A5090158825- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear physics research studies
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- High-Energy Particle Collisions Research
- Electron and X-Ray Spectroscopy Techniques
- Integrated Circuits and Semiconductor Failure Analysis
- Photocathodes and Microchannel Plates
- Plasma Diagnostics and Applications
- Radiation Effects in Electronics
- Quantum Chromodynamics and Particle Interactions
- Radiation Therapy and Dosimetry
- Advanced Chemical Physics Studies
- Silicon Carbide Semiconductor Technologies
- Radiation Detection and Scintillator Technologies
- Mass Spectrometry Techniques and Applications
- Laser-Plasma Interactions and Diagnostics
- Electrostatic Discharge in Electronics
Brookhaven National Laboratory
2014-2023
Cornell University
2018
Brookhaven College
2014
RIKEN BNL Research Center
1984-2007
Associated Universities, Inc.
1990-2003
Stanford University
1987-1993
Lawrence Berkeley National Laboratory
1993
Maulana Azad National Institute of Technology
1990
Comisión Nacional de Energía Atómica
1979-1986
Michigan State University
1986
Cross sections for the electron capture by 82- , 140- and 200-MeV/amu ${\mathrm{Xe}}^{54+}$, ${\mathrm{Xe}}^{53+}$, ${\mathrm{Xe}}^{52+}$ ions incident on thin solid targets from Be to Au were measured. The measurements are compared with calculations of radiative nonradiative capture. based relativistic eikonal approximation which includes transitions K, L, M shells target nearly all projectile shells. In high-Z targets, into excited states is dominant, as predicted confirmed comparing...
The behavior of the moment inertia for high-spin states in ${\mathrm{Dy}}^{158}$ has been studied by populating ground-state band up to spin 22 through reaction ${\mathrm{Nd}}^{150}({\mathrm{C}}^{13}, 5N){\mathrm{Dy}}^{158}$ at bombarding energies 72 MeV. rate increase $\mathcal{I}$ with rotational frequency rises abruptly region from 14 18. In 22, tends toward a more constant value.
Charge-state distributions were measured for incident 105-, 220-, 430-, and 955-MeV/amu U ions on thin thick solid targets. Initial bare, one-, two-, three-, nine-, 24-electron used, so that single multiple ionization of K-, L-, M-shell electrons electron capture into bare having initially full or partially K L shells could be observed. Multiple-ionization effects in two-electron many the K, L, M are calculated by using semiclassical approximation assuming binomial statistics. Binding...
High-spin three-particle levels populated in the decay of a 182\ifmmode\pm\else\textpm\fi{}6-\ensuremath{\mu}sec isomeric state $^{207}\mathrm{Bi}$ have been studied using pulsed external beam Stockholm 225-cm cyclotron. The was produced $^{205}\mathrm{T}1(28\ensuremath{-}\mathrm{MeV} \ensuremath{\alpha}, 2n)^{207}\mathrm{Bi}$ reaction. intensities and energies 13 delayed $\ensuremath{\gamma}$ transitions observed fit consistently into level scheme six excited having (keV) spins: 2101.5...
Projectile 1s ionization cross sections are reported for 82- , 140- and 200-MeV/amu Xe projectiles incident on a variety of thin solid targets between Be Au. The were calculated with the plane-wave Born approximation. Possible relativistic wave-function, target-screening, transverse-excitation effects discussed. Comparisons data perturbed-stationary-state theory Basbas et al. Glauber approximation made. Scaled, interpolated Xe+Xe agree well measured p+H sections.
Since 2001, the Relativistic Heavy Ion Collider has experienced electron cloud effects, some of which have limited beam intensity. These include dynamic pressure rises (including instabilities), tune shifts, a reduction instability threshold for bunches crossing transition energy, and possibly incoherent emittance growth. We summarize main observations in operation dedicated experiments as well countermeasures including baking, nonevaporable getter coated warm pipes, solenoids, bunch...
Cooling of beams gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens possibility this technique higher energies than possible electrostatic acceleration beams. The challenges include generation suitable for cooling, delivery required quality to cooling sections without degradation beam angular divergence energy spread,...
During space travel, astronauts are exposed to cosmic radiation that is comprised of high-energy nuclear particles. Cancer patients also particles when treated with proton and carbon beams. Nuclear interactions from traversing shielding materials tissue produce low-energy (<10 MeV/n) secondary high-LET contribute significantly overall exposures. Track structure theories suggest high charge energy (HZE) ions similar LET will have distinct biological effects for cellular damage endpoints. We...
