Reports until 08:36, Thursday 31 December 2015
H1 General
corey.gray@LIGO.ORG - posted 08:36, Thursday 31 December 2015 - last comment - 09:13, Thursday 31 December 2015(24582)
Transition to DAY Shift Update

TITLE:  12/31 DAY Shift:  16:00-00:00UTC (08:00-04:00PDT), all times posted in UTC     

STATE of H1:   Down & alignment/locking investigation by Kiwamu

Outgoing Operator:  Ed

Quick Summary:

Kiwamu & Ed ran into issues with the INPUT ALIGN section of the Initial Alignment.  Kiwamu mentioned it could be related to the AS_Air photodiode.  (Even though we can't get to INPUT ALIGN, the AS Air spot looks nice [no higher order modes or jumps when flashing AND the IR Xarm flashes have been up to 1.0---so, it looks good...but no INPUT ALIGN).  Current plan is to skip the INPUT ALIGN section of Alignment and try locking.

Additional Notes:

1)  And if you are familiar with Initial Alignment issues of late, you will remember that lately we have been skipping the Dark Michelson portion of Initial Alignment....and this state also uses AS_Air.  So this sounds suspicious....

BUT, 

2)  SRC state of Initial Alignment also uses the AS_Air PD, and we were able to get SRC with no problem.  Suspicious indeed!

Currently waiting for DRMI to lock.

Comments related to this report
corey.gray@LIGO.ORG - 09:13, Thursday 31 December 2015 (24584)
Link

Back To Observing at 17:10UTC (9:10amPST)

Only SDF Diff was:  Dark offset for AS_AIR was Accepted (from -75.0 to -80.0).

Notes on Guardian steps:

  • The AS_AIR photodiode is used from Guardian steps:  RF_DARM --> DC_READOUT (we focused our attention here to see if there were any issues due to the AS_AIR pd, but did not notice anything.  So we made the transition from RF (AS_AIR) to DC (DCPDs of the OMC) with no issues--YES!!
  • We did hang out at ENGAGE_ASC_PART3 for about 10min to wait for the ASC signals to converge.
  • Engaged ISS 2nd Loop by hand.  Also took REFSIGNAL from -2.00 to -2.02 to raise the Diffracted Power.
  • Then went to NLN with no issues.
  • Range has been hovering around 77Mpc 15min into lock.