Summary of Muon Collider Targetry Workshop, held at BNL, May 1, 1998 K. McDonald, 5/2/98 This note and related images can also be found at http://puhep1.princeton.edu/mumu/target/ The focus of the workshop was discussion towards a proposal to BNL this summer for an experimental R&D program related to muon collider targetry. Attendees: Mike Brennan, Rick Fernow, Yasuo Fukui, Juan Gallardo, Steve Kahn, Bruce King, Harold Kirk, Paul Lebrun, Kirk McDonald, Bob Palmer, Claude Reed, Tom Roser, Yagmur Torun, Bob Weggel, Yongxiang Zhao From 9:00am - 2:30pm there was a series of presentations: K. McDonald: Overview of targetry and phase rotation. B. Weggel: Review of magnet options for the R&D program. B. King: `Bandsaw' target with band moving nearly parallel to solenoid axis T. Roser: AGS upgrades for full turn fast extraction and for 5ns pulses P. LeBrun: Software integration for simulation of targetry and phase rotation Y. Fukui: ICOOL simulation of phase rotation Y. Torun: Analysis of BNL E-910 D. Winn: Liquid xenon jet From 2:30pm on, R. Palmer led a general discussion on the R&D program. The experiments will have 2 main themes: I. Behavior of a liquid jet in a beam and in a magnetic field. II. Behavior of an RF cavity in an intense particle flux, while in a magnetic field I. Liquid jet A. Build jet along design of Colin Johnson Increase diameter from 3 mm to 1-2 cm, if possible Use Ga/In initially (room temperature liquid) B. Test jet in magnet without beam -- study effect of eddy currents Favored option: 20-T magnet facility at FSU C. Test jet in beam (initially without magnet) -- study effect of shock on liquid Preliminary study could be done with liquid in a trough exposed to the beam D. Test jet in beam with magnet (20T desired) Want high proton full => full turn extraction of AGS Vary spot size on target to study effect of very high local energy deposition; sigma_x ~ 1-5 mm. E. Possible preliminary study of shock effects via `exploding wire' II. RF Cavity test A. Desire to study effect of particle flux within a single RF cycle. BNL pulse width likely only 5ns (sigma) => RF frequency < 100 MHz. Option to study flux from full turn extraction of AGS B. Retrieve RF test stand from LBL and modify for lower frequency Do old tetrodes still work? C. Build new RF cavity with folded design to minimize radius; Iris should be close to desired shape at r = 15 cm D. Build/borrow 5T solenoid to surrond cavity. Must be a DC magnet => superconducting. E. Cavity could be very close to BNL target to increase flux to muon collider nominal value III. Beam Requirments A. Primary protons brought to test area in F.E.B. line B. 24 GeV desired -- but would consider lower energy if pulse length significantly shorter (2 ns) C. Desire 10^14 p in single `pulse' -- but 6-8 pulses from a single turn AGS extraction sufficient for many purposes. D. For rf tests, desire single pulse with width less than a single rf cycle, => sigma < 5 ns is use 100 MHz rf. IV Magnet Requirements A. For phase II of target studies, desire target + beam inside a 20-T magnet. B. Magnet can be pulsed, with low rep rep (minutes per pulse) C. Magnet is lighter, simpler if > 10 MW power supply is available. BNL `spare' 30 MW Westinghouse supply is extremely interesting. Backup: build 30 MW supply from `spare' parts at PPPL D. Magnet will likely by LN_2 precooled. IV. Work list The designated people are expected to follow up on the above discussion, make appropriate contacts, and prepare (written) reports the can be incorporated into the forthcoming BNL proposal A. R&D program overview -- K. McDonald B. Liquid Jet -- K. McDonald C. Pulsed magnet -- B. Weggel D. RF cavity -- H. Kirk + BNL rf group E. BNL beam -- T. Roser Left unassigned: simulation V. Next workshop: Monday, June 1, 1998 at BNL The focus of this workshop will be reports on the work list, and further preparation for submission of a proposal in summer '98.