Centro Nacional de Aceleradores

3MV Tandem Accelerator

The first accelerator at the CNA is basically an analytical tool. It accelerates protons, alpha particles and a wide variety of ions by means of a high potential gap, till 3 millions of volts (MV).
The first accelerator at CNA was a Pelletron 3 MV Tandem, model 9SDH-2, made by National Electrostatics Corporation (NEC). It is primarily focused on material characterization and modification by means of IBA techniques and ion implantation, as well as to the study and development of nuclear instrumentation, especially radiation detectors.

Ions are produced by three ion sources. The first one is based on radiofrequency techniques (Alphatross) and generates negative ions from gases (H, He, N, ...). There is also a caesium sputtering source (SNICS) which produces negative ions from solid samples. The most recent one is a Duoplasmatron source, which is very reliable and provides a high-brightness beam. The sources are connected by ports to an injection magnet that selects the desired ion mass.


In the two-pellet chain tandem accelerator, the selected ions are accelerated with a maximum terminal voltage of 3 MV. The beam line, which is situated after the accelerator, includes several instruments for focusing, steering and monitoring the beam. At the line end, the beam can pass directly to the 0° line or it can be deflected by the switcher magnet towards one of the five beam lines.


Photons and particles are detected using standard detectors: SiLi and LEGe from Canberra, an Ortec HPGe, a NaI(Tl) detector and ion-implanted silicon detectors.


tandem 3mv