joshua.freed@LIGO.ORG - posted 16:57, Tuesday 16 June 2026 (90644)
SPI, Pathfinder Install, First hints of efficiency drift in IFO REF
J. Freed,
At 9:18:50 this morning our aligned REF IFO started to fluctuate in efficency. (SPI_REFIFO_Efficency_Oscilation_Start.png) This happened before while building SPI in the optics lab; however, then it was happening contiuously, while now our REF IFO was fine until it started happening.
SPI_REFIFO_Efficency_Oscilation_Start_C.png At the exact same time as when this started, the REF PWR MON fliped to negative power for a split second. (The second time we have discovered negative power). I have no clue to what caused this flip
SPI_REFIFO_Efficency_Oscilation_Start_NC.png I checked other possible causes: (set frequency changes and pico moter movements) but they were minutes before this occured so unlikly to be the cause.
Images attached to this report
