AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40
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Message ID: 421     Entry time: Tue Jul 18 08:16:28 2023
Author: TD 
Subject: Pumping down. Issues found with one detector. 
09.15 Following overnight pumping of CARME chamber by Leybold turbo
      Pirani 1.00e-3 mbar IE514 2.83e-7 mbar

     The Leybold IE514 gauge currently in use is the CARME unit ( serial # 1054 ). The calibration data can be found at https://elog.ph.ed.ac.uk/CARME/56


09.44 Pirani 1.00e-3 mbar IE514 2.71e-7 mbar

10.10 Leak tester attached to backing line

      Valves to leak tester and turbo (connection to Edwards scroll pump in between) closed.

      Stop Edwards scroll pump with magnetic valve 'red' button - magnetic valves closes and Edwards scroll pump is switched off.

      Open valves to leak tester and then (slowly) turbo.

      Wait for leak tester to settle in e-12 mbar.l/s range. Leak tester pressure 3.6e-3 mbar. IE514 2.69e-7 mbar.

11.00 Pirani 1.00e-3 mbar IE514 2.42e-7 mbar
      Leak tester 1.8e-10 mbar.l/s

13.04 Pirani 1.00e-3 mbar IE514 2.06e-7 mbar

      Leak testing.
      Downstream DN100 flanges from CARME to dipole OK
      Lower NEG power connector feedhtrough (downstream chamber) OK
      Left hand side (looking downstream) bellows OK

      c. few e-9 mbar.l/s leak bottom left (lookimg downstream) of COF600 wire seal

      Additional torque to M16 bolts bottom left - c. 10 bolts -> 220Nm+

      c. 0.1-0.3e-11 mbar.l/s

      Further checks around circumference of COF600 seal reveal some small leaks c. e-11-12 mbar.l/s.? However background rate
      in leak tester too high for sensitive test - will await recovery to resume checking.

14.00 Pirani 9.8e-4 mbar IE514 1.96e-7 mbar
      Leak tester 4.9e-10 mbar.l/s


14.35 DSSSD test
      IE514 OFF

Ambient temperature 21.5 deg C

Top right
-10V -4uA
-20V 10uA
c. -30V > -20uA trip

Top left
-150V -5.15uA

Bottom left
-150V -4.97uA

Bottom right
-150V -6.33uA

Top right (repeat)
-20V -10uA
-25V -14uA

15.28 IE514 ON
      Pirani 9.8e-4 mbar IE514 1.87e-7 mbar

15.40 c. few e-9 mbar.l/s leak around magnetic valve - probably not an issue in terms of backing performance but may interfere with/confuse leak testing

16.05 Pirani 9.8e-4 mbar IE514 1.74e-7 mbar
      Leak tester 1.2e-9 mbar.l/s

Will leave CARME pumping with leak tester on roughing line and see whether leak rate recovers. If so, will continue leak tests tomorrow. 

18.50 Pirani 1.00e-3 mbar IE514 1.48e-7 mbar
      Leak tester < 1e-12 mbar.l/s (leak tester valved off)
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