We have obtained fast loading of a rubidium magneto-optical trap and very high collection efficiency by capturing the atoms desorbed by a light flash from a polydimethylsiloxane film deposited on the internal surface of a cell. The atoms are trapped with an effective loading time of about 65 ms at a loading rate greater than $2\times {10}^8$ atoms per second. This rate is larger than the values reported in literature and is obtained by preserving a long lifetime of the trapped atoms. This lifetime exceeds the filling time by nearly two orders of magnitude. Trap loading by light-induced desorption from siloxane compounds can be very effectively applied to store and trap a large number of atoms in the case of very weak atomic flux or extremely low vapor density. It can be also effectively used for fast production of ultracold atoms.

The light-induced desorption and diffusion of alkali-metal atoms in organic films are interesting fields of investigation. An impressive demonstration is given by the recently observed light-induced atomic desorption (LIAD) effect, where a huge alkali-metal atom desorption from siloxane films, previously exposed to atomic vapors, is induced by weak and nonresonant light. In this paper, experimental data and a one-dimensional theoretical model of the effect are presented. The model gives a good description of the vapor density dynamics by taking into account both the atomic diffusion inside the coating and the surface desorption. General equations are reported and discussed within the limits of experimental interest. The potential barrier at the vapor-surface interface and the activation energy for Rb in (poly)dimethylsiloxane have been determined.

Excitation functions for ${}^{208–211}\mathrm{Fr}$ isotopes produced in the ${}^{18}\mathrm{O}+{}^{197}\mathrm{Au}$ fusion-evaporation reaction have been measured at $E_{\mathrm{lab}}=75\text{–}130$ MeV via characteristic $\alpha$ decays by means of an electrostatic deflector and a semiconductor detector. Data have been compared with calculations giving barrier-passing (capture) cross sections and probabilities of the compound nucleus decay into different channels according to the standard statistical model.

We observe reversible light assisted formation and evaporation of rubidium clusters embedded in nanoporous silica. Metallic nanoparticles are cyclically produced and evaporated by weak blue-green and near-infrared light, respectively. The atoms photodetached from the huge surface of the silica matrix build up clusters, whereas cluster evaporation is increased by induced surface plasmon excitation. Frequency tuning of light activates either one process or the other and the related changes of glass transparency become visible to the naked eye. We demonstrate that the porous silica, loaded with rubidium, shows memory of illumination sequences behaving as a rereadable and rewritable optical medium. These processes take place as a consequence of the strong confinement of atoms and particles at the nanoscale.