title: Deduction of edge electron density with multiply charged ions in ORNL volume-type electron cyclotron resonance ion source.
abstract: The electron densities in the argon plasmas of the ORNL 6 GHz electron cyclotron resonance (ECR) ion source with a flat central magnetic field have been deduced from the ion branches of the electric probe current-voltage curves measured in the edge region of the plasmas. To overcome the difficulties due to unknown velocities of multiply charged ions at the sheath edge, a modified generalized Bohm criterion for the ion sheath velocity is introduced and the mean velocity of all ionic charge states at the sheath edge is assumed to be equal to the sound velocity of the system of particles. The calculated electron densities and temperatures for different plasmas optimized for four charge state distributions are discussed.
authors.affiliation: Electric Probe Applications Laboratory, Hanyang University, Seoul, Republic of Korea.
authors.forename: H-J
authors.initials: HJ
authors.lastname: You
authors.forename: H-J
authors.initials: HJ
authors.lastname: Woo
authors.forename: K-S
authors.initials: KS
authors.lastname: Chung
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: F W
authors.initials: FW
authors.lastname: Meyer
authors.forename: T
authors.initials: T
authors.lastname: Lho
authors.forename: M-J
authors.initials: MJ
authors.lastname: Lee
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D017357:Cyclotrons / Q000295:instrumentation*; D004583:Electrons; D005740:Gases / Q000737:chemistry*; D006358:Hot Temperature; D007477:Ions; D008962:Models, Theoretical; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D055672:Static Electricity
chemical_list: D005740:Gases; D007477:Ions