Normal cathode fall Vn, reduced normal current density jn/p2 (p denotes pressure), and reduced position of negative glow dgp (dg is defined as a distance between the cathode surface and the brightest position in the negative glow) of a cold barium cathode in rare gases were measured. For He, Ne, Ar, Kr, and Xe, Vn=81, 82, 82, 73, and 71 V, jn/p2 =3.7, 3.0, 42, 41, and 37 μA cm−2 Torr−2, and dgp=0.75, 0.51, 0.21, 0.12, and 0.16 cm Torr, respectively. The operating voltage of the Ba cathode in 20 Torr Xe showed no change after 10 000-h dc operation, and there was no observable chemical interaction between the barium and Zn2SiO4:Mn phosphor. Barium cathodes were formed in an 8-in. diagonal gas-discharge panel for TV display by thermally dissociating Ba(N3)2: the operating voltage was 1/2, and the power consumption and required cathode area were 1/4 of the same parameters for a similar panel with a Ni cathode.