Thermal vacuum testing of Timepix3 detector

Abstract

The thermal dependence of semiconductor detectors is one of their critical properties. This paper presents the results of the Timepix3 detector thermal vacuum testing, with respect to the effects on its properties and sensitivity. The Timepix3 represents a new generation of Timepix chips of the Medipix family, and it is equipped with an event-based mode of detection allowing for simultaneous measurement of the position, time and energy of an incident particle. Due to their properties, Timepix3 detectors are very suitable for space applications. Given that this is a relatively new device, the influence of temperature is not described in detail yet, especially for space usage. The operation of the device in a broad range of temperatures is required (e.q. QB50 mission on LEO from −20̂C to +50̂C). Timepix detectors have been used already in space missions, e.g. VZLUSAT-1, LUCID and SATRAM missions. In space, thermal cycling of the detectors occurs and this results in measurement distortion because both the noise edge and energy spectra are affected by changes in temperature. The experiments were performed on a detector equipped with a 300 μm thick Si sensor. The detector was equalised under various thermal conditions in vacuum and subsequently exposed to several energies of X-ray radiation corresponding to the characteristic radiation of 5 elements in the energy range of 4–24 keV. The results of these tests improve the knowledge regarding the behaviour of the essential components of the detector under extreme conditions. This new information can be used to improve measurements and thus minimise external influences, for example, in space applications but also in other fields where temperature stabilisation of the detector is very difficult or energy-consuming.