IPAC2016 - List of Authors (Zhang, C.)

Paper	Title	Page
MOPOY016	HSI RFQ Upgrade for the UNILAC Injection to FAIR	877
	C. Zhang, L. Groening, O.K. Kester, S. Mickat, H. Vormann GSI, Darmstadt, Germany M. Baschke, H. Podlech, U. Ratzinger, R. Tiede IAP, Frankfurt am Main, Germany
	As an injector to the future FAIR facility, the UNILAC accelerator is required to deliver ion beams with high intensities as well as good beam quality. The electrodes of the current HSI RFQ are exhausted and the current RFQ itself is assigned to be one bottle-neck for improving the brilliance performance of the whole linac. Based on the so-called NFSP (New Four-Section Procedure) method, a new RFQ electrode design has been developed and optimized for 20 emA, U⁴⁺ beams at the RFQ entrance. Since only the electrodes will be replaced, the RFQ length has been kept unchanged. Even with a lowered inter-vane voltage, the new RFQ design has achieved better beam performance compared to the previous design. This paper will focus on the performed study with respect to beam dynamics.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY016
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MOPOY017	Upgrade of the Universal Linear Accelerator UNILAC for FAIR	880
	L. Groening, A. Adonin, X. Du, R. Hollinger, E. Jäger, M.T. Maier, S. Mickat, A. Rubin, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao, A. Yakushev, C. Zhang GSI, Darmstadt, Germany M. Baschke, H. Hähnel, H. Podlech, U. Ratzinger, A. Seibel, R. Tiede IAP, Frankfurt am Main, Germany Ch.E. Düllmann, P. Scharrer HIM, Mainz, Germany
	In order to meet the requirements on beam parameters for the upcoming FAIR facility at GSI, the injector linac UNILAC will be upgraded. The activities comprise development of the sources for stable provision of intense uranium beams at a repetition rate of 2.7 Hz, a revision of the beam dynamics layout of the 120 keV/u RFQ, the replacement of the matching section to the 1.4 MeV/u pre-stripper DTL, and enhancement of the gaseous stripping section efficiency. This section shall also include a round-to-flat emittance adaptor to prepare the beam for injection into the synchrotron SIS18 which has a flat transverse injection acceptance. Finally, the upgrade includes the complete replacement of the 40 year old 11.4 MeV/u Alvarez-type post-stripper DTL with a new DTL, preferably using Alvarez-type cavities with improved beam focusing features, as well as its rf-power alimentations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY017
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MOPOY018	The New RF Design of the 36 MHz-HSI-RFQ at GSI	883
	M. Baschke, H. Podlech IAP, Frankfurt am Main, Germany L. Groening, S. Mickat, C. Zhang GSI, Darmstadt, Germany
	In Darmstadt / Germany the existing accelerator cite GSI is expanding to one of the biggest joint research projects worldwide: FAIR, a new antiproton and ion research facility with so far unmatched intensities and quality. The existing accelerators will be used as pre-accelerators and therefor need to be upgraded to fulfill the requirements with respect for intensity and beam quality. In a first step the 9.2 m long 36 MHz-HSI-RFQ for high current beams will get new electrodes to reach the specific frequency, to allow a higher electric strength and to avoid unwanted multipole components. Therefor several simulations with CST MWS have been done. The parameters and results of the RF-design will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY018
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MOPOY024	Development of a 325 MHz Ladder-RFQ of the 4-Rod-Type	899
	M. Schütt, U. Ratzinger IAP, Frankfurt am Main, Germany C. Zhang GSI, Darmstadt, Germany
	In order to have an inexpensive alternative to 4-Vane RFQs above 200 MHz, we study the possibilities of a Ladder-RFQ. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the research program with cooled antiprotons at FAIR. This particular high frequency for an RFQ creates difficulties, which are challenging in developing a cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with a ladder type RFQ, which has been investigated since 2013. Due to its geometric size the manufacturing as well as maintenance is not that complex compared with welded accelerators. The manufacturing, coppering and assembling of a 0.8 m prototype RFQ is finished. We present recent measurements of the rf-field, frequency-tuning, field flatness and the mode spectrum.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY024
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Paper

