Monitoring of Particle Count Rate and LET Variations With Pulse Stretching Inverters

• Published in: IEEE transactions on nuclear science 2021-08, Vol.68 (8), p.1772-1781
• Main Authors: Andjelkovic, Marko, Chen, Junchao, Simevski, Aleksandar, Schrape, Oliver, Krstic, Milos, Kraemer, Rolf
• Format: Article
• Language: English
• Subjects: Adaptive systems; Atmospheric measurements; CMOS; Detectors; Energetic particles; Energy transfer; Fault tolerance; Inverters; Linear energy transfer (LET); Monitoring; Multiprocessing; Particle detector; Particle measurements; Pulse duration; pulse stretching inverters; Radiation counters; Radiation detectors; Sensitivity; Sensors; SET pulsewidth distribution; single-event transient (SET) count rate; Stretching; Transistors; Variation
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2021.3076400

This study investigates the use of pulse stretching (skew-sized) inverters for monitoring the variation of count rate and linear energy transfer (LET) of energetic particles. The basic particle detector is a cascade of two pulse stretching inverters, and the required sensing area is obtained by connecting up to 12 two-inverter cells in parallel and employing the required number of parallel arrays. The incident particles are detected as single-event transients (SETs), whereby the SET count rate denotes the particle count rate, while the SET pulsewidth distribution depicts the LET variations. The advantage of the proposed solution is the possibility to sense the LET variations using fully digital processing logic. SPICE simulations conducted on IHP's 130-nm CMOS technology have shown that the SET pulsewidth varies by approximately 550 ps over the LET range from 1 to 100 MeV \cdot cm {}^{2} \cdot mg −1 . The proposed detector is intended for triggering the fault-tolerant mechanisms within a self-adaptive multiprocessing system employed in space. It can be implemented as a standalone detector or integrated in the same chip with the target system.