Test Measurements with the REX-ISOLDE LINAC Structures

The Radioactive Beam Experiment {REX-ISOLDE} [1,2] is a pilot experiment at ISOLDE (CERN) testing the new concept of post acceleration of radioactive ion beams by using charge breeding of the ions in a high charge state ion source and the efficient acceleration of the highly charged ions in a short LINAC using modern ion accelerator structures. In order to prepare the ions for the experiments singly charged radioactive ions from the on-line mass separator ISOLDE will be cooled and bunched in a Penning trap, charge bred in an electron beam ion source (EBIS) and finally accelerated in the LINAC. The LINAC consists of a radio frequency quadrupole (RFQ) accelerator, which accelerates the ions up to 0.3 MeV/u, an 20 gap interdigital H-type (IH) structure with a final energy between 1.1 and 1.2 MeV/u and three seven gap resonators, which allow the variation of the final energy between 0.8-2.2 MeV/u. A variety of tests with REXTRAP, REXEBIS and the LINAC structures have been done, in order to study their capabilities. An emittance meter for beam intensities down to 0.5 nA and a test beam line for the front part of the REX-ISOLDE LINAC have been built up in order to measure beam emittances of the different components of REX-ISOLDE and beam energy, energy spread and transmission of the LINAC structures. The results of these measurements and the first tests at CERN will be presented.