Grossweiner [1] was the first to use the shape of the glow-peak to calculate the trap depth and the frequency factor. His method is based on the temperature at maximum and on the low temperature at half intensity, T ₁ . Using the first order-kinetics one can write

(1)

(2)

their ratio is

(3)

The integral in brackets can be resolved by asymptotic expansion as indicated before. By dropping terms after the first in the series, expression (3) changes in the following

(4)

Doing the logarithm and rearranging using the maximum condition one obtains

(5)

For E/kT larger than 20, the exponential of the last expression becomes equal to 0.184. Furthermore, the term ( T ₁/ T _M) ² may be neglected because it affects E by less than 2% if s/ ? is larger than 10 ⁷. These approximations get the final form

(6)

This expression was empirically modified by Chen [2] with 1.41 replacing 1.51 to get a better accuracy in the calculation of E, i.e.

(7)

The frequency factor can be directly obtained from the following expression

(8)