⁴He-Helium 4

4He has 2 protons and 2 neutrons.
4He is a stable isotope.
The mass excess of 4He is 2424.91587 with an uncertainty of ±0.00015.


The mass was measured using a Penning Trap and the related equations include:

 Influence			 Equations

  100%				4He3-C 1  








Reference

1. R.S Van Dyck, Jr., D.L. Farnham, and P.B. Schwinberg (1993), Tritium–helium-3 mass difference using the Penning trap mass spectroscopy Physical Review Letters 
	70(19)
	https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.70.2888