Direct capture cross section of ${}^9\mathrm{Be}(n,\gamma ){}^{10}\mathrm{Be}$

The cross section of the ${}^9\mathrm{Be}(n,\gamma ){}^{10}\mathrm{Be}$ reaction was calculated in the direct capture model. All parameters of the calculations were adjusted to properties of the ${}^9\mathrm{Be}+n$ system at thermal energies. The calculated cross section at thermonuclear energies shows the expected $1/v$ behavior of $s$-wave capture at low energies, but increases towards higher energies as typical $p$-wave capture. Excellent agreement between new experimental data in the astrophysically relevant energy region and the present calculation is found.

Figure 1

Cross section of the ${}^9\mathrm{Be}(n,\gamma ){}^{10}\mathrm{Be}$ reaction. The calculated total cross section (full black line) is composed of $s$-wave (light blue dotted) and $p$-wave (orange dashed) DC plus resonances (green dash-dotted). Excellent agreement with the experimental data [1, 6] is found. For further discussion see text.

Figure 2

Wave functions $u^2\left(r\right)$ [upper part (a), logarithmic scale) and $u\left(r\right)$ [middle part (b), linear scale] of the $0^{+}$ ground state and the $2^{+}$ and $1^{-}$ doublet of states at $E_x=5.96$ MeV (see also Table 1). The resulting integrand of the overlap integral in Eq. (1) is also shown for $E=100$ keV [lower part (c)]. For further discussion see text.

Figure 3

Astrophysical reaction rate $N_A〈\sigma v〉$ for the production of ${}^{10}\mathrm{Be}$ in the ${}^9\mathrm{Be}(n,\gamma ){}^{10}\mathrm{Be}$ reaction.