Hello all, I run a campaign in my own universe where such a piece of equipment exists, however I wanted to share it with you all in case anyone wanted to use it. I would first like to give credit to palladium games "rift" for the inspiration. The high-velocity-planetary particle shield (henceforth referred to as HVPPS) is a large form of specialized particle accelerator built into a large asteroid, planetoid or capital ship. The device accelerates several particles at a time (more as it gets larger) not for the purpose of smashing them, but to shot them into the orbit of a nearby planet at near-C velocities so that, if enough of them are in orbit, any ship/object traveling through the "shield" will be hit by several particles that smash right through the hull causing a catastrophic failure of structural integrity and therefor causing the ship to at least lose cabin pressure, or if the belt is big enough be disintegrated entirely. Such a device would obviously be made illegal by any sovereign state with a law level above 1, and would require software that is incredibly advanced giving it a Tech. level of at least 10, or more likely 11. At least 20 such particles must be put into orbit, with the strength of the shield increasing with the number of particles. The particles fired from a HVPPS would theoretically remain effective for 10-20 thousand years, however hastily run calculations, repeated use of the particles and other upsets can reduce it down to as little as 15 years.