Speaker
Description
J-PARC E88/SA$\Phi$RE experiment aims at elucidating the chiral-symmetry restoration of the $\phi$ meson inside the nuclei by measuring its $K^{+}K^{-}$ decay in proton-nucleus collisions at 30 GeV/c. We have developed an MRPC with high-rate capability by warming the glass stack, aiming at precise time-of-flight measurements for $K^{\pm}$ identification. In E88/SA$\Phi$RE, we measure $\phi \rightarrow K^{+}K^{-}$ in proton-nucleus collisions at 1 MHz. The expected hit rate in the MRPC is 1 KHz/cm$^{2}$ at maximum. The MRPC consists of double glass stacks, each of which consists of 5 gaps with 6 glass sheets with a sensitive area of 230 mm $\times$ 750 mm. We achieved a timing resolution of $70-100$ ps in cosmic-ray and beam tests, and improved the timing resolution by a few % by raising the temperature from $\sim25^\circ$C to $\sim40^\circ$C. We also discuss the temperature dependence of the streamer contribution through waveform analysis of the signal. In this presentation, we will show the design of the MRPC for J-PARC E88, its performance in cosmic-ray and beam tests, and a plan for the J-PARC E88 experiment.