CO12-1

Terahertz Absorption Spectra of Cholic Acid and its Sodium Salt

M. Kawase and T. Takahashi1
Nagahama Institute of Bio-science and Technology
Research Reactor Institute, Kyoto University

1

INTRODUCTION: Various applications of terahertz(THz) electromagnetic waves have been reported inmany fields, such as medical diagnosis, pharmaceuticalanalysis, and security enhancement. Absorption spectrain the THz range are very sensitive to differences in the
crystal structure [1], and are applied to study the polymorphs of medicines [2]. THz spectra are also sensitive
to the states of assembled molecules. In this study, we
examined the characteristics and usefulness of coherent
THz wave, and applied it to the analysis of bile acids,
which are popular components of natural medicines.
EXPERIMENTS: Coherent THz wave was obtained
from the transition radiation generated by L-band linear
accelerator in Kyoto University Research Reactor Institute. The absorption spectra were measured as
time-domain signal by the composite type liquid-helium-cooled silicon bolometers after through Martin-Puplett type interferometer and sample. By Fouriertransforming the time-domain signal, the amplitude
spectra were obtained [3]. Cholic acid and its sodium salt
were used as samples.
RESULTS: Both powder and pellet forms of samples
were used in this measurement. The size of pellets ofboth samples was 1 mm thickness containing 0.37 mmolof compound. A sample holder of 1 mm thickness wasused in the measurement of powder sample. The spectraof cholic acid and its sodium salt (sodium cholate) are
shown in Figs. 1 (A) and (B), respectively. In the pellet
form, a possibility was found that cholic acid has a weakabsorption band near 6 cm-1. Moreover, the pellet form
showed a better transmission than a powder form in theregion from 11 to 24 cm-1. One of the reasons of thisphenomenon is considered as follows. In the process of
forming a pellet, cholic acid powder was pressed. By thepressure, a change of assembly in the self-organizedstructure of cholic acid might have happened. It is plausible that this change of assembly was observed as thechange of spectrum.

On the other hand, no significant difference between
the spectra of the two forms of sodium cholate was observed. Because sodium cholate did not form theself-organized form, assembly of molecules was notmuch influenced by pressure in forming pellet, and no
significant difference was observed in spectra.
By comparison between the spectra of cholic acid andsodium cholate, the weak absorption was observed inboth pellet and powder form of sodium cholate at low
wave number from 2 to 15 cm-1. It should be clarified
in future study where this weak absorption in low wave
number comes from. These results were supported by
XRD and THz time domain spectroscopy [4] (data notshown).

A

B

Fig. 1 Coherent THz spectra of cholic acid (A) and its sodium salt (B)Solid line is spectrum of powder form sample, and dashed line is that of pellet form.

By using two kinds of THz wave sources, we canshow a possibility of a change of assembly in the
self-organized structure of cholic acid by pressure. The
detail of the mechanism should be investigated by moremeasurement of THz spectrum, XRD and so on.

REFERENCES:[1] Y. S. Lee, “Principles of Terahertz Science and Tech
nologyy” Springer, 2009.
[2] P. F. Taday, I. V. Bradley, D. D. Arnone, and M. Pepper,.J. Pharm. Sci., 92, 831-838, 2003.
[3] T. Takahashi, T. Matsuyama, K. Kobayashi, and Y.
Fujita, Rev. Sci. Instrum., 69, 3770-3775, 1998.
[4] M. Yamaguchi, F. Miyamaru, K. Yamamoto, M. Tani,
and M. Hangyo, Appl. Phys. Lett., 86, 053903,2005.

採択課題番号 24001 テラヘルツ分光法による医薬品および医薬品原料の評価系の確立（長浜バイオ）川瀬雅也（京大・原子炉）高橋俊晴

共同通常

CO12-2

A Brain Radiation Necrosis Model in Laboratory Animals

T. Miyata, T. Thoho, E. Yoritsune, M. Furuse, T. Kuroiwa,
S. Masunaga1, H. Tanaka1, N. Kondoh1, A. Maruhashi1, K.
Ono1and S. Miyatake
Department of Neurosurgery, Osaka Medical College
Research Reactor Institute, Kyoto University

1

INTRODUCTION: Since medical treatment apparatus
progressed in recent years, the high dose radiotherapy tothe brain tumor becomes possible, and, as a result, theprognosis of the brain tumor has improved. On the other
hand, the brain radiation necrosis which arises during thelong-term observation period after intensive radiotherapy
becomes a serious problem. Although a part of molecularmechanism in a brain radiation necrosis was shown by
our previous research, in order to prove these hypotheses
strictly, it is necessary to create a brain radiation necrosis
model in laboratory animals, and to analyze the pathology for each stage. Understanding the regulation mechanism of the cytokine in the brain radiation necrosis may
have an important role in the treatment development.

