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development of the neutron counters for the Spin dipole resonance. Kazuhiro Ishikawa. test experiment for the newly developed the neutron counters to measure the spin dipole resonance (SDR reaction). Our group experiment. My research thesis.
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development of the neutron counters for the Spin dipole resonance Kazuhiro Ishikawa
test experiment for the newly developed the neutron counters to measure the spin dipole resonance(SDR reaction) . Our group experiment My research thesis Simulation for the neutron counters by the Geant4
フローチャート n検出 ↑ d *singlet → p-n ↑ ( d, d* singlet ) ↑ ( 、 ) (spin dipole resonance) ↑ Super nova (cooling mechanism)
SDR is used to detect the μ- neutrino and the τ- 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 If we detect their neutrino, we can get the important information of Supernova .
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 .
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)
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.
To obtain the SDR cross-section (d*singlet,p-n) →Energy spectrum of relative energy E →select of
The purpose of simulating a new neutron counter. Optimization of detector dimensions to detect 1S0 state. resolution to be reached angular resolution energy resolution proton detector resolution at the smart We need almost the same performance neutron counter as the proton detector. We simulate the neutron counter by using geant4 .
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
Included in the scintilator Interaction definition γ photoelectric effect, compton scattering pair production multiple scattering, ionisation loss bremsstrahlungannihilation p elastic scattering ,inelastic scattering ionisation loss ,multiple scattering n elastic scattering, inelastic scattering neutron capture d ,α, ion elastic scattering, ionisation, multiple - scattering
Result of simulation ↓135MeV neutron beam Energy loss
time information ↓135MeV neutron beam Resolution(0.4ns) is caused by thickness of scintilator.
energy calculated from TOF Resolution is 0.4MeV
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 .
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
Experimental result 7Li(p,n)7be Resolution is 2.6MeV.
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.