| Project/Area Number |
18360450
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Nuclear engineering
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
YAMAZAKI Hiromichi Tohoku University, Cyclotron Radioisotope Center, Professor (00166654)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MATSUYAMA Shigeo Graduate School of Engineering, 大学院・工学研究科, Associate Professor (70219525)
KIKUCHI Yohei Graduate School of Engineering, 大学院・工学研究科, Assistant Professor (50359535)
|
|---|
| Project Period (FY) |
2006 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥12,420,000 (Direct Cost: ¥11,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2007: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2006: ¥8,000,000 (Direct Cost: ¥8,000,000)
|
|---|
| Keywords | nanobeam / PIXE / RBS / off-axis STIM / Chemical Form Analysis / 荷電粒子励起X線分光法(PIXE) / ラザフォード後方散乱法(RBS)- / 透過イオン分光法(STIM) / 黄砂 / イオンビーム分析 / 化学形態 |
|---|
| Research Abstract |
In this study, a nanobeam system has been developed for chemical state elemental analysis in samples under various environmental and biochemical conditions in the nanoscopic region. Combination of PIXE, RBS and off-axis STIM methods enabled simultaneous analysis for hydrogen to metal elements and revealed the chemical composition of the elements contained in the sample.
In order to improve the microbeam performance and decrease the beam spot size down to several tens nm with higher beam current, the terminal equipments and an acceleration tube of the Dynamitron accelerator were upgraded. The microbeam system was also improved. Parasitic field contamination from tungsten carbide slit chips and an annular Si surface barrier detector limited the beam spot size to 2×2μm^2. By replacing these components, the parasitic field contamination of the system was reduced and the performance of the microbeam system was remarkably improved. A measured beam spot size of 0.4×0.4μm^2 at a beam current of
… More
several tens of pA has been accomplished. The results obtained using the grid-shadow method show that a beam spot size of less than 0.4μm is obtainable in the low-current regime.
The nanobeam system was applied to analysis of yellow sand dust particles. The major elements of yellow sand dust particles are silicon, calcium, oxygen, carbon, and hydrogen, and exist in the form of oxide or carbonate. The ternary diagram of aluminum, silicon, and calcium shows the difference of the soil components of the Asian continent and Japanese islands. The correlation of calcium and chlorine is different for each Kosa event depending on the difference of transport to the Japanese islands. Yellow sand dust particles contain more sulfur and heavier elements such as manganese and zinc. These particles were transported from the Asian continent over industrial areas to Japan and might adsorb these elements by mixing with anthropogenic aerosols. These results were obtained by analyzing single aerosol particles and were not obtained using bulk analysis, which averages measurements over many particles. Single particle analysis of yellow sand dust will engender a better understanding of their formation process during transport.
The nonobeam system was also applied to characterization of steel corrosion. Thickness and elemental distribution of corrosion layer could be determined in the nanoscopic region. Corrosion progresses remarkably in the case of steels containing Cr less than 0.1wt%. Less
|
