Reports until 16:46, Tuesday 15 November 2022
H1 TCS
camilla.compton@LIGO.ORG - posted 16:46, Tuesday 15 November 2022 (65804)
EX HWS Looking for ITM reflection, optimum camera position

Ross, Mitchell, Camilla. WP 10813. 

  1. Measured the power on the HWS path (Drawing D1800270). Measured 1.37mW out of SLED (when set to maximum), 0.27mW in path before M4. This is a lot of power lost on table. 0.57mW is transmitted though HWS-BS and dumped, some reflected off HWS-POL and after the measured 0.27mW more is reflected off ALS-M11 (not measured). 
  2. Looked for HWS beam movement from ETMX and ITMX movement. We dithered EMTX and ITM PIT and YAW in turn and saw some coupling into the HWS signal for all, this isn't ideal. Using awggui with Gain 50 and  f = 0.1Hz into channel H1:SUS-{ETMX}_M0_DITHER_{Y}_EXC. I will attach videos and trends. 
  3. We dithered ETMX as above and moved the HWS CCD camera 1" either way to see if we were at the imaging point. Looked at HWS PRISM values and took new references between each movement. Didn't really see much of a change, could have moved it further but we ran out of time. Distance measured between CCD camera face and steering mirror. Left it at the original position and centered beam on CCD with steering mirror.
  4. Camera and time
    Dither ETM
    Prism X (e-6)
    Prism Y (e-6)
    Total pixel power (e-6)
    6.5" 11:59am (Original)
    		 P
    4
    13
    Slight change
    6.5" 12:02  (Original)
    Y
    10
    1
    Changing
    5.5" 12:14
    		 P
    3
    17
    0.7
    5.5” 12.11
    		 Y
    10
    1.5
    0.8
    7.5” 12:19
    P
    3
    15
    0.6
    7.5” 12:21
    Y
    10
    1
    0.5
    6.5" 12.31  (Original)
    P
    5
    12
    0.4
    6.5" 12:29  (Original)
    Y
    6.7
    2.5
    1