Thermally activated dislocation generation

Calculate the probability of a dislocation loop in aluminium being generated by thermal activation Assume that the minimum possible loop size is six Burgers vectors so that at least one atom is enclosed by the loop Calculate the probability at temperatures of 300 K and 900 K The shear modulus of aluminium is G = 26GPa, its Burgers vector is = 2.86 x 10 °m. 

---