UTTAC-76, 2007
ISSN 1880-4748

ANNUAL REPORT2006

TANDEM ACCELERATOR COMPLEX
Research Facility Center for Science and Technology
University of Tsukuba
http://www.tac.tsukuba.ac.jp/

UTTAC-76, 2007

UTTAC
ANNUAL REPORT 2006

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

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

UTTACANNUAL REPORT 2006
April 1, 2006 – March 31, 2007

UTTAC-76 2007

Executive Editors: Yasuo Nagashima
Editors: Tetsuro Komatsubara, Kimikazu Sasa, Yoshihiro Yamato

Cover photo: Autumn at UTTAC.

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 © 2007 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
During the academic year 2006, from April 2006 to March 2007, efforts have been paid to thestable operation both of 12UD Pelletron and 1MV Tandetron as well as to the construction of new beamlines. The new line for a μ-beam PIXE analysis has been thrown into research works as a new service.
Several PIXE measurements such as fluid inclusions in quartz or element analysis in human hairs havebeen commenced.
In the field of element analysis, the 36Cl accelerator mass spectrometry, 36Cl-AMS, has been
intensively used as a tool for studying of the A-bomb peak in the groundwater sampled at the root of Mt.
Fuji. The 36Cl- AMS made a contribution to assess the nuclear waste clearance level. A hydrogen analysis
with p-p elastic-recoil coincidence method has been applied to the geological research. Both the AMS andthe Hydrogen analysis have been applied to the many research fields. A study of nano-particle formationin H2O-N2 mixture gases has been commenced with 20 MeV proton beam. The Eu concentration in
Eu-doped GaN has been estimated by Ruthford backscattering spectroscopy, RBS.
In atomic and condensed matter physics, the evolution of resonant coherent excitation ofhydrogen-like ions has been observed with a 180° electron spectroscopy. Nano-scale and high aspect ratio
patterns were created on the SiO2 and TiO2 substances with accelerated fast heavy ions.
In the field of nuclear physics, a search for the resonant state in p+Si at the (p,n) thresholdenergy was precisely performed. A 118Sn(d,p) reaction was intensively studied to look for deuteron
Coulomb stripping. As a non-accelerator study, a conversion electron Mössbauer study on γ-Fe2O3
epitaxial thin films was pursued.
The agreement for both an academic exchange and an exchange of students has been extended
with the Department of Nuclear Physics, the China Institute of Atomic Energy (CIAE), China. In
accordance with this agreement, the UTTAC accepted a Chinese graduate student until the beginning ofDecember, 2006 and three scientists in October 2006. Five UTTAC persons including an officer and threetechnicians were sent to the CIAE for discussion and information gathering.
The UTTAC organized a symposium entitled “new evolution toward to the interdisciplinary
usage of the heavy ion beams produced by a multi tandem accelerator system”. This symposium wassponsored by the KEK-Tsukuba university co-operative research project.
An undertaking proposal has been granted by the Ministry of Education, Culture and Sport ofJapan as a five year project starting from April 1st, 2007. The total budget of the project is predetermined~300 million Yen and we are expecting this project might enforce the direction for a future of UTTAC.
Finally, Prof. H. Kudo has assumed office as a UTTAC director for the next year. Dr. Y. Aoki
who was an effective user has retired. His contribution to the UTTAC is greatly acknowledged.

Yasuo Nagashima
Director-i-CONTENTS

1. ACCELERATOR AND EXPERIMENTAL FACILITIES
1.1

Accelerator operation 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1

2. NUCLEAR PHYSICS
2.1

CDCC analysis of Oppenheimer-Phillips process . . . . . . . . . . . . . . . . . . . . . .

5

2.2

Resonance search in 28 Si+p system around (p,n) threshold . . . . . . . . . . . . . . . . .

92.3

118 Sn(d,p) reaction in search for Coulomb stripping of deuteron IV

2.4

Measurement of the time response in Hybrid Photo Detector . . . . . . . . . . . . . . . . 14

2.5

Radiation damage study of PHENIX VTX Si sensor . . . . . . . . . . . . . . . . . . . . 16

. . . . . . . . . . . . 12

3. ATOMIC AND SOLID STATE PHYSICS, AND CLUSTER SCIENCE
3.1

Size of track potential in KCl studied with a cluster beam . . . . . . . . . . . . . . . . . . 19

3.2

Nanoparticle formation in H2 O/N2 mixtures under irradiation of 20 MeV protons . . . . . 21

3.3

Vicinage effect on the energy loss of carbon clusters . . . . . . . . . . . . . . . . . . . . 23

3.4

The science of 3d transition-metal oxide system (2006-2007) . . . . . . . . . . . . . . . . 25

3.5

Estimation of Eu concentration in Eu-doped GaN by RBS measurements . . . . . . . . . 27

3.6

Conversion Electron Möesbauer Spectroscopy (CENS) of γ-Fe2 O3 epitaxial thin films . . 28

4. ION BEAM ANALYSIS AND APPLICATION
4.1

Status of Tsukuba AMS system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.2
4.3

129 I AMS by a 97 Mo16 O molecular pilot beam method . . . . . . . . . . . . . . . . . . .
2
36 Cl concentrations in the Dome Fuji ice core, Antarctica . . . . . . . . . . . . . . . . . .

4.4

Chlorine-36 in precipitation in Tsukuba . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4.5

33
35

Estimation of thermal neutron fluences in the concrete of verious accelerator facilities by
35 Cl AMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4.6

Chemical compositions and 36 Cl contents in chondrite meteorites . . . . . . . . . . . . . 39

4.7

Quantitative PIXE analyses of fluid inclusions in quartz by using 1.92 MeV proton beam . 41

4.8First result of target preparation by the HIVIPP method in higher pressure than 1 atm. . . 43

4.9High sensitive biosensors based on perforated waveguide structure . . . . . . . . . . . . . 46

4.10 Detection sensitivity of ERCS hydrogen analysis . . . . . . . . . . . . . . . . . . . . . . 48
5. RELATED TOPICS
5.1

Micro on-chip pH-stat based on an irregular use of a thin-film three-electrode system . . . 51

6. LIST OF PUBLICATIONS
6.1

Journals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

6.2

International conferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

7. THESES

58- iii -

8. SEMINARS

59

9. SYMPOSIA

61

10. LIST OF PERSONEL

63- iv -

1.
ACCELERATOR AND EXPERIMENTAL FACILITIES1.1

Accelerator operation 2006

K. Sasa, S. Ishii, T. Takahashi, Y. Yamato, H. Kimura, H. Oshima, Y. Tajima, T. Komatsubara
and Y. Nagashima.
The 12UD Pelletron tandem accelerator
The total service time for the 12 UD Pelletron tandem accelerator users was 3,060 hours for the fiscal
year 2006. During the service time, the accelerator operating time and the experimental beam time were
1875.1 and 1396.3 hours, respectively. The accelerator operating time was about 80 % relative to that in2005. Fig.1 shows the accelerator operation hours per month. The beam time histogram with respect to theterminal voltage is shown in Fig.2. Fig.3 represents the percentage of the operation hours for the three ion
sources and ion species. Fig.4 shows the percentage of the experimental beam time for the runningresearch fields by the 12UD Pelletron tandem accelerator.
250

Machine Operation Hours

200
150

100

50
0

2006
Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

2007
Jan

Feb

Mar

Fig.1. Accelerator operation hours per month for the fiscal year 2006.

11 MV
10 MV
9 MV
Terminal Voltage

8 MV
7 MV
6 MV
5 MV
4 MV
3 MV
2 MV
1 MV
0

100

200

300

400

500

600

700

800

900

Beam Hours

Fig.2. Beam time histogram as a function of the terminal voltage.

1

1000

127Ｉ
0.8%

129Ｉ
1.0%

AMS
Ion Source

1H
26.9%

36Cl
33.7%

SputterIon Source

2H
15.7%
35Cl
4.7%
1H
8.2%

197Au
3.7%

Polarized
Ion Source

79Br
3.6%

16O
0.4%

12C
1.3%

Fig.3. Percentage of the operation hours for the three ion sources and ion species.

Applied Ion Beam
Science(Heavy-ion
bombardment)
7.3 %Developments(Instruments andDetectors)
1.5%

Education
0.6%

Radiation safety
0.4 % Accelerator science
0.4 %Accelerator Mass
Spectrometry(AMS)
40.2 %

Earth Science(Hydrogen analysis)
8.2%
Atomic and solidstate physics(Droplet formation)
10.5 %

Nuclear Physics(Nuclear reaction)
31.0 %

Fig.4. Percentage of the experimental beam time for the running research fields.
Because asbestos removal from the ion source floor and the SF6 gas handling room was executedfrom February to March in 2007, the accelerator operating period was limited until January 2007. The
scheduled maintenance in the spring 2007 was started on February 7. It was one month early comparedwith the normal schedule, therefore the accelerator operating period became one month shorter for the
fiscal year 2006. The operating time at the terminal voltage of 10 MV accounted for nearly all of the beamtime. The research field of the AMS study was the largest beam time ratio for the fiscal year 2006. Ion
specie of 36Cl for the AMS study was used the most with respect to operating hours.

2In the year of 2006, we had some troubles with the SF6 gas handling system by reason ofdeterioration of the overage facility, especially problems occurred to the gas compressor system. When thetransportation of the SF6 gas, cooling pure water was leaked from the cooling pipe in the gas compressor
and flowed into the accelerator tank and the SF6 gas storage tanks. The SF6 gas handing system is underrepair.
The 1MV Tandetron accelerator
The total service time for the 1 MV Tandetron accelerator users was 1,680 hours for the fiscal year
2006. The accelerator operating time and the experimental beam time were 652.4 and 289.0 hours,
respectively. The accelerator operating time was about 187 % relative to that in 2005. Fig. 5 shows thepercentage of accelerated ions with the 1MV Tandetron accelerator. Fig.6 shows the percentage of theexperimental beam time for the running research fields. The main research fields of the 1MV Tandetron
accelerator were the cluster physics, particle induced X-ray emission (PIXE) and Rutherford
backscattering spectroscopy (RBS). The 1 MV Tandetron accelerator was also used for learning by
experience about the accelerator science mainly for high school students and undergraduates.
H 18.8 %He 1.8 %C 3.2 %

C cluster
76.2 %

Fig.5. Percentage of accelerated ions with the 1MV Tandetron accelerator.
Accelerator
Science
2.0 %Education
2.1 %RBS･ ERDA
4.5 %
PIXE
15.2 %

Clusterphysics
76.2 %

Fig.6. Percentage of the experimental beam time for the running research fields with the 1MV
Tandetron accelerator.

3

4

2.
NUCLEAR PHYSICS

2.1

CDCC analysis of Oppenheimer-Phillips process

Y. Aoki, M.Iijima, T. Ishikawa, D. Inomata and N. Okumura 1
After Lawrence et al.,[1] reported that the energy dependence of low energy deuteron induced reaction
cross section is moderate than predicted by Gamow theory, Oppenheimer and Phillips[2] explained thisenergy dependence is due to Coulomb break up of incident deuteron followed by a liberated neutron
capture.
We expect that the Coulomb break up process should accurately be described by continuum discretizedcoupled channels(CDCC)[3] analysis and neutron absorption cross section can be estimated by the expectation value of the imaginary part of the neutron optical potential. Based on this idea, we evaluated thefollowing quantity for the process, we name OP process hereafter,µ¯¶¯π¯ j J ¯2 2 µR nC
σ (d, p) = −∑ (2J + 1) ∑ ¯χL j L0 ¯ h̄2 W j j .
(2I0 + 1) K03 J L0
R
jLj

(1)

In this expression I0 and K0 are spin and wave number of incident deuterons, χLj jJL0 represent the center ofmass motion of the beak up ‘deuteron’ with the incident and exit channel orbital angular momenta L0 and
L j and W jnj stands for the matrix element of imaginary part of the neutron optical potential sandwichedby the scattering state wave function of p-n system, whose quantum number is collectively labeled “j”.
Because scattering state wave function extends out to infinity, matrix elements W jnj stretches out more than
the imaginary potential itself, i.e., weak energy dependence of neutron capture cross section is expected.
Reid soft core potential[4] was used to generate deuteron bound state and scattering states of 3 S1 3D , 3D , 3P
3
3
1
2
0, 1 and P2 - F2 .

Gaussian potential[3], which reproduce phase shift of 3 D3 state, was also

used. Nucleon optical potential at half the deuteron kinetic energy of CH89[5] was used as the interaction
between target and nucleons in the incident deuteron.
118 Sn(d,p) reaction is taken as a sample reaction. Figure 1 shows the energy dependence of neutron

absorption cross section evaluated by using eq. (1). To study the role of Coulomb break up, off diagonal
Coulomb matrix element is neglected, χLj jJL0 are reevaluated and σ C (d, p) is also evaluated, i.e., purenuclear break up followed by a neutron capture. Importance of Coulomb break up process can clearly beseen in the figure. Differential cross sections of 2s1/2 neutron transfer to form the ground state in 119 Sn
are evaluated by using zero range DWBA program. Angle integrated values are also plotted in the figure
to compare the energy dependence. Absolute values of the zero-range DWBA line is normalized to thatof “no CBU” at Ed = 10 MeV. If we were to fit these energy dependence by exp (−2 π η)/E N , N=10 for“with CBU” and N=6-7 for the rest of the lines.
Binding energy dependence of the “deuteron” should be one of the key parameter of the OP process.
Potential depths of 3 S1 -3 D1 states, i.e., central, spin orbit and tensor potentials of Reid [4] are scaled togenerate wave functions of the bound and scattering states of 3 S1 -3 D1 . Fig. 2 shows this scaling parameter
dependence of the virtual “deuteron”.
Two reactions are studied, (1) binding energy dependence of OP cross sections of 118 Sn(d,p) reaction
at E“d 00 = 5 MeV and (2) incident energy dependence of 40 Ca(00 d 00 ,p) reaction for BE(“d”)=0.1 MeV and1 Nagano National College of Technology

51.0E+04

1.0E+03with CBU118(mb)

1.0E+02

Sn+d

no CBU
1.0E+01

1.0E+00

1.0E-01ZR DWBA
1.0E-02
2

3

4

5

6
Ed (MeV)

7

8

9

10

Fig. 1. Energy dependence of neutron absorption cross sections. Solid line, labeled “with CBU”, corresponds to that with Coulomb break up. Only nuclear break up is taken into account to draw thickdashed line, which is labeled “no CBU”. Thin dashed line is for zero-range DWBA calculation.

E“d 00 =0.5 to 2 MeV. Fig. 3 shows the binding energy dependence of the former case.
Fig. 4 shows the incident energy dependence of virtual “deuteron” induced 40 Ca(“d”,p) reaction. Because binding energy is very low and Coulomb interaction is not very strong as that of the Sn target,
nuclear break up contribution is stronger than that of Coulomb potential. The two contributions interfere
destructively. Two lowest energy points can be fit by using σ (BU) ∝ exp (−2 π η)/E 1.86 . If the corresponding data, evaluated by replacing χLj jJL0 by that of “deuteron” ground state, exponent reduces to 1.14,
i.e., σ (GS) ∝ exp (−2 π η)/E 1.14 . This means that the incident energy of 0.5 to 0.75 MeV is roughly low
enough to use the Gamow approximation. Even in this incident energy, energy dependence of OP process
is not so steep as the Gamow prediction.

References[1] Ernest O. Lawrence, Edwin McMillan and R.L. Thornton, Phys. Rev., 48, 494(1935).
[2] J.R. Oppenheimer and M. Phillips, Phys. Rev., 48, 500(1935).
[3] M. Kamimura, M. Yahiro, Y. Iseri, Y. Sakuragi, H. Kameyama and M. Kawai, Prog. Theo. Phys. Jpn.
89,1(1986).
[4] R.V. Reid, Jr., Ann. Phys. 40, 411(1968).
[5] R.L. Varner, Phys. Rep. 201, 59(1991).

6

9
8

Virtual deut. param.

7
6
PD(%)

5
4

Q (mb)

3
AD/AS (%)

2

BE (MeV)

1
0
0.85

0.9

0.95
Vscale1

1.05

Fig. 2. Scaling factor dependence of the deuteron parameters. Pd (%) for D-state probability in percent,
Q(mb) for electric quadrupole moment in millibarn, AD /As (×100) for asymptotic ratio multipliedby 100 and BE(MeV ) for binding energy in MeV. Electric quadrupole moment increases whenbinding energy is decreased.

1.0E+05
118

Sn + "d"OP Xsec (mb)

1.0E+04

1.0E+03

1.0E+02
0

0.5

1

1.5

2
2.5
BE (MeV)

3

3.5

4

Fig. 3. Binding energy dependence of OP cross sections in 118 Sn(d,p) reaction. OP cross section σ increases exponentially with decreasing binding energy BE[MeV] as σ ∝ exp {−2 × (BE)}.

