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Investigation on effects of quenching of Einstein A coefficient in plasmas

Research Project

Project/Area Number 04808004
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field プラズマ理工学
Research InstitutionNational Institute for Fusion Science

Principal Investigator

SATO Kuninori  NIFS, Associate Professor, 助教授 (70126861)

Co-Investigator(Kenkyū-buntansha) NARIHARA Kazumichi  NIFS, Associate Professor, 助教授 (90109356)
TAWARA Hiroyuki  NIFS, Associate Professor, 助教授 (90037797)
ODA Toshiatsu  Hiroshima Univ., Professor, 工学部, 教授 (60034550)
Project Period (FY) 1992 – 1993
Project Status Completed (Fiscal Year 1993)
Budget Amount *help
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥1,100,000 (Direct Cost: ¥1,100,000)
KeywordsTransition Probability / Atom, Molecular Process / Plasma Elementary Process / Recombining Process
Research Abstract

1) In order to investigate the claim : Quenching of Einstein A Coefficient in Plasmas which has been proposed by the Princeton Univ.group, we tried to measure the branching ratios of He I np^3P-2s^3S, 3s^3S (n=6,7,8,9,10) in low density plasmas (ne<10^<14> cm^<-3>), which enables us to measure the total line intensities without the problem of Stark broadening. Here, we used nonequilibrium recombining plasma, in order to observe the transitions from highly excited states.
As the result, changes of branching ratios up to 50% were observed. However, this result may not be directly attributed to the quenching spontaneous transition probabilities caused by the quantum electromagnetic effect. At present, an effect of level mixing at highly excited states is a candidate for a possbile mechanism on the changes of branching ratio.
2) According to a branching ratio between multiplet structures, it is generally demonstrated that the atomic branching ratio is a constant and does not depend on the population distribution among the upper sublevels, if the structures of lower levels are same.

Report

(3 results)
  • 1993 Annual Research Report   Final Research Report Summary
  • 1992 Annual Research Report

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Published: 1992-04-01   Modified: 2016-04-21  

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