Yet another forkload of techno-BS piled onto FR.
First, the unit is “gray” not “ray”, names after Henry Louis Gray. 10 gray, or 1000 RADs of radiation, is enough to destroy a person’s bone marrow, which would kill them within 30 days. A medical chest X-ray is about 7 miligray, or 0.007 grays, so the lethal radiation dose would be equivalent to the radiation emitted by about 1,429 chest X-rays at once.
To generate that kind of ionizing radiation power requires enormous input power - think about a 2000 watt battery these yahoos were planning to use - that’s a van load. A battery of that size might be able to produce enough energy for a lethal dose of X-rays over a period of several hours of exposure. And since X-ray radiation strength decreases the further it is from the source, they’d have to be very close to the target - or make up for the distance with even more power. What were they going to do, drive up beside the victims bedroom window as he slept? Also, power sources capable of generating this kind of power require cooling, which further adds bulk and reduces portability. They’d better get a full-size van - plus.
So, it an X-rry superweapon feasible? If you could entice your victim to sleep in an abandoned power substation or something - maybe. But there are far simpler and more effective ways to kill someone. And once again, we see the combined effect of lousy science education and lazy journalists.
OK, I'll tell my dentist she's using an xgray machine in her office......