The absolute threshold photodetachment cross-section of Al-

الملخص EN

The total absolute photodetachment cross-section of the aluminum anion, Al-, is calculated in the threshold spectral region for photons of wave numbers 3400 -3650cm-1 using the zero-core-contribution (ZCC) model.

A computer least-squares curve fit is used to test the validity of the Wigner threshold law and the deviation from recent experimental measurements of the relative photodetachment cross- section .

It is found that the best agreement is achieved with a smaller core radius r0 = 1.60? rather than the value of 1.82? used earlier.