KONUS BEAM DYNAMICS DESIGN OF A 70 mA , 70 MeV PROTON CH - DTL FOR GSI - SIS 12 *

Abstract The future scientific program at GSI needs a dedicated proton injector into the synchrotron SIS, in order to increase the proton intensity of the existing UNILAC/SIS12 combination by a factor of 70, resulting in 7x1012 protons in the synchrotron. A compact and efficient 352 MHz RFQ CH-DTL combination based on novel structure developments for RFQ and DTL was worked out. For DTL's operated in an H-mode like CHcavities (H210-mode), the shunt impedance is optimized by use of the KONUS beam dynamics. Beam dynamics simulation results of the CH-DTL section, covering the energy range from 3 to 70 MeV, with emphasis on the low energy front end are presented. Optimization aims are the reduction of emittance growth, of beam losses and of capital costs, by making use of the high acceleration gradients and shunt impedance values provided by the Crossbar H-Type (CH) structure. In addition, the beam dynamics design of the overall DTL layout has to be matched to the power limits of the available 352 MHz power klystrons. The aim is to power each cavity by one klystron with a peak rf power of around 1 MW.The future scientific program at GSI needs a dedicated proton injector into the synchrotron SIS, in order to increase the proton intensity of the existing UNILAC/SIS12 combination by a factor of 70, resulting in 7x1012 protons in the synchrotron. A compact and efficient 352 MHz RFQ CH-DTL combination based on novel structure developments for RFQ and DTL was worked out. For DTL's operated in an H-mode like CHcavities (H210-mode), the shunt impedance is optimized by use of the KONUS beam dynamics. Beam dynamics simulation results of the CH-DTL section, covering the energy range from 3 to 70 MeV, with emphasis on the low energy front end are presented. Optimization aims are the reduction of emittance growth, of beam losses and of capital costs, by making use of the high acceleration gradients and shunt impedance values provided by the Crossbar H-Type (CH) structure. In addition, the beam dynamics design of the overall DTL layout has to be matched to the power limits of the available 352 MHz power klystrons. The aim is to power each cavity by one klystron with a peak rf power of around 1 MW. Contribution to the conference LINAC 04, Lübeck, Germany Work supported by the European Community-Research Infrastructure Activity under the FP6 “Structuring the European Research Area” programme (CARE, contract number RII3-CT2003-506395). KONUS BEAM DYNAMICS DESIGN OF A 70 mA, 70 MeV PROTON CH-DTL FOR GSI-SIS12* R. Tiede, G. Clemente, H. Podlech, U. Ratzinger, IAP, University of Frankfurt/Main, Germany, W. Barth, L. Groening, GSI, Darmstadt, Germany, Z. Li, IMP, Lanzhou, China, S. Minaev, ITEP, Moscow, Russia Abstract The future scientific program at GSI needs a dedicated proton injector into the synchrotron SIS, in order to increase the proton intensity of the existing UNILAC/SIS12 combination by a factor of 70, resulting in 7x10 protons in the synchrotron. A compact and efficient 352 MHz RFQ CH-DTL combination based on novel structure developments for RFQ and DTL was worked out. For DTL's operated in an H-mode like CHcavities (H210-mode), the shunt impedance is optimized by use of the KONUS beam dynamics. Beam dynamics simulation results of the CH-DTL section, covering the energy range from 3 to 70 MeV, with emphasis on the low energy front end are presented. Optimization aims are the reduction of emittance growth, of beam losses and of capital costs, by making use of the high acceleration gradients and shunt impedance values provided by the Crossbar H-Type (CH) structure. In addition, the beam dynamics design of the overall DTL layout has to be matched to the power limits of the available 352 MHz power klystrons. The aim is to power each cavity by one klystron with a peak rf power of around 1 MW.The future scientific program at GSI needs a dedicated proton injector into the synchrotron SIS, in order to increase the proton intensity of the existing UNILAC/SIS12 combination by a factor of 70, resulting in 7x10 protons in the synchrotron. A compact and efficient 352 MHz RFQ CH-DTL combination based on novel structure developments for RFQ and DTL was worked out. For DTL's operated in an H-mode like CHcavities (H210-mode), the shunt impedance is optimized by use of the KONUS beam dynamics. Beam dynamics simulation results of the CH-DTL section, covering the energy range from 3 to 70 MeV, with emphasis on the low energy front end are presented. Optimization aims are the reduction of emittance growth, of beam losses and of capital costs, by making use of the high acceleration gradients and shunt impedance values provided by the Crossbar H-Type (CH) structure. In addition, the beam dynamics design of the overall DTL layout has to be matched to the power limits of the available 352 MHz power klystrons. The aim is to power each cavity by one klystron with a peak rf power of around 1 MW. DESIGN CRITERIA AND PARAMETERS KONUS beam dynamics and H-mode cavities First investigations on proton beam acceleration with a CH-DTL were presented in ref. [1]. For the proposed GSI Proton Injector the KONUS beam dynamics (“Kombinierte Null Grad Struktur” – Combined 0° Structure [2]), together with the use of H-mode structures (“Crossbar H-Type” CH) are foreseen for the energy range from 3 to 70 MeV. The advantages of this concept are: • High accel. gradients (up to 6 MV/m) due to the high shunt impedance of the CH-DTL and the KONUS beam dynamics concept (“slim” drift tubes without integrated quadrupole lenses housed in each multi-cell cavity). • Simplified construction, maintenance and reduced number of components. • Reduction of project costs and overall linac size.