Author: Ruan, J.
Paper Title Page
MOP021 Commissioning of a Dual-sweep Streak Camera with Applications to the ASTA Photoinjector Drive Laser 66
  • A.H. Lumpkin, D.R. Edstrom, J. Ruan, J.K. Santucci
    Fermilab, Batavia, Illinois, USA
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The high-power electron beams for the Advanced Superconducting Test Accelerator (ASTA) facility will be generated in a photoinjector based on a UV drive laser and the L-band rf photocathode (PC) gun cavity. The initial objectives of these studies were: 1) the evaluation of the amplified UV component’s bunch length and phase stability and 2) the commissioning of the laser room Hamamatsu C5680 streak camera system. We used a new readout camera based on the Prosilica GC1380 digital CCD with Gig-E readout that was compatible with our image processing tools. We observed a longer than expected UV bunch length of 4 ps σ and an unexpected peak multiplicity (with spacing of about 70 ps) in the synchronous sum of 5 UV micropulses. We have now systematically investigated the issues of whether the multiplicity was with each micropulse of the 3-MHz pulse train. We describe our extensive investigations that indicated both issues originated in the multi-pass amplifier. We have replaced the MPA with three single-pass devices, measured 3.5-ps bunch lengths without the multiplicity, and generated photoelectrons from the gun successfully.
TUP075 Commissioning Status of the ASTA Facility at Fermilab 537
  • A.H. Lumpkin, D.R. Broemmelsiek, D.J. Crawford, N. Eddy, D.R. Edstrom, E.R. Harms, A. Hocker, J.R. Leibfritz, J. Ruan, J.K. Santucci, G. Stancari, D. Sun, J.C.T. Thangaraj, R.M. Thurman-Keup, A. Warner, J. Zhu
    Fermilab, Batavia, Illinois, USA
  Funding: Work at Fermilab supported by Fermi Research Alliance, LLC under Contract No. DE-AC02- 07CH11359 with the United States Department of Energy.
Early commissioning results and status of the Advanced Superconducting Test Accelerator (ASTA) at Fermilab will be described. The ASTA facility consists of an L-band rf photocathode (PC) gun, two superconducting L-band rf booster cavities, transport lines, and an 8-cavity TESLA style cryomodule. Early results include first photoelectrons from the Cs2Te photocathode and operations at 3-5 MeV from the rf PC gun. The beam line with one 4-dipole chicane, extensive diagnostics, and 50-MeV spectrometer are being installed. The base beam profile imaging stations have been equipped with both YAG:Ce scintillators and optical transition radiation (OTR) screens, optical transport, and with 5 Mpix digital CCD cameras using Gig-E readout. A set of rf BPMs, wall current monitors, and toroids are also being implemented. Transport of OTR to a C5680 Hamamatsu streak camera is also planned for longitudinal profile information at the picosecond level. Downstream of this location is the 8-cavity cryomodule in which most cavities have been operated at the targeted 31.5 MV/m gradient. Initial beam measurements at 20 MeV and updated cryomodule results will be presented as available.