摘要: 描述了为兰州放射性粒子束流线（RIBLL Ⅱ）上测量束流径迹而研制的一种基于LC延迟电路的双层多丝正比室（MWPC）。该探测器的探测灵敏面积为100 mm×80 mm，位置信号由阴极丝引出并通过LC延迟电路读出。探测器由两套完整的多丝正比室组成，每套的阳极丝夹在两层平行的阴极丝之间，阳极丝和阴极丝相互垂直。两套阴极丝相互垂直给出入射粒子的二维位置信息。为了增大感应信号以提高探测效率，将每套位置对应的阴极丝合并成一路接入LC延迟电路。用⁵⁵Fe-5.9 keV X射线源均匀照射探测器的灵敏区域，测试表明其具有良好的位置灵敏一致性。用X射线源通过准直狭缝扫描整个探测器的灵敏区域，得到X，Y层的位置线性度均好于0.999；其位置分辨（σ）分别为199.9 μm和154.0 μm，目前，该探测器已成功用于RIBLL Ⅱ的实验中。


A double-layer Multi-Wire Proportional Chamber (MWPC) with 100 mm×80 mm active area has been developed for Radioactive Ion Beam Line in Lanzhou(RIBLL Ⅱ). The position information has been obtained by a LC delay circuit readout method. Being called of double-layer MWPC, it is composed of two full MWPCs, each consists of an anode plane sandwiched between two parallel cathode planes, anode wires and cathode wires are perpendicular to each other. In order to improve the detection efficiency, the cathode wires of corresponding position are combined to enhance inductive signal. The cathode wires of two full MWPCs are orthogonally placed to give two coordinates of the incident particles. The sensitivity uniformity is also found to be relatively good and the position resolution of X, Y direction are measured to be 199.9 and 154.0 μm using a ⁵⁵Fe-5.9 keV X ray, respectively. The position linearity of X, Y direction are as good as 0.999 for whole sensitive area of the detector. The detector has been used successfully on the experiment at RIBLL Ⅱ.