Abstracts Brochure - CERN

TUPLS — Poster Session 27-Jun-06 16:00 - 18:00
calculations of electrodynamic characteristics of the accelerating structure of the interdigital type. The peculiarities
of the construction of the accelerating structure are described.
The Spallation Neutron Source (SNS) Superconducting Linac: Installation, Commissioning
and Initial Operation
The SNS superconducting linac accelerates
H − ions from 187 MeV to about 1 GeV. During
the past year, installation of cryomodules,
warm sections between cryomodules,
vacuum systems and instrumentation was
completed and all the systems were tested
and commissioned with beam. Operation of
the 81 superconducting cavities at 2.1 and 4.2
K was carried out with pulsed gradients exceeding
the original specifications of 10.1 and
15.6 MV/m for medium and high beta cavities,
respectively. Maximum gradients have
reached an average of about 18 MV/m for
I.E. Campisi, A.V. Aleksandrov, D.E. Anderson, S. Assadi, W. Blokland,
F. Casagrande, M.S. Champion, P. Chu, S.M. Cousineau,
M.T. Crofford, R.I. Cutler, V.V. Danilov, W.R. DeVan, C. Deibele,
G.W. Dodson, J.J. Error, J. Galambos, M. Giannella, D.P. Gurd, P.A.
Gurd, T.W. Hardek, D.R. Hatfield, S. Henderson, J.A. Holmes, N.
Holtkamp, M.P. Howell, T. Hunter, D.-O. Jeon, Y.W. Kang, K.-U.
Kasemir, S.-H. Kim, Z. Kursun, P. Ladd, H. Ma, M.P. McCarthy,
G.R. Murdoch, T.A. Pelaia, M.A. Plum, K.R. Rust, T.J. Shea, A.P.
Shishlo, C. Sibley III, M.P. Stockli, D. Stout, W.H. Strong, J.Y. Tang,
A.V. Vassioutchenko, R.F. Welton, M. Wezensky, D.C. Williams, E.
Williams, P.A. Wright, Y. Zhang (ORNL) R. Kersevan (ESRF)
both medium and high beta cavities, with several cavities exceeding 20 MV/m. In general, heavy field emission has
been observed in most cavities as being the limiting factor. Routinely, the 4.2 K temperature has been used to decrease
power consumption, without any decrease in cavity gradient performance. Beam commissioning has been achieved
both at 4.2 K and at 2.1 K with final energies exceeding 950 MeV, with a few cavities not operating. The experience of
operating the superconducting linac with beam and the cavities’ performance at 4.2 and 2.1 K will be presented.
Design of a Low Energy Electron Cooler for the Heidelberg CSR
The electrostatic Cryogenic Storage Ring
(CSR) is currently being designed at MPI-K H. Fadil, M. Grieser, D. Orlov, A. Wolf (MPI-K)
in Heidelberg. This ring will utilize electrostatic
deflectors and focusing elements, and will store ions with kinetic energies in the range 20∼300 keV (E/Q) to be
mainly utilized in atomic and molecular physics experiments. The CSR will be equipped with a compact magnetic
electron cooler, which will serve the double purpose of phase space compression of the stored ion beam as well as
an electron target for recombination experiments. The cryogenic photocathode source, developed for the Heidelberg
TSR, will be used to provide extremely cold magnetically guided electron beams. The maximum cooling electron
energy is 165 eV and the usual operation energy for 20 keV protons will be about 10 eV. The cooler will fit in the
2.8 m straight section of the ring. The device will be installed inside the outer vacuum chamber of the CSR, and the
magnetic confinement of the electrons will be provided with high temperature superconducting coils. The design of
the magnets of the CSR electron cooler will be presented in this paper.
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