Invisible infrared light from Trident Laser, enters from the bottom to interact with a one-micrometer thick foil target in the center of the photo. Credit Los Alamos National Laboratory
The laser pulse produces the plasma, an ionized gas, but only for a trillionth of a second.
During this time some electrons from the foil are accelerated to virtually the speed of light, and some ions are accelerated to energies of tens of millions of volts. In this time-integrated image, one sees many colorful plasmas that result from the collisions of energetic X-rays and particles with nearby surfaces. Various diagnostic devices located around the edge of the image are illuminated by the plasmas. The green light is caused by the second harmonic of the laser, and is produced by a nonlinear process taking place at the laser-plasma interface (see Chapter Four). Bits of debris from the target are seen as orange streaks of light, some of which ricochet from the surrounding environment, and some of which produce a colorful dance of twisted braids as they spin in flight.