In Neu Theory, an acronym for “neutron equivalent unit.” A neu is an absolute system of measurement by which a specific physical value is compared to the neutron physical quantity set at unity. Examples:
- mass: the measured 1.674 929 351 x 10-27 kg mass of the neutron is set equal to one atomic mass unit or a neumass of 1.000000.
- magnetism: the measured -0.966 236 47 x 10-26 J T-1 magnetic dipole of the neutron is set equal to -1.000 magneton.
The neu is slightly larger than the C12 amu representing an increase in relative mass value of approximately 0.8665 %. The atomic masses of the isotopes in the Neumass & Charge Radius Table are then compared to the neu unit quantity with a corresponding decrease in relative mass value of approximately 0.8595 % as compared to the C12 value. The absolute neu value of C12 becomes 11.896 914 249 instead of 12.000 000 000. Column I in the table provides the relative C12 values as published by the National Institute of Science and Technology (updated September 21, 2016), Column J provides the equivalent calculated absolute neu mass value of selected isotopes.
It should be clearly emphasized that the actual measured mass of atoms in kilograms and the equivalent energy value in joules, electron volts, or any other unit, is not changed in the slightest by using a neutron amu. The numerically smaller quantum neu mass value of an isotope is exactly balanced by the numerically larger quantum neu mass unit giving us precisely the same quantity of mass expressed in kilograms, that we had before.
The reason an absolute neu can be useful, is that it allows mass and energy to be counted with the same numeric scale, and allows us in principle to estimate the ratio of matter to energy in the cosmos.
The neu values of atomic nuclei are provided in the Neumass & Charge Radius Table.
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