UTTAC-81, 2012UTTAC
ANNUAL REPORT 2011

TANDEM ACCELERATOR COMPLEX
Research Facility Center for Science and Technology
University of Tsukuba

http://www.tac.tsukuba.ac.jp/

UTTACANNUAL REPORT 2011
April 1, 2011 – March 31, 2012

UTTAC-81, 2012

Executive Editor: Eiji Kita
Editors: Yoshihiro Yamato, Daiichiro Sekiba, Kimikazu Sasa, and Tetsuro Komatsubara

UTTAC is a series of issues, which include annual reports of
Tandem Accelerator Complex, Research Facility Center
for Science and Technology, University of Tsukuba.
The issues may also include irregular reports written by English.
Copyright © 2012 by Tandem Accelerator Complex, Research Facility Center
for Science and Technology, University of Tsukuba and individual contributors.
All reports are written on authors’ responsibility and thus the editors are not liable
for the contents of the report.

Tandem Accelerator Complex, Research Facility Center for Science and Technology,
University of Tsukuba
Tennodai 1-1-1, Tsukuba, Ibaraki 305-8577, Japan
http://www.tac.tsukuba.ac.jp/
annual@tac.tsukuba.ac.jp

PREFACE
This annual report covers researches carried out at Tandem Accelerator Complex,
Research Facility Center for Science and Technology, the University of Tsukuba (UTTAC),
during the fiscal year 2011 (April 1st 2011 ∼ March 31st 2012). Since the 12UD Pelletron tandem
accelerator has been completely destroyed by the Great East Japan Earthquake on March 11th
2011, contents of this volume are limited to the researches by use of the 1 MV Tandetron
accelerator and 57Co Mössbauer spectroscopy. Then, the number of pages of this volume
becomes a little fewer than those of the older volumes.
The government has been supporting repairs and maintenances for damaged buildings andfacilities, and our 12UD accelerator was also covered by the reconstruction budget through the
Ministry of Education, Culture, Sports, Science and Technology Japan (MEXT). The damage ofthe 12UD accelerator was, however, too serious and severe to repair. Therefore, we gave it up
and decided to replace by a new 6 MV tandem accelerator. It is now under construction by NEC(National Electrostatics Corporation, at Middleton, Wisconsin, USA). The expecting datearriving at Tsukuba will be around the spring of 2014. We are looking forward to operating the
new 6 MV accelerator and reporting about it.

December 1st 2012
Editors-i-CONTENTS

1. ACCELERATOR AND EXPERIMENTAL FACILITIES
1.1 Accelerator operation (2011).·········································································

1

1.2 Post-quake reconstruction project of the Tandem Accelerator Facility at the University ofTsukuba ·································································································
1.3 Development of rotating magnetic field applying system for β-NMR method ···············

3
5

2. NUCLEAR PHYSICS
2.1 Measurement of the astrophysical S-factor for the reaction 7Li(3He, p)9Be at 3MeV·········

7

2.2 The study of nucleosyntesis by means of scandium-45 + p reaction·····························

9

3. MATERIAL AND CLUSTER SCIENCE
3.1 Hydrogen uptake process in a-C:H film growth studied by RBS-ERDA with hydrogenisotope ···································································································
3.2 Droplet formation in N2/H2O/SO2 by corona discharge ··········································

11
12

3.3 Measurement of secondary electron yields with a micro-channel plate or the study ofcluster effects ···························································································

14

3.4 Investigation of layer thicknesses in CaF2/Fe3Si heterostructures grown on Si(111)substrates by molecular beam epitaxy ·······························································

16

3.5 Conversion electron Mössbauer spectroscopy (CEMS) study of an iron oxide thin film
fabricated by reactive sputtering ·····································································

18

3.6 Mössbauer analysis of Mg-containing Fe3O4 nanoparticles for magnetic hyperthermia ·····

20

4. INTERDISCIPLINARY RESEARCH
4.1 Direct characterization of hydrogen content in MLCC employing elastic recoilcoincidence spectroscopy ·············································································

23

5. LIST OF PUBLICATIONS
5.1 Journals ··································································································

27

5.2 International conferences ··············································································

32- iii -

6. THESES ·········································································································

34

7. SEMINARS ····································································································

36

8. SYMPOSIUM ·································································································

37

9. LIST OF PERSONEL ·······················································································

39- iv -

1.
ACCELERATOR AND EXPERIMENTAL FACILITIES1.1

Accelerator operation 2011

K. Sasa, S. Ishii, H. Kimura, H. Oshima, Y. Tajima, T. Takahashi, Y. Yamato,
T. Komatsubara, D. Sekiba and E. Kita.
The 12UD Pelletron tandem and the 1 MV Tandetron accelerators have been operated and maintainedat the University of Tsukuba, Tandem Accelerator Complex (UTTAC). However, the 12UD Pelletron
tandem accelerator suffered serious damage from the Great East Japan Earthquake on 11 March 2011. We
decided to shut down the 12UD Pelletron tandem accelerator on January 2012. The 1 MV Tandetron
accelerator did not have any serious damage, therefore we used only the 1 MV Tandetron accelerator forexperimental researches in 2011.
The total service time of the UTTAC multi-tandem accelerator facility was 1,968 hours in the fiscal
year 2011. 34.9 percent (686 hours) of the total service time were used for industrial users under the
project "Promotion of Advanced R&D Facility Utilization", which was supported financially by the
Ministry of Education, Culture, Sports, Science and Technology (MEXT) of JAPAN. In the project, a totalof 11 research programs were conducted in 2011.
The 1 MV Tandetron accelerator
The operating time and the experimental beam time of the 1 MV Tandetron accelerator were 826.5
and 380.6 hours, respectively, during the total service time in 2011. A total of 68 research programs werecarried out and a total of 677 researchers used the 1 MV Tandetron accelerator. Fig. 1 shows thepercentage of accelerated ions for the 1 MV Tandetron accelerator. Fig. 2 shows the percentage of theexperimental beam time for the running research fields.

Ccluster
20.5

H
39.7 %

C
7.5

He
32.3

Fig.1. Percentage of accelerated ions for the 1 MV Tandetron accelerator in 2011.

1

Education
1.0

Accelerator
Science
1.5

Developments(Instruments andDetectors)
11.0

RBS・ERDA
13.5 %
PIXE
4.4

Innovation

NRA
11.0
RBS･ERDA(Innovation)
18.0
Cluster
Physics
29.8
NuclearPhysics
9.6

Fig.2. Percentage of the experimental beam time for the running research fields
with the 1 MV Tandetron accelerator in 2011.

2

1.2
Post-quake reconstruction project of the Tandem Accelerator Facility
at the University of Tsukuba
K. Sasa, S. Ishii, H. Kimura, H. Oshima, Y. Tajima, T. Takahashi, Y. Yamato,
T. Komatsubara, D. Sekiba and E. Kita.
We are planning to install a new middle-sized tandem accelerator at the 2nd experimental room insteadof the broken 12UD Pelletron tandem accelerator. The renewed tandem accelerator system will widely beapplied for AMS, IBA, beam irradiation research and nuclear physics.
In 2011, we repaired damaged experimental rooms and leaky roofs by the earthquake. Fig. 1 shows aphoto of the 2nd experimental room under repair. After restoration, we removed all beam lines in the 2nd
experimental room in order to construct the renewed tandem accelerator system. Fig. 2 shows the current
state of the 2nd experimental room.

Fig. 1. A photo of the 2nd experimental room

Fig. 2. Current state of the 2nd experimental

under repair.

room after removal of all beam lines.

The renewed tandem accelerator system will consist of a horizontal type 6 MV Pelletron tandem
accelerator, new 4 ion sources and the polarized ion source, an accelerator mass spectrometry system andan ion beam analysis system. The 6 MV Pelletron tandem accelerator is designed by the National
Electrostatics Corp., USA. Fig. 3 shows the schematic view of the 6 MV Pelletron tandem accelerator. The
accelerator tank is about 8.8 m long and 2.7 m in diameter.

Fig. 3. Schematic view of the 6 MV Pelletron tandem accelerator designedby the National Electrostatic Corp., USA.

3

The polarized ion source was damaged in the earthquake. After restoration of the polarized ion source, itwill be moved from the 9th floor to a new experimental booth at the ground. A high energy beam transportline will be connected from the new tandem accelerator to the present experimental facilities in the 1st
experimental room. The beam transport line will intersect with another beam line for AMS and IBA in the
2nd experimental room. Fig. 4 shows the layout of the new 6 MV tandem accelerator system. The AMS
system will be capable of measuring environmental levels of long-lived radioisotopes of 10Be, 14C, 26Al,
36

Cl, 41Ca and 129I. The IBA system will be equipped with a high-precision five-axis goniometer. The

construction of the new 6 MV tandem accelerator system is scheduled in the spring of 2014. The beam
delivery will start on September 2014.

First floor design

Polarized Ion Source (PIS)

1st room

2nd room

Cs sputter
IS

AMS
IS

AMS
IS

Nuclearphysics

NuclearAstrophysics

AMS

RF
IS

IBA

23.5 mGeneralpurpose

High energy
beam transport

6 MV
tandem55°
Microbeamhydrogen analysis

Biologicalirradiation

Heavy ion
nanoengineering

90°
105°

Atomicphysics40°

13.5 mPositronannihilation

Fig.4. Layout of the new 6 MV tandem accelerator system.

