A5027078072- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Laser Design and Applications
- Plasma Diagnostics and Applications
- Atomic and Subatomic Physics Research
- Laser-Matter Interactions and Applications
- Laser-Plasma Interactions and Diagnostics
- Solid State Laser Technologies
- Advanced Photonic Communication Systems
- Particle Detector Development and Performance
- Advanced MEMS and NEMS Technologies
- Microwave and Dielectric Measurement Techniques
- Power Line Communications and Noise
- Antenna Design and Analysis
- Telecommunications and Broadcasting Technologies
- Pulsed Power Technology Applications
- Digital Filter Design and Implementation
- Spacecraft and Cryogenic Technologies
- Advanced Measurement and Metrology Techniques
- Radiation Therapy and Dosimetry
- Advanced Adaptive Filtering Techniques
University of Wisconsin–Madison
1996-2023
Oak Ridge National Laboratory
2006-2020
Fermi Research Alliance
2002
Fermi National Accelerator Laboratory
1999-2001
University of Wisconsin System
1999
Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping become radioactive and produce uncontrolled beam loss, which is one of main factors limiting power in Recently, we presented a scheme laser an ${\mathrm{H}}^{\ensuremath{-}}$ Spallation Neutron Source (SNS) ring. First, atoms converted to ${\mathrm{H}}^{0}$ by magnetic field, then excited from ground state upper levels laser, states protons field. In this paper...
We demonstrate a master oscillator power amplifier (MOPA) burst mode laser system that generates 66 ps/402.5 MHz pulses with mega-watt peak at 355 nm. The seed consists of single frequency fiber (linewidth < 5 KHz), high bandwidth electro-optic modulator (EOM), picosecond pulse generator, and based preamplifier. A very extinction ratio (45 dB) has been achieved by using an adaptive bias control the EOM. multi-stage Nd:YAG allows uniformly temporal shaping macropulse tunable duration. light...
The paper reports on latest developments for the ITER Ion Cyclotron Heating and Current Drive system: imminent acceptance tests of a prototype power supply at full power; successful factory candidate RF amplifier tubes which will be tested dedicated facilities; further design integration experimental validation transmission line components under 6MW hour-long pulses. antenna Faraday shield thermal has been validated above requirements by cyclic high heat flux tests. R&D ceramic brazing is...
The ITER Ion Cyclotron Heating and Current Drive system (IC H&CD) is designed to deliver 20MW a broad range of plasma scenarios between 40 55MHz, during very long pulses. It consists two broadband equatorial port plug antennas, their pre-matching matching systems, transmission lines, Radio Frequency (RF) Sources High Voltage Power Supplies. overall project schedule has been revised agreed by Council; it re-integrates the second antenna its power supplies in construction baseline sets dates...
To assist the beam commissioning in Spallation Neutron Source (SNS) linac, a general purpose Radio Frequency (RF) tuning application has been written to help set RF phase and amplitude. The method involves varying an Rf cavity amplitude settings over fairly large range comparing measured downstream response "signatures" model predictions. input for phase, amplitude, energy are varied best match observations. This scheme advantages other techniques of not requiring intercepting devices (e.g....
The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to liquid mercury target for neutron scattering research. complex consists of an H-injector, capable producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, 1 GeV linear accelerator, accumulator ring and associated transport lines. 2.5 MeV from the Front End is accelerated 86 in Drift Tube Linac, then 185 Coupled-Cavity Linac finally Superconducting Linac. With completion...
After a successful demonstration of nonintercepting beam profile monitor for the H/sup -/ beams at 750 KeV and 200 MeV LINAC Brookhaven National Laboratory, SNS project approved using Nd:YAG laser rather than traditional carbon wire transverse monitors in superconducting LINAC. Experiments have also been performed on 2.5 medium energy transport line LBNL. The design implementation multistation monitoring system single will be presented. is scanned across to photoneutralize narrow slices....
Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping become radioactive and produce uncontrolled beam loss, which is one of main factors limiting power in Recently, we presented a scheme laser an H <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> Spallation Neutron Source ring. First, atoms converted to xmlns:xlink="http://www.w3.org/1999/xlink">0</sup> by magnetic...
The pulsed beam in the SNS accelerator has a fine time structure which consists of 695 ns long mini-pulses separated by 250 gaps order to minimize transient losses accumulator ring could arise during extraction kicker rise time. This is provided two stage Front End chopping system must reduce current gap level 10/sup -4/ nominal satisfy requirements on losses. A Beam-in-Gap measuring based H/sup -/ stripping using Nd-YAG laser was developed and tested Front-End commissioning period. paper...
The Spallation Neutron Source being built at Oak Ridge National Laboratory employs eighty one 805 MHz superconducting cavities operated 2.1 K to accelerate the H-beam from 187 MeV about 1 GeV. and cryomodules with two different values of beta (. 61 .81) have been designed constructed Jefferson Lab for operation unloaded Q's in excess 5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> . To gain experience testing SNS tunnel before final...
A prototype of an analog, transverse (vertical) feedback system for active damping the two-stream (e-p) instability has been developed and successfully tested at Los Alamos Proton Storage Ring (PSR). This was able to improve threshold by approximately 30% (as measured change in RF buncher voltage threshold). The configuration, setup procedures, optimization performance are described. Results several experimental tests presented including observations improvement grow-damp experiments, which...
A prototype of an analog, transverse feedback system for damping the two-stream (e-p) instability has been developed and successfully tested at Los Alamos Proton Storage Ring (PSR). This paper describes configuration, results several experimental tests studies optimization along with factors limiting its performance.
The chopper system for the spallation neutron source (SNS) provides a gap in beam clean extraction from accumulator ring. It consists of pre-chopper low energy transport and faster medium (MEBT). original "meander line" design MEBT deflector was successfully tested with power during SNS linac commissioning but turned out to be unsuitable high operation due poor cooling copper strip line through dielectric substrate. We developed new deflecting structure, higher deflection efficiency rise...