenics

International Nuclear Information System (INIS)

Minehara, Eisuke J.

2003-01-01

In the 21st century, we need a powerful and efficient free-electron laser (FEL) for academic and industrial uses in almost all fields. In order to realize such a tunable, highly-efficient, high average power, high peak power and ultra-short pulse FEL, the JAERI FEL group and I have developed an industrial FEL driven by a compact, stand-alone and zero-boil off super-conducting rf linac with an energy-recovery geometry. Our discussions on the JAERI FEL and cryogenics will cover market-requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil off cryostat concept and operational experiences over these 9 years, our discovery of the new, highly-efficient, high-power, and ultra-short pulse lasing mode, and the energy-recovery geometry. (author)

Detailed design of the RF source for the 1 MV neutral beam test facility

International Nuclear Information System (INIS)

Marcuzzi, D.; Palma, M. Dalla; Pavei, M.; Heinemann, B.; Kraus, W.; Riedl, R.

2009-01-01

In the framework of the EU activities for the development of the Neutral Beam Injector for ITER, the detailed design of the Radio Frequency (RF) driven negative ion source to be installed in the 1 MV ITER Neutral Beam Test Facility (NBTF) has been carried out. Results coming from ongoing R and D on IPP test beds [A. Staebler et al., Development of a RF-Driven Ion Source for the ITER NBI System, this conference] and the design of the new ELISE facility [B. Heinemann et al., Design of the Half-Size ITER Neutral Beam Source Test Facility ELISE, this conference] brought several modifications to the solution based on the previous design. An assessment was carried out regarding the Back-Streaming positive Ions (BSI+) that impinge on the back plates of the ion source and cause high and localized heat loads. This led to the redesign of most heated components to increase cooling, and to different choices for the plasma facing materials to reduce the effects of sputtering. The design of the electric circuit, gas supply and the other auxiliary systems has been optimized. Integration with other components of the beam source has been revised, with regards to the interfaces with the supporting structure, the plasma grid and the flexible connections. In the paper the design will be presented in detail, as well as the results of the analyses performed for the thermo-mechanical verification of the components.

Guidance on the Stand Down, Mothball, and Reactivation of Ground Test Facilities

Science.gov (United States)

Volkman, Gregrey T.; Dunn, Steven C.

2013-01-01

The development of aerospace and aeronautics products typically requires three distinct types of testing resources across research, development, test, and evaluation: experimental ground testing, computational "testing" and development, and flight testing. Over the last twenty plus years, computational methods have replaced some physical experiments and this trend is continuing. The result is decreased utilization of ground test capabilities and, along with market forces, industry consolidation, and other factors, has resulted in the stand down and oftentimes closure of many ground test facilities. Ground test capabilities are (and very likely will continue to be for many years) required to verify computational results and to provide information for regimes where computational methods remain immature. Ground test capabilities are very costly to build and to maintain, so once constructed and operational it may be desirable to retain access to those capabilities even if not currently needed. One means of doing this while reducing ongoing sustainment costs is to stand down the facility into a "mothball" status - keeping it alive to bring it back when needed. Both NASA and the US Department of Defense have policies to accomplish the mothball of a facility, but with little detail. This paper offers a generic process to follow that can be tailored based on the needs of the owner and the applicable facility.

RF current distribution and topology of RF sheath potentials in front of ICRF antennae

International Nuclear Information System (INIS)

Colas, L.; Heuraux, S.; Bremond, S.; Bosia, G.

2005-01-01

The 2D (radial/poloidal) spatial topology of RF-induced convective cells developing radially in front of ion cyclotron range of frequency (ICRF) antennae is investigated, in relation to the spatial distribution of RF currents over the metallic structure of the antenna. This is done via a Green's function, determined from the ICRF wave coupling equations, and well-suited to open field lines extending toroidally far away on both sides of the antenna. Using such formalism, combined with a full-wave calculation using the 3D antenna code ICANT (Pecoul S. et al 2000 Comput. Phys. Commun. 146 166-87), two classes of convective cells are analysed. The first one appears in front of phased arrays of straps, and depending on the strap phasing, its topology is interpreted using the poloidal profiles of either the RF current or the RF voltage of the strip line theory. The other class of convective cells is specific to antenna box corners and is evidenced for the first time. Based on such analysis, general design rules are worked out in order to reduce the RF-sheath potentials, which generalize those proposed in the earlier literature, and concrete antenna design options are tested numerically. The merits of aligning all strap centres on the same (tilted) flux tube, and of reducing the antenna box toroidal conductivity in its lower and upper parts, are discussed

HISTRAP [Heavy Ion Storage Ring for Atomic Physics] vacuum test stand for pressures of 10-12 Torr

International Nuclear Information System (INIS)

Johnson, J.W.; Atkins, W.H.; Dowling, D.T.; McConnell, J.W.; Milner, W.T.; Olsen, D.K.

1988-01-01

HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed synchrotron/cooler/storage ring accelerator optimized for advanced atomic physics research. The ring has a circumference of 46.8 m, a bore diameter of about 15 cm, and requires a vacuum of 10 -12 Torr in order to decelerate highly-charged very-heavy ions down to low energies. To be able to test components and procedures to achieve this pressure, a test stand approximately modeling one-sixteenth of the ring vacuum chamber has been built. The 3.5-m-long test stand has been fabricated from 10-cm-diameter components, with 316LN stainless steel flanges. Prior to assembly, these components were vacuum fired at 950/degree/C at a pressure of 10 -4 Torr. The test stand is bakeable in situ at 300/degree/C. Pumping is achieved with two 750-L/s titanium sublimator pumps and one 60-L/s ion pump. Pressure is measured with two extractor ion gauges and a 10 -14 PP RGA. The roughing for the test stand consists of cryosorption pumps followed by a cryopump. A pressure of 4 x 10 -12 Torr has been achieved. 7 refs., 5 figs

Beam Dynamics Simulation of Photocathode RF Electron Gun at the PBP-CMU Linac Laboratory

Science.gov (United States)

Buakor, K.; Rimjaem, S.

2017-09-01

Photocathode radio-frequency (RF) electron guns are widely used at many particle accelerator laboratories due to high quality of produced electron beams. By using a short-pulse laser to induce the photoemission process, the electrons are emitted with low energy spread. Moreover, the photocathode RF guns are not suffered from the electron back bombardment effect, which can cause the limited electron current and accelerated energy. In this research, we aim to develop the photocathode RF gun for the linac-based THz radiation source. Its design is based on the existing gun at the PBP-CMU Linac Laboratory. The gun consists of a one and a half cell S-band standing-wave RF cavities with a maximum electric field of about 60 MV/m at the centre of the full cell. We study the beam dynamics of electrons traveling through the electromagnetic field inside the RF gun by using the particle tracking program ASTRA. The laser properties i.e. transverse size and injecting phase are optimized to obtain low transverse emittance. In addition, the solenoid magnet is applied for beam focusing and emittance compensation. The proper solenoid magnetic field is then investigated to find the optimum value for proper emittance conservation condition.

ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS

Energy Technology Data Exchange (ETDEWEB)

Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

2010-05-12

In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

Mechanical Design, Simulation, and Testing of Self-Aligning Gaussian Telescope and Stand for ITER LFS Reflectometer Diagnostic

Science.gov (United States)

Broughton, Rachel; Gomez, Michael; Zolfaghari, Ali; Morris, Lewis

2016-10-01

A self-aligning Gaussian telescope has been designed to compensate for the effect of movement in the ITER vacuum vessel on the transmission line. The purpose of the setup is to couple microwaves into and out of the vessel across the vacuum windows while allowing for both slow movements of the vessel, due to thermal growth, and rapid movements, due to vibrations and disruptions. Additionally, a test stand has been designed specifically to hold this telescope in order to imitate these movements. Consequently, this will allow for the assessment of the efficacy in applying the self-aligning Gaussian telescope approach. The motions of the test stand, as well as the stress on the telescope mechanism, have been virtually simulated using ANSYS workbench. A prototype of this test stand and self-aligning telescope will be built using a combination of custom machined parts and ordered parts. The completed mechanism will be tested at the lab in four different ways: slow single- and multi-direction movements, rapid multi-direction movement, functional laser alignment and self-aligning tests, and natural frequency tests. Once the prototype successfully passes all requirements, it will be tested with microwaves in the LFSR transmission line test stand at General Atomics. This work is supported by US DOE Contract No. DE-AC02-09CH11466.

Hip Strength Testing of Soccer Players With Long-Standing Hip and Groin Pain: What are the Clinical Implications of Pain During Testing?

Science.gov (United States)

Rafn, Bolette S; Tang, Lars; Nielsen, Martin P; Branci, Sonia; Hölmich, Per; Thorborg, Kristian

2016-05-01

To investigate whether self-reported pain during hip strength testing correlates to a large degree with hip muscle strength in soccer players with long-standing unilateral hip and groin pain. Cross-sectional study. Clinical assessments at Sports Orthopaedic Research Center-Copenhagen (SORC-C), Arthroscopic Centre Amager, Copenhagen University Hospital, Denmark. Twenty-four male soccer players with unilateral long-standing hip and groin pain. The soccer players performed 5 reliable hip muscle strength tests (isometric hip flexion, adduction, abduction, isometric hip flexion-modified Thomas test, and eccentric hip adduction). Muscle strength was measured with a hand-held dynamometer, and the players rated the pain during testing on a numerical rating scale (0-10). In 4 tests (isometric hip adduction, abduction, flexion, and eccentric adduction), no significant correlations were found between pain during testing and hip muscle strength (Spearman rho = -0.28 to 0.06, P = 0.09-0.39). Isometric hip flexion (modified Thomas test position) showed a moderate negative correlation between pain and hip muscle strength (Spearman rho = -0.44, P = 0.016). Self-reported pain during testing does not seem to correlate with the majority of hip muscle strength tests used in soccer players with long-standing hip and groin pain.

High power testing oa ANL X-band dielectric-loaded accelerating structures

International Nuclear Information System (INIS)

Power, J. G.; Gai, W.; Jing, C.; Konecny, R.; Gold, S. H.; Kinkead, A. K.

2002-01-01

In the second phase of a program to develop a compact accelerator based on a dielectric-loaded accelerating structure, we have conducted high power tests on a traveling-wave and a standing-wave prototype. Indications are that the traveling-wave structure achieved an accelerating gradient of 3-5 MV/m before the input coupling window failed, while the standing wave structure was poorly matched at high power due to contamination of copper residue on its coupling window. To solve both of these problems, a new method for coupling RF into the structures has been developed. The new couplers and the rest of the modular structure are currently under construction and will be tested at the Naval Research Laboratory shortly

Test and diagnosis of analogue, mixed-signal and RF integrated circuits the system on chip approach

CERN Document Server

Sun, Yichuang

2008-01-01

This book provides a comprehensive discussion of automatic testing, diagnosis and tuning of analogue, mixed-signal and RF integrated circuits, and systems in a single source. The book contains eleven chapters written by leading researchers worldwide. As well as fundamental concepts and techniques, the book reports systematically the state of the arts and future research directions of these areas. A complete range of circuit components are covered and test issues are also addressed from the SoC perspective.

Reliability and sensitivity to change of the timed standing balance test in children with down syndrome

Directory of Open Access Journals (Sweden)

Vencita Priyanka Aranha

2016-01-01

Full Text Available Objective: To estimate the reliability and sensitivity to change of the timed standing balance test in children with Down syndrome (DS. Methods: It was a nonblinded, comparison study with a convenience sample of subjects consisting of children with DS (n = 9 aged 8–17 years. The main outcome measure was standing balance which was assessed using timed standing balance test, the time required to maintain in four conditions, eyes open static, eyes closed static, eyes open dynamic, and eyes closed dynamic. Results: Relative reliability was excellent for all four conditions with an Interclass Correlation Coefficient (ICC ranging from 0.91 to 0.93. The variation between repeated measurements for each condition was minimal with standard error of measurement (SEM of 0.21–0.59 s, suggestive of excellent absolute reliability. The sensitivity to change as measured by smallest real change (SRC was 1.27 s for eyes open static, 1.63 s for eyes closed static, 0.58 s for eyes open dynamic, and 0.61 s for eyes closed static. Conclusions: Timed standing balance test is an easy to administer test and sensitive to change with strong absolute and relative reliabilities, an important first step in establishing its utility as a clinical balance measure in children with DS.

Development of Infrastructure Facilities for Superconducting RF Cavity Fabrication, Processing and 2 K Characterization at RRCAT

Science.gov (United States)

Joshi, S. C.; Raghavendra, S.; Jain, V. K.; Puntambekar, A.; Khare, P.; Dwivedi, J.; Mundra, G.; Kush, P. K.; Shrivastava, P.; Lad, M.; Gupta, P. D.

2017-02-01

An extensive infrastructure facility is being established at Raja Ramanna Centre for Advanced Technology (RRCAT) for a proposed 1 GeV, high intensity superconducting proton linac for Indian Spallation Neutron Source. The proton linac will comprise of a large number of superconducting Radio Frequency (SCRF) cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. Infrastructure facilities for SCRF cavity fabrication, processing and performance characterization at 2 K are setup to take-up manufacturing of large number of cavities required for future projects of Department of Atomic Energy (DAE). RRCAT is also participating in a DAE’s approved mega project on “Physics and Advanced technology for High intensity Proton Accelerators” under Indian Institutions-Fermilab Collaboration (IIFC). In the R&D phase of IIFC program, a number of high beta, fully dressed multi-cell elliptical SCRF cavities will be developed in collaboration with Fermilab. A dedicated facility for SCRF cavity fabrication, tuning and processing is set up. SCRF cavities developed will be characterized at 2K using a vertical test stand facility, which is already commissioned. A Horizontal Test Stand facility has also been designed and under development for testing a dressed multi-cell SCRF cavity at 2K. The paper presents the infrastructure facilities setup at RRCAT for SCRF cavity fabrication, processing and testing at 2K.

Imaging performance of a dedicated radiation transparent RF coil on a 1.0 Tesla inline MRI-linac.

Science.gov (United States)

Liney, Gary P; Dong, Bin; Weber, Ewald; Rai, Robba; Destruel, Aurelien; Garcia-Alvarez, Roberto; Manton, David; Jelen, Urszula; Zhang, Kevin; Barton, Michael; Keall, Paul J; Crozier, Stuart

2018-05-25

This work describes the first imaging studies on a 1.0 Tesla inline MRI-Linac using a dedicated transmit/receive RF body coil that has been designed to be completely radio transparent and provide optimum imaging performance over a large patient opening. Methods: A series of experiments was performed on the MRI-Linac to investigate the performance and imaging characteristics of a new dedicated volumetric RF coil: (1) numerical electromagnetic simulations were used to measure transmit efficiency in two patient positions; (2) image quality metrics of signal-to-noise ratio (SNR), ghosting and uniformity were assessed in a large diameter phantom with no radiation beam; (3) radiation induced effects were investigated in both the raw data (k-space) and image sequences acquired with simultaneous irradiation; (4) radiation dose was measured with and without image acquisition; (5) RF heating was studied using an MR-compatible fluoroptic thermometer and; (6) the in vivo image quality and versatility of the coil was demonstrated in normal healthy subjects for both supine and standing positions. Results: Daily phantom measurements demonstrated excellent imaging performance with stable SNR over a period of 3 months (42.6 ± 0.9). Simultaneous irradiation produced no statistical change in image quality (p>0.74) and no interference in raw data for a 20  20 cm radiation field. The coil was found to be efficient over large volumes and negligible RF heating was observed. Volunteer scans acquired in both supine and standing positions provided artefact free images with good anatomical visualisation. Conclusions: The first completely radio transparent RF coil for use on a 1.0 Tesla MRI-Linac has been described. There is no impact on either the imaging or dosimetry performance with a simultaneous radiation beam. The open design enables imaging and radiotherapy guidance in a variety of positons. . © 2018 Institute of Physics and Engineering in Medicine.

Superconducting rf activities at Cornell University

International Nuclear Information System (INIS)

Padamsee, H.; Hakimi, M.; Kirchgessner, J.

1988-01-01

Development of rf superconductivity for high energy accelerators has been a robust activity at the Cornell Laboratory of Nuclear Studies (LNS) for many years. In order to realize the potential of rf superconductivity, a two-pronged approach has been followed. On the one hand accelerator applications were selected where the existing state-of-the art of superconducting rf is competitive with alternate technologies, then LNS engaged in a program to design, construct and test suitable superconducting cavities, culminating in a full system test in an operating accelerator. On the second front the discovery and invention of ideas, techniques and materials required to make superconducting rf devices approach the ideal in performance has been aggressively pursued. Starting with the development of superconducting cavities for high energy electron synchrotrons, the technology was extended to high energy e + e - storage rings. The LE5 cavity design has now been adopted for use in the Continuous Electron Beam Accelerator Facility (CEBAF). When completed, this project will be one of the largest applications of SRF technology, using 440 LE5 modules[4]. In the last two years, the cavity design and the technology have been transferred to industry and CEBAF. Cornell has tested the early industrial prototypes and cavity pairs. LNS has developed, in collaboration with CEBAF, designs and procedures for cavity pair and cryomodule assembly and testing. Advanced research for future electron accelerators is badly needed if particle physicists hope to expand the energy frontier. Superconducting cavity technology continues to offer attractive opportunities for further advances in achievable voltage at reasonable cost for future accelerators. For Nb, the full potential implies an order of magnitude increase over current capabilities. 20 references, 11 figures

Design study of an S-band RF cavity of a dual-energy electron LINAC for the CIS

Science.gov (United States)

Lee, Byeong-No; Park, Hyungdal; Song, Ki-baek; Li, Yonggui; Lee, Byung Cheol; Cha, Sung-su; Lee, Jong-Chul; Shin, Seung-Wook; Chai, Jong-seo

2014-01-01

The design of a resonance frequency (RF) cavity for the dual-energy S-band electron linear accelerator (LINAC) has been carried out for the cargo inspection system (CIS). This Standing-wave-type RF cavity is operated at a frequency under the 2856-MHz resonance frequency and generates electron beams of 9 MeV (high mode) and 6 MeV (low mode). The electrons are accelerated from the initial energy of the electron gun to the target energy (9 or 6 MeV) inside the RF cavity by using the RF power transmitted from a 5.5-MW-class klystron. Then, electron beams with a 1-kW average power (both high mode and low mode) bombard an X-ray target a 2-mm spot size. The proposed accelerating gradient was 13 MV/m, and the designed Q value was about 7100. On going research on 15-MeV non-destructive inspections for military or other applications is presented.

Measurement by a cylinder test stand and tyre rolling resistance

Directory of Open Access Journals (Sweden)

A. Dávid

2006-03-01

Full Text Available Sometimes it is necessary to test how repair affects the properties of the car. These tests are carried out using a cylinder test stand. During the test the tyre is rolling between two cylinders of a small diameter. The question arises whether the rolling resistance of the tyre is the same as the rolling resistance when the wheel is rolling on the plane. If it is not the same what is the reliation between tyre resistances in these two cases? It is an important answer because the change of rolling resistance can affect consumption, the highest speed, engine power and other results of measurement. The paper gives the answer to these questions and describes the method of getting this information.

