The 11th APPEAL Seminar
APPEAL 11-04
Date and Time: 11:30-12:30 , August 3rd, 2004
Place: Seminar room B, Main building 3F, SPring-8
Speaker: Prof. Alex Bogacz
(Thomas Jefferson National Accelerator Facility, USA.)
Title: Extending the Frontier of Energy Recovery - Ge V Scale Experiment at CEBAF
Abstract: A successful GeV scale energy recovery demonstration with a high ratio of accelerated-to-recovered energies (50:1) was recently carried out on the CEBAF (Continuous Electron Beam Accelerator Facility) recirculating superconducting linear accelerator in an effort to address issues related to beam quality preservation in a large scale energy recovery system. To gain a quantitative understanding of the beam behavior through the machine, an intense effort was made to characterize the 6D phase space during the CEBAF-ER experimental run.
A scheme was implemented to measure the transverse emittance of the energy recovered beam prior to being sent to the dump, as well as in the injector and in each arc. The emittance provides a figure of merit in this context inasmuch as it characterizes the extent to which beam quality is preserved during energy recovery. In addition to describing the transverse phase space, the momentum spread was measured in the injector and arcs to characterize the longitudinal phase space.
Measurements also included the RF systemÅfs response to the energy recovery process. By using a novel technique employing wire scans in conjunction with PMTs (Photomultiplier Tubes) to accurately measure the beam profile at the dump, we can quantify beam losses in the recirculator. One of the salient conclusions from the experiment is that the energy recovery process does not contribute significantly to the emittance degradation since the degradation of the recirculating pass is consistent with that of the accelerating pass.
Contact: Prof. Hiro Ejiri. SPring-8/IIAS/RCNP