| Project/Area Number |
02650461
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | Tokyo Gakugei University |
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Principal Investigator |
KANAZAWA I. Tokyo Gakugei Univ. Education, Assoc. Prof., 教育学部, 助教授 (00134768)
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| Co-Investigator(Kenkyū-buntansha) |
IWASHITA T. Tokyo Gakugei Univ. Education, Prof., 教育学部, 教授 (00016081)
MURAKAMI H. Tokyo Gakugei Univ. Education, Prof., 教育学部, 教授 (30011000)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | intense slow positron beam / an electron linac / magnetic tield / brightness enhancement / detects / multilayered materials / S parameter / trapped / RHEPD / Si(III) / 0 / 7ラウエ・ゾ-ン / 酸化物層 / HfーCu金属多層膜 / ストッピング・プロファイル / 低速陽電子 / モデレ-タ / 磁場型ビ-ム / 静電場型ビ-ム / アインツェル・レンズ / ズ-ム・レンズ / チャンネルプレ-ト |
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| Research Abstract |
A brightness enhanced intense slow positron beam has been obtained from an electron linac. The success of the present method in transporting the slow positron beam(SPB)through a magnetic field followed by efficient extraction to a field-free region using the "magnetic field splitter". The beam size is 0.5 mm in diameter at present, but it can be made much smaller by several improvements : better geometrical configuration of the stage of separation. from magnetic field and the optics of the brightness enhancement. Further improvements on this line are under way. The intensity of the SPB was measured at 1/10 of full power operation of the linac. At full power operation of the linac, which is avoided for the present simply because of the health physics reasons that the concrete shield between the irradiation room and the experimental room is not thick enough, it would be possible to obtain brightness enhanced positrons with an intensity of about 2 x 10^7 counts/sec.
By using this slow positron beam, performed measurements for defects in Cu-Hf multilayered materials. Three kinds of speciments, whose thickness (Cu 500A/Hf 500A), and thickness (Cu 1000A/Hf 1000A). The decrease of s parameter below about 1 keV reflects oxidized Hf layer less than 20 A. Furthermore these results show that the Hf layer contains many vacancy-like defects and thermalized most positrons are trapped in those defects.
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