To:sot_shift
from: Dan Schwartz
date: 10 Sep 99, 04:00pm EDT
Subject: SOT shift report, Shift L50
--------
See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or 
/proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Sep_10_1999_L50.txt.

Shift L50
	Start at 253:10:00  GMT
		 = 06:00am 10 Sep EDT
	End	   04:00pm 10 Sep
   
SOT Lead	DAS
Spac/Aspect	RAC
FOT/Sci liason	
HRC		
ACIS 		

(Times will be given in GMT on day 253. In general
times are rough, not precise.)

PLAN
Continue running load P12. HRC-I Cen A observations.
Diagnose ACIS energy resolution, run CAPs as appropriate.
Planned Comms   15:50 to 17:20
		22:00 to 00:00
	    254:07:35 to 08:55
EVENTS
at 253:10:00, out of comm. Running OBSID 463 on Cen A

Obtain additional comm time, spanning 18:45 to 00:00 GMT
	(2:45pm to 8pm EDT today).
15:50 AOS. Running OBSID 1253, observation of Cen A, with 
	5 stars and 3 fid lights.
	Comm is intermittent.
16:08  Start ACIS CAP 400 to raise FP to -90C 
	
16:15  Change OBSID to 62409, and change to format 2.
18:45  Start comm with Madrid
19:03  Terminate SSR playback:  too many errors.
19:07  stop science. CHange OBSID to 62408
19:27  Daily load is stopped.
19:47  Change OBSID to 62407


NOTES/ISSUES/PROBLEMS
We are thinking that we will move the SIM to position HRC at
the HRC-S focal position during the 15:50 to 17:20 comm.

Then we will power cycle ACIS and take event historgrams (and
faint mode event?) data during the extended comm, and return
the SIM to HRC-I aim position. We will allow the daily load
to continue uninterrupted, and we will NOT change any 
HRC instrument operations.

We've defined a new OBSID, 62409, for the switch to format
2 at 16:15 GMT, when we warm to -90deg to look for dark current.

At the 2pm meeting we defined the following approach:
	18:45 We will STOP the P12d load
	ACIS will finish dark current measurements at -90 deg C
	20:45 ACIS sets focal plane temp back to -100
	20:46 SIM move back to HRC-S
	21:45 take a baseline histogram and telemeter bias
	22:45 end baseline histogram
	22:46 Power cycle, load patches
	23:00 Take a comparison histogram
	23:50 Stop science run. 
	23:55 Start science run.
	23:56 OPTIONAL-To be decided- Lower focal plane temp?
  The early morning comm pass has been extended to be 07:35 
	to 11:25 (GMT). In this pass we plan to set the 
	Front Illuminated clock voltages to +/- 5v, just like
	the Back Illuminated chips. This requires some serious
	command loads to be built and verified in the next 12 hours.
   Also on the table under discussion is the possibility of lowering
	the temperature below -100 deg, in the -110 to -120 range,
	because lattice displacement effects would be expected to
	have a reduced effect on CTI at lower temperatures. However it
	is not clear we wish to do this because of the increased 
	possibility of condensation of contaminants at lower
	temperature.

The Cen A observation, 1253, was ended at 16:15 with a change to
format 2 and new OBSID 62409. OBSIDs 1173, 1174,1175,1176,1177,1178,
1179,1180, 464, and 1254 will therefore not be done in this load. They 
will need to be rescheduled in the future if still desired.
-------------------------------------------------------
Dan Schwartz,	MS #3
das@head-cfa.harvard.edu  
phone: (617)495-7232    FAX:   (617)495-7356
cell phone: (617)512-5627   
pager: 800-759-8352 PIN 1636502
       or e-mail 1636502@skytel.com 
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