THB —  LINACs   (21-Jun-12   10:30—12:30)
Chair: J.A. Nolen, ANL, Argonne, USA

Paper	Title	Page
THB01	New Developments in Low-Z Gas Stripper Sstem at RIKEN Radioactive Isotope Beam Factory (RIBF)	199
	H. Okuno, N. Fukunishi, H. Hasebe, H. Imao, O. Kamigaito, M. Kase, H. Kuboki RIKEN Nishina Center, Wako, Japan
	Electron stripping process from heavy ion in material is a useful tool in accelerator complex to give higher charge state of the ion, allowing its effective acceleration. This process is competed with electron capture process and reach to the equilibrium charge state. Carbon foils is convenient for charge stripper but have short lifetime due to thermal stress and sputtering in the case of high power beam of heavy ion such as uranium. Gas is basically free from lifetime but gives lower charge state due to absent of density effect. Therefore, charge stripper especially for uranium beams at 10-20 MeV/u could be a bottle-neck problem in high power heavy ion facility such as RIBF, FRIB and FAIR. A charge stripper using low-Z gas (He or H2) is an important candidate to solve the problem because the high equilibrium mean charge states for the low-Z gas stripper are expected due to the suppression of the electron capture process. This presenation will describe the results for the develeopments and tests of He gas stripper for uranium beams at 11 MeV/u.
	Slides THB01 [7.108 MB]
THB02	New Design for the SARAF Phase II Linac	206
	B. Mustapha, Z.A. Conway, M.P. Kelly, A. Kolomiets, S.V. Kutsaev, P.N. Ostroumov ANL, Argonne, USA J. Rodnizki Soreq NRC, Yavne, Israel
	Funding: This work was supported by the ANL WFO No. 85Y47. We have developed a new design for the 40 MeV/u - 5 mA proton/deuteron SARAF Phase-II Linac. It includes a RFQ, room-temperature bunchers and two types of SC cavities. The new design is based on highly optimized ring-shaped HWR structures operating at 176 MHz, the same frequency as the current SARAF Phase-I linac. We will first present the optimized design of all the components from the RFQ to the SC cavities, then the proposed linac layout, and finally the results of end-to-end beam dynamics simulations including machine errors, realistic corrections and beam loss analysis.
	Slides THB02 [2.634 MB]
THB03	Design Sudy for Front-End System at Rare Isotope Science Project (RISP)	207
	E.-S. Kim KNU, Deagu, Republic of Korea J. Bahng, J.G. Hwang, S.W. Jang Kyungpook National University, Daegu, Republic of Korea B. Choi, D. Jeon, B. Kim, H. Kim, S.K. Kim IBS, Daejeon, Republic of Korea
	Heavy ion beams of 400 kW and 70 kW are generated at the RISP by in-flight and ISOL methods, respectively. Front-End system in the RISP consists of 28 GHz superconducting ECR-IS with 10 keV/u, LEBT with two-bends and a multi-harmonic buncher, a RFQ with 81.25 MHz and 300 keV/u, and MEBT with two re-bunchers. The design studies have been performed to optimize the beam and accelerator parameters to meet the required design goals. It is shown that the front-end simulations results can provide the two-charge state beams up to uranium to upstream linac with the required beam emittances. In this paper, we present the design results for the front-end system and on the beam dynamics.
	Slides THB03 [1.942 MB]
THB04	Development of the Intensity and Quality of the Heavy Ion Beams at GSI	211
	L.A. Dahl, W.A. Barth, M.C. Bellachioma, L. Groening, O.K. Kester, M.M. Kirk, D. Ondreka, N. Pyka, P.J. Spiller, J. Stadlmann, H. Vormann, S.G. Yaramyshev GSI, Darmstadt, Germany L.H.J. Bozyk, Y. El-Hayek FIAS, Frankfurt am Main, Germany C. Xiao IAP, Frankfurt am Main, Germany
	For injection into the future FAIR SIS100 synchrotron the GSI linear accelerator UNILAC and synchrotron SIS18 have to provide 1.5·1011 p/spill for the reference U28+ beam. The MeVVa ion source extracts 37 emA of U4+ beam. For improved transmission the RFQ vanes were revised and exchanged. A new ion source terminal with straightforward beam injection into the RFQ is calculated and partly realized for loss free beam transport to the RFQ. To improve the quality of the space charge dominated beam in the DFFD periodic focussing Alvarez section a transverse 4th order resonance was investigated by simulations and experimentally. The multi turn beam injection into the SIS18 requires emittances below βγεx/βγεy=0.8/2.5 [μm]. This suggests introducing a new concept for emittance transfer by solenoidal stripping. A set-up for experimental proof of principle will be installed at the foil stripper. The SIS18 has been equipped with NEG-coated chambers for all magnets and the injection septum. Newly installed ion catchers improve especially the dynamic vacuum pressure. The effect on progress in beam quality development and intensity will be reported.
	Slides THB04 [9.809 MB]
THB05	The HITRAP Decelerator and Beam Instrumentation	217
	F. Herfurth, Z. Andjelkovic, W.A. Barth, K. Brantjes, G. Clemente, L.A. Dahl, S. Fedotova, P. Gerhard, M. Kaiser, O.K. Kester, H.J. Kluge, C. Kozhuharov, M.T. Maier, D. Neidherr, W. Quint, A. Reiter, T. Stöhlker, G. Vorobjev, S.G. Yaramyshev GSI, Darmstadt, Germany U. Ratzinger, A. Schempp IAP, Frankfurt am Main, Germany
	A linear decelerator is being commissioned for heavy, highly-charged ions (HCI) at GSI in Darmstadt/Germany. HCI with only one or few electrons are interesting systems for many different experiments as for instance precision tests of the theory of quantum electrodynamics (QED). In order to transform heavy HCI produced at 400 MeV/u to stored and cooled HCI at low energy the linear decelerator facility HITRAP has been setup behind the experimental storage ring (ESR). The ions are decelerated in the ESR from 400 to 4 MeV/u, cooled and extracted. The ions are then matched to an IH-structure using a double drift buncher, decelerated from 4 to 0.5 MeV/u in the IH, and then down to 6 keV/u in a 4-rod RFQ. To detect and analyze the weak and sparse ion bunches a new type of energy analyzing detector has been developed along with improvements to other “standard” beam instrumentation. One million highly charged ions have been decelerated with the IH from 400 MeV/u to about 0.5 MeV/u per cycle. The RFQ has shown in off-line tests to decelerate ions, however, the measured acceptance does not fit the ion beam from the IH. This requires a refined design, which is underway.
	Slides THB05 [2.925 MB]