Design of a 5 GHz window in a lower hybrid r.f. system

International Nuclear Information System (INIS)

Maebara, S.; Ikeda, Y.; Seki, M.; Imai, T.

1995-01-01

A new pill-box window at a frequency of 5GHz, which has an oversized length in both the axial and the radial direction, has been designed to reduce the r.f. power density and the electric field strength at the ceramics. The dimension of the new pill-box is optimized from the numerical calculation and a voltage standing-wave ratio of less than 1.02 is obtained. The r.f. power density and the maximum electric field strength are reduced to about 40% and 66% of the standard pill-box window respectively. It is evaluated that the power capability of the new oversized pill-box window by cooling edge of ceramics is more than 500kW with continuous-wave operation. ((orig.))

RF-MEMS for future mobile applications: experimental verification of a reconfigurable 8-bit power attenuator up to 110 GHz

International Nuclear Information System (INIS)

Iannacci, J; Tschoban, C

2017-01-01

RF-MEMS technology is proposed as a key enabling solution for realising the high-performance and highly reconfigurable passive components that future communication standards will demand. In this work, we present, test and discuss a novel design concept for an 8-bit reconfigurable power attenuator, manufactured using the RF-MEMS technology available at the CMM-FBK, in Italy. The device features electrostatically controlled MEMS ohmic switches in order to select/deselect the resistive loads (both in series and shunt configuration) that attenuate the RF signal, and comprises eight cascaded stages (i.e. 8-bit), thus implementing 256 different network configurations. The fabricated samples are measured (S-parameters) from 10 MHz to 110 GHz in a wide range of different configurations, and modelled/simulated with Ansys HFSS. The device exhibits attenuation levels (S21) in the range from  −10 dB to  −60 dB, up to 110 GHz. In particular, S21 shows flatness from 15 dB down to 3–5 dB and from 10 MHz to 50 GHz, as well as fewer linear traces up to 110 GHz. A comprehensive discussion is developed regarding the voltage standing wave ratio, which is employed as a quality indicator for the attenuation levels. The margins of improvement at design level which are needed to overcome the limitations of the presented RF-MEMS device are also discussed. (paper)

Addressing challenges to MMPI-2-RF-based testimony: questions and answers.

Science.gov (United States)

Ben-Porath, Yossef S

2012-11-01

Introduction of a new version of a psychological test brings with it challenges that can be accentuated by the adversarial nature of the legal process. In the case of the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF), these challenges can be addressed by becoming familiar with the rationale for and the methods used in revising the inventory, the information contained in the test manuals, and the growing peer-reviewed literature on the test. Potential challenges to MMPI-2-RF-based testimony are identified in this article and discussed in question and answer format. The questions guiding this discussion are based on the Daubert factors, established in 1993 by the US Supreme Court as criteria for gauging the scientific validity of proffered expert testimony. The answers to these questions apply more broadly to testimony in depositions, pre-trial hearings, and at trial. Consideration of the MMPI-2-RF in light of the Daubert factors indicates that the instrument has been subjected to extensive empirical testing and that a substantial peer-reviewed literature is available to guide and support its use. Information about the known and potential rate of error associated with MMPI-2-RF scores is available, and standard procedures for administration, scoring, and interpretation of the inventory are detailed in the test administration manual. Indicators of MMPI-2-RF acceptance can be cited, and criticisms of the MMPI-2-RF can be addressed with information available in the test documents and an extensive, modern, and actively growing peer-reviewed literature.

Testing of inductive output tube based RF amplifier for 650 MHz SRF cavities

International Nuclear Information System (INIS)

Mandal, A.; Som, S.; Manna, S.K.; Ghosh, S.; Seth, S.; Thakur, S.K.; Saha, S.; Panda, U.S.

2012-01-01

A 650 MHz IOT based RF amplifier has been developed in VECC. It can be used to power several cavity modules in high energy high current proton linear accelerator to be built for ADSS programme in India and in Project-X at Fermilab, USA. The IOT based amplifier requires different powers supplies, water cooling and forced air cooling for its operation. A Programmable Logic Controller (PLC) based interlocks has been incorporated to take care of systematic on/off of the power supplies and driver amplifier, water flow, air flow and other interlocks for the safe operation of the RF System. In addition to that EPICS based RF operating console and data logging/monitoring system has been added. (author)

Design of test kits for the RF characterization of the PAM antenna of LHCD system for Aditya-upgrade Tokamak

International Nuclear Information System (INIS)

Jain, Yogesh M.; Sharma, P.K.; Parmar, P.R.; Ambulkar, K.K.

2017-01-01

The Lower Hybrid Current Drive (LHCD) system of the ADITYA-Upgrade tokamak will employ a Passive Active Multijunction (PAM) antenna to launch 250 kW of RF power at 3.7 GHz to drive plasma current non inductively in the tokamak. To evaluate the RF performance of the designed PAM antenna, it is characterized with the help of VNA measurements. The performance of the PAM antenna is mainly decided by the integrated performance of the entire antenna (with a differential phase shift of 270° and equal power distribution between each of the output waveguides) and the performance of mode converter, which transforms input TE 10 mode to TE 30 mode (with a mode purity of 98.5% at the output). This poster thus reports the design and analysis of these testing kits. Also, the test results of PAM antenna obtained by using these test kits would also be presented and discussed in this poster

Development of 650 MHz solid state RF amplifier for proton accelerator

International Nuclear Information System (INIS)

Jain, Akhilesh; Sharma, Deepak; Gupta, Alok; Tiwari, Ashish; Rao, Nageswar; Sekar, Vasanthi; Lad, M.; Hannurkar, P.R.; Gupta, P.D.

2011-01-01

Design and development of 30 kW high powers RF source at 650 MHz, using solid RF state technology, has been initiated at RRCAT. The indigenous technology development efforts will be useful for the proposed high power proton accelerators for SNS/ADS applications. In this 650 MHz amplifier scheme, 30 kW CW RF power will be generated using modular combination of 8 kW amplifier units. Necessary studies were carried out for device selection, choice of amplifier architecture and design of high power combiners and dividers. Presently RF amplifier delivering 250 W at 650 MHz has been fabricated and tested. Towards development of high power RF components, design and engineering prototyping of 16-port power combiner, directional coupler and RF dummy loads has been completed. The basic 8 kW amplifier unit is designed to provide power gain of 50 dB, bandwidth of 20 MHz and spurious response below 30 dB from fundamental signal. Based on the results of circuit simulation studies and engineering prototyping of amplifier module, two RF transistor viz. MRF3450 and MRF 61K were selected as solid state active devices. Impedance matching network in amplifier module is designed using balanced push pull configuration with transmission line BALUN. Due to high circulating current near drain side, metal clad RF capacitors were selected which helps in avoiding hot spot from output transmission path, ensuring continuous operation at rated RF power without damage to RF board. 350 W circulator is used to protect the RF devices from reflected power. Based on the prototype design and measured performance, one of these RF transistors will be selected to be used as workhorse for all amplifier modules. Two amplifier modules are mounted on water cooled copper heat-sink ensuring proper operating temperature for reliable and safe operation of amplifier. Also real time control system and data logger has been developed to provide DAQ and controls in each rack. For power combining and power measurement

Brookhaven National Laboratory electron beam test stand

International Nuclear Information System (INIS)

Pikin, A.; Alessi, J.; Beebe, E.; Kponou, A.; Prelec, K.; Snydstrup, L.

1998-01-01

The main purpose of the electron beam test stand (EBTS) project at the Brookhaven National Laboratory is to build a versatile device to develop technologies that are relevant for a high intensity electron beam ion source (EBIS) and to study the physics of ion confinement in a trap. The EBTS will have all the main attributes of EBIS: a 1-m-long, 5 T superconducting solenoid, electron gun, drift tube structure, electron collector, vacuum system, ion injection system, appropriate control, and instrumentation. Therefore it can be considered a short prototype of an EBIS for a relativistic heavy ion collider. The drift tube structure will be mounted in a vacuum tube inside a open-quotes warmclose quotes bore of a superconducting solenoid, it will be at room temperature, and its design will employ ultrahigh vacuum technology to reach the 10 -10 Torr level. The first gun to be tested will be a 10 A electron gun with high emission density and magnetic compression of the electron beam. copyright 1998 American Institute of Physics

Design of The Test Stand for Hydraulic Active Heave Compensation System

Directory of Open Access Journals (Sweden)

Jakubowski Arkadiusz

2017-01-01

Full Text Available The article presented here described the design of a test stand for hydraulic active heave compensation system. The simulation of sea waves is realized by the use of hydraulic cylinder. A hydraulic motor is used for sea waves compensation. The hydraulic cylinder and the hydraulic motor are controlled by electrohydraulic servo valves. For the measurements Authors used displacement sensor and incremental encoder. Control algorithm is implemented on the PLC. The performed tests included hydraulic actuator and hydraulic motor step responses.

Development of low emittance high brightness electron beams and rf accelerating structures

International Nuclear Information System (INIS)

Pellegrini, C.

1991-01-01

The main goals of this project were the construction of an S-band RF photoinjector for the production of a high brightness electron beam, and the development of a new type of RF accelerator structure; the Plane wave transformer. By the end of October 1991 the photoinjector had been built, its RF characteristics had been measured at low power, and an initial test of the gun at high RF power had been done. The Plane Wave Transformer had also been built and tested at lower power. In both cases the results obtained are mostly in agreement with the expected and calculated behavior

THE COMPLEX OF STANDS FOR TESTING THE AIR CUSHION CHASSIS OF AIRCRAFT AND VEHICLES

Directory of Open Access Journals (Sweden)

2016-01-01

Full Text Available This article deals with a set of stands made in NIMK TSAGI for testing and creating the air cushion chassis for the aircraft and vehicles. It allows to fully embrace the process of developing and constructing the air cushion chassis for air- craft and solve problems relating to peculiarities of such aircraft on the takeoff, landing and movement in the elementary prepared and unprepared soil runways, flat terrain and water areas. The complex includes: the experimental installation to study aeroelasticity phenomena of the chassis in the extending and retracting process with simulation of aircraft and ekran- oplane takeoff and landing modes in the air flow, including the wind tunnels; the experimental stand with vertical screen for testing of ekranoplane models in T-5 wind tunnel of NIMC TsAGI, permitting to simultaneously vary the model’s posi- tion relatively to the screen, roll, pitch (angle of attack, and banking; mobile experimental stand with contact crawler gear, for experimental determination and comparative evaluation of the chassis with different patterns of formation and air cush- ion fences for all-year-round testing in natural conditions at elementary-prepared and unprepared sites and water areas. Based on mathematical simulation of flow past in the wind tunnel the possibility of use booth stand with vertical screen and experimental installation to study aeroelasticity phenomena of the chassis for experimental studies, respectively, by defini- tion of the aerodynamic characteristics of forces and moments of the air cushion aircraft and ekranoplanes models and the research of phenomena of aeroelasticity of flexible fencing is substantiated.

Cryomdoule Test Stand Reduced-Magnetic Support Design at Fermilab

Energy Technology Data Exchange (ETDEWEB)

McGee, Mike [Fermilab; Chandrasekaran, Saravan Kumar [Fermilab; Crawford, Anthony [Fermilab; Harms, Elvin [Fermilab; Leibfritz, Jerry [Fermilab; Wu, Genfa [Fermilab

2016-06-01

In a partnership with SLAC National Accelerator Laboratory (SLAC) and Jefferson Lab, Fermilab will assemble and test 17 of the 35 total 1.3 GHz cryomodules for the Linac Coherent Light Source II (LCLS-II) Project. These devices will be tested at Fermilab's Cryomodule Test Facility (CMTF) within the Cryomodule Test Stand (CMTS-1) cave. The problem of magnetic pollution became one of major issues during design stage of the LCLS-II cryomodule as the average quality factor of the accelerating cavities is specified to be 2.7 x 10¹⁰. One of the possible ways to mitigate the effect of stray magnetic fields and to keep it below the goal of 5 mGauss involves the application of low permeable materials. Initial permeability and magnetic measurement studies regarding the use of 316L stainless steel material indicated that cold work (machining) and heat affected zones from welding would be acceptable.

1.5 MW RF Load for ITER

International Nuclear Information System (INIS)

Ives, Robert Lawrence; Marsden, David; Collins, George; Karimov, Rasul; Mizuhara, Max; Neilson, Jeffrey

2016-01-01

Calabazas Creek Research, Inc. developed a 1.5 MW RF load for the ITER fusion research facility currently under construction in France. This program leveraged technology developed in two previous SBIR programs that successfully developed high power RF loads for fusion research applications. This program specifically focused on modifications required by revised technical performance, materials, and assembly specification for ITER. This program implemented an innovative approach to actively distribute the RF power inside the load to avoid excessive heating or arcing associated with constructive interference. The new design implemented materials and assembly changes required to meet specifications. Critical components were built and successfully tested during the program.

1.5 MW RF Load for ITER

Energy Technology Data Exchange (ETDEWEB)

Ives, Robert Lawrence [Calabazas Creek Research, Inc., San Mateo, CA (United States); Marsden, David [Calabazas Creek Research, Inc., San Mateo, CA (United States); Collins, George [Calabazas Creek Research, Inc., San Mateo, CA (United States); Karimov, Rasul [Calabazas Creek Research, Inc., San Mateo, CA (United States); Mizuhara, Max [Calabazas Creek Research, Inc., San Mateo, CA (United States); Neilson, Jeffrey [Lexam Research, Redwood City, CA (United States)

2016-09-01

Calabazas Creek Research, Inc. developed a 1.5 MW RF load for the ITER fusion research facility currently under construction in France. This program leveraged technology developed in two previous SBIR programs that successfully developed high power RF loads for fusion research applications. This program specifically focused on modifications required by revised technical performance, materials, and assembly specification for ITER. This program implemented an innovative approach to actively distribute the RF power inside the load to avoid excessive heating or arcing associated with constructive interference. The new design implemented materials and assembly changes required to meet specifications. Critical components were built and successfully tested during the program.

Progress on a prototype main ring rf cavity

International Nuclear Information System (INIS)

Swain, G.; Kandarian, R.; Thiessen, H.A.; Poirier, R.; Smythe, W.R.

1989-01-01

A prototype rf cavity and rf drive system for a hadron facility main ring has been designed and will be tested in the Proton Storage Ring (PSR) at Los Alamos as a part of a collaborative effort between LANL and TRIUMF. The cavity uses an orthogonally biased ferrite tuner. The design provides for accelerating gap voltages up to 200 kV for the 49.3 to 50.8 MHz range. Progress on the cavity construction and testing is described. 13 refs., 5 figs

rf beam-current, -phase, and -position monitors

International Nuclear Information System (INIS)

Young, L.

1984-01-01

A prototype rf beam monitor has been tested on the Racetrack Microtron's (RTM) 100 kV injector beam line at the National Bureau of Standards (NBS). This beam monitor is capable of measuring the current, the relative phase, and the position of the beam. The beam is bunched at 2380 MHz for acceleration by the linac in the injector beam line. This train of beam bunches passing through the beam monitor cavities excites the cavities at this resonance frequency of 2380 MHz. Probes in the cavities couple some of the beam-excited rf power out of the cavities. This rf power can be amplified if necessary and then analyzed by a double balanced mixer (DBM). The DBM can also be used as a phase detector. The effective shunt impedance of the cavities was measured with the CW beam. For the position monitor cavity, the shunt impedance is proportional to the displacement from the axis. The measured response of the prototype rf beam current monitor setup is a linear function of beam current. Response of the rf beam-position monitor is also shown

Very long pulse high-RF power test of a lower hybrid frequency antenna module

International Nuclear Information System (INIS)

Goniche, M.; Brossaud, J.; Barral, C.; Berger-By, G.; Bibet, Ph.; Poli, S.; Rey, G.; Tonon, G.; Seki, M.; Obara, K.

1994-03-01

Outgassing, induced by very long RF waves injection at high power density was studied in a module, able to be used for a lower hybrid frequency antenna. Good RF properties of the module are reported, however, resonance phenomena with strong absorption of RF power (15%) was observed at high temperature (T>400 deg C). A large outgassing data base is provided by the 75 shots cumulating 27 hours of RF injection. The comparison with previous experiments (Tore Supra and TdV prototype modules) confirm the effect of baking and results are consistent. Outgassing increases exponentially with -1/T, and a desorption model with an activation energy Ed ∼ 0.35 eV fits the data up to 400 deg C. In order to design vacuum pumping system for large lower hybrid frequency antenna, outgassing rates are given for different working temperatures. (author). 11 refs., 55 figs

Very long pulse high-RF power test of a lower hybrid frequency antenna module

Energy Technology Data Exchange (ETDEWEB)

Goniche, M; Brossaud, J; Barral, C; Berger-By, G; Bibet, Ph; Poli, S; Rey, G; Tonon, G [Association Euratom-CEA, Centre d` Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Seki, M; Obara, K [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; and others

1994-03-01

Outgassing, induced by very long RF waves injection at high power density was studied in a module, able to be used for a lower hybrid frequency antenna. Good RF properties of the module are reported, however, resonance phenomena with strong absorption of RF power (15%) was observed at high temperature (T>400 deg C). A large outgassing data base is provided by the 75 shots cumulating 27 hours of RF injection. The comparison with previous experiments (Tore Supra and TdV prototype modules) confirm the effect of baking and results are consistent. Outgassing increases exponentially with -1/T, and a desorption model with an activation energy Ed {approx} 0.35 eV fits the data up to 400 deg C. In order to design vacuum pumping system for large lower hybrid frequency antenna, outgassing rates are given for different working temperatures. (author). 11 refs., 55 figs.

RF transport

International Nuclear Information System (INIS)

Choroba, Stefan

2013-01-01

This paper deals with the techniques of transport of high-power radiofrequency (RF) power from a RF power source to the cavities of an accelerator. Since the theory of electromagnetic waves in waveguides and of waveguide components is very well explained in a number of excellent text books it will limit itself on special waveguide distributions and on a number of, although not complete list of, special problems which sometimes occur in RF power transportation systems. (author)

Special MAFIA postprocessors for the analysis of RF structures

International Nuclear Information System (INIS)

Browman, M.J.

1992-01-01

This paper describes three stand-alone programs that use the electromagnetic fields generated by the MAFIA 2.04 codes to analyze radio-frequency (RF) cavities. Illustrations are provided that show how these codes are used to analyze the effect of the coupling slots on the electric and magnetic fields of the linacs for the APLE Prototype Experiment (APEX) and the Advanced Free-Electron Laser (AFEL); verify the Panofsky-Wenzel theorem for a high-energy deflecting cavity proposed for the Accelerator Transmutation of Waste (ATW) project; and study the effectiveness of that deflecting cavity. (Author) 10 refs., 4 figs

Special MAFIA postprocessors for the analysis of rf structures

International Nuclear Information System (INIS)

Browman, M.J.

