Some Proposals for ILC Beam Test Facilities at

Some Proposals for ILC Beam Test Facilities at FNAL Mike Church ILC R&D Meeting 4/19/06 1

Where Did This Come From? -- Agenda and Attendees for Initial Discussions on Beam Facilities – 3/14/06 Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 2

5 Tiered Proposals Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 3

Beam Test Facilities and What Can Be Learned from Them Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 4

Flat Beams from Photoinjector A 0 photoinjector - comment ILC bunch charge (n. C) up to 16 3. 2 bunch spacing (nsec) 1000 330 RF pulse length (ms) up to. 6 new gun design required to prevent overheating and breakdown pulse repetition rate (Hz) 1 requires RF upgrade to increase rep. rate normalized horizontal emittance (mm-mrad) 40 (@ 0. 5 n. C) 8 (DR extraction); 10 (IP) normalized vertical emittance (mm-mrad) . 4 (@ 0. 5 n. C) . 02 (DR extraction); . 04 (IP) emittance ratio 100 (@ 0. 5 n. C) 400 (DR extraction); 250 (IP) RMS bunch length after bunch compression (mm) . 5 (@1 n. C) . 3 RMS momentum spread after compression (%) ~4 (@1 n. C) 1. 1 polarized? no R&D in progress -- vacuum issues may be difficult Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 1 5 yes 5

ILCTA @ New Muon Lab round to flat beam transformation (will be 3) P. Piot Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 6

Emittance Evolution in the ILC Main Linac § § Lattice is “BCD” with 1 Quadrupole per 4 Cryo Modules. Length of a FODO cell is 86 m. Number of cells is 114 Initial Beam Energy is 15 Ge. V, final 250 Ge. V Initial Vertical Normalized Emittance is 20 nm*rad The plot shows that large emittance growth occurs in the first 10 FODO cells (~1 km length), even with all steering algorithms applied (both 1 -1 steering and Dispersion Free steering applied). Projected vertical emittance, using MATLIAR A. Valishev Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 7

Emittance Evolution in a Model Test Facility Linac Projected vertical emittance, using MATLIAR § § Simple model of a Test Linac: 10 FODO cells of ILC (~1 km) Initial Beam Energy is 100 Me. V, final energy 23 Ge. V Initial Vertical Normalized Emittance is 20 nm*rad With nominal element misalignments and no steering applied the emittance growth of 2 orders of magnitude is observed A. Valishev Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 8

Civil Construction Issues (5 Ge. V linac) A 5 Ge. V linac should duplicate as much of the ILC infrastructure as possible: § 2 tunnel design § identical RF and cryo distribution systems § 1 cryoplant/service building § large access shaft plus emergency egress paths § vertical curvature Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 9

Possible Location of 500 m Linac Inside Tevatron Ring 500 m linac C 0 collision hall approximate site of PD Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 10

A Survey of e- Rings e- Ring Energy (Ge. V) Circ. (m) Bunch Int. (E 10) # Bunches Beam Current (A) ILC 5. 0 6000 2 2820 0. 451 CESR-C 5 768 1. 2 40 0. 03 KEKB (HER) 8 3016 6 1388 1. 35 PEP-II (HER) 9 2200 4. 6 1230 1. 23 HERA 30 6336 3 189 0. 043 VEPP-4 M 6. 0 366 15 2 0. 04 BEPC 2. 2 240 20 1 0. 04 ATF 1. 3 138 1 20 0. 07 ALS 1. 9 197 . 5 320 0. 390 APS 7 1104 . 7 324 0. 099 2 new DR proposals in progress: - HERA – competing with XFEL - CESRTF – conversion starting in 2008; 1. 5 – 5. 5 Ge. V; e+ and e-; low emittance (3 nm); up to. 36 A(? ? ); competing with CHESS Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 11

Cross Section of HERA Magnet in Tevatron Tunnel Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 12

HERA Tunnel and Magnets Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 13

Possible Scheme for Positron Production and Acceleration § § § Conventional positron target Return beamline to front end of linac Two options for acceleration Ø Accelerate positron bunches between electron bunches spaced at 308 nsec Ø Use widely spaced bunches so that interleaved positrons/electrons is not an issue § § The point is to fill the positron ring for beam stability/emittance studies Two options for DR configuration Ø Reverse polarity of magnets and circulate positrons in same direction as electrons Ø Keep polarity the same and have duplicate feedback, collimators, masks, aborts, etc Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 14

This is a Work in Progress with Many Questions Unanswered § Could any of these facilities be (or evolve to) “the final thing”? § Should any of these facilities by deep underground? Differences in ground motion, temperature/humidity control, etc? § Can (an upgraded) photoinjector satisfy emittance, intensity, and pulse train length requirements for linac and DR tests? § cost? timeline? § Can competing facilities do better? (CESRTF and HERA DR) § Can any of these facilities have “dual use” -- ie, besides ILC beam physics/technology? § ……… Some Proposals for ILC Beam Test Facilities at FNAL Mike Church, 4/19/06 15