PROPERTIES OF THE FRONT PART OF THE REX-ISOLDE LINAC*

Abstract The structures of the linear accelerator of the Radioactive beam Experiment (REX-ISOLDE) THE REX-ISOLDE TEST BEAM LINE Experimental Setup The test beam line at the accelerator laboratory at Garching has been built up to perform He 1+ beam experiments with the RFQ and the following matching section between RFQ and IH structure. Its injection system consisted of a duoplasmatron ion source, a prototype of the REX-ISOLDE diagnostic box and an electrostatic quadrupole quadruplet from the REX-ISOLDE mass separator. In a first stage, the emittance was measured behind the injection system, to check the quality of the beam and to compare the measured beam parameters to the COSY calculations for beam injection. In the following step, the test beam line was built up completely like shown in Beam Tests with the RFQ The tests with the REX-RFQ [4] were done to verify the design calculations concerning transmission, energy spread, bunch structure and output emittances of the accelerator. Further, the dependence of these parameters on the rf-power, beam current and input emittance has been measured. The transmission through the RFQ at different electrode voltages is plotted i