This focused the rays of a specific mass-to-charge ratio through a narrow slit. These were then detected in real time using an electrometer, doing away with the cumbersome photographic plates.

The Large Hadron Collider (LHC) gets a breath of fresh air as it collides beams of protons and oxygen ions for the very first time. Oxygen–oxygen and neon–neon collisions are also on the menu ...

A 16-parts-per-trillion measurement of the antiproton-to-proton charge–mass ratio. Nature . Published online January 5, 2022. doi: 10.1038/s41586-021-04203-w.

An ultrasensitive experiment comparing protons with their antimatter counterparts found no difference in the ratios of their charge to mass, researchers report in the Aug. 13 Nature.

Sunday Times News: The atomic mass of a specific atom or molecule is determined by using an experimental technique called mass spectrometry.

For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass, it seemed that something besides the protons in the nucleus ...

"This rare isotope, which is lighter than the more common 4 He by just one neutron, is scarce in our solar system — found at a ratio of about one 3 He ion per 2,500 4 He ions," Radoslav Bucik ...