1. Overview of BNL’s Accelerator R&D Program Vitaly Yakimenko April 18, 2006 DOE Annual High Energy Physics Program Review Brookhaven National Laboratory

2. Vitaly Yakimenko(2/30) Outline: Superconducting Magnet Division (SMD) Peter Wonder Advanced Accelerator R&D group Robert Palmer Accelerator Test Facility (ATF) Vitaly Yakimenko Accelerator R&D at C-AD

3. Vitaly Yakimenko(3/30) HEP Superconducting Magnet Program 1.ILC Beam Delivery System R&D 2.High Field Magnet R&D 3.Superconducting Materials Development 4.LARP - Magnets

4. Vitaly Yakimenko(4/30) ILC Final Focus Magnet R&D - FY06/07 FY06 accomplishments: Integrated design (beam optics + superconducting magnets) of 14 mrad IR Successful test of coil with active shielding of external magnetic field Measured motion of a cold magnet at the sensitivity needed at the ILC IR. FY07 plans: Start 2m prototype magnet, continue beam optics work, continue vibration studies

5. Vitaly Yakimenko(5/30) High Field Magnet R&D Nb 3 Sn React-and-Wind Common Coil (twin-aperture, 4cm gap) dipole completed and tested. Reached conductor limit, 10 T. React-and-wind can also be used for high temperature superconductor. Program terminated due to lack of funding

6. Vitaly Yakimenko(6/30) Superconducting Materials Development Close collaboration with Materials Science Dept. and industry: materials expertise + magnet expertise Low Temperature Superconductor (LTS) R&D –Nb 3 Sn conductor development –Leading LARP three-lab effort on Nb 3 Sn –MgB 2 wire development High Temperature Superconductor (HTS) R&D –Bi-2223 tape and 2nd –generation YBCO tapes Strain sensitivity: Nb 3 Sn ≈ HTS  Nb 3 Sn experience & equipment useful with HTS.

7. Vitaly Yakimenko(7/30) BNL LARP Magnet Program GOAL: test Nb 3 Sn long racetrack coils and support structure  input to LARP quadrupole design Collaboration: FNAL (manager) + LBNL ( support structure) + BNL (coils) STATUS: 30 cm racetrack coil + support structure ready to test Transfer of “wind and react” technology from LBNL to BNL PLANS: test 3.6 m coils and support structure – December 2006 check effect of lengthening on coil, support structure test additional 3.6 m coil – September 2007 check quad coil construction methods

8. Vitaly Yakimenko(8/30) Summary Magnet program well aligned with the National goals: ILC, LARP. These elements receive direct programmatic funding. Distinguishing features of the program are: –Direct wind technique –HTS development (mostly outside HEP in BES/NP) –Materials expertise –React-and-Wind Nb3Sn development –Full length fabrication and testing Base program support continues to be reduced –High field magnet R&D terminated –Cable testing terminated

9. Vitaly Yakimenko(9/30) Advanced Accelerator R&D Group Working on Neutrino Factory & Muon Collider collaboration (NFMCC): 1.Neutrino Factory & Muon Collider R&D 2.Liquid Target Experiment MERIT Non NFMCC Advanced Accelerator work 3.Solid Target Radiation Studies 4.Fixed Field alternating Gradient (FFAG) Studies

10. Vitaly Yakimenko(10/30) Advanced Accelerator R&D

11. Vitaly Yakimenko(11/30) Advanced Accelerator R&D

12. Vitaly Yakimenko(12/30) Neutrino Factory Design & Simulation (Part of NFMCC) Mainly part of International Scoping Study (ISS) –Comparison of Schemes –Only 201 MHz Study 2A achieves –10 21 mu decays per year goal ISS current leanings: –201 MHz frequency OLD –Proton Energy 10 GeV NEW –5 bunch proton train (0.5 µs sep) –to reduce loading and space charge problems NEW

13. Vitaly Yakimenko(13/30) Liquid Target Experiment MERIT (Part of NFMCC) BNL,MIT,CERN,RAL,Princeton,Oak Ridge Collaboration Harold Kirk is one of two Spokespersons Will expose mercury Jet to CERN proton beam Probably only practical target at 4 MW BNL oversight of 15 T pulsed magnet acquisition Magnet now at MIT for testing - below right Instrumentation Department building Optics system to observe mercury dispersion by beam

14. Vitaly Yakimenko(14/30) Recent progress on MERIT

15. Vitaly Yakimenko(15/30) Advanced Accelerator R&D

16. Vitaly Yakimenko(16/30) Targetry R&D budget Liquid Target Studies$50K – Engineering Support Solid Target Studies$270K – Blip Beam Time – Hot Cell usage – Instrumentation – Materials – Horn/Target design Graduate Student$50K Travel$30K Total$400K The bulk of the resources is placed into our materials/irradiation studies.

