Study On Safety Interlock System Of Laboratory Tandem Electrostatic Accelerator

Tandem electrostatic accelerators have been widely used in the fields of irradiation mutation breeding,food irradiation preservation,irradiation sterilization of medical and sanitary products,irradiation and sterilization of industrial sewage,and modification of new materials and new devices.When the accelerator is running,the electrons,protons and other particle beams accelerated by the strong electric field will react with the accelerator components and targets to generate strong radiation.At this time,if people accidentally enter the experimental hall or approach the accelerator,they will cause radiation damage In severe cases,it may cause death,and the misoperation of personnel may also damage the accelerator system and cause serious economic losses.A stable and reliable safety interlocking system is very important to ensure the safety of personnel and equipment.For this reason,a large number of laboratory accelerator safety interlocking system technology research has been carried out at home and abroad.Due to the complex working environment of large-scale scientific installations and strict requirements on various parameters and indicators of the safety interlock system,the cost is very high,which far exceeds the industrialization requirements of related application industries.At the same time,the national compulsory standard of radiation safety has been improved continuously.It is urgent to develop a reliable,stable and low-cost safety interlocking system.First of all,on the basis of fully carrying out the research on the related technologies of the safety interlocking system,this paper deeply studies the setting basis and the control system composition of the safety interlocking system of the accelerator.The reliability of the redundant system is analyzed,the reliability of the simple and dual hybrid parallel redundant systems is compared,and the simple parallel redundant system that can meet the reliability requirements of the safety interlocking system is selected.The functional requirements of the parallel redundant system are analyzed in detail,and a protection method based on regional status is proposed.The parallel redundant system has good redundancy stability and safety.Secondly,with the on-site controller as the environment perception node and the intelligent management terminal,according to the actual environmental conditions of the tandem electrostatic accelerator irradiation center,a variety of hardware devices were analyzed and selected,and a test system verification model was built.The field control system with PLC as the core is optimized and designed,and the solid-state intermediate relay is innovatively used to realize parallel redundancy.According to the structure characteristics of data transmission layer,the LAN transmission and control network of secure interlocking system is constructed.Completed the development of the management and control software for the centralized monitoring platform of the safety interlocking system.It can realize data storage,human-computer interaction control and other work.Finally,the online test of the safety interlock system is carried out,which can effectively monitor the tandem electrostatic accelerator irradiation center device,realize the functions of search and clearing,emergency stop,alarm recovery,safety interlock mechanism and system hard redundancy.It conforms to the technical requirements of the national compulsory radiation safety standards and can effectively guarantee the safety of personnel and instruments.