Study on the rate capability of MRPCs assembled with thin glass

With the increase of accelerator luminosity, the rate requirement for timing MRPC becomes important. Usually MRPCs are assembled with ordinary glass plates of 1.0 mm or thicker, but their rate capability is only about 200 Hz/cm², which cannot afford to the future high rate requirement. DC model and a two dimensional resistor network model suggested that the rate capability of MRPC is largely dependent on the thickness of glass electrode. Three MRPCs based on three different thickness of thin float glass plates were assembled in our Lab to study the rate effects. The cosmic rays test result shows that those three MRPCs can work properly in a low rate environment. The X-rays test results suggested that the thinner the electrode the higher counting rate can be obtained by MRPC. Uniformly irradiation under a 1 GeV/c deuteron beams was carried out at the Nuclotron accelerator at the Joint Institute for Nuclear Research. MRPCs assembled with three thickness (0.7mm, 0.5mm and 0.35mm) glass can afford particle rate up to 500 Hz/cm², 0.75 kHz/cm² and 3.2 kHz/cm², respectively. In the mean time, a time resolution of 75ps was remained. What´s more, the results indicate that reduce the thickness of glass electrode is a promising way to improve the rate capability of MRPC.