1992-01-01

This paper describes three stand-alone programs that use the electromagnetic fields generated by the MAFIA 2.04 codes to analyze radio-frequency (RF) cavities. Illustrations are provided that show how these codes are used to (1) analyze the effect of the coupling slots on the electric and magnetic fields of the linacs for the APLE Prototype Experiment (APEX) and the Advanced Free-Electron Laser (AFEL), (2) verify the Panofsky-Wenzel theorem for a high-energy deflecting cavity proposed for the Accelerator Transmutation of Waste (ATW) project, and (3) study the effectiveness of that deflecting cavity

High power RF systems for the BNL ERL project

Energy Technology Data Exchange (ETDEWEB)

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.

Cryogenic infrastructure for Fermilab's ILC vertical cavity test facility

International Nuclear Information System (INIS)

Carcagno, R.; Ginsburg, C.; Huang, Y.; Norris, B.; Ozelis, J.; Peterson, T.; Poloubotko, V.; Rabehl, R.; Sylvester, C.; Wong, M.; Fermilab

2006-01-01

Fermilab is building a Vertical Cavity Test Facility (VCTF) to provide for R and D and pre-production testing of bare 9-cell, 1.3-GHz superconducting RF (SRF) cavities for the International Linear Collider (ILC) program. This facility is located in the existing Industrial Building 1 (IB1) where the Magnet Test Facility (MTF) also resides. Helium and nitrogen cryogenics are shared between the VCTF and MTF including the existing 1500-W at 4.5-K helium refrigerator with vacuum pumping for super-fluid operation (125-W capacity at 2-K). The VCTF is being constructed in multiple phases. The first phase is scheduled for completion in mid 2007, and includes modifications to the IB1 cryogenic infrastructure to allow helium cooling to be directed to either the VCTF or MTF as scheduling demands require. At this stage, the VCTF consists of one Vertical Test Stand (VTS) cryostat for the testing of one cavity in a 2-K helium bath. Planning is underway to provide a total of three Vertical Test Stands at VCTF, each capable of accommodating two cavities. Cryogenic infrastructure improvements necessary to support these additional VCTF test stands include a dedicated ambient temperature vacuum pump, a new helium purification skid, and the addition of helium gas storage. This paper describes the system design and initial cryogenic operation results for the first VCTF phase, and outlines future cryogenic infrastructure upgrade plans for expanding to three Vertical Test Stands

CRYOGENIC INFRASTRUCTURE FOR FERMILAB'S ILC VERTICAL CAVITY TEST FACILITY

International Nuclear Information System (INIS)

Carcagno, R.; Ginsburg, C.; Huang, Y.; Norris, B.; Ozelis, J.; Peterson, T.; Poloubotko, V.; Rabehl, R.; Sylvester, C.; Wong, M.

2008-01-01

Fermilab is building a Vertical Cavity Test Facility (VCTF) to provide for R and D and pre-production testing of bare 9-cell, 1.3-GHz superconducting RF (SRF) cavities for the International Linear Collider (ILC) program. This facility is located in the existing Industrial Building 1 (IB1) where the Magnet Test Facility (MTF) also resides. Helium and nitrogen cryogenics are shared between the VCTF and MTF including the existing 1500-W at 4.5-K helium refrigerator with vacuum pumping for super-fluid operation (125-W capacity at 2-K). The VCTF is being constructed in multiple phases. The first phase is scheduled for completion in mid 2007, and includes modifications to the IB1 cryogenic infrastructure to allow helium cooling to be directed to either the VCTF or MTF as scheduling demands require. At this stage, the VCTF consists of one Vertical Test Stand (VTS) cryostat for the testing of one cavity in a 2-K helium bath. Planning is underway to provide a total of three Vertical Test Stands at VCTF, each capable of accommodating two cavities. Cryogenic infrastructure improvements necessary to support these additional VCTF test stands include a dedicated ambient temperature vacuum pump, a new helium purification skid, and the addition of helium gas storage. This paper describes the system design and initial cryogenic operation results for the first VCTF phase, and outlines future cryogenic infrastructure upgrade plans for expanding to three Vertical Test Stands

Global voltage control for the LEP RF system

International Nuclear Information System (INIS)

Ciapala, E.; Butterworth, A.; Peschardt, E.

1993-01-01

The LEG RF system is installed as independent 16 cavity units. In addition to the eight copper cavity units originally installed 12 units with super-conducting cavities are being added for the LEP200 energy upgrade. The total RF voltage determines the synchrotron tune (Qs) and must be controlled precisely during energy ramping. Local function generators in each of the RF units are pre-loaded such that when triggered simultaneously by ramp timing events transmitted over the general timing system the total voltage varies to give the Qs function required. A disadvantage is that loss of RF in a unit at any time after the loading process cannot be corrected. As the number of RF units increases automatic control of the total RF voltage and its distribution around LEP becomes desirable. A global voltage control system, based on a central VME controller, has recently been installed. It has direct and rapid access to the RF units over the LEP time division multiplexing system. Initial tests on operation and performance at fixed energy and during energy ramping are described, as well as the implementation of a Qs loop in which Qs can be set directly using on-line synchrotron frequency measurements

Studies of RF Breakdown of Metals in Dense Gases

CERN Document Server

Hanlet, Pierrick M; Ankenbrandt, Charles; Johnson, Rolland P; Kaplan, Daniel; Kuchnir, Moyses; Moretti, Alfred; Paul, Kevin; Popovic, Milorad; Yarba, Victor; Yonehara, Katsuya

2005-01-01

A study of RF breakdown of metals in gases has begun as part of a program to develop RF cavities filled with dense hydrogen gas to be used for muon ionization cooling. A pressurized 800 MHz test cell has been used at Fermilab to compare the conditioning and breakdown behavior of copper, molybdenum, chromium, and beryllium electrodes as functions of hydrogen and helium gas density. These results are compared to the predicted or known RF breakdown behavior of these metals in vacuum.

Low-level RF control system issues for an ADTT accelerator

International Nuclear Information System (INIS)

Ziomek, C.D.; Regan, A.H.; Lynch, M.T.; Bowling, P.S.

1994-01-01

The RF control system for a charged-particle accelerator must maintain the correct amplitude and phase of RF field inside the accelerator cavity in the presence of perturbations, noises, and time varying system components. For an accelerator with heavy beam-loading, fluctuations in the beam current cause large perturbations to the RF field amplitude and phase that must be corrected by the RF control system. The ADTT applications require a high-current, heavily beam-loaded, continuous-wave (CW) accelerator. Additional concerns created by the CW operation include system start-up, beam interruption, and fault recovery. Also, the RF control system for an ADTT facility must include sophisticated automation to reduce the operator interaction and support. This paper describes an RF control system design that addresses these various issues by evaluation a combination of feedback and feed forward control techniques. Experience from the high-current Ground Test Accelerator (GTA) is drawn upon for this RF control system design. Comprehensive computer modeling with the Matrix x software has been used to predict the performance of this RF control system

Femtosecond precision measurement of laser–rf phase jitter in a photocathode rf gun

International Nuclear Information System (INIS)

Shi, Libing; Zhao, Lingrong; Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhu, Pengfei; Xiang, Dao

2017-01-01

We report on the measurement of the laser–rf phase jitter in a photocathode rf gun with femtosecond precision. In this experiment four laser pulses with equal separation are used to produce electron bunch trains; then the laser–rf phase jitter is obtained by measuring the variations of the electron bunch spacing with an rf deflector. Furthermore, we show that when the gun and the deflector are powered by the same rf source, it is possible to obtain the laser–rf phase jitter in the gun through measurement of the beam–rf phase jitter in the deflector. Based on these measurements, we propose an effective time-stamping method that may be applied in MeV ultrafast electron diffraction facilities to enhance the temporal resolution.

Femtosecond precision measurement of laser–rf phase jitter in a photocathode rf gun

Energy Technology Data Exchange (ETDEWEB)

Shi, Libing; Zhao, Lingrong; Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhu, Pengfei; Xiang, Dao, E-mail: dxiang@sjtu.edu.cn

2017-03-21

We report on the measurement of the laser–rf phase jitter in a photocathode rf gun with femtosecond precision. In this experiment four laser pulses with equal separation are used to produce electron bunch trains; then the laser–rf phase jitter is obtained by measuring the variations of the electron bunch spacing with an rf deflector. Furthermore, we show that when the gun and the deflector are powered by the same rf source, it is possible to obtain the laser–rf phase jitter in the gun through measurement of the beam–rf phase jitter in the deflector. Based on these measurements, we propose an effective time-stamping method that may be applied in MeV ultrafast electron diffraction facilities to enhance the temporal resolution.

Klystron equalization for RF feedback

International Nuclear Information System (INIS)

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 ampersand D effort here at SLAC

Rf power sources

International Nuclear Information System (INIS)

Allen, M.A.

1988-01-01

In this paper, the author reports on RF power sources for accelerator applications. The approach will be with particular customers in mind. These customers are high energy physicists who use accelerators as experimental tools in the study of the nucleus of the atom, and synchrotron light sources derived from electron or positron storage rings. The author pays close attention to electron- positron linear accelerators since the RF sources have always defined what is possible to achieve with these accelerators. Circular machines, cyclotrons, synchrotrons, etc. have usually not been limited by the RF power available and the machine builders have usually had their RF power source requirements met off the shelf. The main challenge for the RF scientist has been then in the areas of controls. An interesting example of this is in the Conceptual Design Report of the Superconducting Super Collider (SSC) where the RF system is described in six pages of text in a 700-page report. Also, the cost of that RF system is about one-third of a percent of the project's total cost. The RF system is well within the state of the art and no new power sources need to be developed. All the intellectual effort of the system designer would be devoted to the feedback systems necessary to stabilize beams during storage and acceleration, with the main engineering challenges (and costs) being in the superconducting magnet lattice

Low-level rf system for the AGS Light Ion Program

International Nuclear Information System (INIS)

Kovarik, V.; Ahrens, L.; Barton, D.S.; Frankel, R.; Otis, A.; Pope, D.; Pritsker, M.; Raka, E.; Warkentien, R.

1987-01-01

The new low level rf system for the light ion acceleration program features direct digital control of a phase continuous rf synthesizer clocked by finite changes in the B field. The system, its operation and testing are described. The system covers the complete rf frequency range and switches over from single cavity acceleration to multiple cavity acceleration with no beam loss. It also switches from the programmed drive to the normal bootstrap system

Feedback system of the RF phase in KEK-ATF linac

Energy Technology Data Exchange (ETDEWEB)

Okugi, T.; Hayano, H.; Kuriki, M.; Naito, T. [Accelerator Laboratory, High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2000-07-01

KEK-ATF linac is built in the Assembly Hall for TRISTAN project in 1991. The thermal condition of the hall is not good enough for a stable linac operation, because the temperature of the klystron gallery is drifted by 1degC within one day. RF phase is also drifted by 3-5deg of the S-band frequency in day and night. In order to control the RF phase, we installed RF phase detectors, which have S/H circuit in order to use for pulsed RF. By using the phase detector, an RF phase feedback system was tested. It was found that a stable klystron operation could be performed within the phase drift of {+-}0.5deg in a day. (author)

Operation of the APS rf gun

International Nuclear Information System (INIS)

Lewellen, J. W.

1998-01-01

The Advanced Photon Source (APS) has a thermionic-cathode rf gun system capable of providing beam to the APS linac. The gun system consists of a 1.6-cell thermionic-cathode rf gun, a fast kicker for beam current control, and an alpha magnet for bunch compression and injection into the APS linac line. This system is intended for use both as an injector for positron creation, and as a first beam source for the Low-Energy Undulator Test Line (LEUTL) project [1]. The first measured performance characteristics of the gun are presented.

rf reference line for PEP

International Nuclear Information System (INIS)

Schwarz, H.D.; Weaver, J.N.

1979-03-01

A rf phase reference line in 6 segments around the 2200 meter circumference PEP storage ring is described. Each segment of the reference line is phase stabilized by its own independent feedback system, which uses an amplitude modulated reflection from the end of each line. The modulation is kept small and decoupled from the next segment to avoid crosstalk and significant modulation of the rf drive signal. An error evaluation of the system is made. The technical implementation and prototype performance are described. Prototype tests indicate that the phase error around the ring can be held below 1 degree with this relatively simple system

rf reference line for PEP

Energy Technology Data Exchange (ETDEWEB)

Schwarz, H.D.; Weaver, J.N.

1979-03-01

A rf phase reference line in 6 segments around the 2200 meter circumference PEP storage ring is described. Each segment of the reference line is phase stabilized by its own independent feedback system, which uses an amplitude modulated reflection from the end of each line. The modulation is kept small and decoupled from the next segment to avoid crosstalk and significant modulation of the rf drive signal. An error evaluation of the system is made. The technical implementation and prototype performance are described. Prototype tests indicate that the phase error around the ring can be held below 1 degree with this relatively simple system.

RF Measurement Concepts

CERN Document Server

Caspers, F

2014-01-01

For the characterization of components, systems and signals in the radiofrequency (RF) and microwave ranges, several dedicated instruments are in use. In this article the fundamentals of the RF signal techniques are discussed. The key element in these front ends is the Schottky diode which can be used either as a RF mixer or as a single sampler. The spectrum analyser has become an absolutely indispensable tool for RF signal analysis. Here the front end is the RF mixer as the RF section of modern spectrum analyses has a ra ther complex architecture. The reasons for this complexity and certain working principles as well as limitations are discussed. In addition, an overview of the development of scalar and vector signal analysers is given. For the determination of the noise temperature of a one-port and the noise figure of a two-port, basic concepts and relations are shown as well as a brief discussion of commonly used noise-measurement techniques. In a further part of this article the operating principles of n...

Design of RF system for CYCIAE-230 superconducting cyclotron

Energy Technology Data Exchange (ETDEWEB)

Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

2017-05-11

The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push–pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

Design of RF system for CYCIAE-230 superconducting cyclotron

Science.gov (United States)

Yin, Zhiguo; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

2017-05-01

The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push-pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

Evaluation of gamma ray durability and its application of shielded RF tags

International Nuclear Information System (INIS)

Teraura, Nobuyuki; Ito, Kunio; Kobayashi, Daisuke; Sakurai, Kouichi

2015-01-01

In this study, the RF (Radio Frequency) tag with radiation shield is developed and its gamma ray durability is evaluated. RFID (RF Identification) is a radio-wave-based identification technology that can be used for various items. RF tags find use in many applications, including item tracing, access control, etc. RF tags can be classified as active RF tags, which have inbuilt voltaic cells, and passive RF tags without these cells. Passive RF tags, known for their low price and durability, are used in various fields. For instance, they are used for equipment maintenance in factories and thermal power plants. Several frequencies are used for RF tags. Further, RF tagging on the UHF (Ultra High Frequency) frequencies allows a communication range of approximately 10 m, and thus, remote reading is possible. When used in radiation environments such as in nuclear power plants, remote reading can contribute to the reduction of radiation exposure. However, because semiconductors are the primary elements used in the manufacture of RF tags, they can be damaged by radiation, and operational errors can occur. Therefore, this technology has not been used in environments affected by relatively high radiation levels. Therefore, in nuclear power plants, the use of RF tags is limited in areas of low radiation levels. In our study, we develop and manufacture a new RF tag with a radiation shield cover that provides error correction functionality. It is expected that radiation shielded RF tags will improve the radiation-proof feature, and its application range will be expanded. Using the radiation-proof RF tag, we have conducted radiation durability tests. These tests are of two types: one using low energy gamma ray, and the other using high-energy gamma ray. Experimental results are then analyzed. The number of applications for radiation shielded RF tags is considerably increasing, because it can be used in various radiation environments other than nuclear power plants as well, such as

Microscopic investigation of RF surfaces of 3 GHz niobium accelerator cavities following RF processing

International Nuclear Information System (INIS)

Graber, J.; Barnes, P.; Flynn, T.; Kirchgessner, J.; Knobloch, J.; Moffat, D.; Muller, H.; Padamsee, H.; Sears, J.

1993-01-01

RF processing of Superconducting accelerating cavities is achieved through a change in the electron field emission (FE) characteristics of the RF surface. The authors have examined the RF surfaces of several single-cell 3 GHz cavities, following RF processing, in a Scanning Electron Microscope (SEM). The RF processing sessions included both High Peak Power (P ≤ 50 kW) pulsed processing, and low power (≤ 20 W) continuous wave processing. The experimental apparatus also included a thermometer array on the cavity outer wall, allowing temperature maps to characterize the emission before and after RF processing gains. Multiple sites have been located in cavities which showed improvements in cavity behavior due to RF processing. Several SEM-located sites can be correlated with changes in thermometer signals, indicating a direct relationship between the surface site and emission reduction due to RF processing. Information gained from the SEM investigations and thermometry are used to enhance the theoretical model of RF processing

Falls classification using tri-axial accelerometers during the five-times-sit-to-stand test.

Science.gov (United States)

Doheny, Emer P; Walsh, Cathal; Foran, Timothy; Greene, Barry R; Fan, Chie Wei; Cunningham, Clodagh; Kenny, Rose Anne

2013-09-01

The five-times-sit-to-stand test (FTSS) is an established assessment of lower limb strength, balance dysfunction and falls risk. Clinically, the time taken to complete the task is recorded with longer times indicating increased falls risk. Quantifying the movement using tri-axial accelerometers may provide a more objective and potentially more accurate falls risk estimate. 39 older adults, 19 with a history of falls, performed four repetitions of the FTSS in their homes. A tri-axial accelerometer was attached to the lateral thigh and used to identify each sit-stand-sit phase and sit-stand and stand-sit transitions. A second tri-axial accelerometer, attached to the sternum, captured torso acceleration. The mean and variation of the root-mean-squared amplitude, jerk and spectral edge frequency of the acceleration during each section of the assessment were examined. The test-retest reliability of each feature was examined using intra-class correlation analysis, ICC(2,k). A model was developed to classify participants according to falls status. Only features with ICC>0.7 were considered during feature selection. Sequential forward feature selection within leave-one-out cross-validation resulted in a model including four reliable accelerometer-derived features, providing 74.4% classification accuracy, 80.0% specificity and 68.7% sensitivity. An alternative model using FTSS time alone resulted in significantly reduced classification performance. Results suggest that the described methodology could provide a robust and accurate falls risk assessment. Copyright © 2013 Elsevier B.V. All rights reserved.

Vortex formation during rf heating of plasma

International Nuclear Information System (INIS)

Motley, R.W.