4

1.3

Development of rotating magnetic field applying system for β -NMR
methodT. Niwa, D. Nagae, Y. Abe, Y. Ishibashi, and A. Ozawa
The spin parity as well as the sign of magnetic (µ ) moment are basic probes to obtain information
about the nuclear structure throughout the entire nuclear chart. To determine a spin parity and a sign ofµ moment, a laser spectroscopy[1] and decay spectroscopy[2] are mostly used. However, these measurements are limited to the specific nuclei due to some experimental restrictions especially nuclei located far
from β stability region. For this region, the β -ray detected nuclear magnetic resonance (β -NMR) technique is a powerful method measuring an absolute µ moment[3, 4]. In order to determine the sign of µmoment, a β -NMR technique using rotating magnetic field is developing.
In the β -NMR technique, the µ moment is deduced from a frequency of the NMR. The NMR ismeasured by a detection of the NMR effect which arises in the asymmetric angular distribution of β -rayemission from spin-polarized radioactive nucleus. The resonance frequency ν under a only static magnetic
field B0 is given by ν = gµN B0 /h, where g, µN , and h denote a g factor, the nuclear magneton, and the
Planck’s constant, respectively. The µ moment µ = gµN I is determined from the measured values ν andB0 and spin I which is a spin of the magnetic sublevel. In a rotating coordinate system with a rotation~ , the equation of motion for the µ moment is expressed using γ = gµN /h as
angular frequency ω
(
)
~
∂ ~µ
ω
~
~
= γ µ × B0 += γ~µ × ~Beff .
∂t
γ

(1)

~ = −γ ~B0 = ω~ 0 so that ~Beff ≡ ~B0 + ω~ /γ = 0, we obtain ∂ ~µ /∂ t =When we choose the rotation frequency ω~ =ω~ 0 . Let us suppose that
0. This result shows that ~µ is precessing around ~B0 with an angular velocity ω~1 which is perpendicular to the static magnetic field is applied to the nucleus.
a rotating magnetic field B
When the frequency of the field is corresponds to the resonance one for the nucleus, the direction ofits spin polarization is changed by the NMR. Usually, an oscillating magnetic field can be created as asuperposition of right- and left-rotating magnetic fields. When one of these two components matches the~ 0 . Since the latter~ ≈ω~ 0 , the other component should rotate with frequency ≈ −2ω
resonant frequency ωcomponent produces only a negligible effect on the motion of spin because of the high apparent frequency~ 0 , we can just neglect it. Since the applied magnetic fields are oscillating, we canft determine which
2ω
component matches the resonance condition. Thus, only the absolute µ moment can be deduced by thismethod. In order to determine the sign of the µ moment, applying rotating magnetic field is needed.
In order to apply the rotating magnetic field, we have developed a new RF application system asshown in Fig. 1. The rotating magnetic field is obtained using two pairs of coils. The radius of coil andthe distance between a pair of coils are 20 mm and 24 mm, respectively. The phase-angle difference of
the alternating currents for both pairs of coins is 90 degree. Thus a composed magnetic field is circularpolarized. By changing the phase-angle difference, a right- or left-circularly polarized magnetic field
can be produced. A waveform appropriate for the rotating magnetic field was generated by a Function
Generator (F. G.). The signal from the F.G. was split into two. One of them was fed to a pair of coils
through an attenuator and a 300-W RF power amplifier. Another signal was fed into a phase shifter where5StopperRF coils

᳸F. G.
phase shiftter

attenuator AMP

Variable
capacitor

Osilloscope(RF monitor)

pickup coilFig. 1. Block diagram of the RF system for rotating magnetic field.

the phase angle was shifted by 90 degree. This signal was fed into another pair of coils via an attenuatorand a 300-W RF power amplifier.
In order to confirm the production of the rotating magnetic field, a pickup coil is used. The pickup
coil oriented by 45 degree with respect to the pairs of coils was located at the stopper position as shown in
Fig. 1. Figure 2 shows a current without the phase shifter, a current with the phase shifter, and an output
of pickup coil. A production of a rotating magnetic field including a liner component was confirmed by
the output of pickup coil. Further efforts to measure a polarization of the rotating magnetic field are now
in progress.
output of pickup coilwith phase shifter

without phase shifter

40 nsFig. 2. A typical output of pickup coil with current with/without the phase shifter.

References[1] G. Huber et al., Phys. Rev., C18, 2342(1978).
[2] D.T. Yordanov et al., Phys. Rev. Lett. 99 212501(2007).
[3] K. Sugimoto et al., J. Phys. Soc. Jpn. 21, 213(1966)[4] H. Ueno et al., Phys. Lett., B615, 186(2005).

6

2.
NUCLEAR PHYSICS

2.1

Measurement of theLi(3He,p)9Be at 3MeV.

astrophysicalS-factorforthereaction

7

T. Yuasa, T. Komatsubara, T. Oonishi, K. Sasa, S .Kubono1, T. Hayakawa2, and T. Shizuma2
The observations [1] of metal-poor halo stars indicate that the primordial abundances of 7Li may not bein agreement with the prediction of standard big bang nucleosynthesis (BBN), where the prediction should
be consistent to the baryon-to-photon ratio inferred from analysis of the Wilkinson Microwave Anisotropy
Probe (WMAP) power spectrum. It suggests that the predicted vale of the abundance of 7Li is about 3
times higher than the observed value [2]. The 7Li yield is determined from a balance between production
and destruction reactions. An accurate knowledge of both type of reactions is necessary for cosmologicalmodel calculations to be reliable. Previously, the astrophysical S-factor for the reaction 7Li(3He, p)9Be wasmeasured in low energy region [3-6]. But there is a missing region where no data were reported, so wehave started the study to measure the astrophysical S-factor in this region.
First we have no experience to accelerate 3He ions with the 1 MV Tandetron, we carried out test
experiment using the ions. Although it was the first time to accelerate 3He beam, we got stable and highcurrent beam. During the test, we measured the reaction 7Li(3He,p)9Be at 3 MeV. The target was made byevaporating lithium carbonate on a carbon film of 20 µg/cm2.

Reaction products were detected with a

E-ΔΕ counterFig 2. Contour-map of the same counter fortelescope for a carbon target. Protons froma natural lithium carbonate target with12

carbon backing. Protons and deuterons can

Fig

1.
3

Contour-mapof

14

C( He, p) N reaction can be observed..

be seen.

1

Center for Nuclear Study, Univ. of Tokyo (CNS)

2Japan Atomic Energy Agency (JAEA)

7

standard two-detector telescope of silicon surface barrier detectors. The front ΔE detector had a thicknessof 150µm and the back E detector had a thickness of 500µm. We made a two-dimension plot of energy E
vs energy loss ΔE. Fig.1 shows the result using a carbon target alone and Fig.2 shows the result using
lithium carbonate with the carbon backing. In Fig.2 scattered protons and deuterons are well separately
observed as two lines. The groups A, B, C, D, E and F correspond to the reactions 6Li(3He,p0)8Be,
6

Li(3He,p1)8Be, 7Li(3He,p0)9Be, 7Li(3He,p1)9Be, 12C(3He,p)14N and 7Li(3He,d)8Be, respectively.
Since the natural lithium contains 92.5% of 7Li and 7.5% of 6Li, and Q-value of (3He,p) reaction ishigher for 6Li than 7Li, which are 16.78 MeV and 11.20 MeV, respectively, the protons scattered from 6Li
are quite disturbing. More progressive studies are planned to measure the astrophysical S-factors for thereaction 7Li(3He,p)9Be with more lower energy beam and an enriched isotope target.
References[1] Asplund, M., Lambert, D. L., Nissen, P. E., Primas, F., & Smith, V. V. 2006, Apj, 644, 229.
[2] M. Kusakabe et al.,Astrophys. J. 680. 846-857(2008).
[3] J. Yan et al., Phys. Rev. C65 (2002) 048801.
[4] D. P. Rath et al., Nucl. Phys. A515, 338 (1990).
[5] M. F. Werby and S. Edwards, Nucl. Phys. A213, 294 (1973).
[6] R. L. Dixon and R. D. Edge, Nucl. Phys. A156, 33 (1970).

8

2.2

The study of nucleosynthesis by means of scandium-45 + p reaction

T. Onishi, T. Komatsubara, T .Yuasa, K. Sasa, S .Kubono1, T. Hayakawa2, and T. Shizuma2
Elements lighter than iron are created by the following process in stars. At initial stage of
nucleosynthesis, p-p chain, triple-alpha reaction and alpha-burning occur. Subsequently, carbon, oxygen,neon and silicon burning proceed in massive star and various elements to iron are created. We took aninterest in silicon burning. The silicon burning starts from photodisintegration by high-energy gamma-ray
and alpha-capture of silicon. Then, various elements are created through quasi-equilibrium process. The
reaction flow of quasi-equilibrium process is complex and there are many reactions around scandium-45[1]. The aim of our study is to measure reactions around scandium-45 which is known as a bottleneck insilicon burning. Woosly[1] pointed out that the flow is concentrated to4542Ca(alpha,p)45Sc andSc(p,gamma)46Ti reaction. In order to evaluate nuclear reaction rate of the 42Ca(alpha,p)45Sc, we have

performed measurements of the cross section for the inverse reaction of 45Sc(p,alpha)42Ca(Q-value =2.34MeV). For this reaction, the experimental data were limited only above 2.8MeV [2]. Therefore, wemeasured 45Sc(p,alpha)42Ca reaction with proton beam of 2MeV.

This energy corresponds to Gamow

peak at a temperature of 3GK in silicon burning.
Our measurements were carried out by 1MV Tandetron accelerator at UTTAC. The proton beam of
2MeV was irradiated on scandium target.

The scandium target was prepared by evaporation in vacuum

2

on to 1.47 mg/cm gold backing. The thickness of scandium layer was measured to be 0.2mg/cm2.
Alpha-particle from 45Sc(p,alpha)42Ca reaction was measured at angle of 148°with E-Δ E counter by using
SSD. Accumulation of the measurement is about 7.5 hour.
As a result, alpha-particle from 45Sc(p,alpha)42Ca reaction was separately measured from strong elastic
scattering of protons mainly by the gold backing. The yields of alpha-particle are corrected by dead timeof DAQ and evaluated to be 67 counts. The relation of the yield and the cross section is represented byfollowing equation,

dσ
Ω
dΩ

=

where Y is yield, n is number of incident proton, N/S is particle area density of scandium45, dσ/dΩ isdifferential cross section and Ω is solid angle. The differential cross section calculated by using thisequation isdσ= 0.0066 ± 0.0010[mbarn/sr]dΩ
at angle of 148°.
1

Center for Nuclear Study, Univ. of Tokyo (CNS)

2Japan Atomic Energy Agency (JAEA)

9

Fig.1 shhows the com
mparison of differential cross section
n between ou
ur result andd the experim
mental datareported inn ref [2] meaasured at 125
5°. Our resullt seems to beb the value extrapolatede
to lower eneergy regionof the preevious reportts. In Fig.2 the compariison of astro
ophysical S-ffactor is shoown. The astrophysicalS-factor off previous reeports decreases as protonn energy decrease and is lower than oour result.
Howeveer, since manny resonancee structures ccan be expeccted, we are planning to perform measurementsof detailedd excitation functionfand angular distrribution.

