Peter Hülsmann, GSI RF-Group, Tel: Task SIS18-1: h=2 Cavity P. Hülsmann GSI, Gesellschaft für Schwerionenforschung mbH Planckstraße 1 D Darmstadt EU-FP6 Kick Off Meeting, December 1 - 2, 2005

Peter Hülsmann, GSI RF-Group, Tel: Task SIS18-1: h=2 Cavity 1)Present Status 2)Technical Description 3)Organizational Issues 4)Time Schedule 5)General Strategy for Construction 6)Cost Overview Content

Peter Hülsmann, GSI RF-Group, Tel: Objectives Development of new RF accelerating cavity based on the novel magnetic alloy materials (MA-materials) for operation at harmonic number h=2 (f = 0.43 to 2.5 MHZ) to provide the necessary accelerating voltage for SIS18 injector operation with high intensity heavy ion beams in a fast operation mode with four cycles per second. Additional Information Presently the SIS18 rf – system operates at the fourth harmonic. At the end of the SIS18 upgrade program the harmonic number two system will replace one of the old cavities in order to enable a double harmonic rf operation with the remaining cavity. It is important to point out that the existing SIS18 rf system does not provide enough bucket area in order to accelerate intense bunches in the 4 Hz SIS12 mode. 1) Present Status Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: Boundary conditions for the h=2 rf system Due to the many insertions which were additionally implemented into the synchrotron ring SIS12/18 in the meantime, the available length in SIS12/18 for one cavity is very short. Thus, the priority objective is a cavity which has a length of not more than 2 m. The gap voltage requirement with space charge effects but without beam loading is 40 kV in the frequency region of 0,429-1,168 MHz. In order to leave a safety margin we demand a total voltage of not less than 50 kV. If an ordinary ferrite is used for the cavity the total length would be more than 5 m. 1) Present Status Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: ) Technical Description: The rf-system Technical Subsystems Cavity Consists of two independent units with two gaps each The two gaps of a unit are connected in parallel Cavity is filled with a total of 24 magnetic alloy ring cores The ring cores are directly cooled by silicon oil Power amplifier One push pull amplifier for each unit One amplifier consists of two 300 kW RS 2042 SK tubes One amplifier delivers 180 kW rf output power Supply unit Low Level RF and PLC Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: Table 1: Geometical data to the Finemet FT-3M ring cores Inner radius ri150 mm Outer radius ra475 mm Ring core hight h35 mm Surface for cooling2 x 0,64 m 2 Table 2: The cavity Number of ceramic gaps4 Number of ring cores per halfcavity3 Number of ring cores in both units24 Overall surface of all ring cores31 m 2 2) Technical Description: Cavity Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: Personnel Task Leader GSI: P. Hülsmann Posts at GSI 1 new Scientist (advertisement for post not yet completed) 1 new Engineer (contract start ) 108 person-months 1.12 M€ investments 3) Organisational Issues Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: ) Schedule (Description of Work) Personnel not yet available Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: Task SIS18-1: h=2 Cavity 5) General strategy for construction Subsystems to be purchased by industrial companies or institutes Main focus on system integration Risks Organisational risks Staffing (delayed hiring, adjustment to new job) Tough time schedule due to FAIR-overall planning Technical risks Extraordinary technical requirements Reliability

Peter Hülsmann, GSI RF-Group, Tel: ) Cost Overview No collaboration partner for this task (CERN has withdrawn its participation because of manpower problems) Task SIS18-1: h=2 Cavity

Peter Hülsmann, GSI RF-Group, Tel: SIS18 h=2 MA-Broadband-RF-System for Acceleration (Duty Cycle 50% => directly cooled, 13 kW / Ring Core) ParametersContinous operation Frequency (MHz)0,4 – 2,5 Gap-Voltage (kV)40 Duty Cycle50% Total Power (kW)600 SIS18 h=2 acceleration: cost estimatons per unit SystemAdditional Information Costs [k€] Cavity (broadband => no bias current) Number of MA-Cores=24, four Gaps, two are connected in parallel, no bias windings 280 Power Amplifier P RFout =360 kW, P AD =900 kW Tube=4 x RS 2042 SK (300 kW) 300 Supply Unit U A =8,3 kV, I Amax =65 A U G2 =1,5 kV, P Th =6 kW 360 Driver Amplifier2 x 2 kW (0,4-2,5 MHz)60 LLRF90 Cabling, Accessories 30 Sum1120 EU FP6 construction -> non-commercial, reduced price