×10

EXPERIMENTS: Three 28-wk-old female Fisher rats
with body weight 220 ± 5 grams were irradiated of 35
Gy to the right hemibrain with a single collimated (10mm × 10 mm) 60Co gamma-ray irradiator underanesthesia. Gamma-ray irradiation was applied
using a 60Co gamma-ray irradiator in the KUR.
The irradiation method referred to the report of Wang etal., Li et al., and Nordal et al [1, 2, 3].

RESULTS: From 2011 to 2012, 47 rats were irradiated at
KUR, which we had reported that there were no apparent
histopathological abnormalities, at that time. But only
one rat in the 35 Gy cohort was found to have abnormal
signs of gait and movement from 26 weeks post-radiation.
No gross neurologic abnormalities were observed in otherrats. Standardized H&E staining was used to detect morphologic characteristics of brain tissue between 20 and 28
weeks after irradiation. There was apparent histopathological abnormalities in the brain, including white matterand blood vessel changes after all dose, as shown in
Fig.1.
Newly irradiated 3 rats in the 35 Gy cohort had no apparent changes.

Fig. 1.
H&E staining in the specimen of the 35 Gy irradiatedbrain 28 weeks after irradiation. There were brain necrosis, micro bleeding, and interstitial edema. (Original
magnifications, ×10, ×200)
REFERENCES:[1] S. Wang et al., Cancer Res 69 (2009) 1190-1198.
[2] Y. Li et al., Cancer Res 61 (2001)3348-3354.
[3] RA. Nordal et al., Clin Cancer Res 10 (2004)
3342-3353.

採択課題番号 24028
放射線壊死の病態解明と新規治療法の研究
共同通常（大阪医科大学・脳）古瀬元雅、頼經英倫那、宮田とも、東保太一郎、宮武伸一、黒岩敏彦（京大・原子炉）小野公二、増永慎一郎、田中浩基、近藤夏子

CO12-3

Radiation-Induced Luminescence for Applying to Retrospective Dosimetry

H. Fujita, M. Sakamoto1 and T. Saito1
Nuclear Fuel Cycle Engineering Laboratories, JAEA
Research Reactor Institute, Kyoto University

1

INTRODUCTION: It is well known that quartz exposed to ionizing radiation emits afterglow (AG), radioluminescence (RL), thermoluminescence (TL) and optically stimulated luminescence (OSL). The luminescencephenomena have been used for retrospective dosimetry(e.g. [1, 2]). However, the reason for the emission mechanisms of their luminescences except for BTL [3] fromJapanese natural quartz has not yet been well explained.
In this study, the emission mechanisms of UVTL, RTL
and OSL were investigated in conjunction with various
radiation-induced phenomena after annealing treatmentsof quartz samples, involving TL, OSL and electron spinresonance (ESR) measurements. In addition to the luminescence mechanism investigation, as-received surface
soils were irradiated by gamma-ray of 60Co source whichwere collected at various places in Ibaraki prefecture. The
irradiated samples were used in pulsed OSL (P-OSL)
dosimetry test. The P-OSL can selectively extract OSL
signals of quartz from various kinds of OSL signals
emitted by minerals [4].
EXPERIMENTS: Coarse quartz grains (150~250 m)
were extracted by a general treatment of 6M hydrochloric
acid (HCl) and 6M sodium hydroxide (NaOH) followedby concentrated hydrofluoric acid (HF) and sieving
treatments. Further purification of the quartz grains was
performed by hand selection for the sake of eliminationof feldspar grains as low as possible under a microscope.
The quartz samples were annealed at 500 and 800 ºC in
an electric furnace. The annealed quartz samples were
irradiated with 60Co source at room temperature at Kyoto
University Research Reactor Institute (KURRI). The irradiated samples were stored at room temperature for one
day to eliminate afterglow effect in dark room. The ESR
measurement was carried out using an ESR spectrometer(Jeol Ltd., JES-TE 200) at room temperature and −196 ºC,
respectively. Prior to the ESR measurements, the quartz
samples were annealed for 1 min at 50 ºC intervals ranging from 150 to 300 ºC as preheat treatment. After the
ESR measurements, all luminescence measurements were
performed for the quartz samples using a JREC automated TL/OSL-reader system installed with a small X-ray

