Bromine-isotope selective ionization using field-free alignment of IBr isotopologues with a switched nanosecond laser pulse

Akagi, Hiroshi*; Kumada, Takayuki   ; Otobe, Tomohito*; Itakura, Ryuji*; Hasegawa, Hirokazu*; Oshima, Yasuhiro*

We demonstrate isotope selective ionization of IBr and IBr isotopologues using field-free alignment induced by a linearly-polarized nanosecond laser pulse with rapid turn off at the maximum. Following the switched nanosecond pulse irradiation, a 60-fs laser pulse ionizes one of the isotopologues preferentially. The ion yield ratio (IBr)/(IBr) varies in the range of 0.93-1.06, depending on time delay between the pulses. This is the first demonstration of laser isotope separation of heavy elements using field-free alignment and angular dependent ionization.