Vide / Vacuum

• The beam line is built up of elementary module. A module includes vacuum equipment between two valves or beryllium windows. Into a module there is at least 1 pirani gauge, 1 penning gauge, 1 ion pump, 1 remote or manual valve.
• Pirani and penning gauges interlock the ion pump, and the penning gauge interlocks the remote valve. Thresholds are 5E-3 mbar for pirani and 1E-6 for pennings.
• The interlock system is based on PLC (TSX17) and aims to prevent material damage in case of leaks or accidental venting. There is one PLC plus 2 extensions for remote valves and ion pump interlock, and a PLC for the safety shutter. When all is ok on vacuum the PLC gives an authorization to PSS to open beam line's front end. Furthermore as the beam line is a dual branch line, another PLC plus an extension is used to control absorbers placed on each branch on the first common vessel (E1) of the beam lines. These absorbers enable to stop the beam on a branch without stopping the second one. The front end is interlocked on error conditions appearing on E1 vessel.
• On the 2 optic hutches there are also interlocks on temperature or flux on cooling system. This represents 4 signals feed into the interlock system :
• All temperature on OH1 (SU1,SD1,HS1,SU2,SD2,SB2,SF2,HS2) input I0,7 on PLC
• Mirror M1 OK chiller and temperature input I0.13 on PLC
• All temperature on OH2 (SU3,SD3,SB3,SF3,Mono,HS3) input I0,20 on PLC
• Chiller OK input I1,6 on PLC

Optic hutch 1 shared with FIP BM30A

In this hutch there are 3 vacuum sections :

• section 1 [RV1:RV2] is mainly a pipe plus a pumping cross
• section 1 [RV2:RV3] contains the E2 vessel plus a manual valve to isolate E2 if FIP needs to open its mirror
• section 1 [RV3:RV4] includes the first mirror plus the beam shutter 1
  

Optic hutch 2

In this hutch there are 4 vacuum sections :

• section 4 [RV4:RV5] for slits 3
• section 5 [RV5:RV8] for monochromator

  The monochromator will probably have its own PLC to control the valves RV6 and RV7 and interlocks on LN2 cooling.

• section 6 [RV8:RV9] for slits 4
• section 7 [RV9:RV10] for second mirror

The last section is simply a pipe with a beryllium window.

To have more detail on the rack controlling pumps and vacuum gauges go on rack description page.