Oct_29_1999 Shift M98 Start at 1999:302:16:00:00 GMT End 302:21:00:00 GMT See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or /proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Oct_29_1999_M98.txt. SOT Lead Ed Kellogg SOT FP FOT-SI HRC-SI ACIS-SI OTHER Plan: - Running P23 load. EVENTS DONE OBSID -------------- ---- ----- Perigee 1247 Proton2 rad exit 1354 Start Shift, LOS 1600 NOTES/ISSUES/PROBLEMS --------------------- We are supposed to be running 62331, ACIS CTI, but have no TLM data to confirm that. The last reading(see snapshot below) was 62333, as shown in the DOT. ACIS telecon ------------- Mark Bautz: has not heard of any CTI change. Lab work at GSFC finds a way to improve CTI in a chip damaged by protons from 3e-4 to 5e-5 by lengthening the transfer time from the image area to the frame store. Damage was induced over a small fraction of the chip, so the implications for a full readout are not fully known. Squeegee mode tests were not possible at GSFC with the chip used, but it will be pursued. Damage from 390 keV protons is the same as from those at 40 MeV. At 157 keV it's up another factor of two, and at 100 keV, up another factor of 1.5. Energy of protons determines ratio of damage to buried channel to that in depleted region, => ratio of increase in dark current to that in CTI. Steve O'Dell: thinks we want to change the rad belt model to MSM, but not just yet. Might want get the model improved to describe higher energies. Gordon Garmire: Dave: runs at GSFC 200,100 keV, irradiated CCD cold in camera. Results are confusing. Perhaps beam is wandering on the chip. Very little increase in dark current, Harder to tell what's happening to CTI. Plan to go again with MIT in several weeks. Will look at effect of warming up after proton exposure. At 200 keV, get ~10% total reflection of protons. Rob: safing - building SCS for autosafing - TRW has it built, walkthru next week, review late next week. The FOT is providing realtime safing capability; Bruce has script, rev 1.6, in signoff. The OC's are briefed on running it, and they're looking for an opportunity to try it before a rad entry. RADMON thresholds: define levels for EPHIN triggers, use data from ACE spacecraft, got a system, are defining fluence & flux thresholds. Peter Ford: FEP0 anomaly - success in lab. Dorothy Gordon finds mechanism can be capacitive coupling on two leads on an IC. Don't see any QC or design flaws in the board. Not clear yet whether it's getting worse or not. Are developing & testing a patch. It will extract diagnostic info on errors, and return FEP0 to useful activity. It is now in final test in eng'ng unit. After ten bias parity errors per frame, patch restricts processing to lower 512 rows, closest to output node and stores info. In cont. clock mode, inhibits all bias parity error reporting. Recommend to uplink the patch as soon as ready and permitted. It will then be necessary to tell users that one CCD may well be cut in half. From the chandra snapshot ------------------------- UTC 1999:302:20:08:00 (Fri Oct 29) OBT 1999:302:15:59:57 CTUVCDU 10914815 FMT2_NORM OBC s/w NRML OBC Errs 0 OBT 57599997.82 ONLVCDU 10914808 OBSID 62333 EPState SUN SIM TTpos -99616 HETG Angle 81.0 PCADMODE NPNT RA 101.307 Bus V 30.71 SIM FApos -1047 LETG Angle 82.1 PCONTROL NPNT Dec -16.720 Bus I 25.45 AOFSTAR GUID Roll 70.518 ACA Object SSSSSSSS Dither ENAB HRC-I HV OFF ACA ImFunc TTTTTNNN Dith Yang 8.25 Yaw Rate -0.20 HRC-S HV ON ACA CCD Temp -10.4 Dith Zang -5.51 Pitch Rate 0.10 OBSMode NEXT ACA Int Time 1.698 Roll Rate 0.02 Door OP UNAC AOACSTAT OK FSS SunAlfa SUN Door CL UNAC FSS Alfa -0.89 Batt 1 SOC 100.00% Avg HRMA Temp 70.61 FSS Beta -16.82 Batt 2 SOC 100.00% Avg OBA Temp 50.66 SA Resolv 106.38 Batt 3 SOC 100.00% ACIS Stat7-0 66 OBA Tavg Fault NFLT SA Sun Pres ILLM Cold Rad -115.9 OBA Trng Fault NFLT Warm Rad -79.6 HRMA power 31.50 OBA power 133.70 EPHIN Geom LARG INT cnt 31 Roll Mom. 3.408 P41GM cnt 2 Pitch Mom. -4.459 A-Leak 0.2920 Yaw Mom. -4.029 B-Leak 0.0400