In each of these curves 3s separates one data point from the next. Flux here is broadband, with no intervening optical elements between the blackbody aperture and the array. Haven't done a flux calculation yest, but we could do a QE estimate from this data as well.
Up to about 30K there isn't much coming off the blackbody above whatever the background light leak in the dewar is (~80e/s). Signal is pretty linear for the 35K curve, and we appear to be clipping at the source-follower for the 40K and 45K curves. We'd need to drop the detector bias below 2V if we wanted to get a smooth debias fit to the data.
The right-hand axis is scaled to give an idea of equivalent electrons, and the swing appears to be about 300k electrons. Since it will cost us some responsivity to deepen the well further, we should consider how big a background we want to consider handling. If we ran at -2V (or even -3V), we could conceivably stay reasonably linear up to 300k electrons, which at a 2Hz scan rate and 50% quantum efficiency would work out to something like 1.2M ph/pix-s. Is that enough?
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As we talked about yesterday, the largest flux will come from the blackbody when we are in flight. Since our blackbody can be cooled, it won't be quite as bright as what is expected just looking in the lab. A 273 K blackbody has about <85% of the photons at all wavelengths compared to a 295 K blackbody. The peak flux at low resolution with typical choices for slit width and grating angle is <4e6 electrons per second per pixel. That says we may need to read out only 256 pixels at those settings.
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