Transcript development of neutron counter

development of the neutron
counters for the Spin dipole
resonance
Kazuhiro Ishikawa
Our group experiment
test experiment for the newly developed the neutron counters
to measure the spin dipole resonance (SDR reaction) .
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 τneutrino.
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 resonan
(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( 16 O ,
)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 γray. (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
energy.
under 0.5Mev in the p-n relative
To obtain the SDR cross-section
(d*singlet,p-n) →Energy spectrum of
relative energy E → select of
Example in the
(d,pn)
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
γ
p
n
d ,α, ion
Interaction definition
photoelectric effect, compton scattering
pair production
multiple scattering, ionisation ｌｏｓｓ
ｂｒｅｍｓｓｔｒａｈｌｕｎｇａｎｎｉｈｉｌａｔｉｏｎ
elastic scattering ,inelastic scattering
ionisation loss ,multiple scattering
elastic scattering, inelastic scattering
neutron capture
elastic scattering, ionisation, multiple scattering
Result of simulation
Energy loss
↓ 135MeV neutron beam
time information
↓ 135MeV neutron beam
Resolution(0.4ns) is caused by thickness of scintilator.
efficiency
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
.
Experiment institution
ＲＡＲＦ
smart
Magnetic elements
First order resolving power
Mean orbit radius
Maximum magnetic field
Typical Angular resolution
First focal plane(F1) Second focal Plane(F2)
QQD
QQDQD
4000
12000
2.4 m
2.4 m
1.5 T
1.5 T
5-25 mrad
3 mrad
Experimental result
7Li(p,n)7be
Resolution is 2.6MeV.
efficiency
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.