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Simulations of Muon Cooling With an Inverse Cyclotron. Introduction G4beamline Work ICOOL Work Plans and Goals. Introduction. Started new appointment with U. of Mississippi Don Summers is my boss I’ll be working on MICE MuCool Inverse cyclotron simulation working with
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Simulations of Muon Cooling With an Inverse Cyclotron • Introduction • G4beamline Work • ICOOL Work • Plans and Goals Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Introduction • Started new appointment with U. of Mississippi • Don Summers is my boss • I’ll be working on • MICE • MuCool • Inverse cyclotron simulation working with • Kevin Paul from Tech-X • Kevin Beard from JLab.; Muons, Inc. • Bob Palmer from BNL Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Introduction • Inverse cyclotron intriguing scheme for 6D muon cooling • Inverse Cyclotron Scheme • Muon beam injected into cyclotron • Lose energy through material interactions • material wedges surrounded by gas • Mid-plane foil relying on betatron oscillations • Focus beam with sectored (straight or spiral) magnetic field • Cooled muon beam coalesces at cyclotron center into one bunch • Muon bunch extracted perpendicular to cyclotron Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Introduction • Inverse cyclotron illustration of energy loss injection • ICOOL simulation from Bob Palmer • Lithium hydride wedges • 4 sectors, 1.8 T, soft edged magnetic field • Three 172 MeV/c muons Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Introduction • References • 6D Muon Ionization Cooling with an Inverse Cyclotron from COOL 05; Summers, Bracker, Cremaldi, Godang, Palmer (2005) • Focusing Properties of Superconducting Cyclotron Magnets, NIM 121, Blosser and Johnson (1974) • Handbook of Accelerator Physics and Engineering, edited by Chao, Tigner • Introductory Nuclear Physics, Krane Terry Hart, U. of Mississippi., Muon Collider Design Workshop
G4beamline Work • Don sent me program generating Bz of spiral sector cyclotron • Number of sectors • Spiral angle • Bz,high, Bz,low • Transition regions • Between sectors • Z bottle • G4beamline can import field from text file • I wanted to generate stable orbits from trial/error and calculation • No beam energy, angular spreads • No energy loss Terry Hart, U. of Mississippi., Muon Collider Design Workshop
θ1 + θ2 = 60º sin(θ1/2) = (r2/r1) × sin(θ2 /2) = 4 × sin(θ2 /2) r1 = (50 MeV)/(e × c × 2 T) = 83.33 mm r2 = (50 MeV)/(e × c × 0.5 T) = 333.33 mm Numerical evaluation of angles, lots of algebra yield rmin = 191.85 mm rave = 202.91 mm rmax = 214.62 mm θ2 r2 θ1 r1 rmax rave rmin Bz = 2 T Bz = -0.5 T Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Plugging Calculated Orbit into G4beamline • Simulation pretty close to calculation • ~40 orbits before escape • Red dashed line: calculated rave • Why not exact closed orbit? • Probably due to G4beamline linear field interpolation between grid points “fields not symplectic”? Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Try Energy Loss With Hydrogen Gas • Add 0.001 g/cm3 hydrogen gas • Two particles • Spiral in (good) • Escape (bad) • Refine by • varying gas pressure vs. radius in accordance to dE/dx vs. momentum • And/or add lithium hydride wedges Terry Hart, U. of Mississippi., Muon Collider Design Workshop
What’s Needed to Go On • Focusing in cyclotron plane needs azimuthal (Bx, By) fields • Much harder than Bz, but programs available • Use soft-edged fields instead of hard-edged fields • Energy loss • Hydrogen gas of varying densities • Lithium hydride wedges Terry Hart, U. of Mississippi., Muon Collider Design Workshop
ICOOL Work • Bob Palmer sent me zip file with input, output files of inverse cyclotron simulation • I’ve been studying ICOOL files, ICOOL User’s Guide, and ICOOL Reference Manual • Really close to reproducing output. • Would like to further develop ICOOL inverse cyclotron simulations • Inverse Cyclotron Illustration • ICOOL simulation • Lithium hydride wedges • 4 sectors, 1.8 T, soft edged magnetic field • Three 172 MeV/c muons Terry Hart, U. of Mississippi., Muon Collider Design Workshop
Plans and Goals • Continue learning more accelerator physics, G4beamline, ICOOL, … • Learn more about sector cyclotron magnetic field programs • Existing field in ICOOL simulations • TOSCA, TRIUMF CYCLOPS, … • Develop inverse cyclotron simulations with G4beamline and ICOOL • Find out what’s already known and developed so that I don’t do too much redundant studies • Keep working with Don, Kevin, Kevin, Bob, Rick, and others on developing inverse cyclotron simulations for muon cooling Terry Hart, U. of Mississippi., Muon Collider Design Workshop