Transmission diffractive patterns of large microchannel plates at soft X-ray energies

In this contribution we compare experimental and theoretical diffractive patterns of Micro Channel Plates (MCPs) in transmission. We evaluate the transmission efficiency of different optical devices at different energies of the primary X-ray radiation in the normal incidence geometry. Data were collected performing angular scans of both the MCP device and of the detector in the range of a few degrees. We analyzed MCPs of 33 mm and 20 mm diameter and ~300 µm thickness, having circular micro-channels of 3.4 µm directed normal to the MCP surface. Quite symmetric patterns of increasing complexity from high to low photon energy have been collected. Their shape and intensity are in reasonable agreement with preliminary simulations.