Système d'acquisition de données à registres dynamiques «MOS» comme mémoire-tampon

Conclusion La solution décrite comme mémoire-tampon en minimalise le volume, la dissipation et le prix. Elle est facilement extensible, l'adressage est simple et flexible, le temps d'accès convient bien à l'acquisition de données hors ligne.Ce travail est partiellement financé par le Fonds National Suisse pour la Recherche Scientifique.     

Photoablation and microstructuring of polyestercarbonates and their blends with a XeCl excimer laser

Received: 23 October 1997/Accepted: 18 November 1997     

First direct measurement of the total cross-section of 12C(α,γ)16O

The total cross-section of ¹²C(α,γ)¹⁶O was measured for the first time by a direct and ungated detection of the ¹⁶O recoils. This measurement in inverse kinematics using the recoil mass separator ERNA in combination with a windowless He gas target allowed to collect data with high precision in the energy range E = 1.9 to 4.9 MeV. The data represent new information for the determination of the astrophysical S(E) factor.     

Electronic states in solids investigated by means of synchrotron radiation

Recent progress is reviewed in the investigation of deep valence and core states in solids by means of continuous and intense vacuum ultraviolet radiation from electron synchrotons and storage rings. The basic theoretical concepts involved in the interpretation of spectroscopic data for the range from the ultraviolet to the X-ray region are outlined and a short account is given of the experimental aspects of work with synchrotron radiation. In addition to optical reflectivity and absorption measurements the advantages are pointed out of investigating photoelectric yield, energy distributions of photoemitted electrons and luminescence excitation spectra with a tunable light source. A selection of more recent experimental results is given in order to illustrate the following topics concerned with the electronic structure of solids: band structure effects, localized excitations such as excitons, decay processes of elementary excitations, unoccupied surface states, surface excitons and electronic states of adsorbates, and many-body effects. The common origin and close correspondence of many features of inner-shell absorption spectra from atoms, molecules and solids is pointed out.