Optical Imaging Capillary Plate Gas Detector
A capillary plate (CP) gas detector with a CF4 gas mixture of argon and pure xenon has been successfully operated as a visible and near-infrared (NIR) scintillation proportional counter. Gas gains of up to 104 can be achieved using these gas mixtures. The scintillation light emitted during the generation of electron avalanches can be observed using a photomultiplier tube (PMT) and a compact optical imaging system which consists of a CP gas detector and a cooled charge-coupled device (CCD) camera coupled to lens optics. Using this optical imaging system, clearer images of X-rays have been obtained with the above gas mixtures. The successful operation using these gas mixtures has allowed us to realize a novel imaging device with a CP for medical imaging and gaseous PMTs sensitive to visible light.