S. Seshadri, D.M. Cole, B. Hancock, P. Ringold, C. Peay, C.Wrigley, M. Bonati, M.G. Brown, M. Schubnell, G. Rahmer, D. Guzman, D. Figer, G. Tarle, R.M. Smith, and C. Bebek Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, University of Michigan, Ann Arbor, MI, Rochester Institute of Technology, Rochester, NY and Lawrence Berkeley National Laboratory, Berkeley, CA, Department of Physics MS 300-315, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA, USA 91109, Email: suresh.seshadri@jpl.nasa.gov; PH: (818)-354-8370

We compare a more complete characterization of the low temperature performance of a nominal 1.7um cut-off wavelength 1kx1k InGaAs (lattice-matched to an InP substrate) photodiode array against similar, 2kx2k HgCdTe imagers to assess the suitability of InGaAs FPA technology for scientific imaging applications. The data we present indicate that the low temperature performance of existing InGaAs detector technology is well behaved and comparable to those obtained for state-of-the-art HgCdTe imagers for many space astronomical applications. We also discuss key differences observed between imagers in the two material systems.

There are five bolometric detector arrays for the SPIRE instrument on board of the Herschel Space Observatory. Our first report (Nguyen et al., 2004) presented the measurement of the two spectroscopic detector arrays. In this paper, we report the performance of the remaining three units for the Photometer, including the photometric long, medium and short wavelength (PLW, PMW and PSW). We note that all five SPIRE detector arrays meet the requirement.

We present the results of a study of the performance of InGaAs detectors conducted for the SuperNova Acceleration Probe (SNAP) dark energy mission concept. Low temperature data from a nominal 1.7um cut-off wavelength 1kx1k InGaAs photodiode array, hybridized to a Rockwell H1RG multiplexer suggest that InGaAs detector performance is comparable to those of existing 1.7um cut-off HgCdTe arrays. Advances in 1.7um HgCdTe dark current and noise initiated by the SNAP detector research and development program makes it the baseline detector technology for SNAP. However, the results presented herein suggest that existing InGaAs technology is a suitable alternative for other future astronomy applications.

We report the performance of the flight bolometer arrays for the Spectral and Photometric Imaging REceiver (SPIRE) instrument to be on board of the Herschel Space Observatory (HSO). We describe the test setup for the flight Bolometric Detector Assembly (BDA) that allows the characterization of its performance, both dark and optical, in one instrument's cool down. We summarize the laboratory procedure to measure the basic bolometer parameters, optical response time, optical efficiency of bolometer and feedhorn, dark and optical noise, and the overall thermal conductance of the BDA unit. Finally, we present the test results obtained from the two flight units, Spectroscopic Long Wavelength (SLW) and Spectroscopic Short Wavelength (SSW).

The paper describes the design, operation, and performance of integrated CMOS imagers that withstand multi-megarad(Si) total dose of ionizing radiation. It reports test results from two imagers - one with on-chip integrated timing and control, and the other with a variety of pixel structures for parametrically investigating the effects of radiation on imager performance. The CMOS imager has been shown to respond only to ionizing radiation, and is able to withstand high proton fluence. Minimal change in imager performance is observed after being subjected to a proton fluence of 1.2x10(12) protons/cm(2). The imager also exhibits minimal change in optical response after being dosed with 1.5 Megarad(Si). The radiation-induced dark current is small (similar to few pA/cm(2)/krad), and is well-behaved over the entire dose range. No change in operating bias is needed either for operating the imager at low-temperature or after irradiation. The parametric test chip indicates that the LOCOS region plays a significant role in determining the total-dose-hardness of the pixel. Based on test results, most promising pixel structures for imaging under high radiation environments have been identified.

This paper gives the status of theoretical and experimental efforts at JPL in the development of environmentally robust (Radiation Hard and Radiation Tolerant), ultra-low power, high performance CMOS active pixel sensor (APS) imagers for star tracker/imager applications. The work explores the effect of imager performance on star position accuracy, specifically examining the performance of JPL designed APS imagers. Accuracy is estimated as a function of star magnitude for a nominal star tracker optical design. Using these APS sensors, which have wide dynamic range and no blooming, simultaneous imaging of widely differing star magnitudes during the same observation is possible. It is shown that prototype Rad Hard APS imagers already meet many next generation, star tracker/imager mission performance requirements when operated at reduced temperatures. These imagers also provide excellent performance at cryogenic operating temperatures appropriate to some anticipate flight missions. APS imagers with their high level of integration, on-chip timing and control, ultra-low power, and environmental robustness are excellent candidates for NASA's earth observing, interplanetary and deep space exploration missions.