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Published byRalf Phillips Modified over 8 years ago
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development of the neutron counters for the Spin dipole resonance Kazuhiro Ishikawa
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Our group experiment test experiment for the newly developed the neutron counters to measure the spin dipole resonance (SDR reaction). Simulation for the neutron counters by the Geant4 My research thesis
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フローチャート n 検出 ↑ d *singlet → p-n ↑ ( d, d* singlet ) ( d, d* singlet )↑ ( 、 ) (spin dipole resonance) ( 、 ) (spin dipole resonance)↑ Super nova (cooling mechanism)
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The condition of Supernova's explosion and the cooling velocity of neutron star is determined by the neutrino. The condition of Supernova's explosion and the cooling velocity of neutron star is determined by the neutrino. Mainly μ-neutrino and τ-neutrino is emitted by these reaction Mainly μ-neutrino and τ-neutrino is emitted by these reaction If we detect their neutrino, we can get the important information of Supernova. If we detect their neutrino, we can get the important information of Supernova. μ- neutrino and the τ- neutrino. SDR is used to detect the μ- neutrino and the τ- neutrino.
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We observe μ-neutrino τ-through by using the spin dipole resonance (SDR) reaction. We measure γ- decay on the 16O. SDR research is not made progress so much. We must firstly establish the probe SDR excited. We substitute the deuteron for the neutrino,d(, )d* singlet.
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What is the SDR reaction? Next state is J+=0-or 1- or 2-. SDR reaction change ΔS =1 and ΔL =1 and ΔT =1 compared initial state. Excited 16O* decay into 15N or 15O emitting γ- ray. (particle threshold 15N=10.2Mev,15O=7.3Mev)
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How to select the d + → d*singlet + (d*singlet is ). state exhausts 85% of the cross section under 0.5Mev in the p-n relative energy.
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To obtain the SDR cross-section (d*singlet,p-n) →Energy spectrum of relative energy E → select of
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Example in the (d,pn)
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The purpose of simulating a new neutron counter. resolution to be reached resolution to be reached angular resolution energy resolution angular resolution energy resolution We need almost the same performance neutron counter as the proton detector. We simulate the neutron counter by using geant4. proton detector resolution at the smart Optimization of detector dimensions to detect 1S0 state.
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Definition of geometry sincilator definition bc408 density 1.032g/cm refraction rate 1.58 H/C 1.104 Total volume(6 planes×5 layers ) 60cm×15cm×60cm
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Included in the scintilator Interaction definition Interaction definition γ photoelectric effect, compton scattering pair production pair production multiple scattering, ionisation loss multiple scattering, ionisation loss bremsstrahlungannihilat ion bremsstrahlungannihilat ion p elastic scattering,inelastic scattering ionisation loss,multiple scattering ionisation loss,multiple scattering n elastic scattering, inelastic scattering neutron capture neutron capture d,α, ion elastic scattering, ionisation, multiple - scattering scattering
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Result of simulation Energy loss Energy loss ↓ 135MeV neutron beam
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time information time information Resolution(0.4ns) is caused by thickness of scintilator. ↓ 135MeV neutron beam
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efficiency efficiency
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energy calculated from TOF Resolution is 0.4MeV
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The 7Li(p,n)7Be test experiment obtain the efficiency in the new neutron counter. obtain the energy resolution on the target. Beam source is.
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Experiment institution RARF
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smart First focal plane(F1) Second focal Plane(F2) Magnetic elements QQD QQDQD First order resolving power 4000 12000 Mean orbit radius 2.4 m 2.4 m Maximum magnetic field 1.5 T 1.5 T Typical Angular resolution 5-25 mrad 3 mrad
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Experimental result 7Li(p,n)7be Resolution is 2.6MeV.
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efficiency
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To develop the excellent neutron counter We must multiple sincilator to increase efficiency. We must remove more the γ-ray and th e particle ….d,p etc. We must improve the beam quality.
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