TJ, Camilla. CO2Y swapped in alog 65393.
We have re-calibrated the ITMY_CO2_LSRPWR_HD_PD channel by adjusting the "Watts" filter from 13.96 to 9.21 with an offset of 15. Today we measured 45.6W out of the CO2Y laser head with the chiller set at 20.0degC. This is significantly more power than when we installed it, the power jumped up yesterday at 04:08am PDT seemingly with a PZT move. Looking closer at the guardian the temperature increase was due to the laser power increase, it did not cause it.
We removed the beam dumps from CO2 X and Y so now any CO2 power will be injected into the vacuum system. Will need to check and adjust the CO2Y alignment to ITMY using the HWS and periscope picomotors.
It seems to me that the laser power jumped and then the PZT moved in response. The laser head input is at the start of the loop as seen on the TCS screen itself (attached), so I think there was some type of internal mode hop(?) that brought the power up and the pzt moved with the power change. There was also a drop in the amount of current from the power supply by 1.5A at that time, which I think I need to think about more to understand. I haven't found any other stimulus for this sudden laser power increase, at least with me digging through epics. More investigation needed.