AlphaRad, a new integrated CMOS System-on-Chip for high efficiency alpha particles counting

Abstract

An integrated System-on-Chip (SoC) has been designed in 0.6 \mu m CMOS mixed analog/digital technology, and tested for high rate alpha particle Counting. The sensor is the most innovative part of the chip, with a total active area of 2 x 2.5 mm x 5 mm. The two-stage charge-to-voltage amplification scheme includes a numerical block for offset compensation. Designed with a gain of 700, the chip has been tested in alpha sources: a very high signal over noise ratio was obtained, leading to a detection efficiency of 5 MeV alpha particles close to 100%. The chip is working at room temperature and has been tested tip to 300 kHz reset frequency. Future applications of this SoC will focus on detection of fast and thermal neutrons free of gamma contamination

Development of an integrated CMOS detector for radon activity measurement and neutron dosimetry

“…As the 2048 diodes are connected in parallel, a very fast detection cycle is possible, up to 300 kHz for the full area (2.5 × 5mm 2 ) with a negligible dead time. Thanks to a signal/noise ratio of 70, the measured efficiency [3] of the AlphaRad chip to 5 MeV α-particles is close to 100%. really needed for this application, the dedicated system-onchip AlphaRad [3] was designed with a larger sensitive area and a fully parallel readout with a single numeric output, allowing a fast reset cycle up to 300 kHz, a promising feature for neutron beam monitoring (see section 4).…”

“…Thanks to a signal/noise ratio of 70, the measured efficiency [3] of the AlphaRad chip to 5 MeV α-particles is close to 100%. really needed for this application, the dedicated system-onchip AlphaRad [3] was designed with a larger sensitive area and a fully parallel readout with a single numeric output, allowing a fast reset cycle up to 300 kHz, a promising feature for neutron beam monitoring (see section 4). For radon purposes, we present here a nearly complete device with several independent AlphaRad chips running in parallel on a portable board, ready for a fully standalone mode of operation.…”

“…In a fully passive counting mode, the device detects the total alpha-activity of the neutral 222 Rn plus its two daughters 218 Po and 214 Po. The system is already twenty times faster than a previously published experiment [3] based on CMOS pixels, and an excellent linearity has been demonstrated on a special test bench for high radon activities. The future Electronic Radon Monitor will include collection of the Po daughters, providing radon monitoring at low voltage conditions (5 V), long-term and standalone operation without any external PC.…”

Design of a monolithic CMOS sensor for high efficiency neutron counting

“…Compared to our previous design AlphaRad1 [17], the new prototype is able to detect recoil protons and a-particles at the single particle level thanks to its low noise.…”

R&D métrologie des rayonnements ionisants à l’IPHC : de l’application des détecteurs visuels aux mesures environnementales

“…Ce projet consiste à concevoir des capteurs CMOS pour la détection des neutrons et des particules alpha, pour en faire des dosimètres portatifs, notamment pour les mesures en continu de l'activité volumique du radon dans l'environnement atmosphérique. Des capteurs CMOS ont déjà été soumis à des tests de détection de particules α du radon et descendants (Nachab et al, 2004b ;Nourreddine et al, 2005 ;Husson et al, 2006) à l'aide d'une chaîne d'acquisition conçue pour cette application. Un nouveau dispositif pour la dosimétrie neutron multiplage est en cours de réalisation.…”