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Journal ArticleDOI

Cryogenic capacitive transimpedance amplifier for astronomical infrared detectors

TL;DR: In this article, a capacitive transimpedance amplifier (CTIA) was developed to operate at 2 K and have good performance as readout circuits of astronomical far-infrared array detectors.
Abstract: We have developed a new capacitive transimpedance amplifier (CTIA) that can be operated at 2 K, and have good performance as readout circuits of astronomical far-infrared array detectors. The circuit design of the present CTIA consists of silicon p-MOSFETs and other passive elements. The process is a standard Bi-CMOS process with 0.5 /spl mu/m design rule. The open-loop gain of the CTIA is more than 300, resulting in good integration performance. The output voltage swing of the CTIA was 270 mV. The power consumption for each CTIA is less than 10 /spl mu/W. The noise at the output showed a 1/f noise spectrum of 4 /spl mu/V//spl radic/Hz at 1 Hz. The performance of this CTIA nearly fulfills the requirements for the far-infrared array detectors onboard ASTRO-F, Japanese infrared astronomical satellite to be launched in 2005.
Citations
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Journal ArticleDOI
TL;DR: The Far-Infrared Surveyor (FIS) is one of two focal-plane instruments on the AKARI satellite as discussed by the authors, which has four photometric bands at 65, 90, 140, and 160 mu m and uses two kinds of array detectors.
Abstract: The Far-Infrared Surveyor (FIS) is one of two focal-plane instruments on the AKARI satellite. FIS has four photometric bands at 65, 90, 140, and 160 mu m, and uses two kinds of array detectors. The FIS arrays and optics are designed to sweep the sky with high spatial resolution and redundancy. The actual scan width is more than eight arcminutes, and the pixel pitch matches the diffraction limit of the telescope. Derived point-spread functions (PSFs) from observations of asteroids are similar to those given by the optical model. Significant excesses, however, are clearly seen around tails of the PSFs, whose contributions are about 30% of the total power. All FIS functions are operating well in orbit, and the performance meets the laboratory characterizations, except for the two longer wavelength bands, which are not performing as well as characterized. Furthermore, the FIS has a spectroscopic capability using a Fourier transform spectrometer (FTS). Because the FTS takes advantage of the optics and detectors of the photometer, it can simultaneously make a spectral map. This paper summarizes the in-flight technical and operational performance of the FIS.

291 citations

Journal ArticleDOI
TL;DR: A far-infrared all-sky atlas from the Japanese AKARI satellite is presented in this article, which covers >99% of the sky in four photometric bands centred at 65, 90, 120, 140, and 160 μm, with spatial resolutions ranging from 1' to 1'5.
Abstract: We present a far-infrared all-sky atlas from a sensitive all-sky survey using the Japanese AKARI satellite. The survey covers >99% of the sky in four photometric bands centred at 65 μm, 90 μm, 140 μm, and 160 μm, with spatial resolutions ranging from 1' to 1".5. These data provide crucial information on the investigation and characterisation of the properties of dusty material in the interstellar medium (ISM), since a significant portion of itsenergy is emitted between ∼ 50 and 200μm. The large-scale distribution of interstellar clouds, their thermal dust temperatures, and their column densities can be investigated with the improved spatial resolution compared to earlier all-sky survey observations. In addition to the point source distribution, the large-scale distribution of ISM cirrus emission, and its filamentary structure, are well traced. We have made the first public release of the full-sky data to provide a legacy data set for use in the astronomical community

117 citations

Journal ArticleDOI
TL;DR: A far-infrared atlas from a sensitive all-sky survey using the Japanese $AKARI$ satellite is presented in this paper, which provides crucial information for the investigation and characterisation of the properties of dusty material in the Interstellar Medium (ISM), since significant portion of its energy is emitted between ∼$50 and 200 µm.
Abstract: We present a far-infrared all-sky atlas from a sensitive all-sky survey using the Japanese $AKARI$ satellite. The survey covers $> 99$% of the sky in four photometric bands centred at 65 $\mu$m, 90 $\mu$m, 140 $\mu$m, and 160 $\mu$m with spatial resolutions ranging from 1 to 1.5 arcmin. These data provide crucial information for the investigation and characterisation of the properties of dusty material in the Interstellar Medium (ISM), since significant portion of its energy is emitted between $\sim$50 and 200 $\mu$m. The large-scale distribution of interstellar clouds, their thermal dust temperatures and column densities, can be investigated with the improved spatial resolution compared to earlier all-sky survey observations. In addition to the point source distribution, the large-scale distribution of ISM cirrus emission, and its filamentary structure, are well traced. We have made the first public release of the full-sky data to provide a legacy data set for use by the astronomical community.

