introduction: occupational exposure to ionizing radiation due to medical activities (both diagnostic and therapeutic procedures) has increased sharply in recent years. among the occupationally exposed workers in these fields, those most affected by this increased exposure to ionizing radiation are nuclear medicine workers. in this study, annual average effective dose, annual collective effectiv...

background: annual patient effective dose equivalent can be considered as a quantitative physical parameter describing the activities performed in each nuclear medicine department. annual staff dose equivalent could be also considered as a parameter describing the amount of radiation risk for performing the activities. we calculated the staff to patient dose equivalent ratio to be used as a phy...

A variational method for calculating the critical nuclear charge ZC required for the binding of a nucleus to two electrons is reported. The method is very effective and performs well compared to the traditional variational principle for calculating energy. The critical nuclear charge, which corresponds to the minimum charge required for the atomic system to have at least one bound state, has be...

Effective nuclear charge, the charge an electron experiences after accounting for the shielding due to other electrons, increases from left to right across a given period, thus an electron in a 2p orbital of a nitrogen atom experiences a greater Zeff (3.83) than an electron in a 2p orbital of a carbon atom (3.14). This trend makes sense if we consider what happens to atomic structure as we move...

The self-energy screening correction is evaluated in a model in which the effect of the screening electron is represented as a first-order perturbation of the self energy by an effective potential. The effective potential is the Coulomb potential of the spherically averaged charge density of the screening electron. We evaluate the energy shift due to a 1s1/2, 2s1/2, 2p1/2, or 2p3/2 electron scr...