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The absorption of stopped n in 181Ta and 2~ has been investigated by studying prompt and delayed 7-ray spectra. Absolute cross-sections for the yield of isotopes per captured n-in (n-, xn) reactions, as well as the relative probability of populating nuclear states of different spins have been measured for the hafnium and lead isotopes, respectively. A spin as high as 20 has been observed in the production of 2~ The ground-state rotational bands of the hafnium isotopes are excited to spin values up to 16. Neutron multiplicities as large as 15 have been observed for both targets. A neutron multiplicity of -8 is most probable for both tantalum and bismuth targets. The strong interaction monopole energy shift e o and width F o for the 4f level are found to be e0(~81Ta)=540+100 eV; ~o(2~ 1790_+150 eV; Fo(181Ta)=225 +57 eV; F0(2~ = 1166 _+ 70 eV. The quadrupole moments, determined from the hyperfine splitting of the 4f pionic atom level, are Q=3.30+0.06b and Q=-0.50+0.08b for 181Ta and 2~ respectively.

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