1980-05-01

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

INTRODUCING NOVEL GENERATION OF HIGH ACCURACY CAMERA OPTICAL-TESTING AND CALIBRATION TEST-STANDS FEASIBLE FOR SERIES PRODUCTION OF CAMERAS

Directory of Open Access Journals (Sweden)

M. Nekouei Shahraki

2015-12-01

Full Text Available The recent advances in the field of computer-vision have opened the doors of many opportunities for taking advantage of these techniques and technologies in many fields and applications. Having a high demand for these systems in today and future vehicles implies a high production volume of video cameras. The above criterions imply that it is critical to design test systems which deliver fast and accurate calibration and optical-testing capabilities. In this paper we introduce new generation of test-stands delivering high calibration quality in single-shot calibration of fisheye surround-view cameras. This incorporates important geometric features from bundle-block calibration, delivers very high (sub-pixel calibration accuracy, makes possible a very fast calibration procedure (few seconds, and realizes autonomous calibration via machines. We have used the geometrical shape of a Spherical Helix (Type: 3D Spherical Spiral with special geometrical characteristics, having a uniform radius which corresponds to the uniform motion. This geometrical feature was mechanically realized using three dimensional truncated icosahedrons which practically allow the implementation of a spherical helix on multiple surfaces. Furthermore the test-stand enables us to perform many other important optical tests such as stray-light testing, enabling us to evaluate the certain qualities of the camera optical module.

RF capacitance-voltage characterization of MOSFETs with high-leakage dielectric

NARCIS (Netherlands)

Schmitz, Jurriaan; Cubaynes, F.N; Cubaynes, F.N.; Havens, R.J.; de Kort, R.; Scholten, A.J.; Tiemeijer, L.F.

2003-01-01

We present a MOS Capacitance-Voltage measurement methodology that, contrary to present methods, is highly robust against gate leakage current densities up to 1000 A/cm/sup 2/. The methodology features specially designed RF test structures and RF measurement frequencies. It allows MOS parameter

Experimental investigation of heating phenomena in linac mechanical interfaces due to RF field penetration

International Nuclear Information System (INIS)

Fazio, M.V.; Reid, D.W.; Potter, J.M.

1981-01-01

In a high duty-factor, high-current, drift-tube linear accelerator, a critical interface exists between the drift-tube stem and the tank wall. This interface must provide vacuum integrity and RF continuity, while simultaneously allowing alignment flexibility. Because of past difficulties with RF heating of vacuum bellows and RF joints encountered by others, a paucity of available information, and the high reliability requirement for the Fusion Materials Irradiation Test (FMIT) accelerator, a program was initiated to study the problem. Because RF heating is the common failure mode, an attempt was made to find a correlation between the drift-tube-stem/linac-tank interface geometry and RF field penetration from the tank into the interface region. Experiments were performed at 80 MHz on an RF structure designed to simulate the conditions to which a drift-tube stem and vacuum bellows are exposed in a drift-tube linac. Additional testing was performed on a 367-MHz model of the FMIT prototype drift-tube linac. Experimental results, and a method to predict excessive RF heating, is presented. An experimentally tested solution to the problem is discussed

Accelerating Rf Station For Hirfl-csr, Lanzhou, China

CERN Document Server

Arbuzov, V S; Dranichnikov, A N; Gorniker, E I; Kondakov, A A; Kondaurov, M; Kruchkov, Ya G; Krutikhin, S A; Kurkin, G Ya; Mironenko, L A; Motygin, S V; Osipov, V N; Petrov, V M; Pilan, Andrey M; Popov, A M; Sedlyarov, I K; Selivanov, A N; Shteinke, A R; Vajenin, N F

2004-01-01

In accordance with the plan of cooperation with the Institute of Modern Physics (IMP), Lanzhou, China, the Budker Institute of Nuclear Physics (BINP), Novosibirsk, Russia has produced and supplied an accelerating RF station for the multipurpose Cooling Storage Ring system (CSR), which is being constructed at IMP. The RF station had been tested at IMP site and now is installed into the Main Ring of the facilities. The RF station operates in the frequency range of 0.25~1.7 MHz. Maximum accelerating voltage is 8 kV. The resonance frequency of the RF cavity is tuned in the whole frequency range by biasing of ferrites, which are used in the cavity. Ferrites of 600NN type were produced by a firm manufacture "Magneton", St. Petersburg. The pressure in the cavity vacuum chamber is lower, than 3·10-11

Low power RF beam control electronics for the LEB

International Nuclear Information System (INIS)

Mestha, L.K.; Mangino, J.; Brouk, V.; Uher, T.; Webber, R.C.

1993-05-01

Beam Control Electronics for the Low Energy Booster (LEB) should provide a fine reference phase and frequency for the High Power RF System. Corrections applied on the frequency of the rf signal will reduce dipole synchrotron oscillations due to power supply regulation errors, errors in frequency source or errors in the cavity voltage. It will allow programmed beam radial position control throughout the LEB acceleration cycle. Furthermore the rf signal provides necessary connections during, adiabatic capture of the beam as injected into the LEB by the Linac and will guarantee LEB rf phase synchronism with the Medium Energy Booster (MEB) rf at a programmed time in the LEB cycle between a unique LEB bucket and a unique MEB bucket. We show in this paper a design and possible interfaces with other subsystems of the LEB such as the beam instrumentation, High Power RF Stations, global accelerator controls and the precision timing system. The outline of various components of the beam control system is also presented followed by some test results

Design and implementation of a crystal collimation test stand at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Mirarchi, D.; Redaelli, S.; Scandale, W. [CERN, European Organization for Nuclear Research, Geneva 23 (Switzerland); Hall, G. [Imperial College, Blackett Laboratory, London (United Kingdom)

2017-06-15

Future upgrades of the CERN Large Hadron Collider (LHC) demand improved cleaning performance of its collimation system. Very efficient collimation is required during regular operations at high intensities, because even a small amount of energy deposited on superconducting magnets can cause an abrupt loss of superconducting conditions (quench). The possibility to use a crystal-based collimation system represents an option for improving both cleaning performance and impedance compared to the present system. Before relying on crystal collimation for the LHC, a demonstration under LHC conditions (energy, beam parameters, etc.) and a comparison against the present system is considered mandatory. Thus, a prototype crystal collimation system has been designed and installed in the LHC during the Long Shutdown 1 (LS1), to perform feasibility tests during the Run 2 at energies up to 6.5 TeV. The layout is suitable for operation with proton as well as heavy ion beams. In this paper, the design constraints and the solutions proposed for this test stand for feasibility demonstration of crystal collimation at the LHC are presented. The expected cleaning performance achievable with this test stand, as assessed in simulations, is presented and compared to that of the present LHC collimation system. The first experimental observation of crystal channeling in the LHC at the record beam energy of 6.5 TeV has been obtained in 2015 using the layout presented (Scandale et al., Phys Lett B 758:129, 2016). First tests to measure the cleaning performance of this test stand have been carried out in 2016 and the detailed data analysis is still on-going. (orig.)

Design and implementation of a crystal collimation test stand at the Large Hadron Collider

International Nuclear Information System (INIS)

Mirarchi, D.; Redaelli, S.; Scandale, W.; Hall, G.

2017-01-01

Future upgrades of the CERN Large Hadron Collider (LHC) demand improved cleaning performance of its collimation system. Very efficient collimation is required during regular operations at high intensities, because even a small amount of energy deposited on superconducting magnets can cause an abrupt loss of superconducting conditions (quench). The possibility to use a crystal-based collimation system represents an option for improving both cleaning performance and impedance compared to the present system. Before relying on crystal collimation for the LHC, a demonstration under LHC conditions (energy, beam parameters, etc.) and a comparison against the present system is considered mandatory. Thus, a prototype crystal collimation system has been designed and installed in the LHC during the Long Shutdown 1 (LS1), to perform feasibility tests during the Run 2 at energies up to 6.5 TeV. The layout is suitable for operation with proton as well as heavy ion beams. In this paper, the design constraints and the solutions proposed for this test stand for feasibility demonstration of crystal collimation at the LHC are presented. The expected cleaning performance achievable with this test stand, as assessed in simulations, is presented and compared to that of the present LHC collimation system. The first experimental observation of crystal channeling in the LHC at the record beam energy of 6.5 TeV has been obtained in 2015 using the layout presented (Scandale et al., Phys Lett B 758:129, 2016). First tests to measure the cleaning performance of this test stand have been carried out in 2016 and the detailed data analysis is still on-going. (orig.)

Design and implementation of a crystal collimation test stand at the Large Hadron Collider

Science.gov (United States)

Mirarchi, D.; Hall, G.; Redaelli, S.; Scandale, W.

2017-06-01

Future upgrades of the CERN Large Hadron Collider (LHC) demand improved cleaning performance of its collimation system. Very efficient collimation is required during regular operations at high intensities, because even a small amount of energy deposited on superconducting magnets can cause an abrupt loss of superconducting conditions (quench). The possibility to use a crystal-based collimation system represents an option for improving both cleaning performance and impedance compared to the present system. Before relying on crystal collimation for the LHC, a demonstration under LHC conditions (energy, beam parameters, etc.) and a comparison against the present system is considered mandatory. Thus, a prototype crystal collimation system has been designed and installed in the LHC during the Long Shutdown 1 (LS1), to perform feasibility tests during the Run 2 at energies up to 6.5 TeV. The layout is suitable for operation with proton as well as heavy ion beams. In this paper, the design constraints and the solutions proposed for this test stand for feasibility demonstration of crystal collimation at the LHC are presented. The expected cleaning performance achievable with this test stand, as assessed in simulations, is presented and compared to that of the present LHC collimation system. The first experimental observation of crystal channeling in the LHC at the record beam energy of 6.5 TeV has been obtained in 2015 using the layout presented (Scandale et al., Phys Lett B 758:129, 2016). First tests to measure the cleaning performance of this test stand have been carried out in 2016 and the detailed data analysis is still on-going.

1 ms pulse beam generation and acceleration by photo-cathode RF gun

International Nuclear Information System (INIS)

Watanabe, Ken; Hayano, Hitoshi; Urakawa, Jyunji

2012-01-01

We report successful generation of 1 ms long pulse and multi-bunch electron beam by a normal conducting photo-cathode RF gun at KEK-STF (Superconducting accelerator Test Facility). The 1 ms long Pulse beam generated by the RF gun is delivered to the injection line to examine stable acceleration and precise RF control. The 1 ms pulse beam is also used to demonstrate high brightness X-ray generation by inverse laser Compton scattering which will be also carried out at STF, supported by MEXT Quantum Beam project. The RF gun cavity has been fabricated by DESY-FNAL-KEK collaboration. Performing high power RF process and ethanol rinse to the cavity, a stable operation of the cavity up to 4.0 MW RF input power with ∼1 ms pulse length was achieved by keeping even low dark current. The beam generation test has been started since February 2012, 1 ms pulse was generated in March 2012. We explain about the STF injector and report the basic property of this 1 ms beam generation. (author)

Performance review of thermionic electron gun developed for RF linear accelerators at RRCAT

International Nuclear Information System (INIS)

Wanmode, Yashwant; Mulchandani, J.; Reddy, T.S.; Bhisikar, A.; Singh, H.G.; Shrivastava, Purushottam

2015-01-01

RRCAT is engaged in development of RF electron linear accelerator for irradiation of industrial and agricultural products. Thermionic electron gun is primary source for this accelerator as beam current in the RF accelerator is modest and thermionic emission is most prevalent option for electron gun development. An electron gun has to meet high cathode emission capability, low filament power, good accessibility for cathode replacement and should provide short time for maintenance. Electron linear accelerator up to beam energy of 10 MeV require electron source of 45-50 keV beam energy and emission current of 1 A. Electron optics of gun and electron beam profile simulations were carried out using CST's particle tracking code and EGUN code. Triode type electron gun of cathode voltage 50 kV pulsed has been designed, developed and integrated with 10 MeV electron linear accelerators at RRCAT. Beam current of more than 600 mA has been measured with faraday cup in the test stand developed for characterizing the electron gun. Two accelerators one is imported and another one developed indigenously has been energized using this electron gun. Beam energy of 5-10 MeV has been achieved with beam current of 250-400 mA by integrating this electron gun with the linear accelerator. This paper reviews the performance of indigenously developed electron gun for both linear accelerators. (author)

The stripping foil test stand in the Linac4 transfer line

CERN Document Server

Weterings, W; Noulibos, R; Sillanoli, Y; van Trappen, P

2015-01-01

The 160 MeV H− beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H− charge-exchange injection system. It will include a stripping foil, to convert H− into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters.

The stripping foil test stand in the Linac4 transfer line

International Nuclear Information System (INIS)

Weterings, W.; Bracco, C.; Noulibos, R.; Sillanoli, Y.; Trappen van, P.

2015-01-01

The 160 MeV H - beam from the Linac4 (L4) linear accelerator at CERN will be injected into the proton synchrotron booster (PSB) with a new H - charge-exchange injection system. It will include a stripping foil, to convert H - into protons by stripping off the electrons. To gain experience with these very fragile foils, prior to the installation in the PSB, and test different foil materials and thicknesses, lifetimes of the foils, the foil changing mechanism and interlocking functions, a stripping foil test stand will be installed in the L4 transfer line in 2015. This paper describes the mechanical design of the system and discusses the test possibilities and parameters. (author)

Electronics system for the 150 kV negative ion test stand at BNL

International Nuclear Information System (INIS)

Larson, R.A.

1977-01-01

The 150 kV test stand at BNL is being used to investigate the extraction, acceleration and transport problems associated with the development of intense negative ion beams. The power supplies associated with these functions as well as the control and monitoring electronics are described

High Peak Power Test and Evaluation of S-band Waveguide Switches

Science.gov (United States)

Nassiri, A.; Grelick, A.; Kustom, R. L.; White, M.

1997-05-01

The injector and source of particles for the Advanced Photon Source is a 2856-MHz S-band electron-positron linear accelerator (linac) which produces electrons with energies up to 650 MeV or positrons with energies up to 450 MeV. To improve the linac rf system availability, an additional modulator-klystron subsystem is being constructed to provide a switchable hot spare unit for each of the five exsisting S-band transmitters. The switching of the transmitters will require the use of SF6-pressurized S-band waveguide switches at a peak operating power of 35 MW. Such rf switches have been successfully operated at other accelerator facilities but at lower peak powers. A test stand has been set up at the Stanford Linear Accelerator Center (SLAC) Klystron Factory to conduct tests comparing the power handling characteristics of two WR-284 and one WR-340 switches. Test results are presented and their implications for the design of the switching system are discussed.

Optimization of a readout board for mass assembly and light yield measurements with a cosmic ray test stand

Energy Technology Data Exchange (ETDEWEB)

Chau, Phi [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany); Collaboration: CALICE-D-Collaboration

2016-07-01

We have built a readout board prototype, equipped with SiPMs, scintillators and readout electronics for an highly granular calorimeter. The design was optimized for mass assembly due to about 8 million channels in the final detector. The prototype showed good performance in several test beams and in a cosmic ray test stand, which was built to characterize the MIP response of these kinds of boards. We show an overview of the cosmic ray test stand and measurement results for the readout board and plans for an improved 2nd generation prototype.

Rf System for the NLCTA

International Nuclear Information System (INIS)

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

2011-01-01

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

Cryogenic infrastructure for Fermilab's ILC vertical cavity test facility

Energy Technology Data Exchange (ETDEWEB)

Carcagno, R.; Ginsburg, C.; Huang, Y.; Norris, B.; Ozelis, J.; Peterson, T.; Poloubotko, V.; Rabehl, R.; Sylvester, C.; Wong, M.; /Fermilab

2006-06-01

Fermilab is building a Vertical Cavity Test Facility (VCTF) to provide for R&D and pre-production testing of bare 9-cell, 1.3-GHz superconducting RF (SRF) cavities for the International Linear Collider (ILC) program. This facility is located in the existing Industrial Building 1 (IB1) where the Magnet Test Facility (MTF) also resides. Helium and nitrogen cryogenics are shared between the VCTF and MTF including the existing 1500-W at 4.5-K helium refrigerator with vacuum pumping for super-fluid operation (125-W capacity at 2-K). The VCTF is being constructed in multiple phases. The first phase is scheduled for completion in mid 2007, and includes modifications to the IB1 cryogenic infrastructure to allow helium cooling to be directed to either the VCTF or MTF as scheduling demands require. At this stage, the VCTF consists of one Vertical Test Stand (VTS) cryostat for the testing of one cavity in a 2-K helium bath. Planning is underway to provide a total of three Vertical Test Stands at VCTF, each capable of accommodating two cavities. Cryogenic infrastructure improvements necessary to support these additional VCTF test stands include a dedicated ambient temperature vacuum pump, a new helium purification skid, and the addition of helium gas storage. This paper describes the system design and initial cryogenic operation results for the first VCTF phase, and outlines future cryogenic infrastructure upgrade plans for expanding to three Vertical Test Stands.

Development of a Solid State RF Amplifier in the kW Regime for Application with Low Beta Superconducting RF Cavities

CERN Document Server

Piel, Christian; Borisov, A; Kolesov, Sergej; Piel, Helmut

2005-01-01

Projects based on the use of low beta superconducting cavities for ions are under operation or development at several labs worldwide. Often these cavities are individually driven by RF power sources in the kW regime. For an ongoing project a modular 2 kW, 176 MHz unconditionally stable RF amplifier for CW and pulsed operation was designed, built, and tested. Extended thermal analysis was used to develop a water cooling system in order to optimize the performance of the power transistors and other thermally loaded components. The paper will outline the design concept of the amplifier and present first results on the test of the amplifier with a superconducting cavity.

Microsatellite-Aided Screening for Fertility Restoration Genes (Rf Facilitates Hybrid Improvement

Directory of Open Access Journals (Sweden)

Raafat El-Namaky

2016-05-01

Full Text Available DNA markers enabled to determine the chromosomal locations of the two Rf genes (Rf3 and Rf4 in the wild-abortive cytoplasmic male sterility (WA-CMS system. Four simple sequence repeats (SSRs RM171, RM258, RM315 and RM443 were used to detect the allelic status with respect to the fertility restoration genes (Rf3 and Rf4 in 300 rice cultivars or breeding lines. The results revealed that out of 300 lines, 90 lines screened had Rf3, 65 lines had Rf4, and 45 lines had Rf3 and Rf4 alleles. Furthermore, 45 lines selected using SSR markers were mated with a CMS line (IR58025A to analyze their restoring ability. Offspring of all the test lines except HHZ8-SAL9DT1-Y1, HHZ5-SAL9-Y3-1 and IDSA77 exhibited higher pollen and spikelet fertility (> 80%, thus confirming they bear the Rf alleles. The hybrid offspring of ARH12-6-1-1-B-3-1, IR32307-10-3-2-1 and Sahel 329 had the highest pollen fertility (97.39%, 98.30% and 97.10%, respectively and spikelet fertility (95.10%, 97.07% and 96.10%, respectively.

