Camilla Sheila Mayank

Currently QPD Trans A is used for sensing the "INJ ANG" DOF, however we want to use ADS for this DOF.

Getting up the ADS  

1. We dithered FC1 and FC2 in Pitch and Yaw

   	Optics	Freq	Amp
   Pitch 1	FC1	10	10
   Pitch 2	FC2	12	10
   Yaw 1	FC1	6	10
   Yaw 2	FC2	8	10

2. Obeserved these frequency peaks on WFS signal ( H1:SQZ-FC_WFS_A_I_SUM_OUT_DQ   H1:SQZ-FC_WFS_B_I_SUM_OUT_DQ)
3. Demodulate Signal (Modified the ADS inmatrix to choose H1:SQZ-FC_WFS_A_I_SUM_OUT_DQ for dmodulation)
4. Fixing the right demod phase : At the right demod phase one of the demod quadratures (Q) will go to zero while the other quadrature (I) will respond to the beam spot movement.
   • This is done by continuoulsy changing the beam spot location* and monitoring the change in I and Q signal. From this change we estimated the phase offset required to bring the phase to right value.
     • If both I and Q move in same direction by approximately same amount the are off by 45/135 degree.
     • if only one of the quadratures move while the other remians constant the we are closer to the righr phase.
   • *Note: We changed the P2L/Y2L coefficient of FC1/FC2 , which amounts to changing relative position between the beam and the center of optics motion.

The ADS was running and we had the error signals. However we ran out of time and hence could not close the loop. We reverted everything to the previous state. We will try to repeat this during next commissioning time.