Analysis of startup, shutdown and middle sequences, Campaign 25 Abstract: Campaign was the first campaign with LH set at its new lower bias voltage, and the module is much better behaved as a consequence. We need to adjust the SUR read-noise limit downward for future campaigns to account for this improvement. The other modules behaved much as they have in the past, with SL exceeding its SURN limit about half the time and the responsivity images showing residuals in SL, LL, and occasionally, LH as well. Analysts: Lei Hao & Greg Sloan Procedure version: 2.7 Campaign 25, Startup, shutdown and middle anneal YEAR 2005 DOY 282 CE1 used for all data collection AORKEY = 16069888 for startup AORKEY = 16068864 for the first mid-campaign anneal sequence AORKEY = 16069120 for the second mid-campaign anneal sequence AORKEY = 16069376 for the third mid-campaign anneal sequence AORKEY = 16069632 for shutdown Number of files = 64 for each except for the second mid-campaign, which has 65 files. There are two copies of EXPID 0024, DCE 0001: IRSX.2.0016069120.0024.0001.01.mipl.fits IRSX.2.0016069120.0024.0001.02.mipl.fits We used the second one. No known errors. Steps 2 through 5 run OK. Unruly.pro results for startup (IRS-001): Noise characteristics of the modules (in DN) SUR data SRS data noise pre post noise pre post Module limit anneal anneal limit anneal anneal SL 8.8 8.4 9.1 15.0 12.2 12.3 SH 8.8 7.5 7.5 15.0 12.8 12.8 LL 14.5 13.8 12.2 15.0 13.0 12.9 LH 17.6 11.3 12.0 15.0 12.8 12.7 Unruly.pro results for the first middle sequence (IRS-002a): Noise characteristics of the modules (in DN) SUR data SRS data noise pre post noise pre post Module limit anneal anneal limit anneal anneal SL 8.8 8.6 8.8 15.0 12.2 12.3 SH 8.8 7.0 7.7 15.0 12.8 12.8 LL 14.5 14.2 15.0 15.0 13.2 13.0 LH 17.6 11.7 11.6 15.0 12.9 12.7 Unruly.pro results for the second middle sequence (IRS-002b): Noise characteristics of the modules (in DN) SUR data SRS data noise pre post noise pre post Module limit anneal anneal limit anneal anneal SL 8.8 7.9 9.3 15.0 12.1 12.1 SH 8.8 6.9 7.8 15.0 12.9 13.2 LL 14.5 13.5 12.0 15.0 13.1 13.0 LH 17.6 12.0 12.4 15.0 12.8 12.8 Unruly.pro results for the third middle sequence (IRS-002c): Noise characteristics of the modules (in DN) SUR data SRS data noise pre post noise pre post Module limit anneal anneal limit anneal anneal SL 8.8 8.2 9.0 15.0 12.3 12.3 SH 8.8 6.7 7.2 15.0 12.9 12.8 LL 14.5 13.1 13.2 15.0 13.1 13.0 LH 17.6 12.2 11.3 15.0 12.8 12.9 Unruly.pro results for shutdown (IRS-003): Noise characteristics of the modules (in DN) SUR data SRS data noise pre post noise pre post Module limit anneal anneal limit anneal anneal SL 8.8 8.6 9.6 15.0 12.2 12.4 SH 8.8 6.7 7.7 15.0 12.8 12.8 LL 14.5 13.1 14.1 15.0 13.1 13.0 LH 17.6 11.9 11.4 15.0 12.9 12.7 The analysis applied the PIRAT procedure unruly.pro to FITS files generated by MIPL. For SUR data, the quoted values are the standard deviation of the read noise map. For SRS data, these are the median of the standard deviation map. Comments: All SRS resutls are within the limit, as usual. The SL SURN tests stayed within the limit for all pre-anneal sequences but were at or beyond the limit in all post-anneal tests, with values from 8.8 to 9.6 DN. The SH SURN results are within limits, as with previous campaigns. The LL SURN results exceeded the limit in only one of ten tests: 15.0 DN in the first of the mid-campaign sequences (post-anneal). The LH SURN results are very well behaved after lowering the bias voltage, with the highest result at 12.4 DN, compred to the previousl limit of 17.6 DN. The limit needs to be adjusted downward. Changes in read noise between anneals and from startup to shutdown (using the second mid-campaign seqeunce, IRS_002b): SUR data SRS data 002b-pre/ 003-pre/ 003-pre/ 002b-pre/ 003-pre/ 003-pre/ Module 001-post 002b-post 001-post 001-post 002b-post 001-post SL 0.86 0.92 0.94 0.99 1.01 0.99 SH 0.91 0.85 0.88 1.01 0.97 1.00 LL 1.11 1.09 1.07 1.01 1.01 1.01 LH 1.00 0.96 0.99 1.01 1.01 1.01 Comments: The noise stability is good, with very stable SRS results, with all but one comparison at 1% or better. The exception was the SH comparison of the final pre-anneal sequence with the mid-campaign post-anneal sequence, which showed a 3% variation, the highest we have seen. All comparisons of SURN results were within the yellow limit. LH was particularly stable, with the worst case being a 4% variation. The other modules varied by about 10% on average, with the worst case being SH in the same test that was a problem for the SRS data. Photoresponse stability (using the second middle IRS_002b): Module 002b-pre to 001-post 003-pre to 002b-post 003-pre to 001-post yellow red yellow red yellow red SL 14 0 2024 128 2210 237 SH 0 0 0 0 0 0 LL 3344 7 3276 3 4607 5 LH 3 2 4 1 5 1 Comments: The SH remains good. The SL comparison images show bright sources in the PU fields. Both PU subarrays are clearly visible in the comparison between 003-pre-anneal and 002b-post-anneal data, with a latent image in the bottom right corner of the Blue field that also shows up in the other comparison using the shutdown image. In the 003-002b and 003-001 comparisons, the Red field is significant brighter than than the Blue field, and a latency resembling a double star is apparent in the blue field. The LL slits is clearly visible, as usual, in all comparisons. Emission lines are also apparent in both orders. The LH orders are visible in the comparisons involving the shut-down images, and an emission line is present as well. The comparison between start-up and the mid-campaign sequence is fine. The pixels exceeding red limit are: (coordinates)[times] LL: (52,4) [3], (76,13) [2], (64,27) [1], (76,64) [2], (83,77) [1], (87,99)[1], (47,105) [3], (118,73) [2] LH: (8,84) [3], (84,114) [1]