RF Coupler Design for the TRIUMF ISAC-II Superconducting Quarter Wave Resonator

CERN Document Server

Poirier, R L; Harmer, P; Laxdal, R E; Mitra, A K; Sekatchev, I; Waraich, B; Zvyagintsev, V

2004-01-01

An RF Coupler for the ISAC-II medium beta (β=0.058 and 0.071) superconducting quarter wave resonators was designed and tested at TRIUMF. The main goal of this development was to achieve stable operation of superconducting cavities at high acceleration gradients and low thermal load to the helium refrigeration system. The cavities will operate at 6 MV/m acceleration gradient in overcoupled mode at a forward power 200 W at 106 MHz. The overcoupling provides ±20 Hz cavity bandwidth, which improves the stability of the RF control system for fast helium pressure fluctuations, microphonics and environmental noise. Choice of materials, cooling with liquid nitrogen, aluminum nitride RF window and thermal shields insure a small thermal load on the helium refrigeration system by the Coupler. An RF finger contact which causedμdust in the coupler housing was eliminated without any degradation of the coupler performance. RF and thermal calculations, design and test results on the coupler are p...

Status of RF beryllium characterization for ITER Fist Wall

Science.gov (United States)

Kupriyanov, I. B.; Nikolaev, G. N.; Roedig, M.; Gervash, A. А.; Linke, I. J.; Kurbatova, L. A.; Perevalov, S. I.; Giniyatulin, R. N.

2011-10-01

The status of RF R&D activities in production and characterization of TGP-56FW beryllium grade is presented. The results of metallographic studies of microstructure and cracks morphology are reported for full-scale Be tiles (56 × 56 × 10 mm) subjected to VDE simulation tests in TSEFEY-M testing facility (VDE-10 MJ/m 2 during 0.1 s, 1 shot ) and following low cycle thermal fatigue tests (500 thermal cycles at 1.5 MW/m 2). First results of plasma disruption tests ( E = 1.2-5 MJ/m 2, 5 ms), which were obtained during the realization of Thermal Shock/VDE Qualification program of RF beryllium in JUDITH-1 facility, are also discussed.

Status of RF beryllium characterization for ITER Fist Wall

International Nuclear Information System (INIS)

Kupriyanov, I.B.; Nikolaev, G.N.; Roedig, M.; Gervash, A.A.; Linke, I.J.; Kurbatova, L.A.; Perevalov, S.I.; Giniyatulin, R.N.

2011-01-01

The status of RF R and D activities in production and characterization of TGP-56FW beryllium grade is presented. The results of metallographic studies of microstructure and cracks morphology are reported for full-scale Be tiles (56 x 56 x 10 mm) subjected to VDE simulation tests in TSEFEY-M testing facility (VDE-10 MJ/m 2 during 0.1 s, 1 shot) and following low cycle thermal fatigue tests (500 thermal cycles at 1.5 MW/m 2 ). First results of plasma disruption tests (E = 1.2-5 MJ/m 2 , 5 ms), which were obtained during the realization of Thermal Shock/VDE Qualification program of RF beryllium in JUDITH-1 facility, are also discussed.

Design and RF Test of Broadband Coaxial Hybrid Splitter for ITER ICRF System

Energy Technology Data Exchange (ETDEWEB)

Kim, H. J.; Wang, S. J.; Park, B. H.; Yang, H. L.; Kwak, J. G. [National Fusion Research Institute, Daejeon (Korea, Republic of); Choi, J. J. [Kwangwoon Univ., Seoul (Korea, Republic of)

2013-10-15

The ICRF system of the ITER is required to couple 20 MW to the plasma in the 40∼55 MHz frequency band for RF heating and current drive operation. The corresponding matching system of ICRF antenna must be load-resilient for a wide range of antenna load variations due to mode transitions or edge localized modes. Indeed the use of hybrid splitters ensures that no reflections occur at the generator when the reflections on the adjacent lines are equal both in magnitude and in phase, in which case all reflected power will not be seen by the generators and will be returned to the dummy loads. Most 3 dB coaxial hybrid circuits installed and implemented on the ICRF system is single section coupler providing best performance at the design frequency with narrow bandwidth. The bandwidth of such a single-section 3 dB hybrid coupler is limited to less than 20% due to the quarter wavelength transmission line requirement. The amplitude balance becomes rapidly degraded away from the center frequency. We designed, fabricated and tested a high power, ultra-wideband two-section 3 dB coaxial hybrid coupler over all frequencies from 40 MHz to 55 MHz for ITER ICRF system by configuring asymmetric impedance matching. We have designed, fabricated, and tested a 3-dB wideband hybrid coupler for stable and load resilient operation of the ITER ICRF system. The wideband two section 3-dB coaxial hybrid coupler was well designed by configuring asymmetric impedance matching using HFSS. In the rf measurements, we found that wideband hybrid splitter has an amplitude imbalance of 0.1 dB over all frequencies from 40 MHz to 55 MHz. We expect that wideband hybrid splitter will be applicable to ITER ICRF matching system for load resilient operation at fusion plasmas.

Design and commissioning of Fermilab's vertical test stand for ILC SRF cavities

International Nuclear Information System (INIS)

Ozelis, Joseph P.; Carcagno, Ruben; Ginsburg, Camille M.; Huang, Yuenian; Norris, Barry; Peterson, Thomas; Poloubotko, Valeri; Rabehl, roger; Rakhno, Igor; Reid, Clark; Sergatskov, Dmitri A.

2007-01-01

As part of its ILC program, Fermilab is developing a facility for vertical testing of SRF cavities. It operates at a nominal temperature of 2K, using a cryoplant that can supply LHe in excess of 20g/sec and provide bath pumping capacity of 125W at 2K. The below-grade cryostat consists of a vacuum vessel and LHe vessel, equipped with magnetic shielding to reduce the ambient magnetic field to <10mG. Internal fixed and external movable radiation shielding ensures that exposure to personnel is minimized. The facility features an integrated personnel safety system consisting of RF switches, interlocks, and area radiation monitors

Simulations of the BNL/SLAC/UCLA 1.6 cell emittance compensated photocathode RF gun low energy beam line

International Nuclear Information System (INIS)

Palmer, D.T.; Miller, R.H.; Winick, H.

1995-01-01

A dedicated low energy (2 to 10 MeV) experimental beam line is now under construction at Brookhaven National Laboratories Accelerator Test Facility (BNL/ATF) for photocathode RF gun testing and photoemission experiments. The design of the experimental line, using the 1.6 cell photocathode RF gun developed by the BNL/SLAC/UCLA RF gun collaboration is presented. Detailed beam dynamics simulations were performed for the 1.6 cell RF gun injector using a solenoidal emittance compensation technique. An experimental program for testing the 1.6 cell RF gun is presented. This program includes beam loading caused by dark current, higher order mode field measurements, integrated and slice emittance measurements using a pepper-pot and RF kicker cavity

Progress on a cryogenically cooled RF gun polarized electron source

Energy Technology Data Exchange (ETDEWEB)

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.

The RF Design of an HOM Polarized RF Gun for the ILC

International Nuclear Information System (INIS)

Wang, J.W.; Clendenin, J.E.; Colby, E.R.; Miller, R.A.; Lewellen, J.W.

2006-01-01

The ILC requires a polarized electron beam. While a highly polarized beam can be produced by a GaAs-type cathode in a DC gun of the type currently in use at SLAC, JLAB and elsewhere, the ILC injector system can be simplified and made more efficient if a GaAs-type cathode can be combined with a low emittance RF gun. Since this type of cathode is known to be extremely sensitive to vacuum contamination including back bombardment by electrons and ions, any successful polarized RF gun must have a significantly improved operating vacuum compared to existing RF guns. We present a new RF design for an L-Band normal conducting (NC) RF gun for the ILC polarized electron source. This design incorporates a higher order mode (HOM) structure, whose chief virtue in this application is an improved conductance for vacuum pumping on the cathode. Computer simulation models have been used to optimize the RF parameters with two principal goals: first to minimize the required RF power; second to reduce the peak surface field relative to the field at the cathode in order to suppress field emitted electron bombardment. The beam properties have been simulated initially using PARMELA. Vacuum and other practical issues for implementing this design are discussed

Accurate modeling of complete functional RF blocks: CHAMELEON RF

NARCIS (Netherlands)

Janssen, H.H.J.M.; Niehof, J.; Schilders, W.H.A.; Ciuprina, G.; Ioan, D.

2007-01-01

Next-generation nano-scale RF-IC designs have an unprecedented complexity and performance that will inevitably lead to costly re-spins and loss of market opportunities. In order to cope with this, the aim of the European Framework 6 CHAMELEON RF project is to develop methodologies and prototype

A NEW THERMIONIC RF ELECTRON GUN FOR SYNCHROTRON LIGHT SOURCES

Energy Technology Data Exchange (ETDEWEB)

Kutsaev, Sergey; Agustsson, R.; Hartzell, J; Murokh, A.; Nassiri, A.; Savin, E.; Smirnov, A.V.; Smirnov, A. Yu; Sun, Y.; Verma, A; Waldschmidt, Geoff; Zholents, A.

2017-06-02

A thermionic RF gun is a compact and efficient source of electrons used in many practical applications. RadiaBeam Systems and the Advanced Photon Source at Argonne National Laboratory collaborate in developing of a reliable and robust thermionic RF gun for synchrotron light sources which would offer substantial improvements over existing thermionic RF guns and allow stable operation with up to 1A of beam peak current at a 100 Hz pulse repetition rate and a 1.5 μs RF pulse length. In this paper, we discuss the electromagnetic and engineering design of the cavity and report the progress towards high power tests of the cathode assembly of the new gun.

Compact rf polarizer and its application to pulse compression systems

Directory of Open Access Journals (Sweden)

Matthew Franzi

2016-06-01

Full Text Available We present a novel method of reducing the footprint and increasing the efficiency of the modern multi-MW rf pulse compressor. This system utilizes a high power rf polarizer to couple two circular waveguide modes in quadrature to a single resonant cavity in order to replicate the response of a traditional two cavity configuration using a 4-port hybrid. The 11.424 GHz, high-Q, spherical cavity has a 5.875 cm radius and is fed by the circularly polarized signal to simultaneously excite the degenerate TE_{114} modes. The overcoupled spherical cavity has a Q_{0} of 9.4×10^{4} and coupling factor (β of 7.69 thus providing a loaded quality factor Q_{L} of 1.06×10^{4} with a fill time of 150 ns. Cold tests of the polarizer demonstrated good agreement with the numerical design, showing transmission of -0.05  dB and reflection back to the input rectangular WR 90 waveguide less than -40  dB over a 100 MHz bandwidth. This novel rf pulse compressor was tested at SLAC using XL-4 Klystron that provided rf power up to 32 MW and generated peak output power of 205 MW and an average of 135 MW over the discharged signal. A general network analysis of the polarizer is discussed as well as the design and high power test of the rf pulse compressor.

RF MEMS

Indian Academy of Sciences (India)

At the bare die level the insertion loss, return loss and the isolation ... ing and packaging of a silicon on glass based RF MEMS switch fabricated using DRIE. ..... follows the power law based on the asperity deformation model given by Pattona & ... Surface mount style RF packages (SMX series 580465) from Startedge Corp.

Use of a unipedal standing test to assess the ambulation reacquisition time during the early postoperative stage after hip fracture in elderly Japanese: prospective study.

Science.gov (United States)

Murata, Koichi; Sugitani, Shigeki; Yoshioka, Hiroki; Noguchi, Takashi; Aoto, Toshiyuki; Nakamura, Takashi

2010-01-01

The aim of this study was to predict the ambulation reacquisition time after hip fracture in elderly people using the unipedal standing test during the early postoperative stage. Patients with an intertrochanteric fracture treated with internal fixation (n = 35) and patients with a femoral neck fracture treated with hemiarthroplasty (n = 22) were included. A unipedal standing test using the nonoperated leg was performed on days 3 and 7 after the operation. Among the patients with an intertrochanteric fracture, those with a positive result on the unipedal standing test on postoperative day (POD) 3 attained gait with parallel guide bars (BG) and walker-assisted gait (WG) significantly earlier than did patients with a negative result on the unipedal standing test. Patients with a positive result on the unipedal standing test on POD 7 attained BG, WG, and cane-assisted gait (CG) significantly earlier than did patients with a negative test. Among patients with a femoral neck fracture, those with a positive unipedal standing test result on POD 3 attained BG, WG, and CG significantly earlier than did patients with a negative test. Those with a positive test result on POD 7 attained BG, WG, and CG significantly earlier than did patients with a negative test. The unipedal standing test given during the early postoperative stage is a good test for predicting the ambulation reacquisition time. Moreover, it gives information that can help determine the need for subacute rehabilitation and about discharge planning and health service provision.

Racetrack microtron rf system

International Nuclear Information System (INIS)

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

Investigation and Prediction of RF Window Performance in APT Accelerators

International Nuclear Information System (INIS)

Humphries, S. Jr.

1997-01-01

The work described in this report was performed between November 1996 and May 1997 in support of the APT (Accelerator Production of Tritium) Program at Los Alamos National Laboratory. The goal was to write and to test computer programs for charged particle orbits in RF fields. The well-documented programs were written in portable form and compiled for standard personal computers for easy distribution to LANL researchers. They will be used in several APT applications including the following. Minimization of multipactor effects in the moderate β superconducting linac cavities under design for the APT accelerator. Investigation of suppression techniques for electron multipactoring in high-power RF feedthroughs. Modeling of the response of electron detectors for the protection of high power RF vacuum windows. In the contract period two new codes, Trak-RF and WaveSim, were completed and several critical benchmark etests were carried out. Trak-RF numerically tracks charged particle orbits in combined electrostatic, magnetostatic and electromagnetic fields. WaveSim determines frequency-domain RF field solutions and provides a key input to Trak-RF. The two-dimensional programs handle planar or cylindrical geometries. They have several unique characteristics

How well does the 30-second Chair Stand Test predict rehabilitation needs?

DEFF Research Database (Denmark)

Hansen Bruun, Inge; Nørgaard, Birgitte; Backer Mogensen, Christian

of functional decline. The 30-Second Chair Stand Test (30s-CST) is recommended by the Danish Health and Medicines Authority for screening of functional decline in elderly citizens living in their own home. However, its validity with hospitalized patients is undocumented, and it is unclear whether loss...... performance, e) patient-related data. Both patients and health professionals will contribute to the face validity assessment. Results The results will be available by the end of 2014. Conclusions Face validations of 30s-CST and DEMMI are relevant as validated tests for short-term hospitalized patients...

Development of a novel rf waveguide vacuum valve

CERN Document Server

Grudiev, A

2006-01-01

The development of a novel rf waveguide vacuum valve is presented. The rf design is based on the use of TE0n modes of circular waveguides. In the device, the TE01 mode at the input is converted into a mixture of several TE0n modes which provide low-loss rf power transmission across the vacuum valve gap, these modes are then converted back into the TE01 mode at the output. There are a number of advantages associated with the absence of surface fields in the region of the valve: • Possibility to use commercially available vacuum valves equipped with two specially designed mode converter sections. • No necessity for an rf contact between these two sections. • Increased potential for high power rf transmission. This technology can be used for all frequencies for which vacuum waveguides are used. In rectangular waveguides, mode converters from the operating mode into the TE01 mode and back again are necessary. Experimental results for the 30 GHz valves developed for the CLIC Test Facility 3 (CTF3) a...

Development of the RF cavity for the SKKUCY-9 compact cyclotron

International Nuclear Information System (INIS)

Shin, Seungwook; Lee, Jongchul; LEE, Byeong-No; Ha, Donghyup; Namgoong, Ho; Chai, Jongseo

2015-01-01

A 9 MeV compact cyclotron, named SKKUCY-9, for a radiopharmaceutical compound especially fludeoxyglucose (FDG) production for a positron emission tomography (PET) machine was developed at Sungkyunkwan University. H − ions which are produced from a Penning Ionization Gauge(PIG) ion source, travel through a normal conducting radio frequency (RF) cavity which operates at 83.2 MHz for an acceleration and electro-magnet for a beam focusing until the ions acquire energy of about 9 MeV. For installation at a small local hospital, our SKKUCY-9 cyclotron is developed to be compact and light-weight, comparable to conventional medical purpose cyclotrons. For compactness, we adapted a deep valley and large angle hill type for the electro-magnet design. Normally a RF cavity is installed inside of the empty space of the magnet valley region, which is extremely small in our case. We faced problems such as difficulties of installing the RF cavity, low Q-value. Despite of those difficulties, a compact RF cavity and its system including a RF power coupler to feed amplified RF power to the RF cavity and a fine tuner to compensate RF frequency variations was successfully developed and tested

Development of the RF cavity for the SKKUCY-9 compact cyclotron

Science.gov (United States)

Shin, Seungwook; Lee, Jongchul; LEE, Byeong-No; Ha, Donghyup; Namgoong, Ho; Chai, Jongseo

2015-09-01

A 9 MeV compact cyclotron, named SKKUCY-9, for a radiopharmaceutical compound especially fludeoxyglucose (FDG) production for a positron emission tomography (PET) machine was developed at Sungkyunkwan University. H- ions which are produced from a Penning Ionization Gauge(PIG) ion source, travel through a normal conducting radio frequency (RF) cavity which operates at 83.2 MHz for an acceleration and electro-magnet for a beam focusing until the ions acquire energy of about 9 MeV. For installation at a small local hospital, our SKKUCY-9 cyclotron is developed to be compact and light-weight, comparable to conventional medical purpose cyclotrons. For compactness, we adapted a deep valley and large angle hill type for the electro-magnet design. Normally a RF cavity is installed inside of the empty space of the magnet valley region, which is extremely small in our case. We faced problems such as difficulties of installing the RF cavity, low Q-value. Despite of those difficulties, a compact RF cavity and its system including a RF power coupler to feed amplified RF power to the RF cavity and a fine tuner to compensate RF frequency variations was successfully developed and tested.

Intra-observer and interobserver reliability ofOne Leg Stand Test as a measure of posturalbalance in low back pain patients

DEFF Research Database (Denmark)

Maribo, Thomas; Iversen, Elena; Andersen, Niels Trolle

2009-01-01

Objective: To determine the absolute and relative reliability of intra-observer and interobserver To determine the absolute and relative reliability of intra-observer and interobserver measurements of postural balance using the One Leg Stand Test in patients with low back pain. Patients and methods...... to stand for the maximum time, and no further analysis was done. Eyes closed: intra-observer reliability was tested in 21 patients; absolute reliability showed a standard error of the measurement (SEM) of 2.48 s and a minimal detectable change (MDC) of 6.88. The relative reliability was acceptable...... with an intra class correlation coefficient (ICC) of 0.86. Interobserver reliability was tested in 27 patients; absolute reliability showed a SEM of 1.42 s and a MDC of 3.95. The relative reliability was acceptable with an ICC of 0.91. Conclusions: The One Leg Stand Test can be used to test postural balance...

