HIE Isolde – General Presentation of MATHILDE

In the frame of the HIE-ISOLDE project a superconducting Linac will upgrade the energy and intensity of the REX ISOLDE facility at CERN. It will be made of 2 low β and 4 high β cryomodules. Each high β cryomodule houses five superconducting RF cavities and one superconducting solenoid (respectively 6 and 2 for the low β). Beam physics simulations show that the optimum linac working conditions are obtained with components aligned and monitored on the Nominal Beam Line within 0.3 mm for the cavities and 0.15 mm for the solenoids at one sigma level. The Monitoring and Alignment Tracking for HIE-ISOLDE (MATHILDE) system is based on opto electronic sensors, optical and mechanical elements partly exposed to high vacuum and cryogenic temperatures. This paper summarizes the MATHILDE studies and focuses on the viewport crossing, the MATHIS software, the newly designed HBCAM cameras and the retro-reflective targets based on high index glass properties.