// Scilab code Exa5.2 : : Page 203 (2011) // We have to make calculation for alpha particle and for proton clc; clear; E_a = 8.766; // Energy of the alpha particle, mega electron volts A_Bi = 209; // Atomic mass of Bi-209, atomic mass unit A_a = 4; // Atomic mass of alpha particle, atomic mass unit A_p = 1; // Atomic mass of proton, atomic mass unit e = 1.6e-019; // Charge of an electron, coulomb Z = 83; // Atomic number of bismuth R_0 = 1.4e-015; // Distance of closest approach,metre K = 8.99e+09; // Coulomb constant B_H_a = 2*Z*e^2*K/(R_0*1.6e-013*(A_Bi^(1/3)+A_a^(1/3))); // Barrier height for an alpha particle, mega electron volts B_H_p = 1*Z*e^2*K/(R_0*1.6e-013*(A_Bi^(1/3)+A_p^(1/3))); // Barrier height for proton, mega electron volts printf("\nBarrier height for the alpha particle = %5.2f MeV \nBarrier height for the proton = %5.2f MeV", B_H_a,B_H_p); // Result // Barrier height for the alpha particle = 22.67 MeV // Barrier height for the proton = 12.30 MeV