First Experiments with the IFUSP Microtron Injector.

The first accelerating structures of the São Paulo microtron accelerator presently deliver a continuous-wave 1.9 MeV electron beam, which can be used in atomic physics studies. An energy-analyzed beam line with focalization magnets, irradiation chamber, movable target system and Faraday cup was built. Here, we will describe the preliminary results of two experiments. In the first one, upper limits on K-shell ionization cross sections of Pd and Au atoms by electron impact were obtained. To this end, thin targets of these elements were irradiated with the beam impinging at 45° while the emitted Kα x-rays were recorded with an HPGe x-ray detector positioned at 90° with respect to the beam direction. The other experiment was the measurement of the bremsstrahlung energy spectra produced by the aforementioned targets in the same geometrical configuration but using an HPGe γ-ray detector instead. The latter experiment enabled the determination of the electron-beam energy as 1.909(5) MeV. [ABSTRACT FROM AUTHOR]