During the weekend 23-24th of October, the lab and ThomX suffered a power breakdown.
All the pumping systems had to restart.

as a consequence, the pressure on Monday 25th morning was 4.3e-9 and 4.6e-9 mbar in the left and right vessels.

this morning, the Tuesday 26th, the pressure is 1.4e-9 and 3e-9 mbar.
now, these pressures are compatible with the opening of the valves!

A plot showing the descend of the vacuum in the mirror chambers (data to plot it obtained yesterday evening)

The regions where there is a drastic decrease is when the ionic pump was turned on.

Today in the morning the pressure was

• on the left                    :  1.3*10^-9 mbar
• on the right (sortie X)  :  4.9*10^-9 mbar

in the evening the pressure was

• on the left                    :  1.4*10^-9 mbar
• on the right (sortie X)  :  4.7*10^-9 mbar

Leakage test done in the afternoon.

The method :

• an atomic mass spectrometer is connected to the mirror chamber and a measurement is taken to see all the atoms and molecules in the chamber
• after a Helium gas is spread around the outside of the chamber
• there is a leak if there is a spike at Helium (4 amu)

Attached is a picture of the spectrometer plot.

Conclusion: No leak in the cavity and the pressure is expected to decrease in the coming days

The pressure now is:

• on the left                    :  1.6*10^-9 mbar
• on the right (sortie X)  :  1.4*10^-8 mbar

**Note: there is an increase in the pressure after doing the measurement, which is expected from the spectrometer bumping ions to do the measurement.

At 9h30 in the morning, the pressure on the mirror chambers is:

• on the left                    :  1.6*10^-9 mbar
• on the right (sortie X)  :  6.5*10^-9 mbar

it appears to have decreased significantly compared to the previous deccend !!!!!!

At 10h in the morning, the pressure on the mirror chambers is:

• on the left                    :  1.9*10^-9 mbar
• on the right (sortie X)  :  1.0*10^-8 mbar

Bruno mentions that the pressure on the left is descending too slow,  a leakage check to be done on Tomorrow by the vacuum branch.

At 15h30 in the afternoon, the pressure on the mirror chambers is:

• on the left                    :  2.0*10^-9 mbar
• on the right (sortie X)  :  1.4*10^-8 mbar

the pressure decreased by 0.2 in ~ 5 hours for right , but increased by 0.1 for left

not an accurate reading for the change over time

will need to get the pressure vs time graph from the control room. 

Reminding: the opening of the valves is the responsibility of the vacuum group only.

At 10h45 in the morning, the pressure on the mirror chambers is:

• on the left                  :  1.9*10^-9 mbar
• on the right (sortie X)  :  1.6*10^-8 mbar

The pressure for the mirror vacuum chambers needs to be ~ few 10^-9 mbar for the valves to be open to the electron ring (the rest of the vacuumed ThomX)

• When connecting the Ethernet cable from the hub to the computer, it must be connected to the correct one (shown in green arrow in photo), it is not the usual internet
• the Motor controllers are under the Cavity table.
• The last image shows the positions of each mirror (To be checked if they are actual readings)

Now, both vessels are pumped by an ionic pump (both Turbo pumping entrances have been closed).
the primary pump has been removed from the left vessel.
we kept the primary pumping on the right part "in case of".

Now, the pressure on the right vessel is 2.1e-8 mbar.
the pressure on the left vessel is stable around 1.9e-9 mbar.

after the WE, the right vessel vacuum level is 1.7e-7 mbar (primary + turbo pumps)

and the left vessel vacuum level is 1.8e-9 mbar (primary + turbo + ionic pumps)

I will ask Frederic to start the right vessel ionic pump.

This afternoon with Manar, we finished connecting FP-cavity mirrors motors and alignment mirrors motors to their 3 ISP controllers.
We also added an Ethernet hub on top of these controllers to merge the controller's connections to the computer.
We added some cable extensions to the alignment mirrors motors.

We tested the connection and the controlling software made by Didier.
We used the supervisor software as one needs the trick to bypass the Didier safety procedure embedded in its user's software (Chassis12.exe and Chassis3.exe)
We were able to move the motors (tested only upon the 4 motors of the alignment mirrors) but sometimes it seems we have some connection bugs which freeze the access to the ISP controllers.

After some hours of pumping, the vacuum level decreased properly on the left vessel (input mirror) but it seems to decrease slowly on the right vessel (end mirrors).
In consequence, Frederic has been able to start the ionic pumping only on the left vessel (+ Turbo). The right vessel is still pumped by the Turbo pump.
at 5 pm, the pressure was 1.4e-8 mbar for the left vessel and 1.9e-6 mbar for the right vessel.
Depending on the pressure on Monday, Frederic could start the ionic pumping for the right vessel too.

the ionic pumps have been also connected this morning but not powered on, yet.
the vacuum group is waiting for a vacuum level below 10**-6 to power them on.

it should be the case this afternoon.

about permanent cables on the optical table for the vacuum system, there are 2 for the gauges and 1 for the ionic pump for each vessel, then 6 in total.

