  The quantification of isotopes content in materials is extremely important in
many research and industrial fields. Accurate determination of boron
concentration is very critical in semiconductor, superconductor and steel
industry, in environmental and medical applications as well as in nuclear and
astrophysics research. The detection of B isotopes and of their ratio in
synthetic and natural materials may be accomplished by gamma spectroscopy using
the $^{10}$B(p,$\alpha_1 \gamma$)$^7$Be and $^{11}$B(p,$\gamma$)$^{12}$C
reactions at low proton energy. Here, the $^{10}$B(p,$\alpha_1 \gamma$)$^7$Be
cross section is reported in the center of mass energy range 0.35 to 1.8 MeV.
The $E_\gamma$= 429 keV $\gamma$ rays were detected at 45$^\circ$ and
90$^\circ$ using a NaI(Tl) and an HPGe detectors, respectively. In the
presented energy range, previous cross sections data revealed discrepancies and
normalisation issues. Existing data are compared to the new absolute
measurement and discussed. The present data have been subtracted from a
previous measurement of the total cross section to derive the contribution of
the $\alpha_0$ channel.
