Source of metastable H(2s) atoms using the Stark chirped rapid-adiabatic-passage technique

We propose the use of Stark chirped rapid-adiabatic-passage method, a technique in which the energy of a target state is swept through resonance by a slowly varying dynamic Stark shift to induce complete population transfer from the ground $1s$ state to the metastable $2s$ state of the hydrogen atom. Parasitic ionization processes are strongly reduced by using a two-color excitation scheme. Our detailed numerical calculations show that under judicious choice of pulse parameters, up to 98% of the population can be found in the $2s$ state at the end of the process.