Besprechung S3HC Druckprobleme

Friday 6 Nov 2026, 11:00 → 12:00 Europe/Zurich

SZ-WWHB/106 (PSI)

Alessandro Citterio (PSI - Paul Scherrer Institut)

Cryo_instabilities_06-11-2026.pdf

Cryo_instabilities_06-11-2026.pptx

schematic with non-return valves.pdf

Goal of the meeting: analysis of the oscillations of the cryo-parameters experienced since September 2026, and possible remedies. 

Conclusions:

• We believe that the physical process behind these oscillations has been correctly described in the elog https://elog-gfa.psi.ch/Cryogenics/794 . Then the installation in the next winter Shutdown 2026 of two non-return valves, one in the line “S” (warm return) and one in the line  “T”, and one safety valve in the line “S” – see schematic - is confirmed.

 

• Modelling a cryo-plant in exact way to obtain output data precise enough to predict its cryogenics behavior would require an extensive program of study over more years, as a PHD and/or postdoc program, and tight supervision from cryogenics and controls experts at the same time. Because of the high complexity of the cryogenics system, at the moment a simulated model of the whole cryo-plant is not considered as the preferred approach to solve problems such as the thermal/pressure oscillations we experienced in September-November 2026.