The Design For4MeV Ionelectrostatic Accelerator Stablizing Voltage System

Single ion microbeam is the most advanced technology, which realizes the singleion/single cell radiations. It has become a strong scientific research platform withwide applications in biology, physics, microfabrication, environments&healthy, spaceradiation simulation, and so on.Positioning precision is the most important parameter of the single ionmicrobeam. There ale lots of factors affecting the positioning precision, in which theenergy instability is the main one. The energy instability mainly comes from theterminal voltage stability of the electrostatic accelerator．The energy instability affectsthe stable run time as well.This dissertation analyzed the terminal voltage stability of the electrostaticaccelerator in the4MeV ionelectrostatic accelerator facility and developed allterminal voltage control system by Generating Voltmeter(GVM) method. At last, theterminal voltage stability of the accelerator has improved; the positioning precision ofthe4MeV ionelectrostatic accelerator has increased too.The main work includes：1) Design of sharp cutoff shunt voltage regulator(pentode): first design a circuitwhich was used to detect the parameters of6EL4, then transfer characteristic curveshad been drawn.2)Analysis the principles of terminal voltage stability: after a few comparison ofsome voltage stability methods, the analysis of the control of the terminal voltage ofthe accelerator, aiming at the working principle of GVM, including its structure,principles and sample method．3) Circuit of ionelectrostatic accelerator of terminal voltage stability: the circuitdesigned for the terminal voltage control system, including50Hz notch filter,lowpass,rectifier, band filter, error amplifier, et al.tests on them. Analysis is done for theinfluences of the terminal voltage instability on the beam energy instability, beamradius and single ion positioning precision．...