VIII-Ⅱ-1. Project Research
Project 12PR12Development on Neutron Imaging Application

Y. Kawabata
Research Reactor Institute, Kyoto University
OBJECTIVES AND ALLOTED RESEARCH SUBJECTS :The aim of this project research is the development
on neutron imaging and its application.
ARS-1 Development on neutron imaging application in
KUR
ARS-2 Visualization of liquid-metal two-phase flow byusing neutron radiography
ARS-3 Visualization of two-phase flow in a polymer
electrolyte fuel cell
ARS-4 Neutron radiography on tubular flow reactor for
supercritical hydrothermal synthesis of nanoparticles
ARS-5 Quantitative Evaluation of void wave propagationin oscillatory flow by using neutron radiography
ARS-6 Appropriate soil thickness for neutron imaging ofwater movement to facilitate phytoremediation study
ARS-7 Neutron imaging of industrial components andsimulation using VCAD system
ARS-8 Continuous measurement of water in cement
during hardening
ARS-9 Three dimensional high-resolution neutron computed tomography at Kyoto University Research Reactor(KUR)
MAIN RESULTS AND THE CONTENTS OF THISREPORT :M.Kanematu et. al (ARS-1) studied the physicalprocess of the spalling phenomenom when the exposureof concrete structures to unexpected high temperature,such as during fire accidents. They applied neutron radiography to detect the hydraulic behavior under risinghigh temperatures to understand the spalling phenomenonof high strength concrete, focusing on the differences
between the normal concrete and polymer fiber concrete.
Y.Saito et al. (ARS-2) have developed an imaging
system to obtain dynamic information on such multiphaseflows in a metallic duct by neutron radiography. It has abetter efficiency to visualize liquid-metal two-phase flow
at a high frame rate (>100fps). Experiments were performed at the B-4 supermirror neutron guide facility of
the Kyoto University Research Reactor (KUR).
N.Takenaka et al. (ARS-3) visualized the water flow

採択課題番号 23P12（京大・原子炉）川端祐司

in a polymer electrolyte fuel cell. Fuel gas (hydrogen gas)and oxidant gas (air) are supplied to a polymer electrolyte
fuel cell (PEFC). Protons pass through the proton exchange membrane (PEM), and combine with oxygen toform water in the cathode reaction site. As water management in the PEFC is important, and water distributions during the operation have been measured.
T.Tsukada et al. (ARS-4) conducted the in-situ neutron
radiography of mixing behavior in the reactor and at theprocess conditions, which were used practically to synthesize metal-oxide nanoparticles. A variety of metal-oxide nanoparticles have been synthesized by supercritical hydrothermal synthesis. It is important to acquire
the correct knowledge about the mixing behavior of cold
aqueous feed solution and supercritical water in a hydrothermal reactor for the design and optimization of theprocess. Therefore, they used neutron radiography tovisualize the flow in a tubular flow reactor for supercritical hydrothermal synthesis, and investigated the effects of
fluid flow rates and temperature of supercritical water on
the mixing behavior in the reactor
N.Umekawa et al. (ARS-5) conducted the Critical Heat Flux (CHF) experiment under oscillatory flow
conditions, and the void fraction was measured simultaneously by using the neutron radiography. In designingboiling systems, CHF is a very important factor. Whenflow instabilities, such as density wave oscillation occur
under certain operating conditions, CHF is drasticallydecreased with an increase of oscillatory amplitude andoscillatory period. In order to clarify this phenomenon,
the void wave propagation was studied.
U.Matsushima et al. (ARS-6) measured the appropriate thickness of saturated gray lowland soil that isbasic data for investigating water movement in the soil byneutron imaging. It is important to investigate the pathways of heavy metals, such as cadmium, from soil toplants in order to study phytoremediation.
Y.Yamagata et al. (ARS-7) have constructed acooled CCD based neutron imaging device at E-2 radiography port and tested the performance using various
industrial components. Besides, captured images areprocess by VCAD software, which is developed at
RIKEN. VCAD system can handle three dimensional
data of "real" object, which usually contains profile errors
or defects inside. By using VCAD software, three dimensional images are reconstructed based on neutron radiography data.
T.Numao et.al (ARS-8) did not submit theirreport.
H.Kagawa et al. (ARS-9) have been working to refine
neutron radiography, where the use of high accuracy
X-rays mainly due to CT enables improved visibility. In
this case, they decided to perform image acquisition CT,
to consider the applicability of equipment, space components and parts inspection.

