Self-consistent structure of a dc discharge with a closed hall current in crossed electric and magnetic fields

A dc glow discharge with a closed Hall current in crossed electric and magnetic fields in helium is investigated. It is shown that the main features of an unmagnetized dc discharge [1] (such as the separation of the discharge into a space charge sheath and a quasineutral plasma, the formation of a cathode fall region and a negative glow, the appearance of a region with a reversed electric field producing a potential well for low-energy electrons and resulting in the formation of a Faraday dark space, and the formation of three pronounced groups of electrons in the electron distribution function) are also retained in a discharge in crossed fields. It is found that the sheath length is almost independent of the magnetic field, while the length of the negative glow region decreases appreciably with increasing magnetic field. The measured electron distribution function agrees well with the nonlocal theory, according to which the current in the Faraday dark space is carried by the intermediate electrons that are not trapped in the potential well and the energies of which are lower than the first excitation energy.