Beam-Line Analysis m. apollonio 7/7/2010 CM27 - RAL 1

MC (G4Beamline) DATA M0 10-240 7/7/2010 CM27 - RAL

MC (G4Beamline) DATA M1 10-240 7/7/2010 CM27 - RAL

7/7/2010 CM27 - RAL

Characterizing the BL  MATRIX Intensive Program (started in June with CR as MoM) Choose Range of Momenta  initial optics: M0 scan of the DS triplets (and single Q4,..Q9) for some relevant optics define variation of Twiss Parameters as a function of optics MC simulation DATA Analysis Comparison Optimize M0  Mopt: awesome or awful? (*) 700mV ~ 20 mu-/spill 7/7/2010 CM27 - RAL 5

The BL can be thought as constituted by TWO blocks: US (=PIONS) and DS (=MUONS) BL momentum scale is a pair of values (P0 = momentum at target, PSol= momentum at Decay Solenoid exit, or D2) P0 defines the momentum scale for PIONS PSol defines the momentum scale for MUONS Momentum scale(s) must match the US Diffuser face values  initial optics: M0 easy, once defined Pdif we can work back Psol and P0 through the tables. However the Twiss parameters at Diffuser are “random” Recall also the main philosophy in defining (P0, Psol) select Psol such that BACKWARD GOING muons are captured so increase PURITY 7/7/2010 CM27 - RAL

m kinematic limits 350 MeV/c 195 MeV/c m @ the Dksol exit (G4Beamline) 6-240 m @ the Dksol exit (G4Beamline) 10-240 6-200 7/7/2010 CM27 - RAL

3,140 Pdif=151 a=0.2 b=0.56m t=0.0mm 3,200 Pdif=207 a=0.1 b=0.36m P(MeV/c) e 140 200 240 3 Ptgt=321.3/Psol=185 Pdif=151 a=0.2 b=0.56 m t=0.0 mm Ptgt=390/Psol=231 Pdif=207 a=0.1 b=0.36 m Ptgt=453.6/Psol=265 Pdif=245 b=0.42 m t=0.0mm 6 Ptgt=327.6/Psol=189 Pdif=148 a=0.3 b=1.13 m t=5.0 mm Ptgt=408.6/Psol=238 Pdif=215 b=0.78 m t=7.5 mm Ptgt=471.6/Psol=276 Pdif=256 b=0.8 m t=7.5mm 10 Ptgt=338.4/Psol=195 Pdif=164 a=0.6 b=1.98 m t=10 mm Ptgt=429.3/Psol=251 Pdif=229 a=0.4 b=1.31 m t=15.5 mm Ptgt=486/Psol=285 Pdif=267 b=1.29 m 3,140 Pdif=151 a=0.2 b=0.56m t=0.0mm 3,200 Pdif=207 a=0.1 b=0.36m t=0.0mm 3,240 Pdif=245 a=0.1 b=0.42m t=0.0mm 6,140 Pdif=148 a=0.3 b=1.13m t=5.0 6,200 Pdif=215 a=0.2 b=0.78m t=7.5mm 6,240 Pdif=256 a=0.2 b=0.8m t=7.5mm 10,140 Pdif=164 a=0.6 b=1.98m t=10mm 10,200 Pdif=229 a=0.4 b=1.31m t=15.5mm 10,240 Pdif=267 a=0.3 b=1.29m t=15.5mm 7/7/2010 CM27 - RAL

This pair is our goal: how do we get it? P (MeV/c) 3,140 3,200 3,240 finding the element (3,240) means to find the BL optics that matches the MICE optics for a beam of 3 mm rad at a P=240 MeV/c 6,140 6,200 6,240 eN (mm rad) the element (10,200) is the BL optics matching a MICE beam with 10 mm rad at P=200 MeV/c 10,140 10,200 10,240 This pair is our goal: how do we get it? 7/7/2010 CM27 - RAL 9 (*) 700mV ~ 20 mu-/spill

