| Project/Area Number |
06680456
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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 |
プラズマ理工学
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| Research Institution | The Institute of Physical and Chemical Research (RIKEN) |
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Principal Investigator |
AMEMIYA Hiroshi The Institute of Physical and Chemical Research senior Scientist, プラズマ物理研究室, 副主任研究員 (60087426)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Negatibe Ion / Optical Response / Laser Light / Plasma / D-Layr / Photodetachment / Probe / Oxygen / レーザー |
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| Research Abstract |
The aim of the present investigation is to perform experiments in a hollow cathode disharge and a parallel plate (capacitive) radio freqency (RE) discharge in oxygen by injecting a pulsed YAG laser light into them to observe the transient phenomena like the excitation of ion acoustic waves caused by the photodetachment of oxygen negative ions and the recombination by electron attachment.These have been able to prove experimentally.
In the fiscal year of 1995, the negative ion plasma has been irradiated by photographic strobo light and flush lamp light and the above phenomena have been investigated in the case of diffused lights.Essentially, no difference can be expected between coherent and diffused lights on the photogalvanic effect if the light intensity is of the same order.Experimental reslts, however, have shown that no substantial effect of optogalvanic current occurs in the case of diffused lights and the simulation of the D-layr phenomenon by photodetachment could not be reproduced. A mechanism may be considered to be due to the necessity of light fucusing in the plasma which has a boundary.That is, the photodetached electrons should be confined in a narrow space in order not to diffuse towards the wall.
In relation to the above-mentioned effects, a theoretical work on the characteristics of the sheath in the negatibe ion plasma has been made.It has been found that the response of the sheath has a hysteresis effect inherently.This can also affect the optical response of the plasma.Furthermore, a rocket experiment on the mid-latitude D-layr has been made and the negatibe ion density and density ratio there could be measured.This was useful for considering the optical response of the D-layr.
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