• K.T. McDonald
  PU, Princeton, New Jersey
• J.R.J. Bennett
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• O. Caretta, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• A.J. Carroll, V.B. Graves, P.T. Spampinato
  ORNL, Oak Ridge, Tennessee
• I. Efthymiopoulos, A. Fabich, F. Haug, J. Lettry, M. Palm, H. Pereira
  CERN, Geneva
• H.G. Kirk, H. Park, T. Tsang
  BNL, Upton, Long Island, New York
• N.V. Mokhov, S.I. Striganov
  Fermilab, Batavia

The MERIT (MERcury Intense Target) experiment was run in the fall of 2007 using 14 and 24 GeV intense proton beams from the CERN PS. It is a proof-of-principle experiment designed to validate a target concept for producing an intense muon source for a future muon collider or neutrino factory. The experiment successfully demonstrated a target technique for multi-MW proton beams that utilizes a free-flowing liquid metal jet within the confines of a high-field solenoid. We describe the experimental strategy and parameters, as well as the results obtained and their implications for future muon-based accelerator facilities.

Slides

• I. Efthymiopoulos, A. Fabich, A. Grudiev, F. Haug, J. Lettry, M. Palm, H. Pereira, H. Pernegger, R.R. Steerenberg
  CERN, Geneva
• J.R.J. Bennett
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• O. Caretta, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• A.J. Carroll, V.B. Graves, P.T. Spampinato
  ORNL, Oak Ridge, Tennessee
• H.G. Kirk, H. Park, T. Tsang
  BNL, Upton, Long Island, New York
• K.T. McDonald
  PU, Princeton, New Jersey
• N.V. Mokhov, S.I. Striganov
  Fermilab, Batavia

The MERIT experiment is a proof-of-principle test of a target system for high power proton beam to be used as front-end for a neutrino factory complex or a muon collider. The experiment took data in autumn 2007 with the fast extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of about 30·10¹² protons per pulse. We report results from the portion of the MERIT experiment in which separated beam pulses were delivered to a free mercury jet target with time intervals between pulses varying from 2 to 700 microseconds. The analysis is based on the responses of particle detectors placed along side and downstream of the target.

• H.G. Kirk, H. Park, T. Tsang
  BNL, Upton, Long Island, New York
• J.R.J. Bennett
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• O. Caretta, P. Loveridge
  STFC/RAL, Chilton, Didcot, Oxon
• A.J. Carroll, V.B. Graves, P.T. Spampinato
  ORNL, Oak Ridge, Tennessee
• I. Efthymiopoulos, A. Fabich, F. Haug, J. Lettry, M. Palm
  CERN, Geneva
• K.T. McDonald
  PU, Princeton, New Jersey
• N.V. Mokhov, S.I. Striganov
  Fermilab, Batavia

We report on the analysis of data collected from the optical diagnostics of the MERIT experiment which was run at CERN in the fall of 2007. The breakup of the free mercury jet resulting from the impact of intense proton beams from the CERN PS within a magnetic field environment is described.

• T. Tsang, S. Bellavia, R. Connolly, D.M. Gassner, Y. Makdisi, M.G. Minty, T. Russo, P. Thieberger, D. Trbojevic, A. Zelenski
  BNL, Upton, Long Island, New York

A gas fluorescence beam profile monitor has been realized at the relativistic heavy ion collider (RHIC) using the polarized atomic hydrogen gas jet. RHIC proton beam profiles in the vertical plane are obtained as well as measurements of the width of the gas jet in the beam direction. For gold ion beams, the fluorescence cross section is sufficiently large so that profiles can be obtained from the residual gas alone, albeit with long light integration times and lower number of Au ions than protons. We estimate the fluorescence cross-section of 100 GeV protons and Au ions on hydrogen gas to be 6.6x10-21 cm² ~1.7x10-16 cm², respectively*. We calculate the beam emittance to provide an independent measurement of the RHIC beam. This optical beam diagnostic technique, utilizing the beam induced fluorescence from injected or residual gas, represents a step towards the realization of a simple and truly noninvasive beam monitor for high-energy particle beams together with a wall-current-monitor system and/or a low light level optical temporal measurement system, a 3-dimensional particle beam profile system can be envisioned providing routine diagnosis of high-energy particle beams.

*T. Tsang, et. al., Rev. Sci. Instrum. 79, 105103 (2008).