[ben_w]

As for how to make, here's my other comment deeper in the thread: https://news.ycombinator.com/item?id=37687741

As for how to detect:

When antiparticles contact matter particles, they annihilate, releasing the mass as energy.

For positrons and electrons, this is a nice simple process of "two photons with a combined energy of just over 1MeV" (in the collision frame of reference they are equal in energy, 511 keV, and going in opposite directions); for protons and antiprotons, each quark does its thing separately so you get a whole mess of other things that are themselves unstable and I don't know the characteristic signatures of, only that they have one and you can look for it.