Recent advances in (e,3e) and e,(3-1)e experiments

The experimental advances in the study of electron impact double ionization using double coincidence e,(3-1)e or triple coincidence (e,3e) techniques are reviewed. The recent advent and extension of multianalysis and multidetection systems have allowed a second generation of(e,3e) spectrometers to be born Their most pertinent characteristics are described. Illustrative results from both e,(3-1)e and (e,3e) experiments are discussed, showing all the promising potential of these highly differential studies for the detailed investigation of the fundamentals of the double ionization process.