Terry Kammash - NASA's Institute for Advanced Concepts

Target Surface GeometryUse a material which will “trap” the laser light, toenhance the generation of hot electrons.Electron Microscopyof LaserBlackMurnane et al. APL 62 (1993) used gratings and clusters,Kulcsar et al. PRL 84 (2000) used metallic “velvet”.Both showed enhanced X-ray yield from enhance electronheating from efficient coupling.100 µm2 µmLaser Spot Size ~ 6 micronsLaserBlack ® is > 96% absorptive at 1 mm.Results:•30 mm Laserblack target ~8.2 MeV•Enhancement in the numberof maximum energy protons•Beam profile does not suffer,regardless of which surfacehas been coated, i.e. noimprinting even from rear-side>1.3MeV31º div.