Detection of recurrent fluorescence from anthracene using an electrostatic ion beam trap

Abstract

The recurrent fluorescence of anthracene cations (C₁₄H₁₀⁺) was investigated using an electrostatic ion beam trap. The photon emission from the excited anthracene cations confined in the trap was observed in the order of milliseconds. The photon yields as a function of the wavelength in the range of 450–860 nm were measured by optical filters and a cooled photomultiplier, which revealed that the observed photon emission is attributed to the D₂ → D₀ transition of C₁₄H₁₀⁺. However, the time range of the photon emission is considerably longer than that of the spontaneous emission induced by the D₂ → D₀ transition (<1 μs). The number of photons emitted by the recurrent fluorescence of C₁₄H₁₀⁺ as a function of time was calculated using the previously reported theoretical decay rates of C₁₄H₁₀⁺ by recurrent fluorescence and thermal dissociation. The calculation results justified the time dependence of the measured number of photons over the extended time range. These results demonstrate that we successfully detected recurrent fluorescence photons emitted from excited anthracene cations.