High gradient test of the C-band choke-mode type accelerating structure

International Nuclear Information System (INIS)

Inagaki, T.; Shintake, T.; Baba, H.; Togawa, K.; Onoe, K.; Marechal, X.; Takashima, T.; Takahashi, S.; Matsumoto, H.

2004-01-01

The C-band (5712 MHz) choke-mode type accelerating structure will be used for SPring-8 Compact SASE-FEL Source (SCSS). To make the accelerator length short, we designed the field gradient as high as 40 MV/m. Since it is higher gradient than other traditional electron accelerators, we have to carefully check its performance (RF breakdown, dark current emission, etc.) in the high gradient test stand. The first experiment will be scheduled in this summer. In this paper, we will describe the preparation progress for the test. (author)

First environmental data from the EUV engineering test stand

Science.gov (United States)

Klebanoff, Leonard E.; Malinowski, Michael E.; Grunow, Philip A.; Clift, W. Miles; Steinhaus, Chip; Leung, Alvin H.; Haney, Steven J.

2001-08-01

The first environmental data from the Engineering Test Stand (ETS) has been collected. Excellent control of high-mass hydrocarbons has been observed. This control is a result of extensive outgas testing of components and materials, vacuum compatible design of the ETS, careful cleaning of parts and pre-baking of cables and sub assemblies where possible, and clean assembly procedures. As a result of the hydrocarbon control, the residual ETS vacuum environment is rich in water vapor. Analysis of witness plate data indicates that the ETS environment does not pose a contamination risk to the optics in the absence of EUV irradiation. However, with EUV exposure, the water rich environment can lead to EUV- induced water oxidation of the Si-terminated Mo/Si optics. Added ethanol can prevent optic oxidation, allowing carbon growth via EUV cracking of low-level residual hydrocarbons to occur. The EUV environmental issues are understood, mitigation approaches have been validated, and EUV optic contamination appears to be manageable.

Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC photo-injector energy upgrade

CERN Document Server

Alesini, D.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Gallo, A.; Lollo, V.; Marcellini, F.; Higo, T.; Kakihara, K.; Matsumoto, S.; Campogiani, G.; Mostacci, A.; Palumbo, L.; Persichelli, S.; Spizzo, V.; Verdú-Andrés, S.

2011-01-01

The energy upgrade of the SPARC photo-injector from 160 to more than 260 MeV will be done by replacing a low gradient 3m S-Band structure with two 1.4m high gradient C-band structures. The structures are travelling wave, constant impedance sections, have symmetric waveguide input couplers and have been optimized to work with a SLED RF input pulse. A prototype with a reduced number of cells has been fabricated and tested at high power in KEK (Japan) giving very good performances in terms of breakdown rates (10^6 bpp/m) at high accelerating gradient (>50 MV/m). The paper illustrates the design criteria of the structures, the fabrication procedure and the high power RF test results.

Fall risk screening in the elderly: A comparison of the minimal chair height standing ability test and 5-repetition sit-to-stand test.

Science.gov (United States)

Reider, Nadia; Gaul, Catherine

2016-01-01

Successfully identifying older adults with a high risk of falling can be complicated, time consuming and not feasible in daily medical practice. This study compared the effectiveness of the Minimal Chair Height Standing Ability Test (MCHSAT) and 5-repetition sit-to-stand tst (5R-STS) as fall risk-screening instruments for the elderly. 167 community-dwelling older adults (mean age=83.6±7.3years) were interviewed for demographics, fall history, cognition, and mobility status. MCHSAT performance was assessed using a chair whose seat height was modifiable by increments of 5cm, starting at 47cm and lowering after each successful attempt. 5R-STS performance was assessed by recording the time it took to rise and sit back down five consecutive times from a chair of 47cm high. Operating Receiving Characteristic (ROC) curves and Area under the Curve (AUC) were calculated for each test as well as for sub-groups of participants classified based on medical comorbidities (e.g. cardiac disease/stroke, lower limb arthritis). The MCHSAT and 5R-STS were equally effective fall-risk screening instruments for the overall population (AUC (95% CI)=0.72 (0.63-0.82) and 0.73(0.64-0.81) respectively). The 5R-STS was more effective than the MCHSAT for participants suffering from lower limb arthritis (AUC (95% CI)=0.81(0.70-0.92) and 0.71(0.58-0.85) respectively) while the opposite was true for participants with a history of cardiac disease or stroke (AUC (95% CI)=0.59 (0.44-0.80) and 0.65 (0.47-0.84) respectively). Due to their simplicity and quick administration time, the MCHSAT and 5R-STS are equally suitable for implementation in clinical settings. Copyright © 2016. Published by Elsevier Ireland Ltd.

JET ({sup 3}He)-D scenarios relying on RF heating: survey of selected recent experiments

Energy Technology Data Exchange (ETDEWEB)

Van Eester, D; Lerche, E; Andrew, Y; Biewer, T M; Casati, A; Crombe, K; De la Luna, E; Ericsson, G; Felton, R; Giacomelli, L; Giroud, C; Hawkes, N; Hellesen, C; Hjalmarsson, A; Joffrin, E; Kaellne, J; Kiptily, V; Lomas, P; Mantica, P; Marinoni, A [JET-EFDA Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)] (and others)

2009-04-15

Recent JET experiments have been devoted to the study of ({sup 3}He)-D plasmas involving radio frequency (RF) heating. This paper starts by discussing the RF heating efficiency theoretically expected in such plasmas, covering both relevant aspects of wave and of particle dynamics. Then it gives a concise summary of the main conclusions drawn from recent experiments that were either focusing on studying RF heating physics aspects or that were adopting RF heating as a tool to study plasma behavior. Depending on the minority concentration chosen, different physical phenomena are observed. At very low concentration (X[{sup 3}He] < 1%), energetic tails are formed which trigger MHD activity and result in loss of fast particles. Alfven cascades were observed and gamma ray tomography indirectly shows the impact of sawtooth crashes on the fast particle orbits. Low concentration (X[{sup 3}He] < 10%) favors minority heating while for X[{sup 3}He] >> 10% electron mode conversion damping becomes dominant. Evidence for the Fuchs et al standing wave effect (Fuchs et al 1995 Phys. Plasmas 2 1637-47) on the absorption is presented. RF induced deuterium tails were observed in mode conversion experiments with large X[{sup 3}He] ({approx}18%). As tentative modeling shows, the formation of these tails can be explained as a consequence of wave power absorption by neutral beam particles that efficiently interact with the waves well away from the cold D cyclotron resonance position as a result of their substantial Doppler shift. As both ion and electron RF power deposition profiles in ({sup 3}He)-D plasmas are fairly narrow-giving rise to localized heat sources-the RF heating method is an ideal tool for performing transport studies. Various of the experiments discussed here were done in plasmas with internal transport barriers (ITBs). ITBs are identified as regions with locally reduced diffusivity, where poloidal spinning up of the plasma is observed. The present know-how on the role of

Development of a large proton accelerator for innovative researches; development of high power RF source

Energy Technology Data Exchange (ETDEWEB)

Chung, K. H.; Lee, K. O.; Shin, H. M.; Chung, I. Y. [KAPRA, Seoul (Korea); Kim, D. I. [Inha University, Incheon (Korea); Noh, S. J. [Dankook University, Seoul (Korea); Ko, S. K. [Ulsan University, Ulsan (Korea); Lee, H. J. [Cheju National University, Cheju (Korea); Choi, W. H. [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

2002-05-01

This study was performed with objective to design and develop the KOMAC proton accelerator RF system. For the development of the high power RF source for CCDTL(coupled cavity drift tube linac), the medium power RF system using the UHF klystron for broadcasting was integrated and with this RF system we obtained the basic design data, operation experience and code-validity test data. Based on the medium power RF system experimental data, the high power RF system for CCDTL was designed and its performed was analyzed. 16 refs., 64 figs., 27 tabs. (Author)

Characteristic performance of radio-frequency(RF) plasma heating using inverter RF power supplies

International Nuclear Information System (INIS)

Imai, Takahiro; Uesugi, Yoshihiko; Takamura, Shuichi; Sawada, Hiroyuki; Hattori, Norifumi

2000-01-01

High heat flux plasma are produced by high powe (∼14 kW) ICRF heating using inverter power supplies in the linear divertor simulator NAGDIS-II. The power flow of radiated rf power is investigated by a calorimetric method. Conventional power calculation using antenna voltage and current gives that about 70% of the rf power is radiated into the plasma. But increase of the heat load at the target and anode is about 10% of the rf power. Through this experiment, we find that about half of the rf power is lost at the antenna surface through the formation of rf induced sheath. And about 30% of the power is lost into the vacuum vessel through the charge exchange and elastic collision of ions with neutrals. (author)

R and D of control system of compact self-bunching RF gun test facility

International Nuclear Information System (INIS)

Pang Jian; Pei Yuanji; Huang Guirong; Wang Jinxiang

2010-01-01

An experimental device was recently constructed for testing the beam characteristics of a compact self-bunching RF gun at the National Synchrotron Radiation Laboratory. It designs an independent monitor and control system for the experimental device so as not to disturb the operation of 200MeV LINAC. According to the three-level architecture of a general control scheme, the proposed system consists of circuits that execute kernel control, photosignal emission/reception, and switch values input/output, respectively. It performs timing control, device status monitoring as well as interlock protection, and it can be remotely operated with the assistance of PC software. Testing results show that our system achieves the specified performance and meets the requirement of experimental device stably and reliably. Our proposed system can also be applied to control other small-scale accelerators. (authors)

Simulations of S-band RF gun with RF beam control

Science.gov (United States)

Barnyakov, A. M.; Levichev, A. E.; Maltseva, M. V.; Nikiforov, D. A.

2017-08-01

The RF gun with RF control is discussed. It is based on the RF triode and two kinds of the cavities. The first cavity is a coaxial cavity with cathode-grid assembly where beam bunches are formed, the second one is an accelerating cavity. The features of such a gun are the following: bunched and relativistic beams in the output of the injector, absence of the back bombarding electrons, low energy spread and short length of the bunches. The scheme of the injector is shown. The electromagnetic field simulation and longitudinal beam dynamics are presented. The possible using of the injector is discussed.

Rare Variants in Genes Encoding MuRF1 and MuRF2 Are Modifiers of Hypertrophic Cardiomyopathy

Directory of Open Access Journals (Sweden)

Ming Su

2014-05-01

Full Text Available Modifier genes contribute to the diverse clinical manifestations of hypertrophic cardiomyopathy (HCM, but are still largely unknown. Muscle ring finger (MuRF proteins are a class of muscle-specific ubiquitin E3-ligases that appear to modulate cardiac mass and function by regulating the ubiquitin-proteasome system. In this study we screened all the three members of the MuRF family, MuRF1, MuRF2 and MuRF3, in 594 unrelated HCM patients and 307 healthy controls by targeted resequencing. Identified rare variants were confirmed by capillary Sanger sequencing. The prevalence of rare variants in both MuRF1 and MuRF2 in HCM patients was higher than that in control subjects (MuRF1 13/594 (2.2% vs. 1/307 (0.3%, p = 0.04; MuRF2 22/594 (3.7% vs. 2/307 (0.7%; p = 0.007. Patients with rare variants in MuRF1 or MuRF2 were younger (p = 0.04 and had greater maximum left ventricular wall thickness (p = 0.006 than those without such variants. Mutations in genes encoding sarcomere proteins were present in 19 (55.9% of the 34 HCM patients with rare variants in MuRF1 and MuRF2. These data strongly supported that rare variants in MuRF1 and MuRF2 are associated with higher penetrance and more severe clinical manifestations of HCM. The findings suggest that dysregulation of the ubiquitin-proteasome system contributes to the pathogenesis of HCM.

rf impedance of the accelerating beam gap and its significance to the TRIUMF rf system

International Nuclear Information System (INIS)

Poirier, R.

1979-03-01

The rf system at TRIUMF is now operating with the highest Q, the lowest rf leakage into the beam gap, the best voltage stability, and the lowest resonator strongback temperatures ever measured since it was first put into operation. This paper describes the calculation of the rf impedance of the beam gap and its correlation to the rf problems encountered, which eventually led to modifications to the flux guides and resonator tips to accomplish the improved operation of the rf system

RF feedback development for the PEP-II B Factory

Energy Technology Data Exchange (ETDEWEB)

Corredoura, P.; Sapozhnikov, L.; Tighe, R.

1994-06-01

In PEP-II heavy beam loading along with a relatively long revolution period combine to strongly drive lower coupled-bunch modes through interaction with the fundamental cavity mode. Feedback techniques can be applied to reduce the cavity impedance seen by the beam. Several RF feedback loops are planned to reduce the growth rates down to a level which can be damped by the relatively low power bunch-by-bunch longitudinal feedback system. This paper describes the RF feedback loops as well as hardware tests using a 500 kW klystron, analog and digital feedback loops, and a low power test cavity.

RF feedback development for the PEP-II B Factory

International Nuclear Information System (INIS)

Corredoura, P.; Sapozhnikov, L.; Tighe, R.

1994-06-01

In PEP-II heavy beam loading along with a relatively long revolution period combine to strongly drive lower coupled-bunch modes through interaction with the fundamental cavity mode. Feedback techniques can be applied to reduce the cavity impedance seen by the beam. Several RF feedback loops are planned to reduce the growth rates down to a level which can be damped by the relatively low power bunch-by-bunch longitudinal feedback system. This paper describes the RF feedback loops as well as hardware tests using a 500 kW klystron, analog and digital feedback loops, and a low power test cavity

Modelling of Spring Constant and Pull-down Voltage of Non-uniform RF MEMS Cantilever Incorporating Stress Gradient

Directory of Open Access Journals (Sweden)

Shimul Chandra SAHA

2008-11-01

Full Text Available We have presented a model for spring constant and pull-down voltage of a non-uniform radio frequency microelectromechanical systems (RF MEMS cantilever that works on electrostatic actuation. The residual stress gradient in the beam material that may arise during the fabrication process is also considered in the model. Using basic force deflection calculation of the suspended beam, a stand-alone model for the spring constant and pull-down voltage of the non-uniform cantilever is developed. To compare the model, simulation is performed using standard Finite Element Method (FEM analysis tolls from CoventorWare. The model matches very well with the FEM simulation results. The model will offer an efficient means of design, analysis, and optimization of RF MEMS cantilever switches.

Test of four stand growth simulators for the northeastern United States

Science.gov (United States)

Thomas M. Schuler; David A. Marquis; Richard L. Ernst; Brian T. Simpson; Brian T. Simpson

1993-01-01

Evaluates SILVAH, FIBER, NE-TWIGS, and OAKSIM, simulators commonly used in the northeastern United States, by comparing predicted stand development with actual stand development records for periods ranging from 15 to 50 years. Results varied with stand parameter, forest type, projection length, and geographic area. Except in the spruce-fir forest type where FIBER...

An experimental test of the causes of forest growth decline with stand age.

Science.gov (United States)

Michael G. Ryan; Dan Binkley; James H. Fownes; Christian Giardina; Randy S. Senock

2004-01-01

The decline in aboveground wood production after canopy closure in even-aged forest stands is a common pattern in forests, but clear evidence for the mechanism causing the decline is lacking. The problem is fundamental to forest biology, commercial forestry (the decline sets the rotation age), and to carbon storage in forests. We tested three hypotheses...

A Test Model in a RF Anechoic Chamber for the Application of Wi-Fi Communication in Korean Operating NPPs

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Sik; Kim, Min Seok; Ryu, Ho Sun; Ye, Song Hae; Lee, Gwang Dae [KHNP, Daejeon (Korea, Republic of)

2014-08-15

The objective of this study is to make a test model and confirm its effectiveness in a radio frequency (RF) anechoic chamber before conducting a field test in Korean operating NPPs for use of Wi-Fi communication technology. This paper is focused on electromagnetic/radio-frequency interference (EMI/RFI) issue and discusses a methodology and its test result for overcoming that issue. Whenever wireless communication is performed between an access point (AP) and a smart phone, EMI/RFI problem always happens around those devices. It is necessary to decide how many wireless devices local workers will use and select what facilities and systems to protect from EMI/RFI, which are so-called EMI/RFI sensitive equipment. The number of wireless devices was decided as many as possible in the area where those devices could be used, and some sensitive equipment that shall not malfunction under electromagnetic environment were chosen. The test bed which considered above mentioned conditions was constructed and an experiment was carried out inside a radio-frequency anechoic chamber. Comparing with the allowable operating envelopes for electromagnetic level from RG-1.180, each maximum level of the test results acquired from a RF anechoic chamber is not over the limit even in case of considering the maximum local workers' usage. This result shows that it is highly likely that Wi-Fi communication can be used without any problem if sensitive equipment has observed the electromagnetic susceptibility limit of RG-1.180.

Performing a Large-Scale Modal Test on the B2 Stand Crane at NASA's Stennis Space Center

Science.gov (United States)

Stasiunas, Eric C.; Parks, Russel A.; Sontag, Brendan D.

2018-01-01

A modal test of NASA's Space Launch System (SLS) Core Stage is scheduled to occur at the Stennis Space Center B2 test stand. A derrick crane with a 150-ft long boom, located at the top of the stand, will be used to suspend the Core Stage in order to achieve defined boundary conditions. During this suspended modal test, it is expected that dynamic coupling will occur between the crane and the Core Stage. Therefore, a separate modal test was performed on the B2 crane itself, in order to evaluate the varying dynamic characteristics and correlate math models of the crane. Performing a modal test on such a massive structure was challenging and required creative test setup and procedures, including implementing both AC and DC accelerometers, and performing both classical hammer and operational modal analysis. This paper describes the logistics required to perform this large-scale test, as well as details of the test setup, the modal test methods used, and an overview and application of the results.

Control and performance improvements of a pulse compressor in use for testing accelerating structures at high power

Directory of Open Access Journals (Sweden)

Benjamin Woolley

2017-10-01

Full Text Available New developments relating to compact X-band, SLED-I type pulse compressors being developed at CERN for testing high gradient structures are described. Pulse compressors of interest take rf pulses from one or more high power klystrons with duration typically >1.5  μs and deliver up to 5 times the input power for a shorter duration <250  ns. Time domain models for pulse compressor operation with low level rf (LLRF control have been developed. Input drive amplitude and phase for each pulse is evolved with a control algorithm from the pulse compressor output for previous pulses. The goal is to deliver precise amplitude for pulses to test stands and precise amplitude and phase for pulses to accelerator systems. Control algorithms have been developed and validated experimentally.

Intermediate quality control tests in the development of a superconducting RF cryomodule for CW operation

Science.gov (United States)

Pattalwar, Shrikant; Jones, Thomas; Strachan, John; Bate, Robert; Davies, Phil; McIntosh, Peter

2012-06-01

Through an international cryomodule collaboration, ASTeC at Daresbury Laboratory has taken the primary responsibility in leading the development of an optimised Superconducting RF (SRF) cryomodule, operating in CW mode for energy recovery facilities and other high duty cycle accelerators. For high beam current operation, Higher Order Mode (HOM) absorbers are critical components of the SRF Cryomodule, ensuring excessive heating of the accelerating structures and beam instabilities are effectively managed. This paper describes some of the cold tests conducted on the HOM absorbers and other critical components during the construction phase, to ensure that the quality and reliable cryomodule performance is maintained.

