Transient radiation effects in ultra-low noise HgCdTe IR detector arrays for space-based astronomy

Abstract

We present measurements of proton-induced single event transients in ultra-low noise HgCdTe IR detector arrays being developed for space-based astronomy and compare to modeling results.Index Terms-HgCdTe, IR detectors, single event transients, space-based astronomy, transient noise.

Characterization of transient signal induced in IR detector array by Jupiter high-energy electrons and implications for JUICE/MAJIS operability

“…Given the incident distribution of electrons shown in Fig. 2, some of these electrons (those with a high penetration depth) will cross the shielding material and simply reach the FPA (Focal Plane Array) with an almost unchanged energy (Raftari et al, 2018), while some other electrons will loose some of their energy in the shielding material and generate secondary electrons (Pickel et al, 2005). The FPA consists of an HgCdTe layer, which has been grown on a removed CdZnTe substrate (see (Beletic et al, 2008)), linked to its Si ReadOut Integrated Circuit (ROIC) by In bump bonds.…”

“…During the integration time, each pixel in the HgCdTe layer has a high-field depletion area near the In bonds and a low-field diffusion area elsewhere, which allow for charge creation when a photon from the science targets hits the detector. However, when an energetic primary or secondary electron from the environment reaches this FPA, it will also generate charges along its path if its penetration depth is not too high, either in the depletion area which will be counted by the ROIC as additional signal in the hit pixel, or in the diffusion area in which case it may diffuse from the hit pixel to contiguous ones and be finally counted in another depletion area (see (Pickel et al, 2005)). This means that single electrons may generate several spikes in the shape of a cluster, especially if the incidence angle is high (Becker et al, 2005).…”

Evaluation of space radiation effects on HgCdTe avalanche photodiode arrays for Lidar applications

“…HgCdTe photodiode arrays have been tested for radiation damage and showed little impact from radiation damage expected for the JWST mission. [16][17][18][19][20][21][22][23] The only degradation found was a slight decrease in the responsivity and a slight increase in dark current. HgCdTe APD arrays are relative new and no data on the radiation damage are available at present.…”