Fig.2
2. comparisonn of astrophysiical S-factor

F
Fig.1. compariison of differeential cross secction

Referencees[1]S.E. Wooosly, W. Daavid Arnett, Donald
D
D. Cllayton

Astrrophys J.S.23
31,26(1973) 231-312[2]J.S. Schhweitzer, Z.E
E. Switkowak
ki, R.M. Wieeland

NPA 287 (1977) 344
3

10

3.
MATERIALS AND CLUSTER SCIENCE

3.1

Hydrogen uptake process in a-C:H film growth studied by RBS-ERDA
with hydrogen isotope

D. Sekiba, N. Takemoto, M. Okada, S. Ishii, T. Sakurai, K. Akimoto
The hydrogen concentration in the hydrogenated amorphous carbon (a-C:H) film strongly affected themechanical and electronic properties of the film. During the film deposition, H2 gas is often added into theprocess gas such as CH4 and C6H6 to control the hydrogen concentration, though the origin of thehydrogen in the film has not been well understood. We investigated the hydrogen uptake process during
the a-C:H film deposition by using D2 and CH4 to distinguish the origin of hydrogen. The concentration of
H and D in the film was determined by elastic recoil detection analysis (ERDA) [1].
The films were deposited on the Si substrate by reactive RF magnetron sputtering with D2 and CH4. The
RF power and frequency were set at 150 W and 13.6 MHz, respectively. The typical thickness of the filmis ~ 200 nm. The partial pressure of CH4 and Ar were set at 1.6 x 10-1 Pa and 4.0 x 10-2 Pa, respectively,
while that of D2 was changed between 0.25 x 10-2 ~ 10.0 x 10-2 Pa. ERDA and Rutherford backscattering
spectroscopy (RBS) were taken at the 1MV Tandetron in UTTAC. The 2.5 MeV 4He2+ ions were irradiatedto the sample with the angle of 75 degree from the surface normal. The recoiled and backscatteredparticles were detected by Si surface detector (SSD) at the angles of 30 and 150 degree with respect to thebeam incident direction. The schematics of the setup are found elsewhere [2].
Figure 1 shows the determined H and Dconcentration as a function of partial pressure ratioof D2 with respect to the total pressure. We can seethat the D concentration in the film is linearly
increased with increasing the D2 molecules in thechamber. On the other hand, H concentration
decreases with decreasing the CH4 molecules in thechamber, so that the total concentration of H+D isalmost constant independently of the D2 partialpressure. We can conclude that the H atom isprovided both from CH4 and H2 in the process gas
and the degree of the contribution is determined by
Fig.1. H and D concentration as a function ofpartial pressure of D2 in the process gas.

the number of molecules instead of the number ofatoms.
References[1] D. Sekiba, N. Takemoto, M. Okada, S. Ishii, T. Sakurai, K. Akimoto, Diamond and Related Materials,
27-28 (2012) 60-63.
[2] D. Sekiba, M. Horikoshi, S. Abe, S. Ishii, Journal of Applied Physics 106 (2009) 114912.

11

3.2

Droplet formation in N2/H2O/SO2 by corona discharge

I. Harayama, H. Tanikawa, S. Funada, K. Sasa and S. Tomita
In 2000, it was reported by Svensmark et al. [1] that the intensity variations of galactic cosmic ray(GCR) could have certain correlation with the coverage of earth’s surface by low-level clouds in theatmosphere. As a possible key process of the correlation, the process of aerosol formation induced by
GCR has attracted attentions. A fraction of these aerosols could grow as cloud condensation nuclei,
which would enhance the earth’s coverage by low-level clouds. To investigate the aerosol formation
process by GCR, we have measured the small droplet formation by 20 MeV protons, and shown thatoxidation process of SO2 play an important role. Sulfuric acid (H2SO4) is known as an importantcomponent for the nucleation process [2], which is normally produced from SO2 in the atmospherethrough the oxidation process. In order to improve our knowledge of the mechanism, we plan togenerate droplets with a corona discharger where only unipolar ions are generated. The experimentstudy using the corona discharger would help us to understand the role of positive and negative ions in
the oxidation process. In this report, we show our preliminary results with new experimental apparatus
using a corona discharger.
The schematic drawing of the corona discharger is shown in Fig. 1. The corona discharger had a needle
and a plate electrode with a hole of 3 mm in diameter. As the needle electrode, we employed a stainlesssteel pin which was held at high voltage of a few kV so that corona discharge takes place. The electricalmobility of the generated aerosols in the sample gas was measured by a differential mobility analyzer(DMA), and SO2 analyzer (Thermo, Model 43i) was used to measure concentration of SO2.
The time variation of the concentration of SO2 in the sample gas is shown in Fig.2. It is clearly seen thatthe concentration of SO2 becoming lower while corona discharge takes place. This means that theconsumption of SO2 is caused by the oxidation process of SO2. The typical spectrum of electrical mobilityof aerosols with same experimental condition is shown in Fig. 3. The spectrum has a peak aroundelectrical mobility of 5 × 10-6 m2/Vs. The droplet density can be obtained by integrating the spectrum. We
plan to study more detail on the relationship between consumption of SO2 and droplet density.

Fig.1. The schematic of corona discharger.

12

Discharge start

Discharge stopSO2 concentration (ppb)

155

150

145

140

2000

3000

4000

5000

Time (sec)Fig.2. The concentration of SO2 in sample gas. The corona current was 4.0 μΑ.
The measured relative humidity of the sample gas was 30%, and the concentration of SO2 was 150 ppb.
The broken lines indicate the times when corona discharge started and stopped.
Particle diameter i(nm)
10

1

1000

Current (fA)

800

600

400

200

0
10-7

10-6

10-5

10-4

2

Electrical mobility (m /Vs)

Fig.3. The spectrum of electrical mobility of droplets. The corona current was 4.0 μA.
The measured relative humidity of the sample gas was 30%, and the concentration of SO2 was 150 ppb.
References[1] N D. Marsh and H. Svensmark, Low Cloud Properties Influenced by Cosmic Rays. Phys. Rev. Let. 85,
5004-5007, 2000
[2] John H. Seinfeld and Spyros N. Pandis, Atmospheric Chemistry and Physics: From Air Pollution to
Climate Change, Second Edition. John Wiley & Sons, Inc, 2006

13

3.3

Measurement of secondary electron yields with a micro-channel plate
for the study of cluster effects

Y. Shiina, S. Tamura, I. Harayama, K. Yamazaki, K. Sasa, S. Ishii and S. Tomita
When fast cluster ions impinged on a material surface, the secondary electron yields are suppressedstrongly compared to those of atomic ions [1]. This is an example of phenomena called cluster effects. It isalready known that cluster effects on energy losses are so weak compared with those on secondary
electron yields [2], while secondary electron yields under irradiation of atomic ions are known to be
proportional to their electronic energy loss over a broad range of energy and target material [3]. Therefore,
it seems that the cluster effect on secondary electron emission stems mainly from the transport ortransmission process, rather than the production process. But the details of the suppression mechanism are
not understood yet. For the further investigation, the coincidence studies with, for example, the orientationof injected molecules, and inter atomic distance between the constituent atoms are thought to beimportant.
We recently constructed a new experimental setup with a micro-channel plate (MCP) together with an
SSD, which enables us event-by-event measurements of secondary electron yields in coincidence with
scattered ions. This report is the result of test measurements with fast protons and carbon cluster ions.
The experimental setup is shown in Fig. 1. Projectiles were delivered from the 1 MV Tandetron
accelerator at UTTAC. The accelerated ions were injected to a thin carbon foil of 5.3 μg/cm2 in thickness.
At the downstream of the target, an SSD was placed for the detection of transmitted ions. On the other sideof the target, a grid was placed and held at +200 V, so that the secondary electrons were extracted andinjected into the MCP. The secondary electron yield is obtained event by event by measuring the
integration of the MCP signal using a charge sensitive amplifier. The measured secondary electron yields
of proton injection (0.5 - 1.7 MeV) are shown in Fig. 2 as a function of electronic stopping power
calculated with SRIM code. The results agree with those reported by Rothard et al. [3]. We also performed
the same experiment with fast carbon clusters (0.5 MeV/atom, cluster size n = 1 - 4), and the results areshown in Fig. 3 as a function of cluster size. It is clearly seen that the secondary electron yield decreases
as the number of ions in a cluster increases. The reduction of the secondary electrons agrees quite wellwith that reported by Arai et al. [1].

14Micro-channel plate(In +200 V, Out + 2200 V)

Grid (+ 200V)

SSD

Faint

Faraday cup

beam

Aperture (φ 2 mm)

TargetpA
2(Ground, 5.3-μg/cm C foil)

2.0
1.0

Y(Cn )/(nY(C ))

+

1.5
1.0

0.5

+

Average of secondary electron yields

Fig. 1. A schematics of the experimental setup

0.5
0.0
0.0

0.1

0.2

0.3

0.4

0.0

0.5
2

0

1

2

3

4

Stopping power (keV/(μg/cm ))Cluster size

Fig. 2. Stopping power dependence of secondary
electron yields by protons: the circles are thepresent data, and the squares are the results reported
by Rothard et al. [3].

Fig. 3. Cluster size dependence of secondary
electron yields per atom by carbon clusters: thecircles are the present data, and the triangles are theresults reported by Arai et al. [1].

References[1] H. Arai, H. Kudo, S. Tomita and S. Ishii, J. Phys. Soc. Jpn. 78, 104301 (2009).
[2] S. Tomita, M. Murakami, N. Sakamoto, S. Ishii, K. Sasa, T. Kaneko and H. Kudo, Phys. Rev. A 82,
044901 (2010).
[3] H. Rothard, K. Kroneberger, A. Clouvas, E. Veje, P. Lorenzen, N. Keller, J. Kemmler, W. Meckbach
and K. O. Groeneveld, Phys. Rev. A 41, 2521 (1990).
[4] H. Rothard, K. Kroneberger, M. Burkhard, J. Kemmler, P. Koschar, O. Heil, C. Biedermann, S.
Lencinas, N. Keller, P. Lorenzen, D. Hofmann, A. Clouvas, K. O. Groeneveld and E. Veje, Radiat. Eff.
Defects Solids 109, 281 (1989).

15

3.4

Investigation of layer thicknesses in CaF2/Fe3Si heterostructures grownon Si(111) substrates by molecular beam epitaxy

K. Harada, K. Toko, T. Suemasu, N. Takemoto, S. Ishii, M. Matsumura, S. Yamazaki, D. Sekiba

Introduction
Ferromagnetic silicide Fe3Si is an attractive material for Si-based spintronics applications because thelattice parameter of Fe3Si is 0.564 nm, which nearly lattice-matches Si. Furthermore, Fe3Si has a relatively
high Curie temperature of approximately 803 K [1]. We have achieved a magnetoresistance (MR) ratio of
0.28% at room temperature (RT) in the Fe3Si/CaF2/Fe3Si magnetic tunnel junction (MTJ) structures [2].
To enhance the MR ratio, we need to process the MTJs into a much smaller-sized mesa structure to avoid
inclusion of defects in the device area using the Ar ion milling technique. Thus, it is important to know theexact thickness of each layer in the MTJs. For this purpose, we attempted to evaluate the thickness oflayers in the MTJs by Rutherford backscattering spectrometry (RBS) measurement. The integrated
intensity of RBS spectrum depends on the thickness of layers.

