Measurement of a large B(E2) in 10B

It has been known for some time that the E2 transition strength from the 4.77-MeV, 3+ level in 10B to the 0.72-MeV, 1+ level was measured to be much larger than one would expect in light nuclei. Kurath has shown that a large enhancement may be expected due to collective effects. However, the experimental value was still nearly three times larger than could be easily accommodated. Using the Physics Division Dynamitron, the authors remeasured this quantity using radiative capture of alpha particles on an evaporation-in-situ 6Li target. Photons of 720 keV were detected using a Ge(Li) spectrometer. The detection efficiency was determined using the well-studied radiative-capture process to the 5.16-MeV state in 10B. The authors find that for the 4.77 → 0.72-MeV transition, B(E2) = 21 +/- 2 e2fm4 whereas Kurath predicts approximately 13e2fm4