New power record in ThomX cavity, posted by Ronic Chiche at ThomX igloo about lasers and optics 
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today, we were able to store more than 97kW in the FP cavity, always with the same parameter : 33% laser amplifier ratio
Ronic
Chiche wrote:
today, we were able to store more than 95kW in the FP cavity, always |
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New power record in ThomX cavity, posted by Ronic Chiche at ThomX igloo about lasers and optics
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yesterday, we were able to store more than 98kW in the FP cavity, always with the same parameter : 33% laser amplifier ratio
Ronic
Chiche wrote:
today, we were able to store more than 97kW in |
New password for login on the ThomX computer, posted by Ronic Chiche at ThomX igloo about software
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the previous password has expired.
the new access from the computer :
login : .\$jehanno |
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New multiplication factor for the Fabry-Perot intra-cavity power, posted by Ronic Chiche at ThomX igloo about lasers and optics
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last week, we measured the transmission of a plan mirror from the same batch than the ThomX mirrors and we got ~ 1.75ppm instead of 3ppm which was the
calculated value by the LMA.
previously, we put 1/3ppm = 333 333 as multiplication factor. |
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New mirrors batch informations, posted by Ronic Chiche at ThomX igloo about lasers and optics
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| the 2 files describe the specfications for the16 mirrors ordered (4 for ThomX + spare, 4 for SBOX + spare) and the measurements made by the LMA. |
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New locking scheme, posted by Ronic Chiche at Optical room about detectors and electronics
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Before, the locking scheme was to produce an error signal with the PDH box, send its output to the electronic amplifier box and then to the laser EOM
for the fast loop and to the Laselock input. The drawback was changing one loop gain, changes also the other loop gain.
Now, the locking scheme is the error signal coming from the PDH box is directly sent to the Laselock input and in a same time to the electronic |
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New direction for cavity motors, posted by Ronic Chiche at ThomX igloo about mechanics | software
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from now on, one reverts the FP cavity motors direction to compensate the long drift from the begining of the project.
the motor MOT.06 will be used for the upward direction (presently -1 082 650 steps)
and the motor MOT.03 will be used for the downward direction (presently +37 170 steps) |
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New design for PDH boxes, posted by Ronic Chiche at Optical room about detectors and electronics
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A new design has been studied for the 5 PDH boxes to better match the low (33MHz) repetition rate of the ThomX laser.
the 5 PDH boxes have been modified and tested (see the attached report).
A mixer has been integrated to the PDH box for a more simple use. |
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New Suprasil mirror from LMA, posted by Loïc Amoudry at Optical room about lasers and optics
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14/05/19:
New Suprasil mirror received. It will replace the S-BOX suprasil mirror on ThomX which was already replacing the sapphire mirror.
First finesse measurement: 14000 |
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New Suprasil mirror from LMA, posted by Loïc Amoudry at Optical room about lasers and optics
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19/09/2019 : email from Chrisophe Michel about AR coating of LMA mirrors after reading that Ta2O5 layers can be damaged in vacuum if not protected by
a SiO2 layer :
"oui tous nos coating standards HR se terminent par une couche de protection SiO2 Lambda/2. |
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New Mirrors from LMA _ Images, posted by Manar Amer at Optical room about lasers and optics
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Today we tested a mirror from one patch
image is for the front face of the mirror
PowerPoint has more details about the images |
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Motors connexions, posted by Loïc Amoudry at Optical room about mechanics
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Motors are connected. The true mirror's name are P1 for injection mirrors, S2, S3 and P4. (S=spherical, P=planar).
They are still some old schemes (and notations on the cavity) which mention M1, M2, M3 and M4. I make the link here:
M3 = P1 |
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Motors Z axis reversed, posted by Loïc Amoudry at Optical room about mechanics
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S2 and S3 z-axis are initially at 1/4 (5mm/20mm) of there range over ~20mm range. This is meant to be able to spread them up to ~15mm in case of
thermal effect.
Actually, they are in an opposite position. Means that they can only be spread of 5mm from the initial position. |
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Motors Z axis reversed, posted by Loïc Amoudry at Optical room about mechanics
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All Z motors (for P1, S2, S3 and P4) have been initialized again with a proper HOME command with their own controller with the "superviser"
software (which means they all moved to the +1650000 position).
Thus, they have been moved to their default position : +825000 for spherical mirrors (S2 and S3) and -825000 for plan mirrors (P1 and P4). |
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Motor issue, posted by Ronic Chiche at Optical room about mechanics | detectors and electronics
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Today, Axis 9 (Z-axis of P1) has blocked the software which drives all the motors.
impossible to bypass the problem.
I had to : |
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Motor issue, posted by Ronic Chiche at Optical room about mechanics | detectors and electronics
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Today again, same problem with axis 9 blocking the controlling software during the mirror alignment procedure.
after opening the motor 9-16 controlling crate, we saw 2 screws (RX- and TX+ of the controller) which were badly screwed.
we firmly screwed them... could it be the cause ? |
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Mirrors sent to LMA, posted by Loïc Amoudry at Other about lasers and optics
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30/01/19 - As LMA people came, we discussed about the spots on ThomX mirrors which should be clean. As mentionned in "SBOX commissioning",
these spots are normal.
An other question appeared during the conversation about the storage time and location of these mirrors. They have been stored for more than |
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Mirrors sent to LMA, posted by Loïc Amoudry at Optical room about lasers and optics
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| Mirrors have been sent today to LMA for cleaning and maybe annealing (recuit). 3 ULE of ThomX and the fused silicate for injection (trans @140ppm ). |
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Mirrors checked with binocular microscope, posted by Loïc Amoudry at Optical room about lasers and optics
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29/01/19 - ThomX mirrors have also been checked with binocular microscope. They shown the same spots as S-BOX mirrors.
1st image shows reflective face of a spherical mirror.
2nd image shows reflective face of M1 (sapphire). |
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Mirror's cleaning and finesse, posted by Loïc Amoudry at Optical room about lasers and optics
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Summary of what have been cleaned the last week:
P1 with isopropanol, finesse 11000
P4 with isopropanol, finesse 13000 |