中性子イメージングの高度利用

プロジェクトPR12-1

Experimetal Research on the Hydraulic Behavior of High Strength Concrete
under High Temperature

M. Kanematsu, G. Emura1, M. Tamura2, N.Tuchiya2,
Y. Saito3 and Y. Kawabata3
Faculty of Science and Technology, Tokyo University of
Science1
Graduate School of Technology, Tokyo University of
Science2
Graduate School of Engineering, Tokyo University
3
Research Reactor Institute, Kyoto University

INTRODUCTION: The exposure of concrete structures to unexpected high temperature, such as during fire
accidents, may lead to spalling, fracture of the heatedsurface. Because this phenomenon is more critical in highstrength concrete, a small amount of polymer fiber isused as a countermeasure to prevent the formation of thefractural stresses.
The physical process of the spalling phenomenon isassumed to be due to the gas pressure build-up inside theporous media, restrained thermal interaction close to theheated surface or the simultaneous action of both[1].
However the mechanism of this phenomenon has notbeen fully elucidated yet, because it is difficult to measure the moisture behavior that is thought to be a key parameter to explain the explosive pressure formation.
In the present research, we applied neutron radiography to detect the hydraulic behavior under rising hightemperatures to understand the spalling phenomenon ofhigh strength concrete, focusing on the differences between the normal concrete and polymer fiber concrete.

movement in fiber concrete is comparatively high, whichmeans the PP fiber in concrete melts at the high temperature (at about 165°C) and forms relief paths which prevent the formation of evaporative pressure of moisture.
REFERENCES:[1] F.J.Ulm, O. Coussy, Z.P. Bazant, J. Eng. Mech. 125(3)(1999)272-282.

Fig. 1. Experimental setup of the heating element
Spalling partsa) Subtracted intensity of the ordinal concreteb) Subtracted intensity of the PP fiber concrete

EXPERIMENTS:
The 100x100x200 mm3 prisms
were sawn from a concrete block with a water cement
ratio of 18% and polypropylene(PP) fiber volume ratio of
0.1%. After demolding at 24 hours, the prisms were submerged in water at 20±2°C for 28 days and then cured at
atmospheric conditions of 20℃ and 40%RH. The initialwater contents of the concrete samples were controlled
by oven-dry under 105°C for two days.
The neutron radiography facility in the B-4 beam holeof KUR was used. A neutron radiograph was obtained
every 15 seconds during the heating experiment under
5MW operation. A Liquefied Petroleum(LP) gas burner
was used to raise the surface temperature to 1000°C in 30
seconds and was held at 1000°C for the remainder ofexperiment. To prevent direct heating from the lateralside, the sample was sealed with heat-resistant bricks andfixed in an aluminum cell as shown in Fig.1.
RESULTS: As shown in Fig. 2, the moment of spallation of ordinary concrete can be clearly observed by theneutron radiography, and the hydraulic behavior under
the fire condition can be examined by the intensity analysis of the images. The result shows that the hydraulicc) above:PP fiber concrete, below:ordinary
concrete
Fig. 2 The hydraulic behavior of concrete

採択課題番号 23P12-1 KUR における中性子イメージング適用分野拡大に関する研究 プロジェクト（京大・原子炉）川端祐司、斉藤泰司、（東京理科大学・理工）兼松 学、榎村 剛（東大・工）田村正道、土屋直子

PR12-2 Visualization of Liquid-Metal Two-Phase Flow by Using Neutron Radiography
Y. Saito and Y. Kawabata
Research Reactor Institute, Kyoto University
INTRODUCTION: Neutron radiography is a powerfultool for fluid flow visualization as well as multiphaseflow research [1]. Multiphase flows in a metallic duct
have been visualized clearly by using neutron radiography (NR). However, it would be still difficult to obtain dynamic information on such multiphase flows by
NR, because of insufficient neutron flux from neutron
sources and poor efficiency of imaging devices. In thiswork, we are trying to develop an imaging system, which
has a better efficiency to visualize liquid-metal two-phaseflow at a high frame rate (>100fps). Experiments were
performed at the B-4 supermirror neutron guide facilityof the Kyoto University Research Reactor (KUR)[2].
EXPERIMENTS: Figure 1 shows the schematic of theimaging system tested at the B-4 experimental room.
The imaging system consists of a NR converter(6LiFZnS(Ag)), a dark box, a macro lens, an image intensifier, and a high-speed video camera (Motion Pro Y-4,
IDT Co. Ltd.). The imaging system has no optical mirror
to reduce the optical loss in the dark box and was inclined
45 degree against the beam direction.
The imaging system was applied for an air-water
two-phase flow in a small tube and a liquid-metal
two-phase flow in a metallic tube during a 5MW operation at the KUR. The neutron flux at the exit of the B4
suppermirror tube was about 5×107(n/cm2s).

