High Counting Rate Timing Resistive Plate Chamber

Timing resistive plate chamber with thickness of 70~mg/cm2 is constructed as alternative to plastic scintillation detector in particle physics. Chamber gives high rate capability up to 1MHz per cm2 in sensitive area 10 cm2. To avoid contamination and damage under strong ionization the gas forced jet device and cleaning circulation system including nuclear filtres are applied. Chamber consists of anode which is 5 m-polyimid film coated cuprum and gold and cathode which is 330 m silicium plate with diamand-like film on surface. Gap between cathode and anode is 0.2 mm. Fast preamplifier is connected to anode. Signal from preamplifier feeds constant fraction discriminator with time reference of 20 ps. Negative power supply is connected to cathode. Time between signal from plastic scintillation detector and resistive plate chamber is measured with time reference of 20 ps. Four-component gas mixture of noble gases containing 73 %C2H2F4, 20 %Ar, 5 %CO2 and 2 %SF6 is circulated through chamber. Test of chamber is performed with radioactive source 90Sr (90Y). Time resolution 270 ps is obtained at maximum possible counting rate.