Cross section of the capture reactionHe3(α, γ)Be7

The cross sections for the astrophysically significant reactions ${}_{}{}^3{}_{}{}^{}\mathrm{He}(\alpha , \gamma ){}_{}{}^7{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}({}_{}{}^3{}_{}{}^{}\mathrm{He}, \gamma ){}_{}{}^7{}_{}{}^{}\mathrm{Be}$ have been measured near 900 keV in the center of mass by measuring the activity of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ produced in a gas cell. The results imply a zero-energy cross-section factor $S\left(0\right)\mathrm{}$ of 0.63(4) keV b, consistent with the larger of previous measurements. Extant values of $S\left(0\right)\mathrm{}$ are reviewed and a recommended value for use in stellar evolution calculations is presented.