WFC Serial EPER
EPER serial CTE has worsened a bit but is <10% of its parallel counterpart. Discontinuity in Amp A, which was mentioned in ACS ISR 2005-03, is still present. There is some evidence suggesting chip dependence, also mentioned in the ISR.
ACS ISR 2005-03 did not publish coefficients for EPER Serial CTE. Below is the table with the new coefficients. MJD limits are defined such that MJD1 <= MJD < MJD2. There is a hint of discontinuity around the time of -77C to -81C temperature change, especially for WFC2, but a continuous straight line still fits pretty well for now. Their fits are shown in the plots to follow.
| MJD1 | MJD2 | Chip | n | c | p | Notes about MJD2 |
|---|---|---|---|---|---|---|
| 52335 | 58849 | WFC1a | 2.589x10-5 | 6.367x10-8 | -4.265x10-1 | A distant future |
| WFC2b | -3.912x10-6 | 2.852x10-8 | -3.636x10-1 | |||
| a Amps A and B. For A, only <3000e used. | ||||||
| b Amps C and D. | ||||||
CTE vs Signal
WFC1:
WFC2:
Here is the legend:
CTE vs Time
WFC1 (Amp A ~7200e data are shown but not used):
WFC2:
Here is the legend:
