Charge collection and radiation hardness of a SOI microdosimeter for medical and space applications

Abstract

The first results obtained using a SO1 device for microdosimetry applications are presented. Microbeam and broadbeam spectroscopy methods are used for determining minority carrier lifetime and radiation damage constants. A spectroscopy model is presented which includes the majority of effects that impact spectral resolution. Charge collection statistics were found to substantially affect spectral resolution. Lateral diffusion effects significantly complicate charge collection.

Solid State Microdosimetry With Heavy Ions for Space Applications

“…In this case the mean chord length was governed mainly by central part of N+ region 10 10 m and applied bias, which determines the charge collection efficiency (CCE or ) in the lateral dimensions of the SV [25]. Increasing the geometrical size of SOI SV to 100 100 m (from the more typically used 30 30 m ) does not essentially change the mean chord length, as any increase in size is offset by a proportional reduction in average CCE.…”

A computational technique for simulating ionization energy deposition by energetic ions in complex targets

“…The charge collection efficiency as a function of position in the SOI device was determined using ion microprobe and alpha beam spectroscopy as previously reported [2], [5]. It was found that there was a small variation in charge collection efficiency of the diodes from regions nearest the diode junction (0.86) to regions furthest (0.79) the junction.…”

“…As previously reported [2], [3], [5], the SOI microdosimeter consists of an array of reversed biased, p-n junctions as illustrated in Figs. 1 and 2.…”

“…There are however several disadvantages in measuring lineal energy spectra with TEPC's [1]. A number of these have been overcome by using reversed biased, silicon-on-insulator diode arrays with microscopic sensitive volumes as microdosimeters [2]- [5]. Silicon microdosimetry studies using SOI devices in radiation oncology have been reported previously [2]- [5].…”

“…A number of these have been overcome by using reversed biased, silicon-on-insulator diode arrays with microscopic sensitive volumes as microdosimeters [2]- [5]. Silicon microdosimetry studies using SOI devices in radiation oncology have been reported previously [2]- [5]. In these studies, silicon microdosimeters were used to measure lineal energy spectra in such radiation oncology modalities as boron-neutron capture therapy (BNCT) [3], [4] and Proton therapy [2].…”