Progress in Accumulator and Compressor Ring Studies

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Progress in Accumulator and Compressor Ring
Studies
H. Schönauer

• Transfer Lines SPL - Accumulator
• (Microbunch Stretching, Jitter Compression,
• Momentum Collimation, Space Constraints)
• Feasibility of lower Repetition Rate lt75 Hz
• at present ? 50 Hz
• H- Injection at 50 Hz
• Foil Heating

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Studies of the Proton Driver Rings

• The charted territory
• of the CERN NF
• SPL
• PDAC (Proton Driver
• Accumulator- Compressor
• in ISR tunnel)
• Extraction towards
• target station

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Proton Driver Accumulator - Compressor
Evolution of the 4 MW Scenario
0) Isochronous Rings 1) PDAC 1 High ?
Accumulator Compressor 2 GeV, 100 Hz, 12
bunches, H- Injection 600 turns 2) PDAC 2 2.2
GeV, 75 Hz, 140 bunches RF 44 Mhz, matched to
Muon Cooling Front End 3) PDAC 2 bis 50 Hz H-
Injection 820 turns (?)
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PDAC Layout in ISR Tunnel
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Layout of the transfer line
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• Transfer Lines presently under study
• SPL to Accumulator
• Drift Collimator Achromat
• Congestion problems in certain regions
• Searching alternatives to Collimator Achromat
• Bunch Stretching with Wiggler Modules

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Effect of SPL Jitter AFTER debuncher 230m
drift buncher (180ps bunch length, matched
beam)
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Momentum Collimator Achromat fitting in ex-ISR
Tunnel
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Momentum Collimator Achromat fitting in ex-ISR
Tunnel
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Wiggler Section for Microbunch Stretching
NF Note 069, Autin, Giovannozzi, Martini, Royer
Doubles the bunch stretching w.r.t. free
drift -gt 130 ps Provides Dispersion Bump
D20m -gt Replacement of Collimator Achromat in
the SPL to ISR tunnel ?
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Effect of Repetition Rate on the Accumulator
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ACCSIM Simulation of H- Injection in the 50Hz
Accumulator First 5 Turns injected
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ACCSIM Simulation of H- Injection in the 50 Hz
Accumulator 820 Turns (End)
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ACCSIM Simulation of H- Injection in the
Accumulator 100 Turns (Zoom)
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ACCSIM Simulation of H- Injection in the 50 Hz
Accumulator 820 Turns (End)
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ACCSIM Simulation of H- Injection 820 Turns
with refined space charge calculation
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ACCSIM Simulation of H- Injection Energy
Deposition in the Foil (750 ??g/cm2 C)
The average number of foil traversals depends
strongly on the foil margin 1 mm... 1 2.1
traversals 2 mm... 1 4.9 traversals
Energy deposit (MeV/mm2)
(82000 Superparticles)
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Alternative ScenarioCERN 4 MW 30 GeV / 8 Hz
Proton Driver
ISR Tunnel
180 MeV H- linac
Collimator Achromat
2.2 GeV / 50 Hz Booster R37.5m
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