DESIGN OF THE BNL SUPER NEUTRINO BEAM FACILITY W. T. Weng Brookhaven National Laboratory Neutrino Super Beam, Detectors and Proton Decay BNL/UCLA/APS Workshop March 3-5, 2004, BNL

OUTLINE A. AGS Operation with protons B. Accelerator Upgrade (1MW) C. R&D Activities D. Accelerator System Cost Estimate E. Further Upgrade Potential F. Conclusion

AGS Intensity History 1 MW AGS

Total Accelerated Protons at the AGS 0.8     Total accelerated protons 1.0   Slow extracted beam (Kaon decay) Fast extracted beam (g-2) Note: Lower total accelerated protons in later years due to much shorter running time

Transition Time to Restore HEP

Concurrent HEP Operation with RHIC 1. From the performance data shown, it is clear that it is possible to operate AGS proton-based HEP research in concurrence with RHIC operation. 2. The available AGS HEP running is about 80% of the total RHIC operation time. 3. The HEP program only have to pay for incremental costs, which is a big savings from independent operation. 4. The co-existence of HEP and RHIC operations is very beneficial for both equipment reliability and personnel training.

AGS Upgrade to 1 MW 200 MeV Drift Tube Linac BOOSTER High Intensity Source plus RFQ Superconducting Linacs To RHIC 400 MeV 800 MeV 1.2 GeV To Target Station AGS 1.2 GeV  28 GeV 0.4 s cycle time (2.5 Hz) 0.2 s 200 MeV l 1.2 GeV superconducting linac extension for direct injection of ~ 1  protons low beam loss at injection; high repetition rate possible further upgrade to 1.5 GeV and 2  protons per pulse possible (x 2) l 2.5 Hz AGS repetition rate triple existing main magnet power supply and magnet current feeds double rf power and accelerating gradient further upgrade to 5 Hz possible (x 2)

AGS Upgrade AGS presentAGS upgrade Kin. Energy28 GeV Rep. Rate1 / 3 Hz2.5 Hz Protons/ Cycle 0.67 x x Ave. Power0.10 MW1.0 MW 1.5-GeV Booster 200-MeV TDL 28-GeV AGS HI Tandem 1.2 GeV SCL 0.6 sec 2.4 sec AGS Booster 0.4 sec Typical DTL cycle for Protons 1 x mA

AGS Proton Driver Parameters present AGS1 MW AGS2 MW AGSJ-PARC Total beam power [MW] Injector Energy [GeV] Beam energy [GeV] Average current [  A] Cycle time [s] No. of protons per fill0.7     Average circulating current [A] No. of bunches at extraction No. of protons per bunch1     No. of protons per 10 7 sec.3.5     10 20

Layout of the 1.2 GeV SCL

1.2 GeV Superconducting Linac Beam energy 0.2  0.4 GeV0.4  0.8 GeV0.8  1.2 GeV Rf frequency805 MHz1610 MHz1610 MHz Accelerating gradient10.8 MeV/m23.5 MeV/m23.5 MeV/m Length37.8 m41.4 m38.3 m Beam power, linac exit17 kW34 kW50 kW Based on SNS Experiences

C. R&D Activities 1. Beam Dynamics in the AGS n Injection Painting n Linac Emittance n Transition Crossing n Ring Impedances n Beam Loss and Collimation 2. AGS Magnet Test 3. New Power Supply Design 4. AGS RF Cavity/Ferrite Test 5. SCL Accelerating Cavity (Join the US SMTF Program) 6. LLRF for Beam Control 7. Design of the 1MW Target/Horn System 8. Target Material Testing (Initiate the US/Japan Collaboration and the BNL LDRD Program)

Beam Loss at H - Injection Energy AGS BoosterPSR LANLSNS1 MW AGS Beam power, Linac exit, kW Kinetic Energy, MeV Number of Protons N P, Vertical Acceptance A,   m  2  N P /  2  3 A),   m Total Beam Losses, % Total Loss Power, W Circumference, m Loss Power per Meter, W/m

AGS Injection Simulation Injection parameters: Injection turns360 Repetition rate2.5 Hz Pulse length1.08 ms Chopping rate0.65 Linac average/peak current20 / 30 mA Momentum spread  0.15 % Inj. beam emittance (95 %)  m RF voltage450 kV Bunch length85 ns Longitudinal emittance1.2 eVs Momentum spread  0.48 % Circ. beam emittance (95 %) 100  m