Experimental
We fabricated four MTJs samples by molecular bean epitaxy (MBE). Growth conditions of samples by
MBE were summarized in Table 1. Fe3Si/CaF2/Fe3Si MTJ structures are for samples A, B and C,
Fe/CaF2/Fe3Si MTJ structure is for sample D. The thickness of each layer in these samples was determinedby RBS measurement using SIMNRA at the C-course of the 1MV Tandetron accelerator in UTTAC.
Table 1 Growth condition of samples.
SampleSi buffer
Deposition Annealing

Thermal cleaningSub.

15 min800 ˚C(Si supplying)n-FZ Si(111)(1000-5000 Ω・cm)

CaF2 buffer
Deposition Annealing

Sample A
Sample B
Sample C

10 nm
350 ˚C

20 min1000 ˚C--

Sample D
SampleSample A
Sample B
Sample C
Sample D

Fe3Si bottom layer
Deposition
15 nm
80 ˚C
15 nm
130 ˚C
15 nm
130 ˚C
15 nm
130 ˚CCaF2 barrier layer

Annealing Deposition Annealing
2 nm
280 ˚C
20 min300 ˚C5 nm
280 ˚C2 nm
200 ˚C5 nm
280 ˚C

Fe3Si top layer

20 min300 ˚C
20 min300 ˚C

Deposition
9 nm
80 ˚C
10 m
80 ˚C
15 nm
130 ˚C

Annealing
30 min280 ˚C
30 min250 ˚C
20 min300 ˚C

-

-

-

-

16

20 min300 ˚C

Fe
layer
9 nm
~ 40 ˚C
10 nm~ 40 ˚C
15nm~ 40 ˚C
15nm~ 40 ˚CPtlayer

3 ~ 5nm~ 40 ˚CResults and Conclusion
Figure 1 shows the RBS spectra of the samples. Pt, Fe, Ca and Si spectra were clearly observed in eachsample. We next estimated the thickness of each layer in the MTJs using SIMNRA. The RBS spectra were
well fitted by the calculation. Table 2 shows the results of calculation for each sample. Reasonable results
were obtained from these calculations in comparison with the growth conditions shown in Table 1.

Fig. 1 RBS spectra of samples A-D.
Table 2 Layer thickness (nm) in samples A-D investigated by RBS.
Layer

Sample A

Sample B

Sample C

Sample D

Pt layer

2.3

0.78

4.0

7.1

Fe layer

8.4

10.0

17.6

13.6

Fe3Si top layer

8.8

10.1

12.1

-

CaF2 barrier layer

1.3

0.77

2.1

0.65

Fe3Si bottom layer

18.1

17.3

18.9

12.9

CaF2 buffer layer

6.5

3.7

1.3

2.0

Si(111) sub.

References[1] A. Ionescu, C. A. F. Vaz, T. Trypiniotis, C. M. Gürtler, H. Garcia-Míquel, J. A. C. Bland, Phy. Rev.
B 71 (2005) 094401.
[2] K. Harada, K. S. Makabe, H. Akinaga, and T. Suemasu, J. Phys. Conference Series 266 (2011)
012088.

17

3.5

Conversion electron Mössbauer spectroscopy (CEMS) study of aniron oxide thin film fabricated by reactive sputtering

M. Minagawa1 , M. Myoka, H. Yanagihara and E. Kita
Iron oxides with spinel structures have been studied by many researchers since the beginning of themagnetism research. The physical and magnetic properties of iron oxides can be controlled by using additional elements, and thus, magnetic materials with various magnetic characteristics from hard to soft
magnetism can been realized. For modern applications of magnetic materials, such as high-density magnetic recording media and spintronics devices, thin films are highly desired. Hence, thin films of spinel
ferrites have been fabricated by a variety of techniques such as chemical vapor deposition (CVD) in earlyyears, and reactive vapor deposition in which atomically-flat surfaces were achieved[1].
In the previous works, we have used O2 and/or O3 gas as reaction sources in the molecular beam epitaxy (MBE) and obtained Fe3 O4 and γ-Fe2 O3 epitaxial films[2]. Metastable γ-Fe2 O3 was only obtainedin the films with limited thickness[3] of less than 130 Å and these films’ good quality resulted in antiferromagnetic interlayer couplings in Fe/Fe3 O4 or Fe/MgO/γ-Fe2 O3 epitaxial films. The coupling energy
was about 1.5 erg/cm2 , which is sufficient for a soft underlayer (SUL) in perpendicular magnetic recording media that are used in a hard disk drive, and the multilayers will be an alternative to the Co/Ru/Co
antiferromagnetically coupled system. From the viewpoint of practical thin-film fabrication, sputteringhas many advantages over vacuum deposition. As the first step, we have prepared epitaxial Fe3−δ O4 films
by employing rf magnetron sputtering and have determined their degree of oxidation using Mössbauer
spectroscopy.
A conventional multi-target rf sputtering system (ULVAC Inc.) was used for the sample preparation
with a metallic iron target. The flow rates of sputtering gases were controlled at 30 sccm for Ar and at
1.5 sccm for the reactive gas, O2 . The film was grown on the MgO (100) single crystal substrate, andthe film thickness was about 460 Å. The single crystal growth was confirmed by RHEED observation
just after the deposition. Mössbauer measurements were carried out with standard conversion electronMössbauer Spectroscopy(CEMS) at room temperature. Hyperfine fields and isomer shifts were calibrated
via a standard α-Fe spectrum recorded at room temperature. Data were analyzed with a commercial leastsquares fitting program (MossWinn 3.0).
Figure 1 shows a CEMS spectrum of the Fe3−δ O4 film. The spectrum was fitted to a single hyperfine
subspectrum with a hyperfine field of 487 kOe and an isomer shift of 0.33 mm/s, which are attributed toFe3+ ions of γ-Fe2 O3 . It is noted that the spectrum was fairly symmetric about the center of the spectrum,
which implies a simple configuration of the spectrum. However, the hyperfine field strength was slightly
smaller than the previously reported value 499 kOe for a bulk-like material[4]. There may be room for
improvement in the degree of oxidization and/or the ordering of B site vacancies.
In the previous work, we fabricated γ-Fe2 O3 thin films using a reactive vapor deposition techniquewith O3 gas[2,3]. In the present work, we have fabricated γ-Fe2 O3 thin films with the reactive sputtering
technique without using a special gas such as O3 . Since this technique does not require a special gas, it is
1 present address: Itami works, Sumitomo Electric Industry Ltd.

18

Intensity (arb. units)

Fe3-δ O4 film

Velocity (mm/s)
Fig. 1. CEMS spectrum of an iron oxide thin film prepared by reactive sputtering. This spectrum wasfitted to a single magnetic subspectrum with the hyperfine field of 487 kOe. The solid line shows
the fitting result.

advantageous for growing spinel-type ferrite oxide thin films.

References[1] Yuri Suzuki: Annu. Rev. Mater. Res. 31 (2001) 265.
[2] Y. Yanagihara et al.: J. Appl. Phys. 101 (2007) 09D101.
[3] M. Minagawa et al.: Jpn. J. Appl. Phys. 49 (2010) 080216.
[4] E. Murad, in Iron in Soils and Clay Minerals, J. W. Stucki, B. A. Goodman, and U. Schwertmann,eds., Reidel, Dordrecht, (1987)

19

3.6

Mössbauer analysis of Mg-containing Fe3O4 nanoparticles for magnetic
hyperthermia

D. Isaka, M. Kishimoto, H. Yanagihara, E. Kita
Magnetic nanoparticles have attracted much attention because of their potential to generate heat inmagnetic hyperthermia and thermoablation for cancer therapy. The origin of magnetically generated heatfrom inductive mediators essentially depends on the size and magnetic properties of the particles.
Hysteresis loss is a dominant mechanism of heat generation for ferromagnetic and ferrimagnetic particles.
We have been studying ferromagnetic nanoparticles, especially cobalt-doped magnetite particles, as highheat generating materials for magnetic hyperthermia and thermoablation [1]. We must consider thebiocompatibility of magnetic materials for their practical use. The biocompatibility of other elements thaniron, cobalt in particular, must be carefully checked, even when they are used as dopants. Although cobalt
toxicity is not fully understood, preparing cobalt-free particles is beneficial for safety aspects. In thepresent study, we synthesized Mg-containing iron oxide particles.
Spinel-structured Mg-containing iron oxide nanoparticles, (Mg)Fe3O4, were synthesized bycoprecipitation and a hydrothermal process. We have labeled the various nanoparticle samples MTH0
through MTH6 corresponding to the increasing Mg content from 0 to 10.0 at% with respect to the total Fe
content: the 10 at% concentration corresponds to Mg0.33Fe2.67O4. Magnetization of dry powdered samples
was measured using a vibration sample magnetometer (VSM). Particle size and crystal structure wereobtained using X-ray diffraction (XRD). Mössbauer spectra were recorded at room temperature and werenumerically analyzed using commercially available fitting software, MössWinn 3.0.
The basic characteristics of the (Mg)Fe3O4 particles in the various samples are summarized in Table
1. The magnitude of the coercive forces peaked for the MTH1 sample and then decreased with increasing
Mg content for the other samples.
Table 1. Characteristics of (Mg)Fe3O4 particles.
Sampl
Mg content
DXRD
Hc
Ms
e
at%
(nm)
(Oe) (emu/g)
2.0

33

155

77

MTH2

3.2

24

136

70

MTH3

4.0

21

109

68

MTH4

6.0

18

71

63

MTH5

8.0

15

41

54

MTH6

10.0

14

40

51

(311)

2000

(511)

MTH1

3000

1000

0
20

30

40
2θ (deg)

(422)

85

(200)

141

(222)

41

Cu-Kα

(220)

0

Intensity (a.u)

MTH0

4000

50

Fig. 1. XRD profile for (Mg)Fe3O4 MTH2
particles with 3.2 at% Mg.

2060

Figure 2 shows the typical Mössbauer spectra for (Mg)Fe3O4 particles. The solid lines indicate thefitted results. For all synthesized particles, the spectra composed of two ferromagnetic subspectra, and an
additional broad peak is present in the spectra for the MTH5 and MTH6 samples. The magnetic
subspectrum with the higher hyperfine field (Hhp) is attributed to the Fe3+ ions in tetrahedral sites (A sites)
and the other sextet to the Fe2+ and Fe3+ ions in the octahedral sites (B sites). The subspectrum with thebroad linewidth observed for MTH5 and MTH6 was fitted to a doublet and was attributed to thesuperparamagnetism caused by relatively small particle volumes.
The Mg atom distribution can be estimated from the area ratios of the subspectra. Mg atoms tend tooccupy B sites in the thin Mg concentration region below Mg0.5Fe2.5O4 [2]. To determine the occupation,
Mössbauer analyses have been generally performed at 77 K or lower. As seen in Fig. 2, the higher
concentration Mg samples contain the superparamagnetic component because of the small particle sizes.
Therefore, low-temperature measurements arehighly desirable in this work compared toMTH2previous works.