7

OP Xsec (mb)exp(-2π η)/E**1.86

1.0E+05
40

Ca + "d"BE("d")=100 keV

1.0E+04
0.4

0.6

0.8

1

1.2
1.4
E"d" (MeV)

1.6

1.8

2

Fig. 4. Incident energy dependence of OP cross sections in 40 Ca(“d”,p) reaction. Binding energy of thevirtual “deuteron” is 100 keV. Two lines, “with CBU” and “no CBU” overlap except for E“d 00 = 0.5
MeV, where “with CBU” point is located at about half way for “no CBU” point.

8

2.2

Resonance search in 28 Si+p system around (p,n) threshold

Y. Aoki, M.Iijima, D. Inomata, T. Ishikawa, Y. Tagishi and N. Okumura 1
Proton elastic scattering experiment was performed on nat Si target to study if resonance like behavior
can be seen near the (p,n) threshold. Important experimental trait can be explained as follows, see fig. 1.
We used 100 µm thick target and observed momentum spectrum of elastic protons at backward angles,
typically 135◦ . Due to the energy losses through the thick target, momenta of elastic protons reflect the
proton energy at the elastic scattering really take place. As is shown in the figure, energy of the elasticallyscattered protons which leave the target range from 14.31 to 12.90 MeV. Energy range of 0.56 MeV of theincident energy is expanded by the energy loss after elastic scattering. By measuring relative intensitiesof this elastic protons, we can measure the “excitation curve” of 15.64 ≤ E p ≤ 16.2 MeV by a single
measurement.
14.3105 MeV

12.8989 MeV

energy loss
13.8134 MeV
16.20 MeV
beam

energy loss
=0.5633 MeV

target100µm Si

Fig. 1. Details of proton energy loss during the elastic scattering in the thick target. Protons of E p = 16.2
MeV impinge onto the target and loose energy of 0.56 MeV during the passage through the target.
Some tiny fraction of the protons are elastically scattered by 135◦ , depositing the kinetic energy
and leave the target.

Target thickness was adjusted so that the maximum kinetic energy of inelastically scattered protons isless than the least kinetic energy of the elastic protons. Momentum analysis of ejectile protons are madeby using a magnetic spectrograph, ESP90[1]. Protons are detected by a position sensitive proportionalcounter[2], which are backed by another proportional veto counter. Typical spectrum is shown in fig. 2.
Incident energy was changed from 19 to 14.5 MeV by about 300 keV step to make superposition of
the ejectile spectrum easily. Fig. 3 shows the double differential cross sections thus obtained.
Many structure can be seen in the figure. Presence of threshold anomaly can be suggested by thisfigure. Polarized proton beam from Lamb shift type ion source[3] was used and vector analyzing power
Ay was measured. Quench ratio method was used to measure the beam polarization. Fig. 4 shows the Ayat θlab = 135◦ . A little improved energy resolution is realized. A small peak, which corresponds to the(p,n) threshold can clearly be seen.
1 Nagano National College of Technology

9expjune 28Si(p,p) Elab=16.45MeV
9000
8000
7000

counts/ch

6000
5000
4000
3000
2000
1000
0
0

200

400

600

800

1000

channelFig. 2. Typical momentum spectrum for E p = 16.45 MeV. A broad peak located around 500 to 800 channels correspond to elastic scattering, while the one at 200 to 500 channels for inelastic scattering28
29, 30 Si are very small and canleading to the 2+
1 state in Si. Intensities of elastic protons fromonly be identified by magnifying the figure and are neglected in the following analyses.

In summary, an anomaly can be identified at the (p,n) threshold energy. There are many structure in
the double differential cross section and Ay curve, however. It is difficult to conclude there is a definite
threshold anomaly.

References[1] J.E. Spencer and H.A. Enge, Nucl. Instr. Meth., 49, 181(1967).
[2] H. Iida, Y. Aoki, K. Yagi and M. Matoba, Nucl. Instr. Meth., 224, 432(1984).
[3] Y. Tagishi and J. Sanada, Nucl. Instr. Meth., 164, 411(1979).

10

28Si(p,p) cross section
1000
900

cross section [mb/sr/MeV]

800
700
600
500
400
300
200
100
0
14

15

16
Ecm [MeV]

17

18

Fig. 3. Double differential cross section of elastic scattering of28 Si+p system at θlab = 135◦ . Thresholdenergy of neutron knock on reaction is indicated by a solid line at 15.1 MeV.

28Si(p,p) Ay
0.5
0.4
0.3
0.2

Ay

0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
14

15

16
Ecm [MeV]

17

18

Fig. 4. Energy dependence of vector analyzing power Ay in elastic scattering of 28 Si + p. Solid verticalline indicates the (p,n) threshold energy.

11

2.3

118 Sn(d,p) reaction in search for Coulomb stripping of deuteron. IV

M.Iijima, T.Ishikawa, D.Inomata and Y.Aoki
The idea of Coulomb stripping was proposed by Oppenheimer and Phillips [1] in the 1930s. They
thought that a neutron was absorbed following a Coulomb break-up of a deuteron. Later in the 1990s
Bencze and Chandler [2] showed that the Oppenheimer-Phillips process produces negligible effect on the
cross sections. Aoki [3] recently calculated total reaction cross sections by solving CDCC equation. The
calculations were carried out with and without the Coulomb break-up contributions. It suggested Coulomb
stripping was probable with a target of a large atomic number and the incident energy considerably lower
than the Coulomb barrier.
We thought that reactions of ∆ l = 0 transfer would be preferred at sub-Coulomb energy and chose
118 Sn as a target, whose recoiled nucleus 119 Sn has a ground state ofs1/2 . We measured energy depen-

dence of the sum of the differential cross sections for 118 Sn(d, p) reactions leading to the ground, the first(23.9 keV) and the second (89.5 keV) excited states of 119 Sn, because we could not separate these threelevels.
In the experiment, deuteron beams from 12 UD Pelletron at University of Tsukuba Tandem Accelerator Complex (UTTAC) were used. The deuterons hit 118 Sn target and elastically scattered deuterons and(d,p) protons were momentum analyzed by a spectrograph ESP90. They were then detected by a position
sensitive single wire proportional chamber (SWPC) placed on the focal plane.
We started the experiment at Elab = 6.0 MeV and lowered it to 5, 4, · · · MeV. We prepared selfsupporting enriched 118 Sn targets and a target with Au backings. The self-supporting targets were used todσdetermine dΩfor 118 Sn(d, p0,1,2 ) reactions at Elab = 6.0 MeV. The target with Au backings was used tomeasure relative yields of 118 Sn(d, p0,1,2 ) reactions at Elab = 3.2 ∼ 6.0 MeV. Fig. 1 is a typical spectrumof protons taken with the SWPC at Elab = 3.2 MeV. The yields obtained between Elab = 3.2 ∼ 5.0 MeV
dσ
were normalized to dΩ
at Elab = 6.0 MeV.
dσ
Thus determined dΩ
for the sum of the 118 Sn(d, p0,1,2 ) reactions were plotted in Fig. 2. The curved line

in Fig. 2 is zero-range DWBA calculations performed for the 118 Sn(d, p0 ) reaction. The DWBA values arenormalized to the experiments at Elab = 6.0 MeV. The DWBA calculations show good agreements with experimental values at Elab = 4.0, 5.0MeV, whereas it underestimates cross sections at Elab = 3.2, 3.5MeV.
That might be due to the effect of Coulomb stripping. We are planning to perform CDCC calculations andcomparing them with experiments.

References[1] J. R. Oppenheimer and M. Phillips, Phys. Rev. 48, 500 (1935)[2] Gy. Bencze and Colston Chandler, Phys. Rev. C 53, 880 (1996)[3] Y. Aoki et al., UTTAC Annual Report, 71, 22(2003)

12

Fig. 1. A typical spectrum of protonsdσ
and DWBA calculation
Fig. 2. dΩ

13

2.4

Measurement of the time response in Hybrid Photo Detector

T. Moriguchi, Y. Hashizume, T. Hoya, Y. Yasuda and A. Ozawa
The construction of the Isochronous Storage Ring is projected at RIKEN RI Beam Factory (RIBF) .
The Storage Ring will be able to measure mass of RI to investigate the R-process path. To perform
individual injection [1] , the Kicker magnet of the Ring should be excited by the trigger signal in thedetectors in BigRIPS. Thus, the trigger signal which transit from the trigger detector to the Kicker magnet
must be faster than the arrival of RI at the Kicker magnet. The prediction of the time of flight (TOF) is~880ns for RI beam from the trigger detector to the Kicker magnet. On the other hand, the trigger signal,
is ~850ns, considering the transmission time of the circuit and cable and rise time of the Kicker magnet
except the transit time of the trigger detector. Here, we assumed to use a photo multi tube (PMT) that thetransit time is generally ~30ns. Therefore, it is more desirable for the trigger detector to have the fastertransit time. We also considered using the trigger detector as a TOF detector which needs a good time
resolution.
A Hybrid Photo Detector (HPD) [2] has a fast transit time. Figure 1 shows a schematic view of themultiplication mechanism in HPD. The structure of HPD is that an Avalanche Photo Diode (APD) is
included in the vacuum tube with a photo cathode. Photo-Electrons (PEs) which are emitted from a photo
cathode are accelerated by 8.5kV high voltage. When accelerated PEs strike against APD, the kinetic
energy of PEs is used for creating electron-hole pairs. This mechanism is called the bombarded gain(~103) . Created electrons cause an avalanche effect in APD with 150V bias voltage. This avalanche gain
is about 50. So the total gain of HPD is ~104. Since this multiplication mechanism of HPD is different
from the mechanism due to the multi dynodes like PMT, a transit time of HPD is fast. Figure 2 shows
HPD (HAMAMATSU R7110U-07) that we used in this experiment.

Fig.1. Schematic view of the multiplication
mechanism in HPD.

Fig.2. HPD (HAMAMATSU R7110U-07)
that we used in this experiment.

14

The experiment was performed at 1F course with Q-D-Q magnets in the 12UD tandem accelerator of
UTTAC using 60MeV carbon beam. The beam intensity was 1nA. Figure 3 shows a schematic view of theexperimental setup. HPD was connected to the plastic scintillator (BC408 50x50x0.6) . The another sideof the scintillator was connected to PMT (HAMAMATSU R4998) in order to measure the differences of
the transit time of both detectors. A 2μm Au foil was installed at the entrance of Q-D-Q to decrease thebeam intensity. The intensity was 500cps at the scintillator. A coincidence signal between HPD and PMT
was used as a trigger signal when we took data of the time resolution.
Figure 4 shows typical pulse shapes from two detectors without preamplifiers which was monitored byan oscilloscope. As shown in Fig.4, HPD signal is about 10ns faster than PMT. Since the pulse height of
HPD was 1.5mV, we used preamplifiers (ORTEC AN302/N) and measured the time resolution of HPD.
The typical time resolution of HPD was 664ps (σ) . It is noted that the time resolution of PMT was 137ps(σ) on using 17MeV proton beam [3] .
In summary, the transit time of HPD is faster than PMT and the time resolution of HPD is worse than
PMT. In future, we will investigate to improve the time resolution of HPD.

Fig.3. Schematic view of the experimental set up.

Fig.4. Typical pulse shapes which upper andlower are HPD and PMT, respectively.

References[1] I. Meshkov et al., Nucl. Instrum. Methods A 523 (2004) 262.
[2] M. Suyama et al., IEEE Trans. Nucl. Sci. 44 (1997) 985.
[3] Y. Hashizume et al., UTTAC Annual Report 2005, UTTAC-75 (2006) 20.

15

2.5

Radiation damage study of PHENIX VTX Si sensor

J. Asai1 , R. Ichimiya1 , M. Kawashima,2 T. Komatsubara, K. Kurita2 , K. Sakashita3

1

Introduction

Si vertex detector(VTX)[1] is currently under construction as an upgrade project for the RHIC-PHENIX
experiment. Due to the high luminosity environment expected during the future runs, the radiation damage
effect is of major concern. Among the several radiation damage effects, the amount of leakage current
increase is the biggest problem for us. It is because our DC-coupled preamplifiers will saturate when theleakage current reaches 15nA/channel. Therefore, the main purpose of this experiment was to detemine
the leakage current increase of the actual Si sensor after proton beam irradiation.
Al board

Cu foilCu foil

16 MeV
proton beam
Faradaycup

20 MeV
proton beam

Al spreader
Reference
Stripixel
Junki
chiAsaidiodesensor

1

Fig. 1. Beam test setup with 16 MeV protons.

2

Beam irradiation test setup

In preparation for the tests, we designed a printed circuit board (PCB) for the stripixel sensor. Before
the beam irradiation tests, stripixel sensors were mounted on the PCB and pre-irradiation leakage current
measurements were done.
It is necessary to avoid localization in beam experiments to simulate almost uniform irradiation in theactual PHENIX environment. The setup of the 16 MeV proton irradiation test is shown in Fig. 1. The
original 20 MeV proton beam from the Tandem Van de Graaff accelerator was spread with a 0.5 mm
thick aluminum plate by Coulomb multiple scattering. The standard deviation of the spread was 3.8 cm
at the sensor under test. The energy of the beam after the spreader was also affected and the mean valueenergy of the beam was 16 MeV. An aluminum collimator plate of 5 mm thickness was placed 150 cm
downstream of the spreader. The Al collimator had a square opening of the size 30×30 mm2 which wasaligned to the center of the beam. A Cu foil was mounted in front of the collimator and it had the same
opening so that the beam directly entered the stripixel sensor. The Al collimator size was 200×150 mm2
to cover the PCB. One full stripixel pattern of the sensor was irradiated with 16 MeV proton spread beamthrough the opening of the collimator. A reference diode was placed by the side of the stripixel sensor on
the front Cu foil. A Faraday cup was used for the beam fluence monitor at the end of the beam line. A
magnetic field was applied to the cup to sweep away escaping secondary electrons.
1 RIKEN
2 Rikkyo University
3 Tokyo Institute of Technology

16

3

Fluence determination

The fluence at the stripixel sensor position was estimated from the reference diode, which was irradiatedtogether with the stripixel sensor. The estimation required a geometrical correction due to the Gaussian
shape of the beam profile.
In order to measure the beam profile at the stripixel sensor, a plane Cu foil without a rectangularopening was irradiated at the same location as that of the test stripixel sensor. The proton beam had
the same energy and the same intensity distribution. After the irradiation was over, the activated Cu foil
(63 Zn∗ ) was taken out from the chamber and was laid on an imaging plate (IP) to transfer the intensity map.
The IP is a 2-dimensional radiation recording device, which can be read out by scanning laser stimulated
luminescence. [2] The shape of the distribution was found to be consistent within a few percent with thecalculated Coulomb multiple scattering.
We evaluated the average fluence for the whole stripixel sensor area using the measured distribution.
The average fluence of the stripixel sensor was 93% of that of the beam center, while that of the reference
diode was 73%. The fluence at the stripixel sensor was finally determined to be 2.4×1012 Neq /cm2 bytaking into consideration the ratio of the average fluences measured and the hardness factor 3.0 for 16
MeV protons. This value was equivalent to 10 years of RHIC running. While the relative intensity of theactivation was determined with the IP measurement, the absolute number of protons which irradiated thestripixel sensor was confirmed by the amount of the known γ ray intensities from the activated Cu foil.

4

Result

The increase of leakage current was estimated at 20 ◦ C. The current related damage rate α was determinedfrom the temperature history recorded by a temperature logger, which was installed in the same setup. The
increase of leakage current is defined as difference between the pre-irradiation and post-annealing leakage
current at VFD and T = 20 ◦ C. The annealing was done at 60 ◦ C for 80 minutes. The final measurement
result was (74± 30%) nA/channel and it was found that we need to set the operation temperature of the
Si sensors at least down to 0 ◦ C to reduce the actural leakage current. This information will be fed back to
the design of the mounting sturucture and the cooling system of VTX.

References[1] Z. Li, et al., Nucl. Instr.and Meth. A 518 (2004) 300-304, A 518 (2004) 738-753, A 535 (2004)
404-409, A 541 (2005) 137-143[2] Sonoda M, Takano M, Migahara J, Kato H. Computed radiography utilizing scanning laser stimulated
luminescence. Radiology. 1983;148:833-838.

