Review of Triboluminescence Impact Research at Projectile Speeds of 1 m/s to 6 km/s

Abstract

Over the last decade, research has been conducted to investigate the use of triboluminescence (TL) as the active element for impact sensors. TL is defined as the emission of light produced by mechanical action. For the last decade, the authors has obtained extensive experience in characterizing TL and has successfully measured it during impacts with speeds of 1 m/s to about 5.6km/s. For the most part, zinc sulfide and europium dibenzoylmethide triethylammonium (europium tetrakis) compounds have been used as sample materials, since both emit strong TL. Recent ballistic results also show there is a ~1nm shift in the triboluminescent peak wavelength between the high speed 30 caliber and low speed 9mm projectiles augmented with ZnS:Mn powder. In fact, the 9mm peak wavelength for triboluminescence is similar to what was found in earlier measurements. More significantly, collected results also show that the triboluminescent emission yield for ZnS:Mn appeared to be a function of speed for collisions up to 6km/s using a two-stage light gas gun. These research programs expanded the knowledge base for using TL as the active element for sensors to detect high-speed impacts.