JWST near infrared detectors: latest test results

Abstract

The James Webb Space Telescope, an infrared-optimized space telescope being developed by NASA for launch in 2013, will utilize cutting-edge detector technology in its investigation of fundamental questions in astrophysics. JWST's near infrared spectrograph, NIRSpec utilizes two 2048 x 2048 HdCdTe arrays with Sidecar ASIC readout electronics developed by Teledyne to provide spectral coverage from 0.6 microns to 5 microns. We present recent test and calibration results for the NIRSpec flight arrays as well as data processing routines for noise reduction and cosmic ray rejection.

Development of 13-μm cutoff HgCdTe detector arrays for astronomy

“…In addition to the instrumentation involving the LW10 arrays, NEOCam will also have a camera with lower cut-off wavelength arrays (5 µm) already developed for WISE and the James Webb Space Telescope. 11 To meet the requirements of the NEOCam project, TIS successfully increased the array format from 512×512 pixels to 2048×2048 pixels. The arrays have cut-off wavelengths of ∼ 10 µm, low read noise, high quantum efficiency (QE), and have operabilities (well depth of more than 44,000 e − and dark current less than 200 e − /s ) > 90% up to temperatures of 42 K, and have been proton irradiated and demonstrated the ability to withstand the cosmic ray radiation that they are expected to receive in space.…”

“…already developed for WISE and the James Webb Space Telescope. 11 To meet the requirements of the NEOCam project, TIS successfully increased the array format from 512×512 pixels to 2048×2048 pixels. The arrays have cut-off wavelengths of ∼ 10 µm, low read noise, high quantum efficiency (QE), and have operabilities (well depth of more than 44,000 e − and dark current less than 200 e − /s ) > 90% up to temperatures of 42 K, and have been proton…”

Development of sensitive long-wave infrared detector arrays for passively cooled space missions

“…That earlier work included characterization of high dark current pixels associated with various types of defects, and TIS has developed techniques to overcome these to a large extent. In the last decade, TIS has demonstrated extremely sensitive 5 μm cutoff HgCdTe detector arrays for WISE and JWST, 16,17 and many of the lessons learned in that development were also applicable to long wavelength HgCdTe array development. TIS grew HgCdTe wafers for the NEOCam detector array development program with two variations.…”

“…TIS's HAWAII-1RG (H1RG) readout integrated circuit (ROIC) technology was selected for NEOCam based on the readout family's heritage in spaceand ground-based astronomical applications, including WISE, 14 the Hubble space telescope's wide-field camera-3, 15 and the JWST. 16,17 The HAWAII arrays have demonstrated the low power dissipation needed to support passive cooling as well as the low noise performance required to detect faint, natural background-limited astronomical sources and the narrow range of actual detector biases needed for operation of longer-wave HgCdTe photodiodes with a source-follower per detector ROIC.…”