irradiator (Varian, VF-50J tube). All preparations werecarried out under dim red light.
On the other hand, surface soils collected from Ibaraki
were given a dose of 2 Gy by 60Co source at room temperature. The irradiated soils were used in test of P-OSL
dosimetry without quartz extraction.
RESULTS: As shown in the previous KURRI Progress
Report, the ESR signals of Ti-centers ([TiO4/H+]0,[TiO4/Li+]0 and [TiO4/Na+]0), Al-centers and RT-centerswere detected in both quartz samples annealed at 500 and
800ºC. ESR signal intensities of Ti-centers and Al-centerswere decreased with the preheat temperatures but ESR
intensities of RT-centers were randomly changed with thetemperatures.
UVTL and RTL glowcurves, and OSL decay curves
were measured for all kinds of quartz samples. TheUVTL and the RTL intensities were integrated in whole
region of heating temperature. The OSL signal intensity
was estimated by integrating the counts in the first 1 s ofthe decay curve after subtracting the average backgroundestimated from the data in the last 2 s of the OSL curve.
The intensities of the UVTL and the RTL decreased withincreasing preheat temperatures. On the other hand, theintensities of OSL increased up to 250 ºC and then decreased to 300 ºC.
In this research, no clear correlation could be identified
between luminescence intensity and ESR signal intensity.
Therefore, further work is necessary to identify luminescence mechanism using ESR measurement and annealing
experiment.
On the other hand, P-OSL measurement was applied tovarious kinds of surface soils to confirm that a known
dose given in the KURRI could be accurately measured.
However, some samples gave consistent results with the
expected dose but the other samples did not. More P-OSL
research should be required to develop the dosimetry
using standard 60Co source set in the KURRI.
REFERENCES:[1] I. Veronese et al., J. Environ. Radioactiv., 86 (2006)
319-336.
[2] C. Woda, M. Fuchs, Radiat. Meas., 43 (2008) 26-37.
[3] T. Hashimoto et al., BUNSEKI KAGAKU 51 (2002)
527-532.
[4] C. Ankjærgaard et al., Radiat. Meas., 45 (2010)778-785.

採択課題番号 24031 緊急時被ばく線量測定を目指した放射線誘起ルミネッセンスの基礎的研究（原子力機構・核サ研）藤田博喜、（京大・原子炉）阪本雅昭、齋藤 毅

共同通常CO12-4 Thickness and Density of Adsorbed Additive layer onto Metal Surface under High
Temperature and High Pressure Evaluated by TOF-Mode Neutron Reflectometry
T. Hirayama, M. Maeda1, D. Nakano1, T. Matsuoka1, M.
Hino2, M. Kitaguchi2 and T. Oda2
Dept. of Mechanical Engineering, Doshisha University
Dept. of Mechanical Engineering, Doshisha University
2
Research Reactor Institute, Kyoto University
1

INTRODUCTION: Boundary lubrication is one of themost interesting topics in the field of tribology, and therecent development of physical and chemical analyzers
has been accelerating to better understand the behavior ofboundary lubrication films. Under the boundary lubrication, oiliness additives mixed in base oil are expected toform adsorption layers on a sliding surface and thenachieve low friction and high durability. Previous reports
have confirmed that the adsorptive performance of theadditive to the surface greatly affects the friction coefficient of surface. However, physical properties of adsorbed layers are still unknown because of the substantial
difficulty for in-situ analysis.
Our laboratory has proposed applying neutron reflectometry to directly measure physical properties, i.e.,
thickness and density, of adsorption layers formed byacid additives on metal surfaces [1,2]. We report thephysical properties of adsorption layer and introduce ourlatest approach with the development of the TOF-mode
neutron reflectometer for tribology use.
EXPERIMENTS: To widen applications of the neutronreflectometry to tribological studies, a TOF-mode neutron reflectometer was developed at the CN-3 in Kyoto
University Research Reactor Institute (KURRI). A schematic diagram is shown in Figure 1. The carbonization
nickel surfaces with various film thicknesses were deposited on ultra-flat silicon blocks by physical deposition.
The obtained reflectivity profiles in air proved that theresolution of the developed reflectometer for film thickness was under 2 nm. This result proved that the reflectometry has high potential for use in advanced tribological studies on solid-liquid interfaces.
DS