• The electron ring has been vacuum inside it, but the valves connecting it to the two mirror chambers are closed. Before commencing to do measurements on the cavity, we must place the mirrors under the proper vacuum and open the valves connecting them to the electron ring.

• The vacuum system is consistent of three levels; Normal (max ~10^-3 mbar), turbo (max ~ 10^-7 mbar) and ionization.
• With the help of  Frédéric LETELLIER and Mercier Bruno from the vacuum department in the morning.
  • Installation of the first level vacuum (normal pump)
  • Installation of the second level vacuum (turbo pump)
    • can reach up to 1350 Hz = 81 000 rotation per min (how fast it reaches max rotation depends on how good the first level pump was done)
  • Installation of the connections to the gauge meter, there are two gauges, one for first level and one for second.
• All turned on !!

• Both are on and can be monitored from ThomX control room
  • The attached photo from the control room shows how we will be able to get a graph of vacuum over time.
    • (we were able to reach approximately for Volume 11 and Volume 12 respectively 4.1*10^-6 and ~8*10^-7)
      • to explain Volume 11 and volume 12 (look at Location of ThomX vacuum valves photo)

• A photo of the control module placed outside the bunker to control the optical cavity vacuum is attached
• This afternoon the third system will be installed and turned on

*** Note after vacuum is set there will be three permeant cables inside the cavity box for monitoring.

This afternoon, we continued to clean the housing with Manar and Daniele.
we did a dust measurement after cleaning with the two ceil doors opened and the dust meter in the middle of the table, and it counted ZERO!
it doesn't mean the housing is perfectly clean but it is clean enough to pay attention now to cleanness.

Then from today, we have to wear overshoes at the entrance of the ThomX casemate and wear clean coats below the airflow (we installed the coats inside the FP-cavity airlock).

for cabling motor controllers, we discussed with Aurélien about the Alphanov amplifier position on the optical table.
we don't have the last schemes... so, Aurélien sent an email to Guillaume Machinet and Yann to get them.
normally we could let the computer inside the casemate close to the optical table while the electron beam is not filled inside the ring.
as it is dumped on the opposite side of the casemate, the computer position should be radiation safe for now.

One half-height rack, close to the optical table, has few network devices BUT takes almost all the rack place!
we could easily fit the hexapod controller in this rack with "logical" cabling.

This morning with Manar, we started to clean the floor around the cavity, the outside part of the panels of the housing, and the optical table.
we will continue this afternoon and, in the end, we will make some dust measurements.
do we know who in ThomX is in charge of the cleanness of the casemate (bringing overshoes, sticky floor, cleaning company for the floor,...)?

the motors controller mini-rack has been installed under the optical table.
but it is still not connected to motors or computer.

we saw a chiller beside the optical table... is it the laser amplifier chiller ?

there is also the hexapod controller which is presently close to the wall.
do you remember where is the final place of this controller?

the two vessels of the FP-cavity are presently at room pressure with nitrogen inside.
it has to be put under vacuum (~ 10**-8) before opening the 2 valves which are separating the vessels from the electron ring.
we can't make any Finesse measurement until the vacuum is made and the valves are open.
we discussed with Bruno about that, and he is aware of the situation. He said he will try to pump the vessels as soon as possible
in order to be able to inject a laser on the next opening, next week.

The AC plug and the power cord of the airflow were quite hot because they have been dimensioned for 16A current and the total current is above.
AirC2 company should replace them with 32A equipment (6mm2 power cord + 32A Hypra AC plug) in the next days.
 

On the 27th of May, the Airflow has been dismounted from the optical room to be mounted around the optical cavity by the AirC2 company.

here is email from Yann :

Le flux est rentré dans la casemate.
Lundi la société AirC2 revient pour installer les rideaux.
Petits couacs :
- 2 plaques de faux plancher à découper
- le saut de loup à été déplacé (à voir si c'est OK pour tout le monde)
- filet de toit à retendre
- poutres du toit à remettre
- main courante du faux plancher à retirer
- attention au coin du flux au niveau du saut de loup (à baliser et protéger)

On the 19th of May, the optical table has been moved inside the ThomX concrete housing and connected to the Symetrie hexapod and to the electron ring.

Symetrie guys started to test the hexapod and they put some software limits around the predefined zero position.