Lasetron: a proposed source of powerful nuclear-time-scale electromagnetic bursts.

Electromagnetic bursts of substantial energy on a nuclear time scale of 10(-21)-10(-22) s [zeptosecond (zs) to sub-zs] can theoretically be generated by a perawatt or multiterawatt laser beam focused on a subwavelength-size solid particle or thin wire. Terawatt laser in a similar setup could be instrumental in reaching the subattosecond domain. The system may also generate a half-cycle pulse magnetic field on astrophysical scale up to approximately 10(6) T.