HET End-Trimester Report
Second Period of 2002
April 1 - July 31

In this section we will discuss the status of each instrument and any limitation to configurations that occurred during the period.

• LRS: The LRS guide camera has been the main limitation to science with the LRS during this period. The LRS was without a guide camera for 16 nights. On 2 other science nights the G2 grating was not available. On June 12 the HgCdZn lamp died and was replaced by the spare Cd lamp from the 107". No new HgCdZn lamps have been found to be purchased.

• SAMS: Near the end of the period SAMS suffered from a number of failures and was offline for 7 nights. Although this does not stop us from doing science it does require that more time is spent stacking.

• HRS: The guide camera for the HRS has been the main limitation to science with the HRS during this period. The HRS was without a guide camera for 13 nights. On 2 other science nights the Iodine Gas Cell was not available.

• Instrument Commissioning: During this period there were 10 nights of LRS IC.

• Engineering: During this period there were 10 nights of engineering: 6 nights of MARS engineering and 4 nights of Hartmann engineering. A significant overhead for each night is the 2 stacks that we conduct during the night regardless of the stack condition for SAMS testing. This adds about 30 minutes per stack (although sometimes the stack is required because of SAMS failure to compensate for temperature changes). On a number of nights during this period small engineering tests were conducted along side science observations or during cloudy weather.

The image quality of the HET has improved a bit over last year.

For comparison here is the image quality for the same period of 2001

Month by Month Summary

Month	A:Fraction of the Time that was Possible Science	B:Average Night Length	C:Fraction of Time Lost due to Weather	D:Fraction of Science Time Lost due to Alignment	E:Fraction of Science Time Lost due to Calibrations	F:Fraction of Science Time Lost due to Problems
April	0.775	8:16	0.52	0.29	0.03	0.11
May	0.777	7:14	0.32	0.22	0.02	0.14
June	0.952	6:39	0.36	0.21	0.03	0.02
July	0.83	6:56	0.49	0.11	0.02	0.06

July numbers for the above table not available at time of report.

The total number of acceptable shutter open hours during this period is 140 hours. This number is based upon our queue data base. There were a number of rejected spectra obtained during this period as well the following table give the total number of rejected spectra and the category that each falls into.

Number of Times	Time Lost (Hours)	Type
5	3.7	E - Rejected by RA for Equipment Failure
4	0.9	H - Rejected by RA for Human failure
17	6.4	W - Rejected by RA for Weather
1	0.3	P - Rejected by PI and confirmed by RA
0	0.0	C - Acceptable by RA but PI rejects
2	0.3	N - Acceptable but NOT charged due to weather or hole in queue
16	5.4	B - Acceptable but Border line conditions

So this is a total of 11.6 hours of rejected spectra with an additional possible 5.4 hours of spectra that may be rejected.

The following is a summary of the Acceptable CCD shutter time for each institution based on our htopx data base. It does not include any overhead.

Time Usage by Institution (hours)
-TOTAL-	Used	% of All
PSU	39.351	29.4
UT	75.429	56.3
Stanford	10.375	7.7
Munich	3.757	2.8
Goetting	5.000	3.7
NOAO	6.583	--
SALT	0.000	--
DDT	0.000	--

This is how each institution has allocated its time by priority.

Time Allocation by Institution (hours)
Institution	Priority 0	Priority 1	Priority 2	Priority 3	Priority 4
PSU	1.670 (1%)	42.930 (26%)	42.000 (25%)	30.600 (18%)	49.000 (29%)
UT	24.000 (9%)	103.400 (41%)	70.800 (28%)	54.500 (22%)	0.000
Stanford	0.000	21.750 (100%)	0.000	0.000	0.000
Munich	0.000	0.000	0.000	0.000	0.000
Goetting	0.000	0.000	0.000	0.000	0.000
NOAO	0.000	53.700 (73%)	20.000 (27%)	0.000	0.000
SALT	0.000	0.000	0.000	0.000	0.000
DDT	0.000	0.000	0.000	0.000	0.000