MICE Demonstration of Ionization Cooling Update JB. Lagrange, J. Pasternak � on behalf of the MICE collaboration 1
Outline Demo lattice � Optimization � Results � Summary and future plans JB Lagrange - MAP meeting - June 2015 2
Outline Demo lattice � Optimization � Results � Summary and future plans JB Lagrange - MAP meeting - June 2015 3
Demo Lattice 4 JB Lagrange - MAP meeting - June 2015
Radiation shutter and movable secondary LiH absorber. Vacuum chamber Rails LiH � Lead shutter Secondary � absorber 5 JB Lagrange - MAP meeting - June 2015
Coil currents (6 mm, 200 MeV) Coil Demo lattice Nominal values (step V) Upstream E2 +253.00 255.46 Upstream C +274.00 288.27 Upstream E1 +234.00 239.37 Upstream M2 +203.13 290.69 Upstream M1 +240.61 274.34 Upstream AFC1 +77.86 245.65 Downstream AFC1 +77.86 245.65 Upstream AFC2 -72.94 245.65 Downstream AFC2 -72.94 245.65 Downstream M1 -218.39 274.34 Downstream M2 -187.68 290.69 Downstream E1 -234.00 239.37 Downstream C -274.00 288.27 Downstream E2 -253.00 255.46 6 JB Lagrange - MAP meeting - June 2015
Demo Lattice Magnetic field Bz [T] absorber AFC AFC z [m] 7 JB Lagrange - MAP meeting - June 2015
Initial beam Pure muon beam, ~10 000 particles � Position: before first plane upstream tracker (after diffuser) � Gaussian distribution � Normalised rms longitudinal emittance = 20 mm � Normalised rms transverse emittance = 6 mm Cuts PID cut � Transmission cut � Radial cut r < 200 mm, at first and last plane. 8 JB Lagrange - MAP meeting - June 2015
Old reference lattice Transverse beta AFC absorber AFC Beta [mm] z [m] 9 JB Lagrange - MAP meeting - June 2015
Old reference lattice 4D emittance 4D Emit. [mm] absorber AFC AFC 5.5% � cooling z [m] 10 JB Lagrange - MAP meeting - June 2015
Old reference lattice 6D emittance 6D Emittance absorber AFC AFC z [m] 11 JB Lagrange - MAP meeting - June 2015
Outline Demo lattice � Optimization � Results � Summary and future plans JB Lagrange - MAP meeting - June 2015 12
Optimization Optimization through 2 parameters � � phase advance of the channel � � Strength of the focusing elements 13 JB Lagrange - MAP meeting - June 2015
Phase advance Phase advance is computed from the last plane of the upstream tracker to the first plane of the downstream tracker. � Different phase advances for different lattices show the same effect: phase advance should stay between half-integer resonances. 630 deg. (1.75 × 360 deg.) seems to be the optimum: � � Best momentum acceptance, � � smallest non-linear effects (chromatic mismatch downstream minimized). 14 JB Lagrange - MAP meeting - June 2015
Focusing strength Once the phase advance and values of beta at the absorbers is decided, only free parameters are � the length between SS and Cavity module, � the length between the AFCs. � � Different cases show that M1 should be minimized to limit non-linearities. so the length SS-Cavity should be kept minimum (case of the reference lattice) � � Different cases show that large values of beta in the FC trigger strong non-linearities. � �� � ➯ Optimum of the length AFC-AFC. 15 JB Lagrange - MAP meeting - June 2015
AFC - AFC Length Different lengths have been tested � L 0 (old reference lattice) � L 1 (L 0 - 376.5 mm) � L 2 (L 0 - 187.0 mm) � L 3 (L 0 - 93.5 mm) � L 4 (L 0 - 46.7 mm) � � Best performances for length L 0 & L 4 . � �� � ➯ L 4 seems to be the best lattice. � �� � 16 JB Lagrange - MAP meeting - June 2015
Outline Demo lattice � Optimization � Results � Summary and future plans JB Lagrange - MAP meeting - June 2015 17
Coil currents (6 mm, 200 MeV) Coil Optimized lattice Old reference lattice Upstream E2 +253.00 +253.00 Upstream C +274.00 +274.00 Upstream E1 +234.00 +234.00 Upstream M2 +158.81 +203.13 Upstream M1 +239.68 +240.61 Upstream AFC1 +76.39 +77.86 Downstream AFC1 +76.39 � +77.86 Upstream AFC2 -71.95 -72.94 Downstream AFC2 -71.95 -72.94 Downstream M1 -218.45 -218.39 Downstream M2 -152.20 -187.68 Downstream E1 -234.00 -234.00 Downstream C -274.00 -274.00 Downstream E2 -253.00 -253.00 18 JB Lagrange - MAP meeting - June 2015
Optimized Lattice Magnetic field Bz [T] absorber AFC AFC z [m] 19 JB Lagrange - MAP meeting - June 2015
Optimized lattice Transverse beta AFC absorber AFC Beta [mm] z [m] 20 JB Lagrange - MAP meeting - June 2015
Optimized lattice 4D emittance absorber AFC AFC 4D Emit. [mm] 5.6% � cooling z [m] 21 JB Lagrange - MAP meeting - June 2015
Optimized lattice 6D emittance absorber AFC AFC 6D Emittance z [m] 22 JB Lagrange - MAP meeting - June 2015
Outline Demo lattice � Optimization � Results � Summary and future plans JB Lagrange - MAP meeting - June 2015 23
Summary Optical parameters have been studied and optimization of the length have been done. � Best performance for length L 4 (5.6% 4D cooling). 24 JB Lagrange - MAP meeting - June 2015
Future plans Update of the geometry with latest information from step IV. � Study of different emittances for � 140 MeV/c, � 200 MeV/c, � 240 MeV/c. � Paper including all settings to be finalized soon. 25 JB Lagrange - MAP meeting - June 2015
Thank you for your attention 26 JB Lagrange - MAP meeting - May 2015
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