LIF Velocity Measurement of Sputtered Boron Atoms from Boron Nitride Target

Details of the boron nitride (BN) sputtering process are of interest for diagnostics and modeling of Hall thruster erosion. This contribution presents velocity distributions of sputtered boron atoms from BN targets. Measurements were performed for normally incident argon ions at energies of 300, 800, and 1200 eV, and xenon ion at 1200 eV. The velocity distributions were found using laser induced fluorescence (LIF) spectroscopy of boron with a tunable diode laser system in the vicinity of 250 nm. The LIF velocity profiles for sputtered boron from BN were fitted with Thompson distributions giving surface binding energy of Eb=4.8±0.2 eV. Measurements were validated with a pure boron target giving a binding energy of Eb=5.7±0.3 eV in agreement with published values.