ABSTRACT
If r = 1 × 10-12 cm, Z = 85, then the magnitude of the barrier U ≈ 25 MeV is obtained. This value is much higher than ordinary α-particle energies of a few MeV. α-Particles cannot pass through the barrier from the classical viewpoint. The quantum theory for the tunnel effect settled the problem. The penetration rate P is given by
e ,
2 2 ( ( ) ) dP G m U r E rG
∫= = −− α (5.4) in which R and b are the radii, as shown in the ‚gure. The value of P is nonzero.