RESULTS: As shown in Figs. 2 and 3, clear two-phaseflow behaviors in a small stainless tube were visualized
by using the imaging system developed in this study.
Figure 4 shows the liquid-metal two-phase flow. As
shown in these figures, it was confirmed that the newimaging system can visualized clearly multiphase flows
at the B4 facility of the KUR.

Fig.2 Air-water two-phase flows in small tubes (O.D.=2
and 4mm).

Fig.3 Air-water two-phase flow in small(O.D.=1mm) and the time-averaged image.

0ms

50ms

100ms

150ms

tube

積分画像

Fig.4 Liquid-metal two-phase flow in a stainless tube
(O.D.=30mm) and a time-averaged image.

Neutron beam45Imaging system

REFERENCES:[1] Y. Saito et al., Nucl. Instr. Meth. Phys. Res. A, 542(2005) 168-174.
[2] T. Akiyoshi et al., J. Nucl. Sci. Tech., 29 [10],(1992) 939 – 946.

Fig.1 NR imaging system.

採択課題番号 23P12-2
液体金属流れの可視化計測に関する研究（京大・原子炉）齊藤泰司、川端祐司

プロジェクトPR12-3

Visualization of Two-phase Flow in a Polymer Electrolyte Fuel Cell

N. Takenaka, H. Asano, K. Sugimoto, H. Murakawa,Y. Kawabata1 and Y. Saito1
2

9 parallel channels(19mm×1mm)

Graduate School of Engineering, Kobe University
Research Reactor Institute, Kyoto University

1

INTRODUCTION: Fuel gas (hydrogen gas) and oxidant gas (air) are supplied to a polymer electrolyte fuelcell (PEFC). Protons pass through the proton exchange
membrane (PEM), and combine with oxygen to form
water in the cathode reaction site. The generated watermust be supplied appropriately to the membrane for protons conduction. On the other hand, the generated water
may affect the fuel cell performances because of blocking
the oxygen from reaching the cathode reaction site.
Therefore, water management in the PEFC is important,
and water distributions during the operation have been
wide concern. Measurements of water behavior in a
PEFC were carried out by using neutron radiography.
EXPERIMENTS: Neutron radiography system at B-4
port in KUR was used for visualization. A Gadolinium
type neutron color image intensifier (UltimageTM n γ
type (Gd-Type2), Toshiba Corp.) with 4 inch view size
and a CCD camera (Alta U16, Apogee Inst.) with pixel
area of 4096 × 4096 and gray scale of 12 bit were used.
Pixel size was 6.8 μm/pixel. Exposure time was 10 seconds and the measurement interval was 10 s. The cell
was rotated 90° using a rotating table during the interval.
Hence, water distributions in the in-plane andthrough-plane directions were alternately obtained every
20 s. Fig.1 shows schematic of a PEFC. Geometry of thePEFC is horizontal 9-parallel gas channels with equal
width and depth of 1 mm. The L/D was set at 600 using a
vertical slit with width of 3 mm. Experimental conditions
were a current density of 210 mA/cm2, a hydrogenflow-rate of 28 cc/min (utilization of 10%), and an air
flow-rate of 66 cc/min (utilization of 10%).
RESULTS: Figure 2 shows water distributions in-plane
and through-plane directions at elapse times of around 8
min and 23 min. After the 23 min, power generation
stopped because of water plugging in the channel. Water
behavior during the PEFC operation, the accumulation
process from the gas diffusion layer (GDL) to the channels, and size of the water accumulation were confirmed
as follows. Water generated in the GDL at the cathodeand evacuation into the channels started around 5 min.
Water tended to accumulate at the edge of the channels,
and accumulated as water drops in the channels. The sizeof the water drops grew up to 1 mm which is the same
size as the channel width and height. When the water
drops grew up to the 1 mm, power generation stopped
because of blocking the air supply.

Front view(in-plane)

Side view(Through-plane)

PEM + GDLs
Fig.1. Schematic diagram of a PEFC.
PEM + GDLs Channels

In-plane(8 min)Through-plane(8 min 20sec)

In-planeThrough-plane(23 min 20 sec)
(23 min 40 sec)
Fig.2. Water distributions in a PEFC.