Tetrahedral (A)Octahedral (B)
SPM

Intensity (a.u)

MTH4

Fig. 2. Mössbauer spectra recorded

MTH5

at room temperature for MTH2,
MTH4, MTH5, and MTH6. Solidlines indicate fitted results.
MTH6

-12

-8

-4

0

4

8

12

Velocity (mm/s)

The heating characteristics of the dry MTH2 and (Co)Fe3O4 samples, which had the same coercive

force (~140 Oe), were measured with an 120 kHz alternating magnetic field produced using ahigh-frequency magnetic field applicator with a field amplitude of H0 = 400 Oe. The specific loss power(SLP) of the nanoparticles was evaluated by assuming that the total heat capacity included those of themagnetic particles and the water suspension sample. The SLP was then calculated using ΔT/Δt. The SLPsof the (Mg)Fe3O4 and (Co)Fe3O4 particles were 51 and 42 W/g, respectively. The experimentally obtained
SLP was consistent with the estimated loss power represented by the minor loop.
References[1] E. Kita et al., J. Phys. D: Appl. Phys. 43 (2010) 474011.
[2] F. Nakagomi et al., J. Solid State Chem. 182 (2009) 2423.

21

4.
INTERDISCIPLINARY RESEARCH

4.1

Direct Characterization of Hydrogen Content in MLCC employing
Elastic Recoil Coincidence Spectrometry

K. Morita1, Y. Iwazaki1, H. Kishi1, D. Sekiba and T. Komatsubara
Introduction
Hydrogen location has been recognized to be associated with the insulation properties in perovskite
system. Recently the first principle calculation by Iwazaki et al. has revealed that hydrogen atoms could
be trapped at oxygen vacancy sites with negative ions, H− (effectively negative single-charge, H´,
according to the Kröger-Vink notation) when the electron carrier density in perovskite oxides isremarkably high [1]. The calculation explains the recent experimental results that the hydrogen doping
into Nb-doped or oxygen-deficient SrTiO3 single crystals could decrease their high conductivity [2, 3].
Thus, a possible hydrogen-incorporation during the heat treatment in forming gas can be considered to beof great concern for the fabrication of thin-film-functional-devices based on perovskite oxides [4].
Some of the perovskite oxide ceramics are used as dielectric materials for multilayer ceramic capacitors(MLCCs). Nevertheless, the influence of hydrogen incorporation on insulation properties for the MLCCs
has never been sufficiently elucidated. In particular, BaTiO3-based MLCCs with Ni internal electrodes(Ni-MLCCs) are fired in a reducing atmosphere consisting of H2, N2 and H2O to prevent the Ni electrodes
from oxidation. Since hydrogen in the atmosphere could be partly incorporated into the BaTiO3-based
ceramics during the firing, it becomes important to know hydrogen content in Ni-MLCCs in order toensure the insulation properties.
In this report, we show the characterized results of the hydrogen content in Ni-MLCCs employing elastic
recoil coincidence spectrometry (ERCS). It is concluded that the hydrogen content is negligibly small an 5
μm. Some of the as-fired MLCCs were then oxidized at 1000°C in a mildly oxidizing atmosphere (Po2 =30 Pa). Moreover, some of the as-fired and oxidized MLCCs were heat-treated (600°C, 1 hour) in forminggas with the intent for hydrogen to be doped into the MLCCs.
Electrical characterization: The temperature dependence of permittivity and dielectric dissipation factor(tanδ) of the MLCCs were measured at 1.0 kHz and 1.0 Vrms using an impedance analyzer (Model
4284A; Agilent, USA). The current-voltage (I-V) characteristics of the MLCCs were measured at 25°C
and 150°C using an ultra-high resistance meter (Model R8340; Advantest, Japan). The current-time (I-t)
characteristics under the dc-electric field of 20 V/μm were recorded at 150°C.
ERCS hydrogen analysis: Proton-proton ERCS was employed to measure hydrogen content in the MLCCs.
ERCS using proton beam is nondestructive as well as highly sensitive for the detection of hydrogen atoms[5]. Fig. 1 illustrates a typical geometry of the measurement system. In the ERCS system, the Ni-MLCC
was irradiated with a 20 MeV proton beam, and recoiled protons in the MLCC and forward-scattered
incident protons were simultaneously detected by two silicon surface-barrier detectors. In principle, two
directions of the elastically scattered particles with the same mass form 90° in non-relativistic kinematics.
Therefore, the two detectors were installed at ±45° with respect to the incident beam so that a recoiled
1)

General R&D Laboratories, Taiyo Yuden Co., Ltd.

23

proton by an incident proton can be exclusively detected as a
Mylar films

coincidence event with the detection of the forward-scattered incident
proton. The beam current and the beam size on the MLCCs wereincident beam

detectorrecoiled
proton
MLCC

45°

2

approximately 120 pA and 0.3×0.4 mm , respectively. The ERCS

45°

spectra were analyzed and the hydrogen content was estimated using

forward-scatteredprotonthe Mylar films as the chemical standard.

detector

Fig. 1: Geometry of a measurement
system for proton-proton ERCS.

Results and Discussion
Characterization of Electrical property: No measurable differenceswere observed on permittivity and dielectric dissipation factor (tanδ) over a wide temperature range
between as-fired and oxidized MLCCs, implying that the oxidation treatment did not influence on
ferroelectric domain motion of the BaTiO3-based ceramics. However, the I-V and I-t characteristics of
those MLCCs are remarkably affected by the oxidation treatment. The oxidized MLCC exhibited much
lower current than that of the as-fired MLCC. The current for the oxidized one kept stable for more than
10000 seconds, though, those for the as-fired one broke down as soon as the measurement started. These
results imply that the insulation properties can be attributed to oxygen vacancies generated during thefiring. In the firing process, when the BaTiO3-based ceramics were reduced, electrons as twice many as
oxygen vacancies could be introduced into the perovskite lattice as follows:
OoX

→

Vo••

+ 2e´

(1)

where OoX and Vo•• represent an oxygen atom in the lattice and an oxygen vacancy with the effectively
positive double-charge, respectively. The oxidizing treatment decreases the amount of both oxygen
vacancies and electrons, resulting in the decrease of leakage current. Furthermore, the decrease in oxygen
vacancies provides MLCCs with longer lifetime since electro-migrations of oxygen vacancies are
predominant cause for insulation-degradation with time for MLCCs [6, 7]. However, if there is aremarkable change in hydrogen content before and after the oxidation treatment, the contributions ofhydrogen to the insulation properties should be considered. When hydrogen atoms are incorporated into
the BaTiO3-based ceramics without the influence of oxygen vacancies, electrons can be generated asfollows:
H2

→

2Hi•

+

2e´

(2)

where Hi• represent an interstitial hydrogen atom with the effectively positive single-charge in perovskite
lattice. Therefore, we need to know hydrogen content to pursue the exact cause of leakage current in
Ni-MLCCs.

24

ERCS measurements: Mylar films with1400

standard samples. Fig. 2 shows proton counts

1200

as a function of channels, which corresponds

1000

to the sum energy of two protons detected, forthe as-fired MLCC between the Mylar films.

Countsknown hydrogen content were employed as

When a proton is scattered by another proton,

Exit side
Mylar

800
Incident side
Mylar

600

the recoil energy becomes a half of the400

incident energy. Then the recoiled proton

200

suffers larger energy loss because the stopping

0

MLCC

0

power increases by ~ 1.7 times for thehalf-energy protons. Since the sum of energy

200

400

600
800
Channels

1000

1200

Fig. 2: ERCS spectrum for as-fired MLCC
between two Mylar films. The signals
around 350 Ch and 750 Ch are from Mylar
films at the incident side and at the exit
side, respectively.

loss of recoiled protons is proportional to thedepth measured from the exit side, the ERCS
spectrum of Fig. 2 indicates the depth profile
of hydrogen content. The signals at 350
Ch and 750 Ch are from the Mylar filmsof the incident and the exit sides,
respectively, as illustrated in Fig. 1. The
detection of protons from the Mylar
film of the incident side shows thatrecoiled

protonscanbedetectedthrough the MLCC with 0.35 mm
thickness. The hydrogen content inside
the MLCCs was estimated by using theyields from the Mylar films as thecalibration.
The ERCS spectra of the as-fired
MLCC and the oxidized MLCC without

Fig. 3: ERCS spectra for (a) the as-fired and (b)the oxidized MLCCs. ERCS spectra for (c) the
fired and (d) MLCCs after the heat treatment informing gas.

Mylar films are shown in Fig. 3 (a) and (b), respectively. The signals around 350 Ch and 750 Ch are fromthe contaminations on the MLCC surfaces. The signals from MLCC, which correspond to the region
shown in Fig. 2, are very small compared to those from the surface contamination. The hydrogen contents
estimated are 2.3 ± 0.1 ppm for the as-fired MLCC and 2.9 ± 0.1 ppm for the oxidized MLCC. It should
be noted that the small amount of the yield is close to the measuring limit. In the same manner, wemeasured hydrogen content of the MLCCs via heat treatment in forming gas, and obtained ERCS spectra
shown in Fig. 3 (c) and (d). The estimated values from these spectra are 2.8 ± 0.1 ppm for the as-fired
MLCC and 3.2 ± 0.1 ppm for the oxidized MLCC. These results indicate that the hydrogen contents in
Ni-MLCCs are maintained to be very small values close to the measurement limit irrespective of the25various atmospheres used in our experiments.
The estimated hydrogen content can be thought to be much smaller than the amount of oxygen vacancies
in Ni-MLCCs. Whereas, G. Y. Yang et al. have revealed that the oxygen vacancies can be locallyaccumulated near the grain boundaries and cathodes in a concentration of ~ 10% for the
resistance-degraded Ni-MLCC by dc electric field at elevated temperature [8]. Therefore, one canconclude that the influence of hydrogen on the insulation properties of Ni-MLCCs is negligible. On theother hand, several reports point out that hydrogen atoms incorporated into perovskite oxide ceramics, andthe water-electrolysis can cause the insulation-degradation [9-11]. Thus the research on this viewpointshould be required to elucidate the role of hydrogen in Ni-MLCCs.
Acknowledgements
The present study was conducted under the support of the project ‘Open Advanced Facilities Initiativefor Innovation (Strategic Use by Industry)’ of Ministry of Education, Culture, Sports, Science andTechnology (MEXT), Japan.