Time distributions of resonantly scattered 14.4-keV ${\mathrm{Fe}}^{57}$ $\ensuremath{\gamma}$ rays were measured by using as time-zero signals the preceding 122-keV rays. A ${\mathrm{Co}}^{57}$ source coplated with Fe was used two different metallic scatterers (2.54\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}2}$-mm-thick 92.8% and 4.53\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}3}$-mm-thick 2.19% ${\mathrm{Fe}}^{57}$) in a cylindrical geometry. Measurements performed...
In ion-atom collisions where the projectile is ionized, target electrons act not only coherently by screening nucleus but they may also incoherently directly ejecting a electron. This electron-electron interaction should be relatively most important for targets that have low nuclear charge, since cross section neutral roughly proportional to ${\mathit{Z}}_{\mathit{t}}^{2}$+${\mathit{Z}}_{\mathit{t}}$, ${\mathit{Z}}_{\mathit{t}}^{2}$ contribution due and ${\mathit{Z}}_{\mathit{t}}$ comes from...
Head-on beam-beam compensation has been implemented in the Relativistic Heavy Ion Collider order to increase luminosity delivered experiments. We discuss principle of combining a lattice for resonance driving term and an electron lens tune spread compensation. describe technology its operational use. To date, scheme approximately doubled peak average luminosities.
Rotational bands in the odd-odd nucleus $^{180}\mathrm{Re}$ have been studied via $^{176}\mathrm{Yb}$${(}^{10}$B,6n) and $^{181}\mathrm{Ta}$(\ensuremath{\alpha},5n) fusion-evaporation reactions. A completely new high-spin level scheme has obtained comprising four \ensuremath{\Delta}I=1 a \ensuremath{\Delta}I=2 band. The structures can be understood from quasiparticle states neighboring odd nuclei band is interpreted as example of double decoupled sequence based on ${h}_{9/2}$ proton...
Secondary-electron yields were investigated for 28-MeV protons, 126-MeV oxygen-ions, and 182-MeV gold ions incident on 304 stainless-steel surfaces. The dependence the incidence angle was studied in detail, a system developed which allows accurate measurements to be performed over wide angular range extending nearly grazing collisions. Electron yield estimates of interest future accelerator applications are 1-GeV possible mitigation deleterious effects by using serrated rather than flat...
States of $^{200}\mathrm{Tl}$, populated through the $^{198}\mathrm{Pt}(^{6}\mathrm{Li},4n)$ reaction at $E=30 \mathrm{to} 40$ MeV, were studied using in-beam $\ensuremath{\gamma}$-ray spectroscopy techniques. An almost completely new level scheme is presented comprising $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\pi}}{h}_{\frac{9}{2}}\ensuremath{\bigotimes}\stackrel{\ifmmode \~{}\fi{}}{\ensuremath{\nu}}{i}_{\frac{13}{2}}$ two-quasiparticle band which in this case built on an...
A heavy ion beam diagnostic system installed at the Brookhaven Single Event Upset Test Facility is described. Calibration of with help a-particles, essential for linear energy transfer (LET) measurements, discussed. Measured LET values 20 different ions, including /sup 7/Li, 9/B, 12/C, 16/O, 19/F, 28/Si, 32/S, 35/Cl, 40/Ca, 45/Sc, 48/Ti, 56/Fe, 58/Ni, 63/Cu, 74/Ge, 79/Br, 107/Ag, 127/I, 197/Au, and 235/U, energies between 0.5 8.5 MeV/AMU but not exceeding 400 MeV heaviest are presented in...
Rotational bands in the odd-odd nucleus $^{182}\mathrm{Ir}$ and odd-mass isotopes $^{181,183}\mathrm{Ir}$ have been studied via fusion-evaporation reactions $^{172,174}\mathrm{Yb}$${(}^{14}$N,xn) utilizing \ensuremath{\gamma}-ray spectroscopy techniques. The different band structures are interpreted as specific couplings of proton neutron single-quasiparticles present neighboring odd Ir Os Pt nuclei.
Single-Event Upset (SEU) response of a bipolar low-power Schottky-diode-clamped TTL static RAM has been observed using Br ions in the 100-240 MeV energy range and 0 20-100 range. These data complete experimental verification circuit-simulation SEU modeling for this device. The threshold onset by variation energy, ion species angle incidence. results obtained from computer model demonstrate viable methodology integrated circuits.