TJ, Camilla, Fil.
Started shortening path length of TCS CO2X laser on TCSX table by ~360mm to account for increased in-vac path length from table move. WP 10116
Overall will move the masks, BS1, lens, mirror and one iris (labeled 'output optics' on T1200007) , plus the eye-safe alignment laser setup. We will be careful to keep the alignment of iris and the alignment laser.
We have:
1. Used the eye-safe alignment laser to add an additional iris 360mm in -x- this will become the first iris.
2. Blocked CO2X beam path before periscope.
3. Turn on CO2 laser voltage supply in mechanical room mezzanine. Fil turned on TCSX 100V in CER upstairs after TJ plugged high voltage into the table (we will later need to add tape to cover the gap in enclosure).
4. Turn CO2X laser on via chassis in LVEA and medm. This didn't work. Fil helped and realized we needed to plug in the VP IR sensor. Still we were reading negative powers at the laser. We stopped for lunch here thinking that we were missing something but actually we could turn the laser on, just the power readback was negative. Maybe there is still filter problems after the tcs computer / Beckhoff changes. Tagging cds- will investigate more Monday. The pzt seemed also to not be keeping the laser power stable.
5. Checked CO2 is still co-aligned with irises.
6. Turned on FLIR laptop and photographed positions of beam with both central and annular masks - this will help us realign the masks later. Moved central heating mask but didn't finish aligning.
7. Powered down CO2 laser via medm and chassis, left mezzanine power supply on. To be continued next week.
TJ, Daniel, Fil, Camilla
With Daniel’s help we found that the h1tcscs ADC0 for TCS CO2X was outputting all zeros while CO2Y outputs were real numbers. Daniel suggested checking everything was plugged in at the rack. We found the Anti-alias chassis (D1300282) for CO2X off so we turned it on. We saw a little smoke come out with a slight plastic burning smell so turned off the the chassis quickly. We also turned off CO2Y chassis which isn't needed now. Fil looked at the CO2X chassis and found a broken op-amp which he will replace and retest in the coming weeks. In the meantime we can continue by using the CO2Y chassis but will wait until the next laser-hazard opportunity.
TJ, Camilla
Yesterday Fil repaired and replaced the TCSX AA chassis (61051) and TJ and I confirmed that the medm read backs now made sense.
We moved both central and annular masks -360mm in -x and aligned to their previous positions on the FLIR. Starting beam positions of FLIR for central and annular. Current positions for central and annular.
The beam on the FLIR looked not uniform, brighter higher up. We then found:
This suggests something got moved downstream of the masks. I haven't worked out how only one movememnt would cause th beam to get high on FLIR and low on the iris.
It's likely we didn't noticed this when checking alignment when starting and in July if we used the central mask to see the beam. Last alignment alog 43024 shows much cleaner mask photos.