Thermal and Magnetic Shield

Wednesday 28 Oct 2015, 10:00 → 11:00 Europe/Zurich

376/1-020 (CERN)

Quick summary of today’s meeting.

Magnetic Shield:

• The preferred shape is a rectangular parallelepiped (i.e. a box). An offset of the vacuum vessel internal surface would have too many features.
• The shield will be in mainly 4 pieces (3 for the bottom + 1 cap on top)
• Any contact with the vacuum vessel is to be avoided for vacuum reasons (reported by Nik, reason to be clarified)
• The tolerances on the vessel may be an issue, however industrial experts say the 3 mm thick mu metal shield can have a +- 2 mm tolerance
• Nik is exploring different joints in order to minimize flux leakage. The position of the joints – however- should be as far as possible from the sensible volumes (i.e. cavities)

Thermal Shield

• Concept: Al6061 frame + Al1060 (or 1050?) for plates
• The interface with the jumper is to be designed as well. One possibility is that the shield has a pipe that goes into the jumper
• The 2 K feed line is too close to the shield, that therefore needs to be slightly higher (30 mm min distance)
• The idea of cooling only on top will be carried on. Major obstacle is the contact conductance, whose effect may change the overall performance. I attach here a paper that provides a formula for estimating the conductance (pag. 65) – thanks Fede! - .

Here at CERN we remain available for any support (design, modelling and analysis). Don’t hesitate to contact us.

Also, we’ll meet again next week. There’s a problem with the videoconference room availability, but I’ll let you know.

10:00 → 11:00 Discussion

Conveners: Carlo Zanoni (CERN), Federico Carra (CERN), Luca Dassa (CERN), Niklas Templeton (STFC), Norbert Kuder (CERN), Ofelia Capatina (CERN), Rama Calaga (CERN), Teddy Capelli (CERN), Thomas Jones (STFC)