MICE Beam Line Design Oct 24 th 2005 Dean Adams, Kevin Tilley Based on TURTLE element definitions by K Walaron, T Roberts and K Tilley

Beam Requirements into Mice Spectrometer P (MeV/c)  ε RMS  mmrad ● To match into spectrometer α=0,  =2p/qB ( α,  are optical twiss parameters) ● Hence for case in study. Line delivers : x RMS = y RMS = 3.25 cm x’ RMS = y’ RMS = 97.6 mmrad ● RMS Acceptance of Mice Experiment  ε = 10  mm rad. dp/p=10%. Hence x,y < 4.2 cm x’,y’ < 125 mmrad. Case under Study

Mice Beam line Piece of Beam line under Review

Muon Beam Line Optic. TOF separation 6.11 m Sigma envelopes Final Distributions Collimator Quad app cm. Collimator Happ 8 cm All Muon Beam p Dp/p=10% Beam collimation for TOFs TOF,CK1 Rates < 3.2 MHz

TOF0 distributions Un-collimated, Rate ~2.6 MHz 8 cm collimation Rate ~2.1MHz

TOF0 distributions Un-collimated, Rate ~2.6 MHz 8 cm collimation Rate ~ 2.1MHz x rms = 3.5 cm y rms =5.6 cm

CK1 Distributions, Rate ~ 2.1 MHz (All Beam) x rms = 3.9 cm y rms = 5.3 cm

TOF1 Distributions, Rate ~ 1.21 MHz (All Beam) x rms = 3.75 cm y rms = 3.43 cm

Upstream of lead scatterer, Rate ~ 1.21 MHz (All Beam) Achieved :x rms = 4.47 cm y rms = 3.25 cm x’ rms =30 mrad y’ rms = 48 mrad  ε x rms ~ 2.5  mm rad,  ε y rms ~ 2.8  mm rad Need 6.0  mmrad, increase angular divergence using lead scatterer.

Downsteam of 7.6 mm lead scatterer, (dp/p=10%+Acceptance Cut, Rate drop 1.21 to 0.67 MHz) Wanted :x RMS = 3.25 cm y RMS = 3.25 cm x’ RMS =97.6 mmrad y’ RMS = 97.6 mmrad Achieved :x RMS = 3.48 cm y RMS = 2.85 cm x’ RMS =90.7 mmrad y’ RMS = 101 mmrad  ε xrms ~ 5.97  mm rad,  ε yrms ~ 5.45  mm rad

SEPT04 version, Downsteam of 7.6 mm lead scatterer. No Detector Scatter (dp/p=10%, Rate = 0.61 MHz) Wanted :x RMS = 3.25 cm y RMS = 3.25 cm x’ RMS =97.6 mmrad y’ RMS = 97.6 mmrad Achieved :x RMS = 4.31 cm y RMS = 4.82 cm x’ RMS =90.4 mmrad y’ RMS = 84.5 mmrad

Whats next ? Run this lattice through G4beamline to check lattice design tools. –Done. Reasonable Match into Mice Spectrometer, Turtle Beam smaller emittance (TJR,CR) –Differences due to G4beamline modelling of quad apps, fringe field effects and multi particle scattering. –Turtle/G4 Rates at TOF0 2.1, 2.5 MHz and at TOF1 1.2, 1.2 MHz, x2 good muons wrt Sept04 (TJR/CR) –Hence TURTLE good for prototyping designs. Have G4Beamline extrapolate to p=140,240 MeV/c cases and determine effects of detector scattering. – Done in Turtle (KT) Small effect Check the beam sizes at detectors are acceptable. Re-tune lattice to meet x,y rms half widths of 3.25 cm. If above OK, study the remaining parameter space (p,ε) with this lattice.