Recently the momentum distributions of recoil ions were measured in the single ionization of neon with electron impact by utilizing the longitudinal reaction microscope at the Institute of Modern Physics, CAS.

The extremely large momenta of recoil ions Ne+ were firstly discovered and the reasons resulted in the characteristics of the momentum distributions of the recoil ion were well probed (see Fig 1.).

By comparing the results with those of electron-neon elastic scattering (see Fig 2.), the existence of strong projectile–target-core interaction which plays an important role in the Ne(e, 2e) reaction was firstly confirmed in view of the recoil ions, as well, a two-step collision mechanism was also explored.

The results were published in Physical Review A82, 052702(2010).

Fig. 2. Comparison of the singly differential cross section of Ne(e, 2e) reaction(left column ) and that of e-neon elastic scattering(right column). (IMAGE/IMP)