Prediction of Leakage Current and Depletion Voltage in Silicon Detectors Under Extraterrestrial Radiation Conditions

A Grummer,S Seidel,M R Hoeferkamp

doi:10.3389/fphy.2021.617026

Abstract

Silicon detection is a mature technology for registering the passage of charged particles. At the same time it continues to evolve toward increasing radiation tolerance as well as precision and adaptability. For these reasons it is likely to remain a critical element of detection of systems associated with extraterrestrial exploration. Silicon sensor leakage current and depletion voltage depend on the integrated fluence received by the sensor and on its thermal history during and after the irradiation process. For minimal assumptions on shielding and hence on the particle energy spectrum, and using published data on Martian ground temperature, we predict the leakage current density and the depletion voltage, as a function of time, of silicon sensors in transit to and deployed continuously on the Mars surface for a duration of up to 28 Earth-years, for several sensor geometries and a worst-case temperature scenario.

Highlights

This article reports predictions of the silicon sensor bulk characteristics, leakage current density, and depletion voltage, under the conditions of temperature and radiation, at the Mars surface, over a period corresponding to approximately 28.2 Earth-years, combined with the conditions of temperature and radiation associated with transit from the Earth to Mars during a period of about 250 days
Particle radiation at the surface of Mars is measured by a suite of devices, including three silicon p-i-n diodes, in the Radiation Assessment Detector (RAD) on the Mars Space Laboratory [2]
The Cosmic Ray Telescope for the Effects of Radiation (CRaTER), an instrument on the Lunar Reconnaissance Orbiter spacecraft designed to characterize the lunar radiation environment, uses six silicon disks [3]; its records of intense solar energetic particle (SEP) are input to human organ dose projection code to assess risks to space travelers due to SEP exposure

Summary

Current and Depletion Voltage in Silicon Detectors Under Extraterrestrial

Silicon detection is a mature technology for registering the passage of charged particles. At the same time it continues to evolve toward increasing radiation tolerance as well as precision and adaptability. For these reasons it is likely to remain a critical element of detection of systems associated with extraterrestrial exploration. For minimal assumptions on shielding and on the particle energy spectrum, and using published data on Martian ground temperature, we predict the leakage current density and the depletion voltage, as a function of time, of silicon sensors in transit to and deployed continuously on the Mars surface for a duration of up to 28 Earth-years, for several sensor geometries and a worst-case temperature scenario

INTRODUCTION

Silicon Detectors Under Extraterrestrial Conditions

Findings

TR T exp