Is question can be considered as an extension of the interaction between photon and atomic electron, where the energy level of atomic electron is elevated when absorbing photons and the process is reversible.

How would photons interact with:

  • Atomic nuclei
  • Neutron star surface
  • Degenerate neutron block

EDIT: interact means what happens when the photons collide with those objects. I don't believe that those object can exert any significant effect on photons at a distance. As a comparison, when photon "collide" with an atomic electron cloud, the electron's energy level become elevated.


closed as too broad by ACuriousMind, John Rennie, Kyle Kanos, user36790, Gert Mar 31 '16 at 1:36

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ What do you mean "how"? What exactly do you want to know? Be specific! $\endgroup$ – ACuriousMind Mar 29 '16 at 19:28
  • 2
    $\begingroup$ Well, atomic nuclei have excited states, many of which relax through gamma emission. Conversely, they will happily absorb a photon of the right energy to go up to the excited state. $\endgroup$ – Jon Custer Mar 29 '16 at 19:51
  • $\begingroup$ This seems to be a fairly broad question. $\endgroup$ – Kyle Kanos Mar 30 '16 at 10:15

One kind of nuclear response to a photon happens at very high photon energies (like, gamma rays up to thousand-kilovolts range, an order of magnitude beyond X-rays). That is the energy requirement to excite a nucleus above its ground state (you wouldn't want to be in the room when that is happening).

The only useful exception, is if an excited nucleus (made in nuclear decay) were to generate a gamma, that hits a matching unexcited nucleus, there's a good chance of absorption of the photon, if the energy match is VERY exact. This is the Mossbauer effect, and the energy match requirement is extremely useful.

The other response is magnetic spin interaction. NMR (nuclear magnetic resonance) is the kind of nuclear response to photons we can observe at modest photon energies. Some (H_1 yes, He_4 no) nuclei are magnetic, can be aligned (using a strong magnetic field) after which that alignment can be made to oscillate in an applied (radio frequency) field. It only takes enough photon energy to compete with the magnetic field alignment, the 'spin lattice', not enough to change the internal nuclear binding energy. So, it's OK to be in the room when it's happening.


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