• R. Taniguchi, T. Kojima, S. Okuda, R. Sasaki
  Osaka Prefecture University, Sakai

Energetic electron beams higher than several MeV occasionally induce direct nuclear reactions with the target nuclei. These processes are attributed to the quasi-elastic scattering of electrons (e,e') with the target nuclei and similar to the photo-nuclear reactions. These reactions are considered to be useful for the non-destructive analysis of heavy elements such as U and Th. In addition, a two-dimensional analysis is realized only by scanning of electron beam. On the other hand, the huge X-ray burst caused by the bremsstrahlung with the electron pulse bombardment is the most harmful phenomenon for the radiation measurement system. In this study, an ultra low intensity electron beam was used for relieving the problem, which has been developed by modifying an electron linear accelerator. The minimum beam charge about several aC/pulse has been achieved at the present. Consequently, the neutron emitted by Pb(e,e'n)Pb reaction was measured successfully by the use of the low intensity beams. The linearity between the neutron count and the concentration of Pb in the target was verified experimentally.