Anomalously fast relaxation of metastable states of Ca+ Eu, and Eu+ and impact emission from Ca+, Eu+, and Sr+ ions

An anomalously fast relaxation of metastable states of the Eu atom and of the Ca(+) and Eu(+) ions was observed in collisions with He and Ne atoms. The anomalously fast relaxation of metastable states of Ba(+), Ca(+), Eu(+), and Sr(+) has also been observed in quasi-resonant charge exchange with these atoms. These results indicate that the fast relaxation of the metastable states of metal atoms and ions at energy defects significantly above the thermal energy is not unique to the 7D0 state of the europium ion. The possibility of using this phenomenon in the development of high-power collisional metal-vapor lasers is noted.