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Entry   Pressure On mirror Chambers, posted by Manar Amer at ThomX igloo about vacuum 19102021_vacuum_pressure_on_mirrorsChambers.jpg
    Reply   Pressure On mirror Chambers, posted by Manar Amer at ThomX igloo about vacuum 19102021_vacuum_pressure_on_mirrorsChambers_15h30.jpg
       Reply   Pressure On mirror Chambers, posted by Manar Amer at ThomX igloo about vacuum 20102021_vacuum_pressure_on_mirrorsChambers_10h10.jpg
          Reply   Pressure On mirror Chambers, posted by Manar Amer at ThomX igloo about vacuum 21102021_vacuum_pressure_on_mirrorsChambers_9h30.jpg
             Reply   Pressure On mirror Chambers Leckage Test, posted by Manar Amer at ThomX igloo about vacuum 21102021_vacuum_pressure_on_mirrorsChambers_16h30.jpg21102121_MassSpectrometerOpticalCav.png
Message ID: 30     Entry time: Thu Oct 21 18:31:11 2021     In reply to: 29
 Author: Manar Amer 
 Status: Fixed 
 Type: info 
 Category: vacuum 
 Location: ThomX igloo 
 Title: Pressure On mirror Chambers Leckage Test 

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.

 

Manar Amer wrote:

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 !!!!!!

Manar Amer wrote:

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.

Manar Amer wrote:

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. 

 

Manar Amer wrote:

 

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

 

 

 

 

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