Cleaning outside IP cavity, posted by Loïc Amoudry at Optical room about lasers and optics | utilities 
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From 7th january to 11th january.
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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Today with Ronic
For the Temperature fluctuation :
we checked the valves of the tubes bumping water into the chiller from ThomX main water supply, they were |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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Ronic on Friday operated the Amplifier from the Alphanov software, switched it off then turned on the LAL software,
and it worked for 40 min without issues or error appearing,
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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the laser amplifier worked for some days but it ended to a "watchdog" alarm which switches off the amplifier... investigation is ongoing
Ronic
Chiche wrote:
Ronic on Friday operated the Amplifier from the Alphanov software, |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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we have had this new issue (watchdog alarm switching off the amplifier) for several days.
Alphanov mentionned it could come from the input oscillator stability (modelock loss for example).
Today, |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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With Daniele after, we took a readings of the beam with a lens of 750 mm.
From the observed data, we can state that the beam is not completely Gaussian M2 > 1, due to the variation of the ellipticity of the beam
along the focused path |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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This morning,
- with the "Alphanov" software => Central panel => "system" button => Watchdog "Period Max" was at 100ns
and has been set to 200ns. |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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This morning with Daniele, we did a second measurement of the beam profile using a different lens of focal 400 mm.
at a power amplification of 20%
the amplifier stayed on for around one hour and a half with no errors. |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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On Monday 20th of February, Daniele and Viktor took some beam profile measurement data @ 50% of power amplification.
data and analysis can be found in the attached file.
Ronic |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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Yesterday, Guillaume Machinet and Vincent Clet from Alphanov came to fixe some issues with the laser amplifier:
- 1) they fixed the "rep. rate" measurement issue.
previously, the voltage range in which it was possible to detect the correct rep rate (33MHz) was very narrow ~ 50mV. |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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This morning with Victor we took a reading of the beam profile using a 400 mm lens at 70 % and 100 % amplification.
Will process the data and add after
Note : after an hour and half of amplifier on at 70% we increased the power to 100%, and after ~ 10 minutes the amplifier turned off and showed |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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this morning with Manar,
we checked the Alphanov amplifier issue : "The laser has been stopped because its power is too far from the nominal power".
the photodiode voltage measuring the output power has drifted again and then, the estimated output power was wrong, triggering an alarm issue. |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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We took reading of the beam profile of the amplifier without a lens @ 30 cm from the 2nd wedge for amplification percentages
20-30-40-50-60-70-80-90-100 % another additional 3 readings will be taken at different locations for all amplification percentages.
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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due to several "case temperature" issues, I change the "Max case temperature" in the "general config" of the "Alphanov
Software" from 50°C to 55°C.
=> validated by Alphanov. |
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Optimizing lock parameters for stable X-ray production, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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here are the (good) lock parameters used this morning.
for the RF/FPC lock, the 33MHz beating signal used to select the right bucket is 1Vpp
=> beating signal : V0 . sin(phi) with V0=0.5V. |
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Optimizing lock parameters for stable X-ray production, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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Today with Daniele and Alice, we operated to cavity.
we obtained 84kW for 33% of amplifier ratio.
we had to tune the CEP @ -565µm and the FP-cavity alignment. |
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Optimizing lock parameters for stable X-ray production, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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This morning, I wanted to test quickly if the Smaract motors can be used in open loop instead of closed loop or in piezo scan.
the goal is to do very fine steps without to much vibrations (like with piezo scan mode) but with the full motor range (the piezo scan mode
has a very limited range). |
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Optimizing lock parameters for stable X-ray production, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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This afternoon, we scanned the optical table vertically with the hexapod in asynchronous mode to find its optimum position, looking at the X-ray production.
then, we searched for the correct bucket and phase in the bucket thanks to the Kevin script on the 500MHz and the 33MHz phases.
we got relatively easily some stable X-rays. |
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Optimizing lock parameters for stable X-ray production, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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Today, after setting the locking parameters, I got 80kW in the FPC for 33% amplifier ratio after CEP tuning (Smaract CH2 ~ -423.5µm) and alignment.
maybe the alignment has to be improved by some walking procedure.
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Optimizing lock parameters for stable X-ray production, posted by Ronic Chiche at ThomX igloo about lasers and optics | software
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this morning, I did some walking procedure and I got 82kW in the FPC with 33% amplifier ratio (after CEP optimization too).
but when I move the FP cavity motors to adjust the frequency, I cannot keep this power and it is reduced.
could it be we get a stronger correlation between axis than before in the mechanics has more rust than before ? |