  The influence of nitrogen impurities on the parameters of the self-sustained
normal dc glow discharge at atmospheric pressure was studied. The
concentrations of the low-excited helium atoms in states 2_1s, 2_1p, 2_3s and
2_3p were determined in the atmospheric pressure glow discharge in helium
(99.98%He) and in helium with a nitrogen admixture. It was shown that the
adding of nitrogen into helium (less 5%) leads to the increase of both
interelectrode gap voltage and gas temperature. At the same time the
drastically reduction of concentration of the low-excited helium atoms in
cathode region even at nitrogen admixture of 0.5 % is occurred.