References[1] Y. Iwazaki, T. Suzuki, and S. Tsuneyuki, J. Appl. Phys. 108 (2010) 083705.
[2] J. Y. Dai, W. P. Chen, G. K. H. Pang, P. F. Lee, H. K. Lam, W. B. Wu, H. L. W. Chan, and C. L. Choy,Appl. Phys. Lett. 82 (2003) 3296-3298.
[3] B. Jalan, R. Engel-Herbert, T. E. Mates, and S. Stemmera, Appl. Phys. Lett. 93 (2008) 052907.
[4] K. Morito, T. Suzuki, Y. Mizuno, I. Sakaguchi, N. Ohashi, and H. Haneda, Key Eng. Mater. 388 (2009)167-170.
[5] T. Komatsubara, K. Sasa, K. Okumoto, S. Ishii, Y. Yamamoto, K. Satou, K. Furuno, and M. Kurosawa,
Nucl. Instr. and Meth. in Phys. Res. B 251 (2006) 237-245.
[6] H. Chazono and H. Kishi, Jpn. J. Appl. Phys. 40 (2001) 5624-5629.
[7] K. Morita, Y. Mizuno, H. Chazono, and H. Kishi, Jpn. J. Appl. Phys. 41 (2002) 6957-6961.
[8] G. Y. Yang, E. C. Dickey, and C. A. Randall, J. Appl. Phys. 96 (2004) 7500-7508.
[9] W. P. Chen, X. P. Jiang, Y. Wang, Z. Peng, and H. L. W. Chan, J. Am. Ceram. Soc. 86 (2003) 735-37.
[10] W. P. Chen, L. T. Li, Y. Wang, and Z. L. Gui, J. Mater. Res. 13 (1998) 1110-12.
[11] M. Widerøe, R. Waser, and T. Norby, Solid State Ionics 177 (2006) 1469-1476.

26

5.

LIST OF PUBLICATIONS

5.1 Journals
NUCLEAR PHYSICS
1. T. Yamaguchi, K. Tanaka,T. Suzuki, A. Ozawa, T. Ohtsubo, T. Aiba, N. Aoi, H. Baba, M. Fukuda,Y.
Hashizume, K. Inafuku, N. Iwasa, T. Izumikawa, K. Kobayashi, M. Komuro, Y. Kondo, T. Kubo, M.
Kurokawa, T. Matsuyama, S. Michimasa, T. Motobayashi, T. Nakabayashi, S. Nakajima, T. Nakamura,
H. Sakurai, R. Shinoda, M. Shinohara, H. Suzuki, M. Takechi, E. Takeshita, S. Takeuchi, Y. Togano, K.
Yamada, T. Yasuno, M. Yoshitake, Nuclear reactions of 19,20C on a liquid hydrogen target measured
with the superconducting TOF spectrometer, Nuclear Physics A 864, 1-37 (2011).
2. Nozomi Sato, Hiromitsu Haba, Takatoshi Ichikawa, Daiya Kaji, Yuki Kudou, Kouji, Morimoto,
Kosuke Morita, Kazutaka Ozeki, Takayuki Sumita, Akira Yoneda, Eiji Ideguchi, Hiroyuki Koura,
Akira Ozawa, Tsutomu Shinozuka, Takayuki Yamaguchi, and Atsushi Yoshida, Production and Decay
Properties of 264Hs and 265Hs, J. Phys. Soc. Jpn., Vol.80, 094201 (2011).
3. K. Minamisono, T. Nagatomo, K. Matsuta, C. D. P. Levy, Y. Tagishi, M. Ogura, M. Yamaguchi, H. Ota,
J. A. Behr, K. P. Jackson, A. Ozawa, M. Fukuda, T. Sumikama, H. Fujiwara, T. Iwakoshi, R.
Matsumiya, M. Mihara, A. Chiba, Y. Hashizume, T. Yasuno, and T. Minamisono, Low-energy test of
second-class current in β decays of spin-aligned 20F and 20Na, Phys. Rev. C 84, 055501 (2011).
4. A. Ozawa, Y. Hashizume, Y. Aoki, K. Tanaka, T. Aiba, N. Aoi, H. Baba, B. A. Brown, M. Fukuda, K.
Inafuku, N. Iwasa, T. Izumikawa, K. Kobayashi, M. Komuro, Y. Kondo, T. Kubo, M. Kurokawa, T.
Matsuyama, S. Michimasa, T. Motobayashi, T. Nakabayashi, S. Nakajima, T. Nakamura, T. Ohtsubo,
H. Sakurai, R. Shinoda, M. Shinohara, H. Suzuki, T. Suzuki, M. Takechi, E. Takeshita, S. Takeuchi, Y.
Togano, K. Yamada, T. Yamaguchi, T. Yasuno, and M. Yoshitake, One- and two-neutron removal
reactions from 19,20C with a proton target, Phys. Rev. C 84, 064315 (2011).

The publications listed here are those released in the fiscal year 2011 by all the workers listed on p.39.

27

5. M. Takechi, T. Ohtsubo, M. Fukuda, D. Nishimura, T. Kuboki, T. Suzuki, T. Yamaguchi, A. Ozawa, T.
Moriguchi, H. Ooishi, D. Nagae, H. Suzuki, S. Suzuki, T. Izumikawa, T. Sumikama, M. Ishihara, H.
Geissel, N. Aoi, Rui-Jiu Chen, De-Qing Fang, N. Fukuda, I. Hachiuma, N. Inabe, Y. Ishibashi, Y. Ito,
D. Kameda, T. Kubo, K. Kusaka, M. Lantz, Yu-Gang Ma, K. Matsuta, M. Mihara, Y. Miyashita, S.
Momota, K. Namihira, M. Nagashima, Y. Ohkuma, T. Ohnishi, M. Ohtake, K. Ogawa, H. Sakurai, Y.
Shimbara, T. Suda, H. Takeda, S. Takeuchi, K. Tanaka, R. Watanabe, M. Winkler, Y. Yanagisawa, Y.
Yasuda, K. Yoshinaga, A. Yoshida, K. Yoshida, Interaction cross sections for Ne isotopes towards theisland of inversion and halo structures of 29Ne and 31Ne, Physics Letters B 707, 357-361 (2012).

MATERIALS AND CLUSTER SCIENCE
6. Takuro Yoshikawa, Yasushi Kanke, Hideto Yanagihara, Eiji Kita, Yorihiko Tsunoda, Kiiti Siratori, Kay
Kohn, Mössbauer study on the antiferromagnetic FeO synthesized under high pressure, Hyperfine
Interact., 205 (2012)135-138
7. Hideto Yanagihara, K. Uwabo, Makoto Minagawa, Eiji Kita, and Nobuyuki Horita, Perpendicularmagnetic anisotropy in CoFe2O4(001) films epitaxially grown on MgO(001), J. Appl. Phys., 109(2011) 07C122
8. Masataka Ohkubo, Shigetomo Shiki, Masahiro Ukibe, Shigeo Tomita, Shigeo Hayakawa, “Direct
mass analysis of neutral molecules by superconductivity”, Int. J. Mass Spectrom. 299, 94-101, (2011)
9. K. Harada, K. S. Makabe, H. Akinaga, and T. Suemasu, “Room temperature magnetoresistance inFe3Si/CaF2/Fe3Si MTJ epitaxially grown on Si(111)”, J. Phys. Conference Series 266 , 012088 (2011)(5 pages).
10. K. Harada, K. S. Makabe, H. Akinaga, and T. Suemasu, “Magnetoresistance characteristics of
Fe3Si/CaF2/Fe3Si heterostructures grown on Si(111) by molecular beam epitaxy”, Physics Procedia 11,
15-18 (2011).
11. S. Yin, M. Takahashi, R. Miida, H. Iwasaki and Ken-ichi Ohshima, “X-ray Diffraction Study of theOrdered Structures and Phase Relation in Pd-Mn Alloy System”, Materials Transactions 52, 374 - 379(2011).
12. A. Uedono, S. Ishibashi, K. Tenjinbayashi, T. Tsutsui, K. Nakahara, D. Takamizu, and S. F.

Chichibu, “Defect characterization in Mg-doped GaN studied using a monoenergetic positron
beam,” J. Appl. Phys. 111, 014508(1-6) (2012).

28

13. A. Uedono, K. Tenjinbayashi, T. Tsutsui, Y. Shimahara, H. Miyake, K. Hiramatsu, N.
Oshima, R. Suzuki, and S. Ishibashi, “Native cation vacancies in Si-doped AlGaN studied bymonoenergetic positron beams,” J. Appl. Phys. 111, 013512(1-5) (2012).
14. M. Sometani, R. Hasunuma, M. Ogino, H. Kuribayashi, Y. Sugahara, A. Uedono, and K.
Yamabe, “Variation of chemical vapor deposited SiO2 density due to generation andshrinkage of open space during thermal annealing,” Jpn. J. Appl. Phys. 51, 021101(1-3)(2012).
15. A. S. Hamid, A. Uedono, Zs. Major, T. D. Haynes, J. Laverock, M. A. Alam, and S. B.
Dugdale, D. Fort, “Electronic structure and Fermi surface of the weak ferromagnet Ni3Al,”
Phys. Rev. B 84, 235107 (2011).
16. Y. Oka, A. Uedono, K. Goto, Y. Hirose, M. Matsuura, M. Fujisawa, and K. Asai,“Structure-modification model of progen-based porous SiOC film with ultraviolet curing,”
Jpn. J. Appl. Phys. 50, 05EB06(1-5) (2011).
17. S. F. Chichibu, K. Hazu, T. Onuma, and A. Uedono, “Collateral evidence for an excellent
radiative performance of AlxGa1−xN alloy films of high AlN fractions,” Appl. Phys. Lett. 99,
051902(1-3) (2011).
18. M. M. Islam, A. Uedono, S. Ishibashi, K. Tenjinbayashi, T. Sakurai, A. Yamada, S. Ishizuka,
K. Matsubara, S. Niki, and K. Akimoto, “Impact of Cu/III ratio on the near-surface defects inpolycrystalline CuGaSe2 thin films,” Appl. Phys. Lett. 98, 112105(1-3) (2011).
19. N. Oshima, B. E. O’Rourke, R. Kuroda, R. Suzuki, H. Watanabe, S. Kubota, K. Tenjinbayashi,
A. Uedono, and N. Hayashizaki, “Slow positron beam apparatus for surface and subsurface
analysis of samples in air,” Appl. Phys. Express 4, 066701(1-3) (2011).
20. E. Mume, D. E. Lynch, A. Uedono, S. V. Smith, “Investigating the binding properties ofporous drug delivery systems using nuclear sensors (radiotracers) and positron annihilation
lifetime spectroscopy-Predicting conditions for optimum performance,” Dalton Transactions
40, 6278-6288 (2011).
21. A. Uedono, S. Ishibashi, S.F. Chichibu and K. Akimoto, “Point defects in GaN and relatedgroup-III nitrides studied by means of positron annihilation,” Gallium Nitride Materials andDevices VI, edited by J.-I. Chyi, Y. Nanishi, H. Morkoç, J. Piprek, E. Yoon, Proc. of SPIE Vol.
7939, 79390I(1-10) (2011).

