This chapter illustrates some examples of energies of helium (He) atoms in a metal lattice and cross-sections in different metals and Ni-isotopes as a function of neutron energy. Cross-sections σ for 14 MeV neutron-induced nuclear reactions generating He in different element, and cross-sections σ for He production in Ni, Mo and Al are plotted as a function of the neutron energy E. He concentration in Ni58 after irradiation with a neutron fluence at different positions in two typical mixed-spectrum reactors is illustrated. Cross sections σ for the production of He, Sc46, V48, Cr51, Co56, Co57, Co58, Mn52, Mn54, Zn65 by protons and deuterons, in different metals respectively are figured out. Projected range R, standard deviation of the ion distribution σ and number of Frenkel pairs per injected He4 atom in vanadium, aluminum, nickel, molybdenum, tungsten, silicon are graphically ilustrated as a function of injection energy E. Displacement rate and implantation rate as a function of depth x produced by bombarding nickel with α particles are figured out. Displacement damage (Frenkel pairs) per unit projected path length dN/dx in nickel for α-particles vs. distance from nucleus x with a starting energy of 1 and 5 MeV are illustrated. Examples for metal ion-metal ion, metal-metal, metal ion-He pair potential employed in atomistic computer simulations of the properties of He atoms in perfect and imperfect metal lattices are figured out. Comparison of desorption spectra of Mo and Ni are also illustrated.