09.30 CARME chamber status
Edwards scroll pump ON
Edwards Speedivac valves #1 & #2 OPEN
VAT gate valves OPEN
Re-connect Leybold Pirani gauge to local display/control
CARME chamber pressure 2.4mbar
Scroll pump should be able to achieve < 0.1mbar - indicates significant leak
Davide will first check bolt torques for all flanges opened during most recent vacuum cycle
12.05 Additional torque did not resolve problems
ML test COF600 seal with isopropanol and observed increased chamber pressure
Will open COF600 seal after lunch
13.55 COF600 seal removed - one section marked by Kapton tape shows some distortion and a burr on the inner diameter - see attachments 1 & 2.
ML speculated that perhaps the seal was lightly too long and a section of circumference was forced outwards?
Vacuum surfaces cleaned with isopropanol and tissues - red/brown discoloration probably indicating copper observed
14.30 New COF600 seal installed, flanges closed, bolts finger tight, bolts then systematically torqued in small increments
COF600 torques finger tight, 10, 20, 30, 40, 60, 80, 100, 120, 140, 160Nm x2
DN100 flanges doenstream finger tight, 8, 16, 24Nm
16.40 Start scroll pump and slowly rough chamber
18.00 Roughing CARME chamber pressure flatlines c. 30mbar indicating a large leak.
ML ran some isopropanol around COF600 flange and observed response in roughing pressure of c. 0.2-0.3mbar at c. 30mbar which appears to confirm COF600 is leaking.
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