29

22. E. Mume, A. Uedono, G. Mizunaga, D. E. Lynch, and S. V. Smith, “The role of positronannihilation lifetime studies and nuclear sensors for characterizing porous materials,” 12th
International Workshop on Slow Positron Beam Techniques (SLOPOS12), Journal of Physics:
Conference Series 262, 012040(1-4) (2011).
23. N. Oshima, R. Suzuki, T. Ohdaira, A. Kinomura, S. Kubota, H. Watanabe, K. Tenjinbayashi,
A. Uedono, and M. Fujinami, “Imaging of the distribution of average positron lifetimes byusing a positron probe microanalyzer,” 12th International Workshop on Slow Positron BeamTechniques (SLOPOS12), Journal of Physics: Conference Series 262, 012044(1-4) (2011).
24. S. Sellaiyan, S. V. Smith, A. E. Hughes, A. Miller, D. R. Jenkins, and A. Uedono,“Understanding the effect of nanoporosity on optimizing the performance of self-healingmaterials for anti-corrosion applications,” 12th International Workshop on Slow Positron
Beam Techniques (SLOPOS12), Journal of Physics: Conference Series 262, 012054(1-4)(2011).
25. A. Uedono, S. Ishibashi, N. Oshima, T. Ohdaira, and R. Suzuki, “Application of positronannihilation technique to front and backend processes for modern LSI devices,” 12th
International Workshop on Slow Positron Beam Techniques (SLOPOS12), Journal of Physics:
Conference Series 262, 012061(1-4) (2011).
26. A. Uedono, S. Ishibashi, S. F. Chichibu, and K. Akimoto, “Point defects in GaN and relatedgroup-III nitrides studied by means of positron annihilation,” Gallium Nitride Materials andDevices VI, ed. J.-I. Chyi, Y. Nanishi, H. Morkoc, and J. Piprek, E. Yoon, Proc. of SPIE 7939,
79390I (1-10) (2011).
27. E. Mume, A. Uedono, G. Mizunaga, D. L. Lynch, and S. V. Smith, “The role of positronannihilation lifetime studies and nuclear sensors for characterizing porous materials,” J.
Phys.: Conf. Ser. 262, 012040(1-4) (2011).
28. N. Oshima, R. Suzuki, T. Ohdaira, A. Kinomura, S. Kubota, H. Watanabe, K. Tenjinbayashi,
A. Uedono, and M. Fujinami, “Imaging of the distribution of average positron lifetimes byusing a positron probe microanalyzer,” J. Phys.: Conf. Ser. 262, 012044(1-4) (2011).
29. S. Sellaiyan, S. V. Smith, A. E. Hughes, A. Miller, D. R. Jenkins, and A. Uedono,“Understanding the effect of nanoporosity on optimizing the performance of self-healingmaterials for anti-corrosion applications,” J. Phys.: Conf. Ser. 262, 012054(1-4) (2011).

30

30. A. Uedono, S. Ishibashi, N. Oshima, T. Ohdaira, and R. Suzuki, “Application of positronannihilation technique to front and backend processes for modern LSI devices,” J. Phys.:Conf. Ser. 262, 012061(1-4) (2011).

ACCELERATOR MASS SPECTROMETRY
31. S. Merchel, W. Bremser, V. Alfimov, M. Arnold1, G. Aumaître, L. Benedetti, D. L. Bourlès, M. Caffee,
L. K. Fifield, R. C. Finkel, S. P. H. T. Freeman, M. Martschini, Y. Matsushi1, D. H. Rood, K. Sasa, P.
Steier, T. Takahashi, M. Tamari, S. G. Tims, Y. Tosaki, K. M. Wilcken and S. Xu, Ultra-trace analysis
of 36Cl by accelerator mass spectrometry: an interlaboratory study, Analytical and Bioanalytical
Chemistry, 400, (2011), 3125-3132. doi:10.1007/s00216-011-4979-2.
32. Norikazu Kinoshita, Keisuke Sueki, Kimikazu Sasa, Jun-ichi Kitagawa, Satoshi Ikarashi, Tomohiro
Nishimura, Ying-Shee Wong, Yukihiko Satou, Koji Handa, Tsutomu Takahashi, Masanori Sato,
Takeyasu Yamagata, First assessment of individual radionuclides distributions from the Fukushima
nuclear accident covering central-east Japan, Proceedings of the National Academy of Sciences(PNAS), (2011). doi:10.1073/pnas.1111724108.
33. Yuki Tosaki, Norio Tase, Kimikazu Sasa, Tsutomu Takahashi, Yasuo Nagashima, Measurement of 36Cl
deposition flux in central Japan: Natural background level and its seasonal variability, Journal ofEnvironmental Radioactivity, Journal of environmental radioactivity, 106, 73-80 (2012).
34. N. Kinoshita, M. Paul, Y. Kashiv, P. Collon, C. M. Deibel, B. DiGiovine, J. P. Greene, D. J. Henderson,
C. L. Jiang, S. T. Marley, T. Nakanishi, R. C. Pardo, K. E. Rehm, D. Robertson, R. Scott, C. Schmitt,
X. D. Tang, R. Vondrasek, A. Yokoyama, A Shorter 146Sm Half-Life Measured and Implications for146

Sm-142Nd Chronology in the Solar System, Science, 30 March (2012), Vol. 335 no. 6076 pp.

1614-1617.

INTERDISCIPLINARY RESEARCH
35. K. Nomura, Y. Ohki, M. Fujimaki, X. Wang, K. Awazu, T. Komatsubara, A study of the critical factor
determining the size of etched latent tracks formed on SiO2 glass by swift-Cl-ion irradiation, Nuclear
Instruments and Methods in Physical Research B 272, 1-4 (2012).

31

5.2 International conferences
1. Akira Ozawa, 'Overview of Rare-RI Ring and mass measurements', RIBF-ULIC-Symposium-009'Physics of Rare-RI Ring', Nov. 10-12, (2011), Wako, RIKEN Nishina Center, Japan, (Invited talk)
2. Daisuke Nagae, 'TOF detector for RIKEN Rare-RI Ring', RIBF-ULIC-Symposium-009 'Physics ofRare-RI Ring', Nov. 10-12, (2011), Wako, RIKEN Nishina Center, Japan, (Invited talk)3. Yuki Tosaki, Norio Tase, Kimikazu Sasa, Tsutomu Takahash and Yasuo Nagashima, Estimation of
Groundwater Age Using the 36Cl Bomb Pulse: a Case Study in the Mt. Fuji Area, Central Japan,
AOGS 2011, Aug. 08-12 (2011). (Invited talk)
4. A. Uedono, S. Ishibashi, N. Oshima, T. Ohdaira, and R. Suzuki, “Defects in GaN and group-III
nitrides studied by positron annihilation technique,” The international Workshop on Positron Studies
of Defects 2011, Delft University of Technology, Delft, Netherlands, 28 August, (2011). (Invited talk)
5. A. Uedono,
beams

Detection of point defects in semiconductor device materials by monoenergetic positron, IMEC Kapeldreef 75, B-3001 Leuven, Belgium, 2 Sept., (2011). (Invited talk)

6. A. Uedono,

Characterization of semiconductor device materials by means of positron annihilation

technique, Australian Nuclear Science and Technology Organization (ANSTO), Bragg Institute

Seminar, Kirrawee DC NSW 2232, Australia, 21 July, (2011). (Invited talk)
7. Peter Schury, 'MRTOF at RIKEN', RIBF-ULIC-Symposium-009 'Physics of Rare-RI Ring', Nov.
10-12, (2011), Wako, RIKEN Nishina Center, Japan
8. Takuro Yoshikawa, Yasushi Kanke, Hideto Yanagihara, Eiji Kita, Yorihiko Tsunoda, Kiiti Siratori, Kay
Kohn, “Mössbauer study on the antiferromagnetic FeO synthesized under high pressure”, International
Conference on the Applications of the Mössbauer Effect, 25-30 September 2011, Kobe
9. K. Sasa, S. Ishii, and M. Kurosawa, Micro-PIXE system for geosciences applications at the Tsukuba 1
MV Tandetron accelerator facility, the 7th International Symposium on Bio-PIXE (BioPIXE7), Tohoku
University, Sendai, Japan, 30 Oct. - 4 Nov. (2011).
10. Kimikazu Sasa, Tsutomu Takahashi and Keisuke Sueki, New AMS project at the University ofTsukuba, The 4th East Asia AMS Symposium, 16-18 December, (2011), Takeda Hall, The Universityof Tokyo.

32

11. Yuki Matsushi, Kimikazu Sasa, Kazuna Kurosumi, Tsutomu Takahashi, Kazuho Horiuchi, Yuki Tosaki,
Keisuke Sueki, Hiroyuki Matsuzaki, Motohiro Hirabayashi and Hideaki Motoyama, Long-term 36Cl
depositional flux recorded in the Dome Fuji ice core, Antarctica: a possible link to climate change in
mid latitudes during the last two deglaciations, The 4th East Asia AMS Symposium, 16-18 December,(2011), Takeda Hall, The University of Tokyo.
12. Keisuke Sueki, Jun-ichi Kitagawa, Takahiro Amano, Michiko Tamari, Kimikazu Sasa, Tsutomu
Takahashi, Norikazu Kinoshita, Hangtao Shen, Yuki Tosakii, Yuki Matsushi and Matuzaki
Distributions of radionuclides 36Cl and 129I in surface soils, The 4th East Asia AMS Symposium, 16-18
December, (2011), Takeda Hall, The University of Tokyo.
13. Yuki Tosaki, Norio Tase, Kimikazu Sasa, Tsutomu Takahashi, Sonia Gmati and Sayako Ueno,
Characterization of groundwater chemistry and ages in volcanic aquifers of the southern foot of Mt.
Fuji, central Japan, The 4th East Asia AMS Symposium, 16-18 December, (2011), Takeda Hall, The
University of Tokyo.
14. Shigeo Tomita, “Correlation between consumption of SO2 and Nucleation Rate in N2/H2O/SO2 by
Irradiation of 20 MeV protons”, The 2nd Nagoya Workshop on the Relationship between Solar
Activity and Climate Changes, Jan. 16-17, (2012), Nagoya, Japan
15. M. Takahashi, H. Kato, K. Ohshima, Y. Noda, T. Shishido, “Atomic order and Magnetism in
Pt1−xMnx(x = 0.11 ~ 0.14) “, 1st Asia-Oceania Conference on Neutron Scattering (1st AOCNS), Nov.
20-24, (2011), Tsukuba EPOCAL, Tsukuba, Japan
16. K. Harada, Room temperature magnetoresistance in Fe3Si/CaF2/Fe3Si MTJ epitaxially grown on
Si(111), 2nd International Symposium on Advanced Magnetic Materials and Applications, July 12-16,(2010), Sendai, Japan
17. K. Harada, Magnetoresistance characteristics of Fe3Si/CaF2/Fe3Si heterostructures grown on Si(111)by molecular beam epitaxy, APAC-Silicide 2010, July 24-26, (2010), Tsukuba EPOCAL, Tsukuba,
Japan

33

6.

