LORAL 2K

Bruce,

Mike Bessell asked me to send you the results of the tests on the 2k Loral CCDs. Below is a summary of the tests. So far, I have only spent time tuning 1 and 3 (RATING). 1 is now not usable because of the hot spot it developed and 3 is being used in dewar #15 on the imager. 5 has also been coatedand has been used on the 40" by Gary Da Costa and on the 16" by Sungeun Kim.It needs more time spent on it as the well depth is only 35000e. Judging by the results of tuning 1 and 3, I think I can probably get at leasttwo more useable CCDs and possibly as many as five, some with two amplifiers operational.

I won't be able to test any more CCDs until another dewar has been fitted out for these chips as dewar #15 will be used on the imager and I don't want to interfere with it any further and you will be using the other dewar on the 30". We at SSO are working on dewar #13 and it should be ready in about 3 weeks.

2k x 2k Loral CCDs: INITIAL TESTING RESULTS

CCD AMPLIFIER DATE RATING COMMENTS

12,0,0 upper 20-12-94 8 approx 6 bright columns (in dewar #4 8-June) also random bright spots

12,0,0 lower 21-12-94 6 columns, smeared last 200 columns. Some tuning tried. Noise less than 20e.
Both amplifiers will probably be useable with more tuning.

20,0,0 upper 21-12-94 9 many column faults and different response last 1024 rows

20,0,0 lower 21-12-94 none many column faults and different response on last 1024 rows May need a different setup for each half. No tuning or measurements attempted

14,1,0 upper 11-1-95 none doesn't see light

14,1,0 lower 11-1-95 6 column faults, noise 5adus gain ? No gain measurements done, but a gain of 2.5 to3 would be likely. About 12 column faults withone very bright one on the RHS.

4,0,0 upper 11-1-95 10 many column faults, some generating dark current

4,0,0 lower 11-1-95 none lower same as upper. Probably not useable

16,0,1 upper 13-1-95 4 4 4 bad columns, noise only 3adus

16,0,1 lower 13-1-95 none lower bright bars on LHS. No gain measurements done, but a gain of 2.5 to 3 would be likely. Both amplifiers look good enough to use.

9,0,0 upper 13-1-95 none bright columns, noise 6adus

9,0,0 lower 13-1-95 10 10 bright columns, dark current This was the first chip to be coated and has been used by Mike Bessell on the 16" and Gary Da Costa on the 40". Noise is 14e and it has about 10 column faults. The well depth is about 35,000e, but I am sure I can improve on that. This CCD is at MSO and will be put into a for the 30".

13,1,1 upper 18-1-95 13 no response to light, 18K bias, saturated?

13,1,1 lower 18-1-95 none won't balance, same as upper

1,0,0 upper 18-1-95 7 bright columns smeared hoizontally, noise 4adus

1,0,0 lower 18-1-95 none bias smeared, image ok. Both amplifiers will probably be OK with some tuning, although lower amp was much noisier

2,2,0 upper 24-1-95 12 won't tune saturated

2,2,0 lower 24-1-95 none won't tune saturated

15,0,0 upper 14-2-95 11 no response to light

15,0,0 lower 14-2-95 none no response to light

22,0,0 upper 15-2-95 2 no bad columns, noise 36e,10-16 mar tried tuning, not much improvement

22,0,0 lower 15-2-95 none no bad columns, noise 36e10-16 mar tried tuning I was able to get the noise from the lower ampdown to 12e with some tuning. I'll try this one next.

13,1,0 upper 21-2-95 1 bright columns, noise 13tried some tuning, noise 14e gain 2.8, need more time

13,1,0 lower 21-2-95 none 2 bright columns, noise 26. After tuning noise was 9e, dut developed a hot spot making it making it unusable.

21,1,1 upper 21-2-95 none 3 bright columns, one is 20 wide, noise 65e

21,1,1 lower 22-2-95 3 4 bright columns, noise 19e, gain 1.2 After tuning noise 11e, well depth 70,000e. A few bad bright on LHS, one column fault nearthe centre. Now in dewar #15 and used on the imager (using lower amp). The upper amplifier was almost as good, but I couldn't get the gain close to 1e/ADU without changing CCDI drastically.

CCD	AMPLIFIER	DATE	RATING	COMMENTS
12,0,0	upper	20-12-94	8	approx 6 bright columns (in dewar #4 8-June) also random bright spots
12,0,0	lower	21-12-94	6	columns, smeared last 200 columns. Some tuning tried. Noise less than 20e. Both amplifiers will probably be useable with more tuning.
20,0,0	upper	21-12-94	9	many column faults and different response last 1024 rows
20,0,0	lower	21-12-94	none	many column faults and different response on last 1024 rows May need a different setup for each half. No tuning or measurements attempted
14,1,0	upper	11-1-95	none	doesn't see light
14,1,0	lower	11-1-95	6	column faults, noise 5adus gain ? No gain measurements done, but a gain of 2.5 to3 would be likely. About 12 column faults withone very bright one on the RHS.
4,0,0	upper	11-1-95	10	many column faults, some generating dark current
4,0,0	lower	11-1-95	none	lower same as upper. Probably not useable
16,0,1	upper	13-1-95	4	4 4 bad columns, noise only 3adus
16,0,1	lower	13-1-95	none	lower bright bars on LHS. No gain measurements done, but a gain of 2.5 to 3 would be likely. Both amplifiers look good enough to use.
9,0,0	upper	13-1-95	none	bright columns, noise 6adus
9,0,0	lower	13-1-95	10	10 bright columns, dark current This was the first chip to be coated and has been used by Mike Bessell on the 16" and Gary Da Costa on the 40". Noise is 14e and it has about 10 column faults. The well depth is about 35,000e, but I am sure I can improve on that. This CCD is at MSO and will be put into a for the 30".
13,1,1	upper	18-1-95	13	no response to light, 18K bias, saturated?
13,1,1	lower	18-1-95	none	won't balance, same as upper
1,0,0	upper	18-1-95	7	bright columns smeared hoizontally, noise 4adus
1,0,0	lower	18-1-95	none	bias smeared, image ok. Both amplifiers will probably be OK with some tuning, although lower amp was much noisier
2,2,0	upper	24-1-95	12	won't tune saturated
2,2,0	lower	24-1-95	none	won't tune saturated
15,0,0	upper	14-2-95	11	no response to light
15,0,0	lower	14-2-95	none	no response to light
22,0,0	upper	15-2-95	2	no bad columns, noise 36e,10-16 mar tried tuning, not much improvement
22,0,0	lower	15-2-95	none	no bad columns, noise 36e10-16 mar tried tuning I was able to get the noise from the lower ampdown to 12e with some tuning. I'll try this one next.
13,1,0	upper	21-2-95	1	bright columns, noise 13tried some tuning, noise 14e gain 2.8, need more time
13,1,0	lower	21-2-95	none	2 bright columns, noise 26. After tuning noise was 9e, dut developed a hot spot making it making it unusable.
21,1,1	upper	21-2-95	none	3 bright columns, one is 20 wide, noise 65e
21,1,1	lower	22-2-95	3	4 bright columns, noise 19e, gain 1.2 After tuning noise 11e, well depth 70,000e. A few bad bright on LHS, one column fault nearthe centre. Now in dewar #15 and used on the imager (using lower amp). The upper amplifier was almost as good, but I couldn't get the gain close to 1e/ADU without changing CCDI drastically.

Note :

No tuning tried unless indicated.