camilla.compton@LIGO.ORG - posted 14:20, Wednesday 20 April 2022 - last comment - 14:55, Thursday 21 April 2022(62660)
Comparing HWS ITMY images with RH on and off.
Monday's 2022-04-18 evening locks without RH, vs with 0.68W RH that was turned on 1 hour before lock.
| ITMX | ITMY | |
|
Lock with No RH
|
IMAGE | IMAGE |
|
Lock with with 0.68W/seg RH
(turned on 1 hour before lock)
|
IMAGE | IMAGE |
Lock with No RH = 2022-04-19 2:36 UTC 1334370978 (locked at 50W for 50m)
Lock with with 0.68W/seg RH that was turned on 1 hour before lock = 2022-04-19 04:40 UTC 1334378418 (locked at 50W n for 50m)
Ref 2022-04-19 01:25 UTC 1334366718
Friday night 1.7W/seg RH: Note that these ring heater settings were probably too hot and didn't help the IFO alog 62642. You can see the the ring heater quickly flattens the curvature of ITMY.
ITMY:
Image of Cold IFO vs Hot IFO with no ring heater.
Image of Cold IFO vs Hot IFO with ring heater on.
Image of Hot IFO with no RH vs Hot IFO with RH on. Also attached a film of the ring heater being turned on while the IFO is locked. (From 23:18 to 00:28 with 19:00 reference.)
IFO cold + RH cold (2022-04-15 19:00 UTC 1334084418)
IFO hot (50W input for 4hours) + RH cold (2022-04-15 23:18 UTC 1334099898)
IFO hot (50Winput in for 5hours) with RH hot (1.7W/seg for 45mins) (2022-04-16 00:28 UTC 1334104112)
ITMX:
There is an offset in spherical power due to realignment on Friday everning (alog 62641) and only turned on at 00:04 UTC. Cannot get an image of before the RH was turned on)
Image of Cold IFO vs Hot IFO with warming ring heater.
Image of Hot IFO with warming RH vs Hot IFO with RH on. Also attached a film of the ring heater being turned on while the IFO is locked. (From 00:04 to 00:28 with 19:00 reference.)
IFO cold + RH cold (when RH turned off after 4hours Monday AM 2022-04-18 19:00 UTC 1334343618)
IFO hot (50W input for 4hours) + RH warming (1.7W/seg for 20mins) (2022-04-16 00:04 UTC 1334102658)
IFO hot (50Winput in for 5hours) with RH hot (1.7W/seg for 45mins) (2022-04-16 00:28 UTC 1334104112)
Images attached to this report
Non-image files attached to this report
Comments related to this report
Attaching more helpful movies and an image of all the the RH vs no RH images in one. See attached.
All images/videos have the same reference and IFO locked at 50W. Only difference is the 0.68W/seg RH turned on to both ITMY and ITMX 45 minutes before the "with RH" plots powerup.
It is interesting that the RH on ITMY makes the optic very flat where the beam is. But ITMX even with the RH on, the point absorbers give the optic have a positive curvature.
Times using:
Lock with with 0.68W/seg RH video for ITMX, ITMY. 2022-04-19 03:31 UTC 1334374278 - 04:40 UTC 1334378418 RH turned on 45minutes before we are at 50W so still warming up.
Ref 2022-04-19 01:25 UTC 1334366718 Both locked at 50W in.
Images attached to this comment
Non-image files attached to this comment
Gerogia reminded me that we are turning on the CO2 ITMX laser to 2W annular mask when we power up past 10W and off when we loose lock. Alog 62626.