DTL & CCDTL (& PIMS?) EMQs

1. DTL & CCDTL (& PIMS?) EMQs Th. Zickler CERN

2. Outlook • History • Requirements and constraints • Proposed quadrupole layout • Magnet field characteristics • Power requirements • Dynamic behaviour • Eddy currents • Conclusions and next steps

3. History Baseline: A common quad type for entire Linac (DTL, CCDTL, SCL) Beginning 2007: 2 Quad types combined with steerer (DTL, CCDTL & PIMS) due to restricted space End 2008: One common quad type for entire Linac (DTL, CCDTL, PIMS) and separate steerers Summer 2009: Review: further space restrictions require new solutions; management proposal to replace CCDTL intertank EMQs with PMQs

4. Design Requirements and Constraints General common requirements: • Operation modes: • Linac4 operation: 1 Hz, 400 µs stable flat top • Low Power SPL operation: 2 Hz, 1000 µs stable flat top • Power converter: • Fast pulsed power converters (200 A / 1000 V) • Maximum flat top duration: 2 ms • Eddy currents? Flat top stability (1000 ppm) • Restricted space: • allows only air cooling (natural convection) • Limited current densities (< 2 A/mm2) • Field quality: • Field homogeneity inside GFR: < 5*10-3

5. Design Requirements and Constraints DTL specific requirements: • 2 quadrupoles • Restricted space: • in particular intertank DTL 1-2 • Overall length: < 106 mm • Width: no severe restrictions • Pick-up inside magnet: • Aperture radius: 20 mm  27 mm • Magnetic field requirements: • Max. integrated field gradient: 2.2 T

6. Design Requirements and Constraints CCDTL specific requirements: • 14 + 7 quadrupoles • Restricted space: • in particular intertank • Overall length: < 198 mm (?) • Overall radius: < 112 (140) mm • Aperture: • Radius: 20 mm • Magnetic field requirements: • Max. integrated field gradient: 1.8 T No CCDTL prototype drawing available

7. Design Requirements and Constraints PIMS specific requirements: • 12 quadrupoles • Restricted space: • Similar to DTL • Overall length: < 106 mm (?) • Width: no severe restrictions • Aperture: • Radius: 20 mm • Magnetic field requirements: • Max. integrated field gradient: 1.7 T

8. Design Requirements and Constraints Summary (‘smallest common denominator’): • 35 quadrupoles • Restricted space: • Overall length: < 106 mm • Overall radius: < 112 (140) mm • Aperture: • Radius: 27 mm • Magnetic field requirements: • Max. integrated field gradient: 2.2 T

9. Proposed Quadrupole Layout

10. Magnetic Field Quality Goodfieldradius: 18 mm 2D fieldquality (gradient): +5*10-3 / -7*10-3

11. Magnetic Field Quality Magnetic Field Quality

12. 3D Design

13. Power Requirements

14. Dynamic Behavior Linac4 Ramp time: 500µs dI/dt: 180 kA/s Stable flat top: 400µs Low Power SPL Ramp time: 200µs dI/dt: 450 kA/s Stable flat top: 1000µs

15. Eddy Currents Ramp time: 500 µs Material: 316 LN Wall thickness: 2 mm Eddy currents in vacuumchamber and pick-up

16. Eddy Currents Time constant: < 50µs Stable (< 10-3) after 100 µs No significant heating

17. Conclusions and Next Steps • Solution found: one design for all Linac parts • Proposed design fullfills the requirements and constraints, in particular the required dimensional limitations • No problems from eddy currents in vacuum chamber and PU expected • Total flat top of 2 ms required for field stability

18. Conclusions and Next Steps • Clarification needed: • Available space (DTL, CCDTL, PIMS) • Confirmation of aperture size • Pick-up design • Power converter: inductance, ramp rate, voltage....? • Interference with other equipment • Next steps: • Layout integration • Pole optimization • 3D calculations to study end field effects (shims) • Possible field distortions