160 likes | 272 Views
Toward a Test Facility for an ERL Circulator Ring Based e-Cooler. MEIC Electron Cooler Test Facility Planning Retreat January 31, 2012. Charge of the Retreat. Examine the feasibility of utilizing JLab FEL Facility for a test bad of ERL-Circulator-Ring e-cooler
E N D
Toward a Test Facility for an ERL Circulator Ring Based e-Cooler MEIC Electron Cooler Test Facility Planning Retreat January 31, 2012
Charge of the Retreat • Examine the feasibility of utilizing JLab FEL Facility for a test bad of ERL-Circulator-Ring e-cooler • Determine the goals of this test facility • Formulate plausible test scenarios • Determine the required pre-R&D • Draft a plan for this test facility
What We Want to Test/Demonstrate/Study? • Production of high current/bunch intensity, high repetition beam • Energy recovery of a high current electron beam after its extended stay in a circulator ring; • Operation of a circulator ring including injection and ejection of the beam bunches, and advanced filling schemes; • Quality of the beam bunch during a large number of circulations in a ring • Collective beam effects (space charge, CSR)
e-Cooler Test Facility Cooling channel solenoid lattice Diagnostic element Fast kicker Fast kicker
Scaling Down Parameters: How Much? For a convincing demonstration • Beam current in circulator ring: 1.5 A 15 mA ? • Charge per bunch: 2 nC 0.4 nC ? • ERL beam current: 15 mA 15 mA ? • Fast kicker: 1.33 ns (750 MHz) 20 ns (50 MHz) ? • Turns of circulation: 10 to 30 turns ?
Test Scenarios • Test high bunch charge injector (DC gun? SRF gun?) • Test high current ERL without/with circulator ring? • Test kicker/filling scheme of a circulator ring? • Test beam stability/collective effects in circulator ring?
Additional Hardware & pre-R&D • Magnetic lattice for the circulator ring • Fast kickers • Beam diagnostic instruments • High bunch intensity electron source • ERL for high bunch intensity beam (?) • (not very fast) kicker • Design and simulation
Timeline • Total time: 2 years (?) • Design/simulation/pre-R&D: 1.5 year • commissioning: 2 months • Running experiments: 4 months
A Polarized Ring-Ring MEIC at JLab Pre-booster (up to 3 GeV) Ionsource Large booster to collider ring transfer beamline Large booster (warm) (up to 20 GeV/c) SRF linac Ion collider ring (cold) • (up to 100 GeV/c) Three Figure-8 rings stacked vertically Medium energy IP with horizontal crab crossing Electron ring (3 to 11 GeV) Injector 12 GeV CEBAF Future energy/luminosity upgrade possible (250 GeV proton, 100 GeV/u ion, 1035 cm-2s-1)
Optimized Location of Cooling Channel 20 m Solenoid (15 m) injector SRF Short circulating beam-line Center of Figure-8 dumper • Eliminating a long circulating beam-line could • cut cooling time by half, or • reduce the cooling electron current by half, or • reduce the number of circulating by half
Cooling in Ion Collider Ring • Initial cooling after ions injected into the collider ring for reduction of longitudinal emittance before acceleration • After boost & re-bunching, cooling for reaching design values of beam parameters • Continuous cooling during collision for suppressing IBS, maintaining luminosity lifetime BetaCool Simulations In collision mode of MEIC, 60 GeV proton emittance IBS growth time
Monitoring Bunch Evolution in Circulator Ring Cooling channel solenoid lattice Kicking bunches out after n-th turn Fast kicker Fast kicker Diagnostic element Diagnostic element