Author: Bogacz, S.A.
Paper Title Page
MOPPC045 Scaled Electron Model of a Dogbone Muon RLA with Multi-pass Arcs 235
  • S.A. Bogacz, A. Hutton, G.A. Krafft, V.S. Morozov, Y. Roblin
    JLAB, Newport News, Virginia, USA
  • K.B. Beard, R.P. Johnson
    Muons, Inc, Batavia, USA
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by USDOE STTR Grant DE-FG02-08ER86351.
The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons for a future Neutrino Factory and Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over single pass or pulsed arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme in which a 4.35 MeV/c electron beam is injected in the middle of a 2.9 MeV/pass linac with two double-pass return arcs, and is accelerated to 17.4 MeV/c in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it feasible to utilize the existing technologies.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.
TUPPD008 Recent Progress Toward a Muon Recirculating Linear Accelerator 1422
  • K.B. Beard
    Muons, Inc, Batavia, USA
  • M. Aslaninejad, C. Bonţoiu, A. Kurup, J.K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • S.A. Bogacz, V.S. Morozov, Y. Roblin
    JLAB, Newport News, Virginia, USA
  Both Neutrino Factories (NF) and Muon Colliders (MC) require very rapid acceleration due to the short lifetime of muons. After a capture and bunching section, a linac raises the energy to about 900 MeV, and is followed by one or more Recirculating Linear Accelerators (RLA), possibly followed by a Rapid Cycling Synchrotron (RCS) or Fixed-Field Alternating Gradient (FFAG) ring. A RLA reuses the expensive RF linac section for a number of passes at the price of having to deal with different energies within the same linac. Various techniques including pulsed focusing quadrupoles, beta frequency beating, and multipass arcs have been investigated via simulations to improve the performance and reduce the cost of such RLAs.  
TUPPD011 Studies of the Twin Helix Parametric-resonance Ionization Cooling Channel with COSY INFINITY 1428
  • J.A. Maloney, K.B. Beard, R.P. Johnson
    Muons, Inc, Batavia, USA
  • A. Afanasev
    GWU, Washington, USA
  • S.A. Bogacz, Y.S. Derbenev, V.S. Morozov
    JLAB, Newport News, Virginia, USA
  • B. Erdelyi
    Northern Illinois University, DeKalb, Illinois, USA
  Funding: Supported in part by SBIR Grant DE-SC00005589. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A primary technical challenge to the design of a high luminosity muon collider is an effective beam cooling system. An epicyclic twin-helix channel utilizing parametric-resonance ionization cooling has been proposed for the final 6D cooling stage. A proposed design of this twin-helix channel is presented that utilizes correlated optics between the horizontal and vertical betatron periods to simultaneously focus transverse motion of the beam in both planes. Parametric resonance is induced in both planes via a system of helical quadrupole harmonics. Ionization cooling is achieved via periodically placed wedges of absorbing material, with intermittent rf cavities restoring longitudinal momentum necessary to maintain stable orbit of the beam. COSY INFINITY is utilized to simulate the theory at first order. The motion of particles around a hyperbolic fixed point is tracked. Comparison is made between the EPIC cooling channel and standard ionization cooling effects. Cooling effects are measured, after including stochastic effects, for both a single particle and a distribution of particles.
WEPPR096 Recirculating Beam Breakup Study for the 12 GeV Upgrade at Jefferson Lab 3162
  • I. Shin, S. Ahmed, R.M. Bodenstein, S.A. Bogacz, T. Satogata, M. Stirbet, H. Wang, Y. Wang, B.C. Yunn
    JLAB, Newport News, Virginia, USA
  • I. Shin
    University of Connecticut, Storrs, Connecticut, USA
  Two new high gradient C100 cryostats with a total of 16 new cavities were installed at the end of the CEBAF south linac during the 2011 summer shutdown as part of the 12 GeV upgrade project at Jefferson Lab. We ran recirculating beam breakup (BBU) study in November 2011 to evaluate CEBAF low energy performance, measure transport optics, and evaluate BBU thresholds due to higher order modes (HOMs) in these cavities. This paper discusses the experiment setup, cavity measurements, machine setup, optics measurements, and lower bounds on existing CEBAF C100 BBU thresholds established by this experiment.