[xt00]

What’s the difference between photons coming off the gold ion traveling at 0.995c vs a high energy photon with a high frequency like a gamma ray? Like can’t you shoot 2 beams of gamma rays at each other and have matter anti matter pairs pop up?

[jlokier]

The difference is you effectively control the path of the photons coming off the gold ion due to that 0.995c and the ion itself being in a focused beam which depends on its charge. The photon is projected forward in the direction of travel.

Gamma beams are hard to come by. How are you going to make two focused, directional gamma beams pointing accurately at each other?