MICE Beamline PID w Aerogel Counters Ghislain Gregoire, Don Summers, Lucien Cremaldi*, MICE Collaboration Meeting, FNAL, Jun 06

ISIS Beam Line A B C

Array is offset from x,y = 0,0. Beam Spot at z = 20.763.4m 4x4 Aerogel Array Provides ample coverage. ~95% containment in 3x3. Array is offset from x,y = 0,0. Triangle tiles can reduce cost. Variation of Beam Spot size over counter length is minimal. Triangle tiles

Matsushita Electric Works 1.030+-0.001

Matsushita Aerogel Samples n=1.03 n=1.07(1.08) n=1.12 115 x 115 x 10.5 mm3 115 x 115 x 11.5 mm3

T = A exp{ -t C/l4} Rayleigh-like Transmittance T = A exp{ -t C/l4} Rayleigh-like C =0.041 1.03 n A C 1.03 98.99 0.041 1.08 98.84 0.252 1.12 96.96 0.638 t(nm) sample thickness (nm) wavelength 0.252 1.07 0.638 1.12 Blue photons are scattered w dN/dq = 1+cos2. Absorption minimal.

Performance (1) Run Configuration of good Mu/Pi (T.Roberts) Muons Peaking at 220 MeV/c Pion show high energy tail (p>350 MeV/c removed by tracking??) 16200 280

Muon Detection Efficiency The efficiency drop at low momenta is due to the proximity of the muon threshold in n=1.12 aerogel The efficiency at low momenta could be improved by increasing the thickness of the radiator

Momentum distributions of triggers Remember: the pion sample is exaggerated by a factor 40 Misidentified pions in the range 285 to 320 MeV/c Unambiguous separation of muons and pions (32 pions / 385 muons) There is no need for a momentum cut i.e. an actual pion impurity in this configuration only

Purity Matrix(4) Purity (4) Purity = Percent of good muons for a particular Trigger Configuration. P = Muon Purity >99% P = Pion Misid < 1.2 x 10-4

Design (1)

Aerogel Counter Design

Dimensions (3)

Radiator (2) Collection Mirror Radiator

Fermilab Test Beam July ‘06 Beam 200 GeV  Aerogel 1.03, 1.07, 1.12 PE yield vs incident angle Sr90 Measurements aerogel 200 GeV  mirror Rotating Table

Summer ‘06  = 1 @ FNAL 1x1x1 module white reflector Measure pe yields Pricing/Road Map Price (2 det) -64 Aerogel x $350USD ~ $20K -Reflectors $5K -Steele Boxes $5K -Table $5K -Installation and checkout $5K -Shipping $5K -(8-10) PMTs HARP - -Parts Fabricated in UM shop. -Mechanical Drawings UL. Summer ‘06  = 1 @ FNAL 1x1x1 module white reflector Measure pe yields Spring ‘07 Assembly Fall- 06 Mechanical fabrication Reflectors/Cones Aerogel purchase Summer ‘07 ready

Milestone Progress Report

Conclusion Aerogel Technology well suited to tag  in MICE beamline. Photoelectron yield adequate for high efficiency and low misid rate. Mechanical design highly advanced. Fabrication staightforward. Ready to install in MICE in summer ‘07. TRD Update & Saftey Sheets completed (Ghislain).

Muon Detection Efficiency (5)

Performance (3) n=1.12 muon n=1.12 pion n=1.07 muon n=1.07 pion

Performance (2) n Npe/cm L-cm e Npe(b=1) 1.07 11.4 2.3 0.6 16 1.07 11.4 2.3 0.6 16 1.12 18.3 2.3 0.6 25