Abstracts Brochure - CERN

MOPCH126
MOPCH127
26-Jun-06 16:00 - 18:00 MOPCH — Poster Session
structure base. We study an alternative version
with radial focusing by an electron beam guided by external magnetic field. Our PIC simulation (preliminary
made in the approximation of a slowly disturbed E-beam) shows: the proton beam with initial energy of 100keV, current
0.3A is accelerated in the IH-resonator up to 3MeV; the transmission coefficient is 99%; the transversal emittance
at the linac outlet is 0.40 mmxmrad while at the input it is 0.32 mmxmrad. At the acceleration rate and RF frequency
comparative to the LEDA linac, RF ohmic loses are less by one order; the input RF power is about 1.1MW. The E-beam
power is varied from 2 to 10MW; the guided magnetic field is 3-5kOe. Under the E-beam recuperation efficiency about
90%, the total acceleration efficiency of the protons is 40-50%. Further acceleration can be realized in next sections of
traditional type. For injection of the wide proton beam into the initial section, an input "funnel" which is formed by
the E-beam and external magnetic field, and can compress the proton beam down to the radius 1-2mm, is simulated.
Accelerator Research on the Rapid Cycling Synchrotron at IPNS
G.E. McMichael, F.R. Brumwell, L. Donley, J.C. Dooling, W. Guo,
Q.B. Hasse, D. Horan, R. Kustom, M.K. Lien, M.E. Middendorf,
M.R. Moser, S. Wang (ANL)
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The Intense Pulsed Neutron Source (IPNS)
at Argonne National Laboratory is a national
user facility for neutron scattering. Neutrons
are produced by 70 ns pulses of protons (∼3x
10 12 protons per pulse) impacting a depleted-
uranium target at a pulse repetition rate of 30 Hz. Three accelerators in series (a 750 keV Cockcroft-Walton, 50 MeV
Alvarez linac accelerating H − ions, and a 450 MeV rapid-cycling proton synchrotron) provide the beam that is
directed to the target. New diagnostics and a third rf cavity that can be operated at either the fundamental or second
harmonic of the ring frequency have recently been installed and an experimental program established to try to gain
understanding of an instability that limits the charge-per-bunch in the RCS. This program will be described, and
preliminary results presented.
SNS Warm Linac Commissioning Results
A.V. Aleksandrov, S. Assadi, W. Blokland, P. Chu, S.M. Cousineau,
V.V. Danilov, C. Deibele, J. Galambos, S. Henderson, D.-O. Jeon,
M.A. Plum, A.P. Shishlo (ORNL)
The Spallation Neutron Source accelerator
systems will deliver a 1.0 GeV, 1.4 MW proton
beam to a liquid mercury target for neutron
scattering research. The accelerator complex
consists of an H − injector, capable of produc-
ing one-ms-long pulses at 60Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator
ring and associated transport lines. The 2.5MeV beam from the Front End is accelerated to 86 MeV in the Drift Tube
Linac, then to 185 MeV in a Coupled-Cavity Linac and finally to 1 GeV in the Superconducting Linac. The staged
beam commissioning of the accelerator complex is proceeding as component installation progresses. Current results
of the beam commissioning program of the warm linac will be presented including transverse emittance evolution
along the linac, longitudinal bunch profile measurements at the beginning and end of the linac, and beam loss study.