JAEA-Review-2010-065.pdf:15.99MB - 日本原子力研究開発機構

More documents

Recommendations

Info

4-30 Observation of Heavy Ion Induced Transient Species in Water by Spectroscopic Technique M. Taguchi a) , Y. Sugo b) , S. Kurashima c) , A. Kimura a) and K. Hirota a) a) Environment and Industrial Materials Research Division, QuBS, JAEA, b) Division of Fuels and Materials Engineering, NSED, JAEA, c) Department of Advanced Radiation Technology, TARRI, JAEA Introduction High energy heavy ions induce unique irradiation effects, which are differ from those induced by low LET radiations, such as -rays or electron beam. These effects are induced by reactions of reactive species generated heterogeneously and densely around its trajectory in medium, and used as a new tool for the various basic and application studies for material and biological sciences. We decide water samples as a first target because it is the main component of living body, and radiation-induced reactions in water are well understood under low LET radiation. Hydroxyl(OH) radical is the most important species for reactions in water samples because of its high reactivity and formation yield. 1, 2) In a previous paper , we decided experimentally the formation yield of the OH radicals depending on the mass and energy of incident ions, and elapsed time just after irradiation. However, in order to understand the chemical reactions in the track in more detail, a time resolved spectroscopy is a good approach for observing radical behaviors. We constructed the highly sensitive transient absorption measurement system using pulsed heavy ions 3) from AVF cyclotron . The reactions caused by the OH radical were observed by using this measurement system. Experimental The aqueous sample solution was poured into the metallic cell and irradiated with the pulsed heavy ions in the atmosphere, and optical absorbance was measured in online. The number of heavy ions included in the pulse was evaluated by reading the electric charge received by Faraday cup that had been set in the vacuum in the upper-stream of the irradiation cell. The fine structure of the pulse was also evaluated by measuring the luminescence from a scintillator set at the sample position. The semiconductor light source or Xe lamp was used as a probe light source. The probe light passed the sample cell twice at the angle of 20 degree toward the beam axis by mirrors above and under the sample cell, and then was detected with Si photodiode. The cell has the thickness of 2 mm and 50-m glass windows on the top and bottom for preventing energy loss of the heavy ions and optical measurement. Results and discussion The absorption spectrum, which has a peak in the visible region by the heavy ion irradiation to aqueous potassium thiocyanate (KSCN) solution, was observed. This absorbance was assigned to (SCN) 2 - from spectrum structure. The well-known reaction between the OH radical and SCN - JAEA-Review 2010-065 Absorbance - 154 - LET eV/nm 20 10 20 10 0 0 0 1 2 3 4 5 Depth / mm 0.0004 0.0003 0.0002 0.0001 0 Energy / MeV 0 1000 2000 3000 4000 Time / s s s Fig. 1 Depth curves of energy and LET value of H ion in water(upper), and time profiles of absorbance at 447 nm for aqueous KSCN solution at each depth(lower). under low LET radiation is also observed by the heavy ion irradiation. In order to investigate energy or LET effects on radical behaviors, the incident energy was controlled by putting thin aluminum foils on the irradiation cell. Since H ion has 4 mm range in water, the absorbance measurements could be carried out for reactions occurred in the distinguished region, for example, plateau (○) and Bragg peak regions (◇) as shown in Fig. 1. The yield of the OH radical was estimated from the absorbance peak of (SCN) 2 - just after the pulsed heavy ion irradiation. The yield in the Bragg peak region was a fraction of that in the plateau region, and this LET dependence could be explained in terms of the track structure theory. References 1) M. Taguchi et al., Radiat. Res. 171 (2009) 254-263. 2) G. Baldacchino et al., Chem. Phys. Lett. 468 (2009) 275-279. 3) M. Taguchi et al., Radiat. Phys. Chem. 78 (2009) 1169-1174.
