Development of a low-debris laser driven tape drive soft x-ray source

This paper focuses on debris mitigation in a laser driven tape drive x-ray source. A smart design is being used to minimise the effect of shockwave reflection from the target's back and a continuous rough pumping is utilised to obtain an efficient purging of big lumpy debris particles out of the interaction chamber. The effect of low pressure (3-6 mbar) nitrogen buffer gas is studied together with a moderate magnetic field (0.14 Tesla) on both debris spall and hot ions trajectory. The target material for this work is a 15 mu m VHS video tape composed of Mylar as carrier film with Fe2O3 and CrO2 powder. The experiments were conducted using a long pulsed 800ps, 50 Hz Nd: YAG laser. The results obtained appeared to be promising in reducing the damaging effect of large debris particles (between 50 and 140 microns) as well as small particles (similar to 5 microns) that deteriorates the efficiency of delicate optics.