Direkt zum Inhalt springen
Deutsch English
The Neutron Source
News and Events
User Office




No events found.


No events found.


Hydrogen in heme enzymes - catching the wave
November 03 14:30 - 15:30

Heme-containing enzymes have evolved to utilise the intrinsic oxidizing power of dioxygen, notably...
In-plane anisotropic spin excitations in the tetragonal phase of iron-pnictide superconductors
November 10 14:30 - 15:30

Generally, electronic response in the normal state of metals adopts a symmetry of their crystal...
The mobility of vacancies and hydrogen in thin-film hydrogenated amorphous silicon solar cell layers during annealing
November 17 14:30 - 15:30

In this presentation, our recent studies on hydrogenated amorphous silicon (a-Si:H) solar cell...
more Events ->

What is a neutron?

animation neutronenzerfall neu
Free neutrons decay by emission of an electron and an electron antineutrino to become a proton after 14,8 minutes.

Neutrons are within nuclei of atoms. They belong to the group of the fundamental particles, the smallest known composites of the matter. They do not possess any electric charge, they are neutral. That is where the name neutrons comes from, which was invented by their discoverer James Chadwick (Discovery of the neutrons). The neutron's spin is ½, their mass 1,67 * 10-24 gramms. Free neutrons being outside of the nucleus can live for 886 seconds, almost 15 minutes - this is quite long for a fundamental particle. Then they decay by emission of an electron and an electron antineutrino to become a proton.

Free neutrons interact with fundamental particles within the nucleus, if they hit an atom. Thus, their effect on the atom depends on the number of neutrons and protons within the nucleus. Nuclei with a certain number of neutrons and protons are called nuclide. Nuclides with the same number of protons, but a different number of neutrons, are called isotopes (of an element). The interaction of X-rays with matter depends on the electrons of an atom and therefore all isotopes of an element interact the same way. But free neutrons interact with the particles within the nucleus causing different interactions for different isotopes of the same element (Why neutrons?).