Observation of excited H/sup 0/ atoms produced by relativistic H/sup /minus// ions in carbon and formvar foils

Abstract

We have measured the relative yield of several low-lying excited states of neutral hydrogen atoms produced by the passage of 226-MeV and 581-MeV H/sup /minus// ions through thin carbon foils and a tilted formvar foil. The relative yields of H/sup /minus///sub /asterisk//(n = 2,3, 4) were measured for 17 different carbon foils ranging in thickness from 662 /angstrom/ to 5386 /angstrom/ at 581 MeV. The relative yield of H/sup 0//sup /asterisk//(n = 2) was also measured for these carbon foils at 226 MeV. These data exhibit a significant deviation from a simple yield curve indicating that a more complex mechanism than has previously been thought is responsible for producing the excited states. The relative yields of H/sup 0//sup /asterisk//(n = 2,3) were measured for a tilting formvar foil at 226 MeV; unexplained dips appear at incidence angles of /theta/ /approx/ 12/degree/ and /theta/ /approx/ 15/degree/ in the yield of n=2 and n=3 states, respectively. 19 refs., 7 figs., 1 tab