francisco.llamas@LIGO.ORG - posted 14:12, Tuesday 25 March 2025 (83550)
Pcal XY comparison investigation - Beam back to center
FranciscoL, TonyS, MattT, RickS
On Tuesday, March 25, we reverted the PCALX lower beam to its nominal center. We expect to see a change of 4 HOPs in \chi_XY -- returning to the value it was two week ago.
Target was placed with a 33 degree offset as seen on the first attachment (TARGET_ON -- featuring a responsible scientist, wearing laser goggles). Each individual beam voltage values, as found, were very similar to the values recorded at the end of the move done last week.
The following table shows the voltage values as read by the Keithley voltmeter we use during the procedure
| Step | Comment | Readout [V] |
|---|---|---|
| 1 | Both beams - target off | 3.379 |
| 2 | Both beams - target on (as found) (BEFORE_MOVE) | 2.937 |
| 3 | Lower beam after actuation | 1.395 |
| 4 | Both beams - target on (AFTER_MOVE) | 2.903 |
| 5 | Both beams - target off | 3.394 |
The IFO has not regain lock at the time of writing this alog which limits further observations from this move.
Images attached to this report
