Ion feedback suppression using inclined MCP holes in a "single-MCP+Micromegas+pads" detector

We show that the ion backflow to photocathode can he completely suppressed if one uses inclined MCP holes in a presence of magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, the first one is a single MCP (microchannel) plate, and the second one is a Micromegas with pad readout. The paper compares relative merits of gaseous and vacuum-based MCP detectors. We are aiming to develop a gaseous detector with the bialkali photocathode.