1993 Fiscal Year Final Research Report Summary
Development of Apparatus for Solids under Ultra-High Pressure Shock Compression
| Project/Area Number |
04650590
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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 |
資源開発工学
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| Research Institution | Kumamoto University |
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Principal Investigator |
HIROE Tetsuyuki Kumamoto Univ., Faculty of Eng., Assoc.Prof., 工学部, 助教授 (90218826)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIWARA Kazuhito Kumamoto Univ., Grad.School, Res.Assistant, 大学院・自然科学研究科, 助手 (50219060)
MATSUO Hideo Kumamoto Univ., Faculty of Eng., Professor, 工学部, 教授 (00040395)
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| Project Period (FY) |
1992 – 1993
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| Keywords | imploding Shocks in Solids / Ultimate State / Random Choice Method / Wire Explosion / Shadowgragh |
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| Research Abstract |
Plane detonation waves with the area of 100mmf and the flatness of (〕SY.+-.〔)100ns were produced by exploding 16 parallel copper wire-rows covered over the surface of explosive PETN(density : 0.6 g/cc) instantaneously, using a high voltage impulsive current from the capacitor bank of 12.5mF, max.40kV.The developed wave generator was successfully applied to shock synthesis and recovery of diamond.
Next, such wire-explosion technique was applied to produce one-dimensional cylindrical imploding shock waves in solids. As the first step, the wire-row conditions were obtained to generate the imploding detonation waves within the longitudinal arrival-time jitter of (〕SY.+-.〔)170ns in long cylindrical PETN shells(outer dia : 100mm, length : 132mm). Then transparent PMMA cylinders(dia : 42-52mm)were set inside the cylindrical charge assemblies(PETN,PETN/SR), and the shadowgraphs of imploding shocks in PMMA were taken, using high-speed framing or streak camera. The photos showed that the axisymmetry of the imploding shocks was maintaied in the focusing stage and the shocks accelerated near the focusing point. As the result, testing apparatus for materials under ultimate state of ultra-high pressure shock compression was developed.
One-dimensional random choice code has been developed for the medium of layred structure including solids and gases, and applied to the numerical simulation of the explosive-driven cylindrical imploding shocks in solids. The total energy contained in the center region of solid cylinder was compared with the chemical energy of the explosive. The code successfully reproduced the experimentally observed shock trajectories in use of PETN only. The numerical results also showed that a negative pressure caused by the interferance of the strong expansion waves emerged in the period after the shock was reflected on the axis and it is not easy to recover the condensed matter at the center.
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Research Products
(12 results)
