46.1 Effect of Decontaminations

Temporarily restore UV transmission and reduce contaminations. See "Flatfield Anomalies" on page 46-7 below and "Photometry" on page 46-9 for corrections to apply to the data to compensate for the decons; note, too, that synphot can be used to determine and apply a contamination correction (use the CONT keyword in the OBSMODE; see WF/PC-1 ISR 96-02 ).

**WF/PC-1 Decontamination Events**
Date	DOY	Activity
1990	Dec 31	365	Telescope safes (FGE 3 bit flip); UV flood
1991	Jan 2	002	Mini-low-temp decon
Jan 26	026	De-ice decon (-82C)-failed to remove daisies
Jan 28	028	Mini-low temp (-20C)-removed daisies, created measles
Jan 29	029	Low-temp decon (-15C)-removed measles
May 2	122	PSEA hardware safe mode, CCDs at -35 for 80 hours, created measles
May 8	128	Hot-junction decon (+12C)-removed measles
Jul 3	184	WIDLE turned WFC TEC off for 7 hours WFC reached -25C, created measles
Jul 5	186	Flash decon (+6C)-removed measles
1992	Feb 3	03/4	Flash decon-restored UV transmission, removed scattering but made persistent measles
Feb 4	035	Flash decon (same as day 034)-p.measles still present
Mar 3	063	Hot junction decon-p. measles still present
Mar 8	68	Flash decon-persistent measles still present
Aug 7	220	Flash decon (CCDs +3.5C to +8.5)
1993	Aug 2	214	Modified flash decontamination