A5001641030- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- Superconducting Materials and Applications
- Photocathodes and Microchannel Plates
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- Gyrotron and Vacuum Electronics Research
- Plasma Diagnostics and Applications
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Magnetic confinement fusion research
- Ion-surface interactions and analysis
- Electron and X-Ray Spectroscopy Techniques
- Nuclear Physics and Applications
- Pulsed Power Technology Applications
- CCD and CMOS Imaging Sensors
- Photonic and Optical Devices
- Atomic and Molecular Physics
- X-ray Spectroscopy and Fluorescence Analysis
- Spacecraft and Cryogenic Technologies
- Advanced Electron Microscopy Techniques and Applications
- Calibration and Measurement Techniques
- Graphite, nuclear technology, radiation studies
Cornell University
2011-2021
Brookhaven National Laboratory
2018-2019
Max Planck Institute for Physics
1982-1985
Max Planck Institute for Astrophysics
1985
Columbia University
1980-1982
Stony Brook University
1981
State University of New York
1981
High-power, high-brightness electron beams are of interest for many applications, especially as drivers free lasers and energy recovery linac light sources. For these particular photoemission injectors used in most cases, the initial beam brightness from injector sets a limit on quality generated at end accelerator. At Cornell University, we have built such high-power using DC gun followed by superconducting accelerating module. Recent results will be presented demonstrating record setting...
During an energy scan at the Cornell Electron Storage Ring, with use of Columbia University-Stony Brook NaI detector, enhancement in $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons})$ is observed center-of-mass \ensuremath{\sim}10.55 GeV. The mass and leptonic width this state (${\ensuremath{\Upsilon}}^{\ensuremath{'}\ensuremath{'}\ensuremath{'}}$) suggest that it $4^{3}S_{1}$ bound $b$ quark its antiquark. After applying to data a cut (pseudo) thrust...
The $\ensuremath{\Upsilon}$, ${\ensuremath{\Upsilon}}^{\ensuremath{'}}$, and ${\ensuremath{\Upsilon}}^{\ensuremath{'}\ensuremath{'}}$ states have been observed at the Cornell Electron Storage Ring as narrow peaks in $\ensuremath{\sigma}({e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons})$ versus beam energy. Data were collected during a run with integrated luminosity of 1000 ${\mathrm{nb}}^{\ensuremath{-}1}$, using Columbia University-Stony Brook segmented NaI detector....
We present a detailed study of the six-dimensional phase space electron beam produced by Cornell Energy Recovery Linac Photoinjector, high-brightness, high repetition rate (1.3 GHz) DC photoemission source designed to drive hard x-ray energy recovery linac (ERL). A complete simulation model injector has been constructed, verified measurement, and optimized. Both horizontal vertical 2D transverse spaces, as well time-resolved (sliced) space, were simulated directly measured at end for 19 77...
Energy recovery has been achieved in a multipass linear accelerator, demonstrating technology for more compact particle accelerators operating at higher currents and reduced energy consumption. delivered to the beam during first four passes through accelerating structure was recovered subsequent decelerating passes. High-energy efficiency by use of superconducting cavities permanent magnets. The fixed-field alternating-gradient optical system used return loop successfully transported...
The Cornell University energy recovery linac (ERL) photoinjector has recently demonstrated operation at 20 mA for approximately 8 hours, utilizing a multialkali photocathode deposited on Si substrate. We describe the recipe deposition, and will detail parameters of run. Post-run analysis indicates presence significant damage to substrate, perhaps due ion back-bombardment from residual beam line gas. While exact cause substrate remains unknown, we multiple surface characterization techniques...
In a sample of 10 000 ${\ensuremath{\Upsilon}}^{\ensuremath{'}}$ decays observed with our nonmagnetic detector at the Cornell Electron Storage Ring, we find 23 events consistent decay ${\ensuremath{\Upsilon}}^{\ensuremath{'}}\ensuremath{\rightarrow}\ensuremath{\Upsilon}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. We derive branching fraction...
Using the Colubia University---Stony Brook detector we have measured production of energetic electrons ($E>1$ GeV) in ${e}^{+}{e}^{\ensuremath{-}}$ annihilations center-of-mass energy range 10.4 to 11.4 GeV. We observe an enhanced electron signal at ${\ensuremath{\Upsilon}}^{\ensuremath{'}\ensuremath{'}\ensuremath{'}}(4S)$ resonance, which interpret as evidence for $\ensuremath{\beta}$ decay a new flavor quark, $b$, bound within meson, $B$. derive branching ratio...
A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe gun's overall mechanical design, surface preparation of components, as well clean construction methods. We present conditioning data using 50 mm gap, in exceeds 500 kV, smaller gaps. Finally, simulated emittance results obtained from genetic optimization scheme values based on data....
The superconducting cavities in an Energy-Recovery-Linac will be operated with a high loaded Q of several 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> , possible up to xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> . Not only has no prior control system ever stabilized the RF field elliptical linac cavity such Q, but also highest stability amplitude and phase is required at this Q. Because resulting bandwidth few Hz, presents...
This design report describes the construction plans for world's first multi-pass SRF ERL. It is a 4-pass recirculating linac that recovers beam's energy by 4 additional, decelerating passes. All beams are returned deceleration in single beam pipe with large-momentum-aperture permanent magnet FFAG optics. Cornell University has been pioneering new class of accelerators, Energy Recovery Linacs (ERLs), characteristic set parameters. Technology prototyped essential any high brightness electron...
Cornell University has prototyped technology essential for any high brightness electron ERL. This includes a DC gun and an SRF injector Linac with world-record current normalized in bunch train, high-current CW cryomodule, high-power beam stop, several diagnostics tools high-brightness beams, e.g. slid measurements 6-D phase-space densities, fast wire scanner profiles, loos diagnostics. All these are now available to equip one-cryomodule ERL, laboratory space been cleared out is radiation...
We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses simple planetary gear setup to rotate wire, fixed at one end, through the speeds excess of $20\text{ }\text{ }\mathrm{m}/\mathrm{s}$. present results from bench tests, as well transverse profile measurements taken Cornell's high-brightness energy recovery linac photoinjector, up 35 mA.
We have recently performed experiments to test the effectiveness of three ion-clearing strategies in Cornell high intensity photoinjector: DC clearing electrodes, bunch gaps, and beam shaking. The photoinjector reaches a new regime linac parameters where continuous wave currents lead ion trapping. Therefore mitigation must be evaluated for this machine other similar future current linacs. developed several techniques directly measure residual trapped ions. Our two primary indicators...
The Cornell-BNL FFAG-ERL Test Accelerator (C$β$) will comprise the first ever Energy Recovery Linac (ERL) based on a Fixed Field Alternating Gradient (FFAG) lattice. In particular, we plan to use Non Scaling FFAG (NS-FFAG) lattice that is very compact and thus space- cost- effective, enabling multiple passes of electron beam in single recirculation line, using superconducting RF (SRF) linac times. moves cost optimized dramatically better optimum. prime accelerator science motivation for C$β$...
We report on the design and prototype studies for a new double-sided silicon vertex detector CLEO-II experiment at CESR. To minimize multiple scattering, two techniques are employed: (1) is supported by low mass, Z boron carbide foam U-channels; (2) preamplifiers removed entirely from tracking volume using second layer of metallization to provide longitudinal readout traces transverse sense strips.