Ultra-high spatial resolution in micron scale achieved by a practical cascade high energy electron radiography in HERPL

As a new scheme, High Energy Electron Radiography (HEER) was considered as one of the novel mesoscale diagnostic methods for high energy density matter (HEDM) because of powerful penetration, high space-time resolution and large density dynamic diagnosis range. In this work, we R&D a practicle cascade HEER composed of a electromagnetic beamline and a permanent magnet HEER in High Energy Electron Radiography Research Platform in Lanzhou (HERPL). The field of view of the cascade HEER is about Φ3mm, and its total length is half that of the electromagnetic HEER with the same magnification. 50 MeV electron beams with picosecond pulse width bunch were used to image a TEM grid to study the spatial resolution. The excellent result was obtained with spatial resolution about 0.6 μm. In addition, electron bunch train and ultra-fast imaging acquisition system prepared for dynamic HEER were studied in this paper.