daniel.sigg@LIGO.ORG - posted 12:04, Thursday 01 May 2025 - last comment - 16:41, Thursday 01 May 2025(84224)
Testing photodetectors in HAM1
I was using the RF test input to test the response of the photodetectors in HAM1.
LSC-POP_A, LSC-REFL_A, LSC-REFL_B are working as expected after swapping the cables at the patch panel for Test-Out and RF1.
ASC-REFL_A was working as expected.
ASC-REFL_B showed no response.
ASC_POP_X looks like the RF cables may be switched.
Swapped the coax cables on POP-X and it is working as expected now.
We did flash light tests on all detectors and were able to observe DC shifts on all detectors. LSC REFL_A and POP_A were swapped. This is a wiring diagram error and the in-air d-subs were swapped at the vacuum feedthrough.
We measured the current draw of ASC REFL_A and REFL_B, they are very similar to each other and close to the values measured in the test procedure.
Still no RF transfer functions for REFL_B.