The authors have developed a cylindrical imploding shock generator, which produces auper high
pressure of Tera Pascal region in solids by focusing one - dimensional cylindrical shocks on the basis of
preliminary experimental results. In this study, surface initiation of the PBX(plastic bnded explosive)
explosive shell begins at the collision of a cylindrical thin flyer driven by the detonation of low - density
PETN(pentaerythritol tetranitrate) shell, which is initiated by the explosion of a etched cpper mesh
using a high voltage impulsive current. Observed imploding shocks are focuusing in PMMA cylinders
inside the PBX shell with a fairly good axisymmetry. The comparison with numerical simulation has
suggested that the C - J pressure is almost achieved in the PBX in this study.
The authors have constructed a recovery system for extremely high pressure compaction of material
applying the imploding shock generator. In this system, the explosion of liquid explosive NM
(nitromethane) is newly installed outside the sample material to weaken the influence of the explosion waves,
which is called AMT(active momentum trap). In the experiment using the AMT system,
the model blocks have been recovered successfully. The experimental results and the additional
numerical study suggest that the developed AMT is effective for recovery and this total system has a
possibility to compress materials up to Tera Pascal region without fracture.
筆者らは予備実験結果を基に, 一次元円筒状収束爆轟波によって固体中にテラパスカル域の超高圧を発生させる円筒状収束波発生装置の開発を行った｡ 強い収束衝撃波発発生のために主爆薬に高性能爆薬PBX(plastic bonded explosive)を使い, これを周囲から一斉起爆するために銅細線列の線爆発によるPETN(pentAerythritol tetranitrate)の面爆轟波発生装置を用いている｡ 円筒状収束衝撃波発生実験の結果, 精度の良い収束衝撃波の発生に成功し, 数値シミュレーションと比較して理論検討も行った｡ また, この円筒状収束波発生装置の中心軸に設置した試料の周りに液体爆薬層を設け, その爆発によって収束衝撃波後方からの膨張波を遮断する回収システム(active momentum trap ; AMT)を新たに考案し, 極限的な材料圧縮を可能とする装置の開発を行い試料の回収に成功した｡ これらの結果から, 本研究で開発した極限圧縮装置は従来の爆縮装置では到達できなかった超高圧領域における材料の圧縮と回収を可能とし, 今後高圧物性研究や材料合成などへ有効に応用できるものと考えられる。