1994 Fiscal Year Final Research Report Summary
Characterization of ultra high energy density plasma generated by a pinch discharge
| Project/Area Number |
05680385
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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 | Gunma University |
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Principal Investigator |
HIRANO Katsumi Dept.of Electronic Engineering, Gunma University, Professor, 工学部, 教授 (60008430)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Toshikazu Dept.of Electronic Engineering, Gunma University, Assistant, 工学部, 助手 (40143200)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Ultra high energy density plasma / Soft X-ray source / Intense X-ray source / Z pinch discharge / Plasma focus / High current discharge |
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| Research Abstract |
In this study, the ultra high energy density plasma is produced by the plasma focus discharge using a capacitor bank of 1.6 * 30 muF (150 kJ) with which discharge current more than 1 MA is possible. Relationship between plasma evolution and soft X-ray emission is obtained with developing several diagnostic systems.
Main results are following :
(1) In the plasma focus devices, a satisfactory pinch easily occurs when pure hydrogen is employed. We accomplished the pinch with high Z gas by decoupling the initial stage of the discharge and the pinch stage, stating the discharge in pure hydrogen then puffing the high Z gas just before the pinch stage.
(2) We developed an imaging Bragg spectrograph with which a monochromatic soft X-ray image is obtained specifying its wavelength. Record of the image is usually carried out using such as Kodak direct exposure film whose handling is rather troublesome. We devised a method to obtain the linear relationship between the soft X-ray intensity and the blackness of the image of commonly used photographic film such as Kodak TRI-X.
(3) A pinhole camera which enables a quantitative measurement of the soft X-ray intensity in 2-dimension with a narrow pass band was developed. This makes possible to obtain the plasma parameters such as the electron temperature and the electron density of the high energy density plasma.
(4) In the plasma focus device with the gas puff system, it was observed that the electron-density and temperature are in the order of 10^<20>/cm^3 and keV,respectively. The soft X-ray source mainly consists of the hydrogen-like and the helium-like ions. When argon is used as a puffed gas, 10^<21> photons in K-lines were observed per discharge in the direction of the electrode axis.
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