Chopper S1

S2

2θ

RESULTS: The carboxylic groups in the acetic acid in
the lubricant were expected to preferentially adsorb to themetal surface and form a thin layer less than 10 nm thick.
To examine the layer thickness and density using neutronreflectometry with the highest accuracy, we took the following procedure. First, we set the sample surface in thesample holder to obtain a neutron reflectivity profile fromthe interface between the sample surface and air. Second,
the base oil poly-alpha-olefin (PAO) was poured into thesample holder and a reflectivity profile from between thesurface and the PAO was similarly obtained. Finally, theadditive was added into the PAO and mixed in the sample
holder carefully and the reflectivity profile was again
obtained. During the whole experiments, we didn’t touchthe neutron optics and the sample holder at all, and thus
the difference in reflectivity profiles in each step werecompletely recognized as being provided by the existenceof base oil and/or additive at the interface. After theabove procedure, we checked the difference between thereflectivity profiles with theoretical fitting based on Parratt’s theory. The amount of additive mixed into PAO was
0.1 mass%.
The obtained reflectivity profile is shown in Fig. 2.
From the obtained reflectivity profiles, the thicknesses of
the adsorption layer made by palmitic acid onto the copper surface were quite thin, about 1.4 nm. Interestingly,
under hydrostatic pressure of 3 MPa, the thickness ofadsorption layer increased to become about 5.9 nm. The
results are summarized as follows.
(1) Formation of the adsorption layer was clearly observed when the undecanoic, palmitic and stearic acids
were used as additives for each. Particularly, the adsorbed
layers of these acids were expected to be monolayers.
(2) Hydrostatic pressure is possible to encourage to makethe adsorbed layer to be a multilayer.

Shutter
Beam

Sample
1260

150

1110

940
370
2050

2890

Fig. 1. Schematic diagram of reflectometer in KURRI

Fig. 2. Reflectivity profiles from copper surface
REFERENCES:[1] T. Hirayama et al., Trans. JSME, Ser. C, Vol. 77, No.
779 (2011) pp. 2884-2893.
[2] T. Hirayama et al., Tribology International, Vol. 54(2012) pp. 100-105.

中性子反射率法による金属表面上添加剤吸着層の厚み・密度測定（温度・圧力依存特性の把握）（同志社・理工）平山朋子、前田成志、中野大輔、松岡敬（京大・原子炉）日野正裕、北口雅暁、小田達郎
採択課題番号 24035

共同通常CO12-5

Neutron Activation Analysis for Hafnium in Hafnium Oxide Films

T. Takatsuka, K. Hirata, Y. Kobayashi, R. Okumura1 andK. Takamiya1

tector (ORTEC) with an energy resolution around 1.8
keV FWHM at 1333 keV.

National Metrology Institute of Japan, National Instituteof Advanced Industrial Science and Technology
1
Research Reactor Institute, Kyoto University

RESULTS: Figure 1 shows a gamma ray spectrum
obtained from the specimen of hafnium oxide film with
antimony internal standard solution. The peaks ataround 482 keV from 181Hf and 603 keV from 124Sb werefocused to determine hafnium amount in the oxide film.
The counts in each peak were integrated for every specimen and standard, and then the intensities after the decay
correction [2] were used to calculate relative intensities(181Hf cps) / (124Sb cps/ ng). The hafnium content in thespecimen is estimated to be 3.5 µg from the calibration
curve. Considering the surface area of the hafnium oxide film is 98 mm2, the resulting hafnium content is
3.6 µg / cm2.
Uncertainties of the quantification were evaluated fromthe sources as follows: gamma ray counting and the corrections, quantifying from the calibration curve, repeatability of the measurements, preparation of the standards,
and isotope ratio. Total uncertainty of the quantification
was estimated to be 0.92 % of relative standard uncertainty. Finally, certified reference material NMIJ-CRM
5605-a was developed using the results.

EXPERIMENTS: Hafnium oxide films were deposited on 4-inch Si wafers by magnetron sputtering method.
In this study, the nominal thickness is 4 nm with homogeneity within 2 % in a wafer. Several wafers with hafnium oxide film were diced into 10 × 10 mm2 pieces, andseveral pieces were picked-up for measurements.
Hafnium amounts were evaluated by INAA and calculated into area density. The surface area of a specimen
was measured by taking images using a commercial optical scanner with a high resolution. From the images,
the lengths of four sides of the chip were measured to
calculate the surface area. Length calibration was performed by standard scales. For the production of standards to calibrate hafnium amounts, a natural standard
solution was prepared by diluting SRM 3122 (commercially available from NIST) gravimetrically. In addition,a standard solution for internal standard was prepared bydiluting JCSS antimony standard solution gravimetrically.
Portions of the antimony solution were dropped from apolyethylene pipette onto pieces of the cleaned specimen,
while portions of mixed solution (hafnium and antimony
standards) were dropped onto cleaned filter papers. All
specimens and standards were heat-sealed in individual
clean poly-ethylene envelopes and stacked in apoly-ethylene irradiation container. The neutron irradiation was performed for 4 hours at 1 MW in research
reactor KUR of Research Reactor Institute, Kyoto University. Gamma-ray activity of each specimen andstandard was measured by a high-purity germanium de-

