Task7: NUSTAR2 - Design and Prototype Construction of a Radiation-Resistant Magnet

1. Task7: NUSTAR2 - Design and Prototype Construction of a Radiation-Resistant Magnet C. Mühle GSI Task leader: G. Moritz /GSI

2. High-radiation area Design parameters and layout of the Super-FRS

3. Participating institutes in task7 (NUSTAR2)

4. Multi-annual implementation plan for NUSTAR2

5. Material properties: Exploration of radiation load on magnets behind the high-power production target • 3 different aspects of energy deposition • Quench limit (2-3mJ/g): close to limit • Material life time (see table): mineral insulation required • Cooling requirements (expected FAIR cryogenic power: 20 kW): economic operation not possible • Decision • Normal conducting magnets with mineral insulated cable (MIC) Energy deposition distribution (calculated with PHITS) Projectile: 1500 MeV/u 238U 1012/s σx = 1.0 mm σy = 2.0 mm σp /p = 0.5% Target: Carbon 4 g/cm2 • Average energy deposition on on the coil surface:<ΔE>/M ≈ 1 mJ/g • Equivalent to 14 MGy/a (4000h/a operation ) • Heat load on the cryogenic system for a 5 ton quadrupole magnet: ≈ 2.3 kW Material properties:

6. Mineral insulated cable (MIC) • Potential suppliers • Hitachi, Japan • Kirscable, Russia • Tyco Thermal Controls, Canada • Copper conductor with and w/o cooling channel • Rated up to 3000 A (engineering current density 3-6 A/mm2) • Expected cable costs ≈150€/m

7. Magnets with MIC • New technology for GSI -> investigation of feasibility for all magnets potentially to be build with MIC • 11° dipole (3 units) • Quadrupole with 10cm aperture radius (2 units) • Quadrupole with 20cm aperture radius (1 units) • Sextupole (2 units) • Conceptual designs for all magnets were prepared (additional collaboration work with P.Vobly (BINP) is appreciated) • Direct cooling vs. indirect cooling was investigated • Indirect cooling is favorable • Cooling circuit and electrical circuit are separated -> no copper corrosion in the high radiation field • Engineering current density is higher • Conductor end plugs easier to be made • Separation of water and current terminals to one end of the magnet, each • Parameters of cooling circuit are independently from electrical circuit • Use of one conductor cross section for all magnets probable

8. Example: Quadrupole with 10cm aperture radius • Indirectly cooled • Cable 14x14mm • Copper cross section 9x9mm • Current 1100A • 170kW • Directly cooled • Cable 19.8x19.8mm • Copper cross section 14.5x14.5mm • Cooling channel 7.3x7.3mm • Current 1900A • 240kW Sizes are comparable!

9. Half yoke weight: 43 tons Example: Dipole • Indirectly cooled • Laminated magnet • Pole shims for improved field quality • Bent magnet under investigation Cooling terminals Electrical terminals

10. Example: Sextupole • Indirectly cooled • Laminated magnet

11. Surveying and alignment system for high-radiation areas • Remote-controlled camera vehicle in tunnel or on working platform • Eccentric photogrammetric targets on magnets • Sequential photogrammetric survey of inaccessible areas during shutdown • Bundle adjustment of photogrammetric network • Determination of correction values for magnet positions • Automatic, remote-controlled adjustment of machine geometry

12. Surveying and alignment system for high-radiation areas Work packages • Development of basic concept (photogrammetric solution) • Evaluation of camera specs; geometric camera tests • Design of algorithms for image analysis • Simulations of potential camera configurations • Camera tests at radioactive environments • Evaluation of constraints for accelerator design • Evaluation of criteria for automatic remote adjustment • Concept for integration in accelerator operation Most of the work packages ( ) are still in process since planning of accelerator design is not finished yet