Where does the emission of a radioactive material directed at?
My intuition and background knowledge would firmly say that it is pointing at all directions outward of the atomic nucleus. But let's say we have an atomic nucleus undergoing alpha decay at the origin $(0,0,0)$ in an imaginary cartesian plane, what would be the angle of one specific helium atom at time $t$? Are there any experimental procedures or computations that may resolve this?
I guess encasing the radioactive material inside a sphere that can detect emission would do the trick, but are there any hypothesis or background info to possible relations such that it would "favor" one direction to another?
Furthermore, is it possible to "stop" the emission at a given direction? Not necessarily blocking the material such that the emissions at that plane are absorbed but directing the nucleus to emit in a certain direction.