Speaker
Description
Highly excited molecules and clusters can emit visible and infrared radiation from thermally excited electronic states. This radiation, known as recurrent fluorescence, is particularly intense for carbon clusters and carbon-based molecules due to their high stabilities which allows them to store large amounts of excitation energy and thereby have the possibility to promote electrons to optically active excited states.
Photon emission time constants range from the typical infrared timescales of milliseconds down to a few tens of microseconds, depending critically on the electronic structure of the system. The thermal photon emission channel provides an efficient, but very system-dependent cooling of the molecules/clusters and can as an important stabilizing factors in the collision-poor interstellar medium.
Recurrent fluorescence radiation has been studied at several electrostatic storage rings. In these devices the radiative cooling is measured in parallel with unimolecular decays or thermal electron detachment from anions. I will present measurements from such devices on radiation from fullerenes, from pure carbon cluster ions for sizes below the fullerene size limit of $N\approx30$, and for carbon-based molecules of astrophysical interest.
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Int. Rev. Phys. Chem. 38 (2019) 405-440
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