Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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on Monday morning 7/11, we tried to restart the Alphanov amplifier which was not turned on since end of april 2022, but it didn't start.
we did a standard "turn ON" procedure :
- check the safety button on the front panel (which has to be released). |
Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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I just tested the fuse inside the black ON/OFF switch on the rear panel => it is OK ! :-(
Ronic
Chiche wrote:
on Monday morning 7/11, we tried to restart the Alphanov amplifier |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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The laser amplifier controller has been sent yesterday and received today by Alphannov.
they should do the assessment quickly...
Ronic |
Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics 
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Today, I did a Teams meeting with Guillaume.
He didn't see any problem with the controller.
normally, the controller will be shipped to the lab tomorrow. |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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Yesterday, we received the controller back from Alphanov
and I tested it immediately in the optical room.
if the software is properly talking to the controller, everything works normally. |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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FYI : to access special menus on the Alphanov software,
login : "Administrator"
pwd : no password |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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the present situation is :
Guillaume asked me to disconnect the "Laser head" cable from the pump diode module, installed on the optical table.
on the pump diode module, the connector has several small pins and 3 larges pins : A1, A2, A3. |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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Guillaume and Julien Bour from Alphanov will come on wednesday 24/07 to have a first look and check the amplifier.
to prepare their intervention, I tested this morning the OneFive oscillator : it's still working at 33MHz.
and we have ~5mW in the LAL software without the EOM. |
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Alphanov amplifier issue, posted by Ronic Chiche at ThomX igloo about lasers and optics
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picture of the connectors used to carry signals between the amplifier pump module and the rack under the table.
DB13W3 standard has been used to carry high current on the 3 dedicated pins:
https://en.wikipedia.org/wiki/DB13W3 |
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Alphanov amplifier compressor's CVBG thermal images, posted by Ronic Chiche at ThomX igloo about lasers and optics
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last Friday with Manar, we took some thermal images of the Alpnavov compressor box.
I post a small document to summarize some points :
- the 2 mirrors used to make the CVBG injection are polarized thin-film mirrors... thus sensitive to the beam polarization. |
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Alphanov amplifier compressor's CVBG thermal images, posted by Ronic Chiche at ThomX igloo about lasers and optics
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last Friday with Manar, we took some thermal images of the Alpnavov compressor box.
I post a small document to summarize some points :
- the 2 mirrors used to make the CVBG injection are polarized thin-film mirrors... thus sensitive to the beam polarization. |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics
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today with Manar, we brought everything to make the profile measurement.
the chiller was in error because of the water level : we filled it in.
! warning ! there is no alarm signal, only a message on the screen. |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics
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yesterday morning with Manar,
1) we fixed the threshold level of the laser input signal which makes the measurement of the repetition rate.
(if the rep rate is not measured properly, the amplifier safety interlock stops immediately the amplification). |
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Alphanov amplifier beam profile measurement, posted by Ronic Chiche at ThomX igloo about lasers and optics
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this morning with Manar,
- we checked first the chiller problem.
the fluctations of +/-2° around 25°C are still there. |
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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
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this morning with Manar,
- we fixed the chiller problem (+/-2°C fluctuation around the set temperature value = 25°C).
we opened and closed several times the water valve of the primary circuit to remove air bubles => no effect on the temperature variations. |
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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 |