採択課題番号 23P12-3
中性子ラジオグラフィによる沸騰二相流の研究
プロジェクト
（神戸大・工）竹中信幸、浅野 等、杉本勝美、村川英樹（京大・原子炉）川端祐司、齊藤泰司

PR12-4

Neutron Radiography on Tubular Flow Reactor for Supercritical Hydrothermal Synthesis of Nanoparticles

T. Tsukada, K. Sugioka, J. Adachi, S. Takami 1,
T. Adschiri1, K. Sugimoto2, N. Takenaka2, Y. Saito3
and Y. Kawabata3
Dept. of Chemical Engineering, Tohoku University
1
IMRAM, Tohoku University2
Dept. of Mechanical Engineering, Kobe University
3
RRI, Kyoto University
INTRODUCTION: Recently, a variety of metal-oxide
nanoparticles have been synthesized by supercritical hydrothermal synthesis [1]. For the design and optimization of the process, it is important to acquire the correctknowledge about the mixing behavior of cold aqueous
feed solution and supercritical water in a hydrothermal
reactor. Therefore, we used neutron radiography tovisualize the flow in a tubular flow reactor for supercritical hydrothermal synthesis, and investigated the effects of
fluid flow rates and temperature of supercritical water on
the mixing behavior in the reactor [2]. In this work,in-situ neutron radiography of mixing behavior in thereactor and at the process conditions, which were usedpractically to synthesize metal-oxide nanoparticles, wereconducted.
EXPERIMENTS: The tubular flow reactor consists ofstainless steel 1/8-inch tubes and a tubing connector atwhich water at room temperature (cold water), corresponding to the feed aqueous solution, is mixed with supercritical water. In the experiment, pressure in the reactor was set to be 25 MPa, and the temperatures of supercritical water Tscf were 658 and 666 K. The flow rates
of supercritical water Qscf were 8 and 12 g/min, and therange of cold water Qrt was between 1 and 6 g/min. The
tubing connector in the reactor, i.e., the mixing part, wasirradiated by neutron beam at 5 MW power for flow visualization, where the attenuation coefficient of neutron

Fig.1. Distributions of averagewater density at mixing part in the
tubular flow reactor.

beam for supercritical water is lower than that for cold
water depending on their density. The density of water isapproximately 0.3 g/cm3 at 658 K, and approximately 1
g/cm3 at room temperature, respectively.
RESULTS: Fig. 1 shows the distributions of averagewater density at the mixing part in the flow type reactor,
where the distributions were obtained by applying theappropriate image-processing technique to the neutron
radiography [2]. It is found that the cold water, feedaqueous solution, flows down along the right side wall,and that the density-stratified layer of two fluids is generated in the feed line of cold water.
Fig. 2(a) shows the effect of Qrt on the distributions ofwater density along the vertical white line in Fig.1 for
Qscf = 8 g/min. From the figure, the water density increases after mixing with cold water, and the tendency
becomes more remarkable as Qrt increases. Fig. 2(b)shows the effect of Qrt on the distributions of water density along the horizontal white line in Fig.1 for Qscf = 8
g/min. The water density increases rapidly near the rightside wall. The high density region becomes thicker as Qrt
increases. These distributions of water density correspondto the temperature distributions in the reactor.
CONCLUSIONS: In this work, it was demonstrated
that the mixing behavior of aqueous feed solution andsupercritical water in a tubular flow reactor used practically to synthesize metal-oxide nanoparticles can be visualized by neutron radiography.
REFERENCES:[1] T. Mousavand et al., J. Mater. Sci., 41 (2006) 1445.
[2] S. Takami et al., J. Supercrit. Fluids, 63 (2012) 46.

Fig.2. Effect of Qrt on the vertical and horizontal distributions ofwater density in the reactor for Qscf = 8 g/min.

採択課題番号 23P12-4 中性子ラジオグラフィを利用した超臨界水反応場の in-situ 観察 プロジェクト（東北大院・工）塚田隆夫、杉岡健一、足立 潤、（東北大・多元研）高見誠一、阿尻雅文、（神戸大院・工）杉本勝美、竹中信幸、（京大・原子炉）齊藤泰司、川端祐司

PR12-5

Quantitative Evaluation of Void Wave Propagation in Oscillatory Flowby Using Neutron Radiography

