Today the TCS system was progressively restarted after the shutdown.
PR CHRoCC
- Suzanne switched on the PR CHRoCC at 10:40 UTC (4.14 V, ramp time: 7200 s).
Ring Heaters
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In the morning, Fabio restarted the power supply of the SR RH. The SR RH was switched on at 11:04 UTC after approval from Antonio.
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The NE and WE RHs were also unreachable. In the afternoon, Fabio went to the end buildings and was able to fix the problem. The RHs remained powered ON; only the process data were unavailable.
CO₂ Benches
Some preliminary actions were performed before switching on the lasers:
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Vincenzo and Nicola checked the correct operation of the chiller system.
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Suzanne opened the acoustic enclosures housing the CO₂ benches to verify that all power meters and thermal cameras were powered on. All devices were ON and appeared to be working properly.
Although the thermal cameras were powered, they were not reachable remotely. We informed the computing team, who recovered the connections.
The TCS Agilis Rot process (controlling the half-wave plates on the benches) was not running --> Franco restored the system.
After these checks, in the afternoon, at around 15:30 UTC, the entire system was switched on again (chiller + main lasers + auxiliary lasers).
An issue was observed on the NI bench: after the restart, the laser output power is approximately half of the pre-shutdown value (see Fig. 1).
Suzanne inspected the optical bench and did not notice any abnormal condition. The reduction appears to come from the laser itself, which is currently delivering about 50% of its nominal power. A possible explanation is a failure of two out of the four RF driver modules. Further investigation is needed.
