Description
Accurate atomic data for boron II ($\text{B}^{+}$) is essential for plasma modelling. In particular, there is currently a strong focus on using plasma modelling to interpret recent experiments on solid boron injection (SBI), a promising real-time alternative to conventional glow-discharge boronisation (GDB). In this work, we present a converged dataset of electron-impact excitation and ionisation cross sections for $\text{B}^{+}$, calculated using the convergent close-coupling (CCC) method. Our calculations were performed for scattering from the $2s^2~{}^{1}\text{S}$ ground state, over incident energies ranging from threshold to $500~\text{eV}$. Ionisation cross sections from the $2s2p~{}^{3}\text{P}^{\circ}$ metastable state were also calculated to allow for direct comparison with crossed-beam experiments. To facilitate direct application in collisional-radiative models, Maxwell-averaged effective collision strengths have been calculated from the present excitation cross sections over the temperature range of $10^3$ to $10^6~\text{K}$.
Compared with existing excitation calculations that utilised the $R$-matrix with pseudostates (RMPS) method, we achieve an improved target-structure model that is more closely aligned with the recommended NIST energies and optical oscillator strengths. Consequently, mixed agreement is observed with the previously calculated effective collision strengths.
For ionisation cross sections, excellent agreement is demonstrated with previous RMPS calculations and recent crossed-beam measurements. Moreover, we show that earlier measurements exceed the theoretical ceiling of a pure metastable beam. We conclude that the discrepancy with current results cannot be attributed solely to an underestimation of the metastable fraction, as previously suggested.
In this work, we establish a new benchmark dataset for $\text{e-}\text{B}^{+}$ scattering to enable high-precision plasma modelling.
| I am the presenting author | Yes |
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