The Developing Of Large Sensitive Parallel-Plate Avlanche Counter

Accelerators and radioactive ion beams are very important devices for scientific studies, on the base of which some nuclear experiments ask for suitable nuclear detectors to measure some basic information of particles such as time, position and energy. With the development of science and technology, we need higher standard of nuclear detectors.To satisfy the need to monitor the time and position information of fission fragments in RIBLL, we need a kind of detector that is time and position sensitive. Fission fragments have a large energy loss going through PPAC, which causes a large signal.And in addition, experimenters give a demand that the space solid angle of the detecting area should be 20°to 120°. After all, we decide to develop a kind of large-area position sensitive parallel plate avalanche counter(PPAC).Large-area PPAC consists of three plates, which is suitable for the detecting of large mass particles. The sensitive area is 244×284 mm2.The gap between each plate is 3mm.The diameter of the wire is 20μm and the gap between interfacing wires is 1mm. The cathode plane is made of 1.5μm-thick Mylar foil. The method of position readout is delay-block. The filling gas is isobutane. We have done a primary test in the lab which shows the result that the position resolution is better than 4mm and the time resolution is808 ps when tested together with a Si detector, when working at a gas pressure of 4.5mbar.The efficiency is better than 90% when it is tested online with fission fragmentsThe main work of this thesis contains:Acknowledging the details of the principals of gas detectors and PPAC and the development of PPAC; grasping the technology and procedure of developing large-area PPAC; learning to test PPAC in labs; take part in large nuclear experiments; handling some skills in manipulating data.