Abstracts Brochure - CERN

TUPLS — Poster Session 27-Jun-06 16:00 - 18:00
Measurement of the Extraction Kicker System in J-PARC RCS
Kicker magnet system in the J-PARC RCS
is now under construction at JAEA (Japan
Atomic Energy Agency). Their role in RCS
is to kick the accelerated 3 GeV proton beam
J. Kamiya, M.K. Kuramochi, T. Takayanagi, T.U. Ueno (JAEA/J-
PARC)
to the following extraction line at a repetition rate of 25 Hz. There are three kinds of kicker magnets (S, M, L),
distinguished by the difference in the size of their apertures. The specification of 2 % is required on the magnetic field
in terms of homogeneity in time and space from the beam optical point of view. The required flatness of the temporal
uniformity was accomplished by superposing the waveforms of the two kicker magnet*. The required specification
to the special uniformity is also very severe to achieve because our kicker magnet is designed with a large aperture
in order to accept a maximum beam power of 1 MW. We established the search coil as a detector and 3-axes stage to
perform magnetic field mapping. In order to reduce the signal noises and detect the stable output signals, matching
register and integrated circuit were carefully selected. The 3-axes stage was precisely aligned. The distribution of the
magnetic field (By) and integrated BL were systematically measured for the three types of kickers.
*J. Kamiya et al. “Magnetic field measurement of the extraction kicker magnet in J-PARC RCS,” submitted for
publication to the proceedings of the 19th International Conference on Magnet Technology.
Experimental Results of the Shift Bump Magnet in the J-PARC 3-GeV RCS
The shift bump magnet produces a fixed
main bump orbit to merge the injection beam
into the circulating beam. In order to control
the injection beam for the short injection time
T. Takayanagi, Y. Irie, J. Kamiya, M. Watanabe, M. Yoshimoto
(JAEA/J-PARC) T. Kawakubo, I. Sakai (KEK)
(500 microseconds) with sufficient accuracy, the shift bump magnet needs a wide uniform magnetic field and the high
speed exciting pattern of the high current. The magnetic field design and the structural analysis of the shift bump
magnets have been performed using three-dimensional electromagnetic analysis code and mechanical analysis code,
respectively. The magnetic field distributions were measured with a long search coil, thus giving a BL product over a
magnet gap area. The temperature distributions at the various points of the magnet were measured by thermocouples
over 24 hours till they saturated. General trend of these measurements agrees well with calculations.
Recent Status of Injection and Extraction System of 3GeV RCS at J-PARC
The injection and extraction system for 3GeV
RCS (Rapid Cycling Synchrotron) at J-PARC
(Japan Proton Accelerator Research Complex)
have many challenging issues, in order
M. Yoshimoto, J. Kamiya, M. Kinsho, M.W. Masao, T. Takayanagi,
O. Takeda (JAEA/J-PARC)
to realize MW beam in the RCS ring. The system is consisted in 3 parts, such as the injection line, the dump line,
and the extraction line. And they are constructed from many kinds of components, such as DC and pulse magnets, a
charge exchange system, beam monitors, titanium and ceramic vacuum chamber, a beam dump, and so on. Up to now,
final designs are accomplished and developments and experiments of some components are carried out. In this presentation,
summary of the injection and extraction system, recent status of developments, and beam commissioning
scheme for beam injection and extraction are introduced.
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