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Study of Position Sensitive E-E for Space Particle Telescope Pre-results of Geant4 simulation. 张云龙,王文骁,李翠. Motivation. Study of space science is in need of information of space particle(nuclide/ion). Important parameters: energy spectrum of particle and particle flux .
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Study of Position Sensitive E-E for Space Particle TelescopePre-results of Geant4 simulation 张云龙,王文骁,李翠
Motivation • Study of space science is in need of information of space particle(nuclide/ion). • Important parameters: energy spectrum of particle and particle flux. • First of all, identify particles. (Reconstruct Z and M in simulation.)
Particle identification • Due to ionization , particle will deposit energy in detector, and detector can output signal. • The value of output signal in detector relevant to the incident particle’s charge, kinetic energy and so on. • With measured detector’s signal, the particle’s charge and mass could be identified. Energy loss of incident particle could be described by Bethe-Bloch formula. Bethe-Bloch formula:
Telescope model z Elements’ thickness: First: 50m Second: 192m Third: 248m BGO: 63mm63mm40mm 90 80 Silicon detector 60 0.0 BGO y x
H1H2H3 /gps/source/clear /gps/source/add 1 /gps/particle ion /gps/ion 1 3 1 0 /gps/pos/type Point /gps/pos/centre 0. 0. 9.1 cm /gps/ang/type iso /gps/ang/mintheta 0.00 deg /gps/ang/maxtheta 15.00 deg /gps/ene/type Lin /gps/ene/min 0. MeV /gps/ene/max 200. MeV /gps/ene/gradient 0. /gps/ene/intercept 1. /run/beamOn 20000 /gps/source/clear /gps/source/add 1 /gps/particle ion /gps/ion 1 2 1 0 /gps/pos/type Point /gps/pos/centre 0. 0. 9.1 cm /gps/ang/type iso /gps/ang/mintheta 0.00 deg /gps/ang/maxtheta 15.00 deg /gps/ene/type Lin /gps/ene/min 0. MeV /gps/ene/max 200. MeV /gps/ene/gradient 0. /gps/ene/intercept 1. /run/beamOn 20000 • /gps/source/clear • /gps/source/add 1 • /gps/particle proton • /gps/pos/type Point • /gps/pos/centre 0. 0. 9.1 cm • /gps/ang/type iso • /gps/ang/mintheta 0.00 deg • /gps/ang/maxtheta 15.00 deg • /gps/ene/type Lin • /gps/ene/min 0. MeV • /gps/ene/max 200. MeV • /gps/ene/gradient 0. • /gps/ene/intercept 1. • /run/beamOn 20000
He3He4 /gps/source/clear /gps/source/add 1 /gps/particle ion /gps/ion 2 3 2 0 /gps/pos/type Point /gps/pos/centre 0. 0. 9.1 cm /gps/ang/type iso /gps/ang/mintheta 0.00 deg /gps/ang/maxtheta 15.00 deg /gps/ene/type Lin /gps/ene/min 0. MeV /gps/ene/max 400. MeV /gps/ene/gradient 0. /gps/ene/intercept 1. /run/beamOn 20000 • /gps/source/clear • /gps/source/add 1 • /gps/particle alpha • #/gps/ion 2 4 2 0 • /gps/pos/type Point • /gps/pos/centre 0. 0. 9.1 cm • /gps/ang/type iso • /gps/ang/mintheta 0.00 deg • /gps/ang/maxtheta 15.00 deg • /gps/ene/type Lin • /gps/ene/min 0. MeV • /gps/ene/max 400. MeV • /gps/ene/gradient 0. • /gps/ene/intercept 1. • /run/beamOn 20000
Li6Li7 /gps/source/clear /gps/source/add 1 /gps/particle ion /gps/ion 3 7 3 0 /gps/pos/type Point /gps/pos/centre 0. 0. 9.1 cm /gps/ang/type iso /gps/ang/mintheta 0.00 deg /gps/ang/maxtheta 0.01 deg /gps/ene/type Lin /gps/ene/min 0. MeV /gps/ene/max 500. MeV /gps/ene/gradient 0. /gps/ene/intercept 1. /run/beamOn 10000 • /gps/source/clear • /gps/source/add 1 • /gps/particle ion • /gps/ion 3 6 3 0 • /gps/pos/type Point • /gps/pos/centre 0. 0. 9.1 cm • /gps/ang/type iso • /gps/ang/mintheta 0.00 deg • /gps/ang/maxtheta 0.01 deg • /gps/ene/type Lin • /gps/ene/min 0. MeV • /gps/ene/max 400. MeV • /gps/ene/gradient 0. • /gps/ene/intercept 1. • /run/beamOn 10000
Reconstruct Z NUCLEAR INSTRUMENTS AND METHODS 145(1977) 583-591 The final calculated particle identification value “PI” , approximately (AZ2)1/3
PI calculation T1: thickness of E detector E1: E E2: total energy
Reconstruct Z H2 H3 Li7 Be Li6 H1 He3 He4 B C
Reconstruct M NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH A 424(1999)414-424 • Once the charge (Z) has been identified, the mass M of the specific isotope can be reconstructed by means of the equation: • A precise evaluation of such parameters a and b for each atomic species has been obtained by a fit of the following expression: R: the measured range E: kinetic energy a: is a constant of the medium b: [1.5, 1.8]
Measured range VS Kinetic energy proton alpha Be Li
mass He3 H1 H2 He4 H3
mass Be7 Be9 Li6 Li7 Be10 C12 C13 C14 B10 B11