SLAC high power hydrogen target

We describe a hydrogen target designed for use with the SLAC high power electron and photon beams. The target makes use of rapid convection currents caused by the heating of the hydrogen by the beam and the immediate cooling of the warmed hydrogen by a heat exchanger positioned a few centimeter above the beam. Provided that the size of the beam spot is not too small, the convection currents set up, cause the hydrogen to move sufficiently rapidly to prevent the hydrogen (held several degrees below its boiling point by the heat exchanger) from boiling.