用于放射性束流实验的低气压二维位置灵敏多丝正比室

Low Pressure Two Dimensional Position Sensitive Multiwire Proportional Chamber for the Radioactive Ion Beam Experiment

为在放射性束流线上进行核反应研究而研制了灵敏面积为50mm×50mm的二维位置灵敏的低气压多丝正比室。低气压多丝正比室为穿透式,在真空中使用,工作气压为800Pa,透射性好,不干扰束流。放射性束流在束测试结果表明:它的x、y方向的位置双径迹分辨为1mm;对30～40MeV的低Z放射性束的探测效率大于80%,适用于中能次级束实验中入射束的定位和反应中产生的带电粒子出射角度的测量。

Low pressure two dimensional position sensitive multiwire proportional chamber (MWPC) was developed to be used to study the nuclear reaction induced by radioactive ion beam. Each detector has a 50 mm × 50 mm sensitive area and consists of three grids (x-position, cathode, y-position). The position was determined through delay line readout mode. The detectors have good beam transparency and are also adequate to be used in vacuum. The MWPC was tested at a pressure of 800 Pa of n-heptane and a bias voltage of 720 V. The test results indicate that two track position resolution of the chamber is Δx = Δy = l mm and position determination efficiency is larger than 80% for the low Z particle at intermediate energies. This kind of chamber can be used to determine the direction of the incident particle and to detect the emitting angle of the reaction products.