Ion Temperature Measurements On The EAST Using A Retarding Field Analyzer

The development of modern society can’t do without energy and world energy demands are increasing year after year,most of which are satisfied by burning fossil fuels like petroleum,natural gas and coal so far.The normal fossil energy on earth is non-renewable and limited while the demand of energy for human is never-ending,fossil fuels will be run out one day.The burning of fossil fuels causes environmental issues like greenhouse effect and acid rain,too.In view of this,new methods of sustainable energy need to be found.The use of nuclear energy is a possible option to solve energy problem.Nuclear energy can be created by nuclear fission or nuclear fusion,and nuclear fission has been used to generate electricity.Compared to nuclear fission,nuclear fusion is cleaner and more efficient.However,it is difficult for fusion to happen.High temperature is needed for nuclei to overcome the Coulomb repulsion between them.At such high temperature,the gas used as fuels for fusion will be ionized and then a plasma is created.How to confine the high temperature plasma is still a problem.Magnetic confinement and inertial confinement are two methods to confine the plasma.Tokamak uses magnetic fields to achieve the confinement and is one of the leading contenders for a working fusion reactor.The theme of this paper is the measurement of ion temperatures of the edge plasma in tokamak by using RFA probe.An RFA probe is designed and constructed,then the probe is mounted on EAST tokamak in Chinese Academy of Sciences,Hefei to measure the ion temperature during the discharge.The ion temperature in the plasma edge of fusion devices is an important parameter and RFA is a practical tool to measure the ion temperature.There are noises in the experiment inevitably.Influences of the noises are investigated by experiment and simulation.There are still some unsolved problems in the experiment and further study is needed in future works.