17

18

3.
ATOMIC AND SOLID STATE PHYSICS,
AND
CLUSTER SCIENCE

3.1

Size of track potential in KCl studied with a cluster beam

H. Arai, S. Tomita, S. Ishii, K. Sasa and H. Kudo
Empirically, the yield of secondary electron by fast ion bomberdment is propotional to the electronic
stopping power for conducting materials. For insulators, however, it is known that there is deviation fromthis relation. This could be due to so-called ”track potential” [1]. When fast ions impinge on insulating
materials, electrons are scattered, and positively charged region is created. The positively charged region
captures a part of the scattered electrons, and results in the reduction of secondary electron yield [2]. But
there is only qualitative discussions on the problem, so far. More experimental observations are required
to characterize the track potential. In present work, we investigated on the size of the track potential byusing fast cluster ions.
When fast cluster ions are incident on insulator, a set of track potential fields is induced by individual
atoms in the cluster. If the radius of track is larger than the distance between the cluster atoms, the potential
fields overlap each other and become higher than for the case of single atom injection which, as a result,effectively reduce amount of secondary electrons. Therefore, by comparing the cluster-induced secondary
electron yields from insulators and conductors, we can obtain infomation about the size of track potential.
Schematic drawing of the experimental setup is shown in Fig 1. Beams of carbon cluster ions wereobtaned from the 1 MV Tandetron accelerator at UTTAC. The cluster ions from accelerator impinged on
the target where a voltage of V = −30 V was applied. About 1 cm upstream from the target, a grounded
plate was placed, so that the emitted electrons in the backward direction were accelerated and detected inan electron spectrometer. The spectrometer is a 45◦ parallel-plate electrostatic spectrometer of the double
deflection type. The electrons were counted by a channeltron detector whose anode potential was set to200 V to increase the detection efficiency of low energy electrons. To monitor the beam intensity, a beam
chopper was placed just after aparture. The secondary electrons from the chopping electrode were detectedwith another channeltron. In the front of the channeltron, a grid electrode held at 100 V was placed so that
only the electrons which have energies higher than 100 eV were detected. No vicinage effect is expected
for such high-energy electron yield, therefore the electron yield is propotional to the beam intensity. Theenergy of the carbon clusters C+
n (n =1 to 4) was 0.5 MeV/atom. The targets used were KCl for insulator
and highly oriented pyrolytic graphite (HOPG) for conductor which could not induce the track potential.
The vacuum pressure was ∼ 3 × 10−6 Pa during the beam irradiation.
The relative electron yield, i.e. the ratio of the yield per cluster to the yield for n=1 are shown in Fig.2
as a function of cluster size n. The result for HOPG reproduces the reduction of the yields from Yn /Y1 = n,as already reported [3]. If the track potentials overlap each other, the potential become higher than thecase of single atom injection, and thereforethe additional reduction have to be observed for KCl. But there
is no discernible difference between KCl and HOPG cases. From the present experiments, we conclude
that the track potentials induced by the clusters do not have effective overlaps. These results indicate thatthe track potential radius is the same order to the interatomic distance (∼ 1.3 Å) in the impinging clusters.

19

Beam Chopper

Target Holder

Beam Current Monitor
KCl

Heater+Faraday Cup

HOPG

C‫ޓ‬
n Cluster Beam
0.5 MeV/atom

pA

-30V
Electron Spectrometer(∆E/E = 3.3 %)Fig. 1. Schematic drawing of the experimental setup.
4
HOPG
KCl

Yn/Y1

3

2

1

0

0

1

2

3

4

5

Cluster size nFig. 2. Relative electron yield as a function of the cluster size n. Dotted line indicates Yn /Y1 = n.

References[1] J. E. Borovsky et al., Phys. Rev. A 43, 1433 (1991).
[2] K. Kimura et al., Nucl. Instrum. Methods Phys. Res. B 193, 661 (2002).
[3] H. Kudo et al., Jpn. J. Appl. Phys. 45, 565 (2006).

20

3.2

Nanoparticle formation in H2O/N2 mixtures under irradiation of 20
MeV protons

S. Kanda, M. Fujieda, M. Imanaka 1 , K. Sasa, S. Tomita and H. Kudo
The strong correlation between the Earth's total low-altitude cloud cover and galactic cosmic ray flux is
first reported in 1997 [1]. However, the mechanism of cloud production by galactic cosmic rays is not
fully understood yet. One possible explanation is that atmospheric ions produced by galactic cosmic raysenhance the nucleation and early growth of ultrafine condensation nuclei from trace precursor vapors andwater in the atmosphere. The ultrafine condensation nuclei eventually grow into the cloud condensation
nuclei with about 100 nm diameter.
To study the ion-induced nucleation mechanism, we measured the size distribution of water droplet
formed from humidified nitrogen by ion-induced nucleation. The ions were introduced either by
irradiation of 20 MeV protons or by corona discharge. The experiments were conducted at the tandem
accelerator, University of Tsukuba (UTTAC). The sizes of the droplets formed inside the humidified
nitrogen were measured by a differential mobility analyzer (DMA).

Current (fA)

150a) Positive particle

150

100

100

50

50

0

0
1

b) Negative particle

1

10
Diameter (nm)10
Diameter (nm)Fig. 1. Spectra of diameter of nanoparticles formed by irradiation of 20
MeV protons. The solid and dotted curves represent the spectra for
humidified and dried nitrogen, respectively.
The size distributions of ion-induced droplets are shown in Fig. 1. Both positively and negatively
charged droplets with diameter of about 10 nm are clearly observed only with humidified nitrogen, which
confirm the production of water nanoparticles by ion nucleation. The yield of positive particle is almost
1

RIKEN, Wako, Saitama, 351-0198, Japan21

the same as that of negative particle.

Current (fA)

100

50

0
1

10
Diameter (nm)Fig. 2. Spectra of diameter of nanoparticle formed by corona discharge.
The solid and dotted curves represent the humidified and dried cases,
respectively. The humidity was 80 %. The discharge voltage was 8.4 kV.

On the other hand, the nanoparticles can not be observed with corona discharge (Fig. 2) except somepeaks due to contamination.
The protons produce both positive and negative ions in a sample gas, while there are only positive ionswhen ionized by corona discharge. This fact implies importance of the presence of both positive andnegative ions, which attract each other by coulomb interactions. As a result, the enhancement of collision
probability allows the formation of 10 nm droplets.

References[1] H. Svensmark and E. Friis-Christensen, J. Atoms. Solar Terr. Phys. 59,1225 (1997)

22

3.3

Vicinage effect on the energy loss of carbon clusters

M. Murakami, S. Tomita, T. Nishimura, S. Ishii, K. Sasa and H. Kudo
When fast molecular ions are incident on a solid, the energy loss per atom is different from that ofsingle atomic ions. This is known as “vicinage effect” and first reported in 1974 for H2+[1]. The energy
loss of H2+ is lower than that of equal-velocity H+ at low injection energy, and becomes larger than H+ athigh energies. In 1992 Baudin et al. [5] performed similar experiments with fast carbon clusters and foundhigher energy loss is for clusters than atomic ions at high energies. The results are quantitatively
understood by considering the interference of electrons scattered by individual atoms[2, 6]. According to
the theoretical calculation, the energy loss of carbon cluster becomes lower at low injection energies likefor the case of hydrogen molecule. But, this is not observed yet. Indeed, the reported data suffered large
experimental errors more than 10%[3, 4]. More precise measurement is required.
The main causes of the large error bar are pulse height defect of solid state detector (SSD) which is
expected to occur for fast Cn+[7] and time fluctuations of electric devices. To improve the experimental
quality, we introduced a new target device and used backscattering technique to measure the energy ofions transmitted through thin carbon foils. Fig.1 shows experimental set up. A thin carbon foil was
mounted on one side of double frame which underwent metronomic motion together with other empty
frame. The projectiles transmitted either through the foil or the empty frame hit thin Au target placed atjust downstream of the device. The energy of the scattered carbon atoms by the target was measured with
SSD at a backward angle, so that only carbon atom was detected. In this way, we avoid pulse height defectof SSD. The target device allowed almost simultaneous measurement with and without target, whichcanceled the fluctuations of electric devices.
In Fig.2, the results are shown together with theoretical predictions. There can be seen a slight but
perceptible difference from atomic ion. The energy loss for cluster ions is lower than that of atomic ion at
0.5 MeV/atom, and agrees with theoretical values. The experimental error of the present data is estimatedto be about ±1% which is much better than that of former experiments. The improved experimental
methods enable us to perform more detailed comparison with theoretical calculations.

23

SSD
Pipe

100°
Pendulum

Ion beam
φ1.5

ApertureAu(~0.3nm) on HOPG Faraday cup~6×10-6Pa

Fig. 1. Schematic view of the experimental setup in the scattering chamber.

39
1.00
0.98
0.96

37

0.94
36

⊿E (C+n)/n⊿E (C1+)⊿E / n

(keV)

38

0.92
35
1

2

3

4

0.90

Cluster size nFig. 2. Energy loss per atom of 0.5MeV/atom Cn+ (circles) plotted together
with theoretical prediction from Ref.[6] for ring (triangles) and linear
structures (squares).
References[1] W. Brandt, A. Ratkowski, and R.H. Ritchie, Phys. Rev. Lett. 33, 1325 (1974)[2] N.R. Arista, Phys. Rev. B, 18, 1 (1978)[3] K. Narumi et al, Nucl. Instrum. Methods Phys. Res. B. 135, 77 (1998)[4] C. Tomaschko et al, Nucl. Instrum. Methods Phys. Res. B. 103, 407 (1995)[5] K. Baudin et al, Nucl. Instrum. Methods Phys. Res. B. 94, 341 (1994)[6] T. Kaneko, Phys. Rev. A. 66, 052901 (2002)[7] M. Seidl, et al, Nucl. Instrum. Methods Phys. Res. B. 183, 502 (2001)

24

3.4

The science of 3d transition-metal oxide system (2006–2007)

M. Onoda, T. Ikeda, K. Takao, Y. Kikuchi, A. Sasaki, W. Onoda, T. Maekoya, Y. Mizuguchi, I. Gotoh
and S. Tsunegi
The structural and electronic properties of 3d transition-metal oxides and bronzes have been exploredby means of x-ray four-circle diffraction and through measurements of magnetic resonance (NMR and
ESR), magnetization, and electronic transport, in order to extract characteristic properties in the quantum spin-fluctuation system, correlated electron system, electron-phonon-coupling system, and novel
materials such as a new type of superconductors, composite crystals, thermoelectric devices and secondary ion batteries [1, 2]. At the Tandem Accelerator Center, Varian continuous-wave and Bruker
pulse NMR spectrometers have been used. This report describes briefly recent progress for the correlated
electron system [1].
The structural and electronic properties of the triangular lattice system Nax CoO2 with nominal compositions of 0.7 ≤ x ≤ 1 annealed at temperatures from 923 to 1123 K have been investigated. According
to the annealing temperature, these properties for the single-phase specimens vary significantly, since thechemical composition as well as the local structure is modified. The overall temperature dependencesof thermoelectric power are approximately explained with the two conduction path model and those ofmagnetic susceptibility at high temperatures are fitted with the Curie−Weiss law. The specimens annealed
below Tac that ranges from 973 to 1023 K have the enhanced gap for the poor metallic carriers and they areless magnetic having the Curie constant almost consistent with the localized electron model. On the other
hand, above Tac , the apparent gap of poor metallic carriers is reduced significantly and the Curie−Weissparameters are enhanced, and the antiferromagnetic or spin density wave-like transition takes place. At
this transition temperature, the resistivity becomes smaller than the value extrapolated from the high temperature side and the thermoelectric power exhibits a hump. This suggests that spin fluctuations are mainly
responsible for the transport mechanism. Alternatively, the Nax CoO2 is considered to be located near theboundary between the antiferromagnetic metal and the correlated metal as in the case of the perovskite
system La1−x Srx TiO3 with x ≈ 0.05. It should be noted that many of the investigations performed todate are for the specimens annealed above Tac . In order to clarify the properties of the present systemcompletely, it is very necessary to know the absolute chemical composition of Nax−δ Co1−δ 0 O2 .
The first-order phase transitions of the electrical resistivities are observed irrespective of the coolingcondition, which may be due to the ordering of Na ions. Since the susceptibility data do not exhibit any
transition at the corresponding temperature, the resistivity anomaly is purely related to the charge dynamics. In addition, the irreversible transitions in the heated process are detected with the fast cooling (FC)down to a certain temperature. Our recent study for the single-crystal specimens with 0.48 ≤ x ≤ 0.65,
outside of the composition for the present specimens, does not exhibit these transitions at temperatures
below room temperature [2]. The difference for the resistivity anomalies may be due to the metastability
in the local structure of the polycrystalline specimens rather than the difference of the composition, whichshould be revealed from a microscopic point of view.
As shown in Fig. 1, the NMR spectrum of 23 Na nuclei in Na0.8 CoO2 consists of two kinds of peaks,
expected from a presence of two independent Na sites in the crystal structure. The hyperfine field trans-

25

!

"
"
#
ν $%% !&% '()∆ν νFig. 1. The NMR spectra of 23 Na nuclei in Na0.8 CoO2 at room temperature.

ferred from Co ions for the Na1 site is considered to be larger than that for the Na2 site. Thus, the spectrumwith a large shift may come from the Na1 site. After FC, the signal changes clearly as compared withthat for the as-grown specimens. This suggests the rearrangement of Na1 ions, which is likely related tothe irreversible transition of the resistivity described above. In addition, the Q-factor of NMR coil after
FC increases as compared with that for the as-grown specimen, suggesting that the FC process leads toan increase of the resistivity. It is quite likely that the irreversible transition of resistivity comes from themetastability in the local structure of polycrystalline sample, since it is known that a fast cooling induces
a metal−semimetal transition in the organic superconductor.
The 59 Co-NMR study in the triangular lattice superconductor Na0.3 CoO2 · 1.3H2 O is also being performed, which will be reported in future.
The NMR measurements described here have been done in collaboration with Y. Uchida, National
Institute for Materials Science.

References[1] T. Ikeda and M. Onoda: J. Phys.: Condens. Matter 18 (2006) 8673–8682.
[2] M. Onoda and T. Ikeda: J. Phys.: Condens. Matter 19 (2007) 186213 (14pp).

26

3.5

Estimation of Eu concentration in Eu-doped GaN by RBS
measurements

J. Sawahata, J.W. Seo, S.Nemoto and K. Akimoto
Rare earth (RE) doped GaN thin films have attracted great interests due to their unique opticalproperties, that is, luminescence due to an intra 4f transition of RE ion depends very little on the hostmaterial and the temperature. Among the several RE dopants, it is well known that europium (Eu) shows astrong red emission around 622 nm. The Eu concentration in the films is a one of important parameters on
the optical properties of Eu-doped GaN. Therefore, we performed Rutherford back scattering (RBS)
measurements to estimate Eu concentration in Eu-doped GaN.
The Eu-doped GaN thin films were grown on GaN/Al2O3 substrates by molecular beam epitaxy
methods [1]. The RBS measurements were carried out using 1.5 MeV accelerated 4He ions with a tandem
accelerator placed at UTTAC. The geometry of incident angle, exit angle and scattering angle were 30, 0
and 150 degrees, respectively. A detector was placed at 70 mm from the sample surface.
Fig. 1 shows a RBS spectrum of Eu-doped GaN as an example. The spectrum heights of the edges
corresponding to scattering from the surface atoms were used for calculation of Eu concentration. In Fig.1,
the Eu concentration was estimated at 3 at.%. The red emission intensity of Eu-doped GaN increased up toan Eu concentration of 3 at.%, and then it decreased for Eu concentration of more than 3 at.%. Therefore,
wefound that an optimum Eu concentration on the optical properties of Eu-doped GaN is estimatedaround 3 at.% by RBS measurements.

