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ポータブル核物質NDA測定装置の開発計画Development of Portable Non-Destructive Assay System for SNMs
H. Ohgaki, Kyoto University
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Safety checking After detection of objects with strong suspicions of containing NMs at airports / harbors / Stations / Big Events, and at the time of taking out of NMs from containersTo check whether or not the objects contain explosives or toxic materials before opening.
Checking of NM(At the same time as safety checking in non-destructive manner) It is desirable to check the followings.
-fissile contents-U/Pu isotopic compositions
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Checking of Detected Objects
Several active interrogation systems for deployment in seaports and airports have been proposed.
Our team’s activity(R&D FY2012 – 2016)Supported by JST / MEXT
Successful reduced-scale demoDetect 1kg HEU hidden in 20ft containerInspection time: 3 min (400 containers per day)False alarm rate: <10 % 3 pulsed DD-IECs of 1e8 n/sec
R & D in NDA for SNMs
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Developed measurement method for active interrogation system
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Method Principle Neutron Source
NRTA Neutron Resonance Transmission Analysis
Measure the Energy distribution of transmitted neutrons
Pulse Neutron Source + TOF (large facility)
DGA Delayed Gamma-ray analysis
Measure the delayed Gamma-rays from nuclear fission.
Pulse Neutron Source
DDA Differential Die-Away analysis
Measure the SecondaryNeutrons from Nuclear Fission
(DT) Pulse Neutron Source
TENA Threshold Energy Neutron Analysis
Measure the Neutronswhich has higher energy than the DD neutrons
DD Neutron Source (compact => portable!)
①good SN ratio②Tritium free③CW machine : compact
DD neutron generator fast neutron detector
A significant portion of fission neutrons is above DD neutron energy.Detect secondary neutrons above the threshold energy.Scattering makes the probing neutron energy lower. Unless SNMs present, no neutrons above the threshold.
Use of DD is the key. Neither DT nor RI neutron source is applicable.No need of pulsing the neutron generator.0 1 2 3 4 5
neutron energy, E [MeV]
4
3
2
1
0
dn/d
E[a
.u.]
DD fusion(probe)
29%71%
2.45MeV
Threshold Energy Neutron Analysis (TENA)
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114 cm
146
cm
D中性子源CCDカメラ
非蒸発型ゲッタポンプ
四重極質量分析計
ガンマ線検出器LiF Pb
114 cm
146
cm
D中性子源CCDカメラ
非蒸発型ゲッタポンプ
四重極質量分析計
ガンマ線検出器LiF Pb
NEG pomp
CCD camera
RGA
D neutron source
γ-ray detector
1”diam.
5”di
am.
1”di
am.
3”diam.
5”diam.
NaI(Tl)
BGO PMT
1”diam.
5”di
am.
1”di
am.
3”diam.
5”diam.
NaI(Tl)
BGO PMT
Compact DD-IEC neutron source and discharge photo inside
BGO / NaI(Tl) combined γ-ray detector for directionality through anti-
coincidence technique
Landmine detector prototypeby use of a DD-IEC neutron source
and directional γ-ray detectors Schematic view of landmine detection via PGA of explosive (nitrogen)
R&D of Explosive Detection (Anti-personnel Landmine, 2002-2007)
Soil moisture 2 % Soil moisture 10 % Soil moisture 18.5 %
Experiments by use of Landmine Simulants (Wax-diluted TNT & RDX)
TNT : 240g & 100g
RDX: 100g & 29g
Soil moisture :2 , 10, 18.5 wt%
Buried depth: 5, 10, 15 cm
Measurement time: 10 min
Measured γ-ray Spectrum Example (100g RDX, BGO/NaI(Tl) )
0 2 4 6 8 10 12 1410-2
10-1
100
101
102
103
104
10.6 10.8 11.0 11.2 11.4 11.6 11.8 12.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
RDX100g Background
Cou
nts
[arb
.uni
t]
Energy [MeV]
H-2.22 MeV
N-10.83 MeVFe-7.63 MeV
10.70 10.75 10.80 10.85 10.90 10.95 11.0010.7 11.0
BG
RDX 100g
ROI for N-10.83 MeV to avoid influence of Si – 10.6 MeV
energy calibration by use of H – 2.22 MeVFe – 7.63 MeV
Location Detection Systems Property Checking Systems
1. Airports/Harbors
Illicit NMs in cargo containers
- Setting type (Large size)- Reliable (perfect) detection
of NMs
- Setting type (Large size)- Reliable (perfect) checking
of NMs
2. Any Locations(Checkpoints)
Illicit NMs in freights
- Portable type (Small size)- Reliable detection of NMs
- Portable type (Small size)- Reliable checking of NMs
(2015JFY-2019JFY)NRF-NDA Demonstration of
NMs in Heavy Shielding
(2015JFY-2017JFY)Development of Active Neutron NDA Techniques
with a D-T Neutron Source
Development of Basic Technology for Portable NM Detection/Property Checking
System using a D-D Neutron Source(budget to be requested)
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Development of Basic Technologies for Detection / Property Checking of NMs in Japan
東京オリンピックまであと 1633日 と7時間 51分 02秒
2016.02.03 12:09
Expected 10M visitors
Olympics: Tokyo to Beef Up 2020 Security After Paris Attacks Japan's Olympics Minister Toshiaki Endo on Monday promised to public safety the "top priority" of the 2020 Tokyo Games following deadly Paris terror attacks.
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Requirement of Immediate Industrialization
Target : Prototype 2018, Deploy until 2020 Conventional technology
Neutron generator:
DD Glow-discharge IEC
Neutron detector: Commercial Product
Tensioned Metastable Fluid Detector (TMFD)
NEDO12
Identification method to distinguish fission neutrons from probing neutrons.
Threshold Energy Neutron Analysis (TENA) Ref) K. Masuda et al., US-J IEC workshop (2012).Ref) Y. Takahashi et al., Proc. Nuclear Physics and Gamma-ray Sources for Nuclear Security and Nonproliferation, 341 (2014).
Neutron generator: portable and intense, DD mandatory.DD Glow-discharge IEC
Cf) Compact, transportable DD IEC developed ten years ago at KU for LM-detection.
Neutron detector: blind to probing DD neutrons and background gamma-rays, sensitive to neutrons above 2.45 MeV.
Tensioned Metastable Fluid Detector (TMFD)Ref) R.P. Taleyarkhan et al., Nuclear Engineering and Design 238, 1820 (2008).
What are crucially needed for successful “portable” system?
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Oil insulated HV junction
HV power supplyDC 120kV, 24kW
Weight < 30 kgNPR > 5 x 107 n/sec (DD)
cooling water24 kW, 50L/min
<70
cm
NEG pumpD2 gas supply & pressure control
Spherical IEC chamber
Portable DD-IEC
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Nano-Second Multiplicity EventTiming with CTMFD & Neutron Directionality
Bubble Formation and Growth
Linear Energy
Transfern(E)
n (E’)
ion (E-E’)
Centrifugal TMFD
100% blindness to X/gamma-rays. Blind to neutrons below a threshold energy. The threshold energy is variable. High detection efficiency above the threshold. Directionality (by A-TMFD).
Tensioned Metastable Fluid Detector (TMFD)
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SummaryOur team has been developing the active interrogation system
of SNMs. Starting R&D of the portable NDA for SNMs, especially
targeting to Tokyo Olympic 2020 supported by the JPN government (NEDO / METI).
Key technologies are: TENA analysis, TMFD neutron detector,and portable DD-IEC.
Next step : Explosive detection and development of TMFD,Superior performance
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