TJ, Jason, Camilla, Fil.

WP11612, FRS25384, swapping because current CO2X laser was slowly deteriorating, details in 75249.

Removed: Access 50LT 20706.21015D. Installed 20306-20419D, which was refurbished/re-gassed in March 2020. Table layout: T1200007.

• On Tuesday 23rd:
  • Checked polarizers on both CO2X and CO2Y (pictures) and spares were fine after issues at LLO (FRS30220). Will update FRS with details. 
  • Added labels to RF cables and water tubes on CO2 laser and RF driver.
  • Scribed current position of CO2 laser and photographed.
• On Wednesday 24^th AM:
  • Placed beam dump in front of periscope.
  • Remembered L1 has some damage on lens, caused by the plastic lens ring, photo. In future we should use metal lens rings.   
  • Turned on CO2 laser.
  • Check position on FLIR, with no mask, central and annual masks (needed to turn on FLIR – power supply inside enclosure).
  • Checked beam is going though all irises with beam card kit and FLIR one camera. Pictures
    • On masks: beam slightly high/masks low
    • On irises – beam a little low, but well centered with masks in.
    • Will not adjust irises 
  • Turned off: chiller, power supply, RF and power supply in mechanical room mezzanine,  AA chassis
  • Disconnected water lines (outside CO2 table). Drained table lines with gravity and wet-vac.
    • The small on table water lines have a lot of old contamination in them, photos of RF driver and CO2 lines, comment added to FRS10612 so we can think about replacing these lines post O4. 
  • Disconnected all cables and water pipes to CO2X/RF driver and removed laser and RF driver. 
  • Installed new CO2 laser (needed to move back foot back one set of bolt holes and turn water connections around 180deg). 
  • Installed new RF driver after Fil reattached it's electrical plug
  • Reconnected all cables and water pipes (expect table to main line connection). Photos of installed laser and RF driver.
  • Powered on CO2X chiller (had been turn off in medm so usually wouldn't turn on but it did)
  • The CO2X water pipe coming from the mezzanine leaked under the high pressure (as not yet connected to table), spraying water onto the cable trays above SQZ0/SQZT7 and SQZT0. 
  • Betsy initiated stop work M2400022, we transitioned to laser safe and Fil disconnected electrical connections. 
  • Richard, Fil, Jason and TJ dried the area as best they could. We see no sign of water inside SQZT0. 
  • Will reassess next steps on Thursday 25th. 

Still to do after the CO2X cooling line issue is solved:

• Refill table with water and reconnect to chiller.
• Turn on laser in PWM mode for low power realigning.
• Realign laser to irises and FLIR camera using M1 and PM1 mirrors
• Measure power out of laser head using S322C
• Check alignment to power meter and masks
• During commissioning time: spend ~2 hours realigning in-vac using HWS and periscope picos.