Helix SFT: The Helium Instrument

The Thermo Scientific Helix SFT is an updated, upgraded version of the GVI instrument. The SFT is a magnetic sector mass spectrometer with a 120 ̊ flight tube with a 35cm radius of curvature. The split flight tube which gives rise to the name is an essential feature for precision measurement of ³He free from influence of ⁴He. The split in the flight tube reduces weight and volume of the flight tube, while an additional 90 ̊ 5cm radius spur with an energy filter helps reduce ⁴He influence on the comparably tiny ³He beam.