181

10

CountsINTRODUCTION: Hafnium oxide (high-k) dielectricfilms are being introduced into silicon-based semiconductor devices in order to achieve higher electronic performance. The front-end processes require the thin dielectric films well-controlled in thickness for gate stacks.
According to the international technology roadmap for
semiconductors 2011[1], thickness of dielectric films
should be controlled in 4 % process range. It becomesdifficult to obtain the accurate thickness in length unit
since the films are getting to be near atomic dimension
and consist of complex structure like interface layers,which may involve atomic fluctuations. Reference materials whose properties are well-calibrated should shedlight on quantification of the film thickness with small
uncertainties. This study aims to quantify hafnium inthin hafnium oxide films by neutron activation analysis
as quantitative method, and to develop reference materials applicable to semiconductor manufacture.

5

Hf

124

Sb

104

103

102

101

0

200

400

600

800

Energy (keV)

Fig. 1. Gamma ray spectrum from the hafniumoxide film with antimony standard solution.
REFERENCES:[1] The International Technology Roadmap for Semiconductors 2011.
[2] G.Gilmore and J. D. Hemingway, Practical gamma-ray spectrometry (John Wiley & Sons, Chichester,
1995.

採択課題番号24044 中性子放射化分析によるハフニウム酸化膜中ハフニウムの定量（産総研・計測標準）高塚登志子、平田浩一、小林慶規

一般通常CO12-6

Mössbauer Microspectrometer for Geosciences

K. Shinoda and Y. Kobayashi1
Department of Geosciences,
Graduate School of Science, Osaka City University
1
Research Reactor Institute, Kyoto University
INTRODUCTION: Fe2+/Fe3+ ratio in minerals is an
important geosciences' information, because the ratio
suggests oxygen fugacities of the mineral formation, highor low temperature oxidation after crystallization, andweathering. Mössbauer spectroscopy is a major method
to detect Fe2+ and Fe3+ in minerals without chemicallydecomposing analyses. Mössbauer spectroscopy is arecoilless atomic nuclear -ray resonance. Although
Mössbauer spectroscopy is a very useful method, it was
not applied to microspectroscopy. This is because there
was no way to focus -ray. Recently, multi-capillary
X-ray lense (MCX) to focus X-ray was developed andapplied to Mössbauer microspectroscopy (Yoshida andSoejima, 2010). The author also started to construct
Mössbauer microspectrometer using MCX for the applications to geosciences. In this report, we introduce
newly developed Mössbauer microspectrometer and-ray beam examination. Although Mössbauer spectrum of Fe foil at 0.5mm was confirmed to be measured
by this Mössbauer microspectrometer, the following
problem remains. The -ray of 121 keV due to a transition from the second to the first excited states radiatesfrom the -ray source 57Co in addition to the 14.4 keV

due to the transition from the first to the ground states.
The 121 keV -ray straightly transmits the MCX andactivates a sample at the focus of MCX and cause X-ray
fluorescence. The X-ray fluorescence results in background of -ray spectra. To cut of the 121 keV as possible, a pinhole plate of Pb needs to be placed at the focus of MCX. S/N ratio can be improved by the Pb pinhole. However, Pb-L fluorescence of 10.6 keV is addedto -ray spectra. The 10.6 keV Pb-L line is closed to
14.4 keV and makes S/N worse. To solve S/N problem,
we are optimizing optical paths of -ray of this Mössbauer microspectrometer.
EXPERIMENTS and RESULTS: Figure1 shows aschematic figure of Mössbauer microspectrometer developed in this study. The -ray source is heavily surrounded by Pb shield to prevent 121keV from spreading.
MCX and pin hole are set on micro-mechanical stage toadjust them to optimized positions. A laser is locatedbehind a transducer to adjust mechanical center of MCX
and pin hole before setting -ray source. Scanning pin
hole of 0.5mmf, focusing point of g-ray by MCX wassearched. At the optimized pin hole position, -ray intensity spectra and Mössbauer spectra of 57Fe enrichedfoil were measured. As a results, improved low background -ray intensity spectra and Mössbauer spectrawith 6 peaks due to magnetic-splitting were confirmed.

Fig.1 A schematic figure of Mössbauer microspectrometer developed in this study.

