Fusor Forums

Hi guys,

So can someone explain to me why neutrons are often classified by temperature whereas protons and electrons are not (not that I've heard of at least)?

Is it because the energy distribution of neutron resembles that of a noble gas whereas protons and electrons do not (because of their stronger interactions)?

Thanks,
Hunter Long

Not sure what you mean since I have never seen temperature really used to qualify the energy of a neutron. While the term "thermal" is used for a class of neutron energies (under some arbitrarily defined number in eV), eV is still the unit used to define any such energy; for instance, a 'room temperature' or thermal neutron could have an energy like 0.003 eV but rarely would anyone specify what that is in Kelvin. In fact, temperature has little real meaning for elementary particles (yes, sloppy use allows one to calculate such a meaningless value). Atoms do have temperature defined, but doing the math using a know energy for a neutron does not define a true temperature in a thermodynamic sense of the meaning.

Ok, thanks for the reply. So are there such a thing as "thermal" protons or electrons?

https://en.wikipedia.org/wiki/Neutron_temperature

If it is real and moves someone can clam it has an equivalent temperature. All of this ridiculous temperature bit has been dealt with in the FAQs here There are several related to this issue. Read the FAQs and learn!
Oddly, the critical FAQ and subsequent discussions are in this very forum......... Amazing!

Richard Hull

The reason it gets referred to so often for neutrons versus anything else is because reaction cross sections vary significantly for neutron especially when comparing fast to thermalized. Neutron cross sections have been hugely important going back the Manhattan Project and then reactor design. The same importance to science and industry is not as entrenched in studies of other particles.

Hunter is new here
maybe this should have been asked in the "New User Chat Area"