Mass Measurements with a Magnetic Time-of-Flight Mass Spectrometer

A new mass spectrometer has been used to measure the time of flight of ions for a number of complete revolutions in a magnetic field. This spectrometer is especially suitable for heavy masses; the following results have been obtained so far: Element Mass S³² 31.983 ±0.001 Cl³⁵ 34.9805 ±0.0005 K⁴¹ 40.975 ±0.002 Br⁷⁹ 78.944 ±0.001 Br⁸¹ 80.943 ±0.001 Kr⁸⁴ 83.938 ±0.001 Rb⁸⁵ 84.931 ±0.0015 Element Mass Rb⁸⁷ 86.9295 ±0.0020 I¹²⁷ 126.9415 ±0.0025 Xe¹²⁹ 128.9455 ±0.0015 Xe¹³⁰ 129.945 ±0.002 Xe¹³¹ 130.944 ±0.002 Xe¹³² 131.945 ±0.002 Xe¹³⁴ 133.947 ±0.002

The precision as tabulated is estimated from the consistency between independent runs. The "probable error" is about three times smaller.