Helix SFT

High-resolution static vacuum mass spectrometer (SVMS) for precise noble gas isotopic analysis. Specially designed for the simultaneous analysis of helium isotopes, with advanced dual-focusing ion optics and a 35 cm, 120° magnetic sector analyzer.

• Status: Active
• Country: Germany
• Isotopic: Yes
• Type of measurable elements: Noble gases
• Measurable isotopes/elements: Isotopes of noble gases
• Analyzer type : Magnetic Sector MS
• Ion source type: Electron impact
• Inlet types: Dual inlet with getter pumps, pipettes, and cold traps
• Mass range : 1-140 Daltons
• High Resolution : Yes
• Mass resolution/ Mass resolving power : Faraday detector: >400; Multiplier detector: >700
• Multicollector : Yes
• Collectors qty : 5 Faraday detectors for high mass spur and SEV217 electron multiplier for low mass spur
• Sensitivity : Helium: >2×10−4 Amps/Torr; Argon: >1×10−3 Amps/Torr
• Abundance sensitivity : <1 ppb for adjacent masses (3 contribution from 4) at a pressure of 1 x 10-7 mbar
• Dynamic range : 1 cps to ~1.4 × 10⁶ cps
• Detection limits : Sub-ppb levels for noble gases
• Signal stability, relative standard deviation : <0.2% drift per hour at 300 kcps; Drift to be less than the equivalent of +/- 50 ppm in mass over 30 minutes at mass 40
• Detector type : Faraday detectors and SEV217 discrete dynode electron multiplier
• Possible amplifiers : 10¹⁰, 10¹¹, 10¹², and 10¹³ Ω resistors
• Acceleration voltage : 4.5 kV
• Background : Dark noise: <10 cpm (0.2 cpm typical)
• Geometry type : Extended geometry with 120° deflection
• Focusing type : Single focusing
• Magnetic sector radius/ angle : 35 cm radius; 120° deflection
• Cooling system : Liquid nitrogen cooling for getter pumps; water cooling for turbo pumps
• Vacuum system : Ultra-high vacuum with 40 L/s ion pump, 70 L/s turbo molecular pump, and non-evaporable getter pump
• Gas supply: High-purity noble gases (e.g., helium, neon, argon)