Ok I understand that a hydrogen gas of non-ions at a temperature higher than its surroundings exists with many excited electrons. These electrons, either spontaneously or due to collisions, will return to a ground state and emit photons. Thus, the speed of the H atom will decrease and energy is transferred to the surrounding media.
But! What if I have a H+ gas (hydrogen ion gas)? Hypothetically lets say I have 10 H+ atoms, i.e. 10 protons. These protons are travelling at some high speed (v<< c) and thus have some high temperature.
Do these protons lose energy, are photons emitted? There are no electrons, so what mechanism causes them to lose energy?
If they can only lose energy via acceleration, does that mean a group of 10 protons will never lose energy (never cool down) since the mean free path is enormous and thus never accelerate?