14T+ Magnet Design

Tuesday 23 Jan 2024, 10:45 → 11:45 Europe/Zurich

10:45 → 11:15 Present status of 14T+ magnet design

Speaker: Gloria Bellini (Ministere des affaires etrangeres et europeennes (FR))

Presentation 23.01.24.pdf

Presentation 23.01.24.pptx

23/01/2024: Follow-up meeting

 

Participants: Juan Carlos, Susana, Gloria and Jose

Agenda:

-          Gloria to present the status on his work for the 14 T design. Presentation divided in two main parts: 40 mm aperture and 50 mm aperture designs.

-          Juan Carlos to give an update on other on-going activities and general discussion:

o   Cable received from Ian (MQXF with large width)

o   Nico to present update on winding tests next week

GLORIA’S UPDATE:

Magnetic optimization with 2 main objectives:

• +/- 10 units in all harmonics
• Minimize the ratio between peak conductor field and aperture field

For the mechanical optimization, Gloria will add a slide with the main figures of merit.

DESIGN 1 - 40 mm aperture:

§  DESIGN A: Gloria played with the shape of the vertical pad for getting a general understanding of the impact on geometrical field errors. We should keep in mind that persistent currents (magnetization) will pollute the Field Quality (FQ) at low current, so marginal gains at low field are not of interest. In other words, for complex pad geometries improving FQ at injection, the gain is marginal and the complexity in machining is not worth it.

§  DESIGN B: Then, Gloria decided to investigate a vertical pad made with an slight angle at the vertical symmetry plane (similar to LHC main dipoles). In addition the height of the pad was reduced:

o   However, the vertical pad cannot be reduced because we need the space for the flare ends (In first order, we can keep Susana’s reference pad height, since she took a look to this based on FRESCA. Slides are on INDICO). More recent designs like TFD are able to accommodate a smaller pad, we will check this later on.

o   In the same lines, doing a parametric study on different pad alternatives, Gloria found that the impact on peak field is not big. This is more or less expected because the changes are not drastic. We all agreed that the priority should be FQ rather than improving peak field the ratio (although we need to keep it more or less acceptable), the main objective is to target an accelerator quality magnet.

o   In the mechanical analysis, the position of the keys seems not optimal. Susana suggest to check the deformed shape of the structure for understanding the bending. 

DESIGN 2 - 50 mm aperture:

§  Gloria started playing with different cable designs. Cu/SC ratio for 1.1 mm cable needs to be changed to 0.9.

§  We set the next goals for the analysis: Gloria should take the 1.1 mm cable and go for a reasonable Cross Section (CS). Then she will try to have the same coil area with the other strands and compare designs (load lines).

§  On the slides she presented today, note that the turns on the outer layer that go beyond the IL are not efficient at all. We suggest to plot in ROXIE the contribution of each turn to main field.

ACTION ITEMS:

§  40 mm: Finish playing with the mechanical analysis (key position, pad sizes and bladder positions)

§  50 mm: Cu/SC ratio for 1.1 mm cable to be changed to 0.9. Take 1.1 mm and go for a reasonable CS, then you try to have the same coil area with the other strands and you compare designs (load lines).

11:15 → 11:45 General discussion on next steps

Speaker: All