A DEDICATED 70 MEV PROTON LINAC FOR THE ANTIPROTON PHYSICS PROGRAM OF THE FUTURE FACILITY FOR ANTIPROTON AND ION RESEARCH (FAIR) AT DARMSTADT

The antiproton physics program of the proposed International Accelerator Facility at Darmstadt is based on a rate of 7·10 10 cooled antiprotons per hour. To provide the primary proton intensities a proton linac is planned, which will be operated independently from the existing UNILAC for heavy ions. The proposed linac comprises a proton source, a RFQ, and a DTL. Its operation frequency of 352 MHz allows for an efficient acceleration to up to 70 MeV using normal conducting Crossed-bar H-cavities. These CH-cavities show high shunt impedances as known from IH-structures, but allow for much higher relative particle velocities of up to 50 %. The beam pulses with a length of at least 25 µs, a current of 70 mA, and total normalized transverse emittances of 2.8 µm will allow to fill the existing synchrotron SIS within one multi-turninjection up to its space charge limit of 7·10 12 protons. The maximum SIS ramping rate limits the applied proton linac repetition rate to 4 Hz. This paper gives an overview of the proposed proton linac. The status of the design including beam dynamic studies will be reported. We acknowledge the support of the European CommunityResearch Infrastructure Activity under the FP6 “Structuring the European Research Area” programme (CARE, contract number RII3-CT-2003-506395).