CLASSE, Ithaca, New York
Fermilab, Batavia
Cornell University is planning to build an Energy-Recovery Linac (ERL) X-ray facility. In this ERL design, a 5 GeV superconducting linear accelerator extends the CESR ring which is currently used for the Cornell High Energy Synchrotron Source (CHESS). Here we describe some of the recent developments for this ERL, including linear and nonlinear optics, tracking studies, vacuum system design, gas and intra beam scattering computations, and collimator and radiation shielding calculations based on this optics, undulator developments, optimization of X-ray beams by electron beam manipulation, technical design of ERL cavities and cryomodules, and preparation of the accelerator site.
CLASSE, Ithaca, New York
Cornell University, Ithaca, New York
JLAB, Newport News, Virginia
Cornell University has built a high average current electron injector for use with an Energy Recovery Linac. The injector is capable of up to 100 mA average current at 5 MeV (33 mA at 15 MeV) and is expected to produce the ultra low emittances needed for an ERL. This talk will give an overview of the initial performance of this injector and summarize a spectrum of beam physics experiments undertaken to demonstrate low emittance, high average current operation.
CLASSE, Ithaca, New York
Funding: Support provided by the US National Science Foundation and the US Department of Energy.
The Cornell Electron Storage Ring has been reconfigured as a test accelerator (CesrTA) for low emittance damping ring R&D for the International Linear Collider (ILC). We are developing low emittance tuning techniques with a goal of 1) achieving a vertical emittance approaching that of the ILC damping rings and 2) Gaining an understanding of the effectiveness of those techniques. We will use gain mapping to characterize beam position monitor (BPM) electrode gains, orbit response analysis to determine BPM button misalignments, betatron phase and coupling measurements to characterize optical errors, and orbit and dispersion measurements to locate sources of vertical dispersion. We are investigating a nondestructive dispersion measurement that depends on exciting a synchrotron oscillation and monitoring the phase and amplitude at each BPM. We have developed the analysis tools necessary to correct magnet and alignment errors. An x-ray beam size monitor is being deployed that will allow us to monitor vertical emittance in real time, allowing for empirical tuning of beam size. We will describe the measurement and correction techniques and show data demonstrating their efficacy.
CLASSE, Ithaca, New York
This paper describes the results of measurements compared with the analysis of errors for a method of determining accelerator Twiss and coupling parameters from the singular value decomposition of beam position monitor data, taken on a turn-by-turn basis for a storage ring in fully coupled transverse beam coordinates. Using the transversely coupled-coordinate formalism described by Billing et al*, the measurement technique expands on the work of Wang et al**, which describes the SVD of the same data under the assumptions of no transverse coupling of the beam parameters. This particular method of data analysis requires a set of BPM measurements, taken when the beam is resonantly excited in each of its two dipole, betatron normal-modes of oscillation
*M. Billing, et al, to be published in Phys. Rev. S T Accel Beams
**C. Wang, et al, Phys. Rev. S T Accel Beams 6, 104001 (2003)
CLASSE, Ithaca, New York
Commissioning of a new high brightness electron source for the Energy Recovery Linac at Cornell University is currently underway. Despite the fact that the beam dynamics in this portion of the accelerator is space-charge dominated, a fundamental understanding of the machine linear optics is crucial in that it determines the effectiveness of space-charge emittance compensation methods, as well as provides the means to achieving various beam parameters such as beam length and energy spread. Here we introduce a new numerical tool being used in the commissioning of the injector that provides linear optics matrix calculation using field maps for various optical elements.
CLASSE, Ithaca, New York
LBNL, Berkeley, California
KEK, Ibaraki
ANL, Argonne
Fermilab, Batavia
CalPoly, San Luis Obispo, CA
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
SLAC, Menlo Park, California
Cornell University, Ithaca, New York
Cockcroft Institute, Warrington, Cheshire
Funding: Support provided by the US National Science Foundation, the US Department of Energy, and the Japan/US Cooperation Program.
In March of 2008, the Cornell Electron Storage Ring (CESR) concluded twenty eight years of colliding beam operations for the CLEO high energy physics experiment. We have reconfigured CESR as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R&D. The primary goals of the CesrTA program are to achieve a beam emittance approaching that of the ILC Damping Rings with a positron beam, to investigate the interaction of the electron cloud with both low emittance positron and electron beams, to explore methods to suppress the electron cloud, and to develop suitable advanced instrumentation required for these experimental studies (in particular a fast x-ray beam size monitor capable of single pass measurements of individual bunches). We report on progress with the CESR conversion activities, the status and schedule for the experimental program, and the first experimental results that have been obtained.