Visualization of explosion phenomena is very important and essential to evaluate performance of explosive effects. Explosion phenomena generate blast waves and fragments from cases. We must protect our visualizing equipment from the impulsion. When the flash X-ray system is used at an explosion site, the tube heads, from which X-ray is irradiated, are surrounded with steel plates to protect from blast waves and fragments. The high-speed video camera HPV-1 has been applied to visualize many types of explosion effects at many universities and laboratories. The control unit of the video camera is separated from the camera head with cables, but the lens is coupled with the camera head. We had an idea of trying to separate the lens from the camera head, actualizing shootings with the video camera under the severe blast environment. We employed a fiber-optic cable of 1.8 m length to separate the front lens from the camera unit. Two lenses inserted a tandem ring were set to connect the cable with the camera unit. We obtained some clear images from this newly comprised camera system at normal temperature and pressures, using a dichroic halogen lamp as the light source. Furthermore, we tried shootings under emission by detonation at an explosion site. We could also obtain clear images using appropriate additional light sources. We decide that this system is very useful for shootings at a dangerous place, e.g. explosion site and from the direction of unachievable under normal circumstances.
爆発現象の可視化は爆風や破片から撮影機材を防御する必要があることから，特殊防護仕様のX線照射部を持つフラッシュX線撮影システムが主として使用されてきた。しかし，撮影できる画像は数枚で現象の連続的な解析は不可能であった。高速度ビデオカメラによる連続撮影を実現するためには，対物レンズとカメラ本体を光ファイバーケーブルで分離し，レンズ部分だけを爆発現象近くに置くことが必要となる。室内での試写と爆発ピットでのLSCジェット生成状況の撮影で，レンズ分離方式による爆発現象の高速度撮影が可能であることが確認できた。撮影したLSCジェットの速度は従来の理論で算出した値と合致していた。
High-speed video camera, Fiber-optic cable, Moving image, LSC jet formation.