I'm trying to understand what would really happen when large quantities (e.g., 10g) of anti-matter collide with matter. The normal response is that they'd annihilate each other and generate an expanding sphere of gamma ray photons.
However, thinking about it in more detail, what I see is that the anti-electrons annihilate first against the electrons. Let's assume the energy release in that case is not sufficient to noticeably change the momentum of the projectile. Then the nuclei penetrate the electron-annihilation plasma, and since antiprotons attract protons, their trajectory is changed. However, the nuclei are so small and so widely separated that presumably they just orbit each other as the electron clouds annihilate, and eventually enough energy is generated that the ionic plasma of nuclei and anti-nuclei just expands, with a small fraction of them actually ever combining.
In other words, we don't actually see total conversion happening -- only a small fraction of the total mass in an anti-matter/matter collision is turned into gamma rays.
Is that what actually would happen? (The ideal answer would be a video!)