Test Results of a Thick Gas Electron Amplifier with a New Design

详细

The results obtained in the study of the avalanche process of electron multiplication in a thick gas amplifier of a new design are presented. The main feature of the device is the separation of the upper and lower parts of the amplifier by a gas gap with the preservation of the polyimide film as an insulator on the inner surface of the hole electrodes. The width of this gap can vary in the range of 0.1–1.0 mm, depending on the electrode size. With this separation, the surface leakage currents are absent between the electrodes and the charge is not induced on the inner surface of the gas-discharge gap. Due to this solution, it is possible to minimize the probability of both surface and volume streamer phenomena that turn into a Geiger or spark discharge. As a result, a pulse amplitude of a few volts was measured across a load of 50 Ω in a gas mixture of Ar + 20% CO₂ when the detector was irradiated with a ⁹⁰Sr β source.