Hyp.: eN0 is known (~1 mm rad trace space) we proceed backward: fix P/eN in the cooling channel fix the optics in the cooling channel (a3,b3) solve the equations giving a,b and t at the US face of the diffuser (*) b0 a0 Diffuser b1 a1 b2 a2 b3 a3 t BL MICE e1 (*) MICE note 176 e0 7/7/2010 CM27 - RAL 10

m p So the question becomes: how do we “tell” the beamline to be a0, b0 at US_Diff? solution(s) we optimise the BL by varying Q4-Q9 let us break the BL in two parts: US and DS in what follows I mean a p m beamline DS part: choose Q4-Q9 shoot a beam check a,b at Diffuser vs “target” values repeat m Q4 Q1 Dipole1 DK solenoid Q2 Q3 Dipole2 Q5 Q6 Q7 Q8 Q9 p US part: we can optimise the MAX number of pions but not much magic left … 7/7/2010 CM27 - RAL 11

p  m beam line: typical m spectrum at the exit of the DS Rationale select p u.s. of DKSol with D1 select m d.s. of DKSol with D2 back scattered muons == purity 7/7/2010 CM27 - RAL

we already have an initial solution: the “central value” Key Point materials in the BL cause energy loss (also emi_growth) in order to have P_mice=200 MeV/c we need to define P_D2 properly then we define Ppi_tgt how? the best choice is dictated by beam purity 3,140 3,200 3,240 6,140 6,200 6,240 10,140 10,200 10,240 7/7/2010 CM27 - RAL

In the original scheme the pi  mu beamline is Ppi=444  Pmu=256 Best separation PI/MU p acceptance Will it work? Pdiff = 215 NB.: PD2=256 MeV/c becomes Pdif=215 MeV/c 7/7/2010 CM27 - RAL

i.o.t. accommodate several mu momenta another “shortcut” scheme was adopted (aug 2009): Define one lower Ppi ~ 350/360 and several different Pmu (we lose in purity …) p acceptance Pdiff = 148 215 256 Ppi (tgt) = 350 195 350 7/7/2010 CM27 - RAL

d.s. BL tuning: match to diffuser Q4 Q1 Dipole1 DK solenoid Q2 Q3 Dipole2 Q5 Q6 Q7 Q8 Q9 Pp=444 MeV/c Pm=255 MeV/c Pm=214 MeV/c Pm=208 MeV/c fix D1 fix D2 p 7/7/2010 CM27 - RAL 16

- a first round of the BL optimised (e,P) matrix has been produced in august 2009 (“shortcut”) however the few data taken in november reveal a pretty strange look one thing I dislike is using only one momentum for the pion (US) component and Select the backward going muons 7/7/2010 CM27 - RAL

http://mice.iit.edu/bl/MATRIX/index_mat.html 7/7/2010 CM27 - RAL

PI- (444MeV/c) MU- (256 MeV/c) at D2 PI- should be here: 30.44 0.943269 0.943269 ~29. RUN 1174-1177 – PI- (444MeV/c) MU- (256 MeV/c) at D2 PI- should be here: 30.44 NB: DTmu(256)= DTmu(300) * beta300/beta256 = 28.55 * .943/.923 = 29.13 7/7/2010 CM27 - RAL

? PI- should be here: 30.44 RUN 1201 – PI- (336.8MeV/c) MU- (256 MeV/c) at D2 MU- should be the same as before … what is that? 7/7/2010 CM27 - RAL

(arbitrary statistics) G4Beamline Generation up To DS Generate Gaussian Beam with defined COV-MAT (arbitrary statistics) COV-MAT x’ x y’ 7/7/2010 CM27 - RAL y

wrap-up … Consider all 9 cases: one Ppi + one Pmu per case (no “shortcuts”) Define initial BL currents (from scaling tables) Check tuning with G4Beamline use simulation output at DS to infer the COV-MAT of the beam Generate a Gauss-beam with that CovMat: E.g. MatLab tool, fast + any number of particles … Propagate / optimise this beam in the DS section By hand (GUI tool) By algorithm (GA) check results versus real data … 7/7/2010 CM27 - RAL

7/7/2010 CM27 - RAL