COLLISIONAL EXCITATION AND DESTRUCTION OF METASTABLE STATES IN A STORED ION-BEAM

A laser probing technique has been applied to a stored ion beam of Xe to study collisional destruction of metastable states as well as coll isional excitation by the residual gas in the storage ring. The result s are of great importance for the evaluation of lifetime measurements of metastable states in storage rings. For the states studied in Xe+, it was found that neither of the two processes caused systematic error s in the lifetime determination. It is also shown that the method can yield partial cross sections for collisional excitation.