This afternoon, we performed several checks before starting the HWS-DET acquisition with the NI RH ON.
As a first step, we checked the HWS-DET acquisition and encountered an issue with the MATLAB version called by the Python code of the acquisition software. Giulio solved the problem by updating the acquisition code to make it compatible with the MATLAB version 2023.
Now the command to launch the acquisition is:
./hwsAna2022_R2023a.py -d/r/l DET
In parallel, Fabio went to the Central Building to switch on the power supply of the NI and PR RHs.
At this point, we prepared the ITF for the measurement. After being locked in CITF with the additional loop on the NI MIR engaged by Paolo, the ITF was set in NI single bounce.
The HWS-DET illumination is shown in fig. 1. The voltage of the SLED has been settled to 1.45 V.
14.41 UTC: HWS ACQUISITION START (20260831T1641)
14.58 UTC: NI RH ON at around 10 W (V=19 V)
16.49 UTC: NI RH OFF (WAVEFRONT #42)
The RH signal was clearly visible in the HWS map (see Fig. 2).
The HWS beam appears to be displaced with respect to the center of the mirror by approximately 1 cm and 2 cm along the two directions..
To verify the alignment of the NI CO₂ actuators, I switched on the NI CH at 17.12 UTC.
An example of the wavefront map with CH ON is shown in fig. 3. The CO₂ actuators and the RH appear to be well aligned in the horizontal direction, while the CH appears to be slightly lower than the center of the mirror in the vertical direction. However, I would like to repeat the measurement with the CH, since this measurement was performed after several hours in SB.
At the end of the measurement, I closed the NI CH flip mirror (19.38 UTC).
Paolo will disengage the additional loop later this evening.
The North arm will most likely need some time before it can be relocked.