介绍了为在放射性束流线上开展精确的散射和反应实验中 ,对入射束流的角度和有效数目等进行在线监测而设计制造的低气压多丝正比室 .它透射性好 ,不干扰束流 ,并方便在真空环境中工作 .测量表明 ,它的位置分辨率约0 5mm .对 2 0— 3 0MeV/u的低Z的放射性束流有着大于 90 %的位置探测效率 ,适用于中能次级束实验靶前的束流定位及在线监测 ,也可用在靶后测量出射带电粒子的角度 A low-pressure multi-filament proportional chamber designed and manufactured for the purpose of conducting accurate scattering and reaction experiments on the radioactive beam lines, on-line monitoring of the angle and effective number of incident beam currents, etc. is well-transmissive and does not interfere with the beam Flow, and easy to work in a vacuum environment. Measurement shows that its position resolution of about 0 5mm. Low 20 to 30MeV / u of low-Z radioactive beam has more than 90% of the position detection efficiency for medium energy Beam positioning and on-line monitoring of the target before the secondary beam experiment can also be used to measure the angle at which outgoing charged particles emerge