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volved in the calculation reveals that while they are large, they could not, without the greatest difficulty, be stretched to explain so large a discrepancy. 98, A similar calculation on the data from references 3 and 4 indicates that, if a dineutron were stable, 10 for bismuth, a(8,y)<10r™ cm 2 ; for helium, a(8,y) <5X 10~2 8 cm 2 .9a Note added in proof:-It has recently been found pB. L. Cohen and T. H. Handley, "Experimental Studies of (p,l) Reactions," Phys. Rev. (to be published)]] that the statistical theory successfully predicts the cross sections for (p,t) reactions occurring by compound nucleus interaction in iron and palladium. Since the uncertainties in these calculations are very similar to those in the dineutron calculation (the thresholds are about the same), the dineutron calculation is probably not in error by as much as a factor of ten. 10 The statistical theory does not predict (5,7) cross sections, so the results of the calculation are given in terms of

A fast-coincidence scintillation spectrometer has been developed for thermal-neutron capture-gamma studies at the Livermore 1-Mw pool-type reactor. The added-neutron binding energy in V 51 was measured as 11.1 ±0.1 Mev. Cascade radiations for V 51 * were observed and a decay scheme is established which verifies a previously proposed (p,p') level scheme. Spin assignments for most of the V 51 (p,p f ) reported levels below 4.0 Mev are proposed and the level order for the (I/7/2) 3 proton configuration levels is established as 7/2" (ground state), 5/2", 3/2~, 11/2", 9/2",' and 15/2~ spin with excitation energies of 0.32, 0.93, 1.61, 1.81, and 2.70 Mev, respectively. Of the various nuclear force assumptions that can be made, the short-range force approximation (5-type interaction) and weak surface-coupling effects for V 51 * configuration states appear to give the best match between theory and experiment. A previous calculation using experimentally measured splittings of the j 2 configuration together with tabulated coefficients of fractional parentage gives excellent agreement with experiment. Evidence is also found for (l/V/2 2 )o2^3/2and (l/ 7 /2 2 )ol/5/2-proton single-particle levels at 2.41 and 2.55 Mev, respectively, as well as for additional low-spin states between 2.70 and 3.38 Mev which possibly represent even states resulting from excitation of a lower shell proton to give a (l/V/2 4 )o configuration plus a proton hole in the vacated shell. Experimental results suggest that the V 51 * 20-28 core is a more rigid structure than the Ca 43