Reports until 10:05, Tuesday 11 February 2025
H1 ISC
sheila.dwyer@LIGO.ORG - posted 10:05, Tuesday 11 February 2025 - last comment - 12:38, Wednesday 26 August 2026(82740)
table of PR2 spot position vs measured power in ghost beam

Mayank, Sheila

We now have a number of power measurements at the HAM3 viewport, with corresponding estimates of the beam spot position on PR2 (from  July 2024 78878, yesterday's measurement of 8mW at PR3 yaw -74 urad 82722)

date range PR3 yaw slider value Y2L coefficient spot position on PR2 (in the plus Y direction from the center of the optic) power measured at HAM3 viewport [mW]
July 2018 until July 2024, except for a few days 152 -7.4 14.9 47  
July 5 2024 132     28
July 5 2024 110     19
July 5 2024 100     17
July 2024- Feb 6 2025 100 -6.25 12.588    
May 21st 2024, and Feb 6th- Feb 10th 2025 -74 -3 6 8  
Feb 10 2025 -230 to be measured   to be measured

We used Elenna's new calibration of PRC power 8724 to estimate that we have 2.53kW of power in the PRC beam.

Comments related to this report
sheila.dwyer@LIGO.ORG - 12:38, Wednesday 26 August 2026 (91692)

Louis, Sheila

with PR3 yaw slider at -230, the A2L coefficient was measured as 0.15, 82788.  power at the viewport was logged by Jennie Wright in 82793