採択課題番号 24045
顕微メスバウアー分光器の製作と地球科学への応用（大阪市大・理）篠田圭司（京大・原子炉）小林康浩

共同通常

CO12-7

Precise Determination of Br in PP Resin Pellet by
Instrumental Neutron Activation Analysis Using Internal Standardization

T. Miura, R. Okumura1, Y. Iinuma1, S. Sekimoto1 andK. Takamiya1
National Metrology Institute of Japan, AIST
Research Reactor Institute, Kyoto University

1

INTRODUCTION: National Metrology Institute of Japan is responsible for developing certified reference materials (CRMs) and for establishing the traceability of SI(The International System of Units) on chemical metrology in Japan. To establish SI traceability, the primarymethod of measurements should be applied to the characterization of the CRMs. Recently, neutron activation
analysis (NAA) using comparator standard is recognized
as a potential primary ratio method [1]. Despite thepotential of NAA as primary ratio method, the evaluationof the measurement uncertainty is required in any analysis. In general, there are three main components of uncertainty in NAA, that is, sample preparation uncertainty,
neutron flux homogeneity, and gamma ray measurement
uncertainty. Usually, flux monitor is used to correct theneutron flux in-homogeneity. However, although theflux monitor can correct the neutron flux variation using
the count rate of the known amount of the monitor nuclide, it does not reflect the neutron flux of the actual
sample. The most practical method to eliminate neutron
flux in-homogeneity and to improve gamma ray measurement uncertainty is an internal standard method [2].
In this paper, we presented that notable capability of internal standardization in NAA for determination of Br in
polypropylene (PP) resin pellet as a candidate CRM.
EXPERIMENTS: The PP resin pellet candidate CRM
was produced by a mixing machine. The calibration
solution of Br was prepared from NMIJ primary bromide
standard solution. The Au solution for the internal
standard was prepared from a high purity metal. The
calibration solutions contained Br and Au. One hundred mg of the PP resin pellet samples was used for Br
analysis. The Au solution was added to the samples
before neutron irradiation. The neutron irradiations
were performed by KUR (Kyoto University Research
Reactor) PN-3(thermal neutron flux: 4.6 x 1012 cm-2s-1)
for 10 min and TCPn (thermal neutron flux: 8.0 x 10 10
cm-2s-1) for 30 min.

The  ray measurement system consisted of a Canberra
GC4070-7500 Ge detector and a Laboratory Equipment
Corporation MCA600.
RESULTS: It was found that the neutron flux varied
according to the sample position in the irradiation capsule.
The relative standard uncertainty of the in-homogeneity
was estimated to be about 5.1 % by 198Au sensitivity(cps/g) at 411 keV of the internal standard (n=19). The
uncertainty related to the neutron flux homogeneity significantly contributes to the overall uncertainty, if an internal standard is not applied. The calibration curve
linearity was also improved by internal standardization.
The calibration curves of 82Br showed good and sufficientlinearity. The relative uncertainty related to the calibration curve linearity was improved to 0.97 % from 2.0 %for 82Br by using an internal standardization. The analytical results of Br by proposed method were in excellent
agreement with the values obtained by Isotope dilution-Inductively Coupled Plasma Mass Spectrometry(ID-ICPMS). The relative expanded uncertainty (k=2)
was 1.9 %, and it was comparable to that of ID-ICP-MS.

REFERENCES:[1] R.Greenberg, P. Bode, E. De Nardi Fernandes,
Spectrochim. Acta B, 66 (2011) 193-241.
[2] T. Miura, K.Chiba, T. Kuroiwa, T. Narukawa, A.Hioki,
H. Matsue, Talanta, 82 (2010) 1143-1148.

採択課題番号 24048 内標準法を併用した中性子放射化分析法の高精度化に関する研究 共同通常
（産総研・計測標準）三浦勉（京大・原子炉）奥村良、飯沼勇人、関本俊、高宮幸一

CO12-8

Development of Neutron Irradiation Field for Biological Researchby Electron Linear Accelerator

N. Tokunaga, S. Takahashi1, H. Yashima1 and J. Hori1
Graduate School of Agriculture, Kyoto University
Research Reactor Institute, Kyoto University

1

INTRODUCTION: Neutron beams have been used inmany ways, for example, Boron Neutron Capture Therapy (BNCT) and neutron imaging. Nuclear reactor is a
traditional neutron source and recently accelerators havebeen also utilized for it. There are still a lot of problems
to be solved in order to use the neutron beam more effectively and safely. One of them is that we have to learn
more about biological effects on humans and cells interms of radiation protection because neutron is more
effective than photon like gamma ray. The progress of
biological effects research demands a new neutron source
suitable for the study. This research intended to provide
fundamental data to develop a neutron field suitable forbiological research and focused on the distribution ofneutrons and gamma rays from Ta target in measurement
and simulation at KURRI-LINAC.

