| 摘要 |
<p>1,252,364. Recording tracks of particles. COMMISSARIAT A L'ENERGIE ATOMIQUE. 12 Feb., 1969 [26 Feb., 1968], No. 7670/69. Addition to 1,133,682. Heading G6P. An image of a radio-active source is obtained by localizing the emitted beta particles and X and gamma ray photons, in a gas filled spark chamber. Organic vapour is added to the gas and this is progressively destroyed as the sparks are generated, so limiting the life of the chamber. To limit the dead time of the chamber and increase its life, an external spark quench and control circuit is provided. The control circuit may be designed to cause the chamber to operate in either the spark discharge or electronavalanche condition. In the spark condition, the signal developed at the spark chamber grid is amplified at two avalanche-connected transistors and applied to the grid of a tetrode coupled across the spark chamber to function as a short circuit. Where the spark chamber functions in the avalanche condition the grid signal is amplified before application to the short circuiting arrangement in an amplifier incorporating a wide pass-band, low noise field effect transistor.</p> |
