THEORETICAL-ANALYSIS OF A PULSED-LASER-DRIVEN HYPERVELOCITY FLYER LAUNCHER

High-power but low-total-energy pulsed lasers can be used to accelerate small-diameter, thin flyers to velocities in excess of several kilometers per second. The geometry under consideration involves placing the flyer on the end of an optical fiber through which the laser pulse is delivered. The blowoff products driving the flyer are thus fully tamped. A model, based on the Gurney theory for explosively driven plates, is derived for predicting the final velocity of these flyers. All but two of the required input parameters are readily available; those two can be extracted from one limited set of experimental measurements. Data on aluminum flyers illustrate that once the input parameters have been determined, the model predicts changes resulting from variations of laser fluence and pulse duration as well as flyer thickness and diameter. Additional data on copper and magnesium indicate that the energy-coupling efficiency can vary by at least 50%, depending on the flyer material.