Visualisation of high-current e-beams on solid surfaces

Up to day the visualizers of e-beams have essential disadvantages. They are rather complex, expensive, and/or average the recorded flux of electrons by surface. Therefore the task to find the new scintillators based on low cost, natural material for these purposes seems to be very important. To solve this task broad range minerals was examined. The natural specimens were investigated on high-current pulsed e-beam accelerators with the following parameters: currerit density from 10 to 1000 A/cm², energy from 100 to 300 keV, pulse duration from 2 to 50 ns [1,2]. It was found that high-intensive luminescence in visible spectral range with time duration to several tens of minutes is excited in such minerals as spodumen, calcite, apatite doped by Mn in the concentration range from 10⁻⁵ to 1 weight percents. The specimens with Mn concentration about 1 weight percentage appears to be the most suitable both by intensity and time of luminescence. The appearing of such luminescence allows one to observe the cross section of e-beam both during the action period and after it. The Fig. 1 presents the light “images” of e-beam on natural spodumen (Mn ∼ 1 weight %) at the distance: 0 − (1), 5 − (2), and 10 − (3) mm from output foil of e-beam accelerator recorded after two minutes of e-beam action. The increase of dimensions of light “image” results from e-beam cross section expansion. The decrease of its intensity results from of current density decreasing. One can see that intensity of luminescence depends on current density and it is possible to record cross sections of e-beam at different distances from the foil. The Fig. 2 presents the section of the same specimen along the longitudinal axis of e-beam. The dimension of luminous layer depends on the run length of electrons in the specimen and is determined by energy of electrons. So it is possible to determine the last one by measureme- t of dimension of this layer.