Measurement of the 2200 m/sec neutron-proton capture cross section

Abstract

The neutron-proton capture cross section at the neutron laboratory velocity of 2200 m/sec has been determined from the time decay of the thermalized neutron population following short bursts of fast neutrons in water samples of widely varying sizes. Use of an intense pulsed neutron beam enables elimination of many of the problems encountered in earlier experiments. The present result for this cross section is 332.6\ifmmode\pm\else\textpm\fi{}0.7 mb, which is the most precise of any result obtained by this method and is comparable in accuracy and consistent with the most accurate values determined by any method.NUCLEAR REACTIONS $p(n, \ensuremath{\gamma})d$, $E=0.0253$ eV; measured lifetimes of thermal neutrons in water samples of various sizes; deduced ${\ensuremath{\sigma}}_{a}$.