At 17.42 LT the ITF has been locked in low Noise 1 with TCS ON (Pin/out=[450-900]mW on the NI; Pin/out=[200-400]mW on the WI). We waited for the steady state of the YAG thermal lensing before starting the DAS tests (19.31 LT).
We applied the same powers of the STEP 6 during the shift of 14th August (Pin/out=[350-700]mW on the NI; Pin/out=[200-400]mW on the WI; see entry 42442) since we were not sure of the increase of 56 MHz because the signal was affected by large fluctuations.
The measurement performed tonight confirmed the increase of the 56 MHz sideband gain already observed in the previous shift and also an improvement of the dark fringe (see figure 1).
We were forced to stop the measurement for 3 hr because of the earthquakes in Molise and Japan (see operator report entry).
At 22.22LT a new stable lock has been achieved. We started a new measurement, STEP 7, by applying Pin/out =[100- 200]mW on the WI and Pin/out=[350-700] mW on the NI.
A slightly increase of the gain has also been observed.
Thus we leave the ITF with these DAS powers.
