Detection of Recurrent Fluorescence Photons.

Area of Science:

• Physical Chemistry
• Astrochemistry
• Spectroscopy

Background:

• Understanding molecular processes in isolated environments, such as interstellar space, is crucial for astrochemistry.
• Distinguishing between different fluorescence pathways is essential for accurate interpretation of spectroscopic data.
• The role of excited electronic states in molecular cooling and stabilization requires further investigation.

Purpose of the Study:

• To detect and characterize recurrent fluorescence (RF) from the C_{6}^{-} molecular ion.
• To provide clear evidence differentiating RF from normal fluorescence.
• To explore the implications of RF for molecular cooling and stabilization in interstellar environments.

Main Methods:

• Storing C_{6}^{-} ions in an electrostatic ion storage ring.
• Detecting visible photons emitted from thermally populated electronic excited states.
• Analyzing the temporal profile of detected photons synchronized with ion revolution to distinguish RF.

Main Results:

• Successful detection of visible photons attributed to recurrent fluorescence (RF) from C_{6}^{-}$.
• Temporal correlation of photon emission with ion revolution provided distinct evidence for RF over normal fluorescence.
• The observed timescale of RF was significantly longer than the lifetime of the intact photoexcited state.

Conclusions:

• Recurrent fluorescence (RF) is a valid emission pathway from excited C_{6}^{-}$ ions.
• RF serves as a molecular cooling mechanism in isolated systems.
• This cooling process is likely significant for the stabilization of molecules in interstellar environments.