Misalignment and Error Studies of the High Energy Section of the HIE-ISOLDE Linac

The sensitivity of the beam to misalignment and error is investigated in order to specify design tolerances for the high energy section of the superconducting upgrade to the REXISOLDE linac. Alongside misalignment, the machine errors studied include error in the transverse Twiss parameters at injection, error in the solenoid fields, error in the beam position monitors, as well as fast and static errors in the phase and voltage of the cavities. The tolerances were specified by tracking a single particle representing the beam centroid in a matrix model of the linac, with the realistic fields parameterised in transfer matrices. The matrixmodel was verified using the TRACK code, which carries out the numerical integration of the equations of motion for multi-particle beams in the realistic fields.