Neutron Resonances In The Kev Region - Heavier Odd Elements

The neutron total cross sections have been measured as functions of energy for thallium (0.1-80), yttrium (6-80), rubidium (5-25), copper (1-80), and chlorine (6-200); peaks are observed which appear to be due to single resonances. The energy range of the measurements in kev is indicated in parentheses. Lanthanum (1-10) and yttrium (0.5-10) show peaks which may be due to single resonances. Lanthanum (10-100), praseodymium (0.5-150), gallium (1-60), gold (1-40), tantalum (1-6), silver (2.5-11), niobium (0.5-10.5), cesium (1-4.5), and iodine (1-15) show flat or wavy cross-section curves which are typical of spectra so poorly resolved that no single resonances are observed. Our failure to observe even the strongest single resonance in any of these elements is consistent with a roughly exponential distribution of reduced widths. Useful averaged cross sections are tabulated for some of the latter elements.