Fermilab Accelerator Physics Center Optimization of BeamTarget parameters

Fermilab Accelerator Physics Center Optimization of Beam/Target parameters for g-2 Sergei Striganov g-2 Beam Meeting Fermilab February 29, 2012

Simulation setups: current target and cylindrical inconel target. Proton beam – 0. 3 mm mrad rms emittance and rms beam size – 0. 15 and 0. 55 mm. g-2 beam meeting – Fermilab, Feb. 28, 2012 Optimization of Beam/Target parameters for g-2 S. I. Striganov 2

Figure of merit Pion production on lens, collimator and Pmag is not small. Number of pion inside aperture is not good parameter for optimization, at least in places where primary proton beam can interact with channel elements Mokhov proposed to use number of pion produced from target. He obtained 2. 9 10 -5 π+ /POT for ∆p/p=0. 01 after PMAG coming from target (4 10 -5 total) More precise estimate could be reached by using pion yield in acceptance of pion channel. Simulations were performed for 40 mm mrad acceptance. g-2 beam meeting – Fermilab, Feb. 28, 2012 Optimization of Beam/Target parameters for g-2 S. I. Striganov 3

Current target/default proton beam g-2 beam meeting – Fermilab, Feb. 28, 2012 Optimization of Beam/Target parameters for g-2 S. I. Striganov 4

Current and cylindrical target/small radius proton beam g-2 beam meeting – Fermilab, Feb. 28, 2012 Optimization of Beam/Target parameters for g-2 S. I. Striganov 5

Number of positive pion with ∆p/p=0. 02 after PMAG total From target Acceptance Current target, σ=0. 55 mm 8. 7 10 -5 6. 2 10 -5 2. 1 10 -5 Current target, σ=0. 15 mm 9. 3 10 -5 6. 5 10 -5 3. 2 10 -5 Inconel target, σ=0. 15 mm 11 10 -5 7. 7 10 -5 3. 9 10 -5 Inconel target, 9. 4 10 -5 σ=0. 15 mm, vacuum 9. 4 10 -5 5. 9 10 -5 Mokhov - 2011 5. 8 10 -5 8. 10 -5 g-2 beam meeting – Fermilab, Feb. 28, 2012 Optimization of Beam/Target parameters for g-2 S. I. Striganov 6

CONCLUSIONS 1. Pion yield dependence on beta-function at different places for pion acceptance of 40 mm mrad was simulated for different setups. 2. Yield after PMAG with current pbar target rises on about 50% with decreasing proton beam rms from 0. 55 to 0. 15 mm. 3. Yield after PMAG could be increased on about 20% in comparison with current pbar target by using simple inconel cylinder. 4. Yield nearly linearly depends on momentum bin value. 5. With inconel target (89 mm length and 0. 45 radius) and 8 Ge. V proton (0. 3 mm mrad rms emittance and σ =0. 15 mm) pion yield after PMAG is 3. 9 e-5/POT for ∆p/p=0. 02 and 40 mm mrad acceptance. g-2 beam meeting – Fermilab, Feb. 28, 2012 Optimization of Beam/Target parameters for g-2 S. I. Striganov 7