1 / 19

Insertion Magnets and Beam Heat Loads

Insertion Magnets and Beam Heat Loads. Beam heat loads Magnet design issues related to heat loads. Ranko Ostojic AT/MEL. LHC experimental insertions. pp collisions at 7 TeV generate 900 W at L nom carried by the secondaries to each side of LHC experimental insertion. P/L (W/m).

kato-gardner
Télécharger la présentation

Insertion Magnets and Beam Heat Loads

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Insertion Magnets and Beam Heat Loads • Beam heat loads • Magnet design issues related to heat loads Ranko Ostojic AT/MEL

  2. LHC experimental insertions pp collisions at 7 TeV generate 900 W at Lnom carried by the secondaries to each side of LHC experimental insertion. P/L (W/m) Final focus Matching section Separation dipoles Dispersion suppressor

  3. Heat load in the Low-b Triplet External Heat Exchanger Average load: 7 W/m Peak: 14 W/m Total: 205 W T. Peterson, FNAL Technical Note July 2002

  4. Heat load in the Low-b Triplet Peak power density: 0.45 mW/g N. Mokhov et al, LHC Project Report 633

  5. MQXA low-b quadrupole (KEK) Coil ID 70 mm G = 215 T/m at 1.9 K Conductors 1/2 Width 11/11 mm Mid-thick 1.48/1.34 mm Strand dia 0.815/0.735 mm No strands 27/30

  6. MQXA Heat Transfer Experiments (I) Exp Conductor Strand material Cu-Ni Strand dia 0.814 mm No strands 27 Cross-section 1.47 x 11 mm Length 177 mm Insulation Upilex 15 mm/25 mm pitch 50% overlap + Upilex 6 mm/50 mm B-stage epoxy 10 mm pitch 8 mm (2 mm gap) N. Kimura et al, IEEE Trans. Appl. Superconductivity, Vol 9, No 2, (1999) p 1097.

  7. MQXA Heat Transfer Experiments (II)

  8. MQXA Heat Transfer Experiments (III) • Conclusions: • effective channel diameter ~ 35 mm • Conduction important at higher heat flux • AC loss measurements give consistent results • Maximum allowed heat load ~ 18 mW/cm3

  9. MQXB low-b quadrupole (FNAL) Coil ID 70 mm G = 215 T/m at 1.9 K Conductors 1/2 Width 15.4/15.4 mm Mid-thick 1.45/1.14 mm Strand dia 0.808/0.650 mm No strands 37/46

  10. MQXB Heat Transfer Experiments (I) Insulation 1st coil layer Polyimide 9.5 mm/25 mm pitch 55% overlap + Polyimide 9.5 mm/50 mm QXI pitch 11.5 (2 mm gap) 2nd coil layer Polyimide 9.5 mm/25 mm pitch 43% overlap Polyimide 9.5 mm/25 mm QXI pitch 50% overlap L. Chiesa et al, IEEE Trans. Appl. Superconductivity, Vol 11, No 1, (2001) p 1625.

  11. MQXB Heat Transfer Experiments (II) • Conclusions: • AC loss results consistent with assumption of “blocked • cooling channels” • Maximum allowed heat load ~ 1.6 mW/g

  12. MQM matching quadrupole Coil ID 56 mm Gradient 200 T/m at 1.9 K 160 T/m at 4.5 K Conductor Width 8.8 mm Strand dia 0.480 mm No strands 36 Insulation Polyimide 8 mm/25 mm pitch 50% overlap + Polyimide 9 mm/50 mm unc. poly. 6 mm pitch 11 mm (2 mm gap)

  13. MQY wide aperture quadrupole Coil ID 70 mm Gradient 160 T/m at 4.5 K Conductor 1/2 Width 8.3 mm Strand dia 0.48/0.73 mm No strands 34/22 Insulation Polyimide 8 mm/25 mm pitch 50% overlap + Polyimide 9 mm/50 mm unc. poly. 7 mm pitch 11 mm (2 mm gap)

  14. Separation dipoles (BNL) Coil ID 80 mm Field 3.8 T at 4.5 K (2.4 T at 4.5 K in IR1/5) Conductor Width 9.73 mm Strand dia 0.648 mm No strands 30 Insulation Kapton CI 9 mm wide 50 mm thick pitch 50% overlap + Kapton CI 9 mm 50 mm pitch 50% overlap

  15. MQTL Coil ID 56 mm Gradient 120 T/m at 1.9 K 90 T/m at 4.5 K SC wire 0.73 mm x 1.25 mm (with enamel insulation) Coil Insulation epoxy impregnated

  16. Heat transfer in Saturated He Bath Quench Stability Study of J-PARC Magnets Cable and insulation identical to MQXA 20 mJ/cm3 in a 10 ms pulse Y. Iwamoto et al, IEEE Trans. Appl. Superconductivity, Vol 14, No 2, (2004) p 592.

  17. Summary of expected quench limits

  18. Possible experiments on production magnets QH L4 • MQY in B4: • -Use one QH L2-3 for coil • heating • -Magnet protection by • QHL4 • MQM and MQY in SM18: • Use anti-cryostat heaters • to verify operating • margins at 4.5 K QH L2-3

  19. Conclusions • Heat loads associated to pp collisions are considerable in the experimental insertions, in particular in the low-beta triplets. • Thermal properties of the coils of both types of low-beta quadrupoles were experimentally studied, and confirm a safety factor of 3 with respect to expected heat load for nominal luminosity. • MQM and MQY quadrupoles have insulation schemes analogous to the MB. Similar thermal properties could be expected, but have not been experimentally verified. • Magnets operating at 4.5 K are expected to have higher quench limits for transient losses, but lower for continuous losses than at 1.9K.

More Related