Thick concrete walls will shield most radiation.
It's sort of a multi-step process, but the short answer is that physicists have 1) a catalog (so to speak) of known particles, including their mass, charge, lifetime, decay products and so on: 2) a catalog of particles that have NOT been seen before, and calculated values for their parameters For example, the discovery of the Omega- particle was a triumph for theoretical physics (Gell-Mann and Ne'eman independently predicted its existence). They predicted that there had to be a particle with spin 3/2 and charge -1 and "strangeness" value 3, based on the fact that there was a missing hadron in the particle zoo, and calculated its mass and decay products.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
Technetium is an artificial chemical element.Technetium is an artificial chemical element and is extracted from fission products, prepared by neutron activation or by irradiation in particles accelerators.
nuclear fission