DEIMOS
Lots 9 and 10 CCD Test Results (epi CCDs)
June 21, 1999:
I. DEIMOS minimal specifications for Grade A epi CCDs:
* CTE no worse than 0.99990 (means 10% of electrons in trailing pixel with two
amplifiers).
* Dark current less than 20 e-/hr/px (red sky count between the OH at highest
dispersion)
* Goal: 60 sec readout (1-4us clock overlaps with two amplifiers)
* No major glowing hot spots during 1000 sec dark.
II. Expected numbers of good CCDs from Lots 9 and 10
Lot 9: 12 tested, 9 Grade A or A-. % good = 75%
Lot 10: 14 tested, 4 Grade A or A-. % good = 29%
Lot 9 is better than Lot 10.
We own 25% of both lots; each lot produces 72 CCDs.
Expected from Lot 9: 72 x 0.75 x .25 = 13 CCDs
Expected from Lot 10: 72 x 0.29 x .25 = 5 CCDs
Total = 18 CCDs
Needed epi's for DEIMOS:
8 CCDs + 2 spares if whole detector is epi
4 CCDs + 1 spare if detector is half epi and half high-rho (the high-rho
run is just starting)
Conclusion 1: It is likely that we will get at least a minimal complement of
DEIMOS CCDs from Lots 9 and 10
Conclusion 2: Roughly 144 CCDs will need to be tested. Each CCD takes one
day. If Mingshi does nothing else but test CCDs it will take 25 weeks.
We need a more efficient testing program.
III. Acknowledgements
DEIMOS would like to thank Richard Stover and particularly Mingshi Wei for
the tremendous effort they have made on this program and for the huge amount of
work left to do!
IV. Raw data
Clock overlaps correspond to the following total RO times with 2 amplifiers:
1-1us: min. read out time: 7us/px 28 sec
1-2us: min. read out time: 10us/px 40 sec
1-4us: min. read out time: 16us/px 64 sec
1-8us: min. read out time: 28us/px 128 sec
Table 1
Summary of Serial CTEs at -90c
CCD dark Grade 1-1us 1-2us 1-4us 1-8us
(e-/h/p)
10-2-3 5.7 A 0.99995068 0.99996529 0.99998095 0.99999228 higher Vv fixes it
9-3-6 5.6 A 0.99994661 0.99996796 0.99997679 0.9999912
9-4-6 5.0 A- 0.99994074 0.99995800 0.99997348 0.9999957 hot column and dark glow
10-3-5 3.9 A 0.99993587 0.99994542 0.99996698 0.99998085 one dark column
9-1-3 6.7 A 0.99992941 0.99994542 0.99996698 0.99998139
9-2-6 3.4 A 0.99993275 0.99995292 0.99996604 0.99998660
9-6-2 5.2 A 0.99991962 0.99993945 0.99996569 0.99998086
9-2-3 6.4 A 0.99989522 0.99991867 0.99995952 0.99997001
9-2-4 6.2 A 0.9998835 0.99990581 0.99994856 0.99997752
9-4-1 6.1 B+/A- 0.99972373 0.99979501 0.99988667 0.99996086 need higher Vv; probably
fixable; 2 hot cols, poor
CTE
9-6-4 7.8 B 0.99962793 0.99976251 0.99985833 0.99994249 1/2 of CCD has v. bad CTE
CCDs tested once but not retested -- some performances are extrapolated:
9-3-1 A- loaned to Stubbs; higher Vv should fix; CTE looks standard
9-3-4 A loaned to Stubbs
9-1-6 B super hot column
10-1-1 B glowing spots
10-1-2 B glowing spots and hot belt
10-2-5 B glowing spots, need higher Vv , very bad serial CTE on 1/2 CCD
10-2-6 B glowing spots, need higher Vv
10-3-2 B very bad serial CTE
Results on 7 extra Lot 10 CCDs: 7 tested, 2 Grade A. The rest mostly Grade B.
Table 2
Serial CTE vs. temperature and clock times
10-2-3
dark(e-/h/p) 1-1us 1-2us 1-4us 1-8us
-80c N/A 0.99997947 0.99998542 0.99999422 0.99999569
-85c N/A 0.99996856 0.99997445 0.99998641 0.99999233
-90c 5.7 0.99995068 0.99996529 0.99998095 0.99999228
9-3-6
-80c 49.3 0.99996942 0.99998176 0.99999620 0.999999
-85c 12.9 0.99996475 0.99997679 0.99998853 0.99999511
-90c 5.6 0.99994661 0.99996796 0.99997679 0.9999912
9-4-6
-80c 74.8 0.99997495 0.9999879 0.999999 0.999999
-85c 29.2 0.9999510 0.99996382 0.999986 0.9999977
-90c 5.0 0.99994074 0.99995800 0.99997348 0.9999957
10-3-5
-80c 30.0 0.99997745 0.99998167 0.99998691 0.999999
-85c 17.0 0.99995550 0.99996497 0.99998486 0.999999
-90c 3.9 0.99993587 0.99994542 0.99996698 0.99998085
9-1-3
-80c 106.7 0.99997198 0.99999042 0.99999623 0.999999
-85c 21.1 0.99994828 0.99996901 0.99998771 0.99999528
-90c 6.7 0.99992941 0.99994542 0.99996698 0.99998139
9-2-6
-80c 21.0 0.9999667 0.99998167 0.99998906 0.999999
-85c 13.0 0.9999549 0.9999723 0.99998741 0.99999464
-90c 3.4 0.99993275 0.99995292 0.99996604 0.99998660
9-6-2
-80c 52.2 0.99995625 0.99998055 0.99998585 0.99999474
-85c 30.9 0.9999308 0.99995924 0.9999777 0.99999075
-90c 5.2 0.99991962 0.99993945 0.99996569 0.99998086
9-2-3
-80c 69.2 0.99994992 0.99996625 0.9999875 0.99999780
-85c 15.7 0.99994006 0.99996534 0.99997761 0.99999760
-90c 6.4 0.99989522 0.99991867 0.99995952 0.99997001
9-2-4
-80c 47.6 0.99992345 0.9999736 0.99999109 0.999999
-85c 12.7 0.99994473 0.99993112 0.99996447 0.99999136
-90c 6.2 0.9998835 0.99990581 0.99994856 0.99997752
9-4-1
-80c 56.8 0.99986647 0.99993475 0.99997127 0.99999352
-85c 15.9 0.99978699 0.99985015 0.99994074 0.99998116
-90c 6.1 0.99972373 0.99979501 0.99988667 0.99996086
9-6-4
-80c 76.5 0.99989555 0.99994249 0.99998531 0.999999
-85c 15.6 0.99975956 0.9998386 0.9999217 0.99997591
-90c 7.8 0.99962793 0.99976251 0.99985833 0.99994249