THP1WC —  WG-C   (21-Jun-18   14:00—15:30)
Chair: F.G. Garcia, Fermilab, Batavia, Illinois, USA
Paper Title Page
THP1WC01 MEBT Laser Notcher (Chopper) for Booster Loss Reduction -1
 
  • D.E. Johnson, C.M. Bhat, S. Chaurize, K.L. Duel, T.R. Johnson, P.R. Karns, W. Pellico, B.A. Schupbach, K. Seiya, D. Slimmer
    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 Fermilab Booster, which utilizes multi-turn injection and adiabatic capture, the extraction gap (aka "notch") has been created in the ring at injection energy using fast kickers which deposit the beam in a shielded absorber within the accelerator tunnel. This process, while effective at creating the extraction notch, was responsible for a significant fraction of the total beam power loss in the Booster tunnel and created significant residual activation within the Booster tunnel in the absorber region and beyond. With increasing beam demand from the Experimental Program, the Fermilab Proton Improvement Plan (PIP) initiated an R&D project to build a laser system to create the notch within a linac beam pulse at 750 keV, where activation in not an issue. This talk will discuss moving from R&D to an operational laser system and its integration into the accelerator complex. We will also cover the loss reduction in the Booster, increased efficiency, and increased proton throughput. We will touch on other potential applications for this bunch-by-bunch neutralization approach.
 
slides icon Slides THP1WC01 [26.294 MB]  
 
THP1WC02 Status of Proof-of-Principle Demonstration of 400 MeV H-Stripping to Proton by Using Only Lasers at J-PARC -1
 
  • P.K. Saha, H. Harada, M. Kinsho, A. Miura, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie, I. Yamane
    KEK, Ibaraki, Japan
  • Y. Michine, H. Yoneda
    University of Electro-communications, Tokyo, Japan
 
  In order to make a breakthrough in the conventional H charge-exchange injection done by using solid stripper foil, we proposed a completely new method H stripping to proton by using only lasers. Extremely high residual radiation due foil beam interaction beam losses as well as unreliable and short lifetime of the stripper foil are already serious issues in all existing high intensity proton machines. To established our new principle, experimental studies for a proof-of-principle (POP) demonstration at 400 MeV H beam energy is under preparation at J-PARC. A vacuum chamber for the POP demonstration has already been installed at the end section of 400 MeV H beam transport of J-PARC Linac. The H beam manipulations, numerical simulations as well as the laser beam studies are in progress. The present status of the POP demonstration of 400 MeV H stripping to protons by using only lasers are presented.  
slides icon Slides THP1WC02 [7.535 MB]  
 
THP1WC03 Design of 162-MHz CW Bunch-by-Bunch Chopper and Prototype Testing Results -1
 
  • A.V. Shemyakin, C.M. Baffes, J.-P. Carneiro, B.E. Chase, A.Z. Chen, J. Einstein-Curtis, D. Frolov, B.M. Hanna, V.A. Lebedev, L.R. Prost, G.W. Saewert, A. Saini, D. Sun
    Fermilab, Batavia, Illinois, USA
  • C.J. Richard
    NSCL, East Lansing, Michigan, USA
  • D. Sharma
    RRCAT, Indore (M.P.), India
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The PIP-II program of upgrades proposed for the Fermilab accelerator complex, is centered around a 800 MeV, 2 mA CW SRF linac. A unique feature of the PIP-II linac is the capability to form a flexible bunch structure by removing a pre-programmed set of bunches from a long-pulse or CW 162.5 MHz train, coming from the RFQ, within the 2.1-MeV Medium Energy Beam Transport (MEBT) section. The MEBT chopping system consists of two travelling-wave kickers working in sync followed by a beam absorber. The prototype components of the chopping system, two design variants of the kickers and a 1/4-size absorber, have been installed in the PIP-II Injector Test (PIP2IT) accelerator and successfully tested with beam of up to 5 mA. In part, one of the kickers demonstrated a capability to create an aperiodic pulse sequence suitable for synchronous injection into the Booster while operating at 500 V and average switching frequency of 44 MHz during 0.55 ms bursts at 20 Hz. This report presents the design of the PIP-II MEBT chopping system and results of prototypes testing at PIP2IT.
 
slides icon Slides THP1WC03 [4.615 MB]