richard.savage@LIGO.ORG - posted 11:30, Friday 12 May 2023 - last comment - 16:27, Monday 15 May 2023(69539)
H1 Pcal calibrations updated
DriptaB, TonyS, RickS
The following commands were executed to update the calibrations of the Pcal Tx and Rx laser power sensors at both end stations:
caput H1:CAL-PCALX_FORCE_COEFF_RHO_T 8334.52
caput H1:CAL-PCALX_FORCE_COEFF_RHO_R 10692.3
caput H1:CAL-PCALY_FORCE_COEFF_RHO_T 7157.80
caput H1:CAL-PCALY_FORCE_COEFF_RHO_R 10652.5
These changes increase the calibrations of the Pcal sensors (ct/W) by 0.603 % in response to recent calibration of Pcal transfer standards by NIST and PTB in Germany. Details of the rationale for the update can be found in LIGO-G2300471, slides 13-18.
This change will result in a 0.063% increase in inspiral range (about 0.84 Mpc).
The changes have been accepted in SDF.
There's a typo in Rick's statement This change will result in a 0.063% increase in inspiral range (about 0.84 Mpc). It should read This change will result in a 0.603% increase in inspiral range (about 0.84 Mpc). Where I confirm this with other statements in the aLOG: (a) assuming that he quotes our range at 140 Mpc, and thus the 0.84 Mpc parenthetical above is from 140 Mpc * 0.603% = 140 Mpc * 0.00603 = 0.84 Mpc (b) the statement just prior, saying "These changes increase the calibrations of the Pcal sensors (ct/W) by 0.603 %" and that the math checks out -- that an increase in PCAL force coefficient translates to an increase in detector sensitivity -- based on historical educational material in LHO:52837.