F. BORGNOLUTTIOct. 16th 2012
Winding Test plan for the MQXF Cable
F. Borgnolutti 2
Outline
•Mechanical stability of Rutherford Cable
• Winding Test Plan
16/10/2012
F. Borgnolutti 3
Mechanical stability of Rutherford Cable
16/10/2012
• The mechanical stability of a cable reveals itself during a coil winding through what is called popped strand.
•In a coil popped strands can cause insulation damages and high stress points due to oversizing of the cable:
Ex: HQ coil 18, lot of popped strands in Layer 2 produces inter-turns shorts
• Some parameters that has an impact on a cable mechanical stability: Strand diameter: a smaller diameter makes a cable more flexible Compaction factor Cable aspect ratio Pitch length Pole thickness ……
HQ cable, unfavorable winding direction
F. Borgnolutti 4
Mechanical stability of Rutherford Cable
HQ01d/e
16/10/2012
Inner layer (favorable winding direction): All the quench occurred in the straight section
Outer layer (unfavorable winding direction): All the quench occurred in the heads: popped strand effect?
F. Borgnolutti 5
Winding Test Plan
• Winding test performed around a pole piece obtained from a scale up of the HQ IL pole (should give us an idea about the mechanical stability of a cable):
Both favorable and unfavorable winding directions will be tested
•The pole piece will be ready in about one week (3D printing) (First cable expected by the end of October)
• In the mean-time a pole piece that is based on a real MQXF cross-section is being designed at Fermilab.
16/10/2012