Radiation Hardness of the Siemens SIPART intelligent valve positioner

About 1400 Siemens SIPART PS2 intelligent valve positioners are installed in the LHC accelerator. They were selected assuming that their non-electronic parts are intrinsically radiation hard. This positioner variant is a split design: the electronic board located in a radiation protected area and the electro-pneumatic unit on the valve stem. The next LHC upgrade will result in a significant increase of the radiation levels and the initial radiation hardness assumption may not hold. A preliminary test on an electro-pneumatic unit was done with a cobalt 60 source. At the end of the test (99.8 kGy) one of the two miniature piezoelectric valves was damaged. After this result, the CERN CALLAB facility was used to irradiate 10 miniature piezoelectric valves while they were powered by an electrical signal. The first failures are observed after a dose of 137 kGy. The paper describes the test protocol and synthesizes the results.