camilla.compton@LIGO.ORG - posted 16:42, Tuesday 20 December 2022 - last comment - 13:41, Wednesday 21 December 2022(66500)
Beam posiitons of CO2, RH, and IFO beam updated in HWS channels for ITMs.
Ibrahim and I updated and svn'ed the HWS position channels below. Prompted as Dan noticed that the CO2s could be misaligned compared to the thermalized IFO beam from Elenna's alog 66458 analysis of the ADS moving with CO2X power decrease.
The channels are from alog 65966. We mainly using Mitchell's alog 66099 code to make identifying center positions easier.
- ITMX_BEAM positionwe did by eye as the fit was being thrown off by point absorbers.
- ITMX_CO2 was at a not thermalized CO2 time, I.e if the CO2 drifts while heating up we will not see that drift as I took a time when we only had the CO2 on for ~minutes. The time used for CO2Y didn't have clear images for CO2X which is strange.
- ITMX vertical (Y) CO2 and ITMY X (horizontal) CO2 are both considerably away from the IFO beam.
- I should check how these IFO beam positions compare to the known A2L positions.
| Optic | ITMX | ITMY | ||
| Axis | X | Y | X | Y |
| IFO BEAM | 510 | 470 | 502 | 573 |
| CO2 (annular) | 502 | 430 | 451 | 568 |
| Ring Heater | 512 | 543 | 522 | 512 |
Images attached to this report
Comments related to this report
Comparing the values above to the A2L gains in alog 66171 does not make sence. Even the signs are wrong.
*BEAM POS values calculated using (IFO beam) - (RH) *0.21mm/pixel the difference in values from table above.
Pixel size * magnification= 0.012mm * 17.5 = 0.21mm/pixel
Whole CCD = 0.21mm x 1024pixels = 12.3mm => 215mm of ITM imaged
| Spot is XXmm from the center of the optic at: | FULL_POWER from A2L | BEAM POS from HWS* | |
| ITMX | PIT | 7.5mm | -15mm |
| YAW | 6.3mm | 0.5mm | |
| ITMY | PIT | 4.2mm | +13mm |
| YAW | -4.8mm | -4.2mm | |