Title

Page

HSI RFQ Upgrade for the UNILAC Injection to FAIR

877

C. Zhang, L. Groening, O.K. Kester, S. Mickat, H. Vormann
GSI, Darmstadt, Germany
M. Baschke, H. Podlech, U. Ratzinger, R. Tiede
IAP, Frankfurt am Main, Germany

As an injector to the future FAIR facility, the UNILAC accelerator is required to deliver ion beams with high intensities as well as good beam quality. The electrodes of the current HSI RFQ are exhausted and the current RFQ itself is assigned to be one bottle-neck for improving the brilliance performance of the whole linac. Based on the so-called NFSP (New Four-Section Procedure) method, a new RFQ electrode design has been developed and optimized for 20 emA, U⁴⁺ beams at the RFQ entrance. Since only the electrodes will be replaced, the RFQ length has been kept unchanged. Even with a lowered inter-vane voltage, the new RFQ design has achieved better beam performance compared to the previous design. This paper will focus on the performed study with respect to beam dynamics.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY016

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MOPOY017

Upgrade of the Universal Linear Accelerator UNILAC for FAIR

880

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

In order to meet the requirements on beam parameters for the upcoming FAIR facility at GSI, the injector linac UNILAC will be upgraded. The activities comprise development of the sources for stable provision of intense uranium beams at a repetition rate of 2.7 Hz, a revision of the beam dynamics layout of the 120 keV/u RFQ, the replacement of the matching section to the 1.4 MeV/u pre-stripper DTL, and enhancement of the gaseous stripping section efficiency. This section shall also include a round-to-flat emittance adaptor to prepare the beam for injection into the synchrotron SIS18 which has a flat transverse injection acceptance. Finally, the upgrade includes the complete replacement of the 40 year old 11.4 MeV/u Alvarez-type post-stripper DTL with a new DTL, preferably using Alvarez-type cavities with improved beam focusing features, as well as its rf-power alimentations.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY017

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MOPOY018

The New RF Design of the 36 MHz-HSI-RFQ at GSI

883

M. Baschke, H. Podlech
IAP, Frankfurt am Main, Germany
L. Groening, S. Mickat, C. Zhang
GSI, Darmstadt, Germany

In Darmstadt / Germany the existing accelerator cite GSI is expanding to one of the biggest joint research projects worldwide: FAIR, a new antiproton and ion research facility with so far unmatched intensities and quality. The existing accelerators will be used as pre-accelerators and therefor need to be upgraded to fulfill the requirements with respect for intensity and beam quality. In a first step the 9.2 m long 36 MHz-HSI-RFQ for high current beams will get new electrodes to reach the specific frequency, to allow a higher electric strength and to avoid unwanted multipole components. Therefor several simulations with CST MWS have been done. The parameters and results of the RF-design will be presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY018

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOY024

Development of a 325 MHz Ladder-RFQ of the 4-Rod-Type

899

M. Schütt, U. Ratzinger
IAP, Frankfurt am Main, Germany
C. Zhang
GSI, Darmstadt, Germany

In order to have an inexpensive alternative to 4-Vane RFQs above 200 MHz, we study the possibilities of a Ladder-RFQ. The 325 MHz RFQ is designed to accelerate protons from 95 keV to 3.0 MeV according to the design parameters of the research program with cooled antiprotons at FAIR. This particular high frequency for an RFQ creates difficulties, which are challenging in developing a cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with a ladder type RFQ, which has been investigated since 2013. Due to its geometric size the manufacturing as well as maintenance is not that complex compared with welded accelerators. The manufacturing, coppering and assembling of a 0.8 m prototype RFQ is finished. We present recent measurements of the rf-field, frequency-tuning, field flatness and the mode spectrum.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY024

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