1993 Fiscal Year Final Research Report Summary
Development of Positron Mass-Production Method
| Project/Area Number |
03559004
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MOHRI Akihiro Kyoto Univ., Fac.of Integrated Human Studies, Prof., 総合人間学部, 教授 (10025926)
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| Co-Investigator(Kenkyū-buntansha) |
OKUDA Soichiro Mitsubishi Electric Corp.Central Res.Lab., Group Manager, 中央研究所, グループマネージャー
KAWASE Yoichi Kyoto Univ., Research Reactor Institute, Prof., 原子炉実験所, 教授 (60027448)
TANAKA Hitoshi Kyoto Univ., Fac.of Integrated Human Studies, Res.Assist., 総合人間学部, 助手 (90183863)
MICHISHITA Toshinori Kyoto Univ., Fac.of Integrated Human Studies, Res.Assist., 総合人間学部, 助手 (00166050)
YUYAMA Tetsumori Kyoto Univ., Fac.of Integrated Human Studies, Res.Assist., 総合人間学部, 助手 (90026815)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Slow positron / Positron production / LINAC / Pair creation / Converter / Moderator / Magnetic duct as / Solid film of gas atoms |
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| Research Abstract |
The research and development on positron mass-production by using a high current LINAC have been performed for three years. The following improvements in Production Efficiency of Low Energy Positrons have been obtained.
1. Efficient converter, named "Modular Photon-Positron Converter"(MPPC), form energetic photons to slow positrons were developed. This converter can enlarge the positron emitting surface of tungsten foils which emit slow positrons at bombardment of energetic photons, and also extract them by applying effective electric field. Experiments on the proof of the principle showed that MPPC works well and the production rate is in agreement of the estimation based on Monte-Carlo simulations using EGS4 code.
2. Efficient converter, named "Photon-Nonthermal Positron Converter"(PNPC), was developed. Extraction of positrons of low energy region can increase the net positron production efficiency dramatically. It was experimentally proved that the production rate per unit surface area of tungsten foil became 15-20 times that in the case of (1). The attained production rate during the LINAC beam pulse was 2 X 10^<13>[e^+/s] and the time averaged one for 100 pps reached 8 X 10^8[e^+/s], in spite of the used low LINAC beam energy as 30 MeV.This converter is very simple in structure and it can be fablicated easily.
3. Other developments in transportation of positrons with a magnetic duct and also in remoderation of them were made. The attained time averaged production rate of positrons below 6 eV was 3.3 X 10^7[e^+/s].
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