S. Fujiyoshi, S. Nakamura, K. Sakakura, M. Ozawa,T. Ami, R. Matsumoto, H. Umekawa and Y. Saito1
Dept. Mech. Eng., Kansai University
1
Research Reactor Institute, Kyoto University
INTRODUCTION:
In designing boiling systems,
Critical Heat Flux (CHF) is a very important factor.
When flow instabilities, such as density wave oscillation
occur under certain operating conditions, CHF is drastically decreased with an increase of oscillatory amplitude
and oscillatory period [1]. In order to clarify this phenomenon, it is important to understand the void wave
propagation. In this investigation, the CHF experiment
was conducted under oscillatory flow conditions, and thevoid fraction was measured simultaneously by using theneutron radiography.
EXPERIMENTS: An experimental apparatus was avertical forced convective boiling system ofion-exchanged water. Test section was made of stainlesstube with I.D. 5.0 mm, O.D. 7.0 mm and 1000 mm inheated length. It was uniformly heated by Joule heatingof DC power. The boiling experiment was conductedunder arbitrary oscillatory flow condition by means ofmechanical flow oscillator. The experimental conditions
were as follows; the system pressures were 0.3, 0.47, and0.55 MPa, the averaged mass flux G0 was set to 300
kg/m2s, the oscillation period  was 4 s, and the ratio of
oscillation amplitudes G/G0 were 1.0 and 1.5.
As a neutron source, Kyoto University Research
Reactor (neutron flux was 5×107 n/(cm2s) at the port exit
under 5 MW operation) was used. In the visualization
procedure, the short exposure period (0.03 s ) images

Fig.1 Visualization image( = 4 s，G/G0 = 1.0，q = 124.8 kW/m2, xeq =0.009)

were taken synchronized with the flow oscillator. By integrating of these 34 same phase images, the image
which has the enough dynamic range was reconstructed.
In this way, the pseudo-time continuous data of void fraction could be obtained.
RESULTS: In Fig.1, the quantitative evaluation resultof the void fraction is shown with the orifice output
which corresponds to the inlet flow rate. As shown inthese figures, the void fraction fluctuation under oscillatory flow conditions can be clearly visualized by this image processing.
In Fig.2, the wall temperature, the void fraction, theinlet mass flux and the differential pressure across the test
section are drawn. In the figure, calculation results of theLumped-parameter model [1] are also drawn. These results include the very important information to estimate
the boiling two-phase flow phenomena under unstale
flow condition. The more detail discussion will be reported elsewhere.
REFERENCES:[1] M. Ozawa et al, Trans IChemE, 79 (2001) 389-401.

Fig.2 Comparison with the simulation results.
( = 4 s，G/G0 = 1.0，q = 124.8 kW/m2, xeq =0.009)

採択課題番号 23P12-5 強制流動沸騰系における管内液膜挙動の定量評価に関する研究 プロジェクト（関大）梅川 尚嗣、小澤 守、網 健行、廣瀬 拓哉、中村 祥太、阪倉 一成、藤吉 翔太、
松本 亮介、吉村 智也（京大・原子炉）川端 祐二、齊藤 泰司、沈 秀中PR12-6

Appropriate Soil Thickness for Neutron Imaging of Water Movement
to Facilitate Phytoremediation Study

U. Matsushima, R. Takamatsu1, K. Hirota2 and
Y. Kawabata3
Faculty of Agriculture, Iwate University
1
School of Veterinary Medicine, Kitasato University
2
RIKEN Innovation Center3
Research Reactor Institute, Kyoto University
INTRODUCTION: It is important to investigate thepathways of heavy metals, such as cadmium, from soil toplants in order to study phytoremediation. A possible
pathway of cadmium is via the plant intake of watercontaining dissolved cadmium. The mass flow of
cadmium due to plant intake was observed in rhizosphere[1]. Neutron imaging is a good tool for observing water
movement from soil to plant roots. However, the distancethat a neutron beam can penetrate moist soil is limited
because of the large cross section of hydrogen. The
present report aims to present the appropriate thickness of
saturated gray lowland soil that is basic datafor
investigating water movement in the soil by neutron
imaging.
EXPERIMENTS: Gray lowland soil, which is widelydistributed in alluvial lowlands, valley plains, and alluvial
fans, was employed as the soil sample. A quartz glass
container with a wedge-shaped cross section was filledwith water-saturated gray lowland soil (Fig. 1). Becauseof the wedge-shaped cross section, the irradiated sample
thickness varied continuously across the width of theobtained neutron image. The experiments were
performed using the neutron tomography instrument
setup in the E2 beam hole at KUR. The irradiation time
for capturing neutron image was 10 min.

the soil formed a single layer. Beyond 3 mm, two or more
were formed, and the number of layers depended on thefilling factor. The increase in attenuation from left toright in Fig. 1 resulted from an increase in the number ofsoil particle layers.

