Cylindrical Electrode-Less Gas Electron Multiplier

70906 The determination of particle energy and path angle with high precision is required for high-energy particle physics. Of the possible approaches to this requirement, microstrip detectors provide optimum data, but have limited count rate and gain and high costs. Gas electron multipliers would be a candidate technology, but they require photolithography and thick metal coatings, which contribute to less than ideal performance at inflated cost. This project will fabricate improved gas electron multipliers (GEM) at lower cost with better performance. New micromolding techniques will be used to avoid photolithography, and an ion beam surface treatment will be employed to avoid metallic layers. Phase I will develop micromolding techniques to ¿cast¿ polyimide sheets with nominaly optimal GEM parameters: 0.05mm thickness with cylindrical holes of 0.070mm diameter. Low energy ion beam radiation will be used to increase surface conductivity. Samples will be tested on radiation facilities. Commercial Applications and Other Benefits as described by the awardee: The new process should reduce costs for GEM detectors by a factor of ten, allowing use in large experiments for high energy physics. Also, at low cost, the detector would have potential medical applications for fine resolution x-ray imaging.