Magnetic fields in excess of ${10}^7$ G are expected to arise in laser-produced plasmas in which a discontinuity in atomic weight of the target occurs in the focal spot. The upper limit to $B$ is controlled by fluid disassembly of the field layer due to magnetic pressure. This may provide a means for direct measurement of these fields in laser-produced plasmas.

• Received 18 March 1974

DOI:https://doi.org/10.1103/PhysRevLett.32.1179