The first muon beam from a new high-intensity DC muon source, MuSIC Tran Hoai Nam, Department of Physics, Osaka University On behalf of the MuSIC collaboration PANIC11@MIT - July 26th, 2011 1
Outline Mo#va#on The MuSIC Key features Beam test & results Summary 2
Why intense muon beams? Future muon- related programs: neutrino factories muon colliders searches for clfv: COMET, Mu2e Need 10 11-10 14 muons/sec Highest intensity available: 10 8 muons/sec at Paul Scherrer InsJtute (PSI), Switzerland need 3-6 orders higher One idea of improvements: new pion capture systems 3
Principle of pion capture system 4
Principle of pion capture system PSI: 1.2 MW (590 MeV, 2 ma)* 10-7 muons/proton/gev * doi:10.1016/j.nuclphysa.2009.05.086 4
Principle of pion capture system PSI: 1.2 MW (590 MeV, 2 ma)* 10-7 muons/proton/gev MuSIC: 10-4 muons/proton/gev * doi:10.1016/j.nuclphysa.2009.05.086 4
Muon Science Innovative Channel Research Center for Nuclear Physics Osaka University 5
MuSIC at RCNP, Osaka University Research Center for Nuclear Physics (RCNP), Osaka University has a cyclotron of 400 MeV with 1 microa. The energy is above pion threshold. MuSIC West experimental hall The beam current would be upgraded to 5 microa in future. 6
Key features of MuSIC Pion capture system Transport solenoid Expected performance 7
Pion capture system GM cryocooler Proton beam Graphite target φ 40 mm t 200 mm 1 m 8
Transport solenoid Curved solenoid, R = 3 m, 180 deg. magnejc field at axis: 2 T superconducjng coils at every 6 deg. allow selecjng charge and momentum 9
Transport solenoid Curved solenoid, R = 3 m, 180 deg. magnejc field at axis: 2 T superconducjng coils at every 6 deg. allow selecjng charge and momentum 9
n Curved Solenoids Transport solenoid This drift can be compensated by an auxiliary dipole field parallel to Compensation Magnetic Field the drift direction given by Curved solenoid, R = 3 m, 180 deg. Charged Particle Trajectory 1 at axis: 2 T p 1magneJc field! " Charged Particle Trajectory Charged Particle Trajectory in Curved Solenoids Bcomp = cos θ + A center of helical trajectory of eg. superconducjng coils at every 6 dcharged particles in a curved Vertica Drift in a Curved Solenoid solenoidal field is drifted by A center of helical trajectory of p : Momentum of theselecjng particle charge and allow A center of helical trajectory of charged This drift particles can be compensated by in a curved q : Charge of theparticle particle Charged Trajectory in Curved Solenoids! field parallel"to Vertic momentum charged particles in a curved anaauxiliary dipole Drift in Curved Solenoid solenoidal field is driftedfield by 1 1 p r : Major radius of the solenoid Vertical Compensation Magnetic D =drift direction θbend given cos θ + rift in a Curved field Solenoid solenoidal is drifted by the by! : atan(p /P ) qb 2 cos θby" T L A center of helical trajectory of This drift can be compensated! p dipole! a curved "! 1 field parallel "1 to Bcomp charged particles in an auxiliary D : drift distance D = θ cos θ + Vertical Compensation 1 p 1 1 Magnetic Field p bend 1 qb 2 cos θ ft in a Curved Solenoid solenoidal field is drifted by the drift direction given by cos θ + D= θbend cos θ + comp = field BB : Solenoid qr 2 cos θ qb 2 cos θ! : Bending angle of the solenoid bend D : drift distance!! " " channel 1 p 1 1of the particle 1 p field D : drift distance pb: Momentum B : Solenoid sol of particle B p : Momentum = costhe θ+ D= θbend cos θ + B : Solenoid q!:comp Charge of the particle qr 2 cos θ qb field 2 cos θ : Bending angle of the solenoid channel bend q : Charge of the particle!bend : Bending angle of the solenoid channel!p: :atan(p T/PL) of the particle Momentum r : Major radius of the solenoid Dp :: drift distanceof the particle Momentum Momentum the particle qp :: Charge of theofparticle Bq::Solenoid field! : atan(pt/pl) Charge of the particle Charge ofl)the particle!q ::This atan(p T/P effect can be used for!bend : Bending angle of the solenoid channel B comp! : atan(pt/pl) r : charge Major radius of the solenoid and momentum p : Momentum of the particle! :selection. atan(p T/PL) can be used for q : Charge of2011 the particle Tuesday, July 26, 9 This effect qr 2 cos θ
Expected muon yield various experiments using collimators, DC separators, and so on. By=-0.04T By=+0.04T At the end of the transport solenoid (180 deg.) - At the end of transport solenoid (180 deg.) - MARS and G4beamline 10
Status Constructed, in operation 11
A photo of MuSIC 12
Beam test (June 19-21) Purpose: muon yield esjmajon by lifejme measurement: target: Cu, Mg counters: plasjc scinjllators Target HPGe Beam Plastic counters MPPC read out by muonic X- ray measurement: Neutron shielding Mg target HPGe detector Plastic counters Cu target Mg target Thickness 3.5 mm 6 mm 20 mm Area 380x50 mm 2 370x80 mm 2 370x80 mm 2 13
Beam test setup 40 cm 5 cm 14
Participants of the 2nd and 3rd Beam Test Objects Measure the number of muons / proton from muon life muonic X-ray Participants Osaka U. A. Sato, H. Sakamoto, Y. Kuno, S. Hikida, T. N. Hoai, N. M. Truong Osaka U. (Chemi) A. Shinohara, R. Kasamatsu, K. Fujiwara RCNP M. Fukuda KEK M. Yoshida, T. Adachi KURRI Y. Mori UCL, UK S. Cook, R. D Arcy U. of Saskatchewan, Canada C. Rangacharyulu 15
Time spectrum Free muon* Cu** Plastic scint.** 2197.03 ± 0.04 163.5 ± 1 2026.3 ± 1.5 *http://pdg.lbl.gov **DOI: 10.1103/PhysRevC.35.2212 16
Time spectrum ~2000 µ+/sec for 6 pa 3x10 8 µ+/sec for 1 µa (preliminary result) Free muon* Cu** Plastic scint.** 2197.03 ± 0.04 163.5 ± 1 2026.3 ± 1.5 *http://pdg.lbl.gov **DOI: 10.1103/PhysRevC.35.2212 16
Muonic X-ray Run 544 - Mg target - By = +0.04 T - 26 pa - 1h20min 17
Muonic X-ray Run 544 - Mg target - By = +0.04 T - 26 pa - 1h20min Preliminary result: 10 8 µ - /sec for 1 µa 17
Summary A new high- intensity muon beam line is under construc#on at Osaka University, and is expected to provide 10 8 muons/sec (both μ+ and μ- ). Pion capture solenoid and 36 deg. of transport solenoid have been built and successfully operated. Beam test preliminary results: we can achieve 10 8 muons/sec with 1 μa current. Future plan: opera#on at 1 μa current (in prepara#on) Your comments on design of beam line and beam quality are very welcomed. If you are interested in the MuSIC, please join us. 18
Thanks for your attention! 19
Backup 20
At 36 deg. Pi/Mu ratio 7000 μ + ParticleID Entries 4 Mean 53.31 RMS 120.1 6000 5000 4000 π + 3000 2000 1000 π - μ - 0-250 -200-150 -100-50 0 50 100 150 200 250 Particle ID 21
Simulation geometry 22
124 ±11 619 ± 25 Tuesday, July 26, 2011 23
Upstream Veto 24