| Project/Area Number |
08640519
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物理学一般
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| Research Institution | The Institute of Physical and Chemical Research (RIKEN) |
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Principal Investigator |
KIMURA Kazuie Cyclotron, The Institute of Physical and Chemical Research(Riken), senior Scientist, サイクロトロン研究室, 先任研究員 (40087614)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | electron-hole plasma / high-density excitation / α-alumina / luminescence / heavy ions / track effect / decay / time-resolved spectrum / ワイドバンドギャッブ結晶 / イオン照射 / 電子-空孔プラズマ / 絶縁体中プラズマ / 極短寿命発光 / 時間分解発光スペクトル / LET依存発光 / 励起子コンプレクス / 緩和励起子 / 発光スペクトル / 誘導輻射 / 高密度励起効果 / 重イオン照射効果 / オージェフリー発光 / 高速decay測定 / 内殻励起子 / 緩和励起子の交換相互作用 / 単一イオン単一光子時間相関法 / 凝縮希ガスのブラック曲線 |
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| Research Abstract |
Our technique for fast decay measurements-single ion and single photon coincidence(SISP) was further developed to obtain a resolution of 85 ps (the fastest of the similar equipment's reported for ion irradiation so far) and also to take a time-resolved spectrum. As for its application to different fields, a detector of the SISP was installed into a TOF system and a new impurity analysis system was developed. Our results ale as follows.
A new ultra-short lived luminescence band was found in ion irradiated alumina crystals, which has not been found by laser and pulsed electron irradiation. This band has a peak around 340 nm a broad band-width of 2eV, and a short lifetime of 100 ps. Further experiments elucidated that the new band could be observed in a many kind of crystals like oxides, alkali and alkali-earth halides. Considering characteristics shown by the results, the super-linear dependence on excitation density, the temperature independence, a ultra short lifetime, and a broad band, it may be concluded that the electron-hole plasmas or complexes composed of the electron-hole pair and other excited states are formed. We assigned this new band due to luminescence associated with the relaxation of the electron-hole plasma. This finding may open and lead the study for ion-irradiation effects into new development and also make it possible to study the effect of high-density excitation and the plasma of the wide band-gap crystals.
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