$^{\mathrm{10,11}}$B($\alpha $,$n )^{\mathrm{13,14}}$N cross section measurements$^1$

$^{\mathrm{10,11}}$B($\alpha $,$n )^{\mathrm{13,14}}$N have been identified as possible background sources for underground experiments at low $E_{\alpha}$ energy [1]. These reactions have been studied at University of Notre Dame's Nuclear Science Laboratory using Santa Anna 5 MV accelerator. $^{\mathrm{11}}$B($\alpha $,$n )^{\mathrm{14}}$N was measured with a $^{3}$He counter, and a good R-matrix fit was obtained, which shows our data in agreement with other published data. Measurement of $^{\mathrm{10}}$B($\alpha $,$n )^{\mathrm{13}}$N was performed down to $E_{\alpha}=0.57$MeV, with two deuterated liquid scintillators, EJ315 and EJ301D, and with the help of unfolding technique, neutron energy information can be extracted. EJ301D is a newly-developed neutron detector, with better pulse shape discrimination [2], and has been used to do angular distribution measurements. Additionally, the ($\alpha ,\alpha_1 \gamma$) and ($n,p\gamma$) channels have been monitored independently by observation of 718keV $\gamma$ transition in $^{10}$B and 3853keV $\gamma$ transition in $^{13}$C. Preliminary analysis indicates the discovery of a new resonance in low energy region. [1] D.-M.Mei \textit{et al.} NIMA \textbf{606}, 651(2009). [2] F.D Becchetti \textit{et al.} NIMA \textbf{820}, 112(2016).