Qualification of 0-60 mbar pressure transducers for the LHC HiLumi environment

Abstract The LHC HiLumi upgrade requires the procurement of 0-60 mbar absolute pressure sensors with an absolute accuracy of +/- 0.3 mbar and a radiation Total Integrated Dose (TID) that may reach 100 kGy. Such a low-pressure range is usually measured through the deformation of a relatively large diaphragm and the sole passive sensors commercially available use magnetic coupling for the measurement of the deformation. Additionally, ABB provided CERN with their low-pressure measuring cell that is based on a piezo resistive bridge measuring the diaphragm deformation. A radiation qualification test was performed with a gamma source targeting a 100 kGy TID. The sensors under test were a Valydine AP10 and an ABB passive pressure cell. The pressure sensors were attached to a leak-tight sealed cell, the cell temperature can be adjusted and therefore the pressure followed the law of ideal gases. The paper presents the radiation measurement set-up, the readout electronics located in a radiation-free location and the results of the irradiation.