105 citations

Posted Content
TL;DR: The FIR AKARI full-sky maps provide a rich new data set within which astronomers can investigate the distribution of interstellar matter throughout our Galaxy, and beyond as discussed by the authors, and the high Galactic latitude sky is shown to be covered with a diffuse filamentary web of dusty emission that traces the potential sites of high latitude star formation.
Abstract: Far-infrared observations provide crucial data for the investigation and characterisation of the properties of dusty material in the Interstellar Medium (ISM), since most of its energy is emitted between ~100 and 200 um. We present the first all-sky image from a sensitive all-sky survey using the Japanese AKARI satellite, in the wavelength range 50 -- 180 um. Covering >99% of the sky in four photometric bands with four filters centred at 65 um, 90 um, 140 um, and 160 um wavelengths, this achieved spatial resolutions from 1 to 2 arcmin and a detection limit of <10 MJy sr-1, with absolute and relative photometric accuracies of <20%. All-sky images of the Galactic dust continuum emission enable astronomers to map the large-scale distribution of the diffuse ISM cirrus, to study its thermal dust temperature, emissivity and column density, and to measure the interaction of the Galactic radiation field and embedded objects with the surrounding ISM. In addition to the point source population of stars, protostars, star-forming regions, and galaxies, the high Galactic latitude sky is shown to be covered with a diffuse filamentary-web of dusty emission that traces the potential sites of high latitude star formation. We show that the temperature of dust particles in thermal equilibrium with the ambient interstellar radiation field can be estimated by using 90 um, 140 um, and 160 um data. The FIR AKARI full-sky maps provide a rich new data set within which astronomers can investigate the distribution of interstellar matter throughout our Galaxy, and beyond.

55 citations

Journal ArticleDOI
TL;DR: In this article, the characterization and calibration of the Slow-Scan observation mode of the FIS onboard the AKARI satellite is presented and the derived full widths at the half maximum (FWHMs) are �30 ′′ for the two shorter wavelength bands and �40 ¼′ for two longer wavelength bands, being consistent with those obtained by the All-Sky Survey.
Abstract: We present the characterization and calibration of the Slow-Scan observation mode of the Far-Infrared Surveyor (FIS) onboard the AKARI satellite. The FIS, one of the two focal-plane instruments on AKARI, has four photometric bands between 50– 180 µm with two types of Ge:Ga array detectors. In addition to the All-Sky Survey, FIS has also taken detailed far-infrared images of selected targets by using the SlowScan mode. The sensitivity of the Slow-Scan mode is one to two orders of magnitude better than that of the All-Sky Survey, because the exposure time on a targeted source is much longer. The point spread functions (PSFs) were obtained by observing several bright point-like objects such as asteroids, stars, and galaxies. The derived full widths at the half maximum (FWHMs) are �30 ′′ for the two shorter wavelength bands and �40 ′′ for the two longer wavelength bands, being consistent with those

45 citations

References
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01 Jan 2003

3,254 citations

Journal ArticleDOI
TL;DR: In this article, the phenomenon of and the physical mechanisms for the generation of minority carriers in the substrate of NMOS and CMOS are studied and a theoretical model based on the lucky electron concept and the bremsstrahlung mechanism is proposed.
Abstract: The phenomenon of and the physical mechanisms for the generation of minority carriers in the substrate of NMOS and CMOS are studied Secondary impact ionization is not responsible The responsible mechanisms are hot-electron-induced photocarrier generation and, under extreme conditions, forward biasing of the source-substrate junction The photon generation is believed to be due to the bremsstrahlung of the channel hot electrons A theoretical model based on the lucky electron concept and the bremsstrahlung mechanism is proposed The calculated characteristics of photon generation agree well with experimental results About 2 × 10-5photogenerated minority carriers are generated for every (primary) impact-ionization event in NMOSFET Photocarrier-induced leakage current can be fitted with either an inverse square dependence on distance or an exponential dependence with an effective decay length of about 780 µm

295 citations

Journal ArticleDOI
TL;DR: The European Space Agency's (ESA) Infrared Space Observatory (ISO) as mentioned in this paper was the first true orbiting infrared observatory, which was launched by Ariane in November 1995 and provided astronomers across the globe with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the universe at infrared wavelengths (2.5-240 μm).

218 citations

Journal ArticleDOI
TL;DR: To support a good interface between the FPA and downstream signal processing stage, both conventional and CMOS readout techniques are presented and discussed and future development directions including the smart focal plane concept are introduced.
Abstract: A discussion of CMOS readout technologies for infrared (IR) imaging systems is presented. First, the description of various types of IR detector materials and structures is given. The advances of detector fabrication technology and microelectronics process technology have led to the development of large format array of IR imaging detectors. For such large IR FPAs which is the critical component of the advanced infrared imaging system, general requirement and specifications are described. To support a good interface between the FPA and downstream signal processing stage, both conventional and CMOS readout techniques are presented and discussed. Finally, future development directions including the smart focal plane concept are also introduced.

201 citations

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