학술논문

Comparison of Measured Dark Current Distributions With Calculated Damage Energy Distributions in HgCdTe
Document Type
Periodical
Source
IEEE Transactions on Nuclear Science IEEE Trans. Nucl. Sci. Nuclear Science, IEEE Transactions on. 54(4):1097-1103 Aug, 2007
Subject
Nuclear Engineering
Bioengineering
Current measurement
Energy measurement
Dark current
Sensor arrays
Monte Carlo methods
Extraterrestrial measurements
Protons
Kinematics
Infrared detectors
Telescopes
CCD
dark current distribution
GEANT4
HgCdTe
proton effects
Language
ISSN
0018-9499
1558-1578
Abstract
This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distributions were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described by Marshall The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Carlo code MCNPX) produce a pronounced skewing of the damage energy distribution. While the nuclear elastic component (also calculated using the MCNPX) contributes only a small fraction of the total nonionizing damage energy, its inclusion in the shape of the damage across the array is significant. The Coulombic contribution was calculated using the Monte Carlo radiative energy desposition (MRED), a Geant4 application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.