Abstract
The possible role of the reaction H-+H+ to or from H+H* in populating the n=3 level of the hydrogen atoms in the afterglow plasma of a 2 m Z-pinch in hydrogen is investigated. The method used is to observe the effect of any H- destruction on the Halpha emission from the plasma in the region of the discharge axis, due to irradiation of the plasma by a 50 MW Q-switched ruby laser beam passing along the axis. It is estimated that not more than 35% of the n=3 level population arises from this reaction.