From: Alan Weinstein [ajw@hep.caltech.edu]
Sent: Thursday, July 14, 2005 6:43 PM
To: 'Alan Weinstein'
Cc: 'Alan J Weinstein'
Subject: Rob's tutorial on IFO locking

Hi,

Here are my notes from Rob's tutorial on IFO locking.

1) Start with the PSL locked, ~ 1.5 watts at the periscope.

2) With MC locked, the transmitted power
(RFAMPD_DCMON on the LockMC screen) should be ~ 1.6.
If it's < 1.4, check that the MZ REFL power is < 1.2,
else, relock the MZ and then the MC, using
C1IOO_LockMC.adl.

C1IFOconfigure.adl.

C1LSC.adl

C1IFOALIGN.adl

3) Align the ITMS and TMs:
   - turn on ETMs, lock each arm.
   - alignXarm (~ 2 min)
   - alignYarm (~ 2 min)

4) Align PRM:
   - Restore PRMI configuration, which coarsely realigns the PRM
     (and misaligns the ETMs).
     PRMI is controlled with PRCL=SP33I, MICH=SP33Q
   - run alignPRM (~ 2 min)
   - SPOB (PD12_I) should be > 125.

5) Align SRM:
   - restore DRMI  (PRCL=SP33I, MICH=SP33Q, SRCL=PO199)
   - align SRM by hand, minimizing fringes at AP

6) Adjust PO199 demod phase, if necessary

7) Check the DD signals:
   - run scripts/c1/c1_aqstep to hand off signals
     (PRCL=SP33I->SP133; MICH=SP33Q->AP133; SRCL=PO199)

8) Bring in the arms
   - Restore ETMX, ETMY on IFOAlign.adl screen.
   - carrier & sidebands will flash in arms, causing loss of DRMI.
   - run scripts/c1/c1_detdown to ramp down from 
     detection mode to acquisition mode.
     Wait a few minutes for all 5 DOFs to lock up.
     (PRCL=SP33I, MICH=SP33Q, SRCL=PO199; 
      XARM=1/sqrt(TRX); YARM=1/sqrt(TRY); )
   - run scripts/c1/c1_aqstep to hand off signals
     (PRCL=SP33I->SP133; MICH=SP33Q->AP133; SRCL=PO199;
      DARM=f(TRX,TRY)->AP166Q; CARM=f(TRX+TRY). )
   - Everything is now under RF control and zero offset,
     except CARM with is under DC control, with offset.
   - Try to reduce offset and hand off to SP33 or SP166.

Alan J Weinstein
California Institute of Technology
256-48 Caltech
Pasadena, CA 91125
ajw@caltech.edu
626-395-6682
fax: 626-795-3951