40m
QIL
Cryo_Lab
CTN
SUS_Lab
TCS_Lab
OMC_Lab
CRIME_Lab
FEA
ENG_Labs
OptContFac
Mariner
WBEEShop
|
40m Log |
Not logged in |
 |
|
Wed Apr 21 19:28:03 2021, Anchal, Update, PSL, PSL/IFO recovery
|
Wed Apr 21 19:43:20 2021, Koji, Update, PSL, New HEPA speed control 
|
Thu Apr 22 14:41:55 2021, Chub, Update, PSL, New HEPA speed control
|
Fri Apr 23 18:00:02 2021, gautam, Update, PSL, HEPA speed lowered
|
Fri Apr 23 19:26:58 2021, Koji, Update, PSL, HEPA speed lowered
|
Fri May 14 17:45:05 2021, rana, Update, PSL, HEPA speed raised
|
Tue May 18 00:52:38 2021, rana, Update, PSL, HEPA speed raised
|
Tue May 18 20:26:11 2021, rana, Update, PSL, HEPA speed raised
|
Thu Apr 22 15:15:26 2021, gautam, Update, PSL, PMC transmission
|
Thu Apr 22 15:34:54 2021, Anchal, Update, PSL, PMC transmission
|
|
Message ID: 16068
Entry time: Wed Apr 21 19:28:03 2021
Reply to this: 16069
16076
|
Author: |
Anchal |
Type: |
Update |
Category: |
PSL |
Subject: |
PSL/IFO recovery |
|
|
[Anchal, Koji]
Removed the top sheet
- Opened first from the door side so that any dust would spill outside.
- Then rolled the sheet inward to meet in the middle.
- Repeated this twice for the 2 HEPA filters.
Removed the sheets on the table
- Lifted sheet up making sure the top side face outside always.
- Rolled it sideways halfway through.
- Cut down the sheet vertically.
- Slided the doors to the other side and rolled the remaining half.
- On the door side, the sheets above the ALS optics were simply lifted off.
Restarting PSL
- Turned on the HEPAs at the max speed
- Switched on laser to jsut above the threshold
- Before the 1st eom, power was 20mW
- After the EOM/AOM, 18mW. So about 90% transmission through all polarizing optics.
- We saw the resonances of the PMC but could not lock it even with highest gain available (30 dB).
- Increased the input power to PMC to 100mW
- Locked the PMC at 30dB gain
- The transmitted power was ~50-60 mW. (Had to use power meter suspended by hand only.
- The right before the IMC (after the 2nd EOM) 48mW. So none of the alignment was lost.
- Opened the PSL shutter.
- We were able to see IMC reflection signal.
- We were also able to see IMC catching lock as the servo was left ON earlier.
- Switched off the servo.
- Decided to increase the power while watching PMC Trans/Refl and IMC REFL
- Injection diode current to innolight was increased slowly to 2.10A. Saw a mod hopping region aroun 1.8A.
- We recovered the PMC Trans >0.7 V.
- PZT was near the edge, so moved by one FSR.
- The PMC refelction signal is still shown in red at around 48 mV.
Back to control room
- IMC was locked almost immediately by manually finding the lock while keeping IMC WFS off to preserve the offsets from yesterday.
- Then switch on IMC WFS. Working good.
- Then unlocked the servo and switched on IMC Autolocker. Lock was caught immediately.
Decided to start locking the arms
- The arm transmissions were flashing but at 0.2~0.3 level.
- Decided to adjust TT1 and TT2 Pitch and Yaw to align the light going into the arms.
- This made TRY ~0.6 / TRX ~0.8 at the peak of the flashing
- Locked the arms. (By switching on C1:LSC-MODE_SELECT which engages all servos).
- Used ASS to align Yarm then align Xarm. Procedure:
- Sitemap > ASC > c1ass
- Open striptool to look at progress. ! Scripts YARM > striptool.
- Switch on ASS. ! More Scripts > ON
- Wait for the TRY to reach to around 0.97.
- Freeze the outputs. ! Scripts > Freeze Outputs.
- Offload the offsets to preserve the output. ! More Scripts > OFFLOAD OFFSETS.
- Switch off ASS. ! More Scripts > OFF
- Repeted this for XARM.
- At the end, both XARM and YARM were locked with TRX ~ 0.97 and TRY ~ 0.96.
|