Performance of the Karlsruhe Superconducting Proton Linear Testaccelerator

The advantage of the superconducting solution for rf accelerators in comparison to a normal conducting version is the drastic reduction of rf power requirement and hence reduced operating cost due to the much lower rf power losses at a comparable or higher accelerating field. The Karlsruhe group is the only one which studied in detail the acceleration of protons with superconducting resonators. Over the past several years a superconducting proton testlinac as a model accelerator has been completed. A review of the testaccelerator operation is given. The aim has been reached to demonstrate the feasibility of acceleration of protons for both high and low velocities. An energy of 4.5 MeV with a beam current of 150 ¿A (100% duty cycle) was obtained and accelerator performance has been tested. This includes more than 1000 hours of high field operation of the superconducting resonators and more than 3000 hours operation of the cryogenic system. Energy gradients of 1 - 2 MeV/m have been obtained reproducibly over the past several years without any degradation and without additional surface treatments after installation of the resonators into the accelerator.