EXPERIMENTS: Three kinds of metal samples (Al,Ni, and Au) were set around the Ta target and irradiatedwith electron beam generated by KURRI-LINAC. The
first irradiation was operated by 68.5 [uA] for 48.7 hours.
The second one was done by 101.4 [uA] for 72.0 hours.
Some nuclides in these samples were activated by gamma
rays or neutrons from Ta target, whose activities were
determined by Ge detector. It was thought the following
reactions mainly occurred, 27Al(n, a)24Na, 58Ni(n, p)58Co,
197
Au(n, g)198Au and 197Al (g, n)196Au. At the same time,
simulation was done by Monte Carlo Code MCNP [1].
From the result and cross section data, production rate of
the induced activities was calculated.

RESULTS: Fig. 1 to 3 showed the induced radioactivity measured in the experiments as well as calculated by
the simulations. The horizontal axis and vertical one
means the angle from electron beam [degree] and production rate [production/ (electron*atom)] respectively.
In perspective of angular distribution, fast neutrons are
emitted in the all directions from Ta target as well as
thermal ones and gamma rays tend to be mainly done inforward direction. On the other hand, in terms of measurement and simulation, neutrons showed the same trend
and value, especially fast neutrons. These results may
suggest that the samples should be set in backward position where high neutron and low gamma dose rate are
expected.

Fig. 1 Co-58 Production Rate
Ni (n, p) 58Co reaction was trigger by fast neutron.
58

Fig. 2 Au-198 Production Rate
Au (n, g) 198Au reaction was trigger by thermal
neutron.
197

Fig. 3 Au-198 Production Rate
Au (g, n) 196Au reaction was trigger by gamma
ray.
197

REFERENCES:[1] X-5 Monte Carlo Team, MCNP - A General Monte Carlo
N-Particle Transport Code, Version 5, LA-UR-03-1987,
Los Alamos National Laboratory (2003)

採択課題番号 24069 電子線形加速器を用いた生物影響研究用中性子照射場の開発（京大院・農）徳永 直也（京大・原子炉）高橋 千太郎、八島 浩、堀 順一

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CO12-9

Determination of Nitrate Nitrogen Produced Through Photochemical Reaction
Using Brucine Method

T. Kubota and T. Ohta1,
3

Research Reactor Institute, Kyoto University
1
Graduate School of Engineering, Hokkaido University
Absorbance

INTRODUCTION: Nitrogen oxides and ozone areproduced in the atmosphere by the irradiation effect of
UV [1] and the former is dissolved into water to be nitricacid. Similar reactions happen in accelerator facilities andgamma irradiation facilities, and they would be damagedby corrosion.
A large amount of radioactive material was released
into the environment by the Fukushima accident and has
been emitting ionizing radiation. In order to estimate theproduction of NOx by these radioactive materials, in thisreport we produced nitrate nitrogen in the KUR-Linac
and determined nitrated recovered in water with brucine
method [2-3].

10.4 ppm

2.5

1.04 ppm

2

0 ppm

1.5
1
0.5
0
350

400

450

500

550

600

Wavelength / nm

Fig. 1. The absorbance of nitrate nitrogen withbrucine of 17.1 mg/mL
2.0

RESULTS: The absorbance with brucine of 17.1
mg/mL in Fig. 1 shows that nitrate nitrogen of larger than
1ppm is detectable. In the case of the concentration oflarger than 100ppm, however, this brucine concentration
is too high to measure absorbance spectra. Fig. 2 shows
the sensitivity of absorbance measurement by changing
brucine concentration and the detectable concentration of
nitrate raging from 1 to 1000ppm.
The concentration of nitrate trapped into water isshown in Fig. 3. Irradiation in normal operation yieldedthe detectable amount of nitrate; however, neither irradiation in low-energy operation nor irradiation energy lessthan 50 MJ yielded detectable results.
REFERENCES:[1] Y. Sadanaga et al., J. Photochem. Photobio. C, 4
(2003) 85-104.
[2] D. J. D.-Nicholas et al., Methods in Enzymology 3(1957) 981-984.
[3] R P.-Olmosa et al., Talanta 53 (2001) 741-748.