1400

GaN:Eu/GaN/Al2O3

1200Counts

1000
800
600
400
200
0

0

200

400

600

800

1000

ChunnelFig. 1 RBS spectrum of Eu-doped GaN
References[1] H. Bang, S. Morishima, J. Sawahata, J. Seo, M. Takiguchi, M. Tsunemi, K. Akimoto, Appl. Phys. Lett.
85, 227 (2004)

27

3.6

Conversion Electron Möessbauer Spectroscopy (CEMS) of γ-Fe2 O3
epitaxial thin films

M. Minagawa, Y. Toyoda, M. Hasegawa, H.Yanagihara and Eiji Kita
Recently, growth techniques for γ-Fe2 O3 epitaxial films have been developed by several groups[1, 2].
An detailed x-ray diffraction analysis revealed that the unit cell of the grown film is three times larger thanthat of Fe3 O4 [2] and that the B-site vacancies are fully ordered along c-axis parallel to the film growth
direction. The thickness of the film was around 10 nm and its CEMS was examined last year.[3] Fromthe preliminary experiment, it is found that physical properties were getting similar to those of Fe3 O4
when the film thickness was increased more than 20nm. This fact implies that the electronic structure andvacancies on spinel B sites are dependent on the film thickness.
Use of 57 Fe enriched materials has been a powerful tool for the Mössbauer spectroscopy because natural abundance of Mössbauer active 57 Fe atoms is only 3 % and rest of Fe atoms, 56 Fe, are not Mössbauer
nuclei. Especially for thin film researches, the enrichment with 57 Fe is has been used to pronounce magnetic properties at the limited area such as surface and interface regions.
In this report, dependence of the structure on the thickness of γ-Fe2 O3 epitaxial films grown on
MgO(001) was examined by inserting 57 Fe oxide layers during the deposition. The film growth method
was the same as the way reported in the last annual report. We performed conversion electron Mössbauer
spectroscopy (CEMS) at room temperature.
Single crystal thin films were prepared with a reactive vacuum deposition technique on MgO(001) single crystal substrates.[2] Ozone of 10−6 Torr was used as a reactive gas during deposition. The samples tosurvey the thickness variation of the structure was made by placing 5nm of 57 Fe oxide layers always 5 nmapart from the top of the film surface. The outermost 5 nm was made of natural Fe(not enriched) to avoid
the influence from the surface. 4 samples with different total thickness were prepared and schematicallyillustrated in Fig. 1. It is noted that the thickness used here is a nominal thickness of metallic iron thenactual thickness of the oxide will be about 1.3 times thicker.
CEMS spectra with different locations of the 57 Fe enriched layer are shown in Fig. 2. The spectrum
for the 10 nm sample mainly consists of a subspectrum originated from Fe3+ ion. Small amount of asubspectrum with smaller hyperfine field was observed in the 20 nm sample. This subspectrum became
clear when the total thickness increased. For the sample(d), the area ratio of the subspectra to the Fe3+
subspectrum was roughly estimated to be 0.5 and its hyperfine parameters were agreed with those of Fe2.5+

MgO substrate(a) 10 nm(b) 20 nm(c) 30 nm(d) 40 nm

Fig. 1. Samples for the thickness dependent Conversion Electron Mössbauer Spectrum(CEMS) of γFe2 O3 films. The hatched area depicts the location of 5 nm 57 Fe layers for each sample.

28

(b) 20 nm
Intensity (arb.units)

Intensity (arb.units)(a) 10 nm

Fe3+

Fe3+

Fe2.5+

Fe2.5+

Intensity (arb.units)(d) 40 nm

Intensity (arb.units)(c) 30 nm

-15

-10

-5

Fe3+

Fe3+

Fe2.5+

Fe2.5+

0

5

10

15

Velocity (mm/s)

-15

-10

-5

0

5

10

15

Velocity (mm/s)

Fig. 2. Conversion Electron Mössbauer Spectra(CEMS) of γ-Fe2 O3 films with the different location of
57 Fe layers, which is schematically described in Fig. 1.

ions observed in Fe3 O4 . The Fe2.5+ subspectrum observed in stoichiometric Fe3 O4 has an area ratio of
2 against the Fe3+ subspectrum. Therefore, the Fe oxide thin film prepared with the present technique iscomposed of γ-Fe2 O3 when the thickness is less than 20 nm and tends to be a intermediate phase between
γ-Fe2 O3 and Fe3 O4 . It is supported by the increase of Fe2.5+ subspectrum area in the CEMS spectra.
RHEED observation revealed that the crystal structure dose not change during deposition. This fact
implies that the basic crystal structure keeps spinal-type when the thickness increases. To keep γ-Fe2 O3phase stable in more thicker films, it might be necessary to precisely control a condition of Ozone gas
sources. Signal to noise ratios were remarkably dropped compared with the γ-Fe2 O3 thin film with 7 nm
in thickness(5 nm in nominal Fe thickness). Improvement of the S/N ratio in the CEMS study will lead toclear conclusion in this study.

References[1] F. C. Voogt, T. Fujii, P. J. M. Smulders, L. Niesen, M. A. James and T. Hibma, Phys. Rev. B 60 (1999)
11193.
[2] H. Yanagihara, M. Hasegawa, E. Kita, Y. Wakabayashi, H. Sawa, and K. Siratori, J. Phys. Soc. Jpn.
75 (2006) 054708.
[3] M. Hasegawa, K. Shibata, H. Yanagihara, E. Kita, UTTAC Annual report 2005 (University of Tsukuba,2006) p.29, M. Hasegawa, H. Yanagihara, Yuta Toyoda, Eiji Kita, L. Ranno, J. Magn. Magn. Mater.
310 (2007) 2283.

29

30

4.
ION BEAM ANALYSIS AND APPLICATION

4.1

Status of Tsukuba AMS system

Y.Nagashima, K.Sasa, T.Takahashi, Y.Tosaki, M.Tamari, B.Zhou, K.Sueki, K.Bessho, H.Matsumura,
T.Miura and K.Masumoto
In parallel with the AMS measurements, the improvements of both an AMS ion source systemand terminal stabilization system have been done. First, the improvements done this year, and second, theexperimental results are reported briefly.
The beam optics for the ion source has been improved and consequently the 35Cl- ion current
increased from ∼10μA to ∼40μA. The strong 35Cl- current helps very much to realize the measurement of
the samples with very small 36Cl to 35Cl ratio. The best configuration of the ion source we got is shown in
Fig. 1. According to the result of the electric field calculation, the target voltage and the ionizer voltage areadjusted to -18kV and -16.5kV, respectively. Therefore, the sputtering energy of the Cs+ beam is decreased
from 2.5keV to 1.5keV. This low energy of the Cs+ beam helps very much to measure the very small
amount of sample such as less than 1mg of sample because of very small sample consumption. We
understand that the shape of both an ionizer and an extraction electrode are not ideal. Therefore, they were
replaced with newly designed one. The Cs+ beam with about 2mm in diameter hits on the sample with
0.5mm radius and consequently the 35Cl- beam with about 2mm in diameter can be produced.
The stable operation of a terminal high voltage is essentially requested for the stable AMS
measurement. A terminal voltage stabilizer uses the beam currents sensed by an image slit and keeps theterminal voltage stably. The accuracy of the terminal voltage, however, was insufficient for the accurate
AMS measurements because of lack of the current sensitivity of the image slit. Therefore, in order toensure the stable and accurate AMS measurements, an operation mode of the image slit has been changed
from a continuous (DC) mode to a pulse operation mode. The pulse operation mode tremendously
improves the sensitivity of the image slit and a fluctuation of the beam energy becomes smaller. As aresult of this modification, the reproducibility of the 36Cl to 35Cl ratio of the standard sample by the AMS
measurement has been improved from 10% to 2%.
The dating of ice core sampled at the Fuji dome in the Antarctica Continent as a big national
project is in progress. The depth of the ice bed at the Fuji dome is about 3,000m and the core samples
are collected from the surface to the 3,000m depth. It is estimated that the age of the core sample at the
3,000m depth is ∼100 million years old. Therefore, it is expected that the core sample memorizes therecord of not only an environmental change of the earth but also a change of a solar activities for the 100
million years. To investigate and to understand the change, our efforts have been bended on themeasurements of 36Cl element in the ice core by mean of 36Cl-AMS.
A calculated fall out of the 36Cl on the ice bed is ∼60 atoms/m2/s and the number of the 36Cl in
the ice core is ∼6×103 atoms/g. The 36Cl/Cl ratio is estimated to be the range from 10-14 to 10-15. To
accommodate lowering the 36Cl/Cl ratio, several improvements have been performed both on the AMS ion
source.
The distance between 127I- ion trajectory and 129I- one is only ~3mm at an image point of the 120

31degree magnet. The ~3mm separation is insufficient to measure both 127I- and 129I- correctly because theboth particles are overlapped and a part of 129I- particles are intersected by a Faraday cup with which the127

I- current is measured. This missing of 129I measurement caused a lowering of efficiency and accuracyof the 129I AMS measurement. Therefore, in order to improve the accuracy of 129I to 127I ratio measurement,a new 127I beam deflector is installed in a 120 degree scattering chamber. The distance between 127I- ion
trajectory and 129I- one is expanded from ~3mm to ~9mm. The ~9mm distance is sufficient to be able tomeasure 127I- without any disturbance on the 129I- particle.

Fig. 1 Calculation of Cs+ beam trajectories and 36Cl- beam envelope at the ion source andan einzel lens. The diameter of the Cs+ beam spot on the sample is about 2.0mm.

32

4.2

129

I AMS by a 97Mo16O2 molecular pilot beam method

B.Zhou, Y.Nagashima, K.Sasa, T.Takahashi, Y.Tosaki, M.Tamari, K.Sueki, K.Bessho, H.Matsumura, andT.MiuraA Tsukuba AMS system is now used for the steady measurements of 26Al and 36Cl in the various
research fields such as the environmental sciences. Adding to these elements, 129I high sensitive
measurement by the mean of the AMS is strongly requested because the 129I measurement with a thermal
neutron activation method shows the limits. The sensitivity of the method is limited to about 10-8 order ofthe ratio of 129I to 127I. The 130I-decay γ measurement are strongly disturbed by the 130Xe-decay γ because
both γ lays have almost the same energies, E=536KeV. And consequently, the sensitivity of 129I
measurement by the neutron activation method is limited to 10-8. On the other hand, the 129I-AMS has no
isobaric disturbance and enables us to measure 129I with very high sensitivity such as 10-13 ratio.
Fig. 1 shows the outline of the Tsukuba 129I-AMS system. As we have already reported insomewhere [5-7], in stead of a generating voltage feedback method, a molecular pilot beam feedback
method is introduced. An acceleration voltage of the tandem accelerator can be kept within 0.1% accuracy
with the pilot beam method. Maximum voltage of the tandem is up to 12MV and this high voltage makes
us easier to identify 26Al or 36Cl elements from isobaric elements such as 26Mg or 36S. Two thin, 10μg/cm2,
stripper foils are used. One is set in the terminal section as a charge exchange foil and second one isprepared in the AMS beam line in order to sweep out the pilot beam by following an energy and a
momentum selector.
An electric beam deflector has been installed in a vacuum chamber located at an 120 degree
dipole magnetic in the ion source section. Fig.2 shows the beam deflector. The purpose of this installation
is to expand the separation between a 129I- ion trajectory and a 127I- ion one. We are expecting the 127Icurrent can be measured more precisely by using this deflector and consequently more accurate
measurement might be realized.
In order to know the background level of the 129I measurement, two kinds of samples aremeasured. These are a sample of only 97MoO2 molecular element, and a mixture of AgI reagent and97

MoO2. Fig. 3 shows the results of these measurements. The separation of 97Mo and 129I is perfect and97

Mo causes no influence on the 129I counting. In case of 97MoO2 solo sample, there is no observation in

the region of 129I collection. On the other hand, in the AgI reagent measurement, seven (7) 129I counts aredetected. These elements apparently came from AgI reagent itself, not from the system, because of no 129I
detection in the measurement of 97MoO2 sample. If we consider one event in the seven is originated fromthe system background, the one count corresponds to 1x10-13 ratio of 129I to 127I. Though we are confident
that the system background is lower than 1x10-13, at this moment, we say that 1x10-13 is the maximum
sensitivity.
Three samples are prepared by diluting the NIST high level 129I standard, SRM-3231. The ratiosof 129I to 127I of these standards are carefully estimated to be 7.0×10-10, 6.9×10-11, and 7.0×10-12. In order toget suitable 97Mo9+ current that is used to control the acceleration voltage of the tandem, the mixture ratio33

of the AgI sample to 97Mo16O2 element is controlled to be 10. The energy spectra of these samples areshown in the Fig. 4. Similar to the background measurements, the 129I yields are clearly identified from theyield of 97Mo. Therefore, instead of the TOF detector, a SSD detector is used for the measurements
because of no appearance of disturbance by the background. Linearity and re-productivity of themeasurements are checked with three samples. The ratios of 129I to 127I of the samples are reasonably large
and spread from 10-11 to 10-9. Though the numbers of measurements are only three, we can probably saythat the accuracy of our 129I-AMS measurement is within 3% in the range of 10-9 to 10-11 ratio of 129I to 127I.
A flat top characteristic at the terminal stripper foil was measured and it was ∼3 gauss. The 3 gauss flat top
corresponds to 0.1 % stability. This 3 gauss is enough to keep the stable transmission of the 129I particles
because the stabilities of all of the electric equipment used in the tandem are better than 0.01%.

Fig.1 Outline of the Tsukuba 129I AMS system
1000

97

Mo

Fig. 2
10000

97

MoO2
AgI Reagent

1

CountsCounts

129

I

0

100

200

300

400

500

I

97

Mo

100
10
1

600

0

100

EnergyFig. 3129−

10 12 std.
−
10 11 std.
−
10 10 std.

1000

100

10

An electrostatic deflector for 127I

200

300

400

EnergyBackground measurements

Fig. 434

Standard samples

500

600

4.3

36

Cl concentrations in the Dome Fuji ice core, Antarctica.

K. Sasa, Y. Matsushi, Y. Tosaki, M. Tamari, Y. Nagashima, T. Takahashi, K. Sueki, K. Bessho 1 , H.
Matsumura1, Y. Shibata2, H. Motoyama3 and K. Horiuchi4
The concentration of cosmogenic radioisotopes in the ice core provide useful information about thehistory of the cosmic ray flux in the atmosphere, the past solar activity and the past earth environment
such as changes in the geomagnetic field. We have been taking part in the joint research project toinvestigate the variation of the cosmogenic radioisotopes 10Be (T1/2 = 1.51 × 106 years), 26Al (7.16 × 105
years) and 36Cl (3.01 × 105 years) in the ice core retrieved from the Dome Fuji station in collaboration with
National Institute of Polar Research, National Institute for Environmental Studies, Hirosaki University andthe University of Tokyo. We present here the first results of the cosmogenic radioisotope 36Cl
measurements in the deep ice core samples at the Dome Fuji station (DF02). 36Cl−AMS was performed
with the energy of 100 MeV by using a multi-nuclide AMS system at the University of Tsukuba (Tsukuba
AMS system) [1]. In this study, we used the 1.5 m long cut sample of the DF02 core in the range from 2400
to 3028 m. The typical weight of the 1.5 m long cut sample was approximately 140 g. We merged 5 to 8
samples together for 36Cl-AMS measurements. After adding 0.75 mg of stable chlorine as carrier to theintegrated sample, 36Cl and the carrier were extracted together by means of anion exchange resin. The
sample was prepared as AgCl, and a saturated benzene solution of fullerene (C60) was added to it for theC3− pilot beam method [1].

12

In the year of 2006, we measured 13 samples in the DF02 core to estimate the ice core age by the 36Cl
radioactive decay. The measured 36Cl/Cl ratios were in the range of 5.4 – 29.1 × 10−14. The 36Cl
concentrations in the DF02 core correspond to 0.14 – 0.60 × 104 atoms g−1. There are some relationships
comparison between the 36Cl concentrations and the paleoclimatic parameter δ18O. The 36Cl fluxes range
with 0.42 – 2.18 × 104 atoms cm−2 yr−1, which are calculated by the accumulation rate [2] estimated from
δ18O data. The 36Cl fluxes in the deep ice core are decreasing with the depth. This result agrees with theradioactive decay of 36Cl. Once locked in the ice, only the radioactive decay is responsible for a reductionof the cosmogenic radioisotope with age. This suggests that the 36Cl analysis will be able to provide age
constraints for the deep ice core.
Acknowledgements
This work is supported in part by the Grants-in-Aid for Scientific Research Program of the Ministry of
Education, Culture, Sports, Science and Technology, Japan.
References[1] K. Sasa et al., Nuclear Instruments and Methods in Physics Research B 259 (2007) 41–46.
[2] K. Satow et al., Polar Meteorol. Glaciol., 13 (1999) 43-52.
1

Radiation Science Center, High Energy Accelerator Research Organization
National Institute for Environmental Studies
3
National Institute of Polar Research
4
Hirosaki University
2

35

4.4

Chlorine-36 in precipitation in Tsukuba

Y. Tosaki, N. Tase, K. Sasa, T. Takahashi, Y. Matsushi 1 , M. Tamari, Y. Nagashima, K. Sueki, K. Bessho 2
and H. Matsumura2
The meteoric 36Cl is mainly produced through the spallation reaction, 40Ar(p,α)36Cl, in the stratosphere.
After about two years [1], stratospheric 36Cl enters the troposphere and is washed out by precipitation
within a mean residence time of one week [2]. This meteoric input of 36Cl to groundwater, along withmarine-derived stable chlorine, is reflected as the background 36Cl/Cl ratio of groundwater. Knowledge ofthis ratio is important in order to apply cosmogenic or bomb-produced 36Cl as tracers in groundwaterhydrology.
For the purpose of determining the recent background 36Cl/Cl ratio in Tsukuba, bulk precipitation
samples were collected from April 2004 at the roof of the Natural Sciences building, University ofTsukuba. The precipitation sampler used in this study consists of a PE funnel (diameter 15 or 21 cm), a
HDPE bottle (3 or 5 L) and a specially developed

200

glassware with a ping-pong ball, which prevents

employing anion-exchange column method [4] and the36

Cl/Cl ratios were measured by the Tsukuba AMS

Cl/Cl (10-15)

through a 0.45 μm filter, samples were processed by

150

100

36

evaporative loss of the sample [3]. After being passed(a) 36Cl/Cl ratio

50

system.
The results of 36Cl measurement for monthly

0
2.5

precipitation samples (from April 2004 to May 2006,

2

locations [5,6] and for other cosmogenic radionuclides

mid-latitudes (especially about 30–40°N). As thetropopause rises, stratospherically produced 36Cl istransported into the troposphere and washed out fromthe atmosphere after about one week. This mechanism
would explain our observation.
1
2

36

tropopause begins to rise rapidly in April or May at

Cl flux (atoms m-2 s-1)

(e.g. Be [7]). As pointed out in these studies, theof tropopause height [8]. According to ref. [8], the

0.5
0
100

7

seasonal pattern may be attributed to annual variation

1(c) 36Cl flux
80
60
40
20
0

Jan-06
Feb-06Mar-06
Apr-06
May-06

Similar spring maximum was reported in other

1.5

Apr-04
May-04
Jun-04
Jul-04Aug-04
Sep-04
Oct-04
Nov-04
Dec-04Jan-05
Feb-05Mar-05
Apr-05
May-05
Jun-05Jul-05Aug-05
Sep-05
Oct-05
Nov-05May) was observed in 36Cl concentration and flux.