Halo in AGS as Function of Linac Emittance For acceptable operation, the linac emittance has to be less than 1.5 

Options Layout

Linac Emittance Improvement Emittance at source 0.4 pi mm mr (rms,nor)

New AGS Main Magnet Power Supply presently: l Repetition rate2.5 Hz1 Hz l Peak power110 MW 50 MW l Average power4 MW 4 MW l Peak current5 kA 5 kA l Peak total voltage  25 kV  10 kV l Number of power converters / feeds62

Eddy Current Losses in AGS Magnets For 2.5 (5.0) Hz: In pipe: 65 (260) W/m In coil: 225 (900) W/m

AGS RF System Upgrade Use present cavities with upgraded power supplies UpgradePresent Rf voltage/turn 0.8 MV 0.4 MV RF voltage/gap 20 KV 10 KV Harmonic number 24 6 (12) Rf frequency 9 MHz 3 (4.5) MHz Rf peak power 2 MW 0.75 MW Rf magnetic field18 mT 18 mT 300 kW tetrodes/cavity 2 1

Meeting on the SRF Module Test Facility (SMTF) February 23, 2004 Argonne National Laboratory Agenda AttendeesAttendees, 40 people from 10 U.S. Laboratories Chair: Kwang-Je Kim IntroductionIntroductionH. Edwards Gaps in Knowledge and CapabilitiesGaps in Knowledge and CapabilitiesH. Padamsee

MATERIAL STUDIES FOR PULSED HIGH-INTENSITY PROTON BEAMS TARGET-HORN R&D Nicholas Simos, Harold Kirk, Hans Ludewig, Peter Thieberger, W-T Weng BNL Kirk McDonald, Princeton U K. Yoshimura, KEK J. Shepard, SLAC J. Hylen, FNAL

PHASE-II TARGET MATERIAL STUDY WHAT’S NEXT ? PERFORM irradiation and assess mechanical property changes for a host of baseline materials. Perform more sophisticated assessment Carbon-Carbon composite This low-Z composite gives the indication that it can minimize the thermal shock and survive high intensity pulses. Because of its premise it is the baseline target material for the BNL neutrino superbeam initiative. The way its key properties (such as CTE or strength) degrade with radiation is unknown. Titanium Ti-6Al-4V alloy The evaluation of the fracture toughness changes due to irradiation is of interest regarding this alloy that combines good tensile strength and relatively low CTE Toyota “Gum Metal” This alloy with the ultra-low elastic modulus, high strength, super-elastic like nature and near-zero linear expansion coefficient for the temperature range -200 o C to +250 o C to be assessed for irradiation effects on these properties. VASCOMAX This very high strength alloy that can serve as high-Z target to be evaluated for effects of irradiation on CTE, fracture toughness and ductility loss AlBeMet A low-Z composite that combines good properties of Be and Al. Effects of irradiation on CTE and mechanical properties need to be assessed TG-43 Graphite Possibly Nickel-plated Aluminum T6061 (Horn material) for visible irradiation/corrosion effects, loss of electrical conductivity, delamination, etc.

Preliminary Cost Estimate of the BNL - SNBF Accelerator Systems 1.2 GeV SC Linac: Front End$ 2.5 M LE SC Linac$ 38.3 M ME SC Linac$ 30.7 M HE SC Linac$ 28.1 M AGS Upgrades: AGS Power Supply$ 32.0 M AGS RF Upgrade$ 8.6 M AGS Injection Channel$ 3.7 M Full Turn Extraction$ 5.5 M Shielding$ 3.2 M Direct Cost$156.8 M Total Direct Cost = $156.8 M$

Preliminary Cost Estimate – Continued Total Direct Cost = $156.8 M Add:ED&I, 15% Contingency, 30% BNL Project Overhead, 13% Total Estimated Cost = $265 M

Conclusions 1.The feasibility has been demonstrated for a 1MW upgrade for the AGS 2.It is possible to further upgrade the AGS to 2 MW 3.Active R&D efforts are in progress to improve on the design and reduce cost. 4.Such a high power proton driver is essential for very long base line neutrino experiment and also for the neutrino factory.