4-31 Stabilization of Measurement System of the Heavy Ion Beam Pulse Radiolysis Using Scintillator T. Kondoh a) , J. Yang a) , K. Kan a) , Y. Yoshida a) , H. Shibata b) , S. Kurashima c) and M. Taguchi d) a) ISIR, Osaka University, b) Faculty of Engineering, Kyoto University, c) Department of Advanced Radiation Technology, TARRI, JAEA, d) Eenvironment and Industrial Materials Research Division, QuBS, JAEA An ion-beam pulse radiolysis system with scintillators is being developed at TIARA facility to measure the initial process of ion-beam induced reactions in the microscopic tracks. This ion pulse radiolysis system had some problems that the measured light intensity was very unstable and the fluctuation could not be compensated by the reference. Therefore, the intensity of signal light was stabilized and the optimization of measuring the reference was carried out in last year. イオンビームを用いたがん治療など応用技術が、近年発展し、注目されている。これらは、高LET放射線である重イオンビームが、物質に入射した時の局所的高密度励起の効果を応用したものであり、今後の発展には、局所的高密度励起と後続の反応過程を解明する必要がある。パルスラジオリシスは、パルス的に照射した放射線により物質中に生成した活性種を光吸収などで観測する手法であるが、イオンビームの場合、エネルギー付与の空間構造の特異性などから測定システムの構築は非常に困難である。さらに、高密度励起により生成した活性種は、高速に反応するため、これを解明するにはナノ秒程度の時間分解能が必要である。我々は、シンチレータをビーム軸上の試料直前に置き、イオンビームによるシンチレータの発光を分析光として、試料中の高密度励起による活性種の光吸収を測定する方法を開発している。この手法では、分析光源と励起場所がイオンビームの飛跡上なので、トラック内の活性種測定と高時間分解能を同時に実現できる。サイクロトロンの重イオンビームは、通常数10ナノ秒のパルス間隔のため化学反応の観測は困難であるが、P チョッパーとSチョッパーを同時に高度に制御することにより、220 MeV C 5+ イオンビームのシングルパルス化に成功した。 HYポートに輸送されたビームは、サンプルセル上に設置されたシンチレータを通過した後、試料に入射して停止する。シンチレータ発光のうち試料を通過した光がフィルターで分光され光電子増倍管で検出される。光吸収測定には、それぞれの試料について光源光強度、照射時信号光強度、ビームノイズ、バックグラウンドの四つのデータが必要である。これまで、試料 Fig. 1 New stabilized measurement system of the heavy ion beam pulse radiolysis using scintillator with reference measurement. JAEA-Review 2010-065 - 155 - を変更する毎、更に一つのデータ取得中でも信号光強度が変動する問題があった。平均強度と位置の安定性が高いサイクロトロンのビームであるが、シングルパルス切り出し条件下では、ビーム強度や位置の変動が信号光に影響していると考え、試料を通過しないシンチレータ発光を測定し、光源光強度のリファレンスとして補正を試みたが、成功しなかった。この原因は、試料液面、サンプルセル、シンチレータの配置に独立性と再現性が低く、リファレンスが光源変動を反映していない事が原因と考えられる。この問題を解決するために、今年度は測定体系の安定化対策を行った。改良した測定装置体系をFig. 1に示した。従来の体系における測定の再現性の欠如は、縦型セルとシンチレータの非独立積層型配置が原因と考えられる。各素子の直線的配置はそのままに、石英サンプルセルを横向きに使用し、フリッパーマウントに固定することにより光路長は正確に一定となり、独立かつ再現性の高い配置に変更した。また、シンチレータはコリメーター下に固定し、フリッパーマウントにより独立かつ再現性高く設置した。コリメーター下流に設置することによりコリメーターを通過したイオンビームのみがシンチレータを発光させるのでリファレンスは正確に信号光を反映する。安定化対策の後、光源変動補正のために、リファレンス測定配置の最適化を行った。CaF 2(Eu)シンチレータを用い、信号光強度とリファレンス光強度の間の相関をFig. 2に示した。信号光強度とリファレンス光強度には比例関係があり、最適化した配置ではリファレンスによる光源光強度の補正が可能となった。 Fig. 2 Correlation between the signal (vertical axis) and the reference (horizontal axis).
Page 3 and 4:
JAEA-Review 2010-065 JAEA Takasaki
Page 5 and 6:
JAEA-Review 2010-065 PREFACE This r
Page 7:
JAEA-Review 2010-065 and pulsed hea
Page 10 and 11:
JAEA-Review 2010-065 1-23 Studies o
Page 12 and 13:
JAEA-Review 2010-065 3-24 Lethal Ef
Page 14 and 15:
JAEA-Review 2010-065 4-07 Fabricati
Page 16 and 17:
JAEA-Review 2010-065 5. Status of I
Page 18 and 19:
JAEA-Review 2010-065 1-13 Alpha-rad
Page 21 and 22:
1-01 Radiation Resistance of InGaP/
Page 23 and 24:
1-03 Evaluation of Soft Error Rates
Page 25 and 26:
1-05 Heavy-ion Induced Current in S
Page 27 and 28:
Total Ionizing Dose Tolerance of Si
Page 29 and 30:
1-09 Evaluation of Single Event Eff
Page 31 and 32:
Hydrogen Diffusion in a-Si:H Thin F
Page 33 and 34:
1-13 Alpha-radiolysis of Organic Ex
Page 35 and 36:
Study on Stability of Cs·Sr Solven
Page 37 and 38:
Irradiation Effect of Gamma-Rays on
Page 39 and 40:
1-19 Development of Radiation Resis
Page 41 and 42:
1-21 Alpha-Ray Irradiation Damage o
Page 43 and 44:
1-23 Studies on Microstructure and
Page 45 and 46:
1-25 Effect of Groundwater Radiolys
Page 47 and 48:
1-27 Simulation of Neutron Damage M
Page 49 and 50:
1-29 Irradiation Hardening in Ion-i
Page 51 and 52:
1-31 Preparation of Anion-Exchange
Page 53 and 54:
1-33 Radiation-Induced Graft Polyme
