Increasing the FP-cavity power , posted by Ronic Chiche at ThomX igloo about lasers and optics 8x
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Last Friday, we tried to increase the FP-cavity power by just increasing the amplifier ratio from 35% to 70%.
It took a bit longer than expected because it started with the surprise of finding our entire setup powered off…
The power had tripped, and the switch that allowed us to remotely reset the power supplies had been damaged. |
Increasing the FP-cavity power , posted by Ronic Chiche at ThomX igloo about lasers and optics
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today with Alice and Daniele,
we checked the distance of the optical setup :
from the amplifier output (the fiber output) to the 2nd lens (+200 mm) : |
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Increasing the FP-cavity power , posted by Ronic Chiche at ThomX igloo about lasers and optics
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new power increase after alignment of the waveplates and iris.
amplifier ratio (%) => FPC cavity power (kW) => FPC cavity coupling (%) => Vr unlock (mV)
33 => 98 => |
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Increasing the FP-cavity power , posted by Ronic Chiche at ThomX igloo about lasers and optics
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I installed a stronger optical filter on the reflection photodiode and loaded it on 1kOhms.
70% amplifier ratio => 575 mV => 575 µA => no more photodiode linearity issue
amplifier ratio (%) => Vr unlocked (mV) |
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Increasing the FP-cavity power , posted by Ronic Chiche at ThomX igloo about lasers and optics
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this morning with Daniele, we set the amplifier ratio to 33% => 97kW
then, we set the amplifier ratio to 50% => 124 kW (position of the diffuser on Axis 18 : +11775)
we changed the waveplates axis => no effect |
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Increasing the FP-cavity power , posted by Ronic Chiche at ThomX igloo about lasers and optics
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Last friday, with Daniele, we did some realignement on the 2nd CVBG of the compressor : the beam shape seems better, now.
this morning, we checked that the injection path (periscope and injecton mirrors) is not sensitive to the polarization state of the beam.
we checked also the power at the input of the FPC for 70% amplifier ratio : 40W ! |
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removing of the M1 mirror, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | vacuum
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after trying to increase the power and after moving S3 to try to change the size of the beam on the mirrors, the FPC power suddenly droped.
so, we need to remove M1 to check if it has been damaged.
we placed an iris in reflection of the FPC to keep the alignment for the new mirror M1. |
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removing of the M1 mirror, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | vacuum 6x
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this morning, with Daniele, we took some images of the M1 mirror HR surface :
1- large image span of the mirror surface (~center) before being cleaned :
one can see a lot of spots |
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removing of the M1 mirror, posted by Ronic Chiche at ThomX igloo about mechanics | lasers and optics | vacuum
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This afternoon, we installed a new M1 mirror, the only one for which the box was not already opened.
as the mirror should be "brand new", as the LMA has packaged it, we decided not to clean it with ultra-pure water and to install it
out of the box. |
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Amplifier laser diodes issue, posted by Ronic Chiche at Optical room about lasers and optics
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This is a long time issue for the ThomX amplifier : on the 4 pumping diodes available, the 1st diode has a higher temperature than the others around
40°C (see the picture).
the problem comes from the TEC which is not activated (see diodes parameter files in execel format). the related software windows are shaded. |
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ThomX ring injection kicker noise => USB communication issue with Alphanov amplifier, posted by Ronic Chiche at ThomX igloo about detectors and electronics
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several times already, when the electrons ring injection kicker is running @10Hz, we observed peaks at the same frequency on reflected and transmitted
photodiodes,
at the exact moment when the kicker is activated. we have in addition, USB communication issues with the Alphanov amplifier... the connection is |
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Onefive Origami 33MHz specs, posted by Loïc Amoudry at Optical room about lasers and optics 6x
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Power during ~20h, power after turn on, spectrum image and excel datas, polarisation and pulse length.
Powermeter measurments were done with a /10 filter.. 3 mW means 30 mW
Important: Onefive does not automatically locks after being turned on. |
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Onefive Origami 33MHz specs - Polarisation, posted by Ronic Chiche at Optical room about lasers and optics
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one rotate a lambda/2 before a PBS and meausure the refected power:
Pmax=35.6 mW
Pmin=107 µW |
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test des vérins ISP , posted by Ronic Chiche at Optical room about mechanics | cabling | software
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* les vérins de 20mm (axe Z) ont été testés sur table grace à une rallonge SUB-C - DB9, au chassis ISP et au soft
SUPERVISEUR écrit en labwindows CVI par Didier.
pour rappel, la course soft va de -1 650 000 à +1 650 000 pour 20mm de course, soit 0.6mm pour 100 000 de course soft. |
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test des vérins ISP , posted by Ronic Chiche at Optical room about mechanics | cabling | software
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Ronic
Chiche wrote:
* les vérins de 20mm (axe Z) ont été testés |
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test des vérins ISP 20mm et 6mm, posted by Ronic Chiche at Optical room about mechanics | cabling
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Après avoir utilisé la chaine : driver ISP - cable ISP DB9 - Feedthrough enceinte DB9-DB9 - cable perlé DB9-SUB-C - Capsule SUB-C,
l'ensemble de tous les vérins 6mm et 20mm ont été testés => ils fonctionnent TOUS.
Les vérins 6mm ont TOUS subis un HOME. cette commande cherche une fin de course du vérin et le place ensuite en position médianne. |
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test des vérins ISP 20mm et 6mm, posted by Ronic Chiche at Optical room about mechanics | cabling
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Ronic
Chiche wrote:
Après avoir utilisé la chaine : driver ISP - cable ISP |
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Détection de fuite, posted by Ronic Chiche at Optical room about vacuum
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Mail de Bruno Mercier du 18/10/2018 :
Un petit CR de la journée:
Nous avons effectué une détection de fuite sur l'ensemble des cavités optiques. Une fuite très importante a été |
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Remontage mécanique, posted by Ronic Chiche at Optical room about mechanics
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Mail de Yann du 12/10/2018 :
Je vous fais le bilan des actions effectuées :
1/ La mécanique a été remontée avec changement des billes céramiques, soufflet défectueux, ect... |
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Remontage des vérins, posted by Ronic Chiche at Optical room about mechanics
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Mail de Yann du 8/10/2018 :
Bonjour,
Tous les vérins sont maintenant OK ! Merci Ronic. |