羊八井ARGO实验RPC性能(英文)

Study on the Performance of the YBJ-ARGO RPC

羊八井ARGO实验采用全覆盖式RPC阵列探测小型空气簇射事例 ,本文报告了在羊八井高海拔条件下RPC的工作性能 ,包括电流、效率、读出条重数和时间分辨随高压的变化 .通过在气体中添加SF6组分和调节接收系统下拉阈值可以有效遏制由于探测器地浮动引起的伴随多重数 .

YBJ-ARGO experiment is designed to detect small size air showers at an energy threshold of～100GeV using a full coverage RPC array. High detector efficiency, good time resolution (～1ns) and low strip multiplicity (～1.2) are needed to meet the experiment requirements. Performance of RPC, including the above mentioned detector parameters together with the RPC current, is studied at high altitude (4300m a.s.l.) with a normal RPC gas mixture, under which high strip and hit multiplicity effect is observed due to the float of the CHAMBER mass reference which creates concomitant strip multiplicity when a large streamer develops in the CHAMBER. By adding SF 6 component into the gas mixture to limit the streamer development together with adjusting the pull-down threshold of the signal-receiving system, the mass-reference-float effect is effectively eliminated, thus achieving lower strip multiplicity and lower working current under the same working high voltage.