Fig. 2. Neutron image of gray lowland soil. Upper
scale: space between glass walls; lower scale:distance from the joint of walls.
The linear absorption coefficient changes with the densityof the irradiated material. However, the filling factor
should also be considered when discussing soil particles.
Irregularities in the filling factor of the soil particles
caused fluctuations in the apparent linear absorption
coefficient (Fig. 3). The apparent linear absorption
coefficient increased with the thickness. Removing the
kinetic restriction imposed by the walls resulted in proper
filling of the soil particles. Therefore, although neutron
penetration decreases with moist soil thickness, thisrelation only holds when the particles are filled properly.

Fig. 1. Schematic diagram of the sample container.
RESULTS: As shown in Fig. 2, soil particles weretrapped in the small space between the quartz glass walls.
The particles were ellipsoidal, and the average length ofthe major axis of the particles that could be individually
distinguished in the image was 2.0 mm, with a standard
deviation of 0.2 mm. Bcrecause of the varying
relationship between the particle size and the space
between the walls, the soil particles arranged themselves
into different numbers of layers aoss the width of thecontainer. Until about 3 mm from the apex of the wedge,

Fig. 3. Relationship between apparent linear
absorption coefficient and space between glass walls.
REFERENCE:[1] T. Hashimoto et al., Annu. Meet. Jpn. Soc. Sci.
Plant Nutr. (2011) Tsukuba.

採択課題番号 23P12-6
中性子ラジオグラフィの植物研究への応用
プロジェクト（岩大・農）松嶋卯月（北里大・獣医）高松利恵子（理研）広田克也（京大・原子炉）川端祐司

PR12-7

Neutron Imaging of Industrial Components and Simulation using VCAD System

Y.Yamagata*1*2, K.Hirota*1, S.Morita*2, J.Ju*2,
Y.Ohtake*1*3, H.Yokota*1, S. Wang*1, K. Shimazaki*2,
T.Sera*1*4, S. Satoh*5 , Y.Kawabata*6, Y. Saitoh*6,
M.Hino*6, M.Kitaguchi6, M.Sugiyama*6

sure to obtain sufficiently good image. Photos
shown in Fig.1 are processed and intensity andcontrast are adjusted, otherwise, the image of theobject is difficult to recognize.

RIKEN Innovation center*1,
RIKEN Advanced Science Institute*2,
RIKEN Nishina Accelerator Research Center*3,
Osaka University*4
KEK*5
Kyoto University Research Reactor Institute*6
INTRODUCTION:
Non-destructive testing of industrial components is becoming important for recent production engineering. The
purpose of such testing includes the quality
controlof the product to lower the production cost, to maintainreliability and safety, to realize ecological performance.
Neutron radiography has advantage over X-ray thatheavy metals like steel, nickel or tungsten can be wellpenetrated, while light elements like hydrogen gives better contrast so that liquid inside metal structure or composite materials can be observed with better precision.
The authors have constructed a cooled CCD based neutron imaging device at E-2 radiography port and tested
the performance using various industrial components.
Besides, captured images are process by VCAD software,
which is developed at RIKEN. VCAD system can handle
three dimensional data of "real" object, which usuallycontains profile errors or defects inside. By using VCAD
software, three dimensional images are reconstructedbased on neutron radiography data.
EXPERIMENTS:
A cooled CCD based neutron imaging device was constructed. It has 6LiF/ZnS based scintillator with thicknessof 100micrometer and area of 150x150mm. The cooled
CCD camera has 4008x2672 pixels. This resulted in theequivalent pixel size at scintillator of about 50 micrometer.
Fig. 1 shows images and intensity histograms
taken by cooled CCD camera. Although this istaken at 1MW operation, the intensity of direct
beam just beside the object is about 1600 with
2x2 binning mode at exposure of 10 seconds. With
1x1 binning mode, pixel intensity of 2500 was
obtained at exposure of 1min. This cooled CCD
has 16bit pixel depth, so maximum intensity is65535. Those results indicate that only 2 to 4 % offull intensity is obtained using this condition. It
may be necessary to give several minutes expo-

採択課題番号 23P12-7

2x2 binning(2004x1336) 10sec

1x1 binning 1min (4008x2672pixel)

Fig.1 Images by cooled CCD (KUR E-2port 1MW)
Image intensity and contrast adjusted

A number of industrial samples are captured by thiscamera and some images are processed to construct 3D
images. Fig. 2 shows the image of Li-ion battery used bya camera. The shape of right side battery is normal but
the shape of left side one is little bit expanded. The electrolyte of the battery can be well observed by neutron
radiography. Fig.3 shows neutron radiography

image of ice and water. The density difference
between ice and water can be observed. Imageintensity and contrast are adjusted in theseimages.

