We have developed a gas electron multiplier (GEM)-based time projection chamber (TPC) for the H-dibaryon search experiment at J-PARC. High-rate K− beam particles enter a TPC gas volume of approximately 0.2 m3, in a direction perpendicular to the electric field. A long-rectangular hollow section is located inside the TPC volume to accommodate a diamond target. We commissioned the TPC using 230-MeV protons with beam rates of up to 1 MHz. The TPC data acquisition system collected 5768 pad signals in full readout mode, with almost 100% efficiency, at a preset trigger rate of 230 Hz. We operated the TPC in an Ar/CH4 gas mixture (90/10) without a magnetic field. The spatial resolutions on the pad plane are measured to be 400–700μm, which correspond to 230–300μm in a magnetic field of 1 T. We confirmed high tracking capability at beam rates of up to 1 MHz.
|ジャーナル||Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|
|出版ステータス||Published - 2019 10月 1|
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