ELOG CARME

AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40

CARME

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Entry time:	Fri Apr 4 17:15:54 2025
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> > 09.20 CARME chamber at atmospheric pressure as expected. > > Will open CARME chamber and inspect COF600 wire seal for similar (or other) issues to the seal removed yesterday. One possibility is that the COF600 flange > surfaces/structures are misaligned and part of seal is 'escaping' the seal zone. Given the flanges close easily the misalignment would have to be small. > > 13.30 Observations > > The bolts on the upstream feet of the far detector chamber are all loose and have probably been so for some time > > Based on measurements with calipers and the insertion of shims into the radial gap between COF600 flange surfaces the COF600 flanges may be misaligned and rotated > transversely by a fraction of a millimeter. The challenge is that the chamber is not designed for fine transverse adjustments and it is not easy to measure the changes. > > The Pfeiffer recommended procedure for closing COF seals is to start tightening bolts diametrically and then to tighten sequentially > > https://www.pfeiffer-vacuum.com/en/know-how/mechanical-components-in-vacuum/connections/detachable-flange-connections/cof-flanges/ > > The plan > > Adjust position of far detector chamber and secure upstream feet bolts > > Close COF600 flange using Pfeiffer recommended procedure > > Today is Friday so it will probably be Monday before we can pump the CARME chamber > > 13.50 Another view > > Grosmontage also inspected the COF600 seal this afternoon. They said that it was important that the seal should be installed under tension to ensure that it remained > in position as the flanges were closed and the bolts begin to be tightened. They think the seals are a little too large in circumference but that they can shorten one on > Monday morning. Encoding: HTML ELCode plain Suppress Email notification

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