Login

MBHDP301 test - assembly - FEA - mechanical measurements

→ Europe/Zurich
CERN

CERN
Zoom link
Hide

Dear all, 

 

Thank you for the presentations and for the discussion. The minutes of the meeting are listed below, and they will be also in the indico event: https://indico.cern.ch/event/1309024/

 

Main outcomes form the presentations:

Update on the powering results of MBHDP301

  • Aperture SP302 all the training quenches are happening in two main locations in coil 213: i1-ii (location 1) and close to i1 (location 2). Ramp rate studies shows that the highest local damage is likely in location 2.
  • Aperture SP301 could not be tested. During the first quench heater discharge without current in the magnet, a quench heater failed and damaged the quench heater to coil insulatio that is going to be validate when we open the magnet.

Analysis of assembly data of MBHDP301

  • The second one has been collared with less excess than the first one due to the high stresses at maximum collaring force (200 MPa in a collar with a target of 170 MPa).
  • Further information:
    • Include the values of the de-collaring of coils 212 and 213.
    • Relate the shimming and pre-stress with the voltage taps position and quench location.
    • Check a possible asymmetry in the assembly of SP302 (with fuji paper and shimming plan).

3D mechanical behaviour of the 11T cold mass at cryogenic temperature

  • The two mitigation solutions are presented.
  • Further information:
    • Details in the 3D model: change shape of the instrumented collars (not the nominal one), only compare the values of the simulations with the connection side. 
    • Focus on the end cage activation and powering stresses on the coil inner layer.

Update on the mechanical measurements of MBHDP301

  • Collars stress release at cold and powering.
  • Bullet gauges and end cage rods compression is unbalanced at cold. Both have different longitudinal stiffness in connection side and non-connection side at powering. 
  • Further analysis (SMT and MME-EDM)

 

Next steps: 

  • Further investigation about the state of the coils and mechanical measurements in the quench location. Teams involved: SMT and MME-EDM. 
  • Disassembly the magnet. Teams involved: SMT, LMF and MME-EDM. 
  • De-collar the aperture SP301 (coils 214 and 108). Teams involve: SMT and MME-EDM.
  • Check if the coil 214 (with the quench heater problem) can be recovered or not. If not, we have the coil 106. Teams involve: SMT.
  • Propose a strategy and plan that will be discussed in September. Teams involve: SMT.

 

If you want to comment on any of the points, do not hesitate to call me or write me an email.

 

Kindest regards,

Carmen

There are minutes attached to this event. Show them.