E. Melero Garcı́a

Fluorescence emission following core excitations in the water molecule

Photon-induced fluorescence spectroscopy has been used to study the fragmentation of the water molecule at the O 1s is edge. Fluorescence emission has been observed from the neutral fragments H, ...

Neutral dissociation of superexcited states in nitric oxide

Near-infrared dispersed fluorescence measurements of 13 different atomic multiplets of neutral atomic fragments from photon induced neutral dissociation processes in NO are reported. For excitation ...

Fluorescence study of doubly excited states of molecular hydrogen

Photodissociation of molecular hydrogen has been investigated by means of fluorescence spectroscopy using synchrotron radiation. Balmer-alpha emission from atomic hydrogen photofragments was collec ...

Autoionisation of superexcited states in N2 to the N2+ B state

Vibrationally resolved N2+ (B–X) (1–2) and (0–1) emission bands were recorded after photoexcitation of N2 in the 20–46 eV energy range. The branching ratio between these transitions reveals strong non-Franck–Condon effects. Ab initio calculations using a configuration interaction method based on Kohn–Sham orbitals indicate that the autoionisation of certain superexcited states is responsible for some structures present in the branching ratio curve.

Experimental station for gas phase fluorescence spectroscopy

The details of an experimental setup for gas phase atomic and molecular fluorescence measurements using synchrotron radiation are described in this article. The most significant part of the apparatus is an optical arrangement, which allows for simultaneous measurements of dispersed as well as total fluorescence intensity using an effusive gas jet and an inbuilt gas cell assembled in a convenient plug and measure configuration. The first measurements concerning fluorescence of the N2 molecule around the N 1s edge obtained with this setup are presented.

Vis?UV fluorescence studies of fragments resulting from the relaxation of molecular core hole states

The absorption of soft x-ray radiation induces neutral and ionic core hole states in molecules. The relaxation of such states typically leads to a multi-step process, at the end of which photons in the visible and UV range can also be emitted from fragments. In this paper, we present results on Balmer and Lyman emission that originates from excited H atoms produced at the K-edge of the water, ammonia and methane molecules. Dissociation pathways leading to fluorescence emission are discussed.

The npσ, π to EF emission systems in D2 studied by selective excitation

The npσ 1Σ+u and npπ 1Πu states in D2 have been selectively excited using monoenergetic synchrotron light in the range of 13.97–15.84 eV and the subsequent dispersed emission to the EF 1Σ+g state was observed using a grating spectrometer. In total, 18 emission bands from the levels n = 3–6 were studied and rotationally analysed. The intensities of the P and R branches relative to the Q branch were found to vary strongly in the npπ 1Π+u–EF1Σ+g bands indicating the existence of predissociations of npπ 1Π+u levels above the dissociation limit D(1s) + D(2l).