Cl (106 atoms/l)seasonal variation with peaks in the spring (April or

36

except for December 2005) are given in Fig. 1. A clear(b) 36Cl concentration

Fig. 1. 36Cl in bulk precipitation samples.

Present address: Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo
Radiation Science Center, High Energy Accelerator Research Organization (KEK)36

The measured 36Cl/Cl ratios range from (1.4 ± 0.3) × 10−14 to (1.15 ± 0.08) × 10−13. The average
36

Cl/Cl ratio for the entire sampling period is (3.9 ± 0.2) × 10−14. This ratio would be interpreted as therecent background level in Tsukuba, whereas it disagrees with the 36Cl/Cl ratio of a shallow groundwater
sample, (1.19 ± 0.48) × 10−13, obtained from an observation well (depth of about 2 m from the surface) at
Terrestrial Environment Research Center, University of Tsukuba in 2003. This may suggest another sourceof 36Cl after the deposition of meteoric 36Cl. However, the contribution of epigene 36Cl (36Cl produced insurface rocks or soils) to groundwater is generally small compared to meteoric input [9].
Further investigation is needed to explain this disagreement. We are planning to measure some water
samples with minimum anthropogenic effects such as springs or stream waters around Mt. Tsukuba.
Acknowledgements
We thank Dr. Shiho Yabusaki (Department of Environment Systems, Faculty of Geo-Environmental
Science, Rissho University) for her advice on precipitation sampling.
References[1] H.-A. Synal, J. Beer, G. Bonani, M. Suter, W. Wölfli, Nucl. Instr. and Meth. B 52 (1990) 483.
[2] H.W. Bentley, F.M. Phillips, S.N. Davis, in: P. Fritz, J.-Ch. Fontes (Eds.), Handbook of Environmental
Isotope Geochemistry, Vol. 2, Elsevier, Amsterdam, 1986, p. 427.
[3] J. Shimada, J. Matsutani, S. Dapaah-Siakwan, M. Yoshihara, K. Miyaoka, A. Higuchi, Ann. Rep. Inst.
Geosci. Univ. Tsukuba 20 (1994) 11.
[4] Y. Tosaki, R. Seki, UTTAC Annual Report 2005 (2006) 40.
[5] D.L. Knies, D. Elmore, P. Sharma, S. Vogt, R. Li, M.E. Lipschutz, G. Petty, J. Farrell, M.C. Monaghan,
S. Fritz, E. Agee, Nucl. Instr. and Meth. B 92 (1994) 340.
[6] L.J. Hainsworth, A.C. Mignerey, G.R. Helz, P. Sharma, P.W. Kubik, Nucl. Instr. and Meth. B 92 (1994)
345.
[7] J.E. Dibb, J. Geophys. Res. 94 (1989) 2261.
[8] D.O. Staley, J Atmos. Sci. 19 (1962) 450.
[9] F.M. Phillips, in: P.G. Cook, A.L. Herczeg (Eds.), Environmental Tracers in Subsurface Hydrology,
Kluwer, Boston, 2000, p. 299.

37

4.5

Estimation of thermal neutron fluences in the concrete of various
accelerator facilities by 36Cl AMS

K. Bessho 1 , H. Matsumura1, T. Miura1, K. Masumoto1, T. Suzuki1, H. Hagura1, Y. Nagashima, K. Sasa,
T. Takahashi, R. Seki, K. Sueki, Y. Tosaki, Y. Matsushi, M. Tamari
At accelerator facilities, concrete components around beam lines are exposed to secondary particles
during machine operation, and various radionuclides are accumulated in the concrete. Thermal neutron
fluence generated during machine operation is useful information to estimate the radioactivities of theinduced nuclides because most of the radionuclides are mainly produced by thermal neutron-capture
reactions. Our group has studied the behavior of neutrons inside concrete walls and floors at various
accelerator facilities by 36Cl-AMS, and the thermal neutron fluence inside the concrete had been discussed
based on energies of secondary neutrons.[1,2]In FY 2006, the concrete samples obtained at the Neutrino Beam Line (KEK) were measured. In orderto clarify the origin of the thermal neutrons inside the concrete, distributions and energies of neutrons were
calculated by the MARS code simulation. These results show that thermal neutrons observed at deeper
positions were mainly generated by thermalization of fast-neutrons. Direct penetration of thermal neutrons
from the concrete surfaces was found to be small contributions to thermal neutrons occurred inside theconcrete. The analysis of concrete-cores sampled at different positions in the Neutrino Beam Line will be
continued in FY 2007.
The concrete samples obtained at the buildings of UTTAC Pelletron 12UD were also analyzed in thisyear. Concrete was sampled just under the analyzing magnet, the surface of the floor, and the 36Cl/35Cl
ratio in the concrete was analyzed by 36Cl-AMS. The 36Cl/35Cl ratio at the floor surface was determined tobe (2.66±0.12) x 10-12, and the thermal neutron fluence was estimated to be (6.09±0.27) x 1010 n/cm2. Thisvalue is two to four orders smaller than other accelerators, such as SF-cyclotrons, 1.3GeV electron
synchrotron, and 300MeV electron LINAC.[3] It demonstrated that 36Cl-AMS is highly sensitive anduseful for estimating thermal neutron fluences inside concrete samples, because the gamma-emitting
nuclides, such as 60Co and 152Eu, could not be detected by gamma-ray spectrometry for the same concrete
sample.
References[1] K. Bessho et al., Radiochim. Acta, 94, 801 (2006)[2] K. Bessho et al., Nucl. Instr. Meth. B in press[3] K. Bessho et al., UTTAC Ann. Rep. 2006, 42

1High Energy Accelerator Research Organization

38

4.6

Chemical compositions and 36Cl contents in chondritic meteorites

Y. Oura 1 , S. Yamazaki1, M. Ebihara1,Y. Tosaki, K. Sasa, Y. Nagashima, T. Takahashi, Y. Tosaki,
Y. Matsushi, M. Tamari, K. Sueki, H. Matsumura 2 , K. Bessho2, T. Miura2
Meteorites contain stable and radioactive cosmogenic nuclides, which are produced by nuclear reactions
with high energy cosmic rays during their flights in the space. Cosmogenic nuclides in meteorites provide
important cosmochemical information of the meteorites, e.g. some kinds of age, a size before falling on
the earth, and so on.

36

Cl is a one of the cosmogenic nuclides and produced by several nuclear reactions

such as proton and neutron induced spallation reactions (main target elements: K, Ca, Ti, Cr, Mn, Fe, andNi) and neutron capture reaction (target nuclide: 35Cl). 36Cl in the metal phase mostly consisting of Fe-Ni
alloy in Antarctic meteorites was used to determine their terrestrial age [1, 2] .
easy to use

On the contrary, it is not

36

Cl in silicate phase to get meaningful cosmochemical information because production

36sources of Cl are complicated. However, since 36Cl production excitation functions for proton induced
spallation reaction are varied for different target elements, if production rates of 36Cl for individual target
elements are obtained,

detailed irradiation condition must be estimated. In this study, as the first step for

estimating the irradiation condition of chondrites using 36Cl, we

determined 36Cl contents and chemicalcompositions for several phases separated from chondrites.
Two chondrites, Barwell and Allegan, were used in this sturdy. From powdered whole-rock samples, 6phases with different elemental compositions were separated by both physical and chemical treatments.
Chemical compositions of mainly target elements for bulk and 6 separated phases samples for eachchondrite were determined nondestructively by neutron induced prompt gamma-ray activation analysis
and instrumental neutron activation analysis. For AMS, AgCl precipitates were prepared for each powder
samples. 36Cl/Cl ratios were determined by AMS at the Tandem Accelerator Complex, University ofTsukuba.
In Table 1, chemical compositions and 36Cl concentrations in the bulk and 6 phases for the Barwellmeteorite are listed. The metal phase has the highest 36Cl concentration (22.4 dpm/kg) and silicate phases
contain similar 36Cl contents (6.83 – 8.67 dpm/kg). A similar feature appears in the Allegan meteorites(24.7 dpm/kg for metal and 7.7 – 8.3 dpm/kg for silicatges). Calculation of 36Cl production rate for eachtarget element using simultaneous equations with chemical compositions and 36Cl concentrations failed toyield reasonable values. Then, production rates for 2 elemental pairs, (K + Ca) and (Fe + Ni), whichlargely contribute to 36Cl production, were calculated. Based on values in Table 1, chemical concentrations
were recalculated assuming that a meteorite consists of 9 target elements only. 36Cl concentrations areplotted against (K + Ca) or (Fe + Ni) concentrations, as shown in Fig.1. 36Cl concentration is found toincrease almost linearly with increasing of (K + Ca) concentration and to decrease with decreasing of (Fe+ Ni) concentration.

From the intercept with x = 100,

values of 247 and 25 dpm/kg were obtained as

approximate production rates for (K + Ca) and (Fe + Ni), respectively. Interestingly, similar values, 234
1
2

Graduate School of Science and Engineering, Tokyo Metropolitan University
Radiation Science Center, High Energy Accelerator Research Organization

39

and 24 dpm/kg, were obtained for the Allegan meteorite. Determination of Cl concentrations byradiochemical photon activation analysis is now in progress to estimate the contribution of 35Cl (n, γ)
reaction.

Table 1. Chemical composition and 36Cl concentration in the Barwel meteorites.
bulk

metal

silicate-1

silicate-2

silicate-3

silicate-4

silicate-5

0.09440.192

0.005170.120

0.00257

K [%]0.0839Ca [%]

1.33

0.0140

1.54

2.11

0.342

1.90

Ti [%]

0.06930.003200.06180.149

0.04550.103

Cr [%]

0.317

0.0138

0.362

0.661

0.01080.562

Mn [%]

0.277

0.00585

0.280

0.243

0.165

0.211

Fe [%]

23.7

82.4

18.7

7.82

30.5

6.75

Ni [%]

1.73

5.63

0.26

V [ppm]

67.8

1.2

4.6

132

2.6

114

Co [ppm]

526

6690

110

4.99

1070

5.62

234

Cl [dpm/kg] 8.10

22.4

7.56

8.10

8.67

6.83

8.60

36

2.12

70

Cl-36 [dpm/kg]

60

K + CaFe + Ni

40

30

20
0

Fig.1.

20

36

Cl

40
60
Elemental concentration [%]concentration

vs.

80

target100

elemental

concentration for the Barwell meteorite.
Reerences[1] K. Nishiizumi, D. Elmore, P. W. Kubik, Earth Planet. Sci. Lett. 93 (1989) 299.
[2] K.C. Welten, K. Nishiizumi, M. W. Caffee, Lunar Planet. Sci. 31 (2000) #2077.

40

28.9
0.42

80

50

0.0178

4.7

Quantitative PIXE analyses of fluid inclusions in quartz by using 1.92
MeV proton beam

M. Kurosawa, S. Ishii and K. Sasa
Fluid inclusions are important as the most convincing information of fluid activities andvein-type ore formation in the Earth. In particular, elemental compositions of fluid inclusions provide a
direct evidence for chemistry of fluids and elemental transportation related to magmatic process. Thus,
considerable efforts have been invested in the development of techniques for the precise quantitative
elemental analyses using PIXE [1-4], SR-XRF [5,6], and LA-ICP-MS [7,8]. In this report, we describe
micro-PIXE analyses of single fluid inclusions in quartz by using 1.92 MeV proton beam.
Samples used were fluid inclusions in a quartz crystal of hydrothermal vein from a Miocene
Kofu biotite-granite, Yamanashi Prefecture, Japan. The quartz was cut and double-polished, and a
halite-bearing polyphase inclusion (~30 wt.% NaCl eq.) in the quartz were measured. The fluid inclusion
is an ellipsoidal shape, 58 x 58 x 96 μm in size, and the inclusion depth is 10 μm. The PIXE analyses were
performed at the 1MV Tandetron. A 1.0 to 5.0 nA beam of 1.92-MeV proton was focused to a 96 x 108 μm
spot on the sample using slits and magnetic lenses. The beam incidence was normal to the sample surface,
and the X-ray measurement take-off angle was 45˚[9]. The characteristic X-rays excited by the incident
beam were collected by the Si(Li) X-ray-energy detector (Gresham Co.) with a nominal resolution of 152
eV at 5.9 keV, and the spectra were recorded by a multi-channel analyzer. A 55-μm-thick Mylar film wasused to attenuate the intense X-rays from the predominant light elements and to prevent the entry into thedetector of protons scattered from samples. The total charge was determined by integrating the target
currents, and all samples were analyzed to the integrated charges of 0.5 to 5.0 μC. Analytical points werechosen based on optical viewing using a CCD camera mounted on the microscope [9].
Quantification was performed based on the model of Kurosawa et al. [4]. Intensities of X-rays
generated from fluid inclusions are decreased by the attenuation of energy of the incident protons and theabsorption of the X-rays by a quartz matrix and the fluid

Proton beam

X-ray
45

(Fig. 1). In this model, the decrease of total X-ray
intensities from a whole fluid-inclusion are calculated byconsidering sizes and depth of fluid inclusion, the major
element composition, the densities of the matrix and theinclusion depth

matrix

fluid,(x,y,z)

w

o

l

X

t

Y
Z

Fluid
inclusion

Fig.1. Schematic geometry for PIXE analysis
of fluid inclusion

theirproton-stopping

powers,

the

X-ray

production cross sections, and the X-ray absorption
coefficients.

Finally,element

concentrationsarecalculated based on X-ray intensities corrected for thedecrease and the detector sensitivity determined for eachelement. A shape of the fluid inclusion is assumed as anellipsoidal equal to the size of the measured fluidinclusion. The inclusion sizes and depths (Fig. 1) were41

determined with an optical microscope. The inclusion depths are also exactly determined by measuring an
intensity ratio of Cl Kα and Cl Kβ. The fluid was approximated as 30wt.% NaCl solution. The detector
sensitivity for each element was determined by measurements of thin-film multielement reference samples
and a multi-element reference glass material NIST SRM 1412. The thin-film sample was prepared bydropping several standard solutions for ICP analysis onto a Mylar film and drying the film in a desiccator.
In the calculations, contributions of X-rays from impurities in the matrix and bubbles in the fluid inclusion
were corrected based on the method of Ryan et al. [1]. By using the calculation model, almost traceelements in fluid inclusions at levels of a few to several thousands ppm can be determined with the total
analytical error of ±40 %[4]. Small halite, less than 20 μm in size, in fluid inclusions has no largely effectfor the total analytical error.
Observed spectrum of the fluid
104

Cl

K

Ca

PIXE (1.92 MeV )Fe

inclusion consisted mainly of the K-X ray
peaks from Si, Cl, K, Ca, Mn, Fe, Cu, Zn, Br,

Mn

Rb, Sr, and the L-X ray peaks from Pb (Fig. 2).
The concentrations determined are as follows:

Intensity (cts)Zn

103 SiCu

182000 wt. ppm for Cl, 20600 ppm for K,
14600 ppm for Ca and Fe, 3300 ppm for Mn,

Pb
Ni

102

1200 ppm for Zn, about 500 ppm for Cu and Br,

Br
Rb

Sr

101

and 120-180 ppm for Pb, Rb, and Sr. The
values of almost transition metal elements were
2-3 times higher than those of two-phase fluidinclusions (~10 wt.% NaCl eq.) from miaroritic

5

10
X-ray energy (keV)

15

cavity in the granite. Thus, the enrichment
could relate to a formation of hyper saline
water and a metal separation by boiling of

Fig.2. PIXE spectrum of halite-bearing fluid inclusion
in hydrothermal quartz vein from the Kofu granite
bodyoriginal low-saline fluids (~10 wt.% NaCl eq.)
during adiabatic ascending from a deep part
along the cooling joints of the granite body.

