Dernière mise à jour : mercredi 19 novembre 2014, par
Development of a CMOS pixel sensor for embedded space dosimeter with low weight and minimal power dissipation
Started in September 2010, defended 23 September 2014
Directors : Jérôme BAUDOT / Yann HU.
This thesis focuses on the development of a CMOS monolithic pixel sensor used for space ionizing particles identification and counting in high flux. A new concept for single particle identification is proposed in this study, which is based on the analysis of particle triggered clusters. To validate this new concept, a full size sensor including the sensitive pixel matrix, an analogue signal processing chain, a 3-bit analogue to digital converter, and a digital processing stage was designed in a 0.35 μm process. The sensor directly output particles flux information through 4 channels with a very low data rate (80 bps) and minimal power dissipation ( 100mW). Each channel represents particles with different species and energies. The highest measurable flux density is up to 108 particles/cm2/s (hits pile up < 5%). A reduced scale prototype was fabricated and tested with 3 types of radiation illumination (X-ray, electrons and infrared laser). All the results obtained validate the proposed new concept and a highly miniaturized space radiation monitor based on a single CMOS pixel sensor could be foreseen. The monitor could provide measurements of comparable or better quality than existing instruments, but at around an order of magnitude lower power consumption, mass and volume and a lower unit cost. Moreover, due to its high level and low data rate outputs, no signal treatment power aside the sensor is required which makes it especially attractive for small satellite application.
Keywords : Highly miniaturized space radiation monitor, CMOS pixel sensor (CPS), Application Specific Integrated Circuit (ASIC), Partical identification and counting.