Production Of Intense High Charge State Refractory Metallic Ion Beam

Since the end of 1980s,a number of ECR ion sources with variable design have been successfully built in many countries and regions successively,as a result of their outstanding performance in the application of heavy ion accelerator technology and experiments of nuclear physics.The type of ion source has been evolved from the traditional 1st generation to the latest 3rd generation complex with superconducting technology.The ion beam species have also been enhanced from only few low and medium charge state gaseous ions to high charge state ions up to uranium.At room temperature,most of metals are solid.They have to be converted into gases in order to meet the needs of production of these metallic ion beams in an ECR ion source.The typical methods to produce metallic ion beams in ECR ion source are micro-oven,plasma heating,sputtering,laser ablation and MIVOC(Metallic Ion from Volatile Compounds),and so on,amongst which the micro-oven is so far the most reliable method in the production of intense high charge metallic ion beams.There are mainly two types of micro-oven in use,i.e.high and low temperature oven.High temperature oven is especially used for metals with melting temperature over 1500 ?,such as cobalt,titanium,vanadium,platinum,uranium dioxide.In this thesis,I designed and tested an oven aiming to achieve a temperature as high as 1800?2000 ? for the application with an ECR ion source in refractory metallic ion beam production.This study uses ANSYS to simulate and analyze the temperature distribution on a tantalum crucible of high temperature oven and its Lawrence force under the strong magnet field in an ECR ion source.The thermal stress at high temperature has also been estimated with the simulation code.According to the test,the deformation of tantalum crucible over 1800 ? during the off-line test is consistent with the ANSYS simulation results,which puts forward an improved scheme.And the improved resistor heating micro-oven can remain stable at 1500 ? for 48 hours and 1846 ? for more than 6 hours in the off-line test.We test metals such as Nickel and Lead in the on-line test and get 25 e?A of Ni19+and 185 e?A of Pb28+.This results show that the resistor heating oven can work in the magnet field of ECR ion source.Then analyze the problem of resistor heating micro-oven according to the test.At the mean time,design inducting heating oven and electron beam heating oven.The results of off-line tests show that they can both achieve more than 1800 ?.The on-line test of electron beam heating oven shows that it can't work as usual because of the Lorentz force in the ECR ion source.It'll be modified in the near future.