ISISNF03

ISIS as a Proton Driver for a Neutrino Factory : 

ISIS as a Proton Driver for a Neutrino Factory Christopher R. Prior CCLRC Rutherford Appleton Laboratory and Trinity College Oxford

Outline: 

Outline Possible bunch compression experiment on existing ISIS accelerator 1 MW upgrade as a spallation neutron source and a NF test bed for ns bunch compression, pion target experiments and studies of a pion/muon capture channel 5 MW upgrade as a combined neutron source and proton driver for a neutrino factory

ISIS: a 200-300 A Neutron Source: 

ISIS: a 200-300 A Neutron Source 70.4 MeV linac feeding an 800 MeV rapid cycling synchrotron operating at 50 Hz Installation of a Radio-Frequency Quadrupole and a combined h=2/h=4 RF system should upgrade machine to ~300 A, 240kW

Bunch Compression Experiment: 

Bunch Compression Experiment Bunch at extraction ~100 ns for spallation By changing the RF volts during the cycle, try to compress to ~5-10 ns rms Requires controlled beam loss at earlier times since not all particles can be compressed.

Slide6: 

Number of protons per bunch = 4.7 1012 Beam loss = 62.6% Rms p/p = 1.8 10-3 Bunch length = 18 ns Rms bunch length = 2.5 ns Beam loss during cycle ISIS: Volts comparison

3 Phase ISIS MW Upgrades: 

3 Phase ISIS MW Upgrades Phase I: new synchrotron 3 GeV top energy at 50 Hz for neutrons 8 GeV at 16.7 Hz as NF test facility Phase II: new injector ISIS decommissioned New 180 MeV linac and two stacked 1.2 GeV booster synchrotrons at 50 Hz Phase III: second main synchrotron at 25 Hz giving 2.5+2.5 MW at 50 Hz At 3.5 GeV for spallation neutrons At 6 GeV for NF proton driver

Phase I: New Synchrotron: 

Phase I: New Synchrotron 78 m mean radius (3 times ISIS) Tunes Qh=11.7, Qv=7.2 Short central dipoles help limit field to B~1.44 T at 8 GeV Magnet gradients < 9.8 T/m 184 m 107 m

Dynamic Aperture: 

Dynamic Aperture Chromaticity correcting sextupoles give dynamic aperture ~ 600  mm.mrad (normalised)

Acceleration Cycle: 

Acceleration Cycle B-field chosen to minimise RF voltages B(t)=B0-B1cos(2ft)+B2sin(4ft), B2=1/4√2

Longitudinal Simulation: 

Longitudinal Simulation Bucket to bucket transfer Bunch accelerated from 0.8 GeV to 3 GeV (50 Hz) Peak voltage 570 kV Simulation with TRACK1D Final bunch 72 ns

Phase II: A New 1.2 GeV Injector: 

Phase II: A New 1.2 GeV Injector Decomission the existing ISIS Build a new 180 MeV linac Construct two new 1.2 GeV booster synchrotrons, 39m mean radius 180 achromat, dispersion painting for loss-free ring injection.

ISIS2 – a 5 MW Proton Driver: 

ISIS2 – a 5 MW Proton Driver 3 bunches each of 1.7 1013 protons at 50 Hz 180 MeV H linac 180 achromat 6 bunches in each of two main synchrotrons at 25 Hz 3 GeV Spallation Neutron Source 6 GeV, 1 ns bunch compression for a Neutrino Factory

Status: 

Status Funding bids have been prepared and submitted to UK and EC organisations (HIPPI under the FP6 programme). Work is about to commence on a prototype beam chopper, in parallel with ion source, RFQ and DTL development. Detailed synchrotron studies continue as part of the UK Neutrino Factory Project.