Aerogel layer embedded gaseous electron multiplier

The MoNA Collaboration and Detector Group at the Facility for Rare Isotope Beams is developing a novel gas-avalanche structure for high gain operation and suppression of ion/photon feedback to enable the development of Gas Photomultipliers (GPMs) for the visible spectral range in continuous DC operation. The proposed concept consists of a hole-type gaseous multiplier with an inner flat electrode made of a thin aerogel layer supported by a fine mesh. The aerogel acts as a charge filter, allowing primary electrons to reach the multiplication region while blocking avalanche ions from impinging on the photocathode layer. The sensitive photocathode is thus protected from secondary harmful effects induced by ion back streams and its lifetime extended. We will describe this project and provide an update on its status.