Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/smov/SMOV4%20WEB%20PAGE%20OCT2007/smov4notes/ACSScienceSMOVUpdateMay31.pdf Дата изменения: Wed Jun 3 19:41:53 2009 Дата индексирования: Sat Mar 1 23:54:07 2014 Кодировка: Поисковые слова: tail

ACS Science SMOV Update - 1
David Golimowski (31 May 2009) SBC UV Contamination Check (Prop 11372) · · Visit 1 completed (observations of NFC 6681 through 5 standard filters and PR110L0) Analysis of data underway at STScI. See separate report.

ACS-R Optimization Campaign (STScI analysis) · Internal CTE analysis indicates: (1) CTE tails from hot pixels and cosmic rays indicates that CTE has degraded that is consistent with or slightly better than pre-Jan 2007 extrapolations. (2) EPER tests, however, indicate that measured CTE (0.99989 at 1620 e-) is lower than expected from pre-failure extrapolation (0.99992), and lies just below the "problematic" threshold (0.9999) for science. Changes to parallel and serial clock rails have no impact on the measured CTE, indicating that effects of radiation damage dominate clocking patterns.


ACS Science SMOV Update - 1
David Golimowski (31 May 2009)

ACS-R Optimization Campaign (GSFC/Teledyne) · Analysis of O-mode data indicates that: (1) Timing of all clocks are nominal, notwithstanding the minor drift of the ASIC ADC clock noted (and resolved) yesterday. (2) Variations of high-rail of Reset Gate yield no perceptible changes in O-mode traces other than sampling noise. Conclude that changes in RG rails (i.e., changes in preamp settling) do not affect analog video signal. Default RG rails are fine. (3) Variations of serial-clock rails yield no perceptible changes in Omode traces other than sampling noise. No observable impact on analog video feedthrough due to changing serial clock rails and amplitudes. Changes to these rails suggested from other tests will not negatively affect noise in video signal.


ACS-R Performance Summary
Metric Read noise (e-; gain = 2) Dark current (e-/pix/hr) Hot pixels (%) Full well depth (e-) Non-linearity (%) CTE (1620 e-) Cross-talk Jan 2007 (actual) C&S: 5.5 10.7 0.68 84,000 < 0.1 0.999949 4x10
-5

May 2009 Problematic (predicted) DSI: 4.0 15 1.1 84,000 < 0.1 0.999921 4x10
-5

May 2009 (OC Iter 1) DSI: 4.0-4.8 C&S: 4.4-5.7 20-25 1.1 ~80,000 TBD 0.99989 1x10 N/A
-4

10 100 1.5 40,000 0.5 0.9999 4x10
-4

Gain instability (%) < 0.1

< 0.1

< 0.2