Analysis of startup, shutdown and middle sequences, Campaign 12 Abstract: All SRSRN results are within limits. As in previous campaigns, SH and LL are within the SURN limits, but SL and LH are more problematic. SL fails in two cases and LH fails slightly in three. LH may be improving slightly. The SRSRN results remain very stable, as in previous campaigns, and the SURN results are more stable than in past campaigns, with three modules well within the 20% yellow limit and SL just reaching it. The photoresponse stability produces some unusual results. The same three pixels which fail in LL in previous campaigns continue to fail (16,12, 64,27, and 76,64), and SH shows very good behavior, but LH and SL are both affected by latent images. In LH, the latency is not strong, but it is enough to illuminate the orders. LH pixel 15,74 continues to fail. The SL array shows strong latent images in the mid-campaign data (a single spectrum in both apertures with a bright blob in the red PU array) and in the shutdown data (apparent double star in the the red PU array). Analysts: Lei Hao & Greg Sloan Procedure version: 2.7 Campaign 12, Startup, Shutdown and Mid-campaign anneal YEAR 2004 DOY 240 CE1 used for all data collection AORKEY = 11913472 for startup AORKEY = 11912960 for the mid-campaign anneal sequence AORKEY = 11913216 for shutdown Number of files = 64 for each 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 8.2 9.4 15.0 12.1 12.2 SH 8.8 7.3 7.1 15.0 12.8 12.9 LL 14.5 12.3 12.7 15.0 12.7 13.1 LH 17.6 17.1 17.7 15.0 13.1 13.3 Unruly.pro results for middle (IRS-002): 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 8.9 15.0 12.3 12.3 SH 8.8 6.4 7.1 15.0 12.7 12.7 LL 14.5 11.8 13.2 15.0 13.1 12.8 LH 17.6 17.8 17.9 15.0 13.2 13.1 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 7.5 8.6 15.0 12.3 12.2 SH 8.8 6.7 7.3 15.0 12.8 12.7 LL 14.5 12.8 11.9 15.0 12.9 12.9 LH 17.6 17.6 16.9 15.0 13.3 13.0 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 SRSRN data are within limits. Both SH and LL SURN are within limits, as in the previous campaigns. SL SUR again has two counts of over the limit: after the anneal at startup (9.4DN) and in the middle of the campaign (8.9 DN). The LH SURN continues to behave as in Campaign 11, with three measurements slightly over the limit (maximum 17.9 DN, which is a 2% discrepancy) and one measurement right at the limit. The counts under the limit are more under the limit than in Campaign 11. While LH is still over the 17.6 DN limit consistently, as it has been since the middle of Campaign 7, it may be improving slightly. Changes in read noise between anneals and from startup to shutdown: SUR data SRS data 002pre/ 003pre/ 003pre/ 002pre/ 003pre/ 003pre/ Module 001post 002post 001post 001post 002post 001post SL 0.87 0.85 0.80 1.01 1.00 1.01 SH 0.91 0.95 0.95 0.99 1.00 0.99 LL 0.93 0.97 1.01 1.00 1.01 0.99 LH 1.01 0.98 1.00 0.99 1.02 1.00 Comments: The SRSRN results remain very stable, with only LH varying at a 2% level. The SURN results are more stable than they have been in recent campaigns; only SL reaches the yellow limit, with a 20% variation from the beginning to the end of the campaign. LH continues to be the most stable, with only 2% variations. Photoresponse stability: Module 002 pre to 001 post 003 pre to 002 post 003 pre to 001 post yellow red yellow red yellow red SL 162 14 359 53 370 50 SH 0 0 0 0 0 0 LL 81 1 2146 3 4129 3 LH 1 0 3 1 5 1 SH shows no pixels exceeding either the yellow or red limit. LH shows behavior similar to Campaign 11, with several pixels exceeding the yellow or red limits. The only LH pixel exceeding the red limit is 15,74, which has failed repeatedly in the past. The orders are clearly visible in LH, which is a cause for concern. LL continues to exhibit poor stability, with the orders clearly visible. Three pixels exceed the red limit, and all three also failed in Campaign 11: 16,12, 64,27, and 76,64. SL shows very strong latent images in all comparisons (see the postscript files saved in the IRS_002 and IRS_003 directories). These latencies all but invalidate any efforts to look for changes in the detector properties. They show up as a single latent mapping spectrum in SL1 and SL2 accompanied by a blob in the red PU array in the mid-campaign data and as an apparent double star in the the red PU array in the shutdown data.