Artrons are the particle forms of released energies due to four-dimensional stresses. The TARDIS is in its most dormant state, and its most basic defense mechanism is to basically stretch and snap spacetime and let the shockwaves sort everything out. It's crude, but it's better than letting the wrong people get their hands, claws, tentacles, or force manipulators on it.

That being said, the artron blast will be a lightspeed-fast shockwave that emanates out with the TARDIS at the epicenter, temporally scrambling the landscape and everyone in it into one big anachronistic mess. Barren rock reaches, primordial seas, and dinosaur-infested jungles will show right next to abandoned futuristic glass cities of TEH FUTUR. Players can have fun coming up with ancient versions of their own canon's critters.