HIAT 2012 - List of Authors (Barth, W.A.)

Author: Barth, W.A.

Paper	Title	Page
WEC05	Design Studies for a New Heavy Ion Injector Linac for FAIR	191
	B. Schlitt, W.A. Barth, G. Clemente, W. Vinzenz GSI, Darmstadt, Germany
	As the GSI UNILAC started operation in 1975, it will be more than 40 years old when the commissioning of the future Facility for Antiproton and Ion Research (FAIR) at GSI will start. To assure reliable operation for FAIR and to provide beams for a variety of experiments, three separate linacs are proposed: 1.) A new superconducting cw heavy-ion linac behind the upgraded high charge state injector HLI shall provide ion beams with high duty cycle and adjustable energy in the MeV/u region for the super-heavy element program as well as for further UNILAC experiments. 2.) A dedicated 70 MeV proton linac will serve as injector for the FAIR pbar physics program. 3.) To deliver high-intensity heavy-ion beams for FAIR, the existing post-stripper linac should be replaced by a new high energy linac with short beam pulses, low pulse repetition rate, and fixed end energy. Conceptual design studies for the latter machine using 10⁸ MHz IH-type drift tube structures will be presented, including a proposal to increase the ion charge states for synchrotron injection as well as a linac beam energy upgrade using 325 MHz CH structures.
	Slides WEC05 [6.013 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]

WEC03	The SC CW LINAC Demonstrator – 1st Test of an SC CH-cavity with Heavy Ions	182
	S. Mickat, L.A. Dahl GSI, Darmstadt, Germany M. Amberg, K. Aulenbacher, W.A. Barth, V. Gettmann, S. Mickat HIM, Mainz, Germany D. Bänsch, F.D. Dziuba, D. Mäder, H. Podlech, U. Ratzinger, R. Tiede IAP, Frankfurt am Main, Germany
	The superconducting (sc) continuous wave (cw) LINAC Demonstrator is a collaboration project between GSI, the Helmholtz Institute Mainz (HIM), and the Institute for Applied Physics (IAP) at the Goethe University Frankfurt. The aim is a full performance test of a 217 MHz sc Crossbar H-mode (CH) cavity, which provides gradients of 5.1 MV/m at a total length of 0.69 m. In addition the Demonstrator comprises two 9.3 Tesla sc solenoids. The configuration of a CH-cavity embedded by two sc solenoids is taken from a conceptual layout of a new sc cw LINACwith nine CH-cavities and seven solenoids. Such an accelerator is highly desired by a broad community of users requesting heavy ion beam energies in the Coulomb barrier range. A successful test of such an sc multigap structure are an important milestone towards the proposed cw-LINAC.
	Slides WEC03 [1.842 MB]