References[1] C. G. Ryan et al., Nucl. Instr. and Meth. B77 (1993), 463.
[2] C. G. Ryan et al., Nucl. Instr. and Meth. B181 (2001), 570.
[3] V. S. Kamenetsky et al., Geology, 30 (2002), 459.
[4] M. Kurosawa et al., Geochim. Cosmochim. Acta, 67 (2003), 4337.
[5] P. Philippot et al. Chem. Geol., 144 (1998), 121.
[6] H. Nagaseki et al., Eur. J. Mineral., 18 (2006), 309.
[7] D. Günther et al., J. Anal. Atom. Spectrom., 13 (1998) 263.
[8] A. Audéat et al., Science, 279 (1998) 2091.
[9] M. Kurosawa et al., Nucl. Instr. and Meth. B142 (1998), 599.

42

4.8

First result of target preparation by the HIVIPP method in higher
pressure than 1 atm.

I.Sugai 1 , Y. Takeda1, M. Oyaizu1, H. Kawakami1, K. Sasa, S.Ishii and K. Shima.
We recently developed a new deposition method of HIVIPP (HIgh energy VIbrational Powder Plating),
which is based on the high energy vibrational motion of powder in the high electric field between parallel
electrodes.
This method is very simple and does not require any complicated mechanisms. We have also found to bevery useful as a target preparation technique in backed condition. The deposition process has beenoriginally performed at room temperature and in vacuum. The deposition process could be further
simplified if it could be carried out at higher than one atmospheric pressure with reactive gases or inert
gases, without a vacuum pumping system. With this motivation, we have tried the target deposition of
non-metallic silicon powders at high pressure of nitrogen, oxygen gases and air than one atm.. The first
result is reported in this paper.
Fig. 1 shows a schematic view of the HIVIPP chamber for high pressure operation. The deposition
container is identical with that mentioned in the previously papers [1−4], except for the high pressure
container and the vacuum system. The deposition container is set in a high pressure container as shown in
Fig. 1, which is composed of Acrylic tube pipe of 290 mm in diameter, 340 mm in high and 20 mm in thepipe thick.
We have investigated non-metallic Si powder for the first test deposition samples. As is well known, theelement of Si have relatively high melting points of 1683 K. Both copper plates of 0.2 mm thick were used
as a backing plate. The experimental apparatus is very simple, composed of two parallel metallic disks of
35 mm in diameter and 0.5 mm thick. These disks serve as the electrodes and hold the backing foil against
the glass tube ring. We have also investigated the relationship between the deposition rates (μg/cm2)
versus high pressure. The deposition rate was tried at one atm. through 9 atm.. We used dried air as
high-pressure gas. The powder to deposit was metallic Cr of nominal 60 μm in particle size and thedeposition time was taken every 1 h. The thicknesses of the deposited targets were measured using anelectronic ultra-microbalance. We used the copper foil of 0.2 mm thick as backing plate and measured thedeposition rate in every one atm. from one atm. to 9 atm..
Fig. 2 shows the result obtained. Error bars represent the root mean square and the numbers attached tothe points are the number of measured sample. From the picture, we can see the maximum deposition rate
showed at the approximately 1.7 atm. of considerably low pressure and the rate was about 90 μg/cm2/h on
average. We can see also that after the 3 atm., the deposition rate was gradually decreased with the highpressure till 9 atm.. The deposition rate from 4 atm. to 9 atm. showed about 50 μg/cm2/h on average. Thisrate is corresponding to nearly 1/2 of that 90 μg/cm2 deposited at 1.7 atm.. The result shown in Fig. 2 gave
us a vital role, because the HIVIPP method at only 2 atm. could be got the maximum deposition rate and
1High Energy Accelerator Research Organization,Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan43

this means that the handling for target deposition is very easy without any so danger due to low pressure.
In addition to these, the high voltage to the electrodes could be applied 26 kV in maximum without thedischarge. The voltage is very important parameter as mentioned in Ref.[1-3]. The deposition rate depends
strongly on the voltage between the electrodes.
Next, in order to gain deeper insight into the observed color change of the Si deposited in the nitrogen,oxygen and air, we investigated the elemental Si deposited on copper backings of 0.2 mm thick. The lightelements of C, N and O and other heavy elements of Si and Cu were detected by taking the PIXE using
Si(Li) X-ray detector with a 1.92 MeV proton beams from the TANDETRON accelerator of University ofTsukuba.
The Si powder was obtained by agate mortal from Si wafer of high purity of 99.999 %. The target
preparation of the Si was performed for 5 h at around 2 atm. Figure 3 shows the obtained spectrum. Fromthe spectrum, we can see clear Si peaks. In the figure we can not see any clear nitrogen peaks in thenitrogen and air medium gases. On the other hand, we can see clear the oxygen peaks with rather strong
from especially in the target prepared in only oxygen medium and also see oxygen peaks from othertargets prepared in the air and nitrogen medium gases. The target prepared in vacuum of 5 × 10−4 Pa
showed a small oxygen peak. Through these first detections, we have found that the nitrogen medium gas
in filled HIVIPP chamber did not react with a high energy non-metallic Si powders and thus the color
changed Si maybe be oxidized with the filled oxygen in the HIVIPP chamber.
As summary and conclusion, we have tried target depositions from the non-metallic Si powder bymeans of the HIVIPP method using high pressure medium gases over one atmosphere without vacuum
pumping system.
The result showed the deposition rate did not depend strongly on the air pressure and the maximum
deposition rate of 90 μg/cm2/h on average around 1.7 atm..
We found that it did not detect any clear nitrogen peak in the deposited target in the nitrogen and air
medium gases. On the other hand, the oxygen element in the Si targets by the both oxygen and the air
medium gases were observed clear the strong oxygen peaks in the both targets. Further experiments areneeded to confirm whether the nitrogen element in targets made in N2 and air gases or not.
Reference[1] I. Sugai, Nucl. Instr. and Meth. A397(1997) 81.
[2] I.Sugai, Nucl. Instr. and Meth.A438(1999)58.
[3] I.Sugai, Y.Takeda, H.Makii, K.Sano, Y.Nagai, Nucl. Instr.and Meth.A521(2004).
[4] I.Sugai, Y.Takeda, H.Kawakami, Nucl.Instr. and Meth.A561(2006)38.

44

Acrylic Disc

300

+

HV

Acrylic
CylindricalChamber-Pressure gauge(Bourdon)

Deposition
Container

340

SamplePowderLaser Inspection
SupportingStage(SUS-304)

Inlet

Supporting
Doughnut(SUS-304)

OutletGas
200

Fig.1 The HIVIPP chamber cross-sectional

Fig.2 Deposition rate (μg/cm2/h) as a function ofview for high pressure operation.

applied high pressure of air (atm.).

Yield [counts]

Yield [counts]

Si (2.55 mg/cm2, Vac.)

Si (0.82 mg/cm2, O2)

Si

Si

O

O

Cu-L

C

C

Si (122 μg/cm2, N2)

Si (0.94 mg/cm2, Air)

Cu-L

Si

Si

O

O

C

C

Channel number

Cu-L

Channel number

Fig.3 Elemental analysis of natural Si targets on copper backings made by the HIVIPP method in vacuumand 2.5 atm. pressure of air, nitrogen and oxygen. The spectra were obtained by the PIXE with a 1.92
MeV proton ion beams from the TANDETRON accelerator of University of Tsukuba.

45

4.9

High sensitive biosensors based on perforated waveguide structure

K. Awazu1, M. Fujimaki1, T. Komatsubara and Y. Ohki2
1. Introduction
We will report here on a strategy to perforate dielectric waveguides to enhance significantly thesensitivity of the sensor as firstly, the perturbation of the modes by adsorbed molecules is enlarged andsecondly, their adhesion surface is increased. The holes in the insulator are created in the following way:
the passage of an atomic particle through an insulator results in the creation of a cylindrical, latent nuclear
track that extends along a straight line corresponding to the path of the atomic particle. The presence of
tracks is revealed after etching in a suitable solution. However, the shape of the etched hole is often not
cylindrical, but conical, with the largest diameter being near the surface. This is a consequence of theetching rate in the latent track being comparable to the general etching rate in the unirradiated region.
Musket et al. have used vapor etching of ion tracks to create high aspect ratio, isolated cylindrical holes
through ~600 nm-thick films of thermally grown silica on silicon [1]. In the present study, we haveadopted the vapor etching technique to create cylindrical holes through silica waveguides.
2. Experimental
As glass substrate we used S-LAH66 glass (Ohara Co., Ltd.) with a high refractive index of 1.769. A
500nm thick-waveguide layer of a-SiO2 film was deposited on an Au film on S-LAH substrate. Ion
bombardment to perforate the waveguide was performed at room temperature at a residual pressure below
1 x 10–4 Pa. The 12 UD Pelletron tandem accelerator at University of Tsukuba was employed with 150
MeV Au14+ ions. To avoid overlap of the individual cylindrical holes, very low ion fluency was required.
This was achieved by diffusing the ion beam through an aluminum foil in forward scattering geometry.
150 MeV Au14+ was reduced to 137 MeV Au30+ by passage through the Al foil. We performed vapor
etching experiments with 20% hydrofluoric acid (HF). Influence of various liquid TL and sample TS
temperatures was examined and TL = 19 ˚C and TS = 30 ˚C were obtained as a best condition. Changing
the temperature allowed for control over the hole sizes.
The substrate glass was mounted on a prism to form an optically contiguous medium. A He-Ne laser
operating at 632.8 nm was used in subsequent measurements and a polarizer selected for either TE- or
TM-polarization. To observe the optical waveguide modes, reflectivity was measured against incident
angle.
3. Results and discussion
SEM images of the fabricated samples provided sufficient evidence that cylindrical holes were etched
into the 500nm-thick silica films. These through holes with a diameter of ~ 50 nm were resulted fromvapor etching. Both, waveguide modes as well as the surface plasmon mode can be excited in the silica
waveguide. The waveguide mode spectrum shifts when the silica waveguide film is exposed to a solution
containing biotin of 500 μM. Reflectivity against incident angle in the vicinity of the TE0 mode wasobtained on the as-prepared silica film before and after

immersion in biotin solution. The central line

shift in the as-prepared sample case was less than 0.01˚ and merely noticeable. The angular resolution in46

this experiment was 0.01˚. Reflectivity against angle was measured around the same mode obtained on
porous silica film with a number of 1 x 1010 cm-2 holes, 500nm deep and 50 nm in diameter. The central
line shift was dramatically increased up to 0.14˚. It was found that the remaining dip intensity wasincreased by the creation of holes and the line width was likewise increased slightly. Both observations areeasily attributed to an increase of the guiding losses of the modes due to additional light scattering at theetched holes.
Angular dependent reflectivity for a TE0 mode before and after capturing streptavidin of 500 nM wasalso examined. For the silica waveguide before creation of pores, dip shift was estimated to be 0.06 ˚.
When a number of 7 x 109 cm–2 holes were created in the silica waveguide, central position of the dip
shifted dramatically by 0.53 ˚. Additional waveguides with increased hole densities were fabricated andthe TE0 spectra were measured. The relationship between dip shift due to capturing of streptavidin andhole density was examined. Change in reflectivity at a constant angle (ΔR/R) could be estimated from theTE0 spectra. For example, reflectivity at 53.56˚ was estimated to be 0.51 before and 0.78 after capturingof streptavidin. Based on those values, we evaluated the relative change in reflectivity (ΔR/R) with respect
to the unexposed sample. ΔR/R values are plotted against hole-density. It was found that the dip shift
increases with number of holes.

The ΔR/R value reached a maximum above 3 x 109 cm–2. Saturation isobserved, as the line width of the unexposed compared to the exposed spectra are no more overlapping.
Such a shift is hardly to achieve with conventional plasmon based sensors. We expect the sensor chips tobe able to detect impurities of ppb order.
4. Summary
Detection of low levels of bio-molecules with guided modes in perforated dielectric waveguides was
explored. It was found that a concentration of 500 μM of biotin, which cannot be detected employing thebulk silica waveguide, could be detected with the perforated silica waveguide. Also by capturing
streptavidin of 500nM, the angular position of the waveguide modes for the TE0 was shifted up to 0.53.
The shifts exceed significantly the line width of the resonance itself, hence allowing for unprecedentedchange in the reflectivity for such low concentration of molecules to be detected. The high sensitivity ofthe present sensor derives from a maximization of the overlap of modal volume and the molecules to be
detected via the nanometer sized holes that were created in the waveguides. The present approach willcontribute significantly towards the development of ultra-high sensitive sensors in various fields.
Reference[1] R.G.Musket, J.M.Yoshiyama, R.J.Contolini, J.D.Porter, J.Appl.Phys., 91, 5760-5764(2002).

1

Center for Applied Near-field Optics Institute, AIST, 1-1-1 Higashi Tsukuba 305-8562, Japan2

Department of Electrical Engineering and Bioscience,Waseda University, Shinjuku, Tokyo 169-8555,

Japan

47

4.10

Detection sensitivity of ERCS hydrogen analysis

T. Komatsubara, K. Sasa, S. Ishii, Y. Yamato, K. Ebisu, T. Kawamata and M. Kurosawa
In order to improve systematic error in Elastic Recoil Coincidence Spectrometry (ERCS) hydrogen
analysis a new method of modification for measured sum spectrum has been developed. Stopping power
for the moving proton in SiO2 or volcanic rock can be approximated as

S ( E ) = aE −b
as a function of the proton energy E, where a and b are fitting parameters. This approximation is rather
better than the inversed linear function which was introduced in reference [1]. By using this approximation
thickness from the entrance surface x can be calculated as

x=

b +1
E sum
− E0b+1 + a (b + 1)2 b +1.5 T

a(b + 1)(2 b +1.5 − 1)

where Esum and E0 are sum energy and incident energy, respectively. Total thickness of the target is denotedby T in a unit of mg/cm2. In this formula, the total thickness T and the incident energy E0 appear explicitly.
However these parameters can change only position of thespectrum, they can be replaced by an adjusting constant asfollows.

x=

b +1
Esum

a(b + 1)(2b+1.5 − 1)

+ constant

By using this formula abscissa of the sum energy spectrum
Esum [MeV] can be converted to depth [mg/cm2].
As an example of the calculation measured spectra and themodified spectra are shown in Fig. 1. The irradiated sample isa melt inclusion trapped by quartz gathered at Zaoh volcano. In
the top spectrum, since the irradiation position is quartz part,two peaks corresponding to holding Mylar films are observed.
The next spectrum is the sum energy spectrum for the melt
inclusion which is large enough to penetrate host quartz. The
third spectrum is a result of correction for only secondary

Fig. 1 Measured spectra and modified

scattering with exponential decrease, where a little incline canspectra.

be observed. The last spectrum is the result of full correctionhydrogen depth distribution.

of the spectrum analysis. The flat distribution is corresponding
to uniformity of hydrogen concentration.
For the evaluation of the measured sensitivity of ERCS
hydrogen analysis, several standard materials were irradiated.

48

The

last

spectrumisMeasured results of the hydrogen concentrations are shownin Fig. 2 compared with reference values. In this analysis
hydrogen concentration of Mylar film is chosen as areference. For the well calibrated materials of Kapton,
Polyethylene, and Ti(H) the measured results by ERCS
analysis agree with the calibrated values within 5% relative
deviation.
The ERCS result for the lowest hydrogen density material
ED-H is shown in Fig. 3 which is a glass plate sample. The
measured hydrogen concentration is rather deviated fromreferenced value reported by FTIR measurement. Lowest
limit of the ERCS hydrogen evaluation can be estimated as 1
ppm weight ration of H.
In the Fig. 3, surface contamination is clearly observed forboth side of the E-DH glass. According to the hydrogen

Fig. 2 Measured results of ERCS
hydrogen analysis comparing to thereference values.

calibration, the peak intensity can be evaluated to be about
20ng/cm2. High sensitivity of the ERCS hydrogen analysis
has been appeared.