Fig.2 Li-ion batteries

Fig. 3 Ice and Water

中性子ラジオグラフィによる工業製品の内部情報取得と プロジェクト
ＶＣＡＤによるシミュレーション（理研）山形豊、広田克也、森田晋也、朱正明、大竹淑恵、横田秀夫、王 盛、島崎勝輔、（大阪大）世良俊博（KEK）佐藤節夫（京大・原子炉）川端祐司、杉山正明、齊藤泰司、
日野正裕、北口雅暁

PR12-8

Measurement of Water Content in Hardened Cement Paste
by Neutron Imaging

T. Numao, I. Funakawa, N. Teshima, Y. Kawabata1
Y. Saito1, K. Hirota2, S. Morita2 and Y. Yamagata2
Department of Engineering, Ibaraki University
1
Research Reactor Institute, Kyoto University
2
Advanced Science Center, RIKEN
INTRODUCTION: In this study, we investigated amethod to quantify the amount of free water content in
the hardened cement paste which was changed every
moment in the drying process using neutron radiography.
In addition, in the same environmental conditions, thewater loss was measured by gravimetry method (Electronic balance) and the drying shrinkage were measured
by differential transformer transducer to examine thevalidity of this method.
OUTLINE OF EXPERIMENT
Outline of neutron radiography examination:
Measurement of neutron radiography in this study was
carried out at E2 port in KUR. Table 1 shows the specifications of neutron radiography facility.
Experimental method: Figure 1 shows an Outline ofmeasurement system. Also, the experiment overview was
as shown in Table 2. In addition, the thin wall cylindrical specimen was in Fig. 2.
Experimental result and consideration: Water content of specimen(W/C=30%) obtained by neutron radiography were examine by comparing water loss in specimen measured with electronic balance.
The influence such as neutron scatterings was received in
the neutron radiography at 3cm in the distance of thespecimen and the converter. Therefore, the calculation
value by 10cm which is the distance by the influence is
not received is necessary. Therefore, mass attenuation
coefficient λw=3.0154(cm2/g) of water in 10cm which
had been obtained for previous research was used.
Variation for water content for each unit volume(=Bulk
density of water in paste（g/cm3）), Δρw is shown as Eq.(1)
w 

Pw

Table1. Specifications of the neutron radiography facility
3.2×105 (n/cm2･sec)
100
400
1.1×106(n/cm2・mR)
Fluorescent converter（6LiF/ZnS : Ag）
2048×2048pixel (16bit)
approximately 80~100μm/pixel
85mm
1
RIKEN system
30 seconds

Thermal Neutron Flux
L/D
Cadmium Ration/γ Ratio
Converter
pixel number
Resolution
Lens
Power (MW)Camera system
Expose time

Table2. Experiment overview
Specifications Water cement ratio (%)
of Thin-wall
Shape (mm)cylindrical
specimen
Cement type30, 40Height:100, Thickness:1,
Outer diameter:15
Ordinary Portland Cement
30%: 1, 40% :1
The distance between speciNeutron irradiation
The number
men and Converter:3cm
of specimen
Gravimetry of water loss 30% :1
Drying shrinkage
30% :2, 40%: 2Experiment environment ;temperature-humidity 25˚C, RH55%
Electronic balance:
Gravimetry of water loss

Inside E2 guideSpecime n

Desiccator
Flexible hoseSpecimen

NeutronAluminum chamber

Differential transformer
transducer：
Measurement o f drying
shrinkage

Temperature andhumidity Controller

Data logger
Personal computer

Fig.1.

Outline of measurement system.

(1)

ww
Where, ΔPw: Variation in attenuation factor (difference attime t=0 and time t=t), λw: Mass attenuation coefficient(cm2/g) and δw: Bulk thickness (Matrix thickness) (cm)

Left; Fig.2. Thin-wall cylindrical specimen.
Right; Fig.3. Comparison of aging variation of water loss weight for each unit
volume calculated from gravimetric method and neutron radiography.

ΔPw was calculated using this equation the result comesout as Fig.3. Water content calculated with Eq.(1) and thewater loss by the gravimetric method is the tendency tothe agreement was obtained.

It is thought that the neutron radiography method enables
the quantification of the water content in hardened cement paste.

