High Isp Propulsion through Electromagnetically-Confined Laser Ablation

To meet future military space needs, the Air Force has identified the need for ultra-high specific impulse thrust devices. These devices need to be capable of providing high current atomic or molecular beams with velocities on the order on 10^6 meters persecond, or approaching relativistic speeds. Laser ablation has long been recognized as a method of obtaining very high temperature plasmas. This is particularly true with sub-picosecond lasers, which can reach intensities in excess of 10^17 W/cm2,generating fully-ionized plasmas. We intend to exploit the high energies and ionizations to the fullest extent possible, through substantial electromagnetic confinement and control. We will also apply a variety of unique diagnostic techniques to explorefurther applications and capabilities of these extremely high energy-density regimes. In addition to extremely high Isp thrusters, confining and directing the highly ionized laser-ablation products also has a large number of terrestrial applications.Some applications are relatively exotic, such as tabletop particle accelerators, however, others have much more daily application, such as a variety of materials processing techniques.