Analysis of startup, shutdown and middle sequences, Campaign 18 Abstract: This campaign followed a solar flare event which occurred before the IRS powered on. The residual effects of this event are apparent in the noise results from the startup anneal sequence, but the following anneal sequences showed a return to normal behavior. All SRSRN results were within their limits, although the startup data were elevated slightly compared to the other anneal sequences. Ignoring the startup sequence, the SURN data were similar to previous campaigns, with SL exceeding its limit 5 of 8 times, LL exceeding its limit 2 of 8 times, and LH exceeding its limit every time. SH actually passed every test, including the startup sequence. The read noise stability tests reflect the initially poor results and the subsequent return to normal. The photoreponse stability tests showed no impact from the flare event, even in the initial data, and gave results much like previous campaigns. Analysts: Lei Hao & Greg Sloan Procedure version: 2.7 Campaign 18, Startup anneal YEAR 2005 DOY 035 CE1 used for all data collection AORKEY = 13149696 for startup AORKEY = 13148416 for the first mid-campaign anneal sequence AORKEY = 13148928 for the second mid-campaign anneal sequence AORKEY = 13149184 for the third mid-campaign anneal sequence AORKEY = 13149440 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 9.5 10.6 15.0 12.7 12.3 SH 8.8 6.7 7.5 15.0 12.8 13.0 LL 14.5 15.7 15.2 15.0 13.3 13.1 LH 17.6 22.5 20.2 15.0 13.7 13.6 Unruly.pro results for the first mid-campaign anneal (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 8.1 8.7 15.0 12.1 12.2 SH 8.8 7.0 6.9 15.0 12.8 12.7 LL 14.5 14.7 13.0 15.0 12.7 12.9 LH 17.6 19.3 19.2 15.0 13.2 13.2 Unruly.pro results for the second mid-campaign anneal (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 7.9 9.0 15.0 12.1 12.2 SH 8.8 6.9 7.0 15.0 12.9 12.7 LL 14.5 11.4 12.0 15.0 13.0 12.9 LH 17.6 18.0 18.3 15.0 13.2 13.3 Unruly.pro results for the third mid-campaign anneal (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 8.8 9.5 15.0 12.4 12.3 SH 8.8 7.2 7.1 15.0 12.8 12.9 LL 14.5 14.8 13.6 15.0 12.9 12.8 LH 17.6 19.8 18.8 15.0 13.2 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 9.1 8.9 15.0 12.4 12.3 SH 8.8 7.4 7.6 15.0 12.8 12.7 LL 14.5 12.0 12.9 15.0 13.0 13.1 LH 17.6 18.4 19.0 15.0 13.2 13.2 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: This is the first IRS campaign since the solar flare event in late January. In general, the noise data, started out poorly as the campaign began, but by the first mid-campaign anneal sequence had returned to behavior similar to previous campaigns. All SRSRN results are within limits, but many of the SURN results exceeded the limits. In the start-up sequence, only SH behaved well, while the other three modules failed both the pre- and post-anneal tests. In the remaining four anneal sequences, SL exceeded the 8.8 DN limit 5 out of 8 times, LL exceeded the 14.5 DN limit 2 out of 8 times, and LH exceeded its 17.6 DN limit in all cases. Comparison to previous campaigns: Comparing to the average SURN in all anneal sequences in Campaigns 15-17 to those in Campaign 18, excluding the start-up sequence, gives the following results: Average for Average for Module Camp. 15-17 Camp. 18 (start-up excluded) SL 8.8 +/- 0.6 8.8 +/- 0.5 SH 7.0 +/- 0.5 7.1 +/- 0.3 LL 12.6 +/- 0.9 13.1 +/- 1.3 LH 18.3 +/- 0.6 18.9 +/- 0.6 SL and SH have the same averages as before, while LL and LH are elevated slightly (0.5 and 0.6 DN respectively). It remains to be seen if the slight increase in LL and LH is an indication of permanent degradation of the detectors. Changes in read noise between anneals and from startup to shutdown: 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 1.02 0.86 0.98 1.01 1.00 SH 0.91 1.06 0.99 0.99 1.01 0.98 LL 0.75 1.00 0.79 0.99 1.01 0.99 LH 0.89 1.01 0.91 0.97 0.99 0.98 Comments: As usual, the SRSRN results are within 2% stability. The SL and LL results exceed the 20% yellow limit for SURN stability in comparisons involving the start-up sequence since the noise levels at start-up were elevated, but the comparison of the mid-campaign and shutdown data are quite stable. Photoresponse stability (using the middle middle IRS_002a): Module 002a pre to 001 post 003 pre to 002 post 003 pre to 001 post yellow red yellow red yellow red SL 0 0 0 0 0 0 SH 0 0 0 0 0 0 LL 8 5 1 0 6 4 LH 11 3 4 1 15 4 Comments: Both SL and SH behave well. The LL results are also good, except for one bright pixel in the 002a/001 comparison surrounded by a curcular region of faint pixels. The bright pixel is (56,97). The LH results are generally good, except for the usual small number of bad pixels. The LH orders are not visible. No effects of the solar flare event preceding this campaign are apparent in these tests. The pixels that over the red limit (10%) are: LL: (16,12) [2], (76,13) [1], (30,43) [2], (13,72) [2], (12,117) [1], (76,64) [1] LH: (67,66) [2], (15,74) [2], (84,114) [2], (70,48) [1], (120,41) [1]