this morning, the computer was restarted and I had to launch all the applications.
no problem except the powermeter for which I had to do a power switch OFF and ON remotely.
the chiller was in error and I had to restart it also.
the air temperature seems to be not properly controlled (see the picture)
one can see a constant temperature drop from Tuesday 9 April 10:30am.
it seems the water cooling is also not working properly as I saw the laser amplifier temperature (Temp Amp 1) increased constantly during the run from 24°C to 30°C (in 30 mintues).
=> it's not normal, it should be regulated at 25°C !
I got 89kW in the FP-cavity with 33% of laser amplifier ratio after tuning the CEP and the alignment.
OC/OP/OCH.01-MOT06 roughly at position -782 000 steps.
CEP motor = -425µm
the OC/OP/OCH.01-MOT03 is still faulty => to be fixed by Kevin.
| Ronic Chiche wrote: |
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this morning, I had to restart the chiller. Temp Amp 1 is at 27.5°C after having started the amplifier at 33% ratio.
I removed the 100kohms resistor on the Transmission channel, on the scope (now, it is 1Mohms), to get more sensitivity.
the air temperature is around 21°C and is stable during the last days.
I don't see any power coming from the amplifier despite it is at 33%... I think the MPS prevent us to work and the amplifier shutter is blocking the beam.
I will send an email to Sophie to check that point.
EDIT : Kevin showed me how to acknowledge the error on the MPS
=> go to "Detail" and then acknowledge the "vacuum error".
I saw the FP-cavity resonances but I didn't have time to optimize them as the water temperature is still too high and the chiller is not working good enough.
=> the amplifier did a safety stop.
one needs to wait this issue is fixed.
OC/OP/OCH.01-MOT06 at position -790 000 steps.
CEP motor = -300µm but far from the optimum CEP position.
| Ronic Chiche wrote: |
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from now on, the transmission factor for calculating the FP intra cavity power is 1/1.75ppm ~ 570 000 (changed in the Powermeter software)
this morning the temperature of the water cooling circuit is still very high said Sophie, and the laser amplifier temperature "Temp Amp1" is at 29°C instead of ~23-25°C
then, when I start the laser amplifier, it stops rapidly with a warning error.
I will check the chiller status as the Dalkia should fix the water temperature problem at some time (Sophie + Alice working on this point)
the air temperature in the bunker is back at 19.5°C from last Friday afternoon and is stable at less than 0.5°C.
after restarting the chiller, the "Temp Amp1" is now at 25°C before starting the power in the amplifier, it rises at 28.5°C after some minutes
I found the resonances with the motor OC/OP/OCH.01-MOT06 at position -783 460 steps.
and I had to tune the CEP to get the maximum resonances at -198µm.
with the new transmission factor, I got almost 90kW for 33% laser amplifier ratio after a simple alignment procedure.
the motor OC/OP/OCH.01-MOT03 is sill in error.
| Ronic Chiche wrote: |
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This morning, I locked again the FP-cavity at more than 50kW with 33% of laser amplifier ratio.
the temperature is measured today at 20.5°C despite the fact the air conditionning is still OFF.
the temperature, rising from 18°C, started monday at 11AM roughly.
maybe, the difference comes from the external doors of the Igloo which have been closed recently ? to be confirmed.
as the temperature is measured inside the airflow housing, all the powered equipements are disspating some heat, rising the inside temperature compared to the bunker temperature.
EDIT : Sophie Chance told me the water temperature cooling of ThomX was defective... the water temperature went to 29°C ! it is being fixed by Dalkia.
careful, we don't have a temperature measurement of the water going to the chiller...
to find resonances, I moved the OC/OP/OCH.01-MOT06 motor from position -770 000 steps to position -788 600 steps which corresponds to ~100µm !
it can be explained by the temperature change and also because during the lock last week, I let the MOT06 motor in position after the cavity was at 50kW.
I had also to change the CEP motor position from -170µm to -420µm and to do some alignment (with walking procedure).
accessing the motor OC/OP/OCH.01-MOT03 from the ATK panel, produces an error : "connection to device failed"... to be solved by Kevin ?
| Ronic Chiche wrote: |
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This morning with Daniele, we operated the FP-cavity to be sure there is no issue due to the Linac section changing operation :
- opening/closing the valves due to air pressure break down
- opening/closing the bunker roof
- large temperature change
- etc...
the temperature in the bunker dropped to 18°C instead of 21.5°C, so we had to do some FP-cavity alignment.
but after obtaining resonances and changing the CEP, we got more than 50kW for 33% of amplifier ratio => OK !
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