Be-7 radioactive beam production at CIRCE and its utilization in basic and applied physics

A pure 7Be beam with an energy E = 1 8 MeV is available for nuclear and applied physics at the 3 MV Pelletron tandem accelerator CIRCE in Caserta. The beam is produced using an offline technique. Typical analyzed beam intensities are about 2 ppA, using cathodes with an activity of the order of 200 MBq. The 7Be implantation has been used for both fundamental nuclear physics and applied physics. In particular, different metals have been implanted with 7Be in order to study the influence of the chemical composition and of the number of quasi-free electrons of the host material on the 7Be half-life. In the field of applied physics, the 7Be implantation turns out to be very interesting for wear measurement. In fact, in this case 7Be is used as a depth-sensitive tracer. The continuous detection of the sample activity during the wear allows a high sensitivity measurement of wearing speed. The 7Be beam production at CIRCE, the implantation procedure and the results obtained from the 7Be half-life measurements and the wear characterization of implanted steel samples are described.