Abstract:
We finally switched the current high-power laser (HPL) to the new NEOLASE HPL, and IFO was locked succeccfulle with the new HPL.
Detail:
I entered PSL room around 11:10 and finished the work around 11:50. For the memo, I write all the processes to exchange the laser;
1. Check that the chiller outside is running.
2. New laser ON
Software:
- ssh -Y 10.68.10.6 (controls)
- las/cer/bin/cerf 10.68.10.8
- set current to 5.5A
Hardware:
- DC power supply ON
- Interlock off
- Master ON
- Power amp ON
3: For old laser
- Block old laser by a dump and reduce the power from 6W to 4W
- Changing optical path by moving 1 axis X-stage located upstream AOM to 0.5mm
4. For PMC lock
- Switching a 15MHz cable to EOM on the new laser
- Change the threshold of TRANS from 0.3 to 1.5
5. IMC lock
- Switching a cable for the slow temperature control at the master laser controller
- Switching a cable for the fast PZT signal at the master head
- Switching a cable for the feedback signal for wideband EOM
Software: Editing IMC.py
- Flip sign for EOM path
- Change MCL gain from 1 to 0.2
In the afternoon, Sako-kun and I adjusted the absolute frequency of the new HPL to two Green lasers. I entered the PSL room from 13:40 to 14:00.
Temperature changed from 21.6 degree to 22.5 degrees. We saw the beat between IR and green X, Y arm PLL was locked at the temperature, and then we disconnected the beat monitor for X green and X arm PLL was looked soon.
Then Ushba-kun tried to lock PRFPMI, and IFO can be locked with RF soon.
However Ushiba-kun reported some strange power drift at the PSL out, instead the PMC transmitted power was stable. This will be investigated tomorrow.