採択課題番号 23P12-8 中性子イメージングを用いたセメント硬化体中の水分測定 プロジェクト（茨城大・工）沼尾達弥、舟川 勲、手島直之（京大・原子炉）川端祐司、齊藤泰司（理化学研究所）広田克也、森田晋也、山形 豊PR12-9 Three Dimensional High-Resolution Neutron Computed Tomography at Kyoto University

Research Reactor Institute (KUR)

H. Kagawa, T. Nagata, T. Masuoka, K. Kajiwara,
R. Hata1, K. Mochiki1, Y. Saito2 and Y. Kawabata2
Propulsion Group, Japan Aerospace Exploration Agency
Tokyo City University

Research Reactor Institute, Kyoto University
INTRODUCTION: Neutron radiography can reveal invisible objects using X-ray technology. However, the resolution of neutron radiography is generally low, therefore, it
is said that the neutron radiography is unsuitable for thedetailed inspection of industrial products. We have beenworking to refine neutron radiography, where the use ofhigh accuracy X-rays mainly due to CT enables improved
visibility. In this case, we decided to perform image acquisition CT, to consider the applicability of equipment, spacecomponents and parts inspection.
EXPERIMENTS: We constructed a high-resolution neutron CT system and carried out neutron experiments at theB4 port of KUR in the Kyoto University Research Reactor
Institute. Fig.1 shows an overview of the CT imaging system used on this experiment. The neutron imaging device
adopted was the Toshiba Ultimage™. This Toshiba color
neutron imaging device was used to convert the images
which were recorded by a digital SLR (EOS 5D Mark II)
using a commercially available product. The color Image
Intensifier(I.I.) is a Gd-type neutron color image intensifier
with an input sensitive area 4 inches in diameter. Tie digital
camera can be replaced by the ALTA U16 (4096 x 4096
pixels, CCD) from the original set of EOS 5D Mark II(5616 x 3744 pixels, CMOS). Using this system, precise
neutron transmission images with a gap of 12.5μm in the
ASTM-SI indicator could be recognized. The three dimensional neutron CT reconstruction image successfully
demonstrated its usefulness. However, the parallelism of
the B-4 neutron beam port is poor, hence a collimator wasadded between the port and I.I. to improve the neutron
beam parallel quality. If we use a pinhole collimator, theresolution will improve, but the noise of the imaging system will also increase, which will impair visibility.
Neutron defilade cover

II’s power unit

rial cannot be visualized by X-ray inspection. However,neutron radiography is possible to visualize the existenceof polymer material. In addition, the seal is covered withmore complex metal parts and observation itself is very
difficult. CT technology can be used to enhance the visibility of complex shapes observed. We can obtain CT images
with high resolution neutron radiography, and evaluate thepotential for observation by neutron radiography and CT ofcomplex-shaped propulsion system components. Neutron
radiography also visualizes the fluid inside the valve. The
differential signal between the image containing fluid andthe vacant image reveals a flood image. The images taken
are shown in Fig.2.

Fig.2. Solenoid valve neutron radiographies obtained at B4 port of
KUR. (a,b,c):EOS camera system, (d,e,f):ALTA camera system

RESULTS: The differential images were processed on the
CT process and shown in Fig. 2 and 3. Metallic parts werevisualized well, but for measurement of seal geometry,targeted in this experiment, the evaluation of the deformation was insufficient. This was due to poor neutron
beam quality, hence a higher quality neutron source is desired.

Color I.I.

Camera power unit

Collimator

Groundingwire

Neutronflux
XYZθ Stage

Image dataStage
controller

Elevator

Monitor
Trigger signal

Controller

Control signal

Fig.1. Overview of the high-resolution neutron CT system

A lot of phenomena, caused by contamination of the seal
points of the propulsion systems, significantly impact on
the satellite system. However, such contamination is too
small to be discovered by nondestructive external inspection, hence the need for high resolution inspection. The seal
is made of polymer material in most cases. Polymer mate-採択課題番号 23P12-9

Fig. 3. The fluid CT tomogram results of ALTAREFERENCES:[1] Kenichi KUSHIKI and Hideshi KAGAWA (JAXA),
B20 49th Conference on Aerospace Propulsion and Power,
2009[2] K.Kushiki, et al., On-Board Energetic Equipment, Avignon, 2004.
[3] T.Nagata, et al., 42nd AIAA/ASME/SAE/ASEE Joint
Propulsion Conference, 9 - 12 July, Sacramento, California,(2006), AIAA 2006-4876.

京大炉（KUR）を利用した人工衛星用触媒分解特性のプロジェクト
可視化技術に関する研究（京大・原子炉）川端祐司、斉藤泰司、関本 俊（JAXA）香河英史、長田泰一、升岡正、梶原堅一（都市大）畑亮介、持木幸一