LINAC2014 - List of Authors (Schlitt, B.)

Paper	Title	Page
MOPP060	Status of the GSI Poststripper - HE-Linac	190
	S. Mickat, W.A. Barth, G. Clemente, X. Du, L. Groening, A. Orzhekhovskaya, B. Schlitt, H. Vormann, C. Xiao, S.G. Yaramyshev GSI, Darmstadt, Germany M. Droba, H. Hähnel, U. Ratzinger, R. Tiede IAP, Frankfurt am Main, Germany
	The High-Energy (HE) Linac is proposed to substitute the existing UNILAC post-stripper section. The post-stripper is an Alvarez DTL, which is in operation over four decades successfully. A quasi Front-to-End simulation along the UNILAC shows, that by taking future upgrade options into account already, with the existing Alvarez section the Fair requirements are not reached. Even by substituting the Alvarez section by the HE Linac the aim is not reached per se regarding the existing boundary conditions. Currently workpackages are defined together with the Institute of Applied Physics at Frankfurt University. Starting from the Ion sources to the SIS18 transfer channel every section is reinvestigated for improvements in beam quality and intensity.

TUPP058	RF System Development for the New 10⁸ MHz Heavy Ion High-Energy Linac at GSI	556
	B. Schlitt, M. Hoerr, A. Schnase, G. Schreiber, W. Vinzenz GSI, Darmstadt, Germany
	The GSI UNILAC is in operation successfully since about 40 years. A replacement of the post stripper section is proposed to provide heavy ion beams for the future FAIR facility. Design studies for a new 10⁸ MHz high-energy (HE) linac optimized to accelerate high brilliance and high current ion beams up to U²⁸⁺ for synchrotron injection are in progress. Thus, the UNILAC will be converted into a short-pulse accelerator, the RF duty cycle being reduced from around 30 % to <2 %. To feed the future HE linac and to prepare for the FAIR commissioning, a major modernisation of the existing post stripper RF systems is planned from 2015 to 2017. Besides, the development of a new 1.8 MW cavity amplifier prototype was started recently, based on the widely-used THALES tetrode TH558SC promising an availability for at least 25 years. New 120 - 150 kW solid state driver amplifiers will replace the existing tube drivers. A digital LLRF system designed by industry was integrated into an existing amplifier driving a single gap resonator and was tested including ion beam tests. An overview of the RF system design and of the planned upgrades will be reported including some results of the LLRF tests.

TUPP059	Advanced Beam Matching to a High Current RFQ	559
	S.G. Yaramyshev, W.A. Barth, L.A. Dahl, P. Gerhard, L. Groening, M.T. Maier, S. Mickat, A. Orzhekhovskaya, B. Schlitt, H. Vormann GSI, Darmstadt, Germany
	The High Current Injector (HSI) of the heavy ion linac UNILAC at GSI comprises the transport lines, the RFQ and two DTL tanks. Beam matching to the RFQ acceptance with a magnetic quadrupole quartet has been worked out manually during commissioning and operation of the machine. Due to a strong overlapping of the field from neighboring quadrupole lenses, a standard optics calculation does not provide for the required reliability. Advanced beam dynamics simulations have been done with the macroparticle code DYNAMION. The superposition of the measured magnetic fields of each quadrupole was taken into account. The quadrupole settings were optimized using the Monte-Carlo method. Two solutions have been found in accordance with the general theory of particle optics. Beam dynamics simulations with new quadrupole settings show an increased particle transmission through the RFQ. The results of numerical study have been confirmed during experimental campaigns. An improved performance of the whole HSI has been demonstrated. The proposed algorithm and a comparison of the measured data with result of simulations are presented.

Paper

Title

Page

Status of the GSI Poststripper - HE-Linac

190

S. Mickat, W.A. Barth, G. Clemente, X. Du, L. Groening, A. Orzhekhovskaya, B. Schlitt, H. Vormann, C. Xiao, S.G. Yaramyshev
GSI, Darmstadt, Germany
M. Droba, H. Hähnel, U. Ratzinger, R. Tiede
IAP, Frankfurt am Main, Germany

The High-Energy (HE) Linac is proposed to substitute the existing UNILAC post-stripper section. The post-stripper is an Alvarez DTL, which is in operation over four decades successfully. A quasi Front-to-End simulation along the UNILAC shows, that by taking future upgrade options into account already, with the existing Alvarez section the Fair requirements are not reached. Even by substituting the Alvarez section by the HE Linac the aim is not reached per se regarding the existing boundary conditions. Currently workpackages are defined together with the Institute of Applied Physics at Frankfurt University. Starting from the Ion sources to the SIS18 transfer channel every section is reinvestigated for improvements in beam quality and intensity.

TUPP058

RF System Development for the New 10⁸ MHz Heavy Ion High-Energy Linac at GSI

556

B. Schlitt, M. Hoerr, A. Schnase, G. Schreiber, W. Vinzenz
GSI, Darmstadt, Germany

The GSI UNILAC is in operation successfully since about 40 years. A replacement of the post stripper section is proposed to provide heavy ion beams for the future FAIR facility. Design studies for a new 10⁸ MHz high-energy (HE) linac optimized to accelerate high brilliance and high current ion beams up to U²⁸⁺ for synchrotron injection are in progress. Thus, the UNILAC will be converted into a short-pulse accelerator, the RF duty cycle being reduced from around 30 % to <2 %. To feed the future HE linac and to prepare for the FAIR commissioning, a major modernisation of the existing post stripper RF systems is planned from 2015 to 2017. Besides, the development of a new 1.8 MW cavity amplifier prototype was started recently, based on the widely-used THALES tetrode TH558SC promising an availability for at least 25 years. New 120 - 150 kW solid state driver amplifiers will replace the existing tube drivers. A digital LLRF system designed by industry was integrated into an existing amplifier driving a single gap resonator and was tested including ion beam tests. An overview of the RF system design and of the planned upgrades will be reported including some results of the LLRF tests.

TUPP059

Advanced Beam Matching to a High Current RFQ

559

S.G. Yaramyshev, W.A. Barth, L.A. Dahl, P. Gerhard, L. Groening, M.T. Maier, S. Mickat, A. Orzhekhovskaya, B. Schlitt, H. Vormann
GSI, Darmstadt, Germany

The High Current Injector (HSI) of the heavy ion linac UNILAC at GSI comprises the transport lines, the RFQ and two DTL tanks. Beam matching to the RFQ acceptance with a magnetic quadrupole quartet has been worked out manually during commissioning and operation of the machine. Due to a strong overlapping of the field from neighboring quadrupole lenses, a standard optics calculation does not provide for the required reliability. Advanced beam dynamics simulations have been done with the macroparticle code DYNAMION. The superposition of the measured magnetic fields of each quadrupole was taken into account. The quadrupole settings were optimized using the Monte-Carlo method. Two solutions have been found in accordance with the general theory of particle optics. Beam dynamics simulations with new quadrupole settings show an increased particle transmission through the RFQ. The results of numerical study have been confirmed during experimental campaigns. An improved performance of the whole HSI has been demonstrated. The proposed algorithm and a comparison of the measured data with result of simulations are presented.