Lock acquisition procedure towards detuned RSE

1
Lock acquisition procedure towards detuned RSE
Start with no DOFs controlled, all optics
aligned. Re-align each 1.5 hours.
ITMy
166MHz
ITMx
13m MC
BS
33MHz
PRM
PO DDM
SP33
SRM
SP166
SP DDM
AP166
AP DDM
2
Lock acquisition procedure towards detuned RSE
DRMI 2arms with offset
Average wait 1 minute (at night, with tickler)
ITMy
166MHz
ITMx
13m MC
1/sqrt(TrX)
BS
33MHz
PRM
T 7
PO DDM
SRM
SP166
SP33
T 7
I
SP DDM
Q
AP166
AP DDM
3
Lock acquisition procedure towards detuned RSE
Scripto-matic
Short DOFs -gt DDM DARM -gt RF signal CARM -gt DC
signal
1/sqrt(TrX) 1/sqrt( TrY)
Discretionary
CARM
CARM -gt Digital CM_MCL servo


DARM
ITMy
166MHz
ITMx
13m MC
BS
33MHz
PRM
PO DDM
SRM
SP33
SP166
SP DDM
To DARM
AP166
AP DDM
AP166 / (TrXTrY)
4
Lock acquisition procedure towards detuned RSE
Reduce CARM offset
Up next
Go to higher ARM power, switch on AC-coupled
analog CM_AO servo, using REFL DC as error
signal. Locks somewhat stable at 85 of maximum
power.
RF control of CARM REFL166 (POX/POY 33 ?)
DARM
ITMy
166MHz
GPR5
ITMx
13m MC
BS
SP166
33MHz
PRM
PO DDM
SRM
SP33
SP DDM
To DARM
REFL
AP166
AP DDM
AP166 / (TrXTrY)
5
Ready for Transition to RF CARM
6
Progress in last 2 months

• Use CARM DC signal to creep closer to full arm
  resonance (signal goes away at resonance)
• combined PRC and arm gain as high as 60, 85 of
  the way to peak, corresponding to offset of 8 pm,
  assuming arm losses of 200ppm (inferred).
• Progress due largely to improvements in loop
  filtering, to obtain more gain and reduce noise
• Also significant improvements in automation of
  lock procedures.
• all DOFs diagonalized (3x3 2x2)
• Lock is lost because of large frequency noise
  (presumably)
• Effort to reduce frequency noise using CM servo
• digital CM servo to MC works well
• analog servo using DC signal seems to work, RF
  under development
• Much effort to reduce frequency noise
• Noise may be coming from in-vac PZTs