References[1] T. Komatsubara et al. Nucl. Instr. and Meth. B251
(2006) 237

Fig. 3 Hydrogen depth distribution for
the EDH sample.

49

50

5.
RELATED TOPICS

5.1

Micro on-chip pH-stat based on an irregular use of a thin-film
three-electrode system

Katsuya Morimoto, Junji Fukuda, and Hiroaki Suzuki
1 INTRODUCTION
For the determination of analytes using biosensors, the detection of a pH change caused by an
enzymatic reaction has been one of the very popular methods. Numerous biosensors based on thedetection principle have been developed including the use of a pH-ISFET. However, a problem with thismode of operation is in that the response is affected by the buffering capacity of the analyte solution to bemeasured [1]. An alternative to alleviate this problem is the use of a pH-stat. A pH-stat is a device which
has a function to maintain the pH of a solution in a chamber and has been used widely for acid-basetitration and the determination of the activities of enzymes that accompany the hydrolysis of an analyte.
However, miniaturization of the currently-used pH-stat was very difficult, because it requires an injection
mechanism to enable timely injection of an accurate amount of titrant. In this study, the pH-stat was
realized based on an irregular use of a thin-film three-electrode system. The mode of operation caused anegative feedback and the pH of the solution to be analyzed could be maintained at a fixed value. Bymeasuring the electric charge generated during the feedback process, titration of an acid or a base wasconducted. We also conducted the on-chip determination of urea using the pH-stat.
2 EXPERIMENTAL
Fabrication of the device
Fig. 1 shows the structure of the on-chip pH-stat. The device consisted of a polydimethylsiloxane(PDMS) compartment and a thin-film three-electrode system on a glass substrate. A pH-sensitive electrodewas used for the reference electrode and was made in direct contact with an analyte solution. A Ag/AgClelectrode was used for the working electrode. The reference and auxiliary electrodes were placed in acompartment and the working electrode was placed in another compartment connected with a liquidjunction. A 0.1 M KCl solution impregnated in a gel was used as an internal electrolyte for the Ag/AgCl

Reservoirs for Ag/AgCl electrodes

Gel containing 0.1 M KCl
Working
electrode(Ag/AgCl)

Reaction chamber

PDMS
10 mm
ReferenceGlasselectrodefor pH-sensing

pH-statpH-sensitive referenceelectrode (Iridium oxide)

Fig. 1 Structure of the micro pH-stat.

51

1 mm

Auxiliaryelectrode(Iridium)electrodes.
Principle of operation
First, a solution of a predetermined pH is filled in the reaction chamber. The value of the resting
potential of the working electrode measured with respect to the reference electrode is applied to theworking electrode by using a potentiostat. When the solution pH in the reaction chamber changes, theoverpotential is applied to the working electrode following the potential change of the pH-sensitivereference electrode. However, even with a very small potential shift, a large current is generated because
the Ag/AgCl electrode is non-polarlizable. Accompanying this change, the electrolysis of water proceedson the auxiliary electrode that surrounds the pH electrode. As a result, the solution pH recovers to theinitial value resulting in a decrease in the overpotential. The amount of protons produced and consumed
accompanying the change is related to the measured electric charge.
3 RESULTS
Fig. 2 shows a typical response curve for the

2.5

Acetic acid added2

Charge (μC)

pH-stat and the dependence of the generated
charge on the concentration of acetic acid orammonia. Linear relationships were observed
betweenthegeneratedchargeandtheconcentration of acetic acid or ammonia. While

25 mV

E vs. Ag/AgCl

pH electrode (reference electrode) in the on-chip

1 min
pH-stat OFF
pH-stat ON

1.5
Time

1

0.5

the pH-stat was operating, the potential of the0

pH electrode recovered to the initial value

0

immediately after a spike of pH change caused

20

40

60

80

100

Concentration (μM)

by adding an aliquot of an acetic acid solution.
When the solution was added under the OFF

Fig. 2 Dependence of the generated charge on thestate, no substantial change was observed in theconcentration of acetic acid (○) and ammonia (□).

potential of the pH electrode.

Added sample volume was 0.1 μl. 10 μl of a 0.1 M

In order to demonstrate the applicability tosodium sulfate solution (pH 6.9, 25˚C) was used as

bio-sensing, the pH-stat was used for thea supporting electrolyte in the reaction chamber.

determination of urea. Urea is hydrolyzed by

The inset shows time courses of the potential of theurease and the solution pH increases as ammonia

pH electrode.

is produced. Therefore, by measuring the pHchange caused by the enzymatic reaction, the concentration of urea can be determined. A linear
relationship was observed between the generated charge and the concentration of urea. Also, thedependence of the buffering capacity on the output was very small.
References[1] K. Morimoto, H. Suzuki, “Micro analysis system for pH and protease activities with an integrated
sample injection mechanism”, Biosensors and Bioelectronics, vol. 22, p. 86-93, 2006.

52

6. LIST OF PUBLICATIONS
The publications listed here are those released in the fiscal year 2006 by all the workers listed on§10.

6.1 Journals
ACCELERATOR AND EXPERIMENTAL FACILITIESNUCLEAR PHYSICS
1. M. Yamaguchi, Y. Tagishi, Y. Aoki, T. Iizuka, T. Nagatomo, T. Shinba, N. Yoshimaru, Y.
Yamato, T. Katabuchi, and M. Tanifuji, Analyzing powers of polarized deuterons in low-energy
6 Li(d,α)4 He and 6 Li(d,p )7 Li reactions in a resonance region PRC 74(2006) 064606. Published
0

12 December 2006 (11 pages)
2. F.Schümann, S.Typel, F.Hammache, K.Sümmerer, F.Uhlig, I.Böttcher, D.Cortina,
A.Förster, M.Gai, H.Geissel, U.Greife, E.Gross, N.Iwasa, P.Koczon, B.Kohlmeyer, R.Kulessa,
H.Kumagai, N.Kurz, M.Menzel, T.Motobayashi, H.Oeshler, A.Ozawa,
M.Ploskon, W.Prokopowicz, E.Schwab, P.Senger, F.Strieder, C.Sturm, Zhi-Yu Sun, G.Surowka,
A.Wagner, and W.Walus, Low-energy cross section of the 7 Be(p, γ)8 B solar fusion reaction
from the Coulomb dissociation of 8 B, Physical Review C, 73, 015806 (2006).
3. A.Ozawa, Y.Z.Cai, Z.Q.Chen, M.Chiba, D.Q.Fang, Z.G.Guo, T.Izumikawa, J.X.Li, R.S.Mao,
T.Ohnishi, W.Q.Shen, T.Suda, Z.Y.Sun, T.Suzuki, I.Tanihata, W.D.Tian, J.S.Wang, M.Wang,
Y.B.Wei, G.Q.Xiao, Z.G.Xiao, T.Yamaguchi, Y.Yamaguchi, A.Yoshida, W.L.Zhan, H.Y.Zhang,
T.Zheng, C.Zhong, Measurements of the interaction cross-sections for 14 Be and 14,15 B as projectiles with a new scheme at RIBLL, Nuclear Instruments and Methods in Physics Research B
247, 155-160 (2006).
4. A.Ozawa, K.Matsuta, T.Nagatomo, M.Mihara, K.Yamada, T.Yamaguchi, T.Ohtsubo, S.Momota,
T.Izumikawa, T.Sumikama, Y.Nakashima, H.Fujiwara, S.Kumashiro,
R.Matsumiya, M.Ota, D.Shinojima, H.Tanaka, T.Yasuno, S.Nakajima, T.Suzuki, K.Yoshida,
K.Muranaka, T.Maemura, A.Chiba, Y.Utsuno, M.Fukuda, K.Tanaka, I.Tanihata, Y.Nojiri, T.Minamisono,
J.R.Alonso, G.F.Krebs, T.J.M.Symons, Measurement of the spin and magnetic moment of 23 Al,
Physical Review C, 74, 021301 (R) (2006).
5. T.Yamaguchi, T.Ohnishi, T.Suzuki, F.Becker, M.Fukuda, H.Geissel, M.Hosoi, R.Janik, A.Kelic,
K.Kimura, S.Mandel, G.Münzenberg, S.Nakajima, T.Ohtsubo,
A.Ozawa, A.Prochazka, M.Shindo, B.Sitar, P.Strmen, T.Suda, K.Sümmerer, K.Sugawara, I.Szarka,
M.Takechi, A.Takisawa, and K.Tanaka, Production cross-sections of isotopes formed by fragmentation of ∼1 A GeV 80 Kr beam; Physical Review C, 74, 044608 (2006).

53

6. Z.Elekes, Zs.Dombradi, A.Saito, N.Aoi, H.Baba, K.Demichi, Zs.Fulop, J.Gibelin, T.Gomi,
H.Hasegawa, N.Imai, M.Ishihara, H.Iwasaki, S.Kanno, S.Kawai, T.Kishida, T.Kubo, K.Kurita,
Y.Matsuyama, S.Michimasa, T.Minemura, T.Motobayashi, M.Notani, T.Ohnishi, H.J.Ong, S.Ota,
A.Ozawa, H.K.Sakai, H.Sakurai, S.Shimoura, E.Takeshita, S.Takeuchi, M.Tamaki, Y.Togano,
K.Yamada, Y.Yanagisawa, and K.Yoneda, Proton inelastic scattering studies at the borders of
the “island inversion”: The 3 0, 31Na and 33,34 Mg case, Physical Review C, 73, 044314 (2006).
7. Zs.Dombradi, Z.Elekes, A.Saito, N.Aoi, H.Baba, K.Demichi, Zs.Fulop, J.Gibelin, T.Gomi,
H.Hasegawa, N.Imai, M.Ishihara, H.Iwasaki, S.Kanno, S.Kawai, T.Kishida, T.Kubo, K.Kurita,
Y.Matsuyama, S.Michimasa, T.Minemura, T.Motobayashi, M.Notani, T.Ohnishi, H.J.Ong, S.Ota,
A.Ozawa, H.K.Sakai, H.Sakurai, S.Shimoura, E.Takeshita, S.Takeuchi, M.Tamaki, Y.Togano,
K.Yamada, Y.Yanagisawa, and K.Yoneda, Vanishing N=20 Shell Gap: Study of excited Statesin 27,28 Ne, Physical Review Letters, 96, 182501 (2006).
8. T. Kawabata, H. Akimune, H. Fujita, Y. Fujita, M. Fujiwara, K. Hara, K. Hatanaka, M. Itoh,Y. Kanada-En’yo, S. Kishi, K. Nakanishi, H. Sakaguchi, Y. Shimbara, A. Tamii, S. Terashima,
M. Uchida, T. Wakasa, Y. Yasuda, H.P. Yoshida and M. Yosoi 2α+t cluster structure in 11 B,
Physics Letters B 646, p6-11, 2007
9. B.K. Nayak, U. Garg, M. Hedden, M. Koss, T. Li, Y. Liu, P.V.Madhusudhana Rao, S. Zhu, M.
Itoh, H. Sakaguchi, H. Takeda, M. Uchida, Y. Yasuda, M. Yosoi, H. Fujimura, M. Fujiwara, K.
Hara, T. Kawabata, H. Akimune and M.N. Harakeh, ”Bi-modal” isoscalar giant dipole strengthin 58 Ni, Physics Letters B 637, p43-47, 2006
10. S.Y. Wang, Y.Z. Liu, T. Komatsubara, Y.J. Ma, Y.H. Zhang, Candidate chiral doublet bands inthe odd-odd nucleus Cs-126, Physical Review C 74 (1) 017302 JUL (2006)ATOMIC AND SOLID STATE PHYSICS, AND CLUSTER SCIENCE

11. S. Tomita, J.U. Andersen, H. Cederquist, B. Concina, O. Echt, J.S. Forster, K. Hansen, B.A.
Huber, P. Hvelplund, J. Jensen, B. Liu, B. Manil, L. Maunoury, S.B. Nielsen, J. Rangama, H.T.
2−
Schmidt, and H. Zettergren, “Lifetimes of C2−
60 and C70 dianions in a storage ring” J. Chem.

Phys. 124, (2006) 024310(1-9)
12. B. Concina, P. Hvelplund, A.B. Nielsen, S. Brøndsted Nielsen, J. Rangama, B. Liu, S. Tomita,“Formation and stability of charged amino acid clusters and the role of chirality”, J. Am. Soc.
Mass Spec. 17, (2006) 275-279
13. H. Zettergren, P. Reinhed, K. Støchkel, H.T. Schmidt, H. Cederquist, J. Jensen, S. Tomita, S.B.
Nielsen, P. Hvelplund, B. Manil, J. Rangama, B.A. Huber, “Fragmentation and ionization of
C70 and C60 by slow ions of intermediate charge”, Eur. Phys. J. D 38, (2006) 299-306

5414. A.V. Streletskiy, P. Hvelplund, S.B. Nielsen, B. Liu, S. Tomita, A.A. Gryunkov, O.V. Boltalina,“Differences in electronic properties of fluorinated and trifluoromethylated fullerenes revealedby their propensity for dianion formation”, J. Chem. Phys. 124, (2006) 144306(1-4)
15. T. Kaneko, H. Kudo, S. Tomita, R. Uchiyama, “Secondary electron emission from graphite
induced by MeV/atom carbon cluster impacts”, J. Phys. Soc. Jpn. 75, (2006) 034717(1-6)
16. O. Kamalou, B. Manil, J. Rangama, H. Lebius, B.A. Huber, S. Tomita, S. Broendsted Nielsen,
P. Hvelplund, J. Jensen, H.T. Schmidt, H. Zettergren, H. Cederquist, “Fullerene collisions andclusers of fullerenes”, Int. J. Mass Spectrom. 252, (2006) 117-125
17. B. Concina, S. Tomita, N. Takahashi, T. Kodama, S. Suzuki, K. Kikuchi, Y. Achiba, A. Gromov,
J.U. Andersen, P. Hvelplund, “Delayed ionization of C76 ”, Int. J. Mass Spectrom. 252, (2006)
96-99
18. H. Kudo, W. Iwazaki, R. Uchiyama, S. Tomita, K. Shima, K. Sasa, S. Ishii, K. Narumi, H.
Naramoto, Y. Saitoh, S. Yamamoto and T. Kaneko, “Energy Spectra of Electrons Induced by
MeV Atom Clusters”, Japanese Journal of Applied Physics, 45, No. 22, 2006, pp. L565-568.
19. S. Tomita, S. Yoda, R. Uchiyama, S. Ishii, K. Sasa, T. Kaneko, H. Kudo, “Nonadditivity of
convoy- and secondary-electron yields in the forward-electron emission from thin carbon foils
under irradiation of fast carbon-cluster ions”, Phys. Rev. A 73 (2006) 060901(R) (1-4).
20. B. Liu, P. Hvelplund, S.B. Nielsen, and S. Tomita, “Photodissociation of singly charged oligonuleotide
cations: Arrhenius parameters and identification of nonstatistical processes”, Phys. Rev. A 74,(2006) 052704 (1-6)
21. K. Shibata, Y. Sasaki, M. Kishimoto, H. Yanagihara, E. Kita, Magnetic Moment and Anisotropyof Iron Nitride Fe16 N2 Nanoparticles, J. Magn. Soc, Jpn. 30, No.5, 501-504 (2006)
22. Y. Toyota, H. Yanagihara, E. Kita. Interlayer Exchange Coupling through MgO in Epitaxial
Fe3 O4 /MgO/Fe(001) Trilayers, J. Magn. Soc, Jpn. 31, No.2 85-88, (2007)
23. T. Koyano T. Nomiyama, N. Kanoh, H. Numata, T. Ohba, E. Kita, H. Ohtsuka, Magnetizationof α 0 -iron nitride produced through the fcc → bct martensitic transformation in high magnetic
field, J. Appl. Phys., 100 033906-5 pages, (2006)
24. H. Yanagihara, M. Hasegawa, E. Kita, Y. Wakabayashi, H. Sawa and K. Siratori, Iron Vacancy Ordered γ-Fe2 O3 (001) Epitaxial Films: The Crystal Structure and Electrical Resistivity,
J. Phys. Soc. Jpn., 75, No. 5 (2006) 054708-p5
25. Tomohiro Ikeda and Masashige Onoda, Structural and electronic properties of the triangularlattice system Nax CoO2 , Journal of Physics: Condensed Matter 18, 8673-8682 (2006)
26. Masashige Onoda and Tomohiro Ikeda, Modulated and unmodulated structures, and the transport mechanisms in the triangular lattice system Nax CoO2 with x ' 0.48, 0.58 and 0.65, Journalof Physics: Condensed Matter 19, 186213 (14pp) (2007)

