I checked the situation of ASS. I wanted to know how much we are away from the maximum transmittion.
ASS makes the X arm shifted from the maximum transmission. This causes the contrast degraded by ~3%.
We need to fix the Xarm ASS so that it can maximize the transmission and ignor the spot centering at ITMX.
Conditioning before the measurement:
- ASDC offset was removed
- X&Y arm was aligned by ASS
Average transmission: 0.86
Pmax = 1045 +/- 9 cnts
Pmin = 22 +/- 4 cnts
==> Contrast = (Pmax - Pmin)/(Pmax+Pmin) = 0.960+/-0.007
After manual alignment of the X arm (ignoring spot centering):
Average transmission: 0.88
Pmax = 1103 +/- 11 cnts
Pmin = 5 +/- 1 cnts
==> Contrast = (Pmax - Pmin)/(Pmax+Pmin) = 0.991+/-0.002