Formation of Ion Beam from High Density Plasma of ECR Discharge

Journal Article · Tue Mar 15 04:00:00 EST 2005 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.1893405· OSTI ID:20630675

Izotov, I; Razin, S; Sidorov, A; Skalyga, V; Zorin, V; Geller, R; Lamy, T; Sortais, P; Thuillier, T ^[1]

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1. Institute of Applied Physics, Nizhny Novgorod (Russian Federation)

One of the most promising directions of ECR multicharged ion sources evolution is related with increase in frequency of microwave pumping. During last years microwave generators of millimeter wave range - gyrotrons have been used more frequently. Creation of plasma with density 1013 cm-3 with medium charged ions and ion flux density through a plug of a magnetic trap along magnetic field lines on level of a few A/cm2 is possible under pumping by powerful millimeter wave radiation and quasigasdynamic (collisional) regime of plasma confinement in the magnetic trap. Such plasma has great prospects for application in plasma based ion implantation systems for processing of surfaces with complicated and petit relief. Use it for ion beam formation seams to be difficult because of too high ion current density. This paper continues investigations described elsewhere and shows possibility to arrange ion extraction in zone of plasma expansion from the magnetic trap along axis of system and magnetic field lines.Plasma was created at ECR gas discharge by means of millimeter wave radiation of a gyrotron with frequency 37.5 GHz, maximum power 100 kW, pulse duration 1.5 ms. Two and three electrode quasi-Pierce extraction systems were used for ion beam formation.It is demonstrated that there is no changes in ion charge state distribution along expansion routing of plasma under collisional confinement. Also ion flux density decreases with distance from plug of the trap, it allows to control extracting ion current density. Multicharged ion beam of Nitrogen with total current up to 2.5 mA at diameter of extracting hole 1 mm, that corresponds current density 320 mA/cm2, was obtained. Magnitude of total ion current was limited due to extracting voltage (60 kV). Under such conditions characteristic transversal dimension of plasma equaled 4 cm, magnetic field value in extracting zone was about 0.1 T at axisymmetrical configuration.

• OSTI ID: 20630675
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 749; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BEAM CURRENTS
BEAM EXTRACTION
CHARGE STATES
CURRENT DENSITY
ECR ION SOURCES
ELECTRON CYCLOTRON-RESONANCE
FLUX DENSITY
GHZ RANGE
ION BEAMS
ION IMPLANTATION
MAGNETIC FIELDS
MICROWAVE AMPLIFIERS
MULTICHARGED IONS
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA EXPANSION
PLASMA PRODUCTION
PUMPING
RF SYSTEMS
TRAPS