A new type of proportional counter using a capillary plate

We have developed a new type of proportional counter with the capability of fine position resolution and high gas gain. It consists of a bundle of fine glass capillaries with electrodes on both the inlet and the outlet. The capillaries are 100 μm in diameter and 800 μm in length and gas multiplication was found to occur in each capillary with an applied voltage between the inlet and the outlet. The resulting proportional counter was found to operate up to a gain of 104 without the onset of breakdown and had an energy resolution of 26% for 5.9 keV X-rays at a gas gain of 7000. Its detection efficiency was identical to a conventional single wire device.