Electronic read noise

The cosmetics of the detector are excellent except for one quarter which is not functioning, probably due to a failed output amplifier. Otherwise, only part of one line in one quarter is dead, together with a few isolated pixels. The low pixel defect rate arises from the monolithic silicon construction of the device. The noise is dominated by shot noise arising firom emission by the output amplifiers. About 27,000 electrons are deposited per pixel in the least affected parts, rising to 4 times this in the worst. Thus the effective read noise is about 160 electrons. The electronic read noise per se is estimated to be about 30 electrons. Some progress is possible towards reducing the amplifier-induced noise, for example by deareasing the readout amplifiers ON time which is about 6 seconds at present. 

The combination of cooling and MPP can reduce the dark current to around 0.01-0.5 electrons/pixel/sec. At this level, the dark count for a 5-min exposure will be comparable to the read noise and not significantly affect the signal. 

For instance, to bring an n-type detector to the limit of Auger process suppression, electron concentration must be either equal to the product of nonequilibrium depletion factor and intrinsic concentration or lower than it (if the Shockley-Read noise component can be neglected). Thus, the product between the nonequilibrium depletion factor and intrinsic concentration represents the highest allowed level of doping of a given semiconductor for a given temperature. 

Abstract. We describe the development of a mid-in ared camera intended for use at the Palomai 5-m telescope and at the NASA Lifrared Telescope Facility. The camera is based on Rodrwell s HF-16 128x128 Si As BIB array. This array is unusual in that it has a well depth of approximately 30 million electrons tl will allow the use of traditional broadband astronomical filters (N and Q) while keeping a reasonable field-of-idew. Measured array performance indicates that it has a read noise of 1100 electrons and shows non-linearities of < 1% up to 65% of fall well. In this paper, we discuss the array and its operating characteristics and we give a brief overview of the camera design. 

An electronic noise component is also generated by the transfer of charges and by the preamplifier. For each readout process, one readout noise is generated. This readout noise is not very sensitive to temperature but increases with reading-out speed. Readout noise for a HCCD is about 10 electrons RMS or less. 

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