Detonation velocity measurements using rare-earth doped fibres

Abstract

In this paper, a simple detonation velocity measurement scheme is presented, which exploits the length-dependent amplified spontaneous emission (ASE) power emitted by off-the-shelf Er-doped fibres. This measurement scheme is first calibrated using cutback tests, so that minimal processing is required between data collection and velocity readout. We then demonstrate the use of this method in an explosive cylinder test and achieve a spatial resolution of approximately ±2 mm, owing to its implementation in a helical geometry. Alongside the standard Er fibres, a specially made, high-concentration Er/Yb-doped fibre is also calibrated, which demonstrates a potential spatial resolution approaching ±20 µm.