Rf and space-charge induced emittances in laser-driven rf guns

International Nuclear Information System (INIS)

Kim, Kwang-Je; Chen, Yu-Jiuan.

1988-10-01

Laser-driven rf electron guns are potential sources of high-current, low-emittance, short bunch-length electron beams, which are required for many advanced accelerator applications, such as free-electron lasers and injectors for high-energy machines. In such guns the design of which was pioneered at Los Alamos National Laboratory and which is currently being developed at several other laboratories, a high-power laser beam illuminates a photo-cathode surface placed on an end wall of an rf cavity. The main advantages of this type of gun are that the time structure of the electron beam is controlled by the laser, eliminating the need for bunchers, and that the electric field in rf cavities can be made very strong, so that the effects due to space-charge repulsion can be minimized. In this paper, we present an approximate but simple analysis for the transverse and longitudinal emittances in rf guns that takes into account both the time variation of the rf field and the space-charge effect. The results are compared and found to agree well with those from simulation. 7 refs., 6 figs

Instrumentation and control system for the AT-2 accelerator test stand

International Nuclear Information System (INIS)

Wadlinger, E.A.; Holtkamp, D.B.; Holt, H.D.

1984-01-01

A data-driven subroutine package, written for our accelerator test stand (ATS), is described. This flexible package permits the rapid writing and modifying of data acquisition, control, and analysis programs for the many diverse experiments performed on the ATS. These structurally simple and easy to maintain routines help to control administratively the integrity of the ATS through the use of the database. Our operating experience indicates that the original design goals have been met. We describe the subroutines, database, and our experiences with this system

Barrier rf systems in synchrotrons

International Nuclear Information System (INIS)

Bhat, Chandra M.

2004-01-01

Recently, many interesting applications of the barrier RF system in hadron synchrotrons have been realized. A remarkable example of this is the development of longitudinal momentum mining and implementation at the Fermilab Recycler for extraction of low emittance pbars for the Tevatron shots. At Fermilab, we have barrier RF systems in four different rings. In the case of Recycler Ring, all of the rf manipulations are carried out using a barrier RF system. Here, the author reviews various uses of barrier rf systems in particle accelerators including some new schemes for producing intense proton beam and possible new applications

Design of an L-band normally conducting RF gun cavity for high peak and average RF power

Energy Technology Data Exchange (ETDEWEB)

Paramonov, V., E-mail: paramono@inr.ru [Institute for Nuclear Research of Russian Academy of Sciences, 60-th October Anniversary prospect 7a, 117312 Moscow (Russian Federation); Philipp, S. [Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Rybakov, I.; Skassyrskaya, A. [Institute for Nuclear Research of Russian Academy of Sciences, 60-th October Anniversary prospect 7a, 117312 Moscow (Russian Federation); Stephan, F. [Deutsches Elektronen-Synchrotron DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

2017-05-11

To provide high quality electron bunches for linear accelerators used in free electron lasers and particle colliders, RF gun cavities operate with extreme electric fields, resulting in a high pulsed RF power. The main L-band superconducting linacs of such facilities also require a long RF pulse length, resulting in a high average dissipated RF power in the gun cavity. The newly developed cavity based on the proven advantages of the existing DESY RF gun cavities, underwent significant changes. The shape of the cells is optimized to reduce the maximal surface electric field and RF loss power. Furthermore, the cavity is equipped with an RF probe to measure the field amplitude and phase. The elaborated cooling circuit design results in a lower temperature rise on the cavity RF surface and permits higher dissipated RF power. The paper presents the main solutions and results of the cavity design.

Cryogenic system for TRISTAN superconducting RF cavity

International Nuclear Information System (INIS)

Hosoyama, K.; Hara, K.; Kabe, A.; Kojima, Yuuji; Ogitsu, T.; Sakamoto, Y.; Kawamura, S.; Ishimaru, Y.

1990-01-01

A cryogenic system consisting of a helium refrigerator (4 kW at 4.4 K) and a liquid helium distribution transfer system for TRISTAN 508 MHz 32 x 5-cell superconducting RF cavities was designed and constructed. After the performance test of the cryogenic system, 16 x 5-cell superconducting RF cavities in 8 cryostats were installed in underground TRISTAN electron-positron collider and connected to the helium refrigerator on the ground level through the transfer line (total length about 330 m) and cooled by liquid helium pool boiling in parallel. The cryogenic system and its operation experience are described. (author)

The study of fix composite panel and steel plates on testing stand

Science.gov (United States)

Wróbel, A.; Płaczek, M.; Wachna, M.

2016-08-01

In this paper the practical possibilities of strength verification analysis of composite materials used in the manufacture of selected components of railway wagons are presented. Real laboratory stand for measurements in a scale controlled by PLC controller were made. The study of different types of connections of composite materials with sheet metal is presented. In one of the chapter of this paper principles construction of testing stand with pneumatic cylinder were presented. Mainly checking of displacements and stresses generated on the sheet as a result of pneumatic actuators load for composite boards was carried out. The use of the controller with operating panel allows to easy programming testing cycle. The user can define the force generated by the actuator by change of air pressure in cylinder. Additionally the location of acting cylinders and their jump can be changed by operator. The examination of the volume displacements was done by displacement sensor, and the tensile strain gauge. All parameters are written in CatmanEasy - data acquisition software. This article presents the study of stresses and displacements in the composite plates joined with sheet metal, in summary of this article, the authors compare the obtained results with the computer simulation results in the article: "Simulation of stresses in an innovative combination of composite with sheet".

Laser based beam diagnostic for the RAL Front End Test Stand (FETS)

International Nuclear Information System (INIS)

Gabor, C.; Lee, D. A.; Pozimski, J. K.; Letchford, A.

2007-01-01

For the diagnostic of high power particle beams, non-destructive measurement devices provide minimum influence on the beam and avoid various problems in connection with the high power density on surfaces. An H- ion beam offers the opportunity of non destructive beam diagnostics based on the effect of photo detachment. By the interaction of light with H- ions, the additional electron can be detached and a small number of neutrals will be produced. An additional magnetic dipole field can then be used to separate the detached electrons and neutrals from the ions. Using an integral detector the spatial distribution of the beam ion density can be derived, while the use of a spatial resolving detector enables to determine the phase space distribution. To investigate the measurement principle of the latter, a test stand was set up at the IAP in Frankfurt. This system will now be adopted to the requirements of the Front End Test Stand at CCLRC/ RAL. The aim of this FETS is to demonstrate a chopped H- beam of 60mA at 3MeV and 50pps with sufficiently high beam quality. The paper will present a detailed description of the proposed set up at RAL and discuss several results of simulations and experimental data gained in Frankfurt

Design, fabrication and low power RF testing of a prototype beta=1, 1050 MHz cavity developed for electron linac

International Nuclear Information System (INIS)

Sarkar, S.; Mondal, J.; Mittal, K.C.

2013-01-01

A single cell 1050 MHz β = 1 elliptical cavity has been designed for possible use in High energy electron accelerator. A prototype Aluminium cavity has been fabricated by die punch method and low power testing of the cavity has been carried out by using VNA. The fundamental mode frequency of the prototype cavity is found out to be 1051.38 MHz and Q (loaded) and Q0 values corresponding to 2 modes are 8439 and 10013 respectively. Cell to cell coupling coefficient is 1.82 % from measurement which matches with the designed value (1.84%). The higher order mode frequencies are also measured and electric field of the cavity is confirmed by bead pull method. Low power RF measurements on the prototype cavity indicate that the critical RF parameters (Qo, f, Kc etc) for the cavity are consistent with the designed value. (author)

Energy-efficient operation of a booster RF system for Taiwan light source operated in top-up mode

International Nuclear Information System (INIS)

Yeh, Meng-Shu; Wang, Chaoen; Chang, Lung-Hai; Chung, Fu-Tsai; Yu, Tsung-Chi; Lin, Ming-Chyuan; Chen, Ling-Jhen; Yang, Tz-Te; Chang, Mei-Hsia; Lin, Yu-Han; Tsai, Ming-Hsun; Lo, Chih-Hung; Liu, Zong-Kai

2015-01-01

Contemporary light sources operate in a top-up mode to maintain their photon intensity quasi-constant so as to improve significantly the thermal stability of the photon beam and to maximize ultimately the average photon flux at a designed maximum operational beam current. Operating in a top-up mode requires frequent beam injection from the synchrotron booster to the storage ring of the light source, but the injection intervals occupy only a tiny portion of the operational time of the integrated machine. To maintain a high operational reliability, the booster RF system practically operates necessarily under injection conditions around the clock and consumes full electric power whether during top-up injection or not. How to decrease the power consumption of the booster RF system during its stand-by time but not to sacrifice the reliability and availability of the RF system is obviously of fundamental interest for routine operation of the light source in a top-up mode. Here, an energy-efficient operation of a booster RF system adaptive to top-up operation of a light source is proposed that has been developed, realized and integrated into the booster RF system of the Taiwan Light Source (TLS), and routinely operated since the end of year 2008. The klystron cathode current and RF gap voltage of the booster's accelerating RF cavity are both periodically modulated to adapt the injection rhythm during top-up operation, which results in decreased consumption of electric power of the booster RF system by more than 78%. The impact on the reliability and availability of the booster RF system has been carefully monitored during the past five operational years, delivering more than 5000 h scheduled user beam time per year. The booster RF system retains its excellent reliability and availability as previously. Neither a decrease of the service time nor an induced reliability issue from the klystron or any high-power high-voltage component of the transmitter has been

rf streak camera based ultrafast relativistic electron diffraction.

Science.gov (United States)

Musumeci, P; Moody, J T; Scoby, C M; Gutierrez, M S; Tran, T

2009-01-01

We theoretically and experimentally investigate the possibility of using a rf streak camera to time resolve in a single shot structural changes at the sub-100 fs time scale via relativistic electron diffraction. We experimentally tested this novel concept at the UCLA Pegasus rf photoinjector. Time-resolved diffraction patterns from thin Al foil are recorded. Averaging over 50 shots is required in order to get statistics sufficient to uncover a variation in time of the diffraction patterns. In the absence of an external pump laser, this is explained as due to the energy chirp on the beam out of the electron gun. With further improvements to the electron source, rf streak camera based ultrafast electron diffraction has the potential to yield truly single shot measurements of ultrafast processes.

Construction of a test stand for the measurement of the light output uniformity of CALIFA crystals

Energy Technology Data Exchange (ETDEWEB)

Susenburger, Markus; Ignatov, Alexander; Kroell, Thorsten [Technische Universitaet Darmstadt, Darmstadt (Germany)

2016-07-01

Currently, the Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is under construction. One experiment at GSI and FAIR is called Reactions with Relativistic Radioactive Beams (R{sup 3}B). A key component of the R{sup 3}B is the CALorimeter for In Flight detection of γ-rays and light charged pArticles (CALIFA), which will surround the R{sup 3}B target chamber and will be capable of the detection of γ-rays in a wide energy range from 100 keV to 30 MeV as well as of light charged particles. CALIFA is built out of two parts, the so called CALIFA barrel and CALIFA endcap. The barrel consists of 1952 CsI(Tl) detector crystals which have to fulfill several specifications. One of these specifications is the uniformity of the light output. Depending on the location of the deposited energy, the crystal's light output varies due to optical focusing effects. This behavior can be manipulated by lapping the crystal's surface. The aim of this work is the development of a test stand which will check if the crystals match the requirements according to the light output uniformity. Because of the large number of crystals needed to be tested, the stand automates the test procedure, which guarantees comparable test measurement for all crystals. The development and construction of this stand is reported.

Beam-Based Procedures for RF Guns

CERN Document Server

Krasilnikov, Mikhail; Grabosch, H J; Hartrott, Michael; Hui Han, Jang; Miltchev, Velizar; Oppelt, Anne; Petrosyan, Bagrat; Staykov, Lazar; Stephan, Frank

2005-01-01

A wide range of rf photo injector parameters has to be optimized in order to achieve an electron source performance as required for linac based high gain FELs. Some of the machine parameters can not be precisely controlled by direct measurements, whereas the tolerance on them is extremely tight. Therefore, this should be met with beam-based techniques. Procedures for beam-based alignment (BBA) of the laser on the photo cathode as well as solenoid alignment have been developed. They were applied at the Photo Injector Test facility at DESY Zeuthen (PITZ) and at the photo injector of the VUV-FEL at DESY Hamburg. A field balance of the accelerating mode in the 1 ½ cell gun cavity is one of the key beam dynamics issues of the rf gun. Since no direct field measurement in the half and full cell of the cavity is available for the PITZ gun, a beam-based technique to determine the field balance has been proposed. A beam-based rf phase monitoring procedure has been developed as well.

THE MURMANSK INITIATIVE - RF: COMPLETING CONSTRUCTION AND START-UP TESTING

International Nuclear Information System (INIS)

CZAJKOWSKI, C.; BOWERMAN, B.S.; DYER, R.S.; SORLIE, A.A.; WESTER, D.

1998-01-01

The Murmansk Initiative - RF was instigated to address Russia's ability to meet the London Convention prohibiting ocean dumping of radioactive waste. The Initiative, under a trilateral agreement, will upgrade an existing low-level liquid radioactive waste treatment facility, increasing capacity from 1,200 m 3 /year to 5,000 m 3 /year, and expand the capability to treat liquids containing salt (up to 10 g/L). The three parties to the agreement, the Russian Federation, Norway, and the US, have split the costs for the project. All construction has been provided by Russia. Construction of mechanical systems (piping and valves, pumps, sorbent columns, settling tanks, surge tanks) is nearly complete, with instrumentation and control (I+C) systems the last to be installed. Delays to the I+C installation have occurred because changes in system specifications required some additional US-supplied computer control equipment to be purchased, and clearance through customs (both US and Russian) has been slow. Start-up testing has been limited to testing of some isolated sub-systems because of the delays in I+C installation. Final construction activities are also hampered by the current state of the Russian economy. The specific impact has been completion of the cementation unit, which was not funded under the trilateral agreement (but funded by the Russian government). Russian regulatory authorities have stated that final licensing for expanded capacity (5,000 m 3 /year) will not be given until the cementation unit is on-line

Direct RF modulation transmitter, sampling clock frequency setting method for direct RF modulation transmitter

NARCIS (Netherlands)

Fukuda, Shuichi; Nauta, Bram

2013-01-01

PROBLEM TO BE SOLVED: To provide a direct RF modulation transmitter capable of satisfying a radiation level regulation even without providing a SAW filter. SOLUTION: A direct RF modulation transmitter includes: digital/RF converters 105, 106 to which an I digital baseband signal, a Q digital

Direct RF modulation transmitter, sampling clock frequency setting method for direct RF modulation transmitter

NARCIS (Netherlands)

Fukuda, Shuichi; Nauta, Bram

2014-01-01

PROBLEM TO BE SOLVED: To provide a direct RF modulation transmitter capable of satisfying a radiation level regulation even without providing a SAW filter. SOLUTION: A direct RF modulation transmitter includes: digital/RF converters 105, 106 to which an I digital baseband signal, a Q digital

Simulating Urban Growth Using a Random Forest-Cellular Automata (RF-CA Model

Directory of Open Access Journals (Sweden)

Courage Kamusoko

2015-04-01

Full Text Available Sustainable urban planning and management require reliable land change models, which can be used to improve decision making. The objective of this study was to test a random forest-cellular automata (RF-CA model, which combines random forest (RF and cellular automata (CA models. The Kappa simulation (KSimulation, figure of merit, and components of agreement and disagreement statistics were used to validate the RF-CA model. Furthermore, the RF-CA model was compared with support vector machine cellular automata (SVM-CA and logistic regression cellular automata (LR-CA models. Results show that the RF-CA model outperformed the SVM-CA and LR-CA models. The RF-CA model had a Kappa simulation (KSimulation accuracy of 0.51 (with a figure of merit statistic of 47%, while SVM-CA and LR-CA models had a KSimulation accuracy of 0.39 and −0.22 (with figure of merit statistics of 39% and 6%, respectively. Generally, the RF-CA model was relatively accurate at allocating “non-built-up to built-up” changes as reflected by the correct “non-built-up to built-up” components of agreement of 15%. The performance of the RF-CA model was attributed to the relatively accurate RF transition potential maps. Therefore, this study highlights the potential of the RF-CA model for simulating urban growth.

SLAC RF Source Research at X-Band

International Nuclear Information System (INIS)

Sprehn, D.

2003-01-01

X-band klystrons capable of 75 MW and utilizing either solenoidal or Periodic Permanent Magnet (PPM) focusing are undergoing design, fabrication and testing at the Stanford Linear Accelerator Center (SLAC). The klystron development is part of an effort to realize components necessary for the construction of the Next Linear Collider (NLC). SLAC has developed a solenoidal-focused X-band klystron which is currently the workhorse of high power component testing for the NLC. A state-of-the-art modulator will drive eight of these tubes which, in turn, will power an rf distribution system referred to as the ''8-pack'' in order to test these modulators and waveguide components. Eventually, in an interest to save millions of dollars per year in the operational cost of the NLC, these tubes will be replaced by PPM klystrons. The PPM devices built to date which fit this class of operation consist of a variety of 50 MW and 75 MW devices constructed by SLAC, KEK (Tsukuba, Japan ), and industry. These tubes follow from the successful 50 MW PPM design of 1996. Recent testing of this particular tube at wider pulsewidths has reached 50 MW at 55 % efficiency, 2.4 μs and 60 Hz. Two 50 MW PPM klystrons produced by industry have been delivered to SLAC. One of these devices arrived with a vacuum suitable for test. Testing during 2001 revealed a serious, but curious, vacuum response which limited the operation to an rf output of ∼40 MW. A 75 MW PPM klystron prototype was first constructed in 1997 and later modified in 1999 to eliminate oscillations. This tube has reached the NLC design target of 75 MW at 1.5 μs though at a significantly reduced rep rate. Two new 75 MW PPM klystrons were constructed and tested in 2002 after a diode was successfully tested in 2001. The new design was aimed at reducing the cost and increasing the reliability of such high-energy devices. The rf circuit and beam focusing for one of these devices was built by industry and incorporated into one of the tubes

Experimental study of rf pulsed heating

CERN Document Server

Laurent, L; Nantista, C; Dolgashev, V; Higashi, Y; Aicheler, M; Tantawi, S; Wuensch, W

2011-01-01

Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop (R), copper silver, and silver plated co...

Pc based RF control system for the Vincy cyclotron

International Nuclear Information System (INIS)

Samardzic, B.J.; Drndarevic, V.R.

