| abstract |
The invention is characterized in that the a explosive part ( 1 ) comprises two initiation devices ( 7 ) arranged on each end face ( 5 ) with connections to an inner explosive charge ( 2 ), the two initiation devices ( 7 ) being arranged for optional initiation of the inner explosive charge ( 2 ), with or without an ignition delay. At, and in that the diameter di of the inner explosive charge ( 2 ), the thicknesses ti, ty of the two insulating layers ( 8, 9 ) and thickness is of air gap ( 10 ) are chosen such that energy from two colliding detonation fronts along the common centre axis A-A is required in order for the initiation to lead to detonation of the outer explosive charge ( 3 ). The invention also relates to a method for the above. |