Ion‐surface interaction system (ISIS) for the study of redeposited materials: An application of decelerated ion beams with quartz‐crystal microbalances

• Published in: Review of scientific instruments 1990-08, Vol.61 (8), p.2184-2193
• Main Authors: Youchison, D. L., Nahemow, M. D.
• Format: Article
• Language: English
• Subjects: 656003 - Condensed Matter Physics- Interactions between Beams & Condensed Matter- (1987-); 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 700209 - Fusion Power Plant Technology- Component Development & Materials Testing; ACCELERATION; BALANCES; BEAMS; BINDING ENERGY; CLOSED PLASMA DEVICES; COATINGS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTAL STRUCTURE; DUOPLASMATRONS; ELECTRON TUBES; ENERGY; ENERGY BEAM DEPOSITION FILMS; ENERGY RANGE; Exact sciences and technology; ION BEAMS; ION SOURCES; KEV RANGE; KEV RANGE 10-100; LIMITERS; MEASURING INSTRUMENTS; MICROBALANCES; MICROSTRUCTURE; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; PLASMA ACCELERATION; PLASMATRONS; SPUTTERING; THERMONUCLEAR DEVICES; TOKAMAK DEVICES; WEIGHT INDICATORS
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.1141387

The ion‐surface interaction system (ISIS) is a facility developed for the study of redeposited fusion impurity control surfaces. It was designed to investigate variations in the sputtering yield and surface binding energy caused by alterations to the surface microstructure. ISIS can create redeposited films similar to that found on tokamak limiters continuously sputtering a target at incident energies representative of a tokamak edge plasma. A duoplasmatron ion source is used to produce well‐focused, mass‐analyzed 30‐keV particle beams of H+ to Xe+ with fluxes of 1E15 to 7E15 ions/cm2 s. These beams are decelerated to the 100–1000 eV range before target impact with currents from 50 to 900 μA. The sputtered neutrals are ionized, accelerated to the incident sputtering energy, and deposited onto another target substrate in a controlled background. The deposited film is then sputtered i n s i t u to determine changes in sputtering yield and surface binding energy. The sputtering and redeposition of the ionized sputtered particles is monitored via a unique dual quartz‐crystal‐microbalance apparatus. As many as eight samples are accommodated in this apparatus by a carousel arrangement that facilitates the redeposition while permitting the exchange of crystals (targets) under vacuum. Targets may be either bulk samples or films evaporated onto planar 4.4‐MHz AT‐cut quartz crystals. The system is complete with computerized data acquisition, residual gas analysis, and multiple current transducers.