Analysis of startup, shutdown and middle sequences, Campaign 26 Abstract: The noise and stability results for Campaign 26 are similar to Campaign 25, with LH well-behaved with its reduced bias voltage. LL may be worse behaved now and bears closer attention in future campaigns. The SUR read-noise limit for LH still needs to be adjusted downward. Analysts: Lei Hao & Greg Sloan Procedure version: 2.7 Campaign 26, Startup, shutdown and middle anneal YEAR 2005 DOY 317 CE1 used for all data collection AORKEY = 16284928 for startup AORKEY = 16333312 for the first mid-campaign anneal sequence AORKEY = 16333568 for the second mid-campaign anneal sequence AORKEY = 16284672 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 8.8 10.5 15.0 12.2 12.3 SH 8.8 7.2 7.5 15.0 12.7 12.9 LL 14.5 13.8 14.1 15.0 12.9 13.0 LH 17.6 12.4 11.9 15.0 12.9 12.9 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 7.7 8.5 15.0 12.2 12.2 SH 8.8 7.0 8.2 15.0 12.8 12.8 LL 14.5 14.8 13.2 15.0 13.1 13.0 LH 17.6 12.2 12.3 15.0 12.9 12.9 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 7.7 9.0 15.0 12.2 12.2 SH 8.8 6.9 6.9 15.0 12.8 12.8 LL 14.5 15.2 15.1 15.0 13.0 13.0 LH 17.6 11.9 11.2 15.0 12.9 12.7 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 8.0 9.2 15.0 12.2 12.4 SH 8.8 7.2 6.8 15.0 12.9 12.9 LL 14.5 15.2 13.7 15.0 13.0 13.1 LH 17.6 11.7 11.6 15.0 12.9 12.9 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 SRS results are all within limits. The SUR tests produce similar results to previous campaigns. SL exceeds the limit in 3 out of 8 cases, reaching noise levels as high as 10.5 DN. SH continues to behave well, with no cases outside the limit, and LH also behaves well with its new bias setting, with an average value of 11.9 DN compared to the official limit of 17.6 DN. LL is behaving more poorly than in previous campaigns, failing half the tests and reaching noise levels as high as 15.2 DN. Changes in read noise between anneals and from startup to shutdown (using the second mid-campaign seqeunce, IRS_002b): 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 0.74 0.95 0.77 0.99 1.00 0.99 SH 0.93 0.88 0.96 0.99 1.01 1.00 LL 1.05 1.15 1.08 1.01 1.00 1.01 LH 1.03 0.96 0.99 1.00 1.00 1.00 Comments: The SRS noise continues to be very stable, with no variations larger than 1%. The SUR noise is generally stable, except that SL showed variations of 26%, 5% and 23%; two of these three are beyond the yellow limit. The remaining SURN tests are within the yellow limit, with LH showing the least variation (less than 5%), SH staying with 12%, and LL within 15%. Photoresponse stability (using the second middle IRS_002b): Module 002a-pre to 001-post 003-pre to 002a-post 003-pre to 001-post yellow red yellow red yellow red SL 0 0 123 0 157 0 SH 15 0 0 0 0 0 LL 3336 6 3876 6 4922 7 LH 4 2 6 1 4 2 Comments: The SH comparison early in the campaign shows significant latent continuum and very bright emission lines. In LL, the orders are clearly visible and moderately bright, as usual. The LH orders are also somewhat visible in this campaign. In both comparisons involving shutdwon data, the PU fields in SL are quite bright. The red pixels are: (coordinates) [failures] LL: (52,4) [3], (76,13) [2], (76,64) [3], (53,86) [2], (87,99) [3], (47,105) [3], (4,108) [2], (118,73) [1] LH: (8,84) [3], (84,114) [2]