Cross sections for single-and double-electron capture have been measured for incident ions of C, N, and 0 with initial charges + 3 to + 6 colliding with molecular hydrogen at velocities between 0.3 X 10 and 1.2 X 10 cm/sec. The single-electron-capture cross sections for a particular incident charge are nearly constant with changing velocity. The single-capture cross sections range from about 7 X 10 ' cm' for + 3 incident ions to 40X 10 ' cm for +6 incident ions. Double-electron-capture cross sections are roughly one order of magnitude smaller. The data are qualitatively interpreted on the basis of the molecular potential-curve model for slow collisions.

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Two new isotopes of californium have been identified through bombardments of U, U, and 3U with C ions from the Oak Ridge isochronous cyclotron. They decay with half-lives of 3.78 +0.70 and 1.06 +0.15 min and with the emission of e particles of 7.335 +0.005 and 7.590 +0.010 MeV, respectively. Analysis of the excitation functions for these e emitters favors the assignment of mass 241 to the former and mass 240 to the latter; also, the 7.335-MeV activity was shown to be chemically similar to californium. New values for the~-particle energies of 4 Cf were obtained: 7.385 +0.004 and 7.351 +0.006 MeV, assigned, respectively, to e-decay transitions to the ground and first excited states of 8Cm.

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