A5011976299- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Plasma Diagnostics and Applications
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Photocathodes and Microchannel Plates
- Muon and positron interactions and applications
- Nuclear Physics and Applications
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Pulsed Power Technology Applications
- Laser Design and Applications
- Electrostatic Discharge in Electronics
- European history and politics
- Radioactive Decay and Measurement Techniques
- GNSS positioning and interference
- Optical and Acousto-Optic Technologies
- Advanced X-ray Imaging Techniques
- Radio Frequency Integrated Circuit Design
- Radiation Effects in Electronics
- Reformation and Early Modern Christianity
- Public Administration and Political Analysis
- Consumer behavior in food and health
- Distributed Sensor Networks and Detection Algorithms
Los Alamos National Laboratory
1999-2011
Los Alamos National Security (United States)
2006-2007
École Polytechnique Fédérale de Lausanne
2005
Thomas College
2004
University of Arizona
1993
A 110 mA, 75 keV dc proton injector is being developed at Los Alamos. microwave source coupled to a two solenoid, space-charge neutralized, low-energy beam transport (LEBT) system. The ion produces mA current using 600–800 W of 2.45 GHz discharge power. Typical fraction 85%–90% the total extracted current, and rms normalized emittance after through prototype 2.1 m LEBT 0.20 (πmm mrad). Beam neutralization measured be >98% which enables solenoid magnetic successfully match into...
A 75-keV, 130-mA dc mode proton injector is being developed at Los Alamos. The two-solenoid focusing system used in this relies on effective beam space-charge (s.c.) neutralization by ionization of the residual gas. degree s.c. determined measurement energy distribution slow ions created region. non-interceptive gridded-energy analyzer for ion-energy measurement. Application and development diagnostic to a positive hydrogen-ion presented. One feature double-humped distribution. higher...
We report on experimental studies of an ultraviolet (UV) free-electron laser (FEL) oscillator driven by low-energy electrons from a radio-frequency linear accelerator. Previous UV FELs have been 350--800-MeV storage rings. verify the concept driving FEL with low-energy, but high-current, low-emittance electron beam. This and other innovations allowed to lase at wavelengths 369 380 nm using 45.9--45.2-MeV electrons, achieve peak optical output power 270 kW. The results are in good agreement...
A dc and pulsed-mode 75 keV proton injector has been developed is used in characterization of a continuous-wave 6.7 MeV, 100 mA radio-frequency quadrupole (RFQ). The frequently at the full RFQ design power (100 mA, MeV) where admittance (1 rms, normalized) 0.23 (π mm mrad). includes 2.45 GHz microwave source beam space-charge-neutralized, two magnetic-solenoid, low-energy beam-transport system. transmission 95% demonstrated output current.
Employment of H‐ ion sources for the LANSCE accelerator systems goes back about 20 years, to construction Proton Storage Ring (PSR). The standard source consists a filament driven multi‐cusp discharge vessel with biased converter electrode negative‐ion production and an 80‐kV extraction system feeding into 670‐kV electrostatic pre‐accelerator. typically delivers 18 mA pulsed beam current pre‐accelerator column reaches up 35 days between services at 60 Hz pulse repetition rate. Recent...
Recent beam physics studies on the two-stream e-p instability at LANL proton storage ring (PSR) have focused role of electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due grazing angle losses from halo. A new diagnostic measure formation and trapping a magnet has been developed, installed, successfully tested PSR. Beam using this show that ``prompt'' flux striking wall is comparable prompt signal adjacent...
The LANL/AES normal-conducting radio-frequency injector has been tested at cw cathode gradients up to $10\text{ }\text{ }\mathrm{MV}/\mathrm{m}$. Field-emission electrons from a roughened copper are accelerated beam energy as high 2.5 MeV and impinge on stainless steel target. energies of the resulting bremsstrahlung photons measured varying levels cavity rf power corresponding different accelerating gradients. At low power, spectra exhibit well-defined end-point positions where number...
A variety of electron cloud diagnostics have been deployed at the Los Alamos Proton Storage Ring (PSR) to detect, measure, and characterize generated in this high intensity, long bunch accumulator ring. These include a version ANL-developed retarding field analyzers (RFA) augmented with LANL-developed electronics, variant RFA denoted as sweeping diagnostic (ESD), biased collection plates, gas pulse measuring devices. The designs experience performance applicability PSR are discussed.
We have developed a technique for laser tuning at rates of 100 kHz or more using pair acousto-optic modulators. In addition to all-electronic wavelength control, the same modulators also can provide electronically variable Q-switching, cavity length and power stabilization, chirp linewidth output coupling, all far beyond what is possible with conventional mechanically tuned components. Tuning 70 been demonstrated on radio-frequency-pumped CO2 laser, random access over 50 lines spanning 17%...
The electron cloud (EC) at the Los Alamos Proton Storage Ring (PSR) has been studied extensively for past several years with an overall aim to identify and measure its important characteristics, factors that influence these relate two-stream (e-p) transverse instability long observed PSR. Some new results since PAC2001 are presented
Design, manufacturing, and performance of two MMIC low-noise amplifiers are presented in this paper. The circuits cover wide frequency ranges 16-26 GHz 25-49 GHz. implemented using our in-house 0.2 p.m InP HEMT process. measurements at room temperature show a gain higher than 14.5 dB 11 corresponding mean noise 208 K 235 within the K- Q-bands, respectively. Operated 10 K, exhibit 13.5 bands 23-44 GHz,
The Beam Experiments Aboard Rocket (BEAR) accelerator is the major component of an experiment designed to demonstrate operation ion in space and characterize exoatmospheric propagation a neutral particle beam. It produce 10-mA (equivalent), 1-MeV, hydrogen beam 50- mu s pulses at 5 Hz. consists 30-kV, H/sup -/ injector, 1-MeV radiofrequency quadrupole, two 425-MHz RF amplifiers, gas-cell neutralizer, optics, vacuum system, diagnostics, controls. design has been constrained by need for...
A reliable high-voltage (HV) column has been developed for dc proton injectors with applications to high-intensity cw linacs. The HV is coupled a microwave-driven plasma generator produce 75-keV, 110-mA beam. Typical fraction from this source 85%–90%, requiring the and accelerating electrodes operate 130-mA hydrogen-ion beam current. glow-discharge, which was caused by ion axial magnetic field, initially observed in column. This problem solved scaling electron production processes, pressure...
Powerful cw proton linear accelerators (100 mA at 0.5–1.0 GeV) are being proposed for spallation neutron-source applications. A 75-keV, 110-mA dc injector using a microwave ion source is tested these It has achieved 80-keV, hydrogen-ion-beam operation. Video and beam-current toroid diagnostics operational, an EPICS control system also operational on the 75-keV injector. technical base development program been carried out 50-keV obtained from Chalk River Laboratories, it includes low-energy...
The spatial beam density distribution beyond 2.5 to 3 standard deviations of the center is an important property for understanding relatively small fractional losses high intensity beams at Los Alamos Proton Storage Ring (PSR) and transport lines neutron production target. This part (sometimes referred as halo) not well determined by LANSCE-standard wire scanner system nor it yet reliably predicted simulation codes. To significantly improve experimental determination halo, improved has been...
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...