Sheila, Georgia, Jenne, Marie

We modified the DSOFT P loop today:

• We increased the DSOFT P Gain by a factor 3: the -20 dB filter is now turned off, and the loop gain is 10 instead of 30, these changes have been implemented in the guardian.
• We reduced the crossover frequency of L2/M0 by decreasing the M0 LOCK G by a factor 3. This now happens in the guardian in 'DHARD WFS'.

The measurement might be compatible with a reduction of the cross-over frequency, but the phase shift is small compared to what I expected (see figure 1). We might need to add a roll-off in M0 to further reduce the cross-coupling.

We lost lock tonight several times due to dtt excitation, but the good news is that we relocked fast each time to low noise without seeing any oscillation.The increase of DSOFT P gain is probably helping.