• O. Delferrière, D. Boutin, A. Dael, A. Drouart, C. Mayri, J. Payet, J.-M. Rifflet
  CEA, Gif-sur-Yvette

S3 (Super Sep­a­ra­tor Spec­trom­e­ter) [1] is a fu­ture de­vice de­signed for ex­per­i­ments with the very high in­ten­si­ty heavy ion sta­ble beams of SPI­RAL2. It will be set-up at the exit of the lin­ear ac­cel­er­a­tor LINAG at GANIL (Caen, France). It will in­clude a tar­get re­sis­tant to very high in­ten­si­ties, a first stage mo­men­tum achro­mat for pri­ma­ry beam sup­pres­sion, a sec­ond stage mass spec­trom­e­ter and a ded­i­cat­ed de­tec­tion sys­tem. This mass spec­trom­e­ter in­cludes a set of four large aper­ture quadrupole triplets with em­bed­ded mul­ti­po­lar cor­rec­tions. These mag­nets are a com­bi­na­tion of three mul­ti­poles which could be re­al­ized with su­per­con­duc­tor wound in flat race­track coils. To en­able the pri­ma­ry beam ex­trac­tion one triplet has to be opened on one side, which re­quires a care­ful de­sign of such a mul­ti­po­lar mag­net. This paper de­scribes the opened mul­ti­pole ge­om­e­try. It is adapt­ed to large aper­tures as demon­strat­ed by Opera 3d© mag­net­ic sim­u­la­tions [2], in­clud­ing har­mon­ic anal­y­sis and in­te­gral field ho­mo­gene­ity.

• R. Versteegen, O. Delferrière, O. Napoly, J. Payet, D. Uriot
  CEA, Gif-sur-Yvette

The In­ter­na­tion­al Lin­ear Col­lid­er ref­er­ence de­sign is based on a col­li­sion scheme with a 14 mrad cross­ing angle. Con­se­quent­ly, the de­tec­tor solenoid and the ma­chine axis do not co­in­cide. It pro­vokes a po­si­tion off­set of the beam at the In­ter­ac­tion Point in ad­di­tion to a beam size growth. These ef­fects are mod­i­fied by the in­ser­tion of the an­ti-DID (De­tec­tor In­te­grat­ed Dipole) aim­ing at re­duc­ing back­ground in the de­tec­tor. Fur­ther­more a crab cav­i­ty is nec­es­sary to re­store a 'head on' like col­li­sion, lead­ing to high­er lu­mi­nos­i­ty. This in­tro­duces new beam dis­tor­tions. In this paper, op­tics stud­ies and sim­u­la­tions of beam trans­port in the In­ter­ac­tion Re­gion tak­ing these el­e­ments into ac­count are pre­sent­ed. Cor­rec­tion schemes of the beam off­set and beam size growth are ex­posed and their as­so­ci­at­ed tol­er­ances are eval­u­at­ed.

• D. Boutin, M. Authier, F. Dechery, O. Delferrière, A. Drouart, J. Payet, D. Uriot
  CEA, Gif-sur-Yvette
• M. Amthor, H. Savajols, M.-H. Stodel
  GANIL, Caen
• S.L. Manikonda, J.A. Nolen
  ANL, Argonne

S3 (Super Sep­a­ra­tor Spec­trom­e­ter) [1] is a fu­ture de­vice de­signed for ex­per­i­ments with the high in­ten­si­ty heavy ion sta­ble beams of SPI­RAL2 [2] at GANIL (Caen, France). It will in­clude a tar­get re­sis­tant to these very high in­ten­si­ties, a first stage mo­men­tum achro­mat for pri­ma­ry beam ex­trac­tion and sup­pres­sion, a sec­ond stage mass spec­trom­e­ter and a ded­i­cat­ed de­tec­tion sys­tem. This spec­trom­e­ter in­cludes large aper­ture quadrupole triplets with em­bed­ded mul­ti­po­lar cor­rec­tions. To en­able the pri­ma­ry beam ex­trac­tion one triplet has to be opened on one side, which re­quires an ap­pro­pri­ate de­sign of such a mul­ti­po­lar mag­net. The final mass sep­a­ra­tion power re­quired for S3 needs a care­ful de­sign of the op­tics with a high level of aber­ra­tion cor­rec­tion. Mul­ti­ple sym­met­ric lat­tices were stud­ied for this pur­pose. A 4-fold sym­met­ric lat­tice and the achieved re­sults are de­scribed in this paper.

[1] A. Drouart et al., Nucl. Phys. A 834 (2010) 747c. [2] SPIRAL2, http://pro.ganil-spiral2.eu/spiral2