Abstracts Brochure - CERN

TUPLS — Poster Session 27-Jun-06 16:00 - 18:00
Matching of High Intensity Ion Beams to an RFQ: Comparison of PARMTEQ and IGUN
Simulations
The classical way of matching an ion source
to the low energy accelerator RFQ generally R. Becker, R.A. Jameson (IAP)
is performed by adjusting the matching optics
of the LEBT to provide the rms ellipse twiss parameter requirements of the RFQ shaper section. By matching
to the rms parameters (the equivalent rms beam method) the actual shape of the distribution plays a smaller role
according to F. Sacherer. In many cases, however, the matching optics are creating not only aberrations to the ion
beam but also a very non-elliptical shape of the emittance figure, and a more exact match may be required. As a way
out, an ion extraction program (IGUN) has been modified to also take into account the rf-focusing of non-modulated
RFQ vanes in the shaper section. This makes it feasible to use this program for the simulation from the ion source
plasma until the beginning of modulation inside the RFQ, and it can also handle dc fields in the injection region of
the RFQ. In order to demonstrate the differences of both approaches we apply them to well defined experimentally
proved designs of RFQ shaper sections.
Sputter Probes and Vapor Sources for ECR Ion Sources
Sputter probes are a promising method for
injecting controlled quantities of metallic elements
inside ECRIS ion source, provided
that sputter rate can be controlled, so that
M. Cavenago, A. Galatà, M. Sattin (INFN/LNL) T. Kulevoy, S. Petrenko
(ITEP)
high charge states and low sample consumption rate will be attained. Moreover pressure at the probe and inside
source should be different. With a simple differential pumping scheme and a sputter probe at 25 mm from ECRIS
plasma, a 200 nA current of 120Sn 18+ was easily obtained. Typical results (for Sn and Ti) of an inductively heated rf
oven are discussed for comparison. Improvements of sputter probe concept and geometry are also described.
Pulsed Bending Magnet for the Injection Line of J-PARC Main Ring
Japan Proton Accelerator Research Complex
(J-PARC) is under construction with a collaboration
between Japan Atomic Energy
Agency (JAEA) and High Energy Accelera-
K. Koseki, H. Kobayashi, H. Nakayama, K.O. Okamura, M.J. Shirakata,
M. Tawada (KEK)
tor Research Organization (KEK). The J-PARC consists of a 200 MeV linac, a 3 GeV rapid-cycle synchrotron (RCS)
and a 50 GeV synchrotron (MR). As an extracted beam from the RCS is delivered both to the Materials and Life
Science Facility and to the MR, two beam transport lines, 3-NBT and 3-50BT, are constructed. A selection of beam
transport line is performed by a pulsed bending magnet. To obtain a sufficient bending radius, a field strength of
1.21 Tesla with a sharp rise time of less than 40 msec is required. It was found that an effect induced by eddy current
disturb the sharp rise of dipole field. Details of the measured magnetic field is discussed at the conference. A unique
configuration of a power supply system is also presented.
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