Ion-source plasma

The properties of ion-source plasma are determined from requirements of high quality and quantity ion beam extraction: the plasma density ranges between 5 x 109 and 5 x 1012 cm-3, the ion temperature should be within several eV, and the uniformity of plasma density within several %. In order to obtain such high density plasma, firstly, ionizing electrons should be effectively confined by crossed electric and magnetic fields or cusp magnetic fields. Secondly, ion recombination on the plasma production chamber wall should be lowered. The methods for production of ionizing electrons and for supply of materials to be ionized are also important. (author)