Influence of electron capture and Coulomb explosion on electron screening in low energy nuclear reactions in laboratories

We discuss the effects of electron capture by the projectile and the Coulomb explosion of a molecular projectile on the electron screening in low energy nuclear reactions in laboratory. Using the idea of equilibrium charge, we show that the electron capture of projectile leads to a screening energy which significantly exceeds the adiabatic limit in the simple consideration for the D(d,p)T reaction and provides a possibility to explain the large screening energy claimed in the analysis of experimental data. We then show that the Coulomb explosion can result in a large apparent screening energy as large as that encountered in the analysis of ^3He(d,p)^4He reactions induced by the molecular D_2^+ and D_3^+ projectiles at very low energies.