The [Formula Presented] reaction below 100 keV

The [Formula Presented] reaction was studied by measuring the [Formula Presented] rays that were produced when 80–100-keV polarized protons were stopped in a thick [Formula Presented] target. Cross sections and vector analyzing powers at [Formula Presented] were determined as a function of energy for capture to the ground and first excited states of [Formula Presented] These analyzing powers are particularly sensitive to the interference between s- and p-wave contributions, and to the relative phase between direct and resonance amplitudes. The results were used to produce a reliable extrapolation of the astrophysical S factor at 0 keV by means of a direct-capture-plus-resonances model calculation. The value of [Formula Presented] that was obtained for [Formula Presented] is in agreement with previously determined values, but for [Formula Presented] the value of [Formula Presented] is [Formula Presented] and is more than twice as large as previously determined values. © 2000 The American Physical Society.

Duke Scholars

Author John H Kelley Physics