1,721,046 research outputs found
Photodesorption studies of alkali iodides in the fundamental absorption region
No full textThe photon-stimulated desorption yield spectra of alkali atoms and iodine atoms emitted from KI and RbI samples near the absorption threshold from 5 eV to 9 eV are discussed in terms of a three-step model for desorption. According to the photon energy, different transport mechanisms, with different diffusion lengths of the excited states are considered
Photostimulated desorption studies on potassium iodide
No full textIn this work we present the results of photostimulated desorption measurements obtained on KI under excitation in the fundamental absorption region. Yield curves of both potassium and iodine desorbed atoms are reported at several sample temperatures. We discuss the experimental results in terms of the optical constants and of the production efficiency of F and H centers in KI
Lifetime measurements of colour centres by multifrequency phase fluorometry
No full textThe first measurements of emission lifetimes in colour centres using a cross correlation phase and modulation fluorometer operating at the synchrotron radiation facility PULS (Frascati) are reported. Preliminary results on the F and F-aggregate centres in NaF are briefly summarized
B and C band excitation and emission spectra in KI:T1
No full textWe present the excitation spectra of KI:T1 measured in the region of the B and C absorption bands at several emission wavelengths and at 20 K, 80 K and 300 K. An accurate analysis of these spectra shows new properties of the excitation spectra, that we relate to the non radiative relaxation of the excited electrons towards the luminescent states
Design of a low-energy extended UV beamline for bending magnet radiation
No full textThe design of a beamline, covering the energy range from 5 to 200 eV, based on a double incidence spherical gratings monochromator designed for ELETTRA bending magnet radiation is described. The monochromator consists of two interchangeable sets of gratings working one at normal incidence and the other at grazing incidence, to cover the entire spectral interval. The photon energy range of interest is covered with five gratings (two at normal and three at grazing incidence) achieving a resolving power of the order of 10000 and a photon flux approximately 10 12 (photons/s/0.1% bandwidth/mm 2) at the sample position
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