55

ION BEAM ANALYSIS AND APPLICATION

27. Kotaro Bessho, Hiroshi Matsumura, Taichi Miura, Qingbin Wang, Kazuyoshi Masumoto, Takeshi
Matsuhiro, Yasuo Nagashima, Riki Seki, Tsutomu Takahashi, Kimikazu Sasa and Keisuke
Sueki, AMS analysis of 36 Cl induced in concrete of accelerator facilities, Radiochim. Acta
94, 801-805, 2006.
28. M. Kurosawa, K. Shima, S. Ishii, K. Sasa, Trace element analysis of fused whole-rock glasses
by LA-ICP-MS and PIXE, Geostandards Newsletter: The Journal of Geostandards and Geoanalysis, 30, 237-245, (2005).
29. T. Nakajima and M. Kurosawa, Rare-element mineralogy of the Uzumine granitic pegmatite,
Abukuma mountains, northeastern Japan, Can. Mineral. 44, 31-44, (2006).
30. Y. Nagashima, R. Seki, T. Matsuhiro, T. Takahashi, K. Sasa, T. Usui, K. Sueki, 36 Cl Measurements in Japan, ”Reassessment of the Atomic Bomb Radiation Dosimetry for Hiroshima andNagasaki-Dosimetry System 2002”, Report of the Joint US-Japan Working Group, (Japaneseversion), Chapter 8, Part F, pp.567-572, The Radiation Effects Research Foundation, (2006).
31. T. Komatsubara, K. Sasa, H. Ohshima, H. Kimura, Y. Tajima, T. Takahashi, S. Ishii, Y. Yamato,
M. Kurosawa, K. Furuno, Hydrogen Content in Granite, ”Reassessment of the Atomic Bomb
Radiation Dosimetry for Hiroshima and Nagasaki-Dosimetry System 2002”, Report of the Joint
US-Japan Working Group, (Japanese version), Chapter 10, Part E, pp.764-768, Radiation Effects Research Foundation, (2006).
32. T. Komatsubara, K. Sasa, K. Okumoto, S. Ishii, Y. Yamato, K. Satou, K. Furuno, M. Kurosawa,
Development of ERCS hydrogen analysis for melt inclusions in erupted magmatic samples,
Nucl. Instrum. and Methods B, 251 (2006) 237-245.
33. K. Awazu, C. Rockstuhl, M. Fujimaki, N. Fukuda, J. Tominaga, T. Komatsubara, T. Ikeda,
T. Ohki, High sensitivity sensors made of perforated waveguides, OPTICS EXPRESS Vol.15,
No.5, 2592-2597 March (2007).
34. K. Awazu, X. Wang, M. Fujimaki, T. Komatsubara, T. Ikeda, Y. Ohki, Structure of latent tracks
in rutile single crystal of titanium dioxide induced by swift heavy ions, Journal of Applied
Physics 100, 044308 Aug (2006)

56

6.2 International conferences

1. Akira Ozawa, Reaction cross sections of unstable nuclei The sixth China-Japan Joint Nuclear
Physics Symposium 2006, 5/16-20, Shanghai, China
2. I. Sugai, Y. Takeda, M. Oyaizu, H. Kawakami, S.Ishii, K. Sasa and K. Shima, First Result ofTarget Preparation by a HIVIPP Method in High Pressure Higher than 1 Atm, The 23rd World
Conference of the International Nuclear Target Development Society (INTDS) in TSUKUBA,
Japan. Tsukuba Epochal InternationalCongress Centerat Tsukuba, October 16 - 20, 2006.
3. Kimikazu Sasa, Yasuo Nagashima, Yuki Tosaki, Yuki Matsushi, Michiko Tamari, Tsutomu
Takahashi, Ben Hu Zhou, Keisuke Sueki, Kotaro Bessho, Hiroshi Matsumura, Kazuho Horiuchi, Yasuyuki Shibata and Hideaki Motoyama, Preliminary results of 36 Cl measurement in an
ice core retrieved from the Dome Fuji station by the Tsukuba AMS system, The 9th symposium of Japanese AMS society, Prospects for the New Frontiers of Earth and Environmental
Sciences, 20, 21 October 2006, Takeda Hall, The University of Tokyo.
4. M. Nakazumi, H. Yanagihara and E. Kita, ”Tunnelling Magnetoresistance with NaCl Barriers”,
17P-5,19th International Colloquium on Magnetic Films and Surfaces, Sendai, August 14-18,
2006
5. Y. Toyoda, H. Yanagihara, E. Kita, T. Taniyama, ”Interlayer Exchange Coupling through Insulator in Epitaxial Fe3 -O4 /MgO/Fe Trilayers”, 15P-15, 19th International Colloquium on Magnetic Films and Surfaces, Sendai, August 14-18, 2006
6. E. Kita, K. Shibata, H. Yanagihara, Y. Sasaki, M. Kishimoto, ”Magnetic Properties of CoreShell Type Fe16N2 Nanoparticles”, PSTh-L-420, International Magnetism ConferenceICM2006Kyoto,2006 August
7. M. Hasegawa, H. Yanagihara, Y. Toyoda, E. Kita and L. Ranno, ”ELECTRICAL AND MAGNETIC PROPERTIES OF γ-Fe2 O3 EPITAXIAL FILMS”, PSTu-I-356, International Magnetism ConferenceICM2006Kyoto, 2006 August57

7. THESES
Ph. D. Theses
Shingo Sakai

Measurement of electron azimuthal anisotropy and implications√
for heavy quark flow in Au+Au collisions at sNN = 200 GeVTomohiro Ikeda

Crystal structures and electronic properties of the triangular latticesystem Nax CoO2

M. Sc. Theses
Yoshimasa Ikeda

Development of Reaction Plane Detector for RHIC-PHENIX

Rei Tanabe

Measurement of Elliptic Flow of Φ-meson atcollisions at RHIC-PHENIX

Masanori Narisawa

Performance Evaluation of Multigap Resistive Plate Chamber witha Monte Calro Simulation

Takahumi Niita

Measurements of Quantum Mechanical Two Particle Interference√in sNN = 200GeV Au+Au collision at RHIC-PHENIX

Yusuke Tomita

Measurements of Directed and Elliptic Azimuthal Anisotropy in√
sNN = 200GeV Au+Au Collision at Extremely Forward Rapidity Region

Yuta Toyoda

Magnetic properties and electronic conduction in Fe3−δ O4 /MgO/Fe
single crystal multilayers

Takuya Nishimura

Electronic energy transfer of energetic cluster ions in solids

So YodaDevelopment of electrostatic ion beam trap

Yuji Kikuchi

Synthesis and the electronic properties in the triangular lattice system
HCoO2

Akira Sasaki

Crystal structure and the electronic properties in the Li1+x V3 O8
insertion electrodeHiroyuki Mishiba

Evaluation of magnetron sputtering gas aggregation cluster sourcewith DSMC method

Toshio Sugaya

Sulfuration mechanism of gold cluster cation

Satoshi Igarashi

Developement of JAVA GUI for beam simulator MOCADI

Kanako Yamaguchi

Storage ring for mass measurement of unstable nuclei

Akira Komdo

Molecular dynamics calculation for hydrogen hydrate

58√
sNN =200GeV Cu+Cu

8. SEMINARS
Date
2005

Title and Speaker

May

10

The high baryon density CBM experiment and other QCD related research activities
at the future FAIR facility in Germany
Claudia Hoehne (GSI)

May

31

Implications for charm quark collectivity via electron measurement in Au + Au√
collisions at sNN = 200 GeVSingo Sakai (Univ. of Tsukuba)

Oct.

30

The role of Ions in Particle Nucleation
Jens Olaf Pepke Pedersen (Danish National Space Center)

Nov.

22

The AMS measurement and it’s application in CIAE
He Ming (CIAE)

Dec.

13

Development of Reaction Plane Detector for RHIC-PHENIX
Yoshimasa Ikeda (Univ. of Tsukuba)

Dec.

20

Measurement of Elliptic Flow of Φ-meson atcollisions at RHIC-PHENIX
Rei Tanabe (Univ. of Tsukuba)

Dec.

20

Evaluation of magnetron sputtering gas aggregation cluster sourcewith DSMC method
Hiroyuki Mishiba (Univ. of Tsukuba)

Dec.

27

Measurement of electron azimuthal anisotropy and implications√
for heavy quark flow in Au+Au collisions at sNN = 200 GeV
Shingo Sakai (Univ. of Tsukuba)

59√
sNN =200GeV Cu+Cu

2007
Jan.

10

Performance Evaluation of Multigap Resistive Plate Chamber witha Monte Calro Simulation
Masanori Narisawa (Univ. of Tsukuba)

Jan.

10

Sulfuration mechanism of gold cluster cation
Toshio Sugaya (Univ. of Tsukuba)

Jan.

17

Developement of JAVA GUI for beam simulator MOCADI
Satoshi Igarashi (Univ. of Tsukuba)

Jan.

24

Measurements of Quantum Mechanical Two Particle Interference√in sNN = 200GeV Au+Au collision at RHIC-PHENIX
Takahumi Niita (Univ. of Tsukuba)

Jan.

24

Storage ring for mass measurement of unstable nuclei
Kanako Yamaguchi (Univ. of Tsukuba)

Feb.

31

Measurements of Directed and Elliptic Azimuthal Anisotropy in√
sNN = 200GeV Au+Au Collision at Extremely Forward Rapidity Region
Yusuke Tomita (Univ. of Tsukuba)

Feb.

31

Molecular dynamics calculation for hydrogen hydrate
Akira Kondo (Univ. of Tsukuba)

March

1

Molecular wave function can not be expressed by atomic wave fucntion
Yoshiyuki Kawazoe (Tohoku Univ.)

60

9.

SYMPOSIA
Progress of nuclear reaction analysis
24 November, 2006
Room C305, Tandem Accelerator Complex,
Research Facility Center for Science and Technology, University of Tsukuba
1. Oppenheimer-Phillips process with CDCC method : Y. Aoki (Univ. of Tsukuba)
2. Sub-Coulomb barrier effect of 118 Sn(d,p) reaction : M. Iijima (Univ. of Tsukuba)
3. Review and perspectives of Continuum-Discretized Coupled Channel method : K. Ogata (Kyushu
Univ.)
4. Nonlocal folding optical potential : Y. Iseri (Chiba Keizai College)
5. Nuclear reaction study for astrophysics : S. Kubono (CNS)
6. Theoretical study for low energy reactions, 6 Li(d,p0 )7 Li and 6 Li(d,α)4 He : M. Tanifuji (Hosei
Univ.)
7. Resonant states in a nuclear reaction : K. Kato (Hokkaido Univ.)
8. Nuclear reaction and computer science : K. Yabana (Univ. of Tsukuba)
9. Deuteron breakup and charge exchange reaction : H. Okamura (Nagano National College ofTechnology)61

New evolution toward to an interdisciplinary use of the heavy ion beams produced by a multitandem accelerator system -Tendency and Results of the UTTAC Research Works16 March, 2007
Room C305, Tandem Accelerator Complex,
Research Facility Center for Science and Technology, University of Tsukuba
1. The UTTAC middle term objectives and research plans : Y. Nagashima (Univ. of Tsukuba)
2. Status of the Tsukuba AMS system and 36 Cl measurements of the Fuji dome ice core sample
at the Antarctica : K. Sasa (Univ. of Tsukuba)
3. Measurements of 10 Be and 26 Al in the old environmental samples -As a search of an index for
study of a fluctuation of comic ray intensity or dating- : K. Horiuchi (Hirosaki Univ.)
4. The assessment for thermal neutron radiation on a concrete shielding of an accelerator facility
by mean of 36 Cl-AMS measurement : K. Bessho (KEK)
5. Study of the fluid inclusions in a granite sample by mean of PIXE measurement : M. Kurosawa(Univ. of Tsukuba)
6. Reassessment of the Atomic Bomb Radiation Dosimetry for Hiroshima and Nagasaki -Dosimetry
System 2002- : M. Hoshi (Hiroshima Univ.)
7. Status report of hydrogen analysis by proton-proton elastic recoil coincidence spectrometry :T. Komatsubara (Univ. of Tsukuba)
8. Status of nuclear studies and future plans at UTTAC : A. Ozawa (Univ. of Tsukuba)
9. Basic and application physics with re-accelerated short lived radio isotope beam : H. Miyatake(KEK)
10. Application to a nano-photonics field at the UTTAC : K. Awazu (National Institute of Advanced
Industrial Science and Technology)
11. A challenge to a world record stripper foil with an ultra-super long life time in a charge exchange use : I. Sugai (KEK)
12. A study of a solid electron excitation process by an irradiation of a high energy cluster ion : S.
Tomita (Univ. of Tsukuba)
13. Interdisciplinary approaches by an accelerated ion beam : H. Kudo (Univ. of Tsukuba)62

10. LIST OF PERSONNEL
Tandem Accelerator Complex
Y. Nagashima
T. Komatsubara
K. Sasa
S. Ishii
H. Kimura
H. Oshima
Y. Tajima
T. Takahashi
Y. Yamato
Y. Matsushi
Y. Tagishi
M. MoroDirector, Professor
Assistant Professor
Assistant Professor
Mechanical Engineer
Computer Engineer
Electric Engineer
Mechanical Engineer
Electric Engineer
Electric Engineer
Research Fellow
Technical Assistant
Administrative Stuff

Research Members
Inst. of Physics
Y. AokiI. AraiT. Komatsubara
Y. Miake
Y. YasudaInst. of Applied Physics
K. Akimoto
E. Kita
A. Uedono
H. Yanagihara
Inst. of Material Science
J. Fukuda
H. Ikeda
H. Tanimoto
Inst. of Geoscience
M. Kurosawa

T. Chujo
M. Onoda

S. Esumi
A. Ozawa

S. Katoh
K. Sasa

H. KudoT. Makimura

N. Tomita

T. Koyano

H. Mizubayashi

H. Suzuki

M. Iijima
M. Nakazumi
K. Takao

M. Konno
M. OkaH. TokanoN. TaseInst. of Chemistry
K. SuekiInst. of Basic Medical Science
Y. Nagashima
Graduate Students
Doctoral Degree Programs of Pure and Applied Science
H. Arai
Zhou Benhu
M. Hashimoto
M. Kubo
H. Masui
K. MikiJ. Sawahata
J.W. Seo
M. Shimomura
N. Yagi

63

Master’s Degree Programs of Pure and Applied Science
T. Ebisawa
K. Ebisu
J. Hagiwara
S. Igarashi
Y. Ikeda
T. Ishikawa
H. Kasai
Y. Kikuchi
A. Kondo
M. Minakawa
H. Mishiba
Y. Mizuguchi
T. Nishimura
T. Moriguchi
Y. Odajima
A. Sasaki
T. SatoT. Sugaya
R. Tanabe
Y. Tomita
Y. Toyota
D. Yoshioka
Master’s Degree Programs of Education
T. Kawamata

Y. Hashizume
K. ItoT. Maekoya
M. Narisawa
K. Okumoto
T. Takahashi
K. Watanabe

T. HoyaS. Kanda
K. MikiT. Niida
W. Onoda
Y. Toyota
S. YodaH. Funagi
Y. Saito
N. Shiobara
S. Tsunegi
S. Yamaguchi

I. GotoD. Sakata
T. Suzuki
A. Onishi

K. Yamaguchi

Doctoral Degree Programs of Life and Environmental Sciences
Y. Tosaki
Undergraduates
H. Aizawa
R. Inaba
M. SanoY. Suzuki
N. Onishi

S. Amano
D. Inomata
Y. SatoS. Takahashi
T. WakiM. Fujieda
M. Murakami
N. Seya
M. TamariK. Yamada64

Scientific Guests and Fellows
K. Awazu
M. Fujimaki
T. Ikeda
S.J. Yu
H. Aiba
K. Sugimoto
Y. Koganezawa
J. Watanabe
T. Miura
K. Bessho
H. Matsumura
K. Masumoto
I. SugaiY. Takeda
M. Oyaizu
H. Kawakami
T. Hayakawa
T. Shizuma
T. Ohura
M. Yamazaki
H. Hashizume
M. Ebihara
J. AsaiR. Ichimiya
K. Kurita
M. Kawashima
K. Sakashita
N. Okumura

AIST
AIST
Waseda Univ.
Waseda Univ.
Waseda Univ.
Waseda Univ.
Waseda Univ.
Tokyo Univ.
KEK
KEK
KEK
KEK
KEK
KEK
KEK
KEK
JAEA
JAEA
Tokyo Metropolitan Univ.
Tokyo Metropolitan Univ.
Tokyo Metropolitan Univ.
Tokyo Metropolitan Univ.
RIKEN
RIKEN
Rikkyo Univ.
Rikkyo Univ.
Tokyo Institute of Technology
Nagano College of Technology

65