A5078944954- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Magnetic confinement fusion research
- Advanced X-ray Imaging Techniques
- Gyrotron and Vacuum Electronics Research
- Photocathodes and Microchannel Plates
- Atomic and Subatomic Physics Research
- Muon and positron interactions and applications
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Electron and X-Ray Spectroscopy Techniques
- Plasma Diagnostics and Applications
- Distributed and Parallel Computing Systems
- Quantum, superfluid, helium dynamics
- Diamond and Carbon-based Materials Research
- X-ray Spectroscopy and Fluorescence Analysis
- Vacuum and Plasma Arcs
- Cold Atom Physics and Bose-Einstein Condensates
- Radiation Detection and Scintillator Technologies
- Radiation Therapy and Dosimetry
- Fusion materials and technologies
- Advancements in Photolithography Techniques
- Particle physics theoretical and experimental studies
Cornell University
2014-2024
Thomas Jefferson National Accelerator Facility
2021
Brookhaven National Laboratory
2018
St. Mary's College of Maryland
2016
University of Connecticut
2016
University of Liverpool
2011
Wayne State University
1998
Measurements of the pressure and magnetic field dependence ${A}_{1}$ ${A}_{2}$ transitions in superfluid $^{3}\mathrm{He}$ are reported. The ${A}_{1}\ensuremath{-}{A}_{2}$ splitting, ${T}_{{A}_{1}}\ensuremath{-}{T}_{{A}_{2}}$, is nearly a linear function over range 0-9.4 T. For given field, observed increase ${T}_{{A}_{1}}\ensuremath{-}{T}_{c}$ with increasing accordance recent theory by Bedell Quader.
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...
A formalism for describing the coupled two-dimensional motion of high energy particle beams in a storage ring is developed and extended to circumstances where coupling very strong, such as M\"obius twist accelerator.
Measurement of the betatron phase in vertical and horizontal planes as well transverse horizontal-vertical coupling is a standard procedure now used at Cornell Electron/Positron Storage Ring. The measurement made by shaking beam observing oscillation detectors located around ring. measurements allow quadrupolar errors to be corrected.
Coherent synchrotron radiation can severely limit the performance of accelerators designed for high brightness and short bunch length. Examples include light sources based on energy recovery LINAC or free-electron lasers, compressors linear colliders. In order to better simulate coherent radiation, a one-dimensional formalism due Saldin, Schneidmiller, Yurkov has been implemented in general beam dynamics code Bmad. Wide vacuum chambers are simulated by means vertical image charges. Results...
Intrabeam scattering (IBS) limits the emittance and single-bunch current that can be achieved in electron or positron storage ring colliders, damping rings, light sources. Much theoretical work on IBS exists, while theories have been validated hadron ion machines, presence of strong makes lepton machines a different phenomenon. We present results measurements at CesrTA IBS-dominated beams, compare data with theory. The beams we study parameters typical those specified for next generation...
In 2008 the Cornell Electron/Positron Storage Ring (CESR) was reconfigured from an electron/positron collider to serve as a testbed for International Linear Collider (ILC) damping rings. One of primary goals CESR Test Accelerator (CesrTA) project is develop fast low-emittance tuning method which scales well large rings such ILC rings, and routinely achieves vertical emittance order 10 pm at 2.085 GeV. This paper discusses methods developed CesrTA achieve conditions. iteration beam-based...
Landau damping—the damping of coherent oscillations in a system oscillators with feedback—has been observed many diverse systems from plasmas to quarks the flashing fireflies. There are two general approaches that have used understand damping: One approach analyzes terms dephasing oscillators. Another explains as result an energy drain those resonant oscillation. Both studied this paper and it is shown while may seem different, they both valid descriptions damping.
The first stage of the FCC (Future Circular Collider) is a high-luminosity electron-positron collider (FCC-ee) with centre-of-mass energy ranging from 88 to 365 GeV, study high precision Z, W, Higgs and top particles, samples $5 \times 10^{12}$ Z bosons, $10^8$ W pairs, $10^6$ bosons quark pairs. A cornerstone physics program lays in precise (ppm) measurements masses widths, as well forward-backward asymmetries. To this effect distribution should be determined precision. This document...
