Intensity and time profile of recombination luminescence produced by an α-particleα-particle in dense xenon gas

The time profile of recombination luminescence of dense xenon gas irradiated by an α-particleα-particle was absolutely measured in the density range of 0.027–0.112g/cm3 with the aim to investigate the intensities of recombination luminescence at zero electric field. It was found that the number of scintillation photons due to the recombination luminescence increases with xenon density up to around 0.05g/cm3, and then becomes nearly constant (=2.32×105=2.32×105 photons for an α-particleα-particle with 5.49 MeV). The probability of recombination between electrons and ions at zero electric field is about 88% in the density range of 0.05–0.112g/cm3. It was also found that the percentage of slow component (∼∼ sub-milliseconds) in the recombination luminescence decreases with density from 73% to 33% in the density range from 0.027 to 0.112g/cm3.