A5069705279- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Gyrotron and Vacuum Electronics Research
- Particle Detector Development and Performance
- Plasma Diagnostics and Applications
- Photocathodes and Microchannel Plates
- Advanced X-ray Imaging Techniques
- Physics of Superconductivity and Magnetism
- Electron and X-Ray Spectroscopy Techniques
- Particle physics theoretical and experimental studies
- Radiation Therapy and Dosimetry
- Laser-Plasma Interactions and Diagnostics
- Silicon Carbide Semiconductor Technologies
- Spacecraft and Cryogenic Technologies
- Advancements in Photolithography Techniques
- Atomic and Molecular Physics
- Pulsed Power Technology Applications
- Atomic and Subatomic Physics Research
- Advanced Electron Microscopy Techniques and Applications
- Medical Imaging Techniques and Applications
- Electromagnetic Simulation and Numerical Methods
- Advanced Frequency and Time Standards
- Superconductivity in MgB2 and Alloys
Cornell University
2015-2025
Brookhaven National Laboratory
2017-2023
SLAC National Accelerator Laboratory
2022
Menlo School
2022
Fermi Research Alliance
2015
John Brown University
2008
Ithaca College
2007
Institute of Particle Physics
2006
Deutsches Elektronen-Synchrotron DESY
2000
Technical University of Darmstadt
1999
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...
The superconducting RF linac for Linac Coherent Light Source-II calls 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7 × 1010 at 2.0 K and 16 MV/m accelerating gradient. Two niobium 9 cell cavities, prepared nitrogen-doping Fermilab, were assembled into the Cornell Horizontal Test Cryomodule (HTC) to test cavity performance in a cryomodule that is very similar full LCLS-II cryomodule. met specifications quench field 17 3 1010. sensitivity cavities' residual...
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...
We present a new method for minimizing the effects of radiative depolarization in electron storage rings by use minimal number special vertical orbit bumps. The bumps can be used to minimize while simultaneously maintaining other common benefits orbits, e.g., transverse coupling and dispersion control. Because optimizing large correctors ring is operationally infeasible, we dimensionality reduction define most effective groups that optimized during operation, motivating name “Best Adjustment...
Here we will derive the general theory of beam-breakup instability in recirculating linear accelerators, which bunches do not have to be at same rf phase during each recirculation turn. This is important for description energy recovery linacs where are recirculated a decelerating wave and other recirculator arrangements different phases an advantage. Furthermore it can used analysis errors bunches. It shown how threshold current given linac computed remarkable agreement with tracking data...
Coherent synchrotron radiation has been studied effectively using a one-dimensional model for the charge distribution in realm of small angle approximations and high energies. Here we use Jefimenko's form Maxwell's equations, without such approximations, to calculate exact wakefields due this effect multiple bends drifts. It shown before that influence drift can propagate well into subsequent bend. We show, reasonable parameters, previous bend also bend, is especially important at beginning...
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...
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...
In recirculating accelerators, and, in particular, energy-recovery linacs, the maximum current can be limited by multipass, multibunch beam breakup (BBU), which occurs when electron interacts with higher-order modes (HOMs) of an accelerating cavity on pass and again energy recovering pass. This effect is particular concern design modern high average accelerators utilizing superconducting rf technology. Experimental characterization observations instability at Jefferson Laboratory 10 kW free...
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...
Quasimonochromatic x rays are difficult to produce above 100 keV, but have a number of uses in x-ray and nuclear science, particularly the analysis transuranic species. Inverse Compton scattering (ICS) is capable fulfilling this need, producing photon beams with properties energies well beyond limits typical synchrotron radiation facilities. We present design predicted output such an ICS source at CBETA, multiturn energy-recovery linac top energy 150 MeV, which we anticipate 400 keV...
Here we will derive the general theory of beam-breakup (BBU) instability in recirculating linear accelerators with coupled beam optics and polarized higher-order dipole modes. The bunches do not have to be at same radio-frequency phase during each recirculation turn. This is important for description energy recovery linacs (ERLs) where currents become very large are used on purpose increase threshold current. can analysis errors recirculated bunches, optical coupling arrangement. It shown...
One of the main concerns in design low emittance linear accelerators (linacs) is preservation beam emittance. Here we discuss one possible source dilution, coupler kick, due to transverse electromagnetic fields accelerating cavities linac caused by power geometry. In addition growth, kick also produces orbit distortions. It common wisdom that growth from kicks can be strongly reduced using two couplers per cavity mounted opposite each other or having successive alternate above below pipe so...
So far, polarized proton beams have never been accelerated to energies higher than 25 GeV. During the acceleration process, beam polarization is quite undisturbed, when accelerator well adjusted, except at first-order depolarizing spin orbit resonances. At some accelerators other effects observed but resonances always dominant. these tune plus or minus one of tunes an integer. These usually investigated by theories which correspondingly lead undisturbed during acceleration, such Therefore we...
We present an improved system for orbit and betatron phase measurement utilizing nonlinear models of BPM pickup response. first describe the calculation signals as functions beam position using Green's reciprocity theorem with a two-dimensional formalism. then incorporation these calculations in our measurements by inverting functions, giving us function signals, how this is also used to improve advance. Measurements are presented comparing linearized response historically at CESR.
Energy recovery linacs provide high-energy beams, but decelerate those beams before dumping them, so that their energy is available for the acceleration of new particles. During this deceleration, any relative spread created at high amplified by ratio between and dump energy. Therefore, are sensitive to acquired energy, e.g., from wakefields. One can compensate time-correlated due wakes via energy-dependent time-of-flight terms in appropriate sections an linac, high-frequency cavities. We...
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)....
When polarized particles are accelerated in a synchrotron, the spin precession can be periodically driven by Fourier components of electromagnetic fields through which travel. This leads to resonant perturbations when spin-precession frequency is close linear combination orbital frequencies. such resonance conditions crossed, partial depolarization or flip occur. The amount polarization that survives after crossing function strength and speed. commonly called Froissart-Stora formula. It very...
We describe the status of plans to build an Energy-Recovery Linac (ERL) X-ray facility at Cornell University. This 5 GeV ERL is upgrade CESR ring that currently powers High Energy Synchrotron Source (CHESS) [1]. Due its very small electron-beam emittances, it would dramatically improve capabilities light source and result in beams orders magnitude better than any existing storage-ring source. The emittances are based upon simulations for currents competitive with ring-based sources [2, 4]....