40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Tue Nov 17 20:40:08 2015, yutaro, Summary, ASC, Loss maps of arm cavities 
    Reply  Wed Nov 18 11:22:13 2015, yutaro, Update, ASC, Loss maps of arm cavities ETM_PIT_up.pngETM_PIT_up.pngETM_YAW_up.png
       Reply  Fri Dec 4 10:18:33 2015, yutaro, Update, ASS, Offset in the dither loop of XARM vs beam spot shift on ETMX offset-angleETMXPIT.pngoffset-angleETMXYAW.png
Message ID: 11776     Entry time: Tue Nov 17 20:40:08 2015     Reply to this: 11779
Author: yutaro 
Type: Summary 
Category: ASC 
Subject: Loss maps of arm cavities 

In preparation for the measurement of loss maps of arm cavities, I measured the relationship between:

the offset just after the demodulation of dithering loop (C1:ASS-YARM_ETM_PIT_L_DEMOD_I_OFFSET and C1:ASS-YARM_ETM_YAW_L_DEMOD_I_OFFSET)

and

the angle of ETMY measured with oplev (C1:SUS-ETMY_OL_PIT_INMONC1:SUS-ETMY_OL_PIT_INMON and C1:SUS-ETMY_OL_PIT_INMONC1:SUS-ETMY_OL_PIT_INMON)

while the dithering script is running. With the angle of ETMY, we can calculate the beam spot on the ETMY assuming that the beam spot on the ITMY is not changed thanks to the dithering. What we have to do is to check the calbration of oplev with another way to measure the angle, to see if the results are reliable or not.

I will report the results later.

ELOG V3.1.3-