[13p-B12-1~18] 2.2 Detection systems

[13p-B12-7] [Young Scientist Presentation Award Speech] Development of ionized particle detector using an ultra-thin diamond membrane

〇Wataru Kada¹, Tomihiro Kamiya², Veljko Grilj³, Natko Skukan³, Ivan Sudic³, Michal Pomorski⁴, Takahiro Makino², Yushi Ando^1,2, Shinobu Onoda², Osamu Hanaizumi¹, Milko Jaksic³, Takeshi Ohshima² (1.Gunma Univ., 2.QST/Takasaki, 3.RBI, 4.CEA-LIST)

Keywords:diamond, transmission detector, Avalanche Effect

In this study, we have developed a charged particle detector using a single crystal diamond that is locally thinned, and its characteristics were evaluated. While excellent bio-compatibility and electrical properties are remarkable for diamond, temporal degradation effect of charge collection efficiency (polarization) was observed with conventional diamond based radiation detector under charged particle irradiation. To suppress polarization effect and in order to develop detectors with better radiation resistance, a membrane detector structure with partially etched region with thickness of several μm was introduced to diamond detector by reactive ion etching method. Compared to the existing single-crystal diamond charged particle detector, significant improvement and suppression of transient attenuation effect of irradiation resistance has been confirmed under beam irradiation. With the benefit of membrane design, it is possible to apply an electric field significantly higher than conventional saturation level and linear proportional amplification of charge pulse signals was observed during MeV particle measurement with much higher electrical filed of ±20 V/μm. These experimental results suggest that this membrane structure is considered to be optimal to the realization of diamond detector to maximize the excellent electrical characteristics of single crystal diamond.