1994 Fiscal Year Final Research Report Summary
STUDIES ON MICROSCOPIC STRUCTURES FOR PRODUCTION/DISAPPEARANCE MECHANISMS OF LASER-INDUCED PLASMA AND DYNAMICS DURING LASER-INDUCED DISCHARGE
| Project/Area Number |
05402038
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | FUKUOKA INSTITUTE OF TECHNOLOGY (1994)
Kyushu Tokai University (1993) |
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Principal Investigator |
AKAZAKI Masanori FUKUOKA INSTITUTE OF TECHNOLOGY PRESIDENT, 学長 (30037676)
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| Co-Investigator(Kenkyū-buntansha) |
OKANO Daisuke KYUSHU TOKAI UNIVERSITY,SCHOOL OF ENGINEERING ASSOCIATE PROFESSOR, 工学部, 助教授 (00169129)
SONODA Yoshito KYUSHU TOKAI UNIVERSITY,SCHOOL OF ENGINEERING PROFESSOR, 工学部, 教授 (90117143)
TSUTSUMI Tadahito KYUSHU TOKAI UNIVERSITY,SHCOOL OF ENGINEERING PROFESSOR, 工学部, 教授 (60248606)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Laser Induced Lightning / Discharge in Atmospheric Air / Laser Diagnostics / Plasma / Electron Temperature / Electron Density |
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| Research Abstract |
The aim of this research is to find the successful conditions for laser-induced lightning, by understanding (1) the mechanism of ionization by excimer alsers in pure gases and (2) the formation mechanism of plasma produced by CO_2 laser in atmospheric air and (3) processes during laser-induced dicharge. For (1), experiments were done in different kind of ambient gas (air, N_2, O_2 of 100-1000mb in pressure) under an uniform DC electric field using Rogowski electrodes. Through electrical and optical measurements, it was found that oxygen molecules play an important role in characteristics of a laser-induced discharge. For (2) and (3), flashover induction experiments were perfomed for two types of long-gap electrode configurations, plate to rod and plate to plate, with a 50 J TEA CO_2 laser. From the flashover voltage characteristics and interferometric optical measurements on laser-induced plasma, it was found that the delay time for minimum V_<50> defined as 50% flashover voltage, measured from a laser incidence exists in the range of 50 to 200 mus, in laser-induced discharge of plate to rod, the value of V_<50> for negatively biased on the plate are larger than the case of positively biased, and laser-induced discharge does not occur on the surface of shock wave but relates on the low density region in the plasma produced by the laser.
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Research Products
(16 results)
