Analysis of startup, shutdown and middle sequences, Campaign 21c Abstract: As the IRS powered up for its final leg of Campaign 21, it came up in a strange state which led to highly unusual noise results for SL and elevated levels for the other three modules. After the startup anneal, though, all results were normal, and they remained so for the duration of the campaign. Except for the pre-anneal results in startup, SL and LL exceeded their noise limits only once, SH passed every time, and as usual, LH failed every time with SURN results between 18,7 and 21.0 DN. In the noise stability tests, LL varied at the 18-23% level, much like in Campaigns 19 and 20. It had settled somewhat in the first portion of this campaign. The photoresponse stability tests showed the following misbehaving pixels. In LL: (52,4) and (16,12). In LH: (84,114), (120,41), (67,66), (62,65). Analysts: Lei Hao & Greg Sloan Procedure version: 2.7 Campaign 21c, Startup, shutdown and middle anneal YEAR 2005 DOY 149 CE1 used for all data collection AORKEY = 15348992 for startup AORKEY = 13752576 for the first mid-campaign anneal sequence AORKEY = 13752832 for the second mid-campaign anneal sequence AORKEY = 13754112 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 8.8 117.2 8.5 15.0 0.0 12.2 SH 8.8 21.4 7.1 15.0 12.3 12.8 LL 14.5 23.6 12.2 15.0 11.7 12.9 LH 17.6 22.0 18.8 15.0 12.8 13.2 Unruly.pro results for the first middle (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 8.2 9.0 15.0 12.3 12.2 SH 8.8 6.8 7.0 15.0 12.8 12.7 LL 14.5 14.4 12.7 15.0 13.0 12.9 LH 17.6 19.7 19.0 15.0 13.3 13.3 Unruly.pro results for the second middle (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 8.3 8.7 15.0 12.3 12.3 SH 8.8 6.8 7.3 15.0 12.7 12.8 LL 14.5 13.9 12.8 15.0 13.1 13.0 LH 17.6 21.0 18.7 15.0 13.3 13.2 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 8.1 8.6 15.0 12.3 12.9 SH 8.8 6.7 7.0 15.0 12.8 12.8 LL 14.5 15.0 13.8 15.0 12.9 13.1 LH 17.6 19.9 19.8 15.0 13.3 13.4 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: The noise levels in the startup pre-anneal data are quite bizarre, probably because the IRS got caught in some transition state as we began the startup sequence. All modules showed high SURN results, and SL was off the charts in both SURN and SRSRN results. After the anneal, results had returned to normal, so there is no indication that the rest of Campaign 21 was affected. Otherwise, all SRSRN results were within limits. For SURN, SL exceeded its limit in 1 in 7 tests, SH passed all tests, LL failed once, and LH failed every time. The range of LH SURN results was 18.7-21.0 DN. Changes in read noise between anneals and from startup to shutdown (using the first mid-campaign seqeunce, which we have called IRS-002a): SUR data SRS data 002a-pre/ 003-pre/ 003-pre/ 002a-pre/ 003-pre/ 003-pre/ Module 001-post 002a-post 001-post 001-post 002a-post 001-post SL 0.97 0.90 0.95 1.00 1.01 1.01 SH 0.96 0.95 0.94 1.00 1.00 1.00 LL 1.18 1.18 1.23 1.01 1.00 1.00 LH 1.05 1.05 1.06 1.00 1.00 1.01 Comments: The SRSRN results remain stable within 1%. The SURN results were also stable, within 6%, except for LL, which ranged between 18 and 23% stability, exceeding the 20% yellow limit once. Photoresponse stability (using the middle middle IRS_002a): Module 002a-pre to 001-post 003-pre to 002a-post 003-pre to 001-post yellow red yellow red yellow red SL 40 0 12 0 12 0 SH 0 0 0 0 0 0 LL 3147 1 3679 2 3741 1 LH 8 3 6 2 8 1 Comments: The photoresponse results were very stable, with no latent images in the SL PU fields. As usual, the LL orders were clearly visible, and the LH orders were also visible, although they were weak. Pixels exceeding the red limit are: LL: (52,4) [3], (16,12) [1] LH: (84,114) [3], (120,41) [1], (67,66) [1], (62,65) [1]