Study Of Two-dimensional Position Sensitive Detector On RIBLL

With the further development of Radioactive Ion Beam Physics both at home and abroad,the focus of current study has been turned to the nuclei,which with low Z value but neutron rich or proton rich,Such as He6?8He?9Li?11Be?12Be?14Be?C9?10C and so on.The low production of these nuclei at Radioactive Ion Beam Line in Lanzhou(RIBLL),which makes a higher requirement for the detection efficiency of the detector.Double-layer Multi-Wire Proportional Chamber(MWPC)based on LC delay circuit,which is a high-performance gas detector,is developed to improve the efficiency of detecting the intermediate and high energy radioactive ions,measure the position of projectile nucleus before target nucleus and determine the flight direction of reaction product after target nucleus.At the same time,Double-layer MWPC based on LC delay circuit plays an important role in improving the transmission efficiency of beam,separating and identifying beam components.A double-layer MWPC with 80100 ?mmmm active area has been developed to measure the position of intermediate and high energy radioactive ions at 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 ?mand 154.0 ?musing a555.9keVFe-keV X ray,respectively.While the position linearity of X and Y directions are as good as 0.999 for whole sensitive area of the detector.The developed double-layer MWPCs have been put into use in RIBLL II experiments,their performance is satisfactory.