First attempts to combine capillary tubes with photocathodes

We describe our efforts to combine glass capillary plates, operating as a gas amplification structure at approximately 1 atm, with photocathodes sensitive to visible light. Such capillary tubes are a by-product of the manufacture of Microchannel Plates and are commercially available. Preliminary tests indicate that gas gains >103 could be achieved without photon feedback. With two capillary plates in tandem (double-step multiplication) overall gains up to 105 were possible at counting rate <100 Hz/mm2. This approach may open new possibilities for detection of visible photons by gaseous detectors. Potential advantages are: high gains, large sensitive area, high granularity, and insensitivity to magnetic fields.