採択課題番号 24090（京大・原子炉）窪田卓見

Absorbance

17.1 mg/mL
0.2 mg/mL

1.5
1.0
0.5
0.0
1

10

100

1000

10000

Nitrate / ppm

Fig. 2. Sensitivity of absorbance at 410 nm bychanging brucine concentration from 0.2 to 17.1
mg/mL
2.0

Nitrate / ppm

EXPERIMENTS: Nitrogen oxide was produced thorough irradiation of air by photon generated with Ta converter in the KURRI-Linac. The peak energy of accelerated electron was regulated 30 MeV (normal operation)and 9 MeV (low-energy operation). The produced nitrogen oxide in the target room was trapped into water (500mL) as nitrate. The concentration of nitrate nitrogen wasdetermined by absorbance (brucine method).
In this brucine method the absorbance of a mixture of
1mL of brucine solution, 2.5 mL of measurement sample,
and 2.5 mL of 16 M H2SO4 was measured at a wavelength of 410 nm (high-purity water as reference). The
sensitivity of this brucine method was investigated at theresulting concentration of brucine of 0.2 and 17.1
mg/mL.

1.5
1.0
30MeV
9MeV

0.5
0.0
0

50

100

150

200

Irradiationn energy / MJ

Fig. 3. Concentration of nitrate nitrogen trapped
into water

光子照射による汚染土壌の回復の検討（北大・工）太田朋子

共同通常

Evaluation of Multiwire-Type Two-Dimensional Neutron Detector
with Individual Line Readout

K. Toh, H. Yamagishi1, K. Soyama, M. Hino2,
M. Kitaguchi2 and T. Oda3
J-PARC center, Japan Atomic Energy Agency
1
Nippon Advanced Technology
2
Research Reactor Institute, Kyoto University
3
Graduate School of Science, Kyoto University

INTRODUCTION: Some neutron scattering experiments performed using a high-intensity pulsed neutron
source require two-dimensional neutron detectors thatcombine challenging performances such as an excellent
spatial resolution, a high detection efficiency, and a highcounting rate. With the objective of finding a neutron
detector that satisfies these requirements, we are currently developing a two-dimensional position-sensitive neutron detection system that can read out individual signal
line and consists of a multiwire-type detector element[1-2]. In the present study, we have performed irradiation
test for the developed neutron detection system. This irradiated system was fabricated for J-PARC/MLF BL17
SHARAKU and this experiment was first irradiation test
for the detector using a collimated neutron beam.
EXPERIMENTS: Neutron irradiation was carried ourusing a CN-3 cold neutron beam line at KUR. The irradiated neutron detection system consists of a 256 channel
multiwire detector element (x: 128 lines, y: 128 lines)
equipped
intoapressure
vessel,amplifier-shaper-discriminator (ASD) boards, optical signaltransmission
devices,
position
encoders
withfield-programmable gate arrays (FPGAs), and a fast dataacquisition device. The pitches of each axis are 1 mm andthe conversion gap is 20 mm. The charge signals collected by the detector element were amplified, shaped, anddiscriminated by ASD application-specific integrated
circuits (ASICs). The nominal settings of the ASD-ASICs
had an amplification factor of 3.1 V/pC and a decay timeof 90 ns. Digital signals from the ASD-ASIC were transmitted to the position encoders via optical fibers as optical signals converted by specially-fabricated E/O-O/E
converters.
RESULTS: An imaging experiment was performed toverify an operation of the position encoder. As an example of the experimental results, a measured
two-dimensional image is shown in Fig. 1. In this experiment, 9 collimated neutron beams with a size of 0.7 x
1.0 mm2, which was determined using a neutron imaging
plate, was irradiated to the detector. It is confirmed thatthe position encoder works well and can be used in neutron detection system. The spatial resolution of our de-tector was less than 2 mm FWHM in both directions.
Considering the Monte Carlo simulation results [1], thisvalue appears to be reasonable. Fig. 2 shows the reactor
power dependence to the measured counts of the developed detector system. The developed detector showed alinear response up to the full power, 5 MW, of KUR reactor and the counting rate at 5 MW was approximately
45 kcps. The linear response for counting rate greaterthan 45 kcps can be observed easily by irradiating with ahigher flux of neutrons, because the counting rate of oursystem was not saturated.

Fig. 1 Two-dimensional response obtained using a collimated beam with a size of 0.7 x 1.0 mm2.
105
104Counts (cps)CO12-10

103
102
101
100
10-1
10-5

10-4

10-3
10-2
10-1
Reactor Power (MW)

100

101

Fig. 2 Measured counts of developed system under neutron irradiation as a function of KUR reactor power.
REFERENCES:[1] H. Yamagishi et al., J. Instrum. 6 (2011) C12025.
[2] K. Toh et al., J. Instrum., 7 (2012) C01025.

採択課題番号 24097 個別信号読み出し MWPC 二次元中性子検出器の特性評価（原子力機構）藤 健太郎、曽山和彦（日本アドバンストテクノロジー）山岸秀志（京大・原子炉）日野正裕、北口雅暁（京大院・工）小田達郎

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