Time‐Resolved Spectroscopy of Ultraspeed Pellet Luminosity

Improved optical instrumentation has resulted in high time‐resolution spectrograms of the luminosity associated with ultraspeed aluminum pellets. These data indicate that in many cases the light is emitted in two phases: (1) the ballistic, or air shock, characterized by atomic metal lines and a strong continuum; (2) AlO bands that appear about 150 μsec after the metal is ablated from the pellet.