HIAT2015 - List of Authors (Barth, W.A.)

Paper	Title	Page
TUA1I02	Upgrade of the UNILAC for FAIR	139
	L. Groening, A. Adonin, W.A. Barth, X. Du, R. Hollinger, E. Jäger, M. Kaiser, S. Mickat, A. Rubin, P. Scharrer, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao, C. Zhang GSI, Darmstadt, Germany Ch.E. Düllmann HIM, Mainz, Germany H. Hähnel, U. Ratzinger, A. Seibel, R. Tiede IAP, Frankfurt am Main, Germany
	The UNIversal Linear Accelerator (UNILAC) at GSI has served as injector for all ion species from protons for uranium for the past four decades. In order to meet the requirements for the upcoming FAIR project the machine has to be revised. A dedicated uranium source branch is under design. It has to provide up to 20 emA of 238U⁴⁺ at 2.2 keV/u to the entrance of the RFQ. The latter needs to be re-designed aiming at lower electric surface fields for sparking mitigation. The operational flexibility of the subsequent MEBT will be enhanced. We report on recent achievements on enhancing the stripping efficiency from U⁴⁺ to U²⁸⁺ by employing a pulsed jet of hydrogen gas. The stripper section may also include an option to provide a round-to-flat adapter shrinking the horizontal emittance at the expense of the vertical one. The existing post-stripper DTL is in operation since 40 years and will be fully re-designed. An optimized drift tube shape increases the shunt impedance, varying stem orientations shall mitigate parasite rf-modes, and asymetric and enhanced quadrupole focusing will preserve the beam flatness. The contribution will describe the various upgrade measures.
	Slides TUA1I02 [4.477 MB]
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TUA1C01	A Pulsed Gas Stripper for Stripping of High-Intensity, Heavy-Ion Beams at 1.4 MeV/u at the GSI UNILAC	144
	P. Scharrer, W.A. Barth, Ch.E. Düllmann, J. Khuyagbaatar HIM, Mainz, Germany W.A. Barth, M. Bevcic, Ch.E. Düllmann, L. Groening, K.P. Horn, E. Jäger, J. Khuyagbaatar, J. Krier, P. Scharrer, A. Yakushev GSI, Darmstadt, Germany Ch.E. Düllmann, P. Scharrer Mainz University, Mainz, Germany
	The GSI UNILAC in combination with SIS18 will serve as a high-current, heavy-ion injector for the future FAIR. It has to meet high demands in terms of beam brilliance at a low duty factor (100 mus beam pulse length, 2.7 Hz repetition rate). An advanced 1.4 MeV/u gas stripper setup has been developed, aiming at an enhanced yield into the required charge states. The setup delivers short, high-density gas pulses in synchronization with the beam pulse. This provides an increased gas density at a reduced gas load for the differential pumping system. In recent measurements, high-intensity, heavy-ion beams of U⁴⁺ were successfully stripped and separated for the desired charge state. The modified stripper setup, as well as major results, are presented, including a comparison to the present gas stripper based on a N₂ gas-jet. The stripping efficiency into the desired 28⁺ charge state was significantly increased by up to 60 % using a hydrogen stripper target while the beam quality remained similar.
	Slides TUA1C01 [2.035 MB]
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Paper

Title

Page

Upgrade of the UNILAC for FAIR

139

L. Groening, A. Adonin, W.A. Barth, X. Du, R. Hollinger, E. Jäger, M. Kaiser, S. Mickat, A. Rubin, P. Scharrer, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao, C. Zhang
GSI, Darmstadt, Germany
Ch.E. Düllmann
HIM, Mainz, Germany
H. Hähnel, U. Ratzinger, A. Seibel, R. Tiede
IAP, Frankfurt am Main, Germany

The UNIversal Linear Accelerator (UNILAC) at GSI has served as injector for all ion species from protons for uranium for the past four decades. In order to meet the requirements for the upcoming FAIR project the machine has to be revised. A dedicated uranium source branch is under design. It has to provide up to 20 emA of 238U⁴⁺ at 2.2 keV/u to the entrance of the RFQ. The latter needs to be re-designed aiming at lower electric surface fields for sparking mitigation. The operational flexibility of the subsequent MEBT will be enhanced. We report on recent achievements on enhancing the stripping efficiency from U⁴⁺ to U²⁸⁺ by employing a pulsed jet of hydrogen gas. The stripper section may also include an option to provide a round-to-flat adapter shrinking the horizontal emittance at the expense of the vertical one. The existing post-stripper DTL is in operation since 40 years and will be fully re-designed. An optimized drift tube shape increases the shunt impedance, varying stem orientations shall mitigate parasite rf-modes, and asymetric and enhanced quadrupole focusing will preserve the beam flatness. The contribution will describe the various upgrade measures.

Slides TUA1I02 [4.477 MB]

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TUA1C01

A Pulsed Gas Stripper for Stripping of High-Intensity, Heavy-Ion Beams at 1.4 MeV/u at the GSI UNILAC

144

P. Scharrer, W.A. Barth, Ch.E. Düllmann, J. Khuyagbaatar
HIM, Mainz, Germany
W.A. Barth, M. Bevcic, Ch.E. Düllmann, L. Groening, K.P. Horn, E. Jäger, J. Khuyagbaatar, J. Krier, P. Scharrer, A. Yakushev
GSI, Darmstadt, Germany
Ch.E. Düllmann, P. Scharrer
Mainz University, Mainz, Germany

The GSI UNILAC in combination with SIS18 will serve as a high-current, heavy-ion injector for the future FAIR. It has to meet high demands in terms of beam brilliance at a low duty factor (100 mus beam pulse length, 2.7 Hz repetition rate). An advanced 1.4 MeV/u gas stripper setup has been developed, aiming at an enhanced yield into the required charge states. The setup delivers short, high-density gas pulses in synchronization with the beam pulse. This provides an increased gas density at a reduced gas load for the differential pumping system. In recent measurements, high-intensity, heavy-ion beams of U⁴⁺ were successfully stripped and separated for the desired charge state. The modified stripper setup, as well as major results, are presented, including a comparison to the present gas stripper based on a N₂ gas-jet. The stripping efficiency into the desired 28⁺ charge state was significantly increased by up to 60 % using a hydrogen stripper target while the beam quality remained similar.

Slides TUA1C01 [2.035 MB]

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)