Page 55:
JAEA-Review 2010-065 2. Environment
Page 58 and 59:
2-02 Development of Zwitterionic Mo
Page 60 and 61:
Modification of Hydroxypropyl Cellu
Page 62 and 63:
The Recovery of Precious Metals Usi
Page 64 and 65:
2-08 ESR Study on Carboxymethyl Chi
Page 67 and 68:
JAEA-Review 2010-065 3. Biotechnolo
Page 69 and 70:
JAEA-Review 2010-065 3-28 Electron
Page 71:
JAEA-Review 2010-065 3-51 PET Studi
Page 74 and 75:
3-02 Mutagenic effects of He ion pa
Page 76 and 77:
3-04 Functional Analysis of Flavono
Page 78 and 79:
3-06 Generation New Ornamental Plan
Page 80 and 81:
3-08 Stability of Flower-colour Mut
Page 82 and 83:
3-10 JAEA-Review 2010-065 Effects o
Page 84 and 85:
3-12 Producing New Gene Resources i
Page 86 and 87:
3-14 Production of Soybean Mutants
Page 88 and 89:
Assessment of Irradiation Treatment
Page 90 and 91:
3-18 Effect of Different LET Radiat
Page 92 and 93:
3-20 JAEA-Review 2010-065 Fungicide
Page 94 and 95:
3-22 JAEA-Review 2010-065 FACS-base
Page 96 and 97:
3-24 Lethal Effects of Different LE
Page 98 and 99:
3-26 JAEA-Review 2010-065 Ion Beam
Page 100 and 101:
3-28 Electron Spin Relaxation Behav
Page 102 and 103:
3-30 Target Irradiation of Individu
Page 104 and 105:
3-32 Carbon-ion Microbeam Induces B
Page 106 and 107:
3-34 Biological Effects of Carbon I
Page 108 and 109:
3-36 Difference in Bystander Lethal
Page 110 and 111:
3-38 Analysis of Lethal Effect Medi
Page 112 and 113:
3-40 Irradiation with Carbon Ion Be
Page 114 and 115:
3-42 Expression of Two Gelsolins in
Page 116 and 117:
3-44 Analysis of Bystander Cell Sig
Page 118 and 119:
3-46 Quantitative Evaluation of Ric
Page 120 and 121: 3-48 Visualization of 107 Cd Accumu
Page 122 and 123: 3-50 Uniformity Measurement of Newl
Page 124 and 125: 3-52 Imaging and Biodistribution of
Page 126 and 127: 3-54 Improvement of Spatial Resolut
Page 128 and 129: 3-56 The Optimum Conditions in the
Page 130 and 131: 3-58 Evaluation of Cisplatin Concen
Page 132 and 133: 3-60 JAEA-Review 2010-065 Analysis
Page 134 and 135: 3-62 JAEA-Review 2010-065 Sensitivi
Page 136 and 137: JAEA-Review 2010-065 4-14 The Effec
Page 138 and 139: JAEA-Review 2010-065 4-39 Relations
Page 141 and 142: 4-01 Hydrogen Gasochromism of WO3 F
Page 143 and 144: 4-03 Synthesis of Single-Crystallin
Page 145 and 146: 4-05 Synergy Effects in Electron/Io
Page 147 and 148: Fabrication of Diluted Magnetic Sem
Page 149 and 150: 4-09 Gas Permeation Characteristics
Page 151 and 152: 4-11 Control of Radial Size of Poly
Page 153 and 154: 4-13 Behavior of N Atoms in Nitridi
Page 155 and 156: 4-15 JAEA-Review 2010-065 Annealing
Page 157 and 158: Low Temperature Ion Channeling of F
Page 159 and 160: 4-19 Radiation-Induced Electrical D
Page 161 and 162: 4-21 Study on Cu Precipitation in E
Page 163 and 164: 4-23 Evaluation of Fluorescence Mat
Page 165 and 166: 4-25 Evaluation of the ZrC Layer fo
Page 167 and 168: 4-27 Structure Analysis of K/Si(111
Page 169: 4-29 LET Effect on the Radiation In
Page 173 and 174: Systematic Measurement of Neutron a
Page 175 and 176: 4-35 Measurement of Neutron Fluence
Page 177 and 178: 4-37 Evaluation of the Response Cha
Page 179 and 180: 4-39 Relationship between Internucl
Page 181 and 182: 4-41 Analysis of Radiation Damage a
Page 183 and 184: 4-43 Positive Secondary Ion Emissio
Page 185 and 186: 4-45 JAEA-Review 2010-065 Ion Induc
Page 187 and 188: 4-47 Fabrication of Dielectrophoret
Page 189 and 190: 4-49 Fast Single-Ion Hit System for
Page 191 and 192: 4-51 Development of Beam Generation
Page 193: JAEA-Review 2010-065 5. Status of I
Page 196 and 197: Operation of the AVF Cyclotron T. N
Page 198 and 199: Operation of Electron Accelerator a
Page 200 and 201: 5-06 FACILITY USE PROGRAM in Takasa
Page 202 and 203: 5-08 Radioactive Waste Management i
Page 226 and 227:
Appendix 2 List of Related Patents
Page 230 and 231:
Appendix 4 Type of Research Collabo
Page 235:
表1.SI 基本単位基本量 SI
show all

JAEA-Review-2010-065.pdf:15.99MB - 日本原子力研究開発機構

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?