1. PROTON LINAC FOR INDIAN SNS Vinod Bharadwaj, SLAC (reporting for the Indian SNS Design Team)

2. CENTRE FOR ADVANCED TECHNOLOGY, INDORE DAE lab, SLAC size in people, area New lab built 1987 for accelerator & laser R&D Presently has 450 MeV electron ring (INDUS-1) for synchrotron light R&D, accelerators for industrial use R&D In the process of building 2.5 GeV synchrotron radiation facility (INDUS-2), to start operations in 2004

3. CENTRE FOR ADVANCED TECHNOLOGY, INDORE CAT is the lead $50M collaboration with LHC to build superconducting correction magnets Has a lot of internal expertise in building equipment for accelerators Indian Government is interested in accelerator facilities and international collaborations (meeting in Delhi in Nov 2003, where this was emphasized in person by the Secretaries of DST and DAE)

4. INDIAN INTEREST IN HIGH INTENSITY PROTONS Indian Government is interested in protons –Accelerator Driven Sub-critical Systems burning thorium for energy production –Accelerator Driven Transmutation of Waste Indian Spallation Neutron Source –Part of long range plan –Basic research + ADS R&D –100 kW power initially –Injector is 100 MeV proton linac

5. Accelerator Driven Sub-critical Systems

6. ADSS MOTIVATION

7. CONCEPTUAL ADSS FACILITY

8. ISNS Layout

9. ISNS Parameters

10. Design Specifications of 100 MeV H– Linac Input energy 4.5MeV Output energy 100MeV Beam current 25mA Particles H- Operating mode Pulsed Pulse duration 500  sec Repetition rate 25Hz Linac Design dominated by the need to Reduce beam losses to reduce heating and activation Injector needs to be capable CW operation for injection into future SC linac Injector needs to be upgradeable to higher current for future ISNS upgrade

11. ION SOURCE

12. Low Energy Beam Transport Provides transverse phase space matching between ion- source and RFQ Chops beam for matching into RFQ buckets Use codes TRACE3D & IGUN for optimization

13. RFQ Design Use design code PARMTEQM for particle transmission and SUPERFISH for cavity design Two designs.. –25 mA, lower vane voltage, lower beam losses, better for higher duty factor/CW operations –50 mA for pulsed operations, can use higher vane voltages for better beam properties –Plan is to build 25 mA first to get experience and then upgrade to 50 mA when needed –Calculations show 96.3 % transmission efficiency

14. PROTOTYPE RFQ

15. RFQ Design Parameters

16. MEBT Design Consideration It is very essential to match the beam from one accelerating structure to the next one to avoid the formation of beam halo and emittance blow up and subsequent beam loss. The MEBT provides necessary matching between RFQ and the following drift tube linac. The matching in three phase planes is studied by TRACE3D. The MEBT section uses four quadrupoles, two RF gaps and a combination of drift spaces for matching in transverse and longitudinal planes. The design goal was to obtain the mismatch factors below 0.01 in all the three phase planes.

17. Drift Tube Linac Use DTL structure for accelerating from 4.5 MeV output of RFQ to 100MeV injection into the SNS proton synchrotron, operating at 350 MHz Accelerating gradient ramped from 1.8 MV/m to 2.2 MV/m from tank 1 to tank 2 and then held at 2.2 MV/m Possibility to use S(eparated function) DTL structures for the higher (50 MeV) energies. Tradeoff between ease of manufacture and beam quality being calculated 7 tanks, tanks 3-7 the drift tubes have face angle for improved shunt impedance Drift bore is 1 cm throughout the linac

18. Drift Tube Linac http://www.sns.gov/projectinfo/operations/training/lectures/DTL_101.pdf

19. DT and Tank details for Tank-1 and Tank-2

20. DT and Quadrupole details for Tanks-3 to 7

21. Beam Transmission through DTL

22. Beam Phase Space at End of DTL

23. High power pulsed klystron Frequency of operation350MHz +/- 2.5MHz Output peak power1MW or 2MW Output RF pulse duration700 microsecs Gain43dB Maximum drive power200W Efficiency60 % Output waveguideWR 2300 Focusing Electromagnet

24. CONCLUSION India has ambitious plans for high intensity proton beams, for SNS & ADSS A design for a 100 MeV, 25-50 mA H- minus linac exists SNS project approved in principle and design efforts are underway