A compact, resonant cavity, five centimeter, multicusp, ECR broad-beam ion source

Conference · Mon Jan 01 04:00:00 EST 1990 · Review of Scientific Instruments; (USA)

OSTI ID:6996962

Mahoney, L; Asmussen, J ^[1]

---

1. Michigan State University, East Lansing, Michigan 48824-1226 (US)

Researchers in many industrial and scientific activities desire a physically compact, long-life ion source that can produce high-current density broad-beams in chemically reactive gases such as CF{sub 4} and O{sub 2}. Earlier studies of a multicusp-ECR microwave-cavity ion source concept have demonstrated that a 5-cm-diam discharge can produce high beam current densities for broad-beam applications. More recently, this ion source concept has been redesigned to compact its size and to improve its operation and lifetime. In particular the physical size of the cylindrical microwave-cavity has been reduced to an outer diameter of 3.75 in. and an inner diameter of 3.5 in. Improved water and air cooling and permanent magnet arrangement allows the instrument to be operated continuously with powers greater than 200 W. The microwave cavity operates in the TE{sub 111} mode at 2.45 GHz and is self-starting in Ar, O{sub 2}, and N{sub 2} gases at discharge pressures necessary for beam extraction ({lt}5 mTorr). Ion densities of 10{sup 11}/cm{sup 3}--10{sup 12}/cm{sup 3} have been achieved with input powers less than 200 W. These ion densities produce ion current densities in excess of 10 mA/cm{sup 2} which may be extracted by either single- or multiple-grid extraction optics. The operation, diagnostics and performance of this new ion source is reviewed.

• OSTI ID: 6996962
• Report Number(s): CONF-890703--
• Conference Information: Journal Name: Review of Scientific Instruments; (USA) Journal Volume: 61:1
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular & Chemical Physics-- Beams & their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM CURRENTS
BEAM EXTRACTION
BEAMS
CAVITIES
CHEMICAL REACTIONS
COOLING
CURRENTS
CYCLOTRON RESONANCE
DESIGN
ELECTRON CYCLOTRON-RESONANCE
FLUID FLOW
FLUIDS
GAS FLOW
GASES
ION BEAMS
ION SOURCES
MAGNETS
OPERATION
PERFORMANCE
PERMANENT MAGNETS
POWER
RESONANCE
SIZE