Good performance of ECRIS by gas mixing, How ?

An ECR ion source has basic components i) plasma containing magnetic field (Ioffe field/min-B field. ii) microwave power input to heat electrons in slowly varying magnetic field in space through ECR process, iii) electron supply from the internal ionisation process and/or external source and iv) supply of neutral gas and/or metal vapour. The electrons on the cyclotron resonance surface of the magnetic field constantly get energy from the micro-wave injected in the plasma chamber. These energetic electrons impact first the neutral and then the ions with increasing charge state in step-wise manner vigorously and knock out the loosely bound electrons inelastically. So a plasma consisting of cold as well as hot electrons and thermal ions of various charge state is created and confined in the magnetic field by the plasma potential created by the loss of highly mobile electrons on the chamber wall. Some of the multicharged heavy ions (for the purpose of creation and extraction) get sufficiently high energy due to constant electron impact and are radially accelerated by the plasma potential. They strike the chamber-wall and sputter the wall material which cools the hot electrons which reduces the ion confinement and affects the plasma potential and multicharged ion production badly