Synchrotron light sources based on Energy Recovery Linacs (ERLs) show promise to deliver X-ray beams with both brilliance and pulse duration far superior the values that can be achieved storage ring technology. Cornell University, in collaboration Jefferson Laboratory, has proposed construction of a prototype ERL. This 100MeV, 100mA CW superconducting electron accelerator will used study resolve many physics technology issues this type machine. These studies are essential before ERLs...
As part of the Bmad software library, a program called Synrad3D has been written to track synchrotron radiation photons generated in storage rings. The purpose is primarily estimate intensity and distribution photon absorption sites, which are critical inputs codes model growth electron clouds. includes scattering from vacuum chamber walls using X-ray data an LBNL database. can handle any planar lattice wide variety profiles.
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...
Beam-beam interactions pose substantial challenges in the design and operation of circular colliders, significantly affecting their performance. In particular, weak-strong simulation approach is pivotal for investigating single-particle dynamics during collider phase. This paper evaluates limitations existing models simulations, noting that while they accurately account energy changes due to slingshot effects, fail incorporate longitudinal coordinate (<a:math...
The coherent interaction between the electron beam and trapped ions in Cornell Electron/positron Storage Ring (CESR) has been seen by shaking observing resulting oscillation amplitude. A linear theory is developed which enables calculation of ion densities from experimental measurements. Nonlinearities beam-ion force are shown to be important understanding trapping effects including frequency shifts betatron sideband resonances.
Low emittance tuning at the Cornell Electron Storage Ring (CESR) test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs) consist four button electrodes, instrumented with electronics that allow acquisition turn-by-turn data. response to will vary among electrodes due differences in electronic gain and/or misalignment. This variation BPM couple real horizontal offset apparent position, introduce spurious...
In storage rings, horizontal dispersion in the rf cavities introduces horizontal-longitudinal (xz) coupling, contributing to beam tilt xz plane. This coupling can be characterized by a "crabbing" term {\zeta}a that appears normal mode decomposition of 1-turn transfer matrix. is proportional cavity voltage and cavity. We report experiments at Cornell Electron Storage Ring Test Accelerator (CesrTA) where was explored using three lattices with distinct crabbing properties. characterize for each...
The ever increasing demands placed upon machine performance have resulted in the need for more comprehensive particle accelerator modeling. Computer simulations are key to success of accelerators. Many aspects accelerators rely on computer modeling at some point, sometimes requiring complex simulation tools and massively parallel supercomputing. Examples include beams extreme intensities densities (toward quantum degeneracy limit), with ultra-fine control (down level individual particles)....
The trapping of dust particles with an attendant reduction in beam lifetime and/or increased radiation rates is aperiodically observed the Cornell Electron/positron Storage Ring CESR. A measurement stability trapped as a function bunch current single electrons confirmed directly that are heavier than any normal constituent residual gas vacuum chamber. removal individual from via image charge forces were and change together at which left permitted calculation mass charge. surface electric...
We present a detailed design for operation of the Cornell Electron Storage Ring, CESR, in energy range covering /spl psi/ resonances and Charm Tau thresholds, as well reaching to upper Y near 11 GeV. The addition 18 m super-ferric wiggler magnets will partially restore low beam emittance damping times. Installation superconducting quadrupoles interaction region high performance RF cavities enhance at all energies. Studies optics, dynamics, vacuum system performance, stability, beam-beam...
Recent interest in applications of wiggler magnets storage rings has motivated efforts to incorporate their effects calculations beam dynamics. This paper presents an analytic model fields that can be used with symplectic integration evaluate such effects. Coefficients needed by the are generated fitting results a finite-element field calculation. The been successfully CESR-c project, which imposes tolerances few parts 10/sup 4/ on modeling 2-Tesla superconducting wigglers. In contrast...