DESIGN OF THE BEAM TRANSPORT SYSTEM FOR THE IPCR SSC
N. Kishida, Y. Yano, T. Wada,s. Motonaga, and H. Kamitsubo

The Institute of Physical and Chemical Research
Abstract
The beam transport system from RILAe(Riken Heavy Ion Linac Facility) toIPeR SSe is designed. The system is composed of a charge stripping and charge
selection part, subsequent achromatic beam transport line, and a beam opticalmatching system.
The purpose of the beam transport system is to bring the preaccelerated
beam from RILAe to the SSe and to change its properties according to the requirements of the SSe at injection point. The demanded performance of the beam transport system is as follows: (1) the system is required to transport the particles
of maximum magnetic rigidity of p=0.2354 GeV/c corresponding to a 238 u40+ beam of
0.84 MeV/A; (2) the system can transport the beam from RILAe which has verticaland horizontal emittance of 5 mm x 5 mrad• ~= 25~ mm•mrad and 0.3 % energy spread
without any beam losses; (3) achromatic transport is realizable; (4) the system
prepares the beam shape, dispersion and pulse length which the beam injection
system (see another part of this contributed paper) requires at the beam matching
point.
The computer program TRANSPORT is used to calculate beam optics to firstorderl). In designing the system cares are taken that quadrupole field gradients
do not exceed about 1.5 kGauss/cm and that each object waist is transformed into
an image waist independently of starting phase ellipse. Therefore the strengthof the magnetic elements are determined by only the magnetic rigidity of thebeam. The layout of the beam transport system is shown in Fig. 1. Each bending
part and each straight line are composed of an achromatfc tra\).sport system withmirror symmetry and a doubly telescopic system, respectively 2 J. So the shape of
the initial phase ellipse are unchangeably transported from an object to an image.
The transport system from So to S2 constitutes a charge stripping and charge
selection part, and it has enough momentum resolution to separate u39+ ions fromu4 D+ ions at slit S1. This is demonstrated in Fig. 2. The dipole magnet Ds
operates as switching magnet because of the beam from the injector AVF cyclotron
being injected through it. Therefore Ds and D7 have no face angle and thequadrupole triplet QT7 is used to get vertical focusing. Two quadrupole doublet
QD13 and QD14 constitute the beam matching system which matches horizontal andvertical phase ellipses to the sse acceptance. Momentum dispersion matching is
performed by the subsequent beam injection system.
It is pointed out that a central position phase space matching is very
important in high harmonics accelerations3 ). Now buncher calculations considering the above condition are under way. A possibility of beam sharing between
RILAe and the SSe is also investigated.
References1)2)3)

K.L. Brown et al., SLAe-91(1974)
F. Hinterberger, Nucl. Instr. and Meth. 111(1973)189
W.M. Schulte and H.L. Hagedoorn, IEEE Trans. Nucl. Sci. NS-26, 2(1979)2388-41-

Achromat ic Transport Systea

Double Te'lescopi c Systes

S0-52

from RIU.C

sl-sls 1 -s 4s 5 -s 6s 7 -s 1s,-slO•.-sss6 -s 7s,-s,

QS: Quadrupol e Sinqlet
OD: OU•drupol e Doublet
0'1': Quadrupol e Triplet.•r;.o 4r;TlQT2s,~050JFig. 1

Layou t of the beamtrans port system RI~.C tothesset.o be•• injection syat.e•
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Joi

~j_!If•Fig. 2 Singl e ray plot of U~O+ and u 39 + ionsof0.235 4 GeV/c . A charg e strip per is placed in s 0 anda charg e selec tion slit is place d in s .
1-42-