UK Neutrino Factory Conceptual Design Stephen Brooks, Christopher Prior ASTeC Intense Beams Group, RAL s.j.brooks@rl.ac.uk Physics Motivation The discovery of neutrino masses requires the standard model of physics to be modified. Measuring their mass precisely is one of the few ways a new theory can be constrained. The mass differences between neutrino flavours cause oscillation from one type to another with a wavelength proportional to D(Mass2)*(Baseline)/(Energy), meaning baselines in the >1000km range are needed for the best detectable >10GeV neutrinos. Staging Scenario (UK Case) The neutrino factory complex could be built up in stages: upgrades to the ISIS proton synchrotron at RAL could supply both the neutrino factory and enhanced flux for existing neutron and muon science. The neutrino factory could itself be upgraded to a multi-TeV muon collider, which would have high-energy particle physics capabilities surpassing the LHC and ILC in several areas. This diagram shows the main subsystems of the neutrino factory. Four areas are highlighted in which the UK will perform key technology demonstrations within the next five years. 180MeV H− Linac Proton Driver Front End Proton Driver Required energy 5-15GeV Repetition rate 50Hz Mean power 4-5MW 3-6 bunches formed Compressed to 1-3ns RMS  Peak power 8-60TW 972MHz Side-Coupled Linac (SCL) to 180MeV 324MHz Drift Tube Linac (DTL) to 90MeV Beam Chopper RFQ to 3MeV LEBT at 35keV H− Ion Source Achromat for removing beam halo Proton Driver Front-End Test Stand (FETS) Two Stacked Proton Synchrotrons (full energy) 6GeV 78m mean radius Each operating at 25Hz, alternating for 50Hz total See also: FETS poster A prototype of the first stages in a high power proton driver is being constructed at RAL. Muon Ionisation Cooling Experiment (MICE) This project will construct a fully-engineered cooling cell with diagnostics and test its performance using muons extracted from the ISIS beam. Stripping Foil (H− to H+/protons) Two Stacked Proton Synchrotrons (boosters) 1.2GeV 39m mean radius Both operating at 50Hz Present 2010s 2020s 2030s Proton Power 150kW 1MW  2.5MW  5MW Neutron Science ISIS ISIS MW Upgrades ESS-class Machine Neutrino Physics Neutrino Factory Fundamental & Higgs Physics Muon Collider Solenoidal Decay Channel (in which pions decay to muons) Muon Cooling Dogbone Solid Target R&D Programme Pictured above is a test being conducted at RAL of the durability of wire samples of target materials under thermal shocks comparable to those in the real NF target, which are induced by an intense pulsed current. See also: MICE poster RF Phase Rotator Residual proton Beam Dump Tungsten target enclosed in 20T solenoid (produces pions from protons) Plan view of the new accelerators superimposed on the RAL and Harwell site. FFAG Electron Model of Muon Acceleration (EMMA) Dogbone Recirculating Linac (RLA) 5½ pass, 2-13GeV A new type of accelerator called a non-scaling FFAG is used in the final muon acceleration stages. The prototype EMMA is scheduled for construction at Daresbury. See also: EMMA poster Muon Decay Ring (muons decay to neutrinos) Solenoidal Muon Linac 0.2-2GeV Near Detector R110 R109 Far Detector 1 Far Detector 2 Neutrino Factory FFAG 2 25-45GeV FFAG 1 13-25GeV To Far Detector 1 To Far Detector 2 ~300m below ground