FLAMINGOS --- Detector Information


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Rockwell PACE-1 HAWAII-2 Arrays Used by FLAMINGOS
Device
Engineering Array
Science Grade Array
Bare Mux
Date Installed
Fall 2000 through September 2002
September 2002 to present
Fall 2000
Serial Number
  • 10
  • 43
  • M8
Det Layer ID

  • 9-321L
n.a.
Mux ID

  • L3W1D3
n.a.
J-band QE
  • Mean QE = 0.318
  • Std Dev of QE = 0.164
  • Stddev / Mean = 0.515
  • Yield (number of pixels out of 2048x2048 pixels) = 0.9999
  • Max QE = 1.000
  • Min QE = 0.000
  • Still locating data sheets.
  • If it is similar to the FLAMINGOS-2 science array, then the J-band QE is probably about 0.7, with a standard deviation that is a littler tighter (about 0.13).

H-band QE
  • Mean QE = 0.592
  • Std Dev of QE = 0.067
  • Stddev / Mean = 0.113
  • Yield (number of pixels out of 2048x2048 pixels) = 0.9999
  • Max QE = 1.000
  • Min QE = 0.000
  • Still locating data sheets.
  • If it is similar to the FLAMINGOS-2 science array, then the H-band QE is probably about 0.7, with a standard deviation that is a littler tighter (about 0.13).

K-band QE
  • Mean QE = 0.590
  • Std Dev of QE = 0.065
  • Stddev / Mean = 0.111
  • Yield (number of pixels out of 2048x2048 pixels) = 0.9998
  • Max QE = 1.000
  • Min QE = 0.000
  • Still locating data sheets.
  • If it is similar to the FLAMINGOS-2 science array, then the K-band QE is probably about 0.7, with a standard deviation that is a littler tighter (about 0.13).


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Crosstalk on the Science Grade Array
  • Our science grade array exhibits crosstalk between amplifiers.  I don't remember seeing it on the engineering grade array, but that's not to say it wasn't there at a lower level.
  • We read out all 32 amplifiers of the array; each quadrant is read into one A/D caard containing 4 A/D inputs; the 8 amplifiers are muxed in pairs to one of the 4 A/D inputs on the card.
  • During July/August 2003 we did a little investigation on the nature of the crosstalk.  Four images (raw CDS frames) are presented here; click on the images for a larger view; gzipped fits files are linked below.
  • No, we don't have any suggestions on how to deal with it in your data.  I think our two survey teams have found ways to reject them when identifying sources, but you'd have to talk to one of the PIs.
  • A pinhole source was directed at amplifier #2, within quadrant #1.
  • The source signal peaked at about 21,000 ADU, the bias level is about 350 ADU.
  • Approximately +/-128 pixels (the width of one amplifier) away lie the crosstalk signals, in amps 1 and 3.
  • The crosstalk signals look like little positive and negative half-sources (~+/-150 ADU about bias level).
  • Some of the experiments showed that cross talk occurs when the bright source lands on an even-numbered amplifer, but not when it landed on an odd-numbered amplifier.
  • q1.amp2.preamp.30sec.0001.fits.gz (4.8 MB)
Labeled view thumbnail
  • A zoom in on the previous image.
zoom of cross talk on quad 1
  • Same setup as in previous image, except that we disabled the opamp for channel 2 in the preamp.
  • The crosstalk signals are still present (at center of black circles), thus the cross talk is not a function of our preamp.
  • This implies to us that the cross talk occurs within the detector itself.
  • q1.amp2.preamp2.30sec.0005.fits.gz (4.8 MB)
xtalk amp 2 off
cross talk in quad 4
  • A bright slit was directed at several amps in quadrant 4.  Cross talk bands appear in all other quadrants.  We have seen this on the telescope with very bright sources and long-slit spectroscopy.
  • xtalk.5.0001.fits.gz (5.1 MB)
Bright slit xtalk


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Last updated 2004 August 18, Wednesday
S. Nicholas Raines