1999-01-01

The concept and design procedure for the RF control system of the VINCY cyclotron are described. Special attention has been paid to the choice of computer support of this system. The merits and limitations of the chosen solution have been analyzed. A PC type computer has been selected as the platform for performing the functions of initiation, control, and supervision of the RF system. The integration of the hardware is carried out by direct connection to the PC bus via standard communication interfaces. The system software operates under a graphic oriented Windows operating system applying the modern concept of virtual instrumentation. The application of this concept allowed considerable simplification of the operator-RF system interaction and resulted in additional flexibility of the software to further extensions or modifications of the system. The selected open architecture of the computer platform allows a simple and economic upgrading of the realized system in accordance with future requirements. Tests of the realized RF control system prototype are in progress. (authors)

Reliability and validity of a talent identification test battery for seated and standing Paralympic throws.

Science.gov (United States)

Spathis, Jemima Grace; Connick, Mark James; Beckman, Emma Maree; Newcombe, Peter Anthony; Tweedy, Sean Michael

2015-01-01

Paralympic throwing events for athletes with physical impairments comprise seated and standing javelin, shot put, discus and seated club throwing. Identification of talented throwers would enable prediction of future success and promote participation; however, a valid and reliable talent identification battery for Paralympic throwing has not been reported. This study evaluates the reliability and validity of a talent identification battery for Paralympic throws. Participants were non-disabled so that impairment would not confound analyses, and results would provide an indication of normative performance. Twenty-eight non-disabled participants (13 M; 15 F) aged 23.6 years (±5.44) performed five kinematically distinct criterion throws (three seated, two standing) and nine talent identification tests (three anthropometric, six motor); 23 were tested a second time to evaluate test-retest reliability. Talent identification test-retest reliability was evaluated using Intra-class Correlation Coefficient (ICC) and Bland-Altman plots (Limits of Agreement). Spearman's correlation assessed strength of association between criterion throws and talent identification tests. Reliability was generally acceptable (mean ICC = 0.89), but two seated talent identification tests require more extensive familiarisation. Correlation strength (mean rs = 0.76) indicated that the talent identification tests can be used to validly identify individuals with competitively advantageous attributes for each of the five kinematically distinct throwing activities. Results facilitate further research in this understudied area.

Fluorescent screens and image processing for the APS linac test stand

International Nuclear Information System (INIS)

Berg, W.; Ko, K.

1992-01-01

A fluorescent screen was used to monitor relative beam position and spot size of a 56-MeV electron beam in the linac test stand. A chromium doped alumina ceramic screen inserted into the beam was monitored by a video camera. The resulting image was captured using a frame grabber and stored into memory. Reconstruction and analysis of the stored image was performed using PV-WAVE. This paper will discuss the hardware and software implementation of the fluorescent screen and imaging system. Proposed improvements for the APS linac fluorescent screens and image

High Power RF Transmitters for ICRF Applications on EAST

International Nuclear Information System (INIS)

Mao Yuzhou; Yuan Shuai; Zhao Yanping; Zhang Xinjun; Chen Gen; Cheng Yan; Wang Lei; Ju Songqing; Deng Xu; Qin Chengming; Yang Lei; Kumazawa, R.

2013-01-01

An Ion Cyclotron Range of Frequency (ICRF) system with a radio frequency (RF) power of 4 × 1.5 MW was developed for the Experimental Advanced Superconducting Tokamak (EAST). High RF power transmitters were designed as a part of the research and development (R and D) for an ICRF system with long pulse operation at megawatt levels in a frequency range of 25 MHz to 70 MHz. Studies presented in this paper cover the following parts of the high power transmitter: the three staged high power amplifier, which is composed of a 5 kW wideband solid state amplifier, a 100 kW tetrode drive stage amplifier and a 1.5 MW tetrode final stage amplifier, and the DC high voltage power supply (HVPS). Based on engineering design and static examinations, the RF transmitters were tested using a matched dummy load where an RF output power of 1.5 MW was achieved. The transmitters provide 6 MW RF power in primary phase and will reach a level up to 12 MW after a later upgrade. The transmitters performed successfully in stable operations in EAST and HT-7 devices. Up to 1.8 MW of RF power was injected into plasmas in EAST ICRF heating experiments during the 2010 autumn campaign and plasma performance was greatly improved.

Design of 250-MW CW RF system for APT

International Nuclear Information System (INIS)

Rees, D.

1997-01-01

The design for the RF systems for the APT (Accelerator Production of Tritium) proton linac will be presented. The linac produces a continuous beam power of 130 MW at 1300 MeV with the installed capability to produce up to a 170 MW beam at 1700 MeV. The linac is comprised of a 350 MHz RFQ to 7 MeV followed in sequence by a 700 MHz coupled-cavity drift tube linac, coupled-cavity linac, and superconducting (SC) linac to 1700 MeV. At the 1700 MeV, 100 mA level the linac requires 213 MW of continuous-wave (CW) RF power. This power will be supplied by klystrons with a nominal output power of 1.0 MW. 237 kystrons are required with all but three of these klystrons operating at 700 MHz. The klystron count includes redundancy provisions that will be described which allow the RF systems to meet an operational availability in excess of 95 percent. The approach to achieve this redundancy will be presented for both the normal conducting (NC) and SC accelerators. Because of the large amount of CW RF power required for the APT linac, efficiency is very important to minimize operating cost. Operation and the RF system design, including in-progress advanced technology developments which improve efficiency, will be discussed. RF system performance will also be predicted. Because of the simultaneous pressures to increase RF system reliability, reduce tunnel envelope, and minimize RF system cost, the design of the RF vacuum windows has become an important issue. The power from a klystron will be divided into four equal parts to minimize the stress on the RF vacuum windows. Even with this reduction, the RF power level at the window is at the upper boundary of the power levels employed at other CW accelerator facilities. The design of a 350 MHz, coaxial vacuum window will be presented as well as test results and high power conditioning profiles. The transmission of 950 kW, CW, power through this window has been demonstrated with only minimal high power conditioning

Performance studies of the vibration wire monitor on the test stand with low energy electron beam

International Nuclear Information System (INIS)

Okabe, Kota; Yoshimoto, Masahiro; Kinsho, Michikazu

2015-01-01

In the high intensity proton accelerator as the Japan Proton Accelerator Research Complex (J-PARC) accelerators, serious radiation and residual dose is induced by a small beam loss such a beam halo. Therefore, diagnostics of the beam halo formation is one of the most important issues to control the beam loss. For the beam halo monitor, the vibration wire monitor (VWM) has a potential for investigating the beam halo and weak beam scanning. The VWM has a wide dynamic range, high resolution and the VWM is not susceptible to secondary electrons and electric noises. We have studied the VWM features as a new beam-halo monitor on the test stand with low energy electron gun. The frequency shift of the irradiated vibration wire was confirmed about wire material and the electron beam profile measured by using the VWM was consistent with the results of the Faraday cup measurement. Also we calculated a temperature distribution on the vibration wire which is irradiated by the electron beam with the numerical simulation. The simulations have been fairly successful in reproducing the transient of the irradiated vibration wire frequency measured by test stand experiments. In this paper, we will report a result of performance evaluation for the VWM on the test stands and discuss the VWM for beam halo diagnostic. (author)

OPAL: prediction of MoRF regions in intrinsically disordered protein sequences.

Science.gov (United States)

Sharma, Ronesh; Raicar, Gaurav; Tsunoda, Tatsuhiko; Patil, Ashwini; Sharma, Alok

2018-06-01

Intrinsically disordered proteins lack stable 3-dimensional structure and play a crucial role in performing various biological functions. Key to their biological function are the molecular recognition features (MoRFs) located within long disordered regions. Computationally identifying these MoRFs from disordered protein sequences is a challenging task. In this study, we present a new MoRF predictor, OPAL, to identify MoRFs in disordered protein sequences. OPAL utilizes two independent sources of information computed using different component predictors. The scores are processed and combined using common averaging method. The first score is computed using a component MoRF predictor which utilizes composition and sequence similarity of MoRF and non-MoRF regions to detect MoRFs. The second score is calculated using half-sphere exposure (HSE), solvent accessible surface area (ASA) and backbone angle information of the disordered protein sequence, using information from the amino acid properties of flanks surrounding the MoRFs to distinguish MoRF and non-MoRF residues. OPAL is evaluated using test sets that were previously used to evaluate MoRF predictors, MoRFpred, MoRFchibi and MoRFchibi-web. The results demonstrate that OPAL outperforms all the available MoRF predictors and is the most accurate predictor available for MoRF prediction. It is available at http://www.alok-ai-lab.com/tools/opal/. ashwini@hgc.jp or alok.sharma@griffith.edu.au. Supplementary data are available at Bioinformatics online.

Retrospective analysis of RF heating measurements of passive medical implants.

Science.gov (United States)

Song, Ting; Xu, Zhiheng; Iacono, Maria Ida; Angelone, Leonardo M; Rajan, Sunder

2018-05-09

The test reports for the RF-induced heating of metallic devices of hundreds of medical implants have been provided to the U.S. Food and Drug Administration as a part of premarket submissions. The main purpose of this study is to perform a retrospective analysis of the RF-induced heating data provided in the reports to analyze the trends and correlate them with implant geometric characteristics. The ASTM-based RF heating test reports from 86 premarket U.S. Food and Drug Administration submissions were reviewed by three U.S. Food and Drug Administration reviewers. From each test report, the dimensions and RF-induced heating values for a given whole-body (WB) specific absorption rate (SAR) and local background (LB) SAR were extracted and analyzed. The data from 56 stents were analyzed as a subset to further understand heating trends and length dependence. For a given WB SAR, the LB/WB SAR ratio varied significantly across the test labs, from 2.3 to 11.3. There was an increasing trend on the temperature change per LB SAR with device length. The maximum heating for stents occurred at lengths of approximately 100 mm at 3 T, and beyond 150 mm at 1.5 T. Differences in the LB/WB SAR ratios across testing labs and various MRI scanners could lead to inconsistent WB SAR labeling. Magnetic resonance (MR) conditional labeling based on WB SAR should be derived from a conservative estimate of global LB/WB ratios. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Exposure Knowledge and Risk Perception of RF EMF

Science.gov (United States)

Freudenstein, Frederik; Wiedemann, Peter M.; Varsier, Nadège

2015-01-01

The presented study is part of the EU-Project Low EMF Exposure Future Networks (LEXNET), which deals among other things with the issue of whether a reduction of the radiofrequency (RF) electro-magnetic fields (EMF) exposure will result in more acceptance of wireless communication networks in the public sphere. We assume that the effects of any reduction of EMF exposure will depend on the subjective link between exposure perception and risk perception (RP). Therefore we evaluated respondents’ RP of different RF EMF sources and their subjective knowledge about various exposure characteristics with regard to their impact on potential health risks. The results show that participants are more concerned about base stations than about all other RF EMF sources. Concerning the subjective exposure knowledge the results suggest that people have a quite appropriate impact model. The question how RF EMF RP is actually affected by the knowledge about the various exposure characteristics was tested in a linear regression analysis. The regression indicates that these features – except distance – do influence people’s general RF EMF RP. In addition, we analyzed the effect of the quality of exposure knowledge on RF EMF RP of various sources. The results show a tendency that better exposure knowledge leads to higher RP, especially for mobile phones. The study provides empirical support for models of the relationships between exposure perception and RP. It is not the aim to extrapolate these findings to the whole population because the samples are not exactly representative for the general public in the participating countries. PMID:25629026

Exposure knowledge and risk perception of RF EMF

Directory of Open Access Journals (Sweden)

Frederik eFreudenstein

2015-01-01

Full Text Available The presented study is part of the EU Project LEXNET (Low EMF Exposure Future Networks, which deals among other things with the issue of whether a reduction of the radiofrequency (RF electro-magnetic fields (EMF exposure will result in more acceptance of wireless communication networks in the public sphere.We assume that the effects of any reduction of EMF exposure will depend on the subjective link between exposure perception and risk perception. Therefore we evaluated respondents’ risk perceptions of different RF EMF sources and their subjective knowledge about various exposure characteristics with regard to their impact on potential health risks. The results show that participants are more concerned about base stations than about all other RF EMF sources. Concerning the subjective exposure knowledge the results suggest that people have a quite appropriate impact model. The question how RF EMF risk perception is actually affected by the knowledge about the various exposure characteristics was tested in a linear regression analysis. The regression indicates that these features - except distance - do influence people’s general RF EMF risk perceptions. In addition, we analyzed the effect of the quality of exposure knowledge on RF EMF risk perception of various sources. The results show a tendency that better exposure knowledge leads to higher risk perception, especially for mobile phones. The study provides empirical support for models of the relationships between exposure perception and risk perception. It is not the aim to extrapolate these findings to the whole population because the samples are not exactly representative for the general public in the participating countries.

Versatile rf controller

International Nuclear Information System (INIS)

Howard, D.

1985-05-01

The low level rf system developed for the new Bevatron local injector provides precise control and regulation of the rf phase and amplitude for three 200 MHz linac cavities. The main features of the system are: extensive use of inexpensive, off-the-shelf components, ease of maintenance, and adaptability to a wide range of operation frequencies. The system utilizes separate function, easily removed rf printed circuit cards interconnected via the edge connectors. Control and monitoring are available both locally and through the computer. This paper will describe these features as well as the few component changes that would be required to adapt the techniques to other operating frequencies. 2 refs

A design and performance analysis tool for superconducting RF systems

International Nuclear Information System (INIS)

Schilcher, T.; Simrock, S.N.; Merminga, L.; Wang, D.X.

1997-01-01

Superconducting rf systems are usually operated with continuous rf power or with rf pulse lengths exceeding 1 ms to maximize the overall wall plug power efficiency. Typical examples are CEBAF at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the TESLA Test Facility at DESY. The long pulses allow for effective application of feedback to stabilize the accelerating field in presence of microphonics, Lorentz force detuning, and fluctuations of the beam current. In this paper the authors describe a set of tools to be used with MATLAB and SIMULINK, which allow to analyze the quality of field regulation for a given design. The tools include models for the cavities, the rf power source, the beam, sources of field perturbations, and the rf feedback system. The rf control relevant electrical and mechanical characteristics of the cavity are described in form of time-varying state space models. The power source is modeled as a current generator and includes saturation characteristics and noise.An arbitrary time structure can be imposed on the beam current to reflect a macro-pulse structure and bunch charge fluctuations. For rf feedback several schemes can be selected: Traditional amplitude and phase control as well as I/Q control. The choices for the feedback controller include analog or digital approaches and various choices of frequency response. Feed forward can be added to further suppress repetitive errors. The results of a performance analysis of the CEBAF and the TESLA Linac rf system using these tools are presented

Performance of the Brookhaven photocathode rf gun

International Nuclear Information System (INIS)

Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Ingold, G.; Kirk, H.G.; Leung, K.P.; Malone, R.; Pogorelsky, I.; Srinivasan-Rao, T.; Rogers, J.; Tsang, T.; Sheehan, J.; Ulc, S.; Woodle, M.; Xie, J.; Zhang, R.S.; Lin, L.Y.; McDonald, K.T.; Russell, D.P.; Hung, C.M.; Wang, X.J.

1991-01-01

The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser-acceleration experiments. The rf gun consists of 1 1/2 cells driven at 2856 MHz in π-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, the photocathode development concentrates on robust metals such as copper, yttrium and samarium. We illuminate these cathodes with a 10-ps, frequency-quadrupled Nd:YAG laser. We describe the initial operation of the gun, including measurements of transverse and longitudinal emittance, quantum efficiencies, and peak current. The results are compared to models

Control electronics of the PEP RF system

International Nuclear Information System (INIS)

Pellegrin, J.L.; Schwarz, H.

1981-01-01

The operation of the major components used for controlling the phase and field level of the PEP RF cavities is described. The control electronics of one RF station is composed of several control loops: each cavity has a tuners' servo loop which maintains the frequency constant and also keeps the fields of each cavity balanced; the total gap voltage developed by a pair of cavities is regulated by a gap voltage controller; finally, the phase variation along the amplification chain, the klystron and the cavities are compensated by a phase lock loop. The design criteria of each loop are set forth and the circuit implementation and test results are presented

Designing focusing solenoids for superconducting RF accelerators

Energy Technology Data Exchange (ETDEWEB)

Davis, G.; Kashikhin, V.V.; Page, T.; Terechkine, I.; Tompkins, J.; Wokas, T.; /Fermilab

2006-08-01

The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of adjacent superconducting RF cavities. The requirement of a compact solenoid, able to fit into a gap between cavities, contradicts the need of mechanical support necessary to restrain electromagnetic forces that can result in coil motion and subsequent quenching. In this report we will attempt to address these and other issues arising during the development of focusing solenoids. Some relevant test data will also be presented.

New achievements in RF cavity manufacturing

International Nuclear Information System (INIS)

Lippmann, G.; Pimiskern, K.; Kaiser, H.

1993-01-01

Dornier has been engaged in development, manufacturing and testing of Cu-, Cu/Nb- and Nb-cavities for many years. Recently, several different types of RF cavities were manufactured. A prototype superconducting (s.c.) B-Factory accelerating cavity (1-cell, 500 MHz) was delivered to Cornell University, Laboratory of Nuclear Studies. A second lot of 6 s.c. cavities (20-cell, 3000 MHz) was fabricated on contract from Technical University of Darmstadt for the S-DALINAC facility. Finally, the first copper RF structures (9-cell, 1300 MHz) for TESLA were finished and delivered to DESY, two s.c. niobium structures of the same design are in production. Highlights from the manufacturing processes of these cavities are described and first performance results will be reported

Simulation experiment on low-level RF control for dual-harmonic acceleration at CSNS RCS

International Nuclear Information System (INIS)

Shen Sirong; Li Xiao; Zhang Chunlin; Sun Hong; Tang Jingyu

2013-01-01

The design and test of the low-level RF (LLRF) control system for the dual-harmonic acceleration at the rapid cycling synchrotron (RCS) of China Spallation Neutron Source (CSNS) at phase Ⅰ is introduced. In order to implement the mode switch from the second harmonic to the fundamental during the acceleration cycle for one of the eight RF cavities, the LLRF system for the cavity has been designed differently from the others. Several technical measures such as the opening of the control loops during the mode switch and the reclosing of two tuning circuits of the RF amplifier at different moments, have been taken. The experimental results on the testing platform based on an RF prototype show good dynamic performance of the LLRF system and prove the feasibility of dual-harmonic operation. (authors)

RF Energy Compressor

International Nuclear Information System (INIS)

Farkas, Z.D.

1980-02-01

The RF Energy Compressor, REC described here, transforms cw rf into periodic pulses using an energy storage cavity, ESC, whose charging is controlled by 180 0 bi-phase modulation, PSK, and external Q switching, βs. Compression efficiency, C/sub e/, of 100% can be approached at any compression factor C/sub f/

Down force calibration stand test report