A Lightproof Screen For Time-Projection Chambers With Large Multiplication Coefficients And Photocathodes

A lightproof screen for time-projection chambers is described. It attenuates the photon flux from the anode region to the drift, volume and is simultaneously transparent for ionization electrons drifting from the chamber volume to the anode. The use of this screen in time-projection chambers with large electron multiplication coefficients or photocathodes makes it possible to eliminate the photon feedback effect, which results in the appearance of afterpulses and breakdowns.