In this paper, triple differential cross-sections for the ionization of metastable 2P-state hydrogen atoms by 250 eV electron energy with exchange effects for various kinematic conditions are calculated. Multiple scattering theory proposed by Das and Seal in {\it Phys. Rev.} A 47, 2978 (1993) is utilized here. The computational results provide significant peak features that show good qualitative agreement with the hydrogenic ground-state experimental data and theoretical results and the present first Born results. In addition, physical origin of the peaks of the cross-section curves is investigated.

In the present work, the triple-differential cross-sections (TDCSs) for the ionisation of metastable 3P-state hydrogen atoms at an incident electron energy of 250 eV with exchange effects are computed in the asymmetric coplanar geometry for various kinematic conditions. The final-state wave function of Das and Seal (Phys. Rev. A 47, 2978 (1993)) is used here. The results of the present calculation are compared with the available hydrogenic ground-state experimental data and other existing theoretical results. An analysis of the results reveals qualitative enhancement with other compared results. The implication of the present study offers an extensive scope for experimental verification in such a field of ionisation.