17. Vitaly Yakimenko(17/30) Advanced Accelerator R&D

18. Vitaly Yakimenko(18/30) Advanced Accelerator R&D Summary

19. Vitaly Yakimenko(19/30) BNL Accelerator Test Facility - ATF  The ATF is a proposal-driven, advisory committee reviewed USER FACILITY for long-term R&D into the Physics of Beams.  The ATF serves the whole community: National Labs, universities, industry and international collaborations.  ATF contributes to Education in Beam Physics. (~2 PhD / year)  In-house R&D on photoinjectors, lasers, diagnostics, computer control and more (~3 Phys. Rev. X / year)  Support from HEP and BES. The ATF features:  High brightness electron gun  75 Mev Linac  High power lasers beam- synchronized at the picosec level (TW level CO2 laser)  4 beam lines + controls

20. Vitaly Yakimenko(20/30) ATF Statistics Run time: ~ 1000 hour / year Graduated students: 22 Current number of experiments: 14 Staff members: 11, 1 visitor Phys Rev X: ~ 3 / year since 1995

21. Vitaly Yakimenko(21/30) ATF Terawatt CO 2 Laser Story (past and present) 1995 2000 20052010 Inverse Cherenkov accelerator IFEL accelerator Thomson X-ray source HGHG STELLA Ion and Proton source Resonant PWA Seeded LWFA LACARA PASER 3 TW 300 GW 30 GW 3 GW Nonlinear Thomson scattering EUV source

22. Vitaly Yakimenko(22/30) Why we need better emittance ICA IFEL Thomson X-ray source HGHG 1995 1998 20012004 STELLA 4  m 2  m 1  m 0.5  m VISA Dielectric WFA Smith Purcell experiment Micro bunching SASE @1  m Plasma WFA To match laser accelerating or FEL beam and electron beam; or to transport through small (high frequency) accelerating channel

23. Vitaly Yakimenko(23/30) Ion generation experiment

24. Vitaly Yakimenko(24/30) Monochromatic beams with CO2 laser Proton energy spectrum from a structured target. (a) Solid state laser with =1  m. (b) CO2 laser with =10  m. The CO2 laser produces a much narrower proton spectrum because of the narrower phase space fill.

25. Vitaly Yakimenko(25/30) Plasma Wakefield experiments at ATF Multi-bunch Plasma Wakefield Acceleration at ATF, AE31. Spokepersons T. Katsouleas and P. Muggli, Univ. Southern California. Laser Wakefield Acceleration Driven by a CO2 Laser, AE32, Spokesperson W. Kimura, STI Optronics Ion Motion in Intense Beam-Driven Plasma Wakefield (UCLA, J. Rosenzweig) Plasma density measurement 10 16 -10 19 by Stark broadening

26. Vitaly Yakimenko(26/30) Beam splitting during compression Interaction of the Coherent Synchrotron Radiation (CSR) with the beam itself leads to energy modulation along the beam. It produces two distinct beams (due to two stages of compression: chicane and dog-leg) very useful for some experiments at ATF (two beam PWA). X band linac section is needed to deliver clean, low energy spread compressed beam to user experiments Structure is available, ATF has a spare modulator, SLAC needs $350K to manufacture X-band klystron for ATF Three experimental groups will immediately benefit. Chicane Dog-leg Linac Experimental beam line Spectrometer E E ~2% x-band

27. Vitaly Yakimenko(27/30) Optical Stochastic Cooling It is feasible to cool gold and protons beams at full energy in RHIC and possibly Pb at LHC with multistage optical amplifier. Optical parametric amplifier based on CaGeAs was suggested and experimentally tested at ATF Bypass experiment with electron beam at ATF –Will prove lattice control, optical amplifier and adequate diagnostics –It is similar to previously successful at ATF staged laser accelerator (STELLA and STELLA II) experiments. –requires dedicated manpower.

28. Vitaly Yakimenko(28/30) Polarized Positron Source (PPS) summary Compton back-scattering based PPS is a backup scheme for ILC and the only choice for CLIC We propose Compton-based PPS inside optical cavity of CO 2 laser beam and 6 GeV e-beam produced by linac. The proposal utilizes commercially available units for laser and accelerator systems. The proposal requires high power picoseconds CO2 laser mode of operation developed at ATF. (ATF is the only facility in the world with operational Joule/picosecond CO2 laser system.) 3 year laser R&D is needed to verify laser operation in the non standard regime.

29. Vitaly Yakimenko(29/30) Conclusion The experimental program at ATF is strong, broad and relevant to HEP It is aimed at near, intermediate and long term accelerator R&D: –Beam brightness, compression (LCLS) –Polarized Positron Source (ILC and CLIC) –Optical Stochastic Cooling (RHIC and LHC upgrade) –Beam and laser based Plasma Wakefield Accelerators (PWA), ion movement in the PWA (ILC upgrade) –Laser based accelerators (post ILC) –Compact, high brightness laser based proton, ion and neutron sources (medical applications, injector, security…) ATF plays important role in education of accelerator scientists The support and progress of the user experiments is seriously limited by the accelerator staff level

30. Vitaly Yakimenko(30/30) Accelerator R&D at C-AD from V. Litvinenko (non HEP funding) High current super-conducting energy recovery linacs (ERL) High current super-conducting RF guns Generation and transport of ultra-high brightness electron beams in ERLs Secondary emission (diamond) photo-cathodes High energy electron cooling of ions and protons in collider mode Stochastic cooling of bunched beams Development of polarized SRF electron gun (with MIT) Development of FFAG (fixed-filed alternating-gradient) accelerator lattices for protons and ions Development of rapid cycling proton synchrotron for medical applications