The electric field in an annular cathode area is modeled to investigate the electrical power deposition into plasma inside a small-bore cooper bromide laser tube. The electrical power deposition is determined for various strengths of magnetic fields applied in the axial direction. The deposited electrical power is considered comprise axial and radial parts. It is shown that, the electrical power deposited radialy into the plasma is decreased in the cathode area by increasing the strength of the magnetic field, and the magnetic field has no effect on the axial part. Moreover, the results of the theoretical model are discussed referring to the experimental observations.
