gabriele.vajente@LIGO.ORG - posted 11:11, Monday 24 April 2023 - last comment - 08:48, Tuesday 25 April 2023(68948)
New THERMALIZATION guardian ready for operation
Wrote a new guardian called THERMALIZATION. FOr now it will only change the PRCL gain following a tyrend close to what we measured over past locks.
The plan is that ISC_LOCK will request the "THERMALIZED" state after LOWNOISE_LENGTH_CONTROL, instead of turning on the PRCL UGF servo.
The THERMNALIZATION guardian will transition to "SERVO_PRCL_GAIN" and start increasing the PRCL gain (with 30s ramp) following the equation:
H1:LSC-PRCL1_GAIN = [Gain set in LOWNOISE_LENGTH_CONTROL] * SCALE
SCALE = 1 + 3*(1 - exp(- time / 7800))
After 6 hours the THERMALIZATION guardian will stop adjusting the gain and go to "THERMALIZED"
We still need to test this new guardian at the next lock acquisition
The new hard-coded adjustment of the PRCL gain worked almost correctly. During one lock the initial gain was incorrectly set to 8 instead of 6. This probably happenend becvause the THERMALIZATION guardian read the PRCL1 gain too early after ISC_LOCK changed from 8 to 6.
I added a 10 seconds wait in the main() function of the SERVO_PRCL_GAIN to avoid this problem in the future.