| Project/Area Number |
21K14562
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 31010:Nuclear engineering-related
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| Research Institution | Osaka University |
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Principal Investigator |
EMPIZO MELVIN 大阪大学, レーザー科学研究所, 助教 (70796432)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Project Status |
Granted (Fiscal Year 2021)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2023: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2022: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2021: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
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| Keywords | Optical material / Crystal growth / Gamma ray / Irradiation / Spectroscopy |
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| Outline of Research at the Start |
Optical windows form a vital part of the plasma diagnostic instruments and the remote inspection and maintenance systems of laser fusion reactors. However, gamma rays produced during or after the fusion reaction could be detrimental to any optical window material due to the fact that ionizing gamma rays can cause bulk and surface damages. In this regard, this research aims to develop Kyropoulos-grown SrB4O7 (SBO) single crystals as gamma-ray radiation-resistant optical window materials.
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| Outline of Annual Research Achievements |
SrBrO7 (SBO) single crystals have been successfully fabricated by Kyropolous growth method using different growth parameters including precursor purity and growth rate. The as-grown crystals were subsequently characterized using analytical techniques such as optical microscopy, vacuum ultraviolet (VUV) transmittance spectroscopy, and x-ray diffraction spectroscopy. Laser-induced damage investigations have also been performed through single-shot and multi-shot irradiation. High-quality, b-axis-oriented SBO single crystals with 100-mm dimensions (large), up to 80 % VUV transmittances, and high deep ultraviolet (DUV) laser-induced damage resistance have been successfully prepared by Kyropolous growth method. These results have already been submitted for publication with one paper just recently been accepted and the other under review.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The research aim of fabricating more than 60-mm SBO crystals and one out of three scientific publications have been achieved. The laser-induced damage of the Kyropolous-grown crystals has also been investigated under single-shot and multi-shot irradiation.
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| Strategy for Future Research Activity |
In the next fiscal year, the Kyropoulos-grown SBO single crystals will be irradiated with gamma rays from a cobalt-60 source. The irradiation will be carried out with different absorbed doses, and the crystals' structural and optical properties will be evaluated using a variety of characterization techniques. Gamma-ray irradiation effects on the crystals properties will be determined by comparing the results before and after irradiation. The changes in the crystal properties will likewise be examined in relation to the absorbed doses. Detailed analysis is crucial in understanding the damage formation mechanisms in order to improve the Kyropoulos growth method for the fabrication of radiation-resistant SBO single crystals.
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