Charge Transfer between Ground-State Si~3+ and He at Electron-Volt Energies

摘要

The charge-transfer rate coefficient for the reaction Si~3+(3s~ 2S) + He →products is measured by means of a combined technique of laser ablation and ion storage. A cylindrical radio-frequency ion trap was used to store Si3+ ions produced by laser ablation of solid silicon targets. The rate coefficient of the reaction was derived from the decay rate of the ion signal. The measured rate coefficient is 6.27_(-0.52_~(+0.68) * 10~-10 cm~3 s~-1 at T_equiv = 3.9 * 10~3 K. This value is about 30/100 higher than the Landau-Zener calculation of Butler & Dalgarno and is larger by about a factor of 3 than the recent full quantal calculation of Honvault et al.