New cross-beam technique for charge transfer cross section measurement using a pulsed ion beam produced by laser photoionization

Abstract

A new cross-beam technique has been developed to measure the charge transfer cross sections of metallic atoms which have not been experimentally investigated previously. Two high-density atomic beams were produced by the vaporization of a metal heated with an electron beam gun. A pulsed ion beam produced from one atomic beam by laser photoionization was collided with another atomic beam. By colliding the pulsed ion beam produced in this manner with the second atomic beam, the apparatus was simplified in comparison with conventional one; additionally, only a single pulsed laser shot is required to obtain the data necessary to determine a cross section. By using repetitive laser pulses it is possible to acquire in a short time a more accurate cross section as a function of impact energy. The apparatus was successfully applied to the measurement of the charge transfer cross section of gadolinium, a metallic atom with a relatively high ionization potential and high melting point.