Electrostatic Accelerator Control System Design

As an important equipment of science research in material denaturation, nuclear physics, biophysics, and interactivity between ion beam and matter, the Ion Electrostatic Accelerator with large volume and complicated structure involves a lot of technique. Since the original control system adopted the mechanical manual operation, which is difficult to operate and the control precision is very low, it's necessary to be improved by automatic control technology. In the progress of improving the control system of the Ion Electrostatic Accelerator, The Ion Electrostatic Accelerator's particular electromagnetic environment brings great challenges to the applications of modern control technology and implements. The key problem in construction of the control system is how to realize the control path under the serious influence of static electric field, high voltage and high frequency electromagnetic field. The network link-circuit must be suit to the Ion Electrostatic Accelerator and satisfy the request of the system debugs and experiments. Reasonable protective measures should be taken to avoid the damage of the field controlling devices by multiplayer of high voltage and discharging current, and to ensure the transfer of the control signal and field collect signals.By considering the factors mentioned above, PROFIBUS-DP and SIMENSE S7-300 PLC are used to build up Ion Electrostatic Accelerator control network. The use of infrared link-circuit and optical fibre link-circuit enable the control signals and the field collect signals transferring accurately in the complicated electromagnetism environment.Since the control system is interfered strongly by the high static electric field, high voltage and high frequency electromagnetic field, it can not operates normally, and the control devices may be damaged. The main purpose here is to resolve the interference problem by compiling special software and adopting specific hardware measures. By considering the physical features of the Ion Electrostatic Accelerator, several anti-interference measures are used to solve the problem of electromagneticcompatibility in the control network. In the software design, aiming at the control problems in the system debugs, the software anti-interference methods are put forward. It is shown by debug that the control software can effectively resolve the problems such as the maloperation of relay, the motor working abnormally, and field signals difficult to collect. At the same time, by perfecting the system-monitoring function , the control system can not only display dynamically control flow and collect real-time experimental data, but also supervise the on-line working condition of field devices and the situation of interference. By analyzing the high-voltage stabilizing system of the Accelerator, we put forward the scheme of PID control of the high-voltage.