1 / 24

Geant Simulation of Muon Cooling Rings

Geant Simulation of Muon Cooling Rings. Amit Klier University of California Riverside. Outline. A short reminder from Nufact03 The RFOFO ring Geometry Software improvements Simulation results The small dipole ring Geometry Software improvements Some Results. Muc_Geant.

vina
Download Presentation

Geant Simulation of Muon Cooling Rings

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Geant Simulation of Muon Cooling Rings Amit Klier University of California Riverside

  2. Outline • A short reminder from Nufact03 • The RFOFO ring • Geometry • Software improvements • Simulation results • The small dipole ring • Geometry • Software improvements • Some Results A. Klier - Geant simulation

  3. Muc_Geant • Modified, data-driven Geant3 application for simulating muon cooling • Electric fields added • Runge-Kutta changed to include changing electric fields (eg RF cavities) • Realistic magnetic fields can be read from external field maps A. Klier - Geant simulation

  4. From Nuact03 Tetra ring simulated Rajendran Raja – Nufact 03 A. Klier - Geant simulation

  5. The RFOFO ring • A few code changes w.r.t. Tetra • Realistic magnetic field maps read-in (R. Godang, S. Bracker – MC-Note 271) A. Klier - Geant simulation

  6. The RFOFO ring Full Geant simulation: A. Klier – MC-Note 298 A. Klier - Geant simulation

  7. The ring geometry • 33 m circumference • 12 cells (2.75m): • A wedge absorber • opening angle 110°, • pointing ’upwards’ • 6 RF cavities • 28.75 cm long, • iris radius 25 cm • flat E field in z direction • 2 tilted solenoids • inner/outer r = 77/88 cm • tilt angle ±3° • Only for display here A. Klier - Geant simulation

  8. Closed orbits in a single cell Solid line – the referenceorbit 200 MeV 270 MeV 227 MeV 250 MeV 250 MeV 227 MeV E = 200 MeV E = 270 MeV A. Klier - Geant simulation

  9. Software improvements • ICOOL input/output format used, ecalc9 can be used to calculate emittance • Use initial time of particle at entry • Use virtual detectors A. Klier - Geant simulation

  10. Cooling of a muon beam A. Klier - Geant simulation

  11. Comparison with ICOOL Transmission 6-D emittance A. Klier - Geant simulation

  12. More comparisons Results after 10 turns: Merit factor A. Klier - Geant simulation

  13. Change beam entry angle A. Klier - Geant simulation

  14. The small dipole ring “Weak” (edge) focusing (ideally) scaling Filled with ~10 Atm. hydrogen gas @ 77K Dipole field ~ 2 T For P~200 MeV/c, the radius should be ~60 cm A. Klier - Geant simulation

  15. Field map (from S. Kahn) By in a single quadrant By at R=60 cm Return yoke A. Klier - Geant simulation

  16. Reference orbit • Scale B down to 90% • closed orbit: • P=171.25 MeV/c • Rmin=56.32 cm • (x=0 in virtual detectors) Rmin Virtual detector plane RF cavity (active region) A. Klier - Geant simulation

  17. Ellipses Stable up to y~13 cm Y plane symmetry imposed A. Klier - Geant simulation

  18. Acceptance of the ring “A blob” Py=~19 MeV/c y=~8.5 cm Px=~34 MeV/c More “natural” decrease with no x-z plane symmetry x=~6.5 cm A. Klier - Geant simulation

  19. “Cooling” with no scattering Xinitial=6 cm Yinitial=8 cm tinitial= –1.5 ns Xcentral=0.04 cm Ycentral=0 cm tcentral=0 ns PXinitial=30 MeV/c PYinitial=17.5 MeV/c Einitial=213 MeV PXcentral=0.12 MeV/c PYcentral=0 MeV/c Ecentral=201.8 MeV A. Klier - Geant simulation

  20. Software improvements • More flexibility – less “hard-coding”, more external parameters • Field map reading code used to be RFOFO-specific, now more general • More RF parameters • Cavities in small dipole ring are off-center • So far, only perfect pillbox (or flat field..) cavity are simulated • Flexibility: different frequencies, gradients, types can be used in the same channel A. Klier - Geant simulation

  21. To do • Simulate the small dipole ring with a beam • Introduce more realistic features: • Injection • Detectors A. Klier - Geant simulation

  22. A. Klier - Geant simulation

  23. Additional Slides A. Klier - Geant simulation

  24. Comparison with ICOOL Transverse emittance Longitudinal emittance A. Klier - Geant simulation

More Related