## 1 Introduction  
The bremsstrahlung processes [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12] in thermal and nonthermal plasmas have received considerable attention in astrophysics and plasma physics since the continuum X-ray spectra due to the electron-nucleus and electron-atom bremsstrahlung processes have long been used for plasma diagnostics in various weakly coupled astrophysical plasmas. Most research papers have considered the bremsstrahlung process for the electron-ion collision rather than for the electron-atom process, because of the smaller population of neutral atoms in highly ionized plasmas. Especially the electron-nucleus bremsstrahlung cross section [13] in weakly coupled plasmas has been extensively investigated by using the Yukawa-type Debye-Huckel potential. The electron-atom bremsstrahlung process [9; 14; 15] is quite important in weakly ionized plasmas, i.e., where the scattering of electrons by neutral atoms is important. In the electron-atom bremsstrahlung or scattering case, the screening [1; 9] by the bound atomic electrons plays a crucial role in the cross section and the spectrum of the bremsstrahlung process. The influence of atomic screening on the electron-atom bremsstrahlung cross section can be studied with the Thomas-Fermi statistical model [16] for many-electron atoms. In addition, the doubly differential electron-atom bremsstrahlung cross section with form factor based on the approximate self-consistent Dirac-Hartree-Fock-Slater calculations has been obtained at high energies [15]. It is obvious that the Coulomb focusing factor for the electron-ion bremsstrahlung process is not the same with the electron-atom bremsstrahlung process because the effective charge of the bound atomic electrons is different from the total charge of the nucleus. However, the influence of Coulomb focusing on the electron-atom bremsstrahlung cross section and the radiation spectrum has not been investigatedyet. In many plasmas, the coupling of the thermal plasma with the external radiation field produces the nonthermal plasma whose distribution is quite different from that of a Maxwellian plasma [17; 18]. It has also been shown that the plasma electrons that deviated from the Maxwellian distribution are well represented by the Lorentzian distribution since the interaction potential in nonthermal plasmas cannot be appropriately obtained by using the conventional Debye-Huckel potential [18; 19; 20; 21]. Therefore, we are motivated to study the bremsstrahlung process for electron-atom collision under the influence of atomic screening and Coulomb focusing correction in nonthermal plasmas. In this work, we derive the bremsstrahlung cross section for the electron-atom system by employing the Thomas-Fermi method with the effective charge of the atom. The Coulomb focusing correction for the electron-atom bremsstrahlung cross section near the threshold domain is also obtained by the modified Elwert-Sommerfeld factor with the mean effective charge for the electron-atom interaction based on the Thomas-Fermi solution. In addition, we obtain the Coulomb focused bremsstrahlung emission rates by encounters of nonthermal electrons and neutral atoms such as Fe (iron) and W (tungsten) atoms. This paper is composed as follows: in Section 2, we introduce the Thomas-Fermi model for atoms and discuss the solution of the Thomas-Fermi model. We also obtain the mean effective charge based on the Thomas-Fermi method. In Section 3, we discuss the nonrelativistic electron-atom bremsstrahlung process and the Elwert-Sommerfeld Coulomb focusing factor. In Section 4, we obtain the modified electron-atom bremsstrahlung cross section by using the Thomas-Fermi solution including the Coulomb focusing factor with the mean effective charge of many-electron atoms. In Section 5, we obtain the closed form of the bremsstrahlung emission rates in nonthermal plasmas using the Lorentzian distribution function.