THESES

Ph. D. theses
Tetsuaki MORIGUCHI

Density distributions for two neutron halo nuclei 8 Li and 14Be deduced by thereaction cross section measurements

Suguru SATO

Analysis of coercive force mechanisms in soft and hard magnetic
nano-materials

Master’s theses
Yasushi ABE

Developments of time-of-flight detector for RI beams using secondary
electron emission from carbon foil

Kimitake OKUMURA

Measurements of production cross sections for Al isotopes from 48Ca beam

Shota FUKUOKA

Developments of lumped parameter type kicker magnet with impedance
matching for J-PARC main ring

Sosuke NAKAMURA

Developments high efficiency ESI using RF carpet for mass calibration

Hideomi TANIKAWA

Correlation between Droplet Yield and the Consumption of SO2 in the
Nuclation process by Irradiation of 20MeV protons in N2/H2O/SO2

Shinya TAMURA

Measurements of secondary electrons emitted by Cn+ using MCP

Kazunori HARADA

Investigation of density of states of Fe3Si and fabrication of magnetic tunnel
junction devices

Kazuna KUROSUMI

Analysis of cosmogenic 36Cl from the last deglaciation to Holocene in theDome Fuji ice core , Antarctica.

Keisuke ODA

Growth of rare earth doped Gallium Nitride and its characterization

Keisuke KURITA

Development of photoemission spectroscopy apparatus for electronic
structure investigation of H/Pd(110)

Yohei NARITA

Hydrogen uptake process into Mg multilayer observed by nuclear reaction
analysis34

Undergraduate theses
Syunsuke OKADA

Design of septum magnet of Rare-RI Ring

Yuta SAITO

Beam-optics for injection line in Rare-RI Ring

Momo MUKAIDSMC simulation of rarefied gas flow inside Cluster-I]

Takahiro ONISHI

Study of nucleosynthesis by means of scandium 45 + proton reaction

Yoko SHIINA

Coincidence measurements between transmitted ions and secondary electron
yieldsIsao HARAYAMA

Correlation between Droplet Yield and the Consumption of SO2 in the
Nucleation process by corona discharge in N2/H2O/SO2

Katsuya YAMAZAKI

Developmet of TOF Mass Spectrometer

Kenta CHITO

Development of high-resolution RBS for observation of graphite intercaration

Shunya HARADA

Development of ambient-NRA for observation of hydrogen uptake process
into Mg thin film

35

7.

SEMINARS

2011
April 15Comparison of elliptic flow among various Identified hadrons and understanding of radialand elliptic expansion in 200GeV Au+Au at RHIC-PHENIX, Yoshimasa Ikeda (Universityof Tsukuba)2012
Jan 23Development of time-of-flight detector for RI-beam utilizing secondary electron emission
from carbon foil, Yasushi Abe (University of Tsukuba)
Measurements of production cross-section for Al isotopes by a 48Ca beam, Kimitake
Okumura (University of Tsukuba)
Study of the multiplicity dependence of the jet energy balance in p+p collisions at √s = 7
TeV by the LHC-ALICE experiment, Shintaro Kubota (University of Tsukuba)

Jan 26

Study of multi-particle correlations in Pb+Pb collisions at √sNN = 2.76TeV by the
LHC-ALICE experiment, Yuki Kondo (University of Tsukuba)
Study of Higher Harmonic Azimuthal anisotropy in Pb+Pb collisions at √sNN = 2.76TeV by
the LHC-ALICE experiment, Hitoshi Nakazato (University of Tsukuba)
Development of an efficient ESI using RF carpet for mass calibration, Sosuke Nakamura(University of Tsukuba)

Jan 30Study of identified particle higher harmonic azimuthal anisotropyin Au+Au collisions at√sNN = 200GeV by the RHIC-PHENIX experiment, Sanshiro Mizuno (University ofTsukuba)
Developments for impedance matching and lumped-constant kicker magnet in J-PARC
Main Ring, Shota Fukuoka (University of Tsukuba)

March 7A new measurement of the astrophysical 8Li(α,n)11B reaction with the GEM-MSTPC,
Kanako Yamaguchi (University of Tsukuba)

36

8.

SYMPOSIUM=== A debrief meeting of the Pre-Strategic Initiatives ===A new dimension of the multi-tandem accelerator facility
at the University of Tsukuba
29 March 2012
Laboratory of Advanced Research B 0110

1. Openning : E. Kita (University of Tsukuba)
2. Disaster situation of the multi-tandem accelerator facility at the University of Tsukuba and overview
of the update scheme for the new tandem accelerator : K. Sasa (University of Tsukuba)
3. Studies of 12C+4He → 16O+γ reaction and triple-nuclei-reaction-mechanics in Kyushu University : K.
Sagara (Kyushu University )4. Nucleosynthesis associated with 12C(α,γ)16O reaction : H.Makii (JAEA)
5. Studies of magnetic moments with polarized unstable nuclei and its applications for material science :K. Matsuta (Osaka University)
6. Studies of Nucleosysthesis by using proton pulsed beam : T. Hayakawa (JAEA)
7. Nuclear astrophysics with 1MV Tandetron accelerator : T. Komatsubara (University of Tsukuba)
8. Overview of accelerator mass spectrometry with multi-nuclide : H.Matsuzaki (The University ofTokyo)
9. Archaeological studies for west Asian civilization – Anticipation for 14C dating – : A. Tsuneki(University of Tsukuba)
10. Perspectives of accelerator mass spectrometry for geological science : K.Horiuchi (Hirosaki
University)
11. New methodology of dating with accelerator mass spectroscopy : H.Matsumura (KEK)
12. Research activities of AMS study for environmental science in the University of Tsukuba : K. Sueki(University of Tsukuba)37

13. Elemental analysis on surface and/or interface of materials by using high resolution RBS : K. Kimura(Kyoto University)
14. Industrial applications of nanoscale pore produced by heavy-ion-irradiation-technique : M. Fujimaki(National Institute of Advanced Industrial Science and Technology (AIST))
15. Industrial uses and ion-beam applications in RIBF at RIKEN : T. Kanbara (RIKEN)
16. PIXE analysis for geological science : M. Kurosawa (University of Tsukuba)
17. Electron excitation process induced by fast ion-cluster irradiation : S. Tomita (University of Tsukuba)
18. Device developments by use of electron-positron-annihilation γ−ray analysis : A.Uedono (Universityof Tsukuba)
19. Closing remarks: A. Ozawa (University of Tsukuba)

38

9.

LIST OF PERSONNEL

Tandem Accelerator Complex
E. Kita

Director, Professor

K. Sasa

Associate Professor

T. Komatsubara

Assistant Professor

D. Sekiba

Assistant Professor

H. KimuraComputer Engineer

H. Oshima

Electric Engineer

Y. Tajima

Mechanical Engineer

S. Ishii

Mechanical Engineer

T. Takahashi

Electric Engineer

Y. YamatoElectric Engineer

N. Kinoshita

Research Fellow

Y. Tagishi

Research Supporter

K. Iitake

Administrative Stuff

N. YamadaAdministrative Stuff

S. AbeAdministrative Stuff

Research Members1
Inst. of Physics
I. AraiT. Komatsubara

K. Sasa

P. Schury

D. Nagae

A. Ozawa

Inst. of Applied Physics
K. Akimoto

S. Aoki

E. Kita

M. Minagawa

D. Sekiba

T. Suemasu

S. Tomita

A. Uedono

H. Yanagihara
Inst. of Materials Science
T. Kondo

M. Takahashi

Inst. of Engineering Mechanics and Systems
K. Matsuuchi
1

The “research members” include the authors and coauthors within 5 years back from this fiscal year, as well as themembers of research projects running at UTTAC.

39

Inst. of Geoscience
M. Kurosawa
Inst. of Chemistry
K. Sueki
Staff of Open Advanced Facilities Initiative
H. KudoH. Naramoto

M. Matsumura

H. Muromachi

H. ShenS. Yamazaki

T. Moriguchi

Graduate students
Doctoral Programs of Pure and Applied Science
Y. Ishibashi

K. ItoY. ItoS. SatoK. Suzuki

K. Yamaguchi

Master’s Programs of Pure and Applied Science
Y. AbeS. Fukuoka

S. Funada

D. Isaka

M. IuraY. Kiguchi

J. Kitagawa

K. Kurita

H. MitaT. Mizunaga

S. Nakamura

Y. Narita

R. Nishikiori

T. Niwa

K. OdaK. Okumura

N. Takemoto

S. Tamura

H. Tanikawa

K. Tenjinbayashi

T. Tsutsui

M. UehiraY. Yamashita

S. Yoshimatsu

T. Yuasa

Y. Watahiki

K. Kurozumi

Y. SatoY. Wong

K. Chito

S. Harada

I. Harayama

S. Kimura

A. Mori

M. MukaiS. Okada

T. Onishi

Y. SaitoT. Sanai

S. Shohata

Y. Shiina

K. Yamazaki

T. Watanabe

Master’s Programs of Life and Environmental Science
M. Ishikawa
Undergraduates

40

Scientific Gutests and Fellows
K. Awazu

National Institute of Advanced Industrial Science and Technology (AIST)

M. Fujimaki

National Institute of Advanced Industrial Science and Technology (AIST)

Y. Tosaki

National Institute of Advanced Industrial Science and Technology (AIST)

T. Hayakawa

Japan Atomic Energy Agency (JAEA)

T. Shizuma

Japan Atomic Energy Agency (JAEA)

S. KubonoCenter for Nuclear Study, Univ. of Tokyo (CNS)

A. SatoOsaka Univ.

A. Yamamoto

High Energy Accelerator Research Organization (KEK)

T. AdachiHigh Energy Accelerator Research Organization (KEK)

M. YoshidaHigh Energy Accelerator Research Organization (KEK)

N. Kawamura

High Energy Accelerator Research Organization (KEK)K. Shimomura

High Energy Accelerator Research Organization (KEK)

P. Strasser

High Energy Accelerator Research Organization (KEK)

T. Nakamoto

High Energy Accelerator Research Organization (KEK)

M. IioHigh Energy Accelerator Research Organization (KEK)K. YoshimuraHigh Energy Accelerator Research Organization (KEK)41