Abstract
It has been well known that a cathode made of LaB6 adsorbs xenon in a DC-type PDP and that a composite cathode made of LaB6 and BaAl2O4 adsorbs xenon and krypton. The work described in this report investigared this adsorption through the optical emission spectrum and its intensities, before and after aging test of cathodes, where the cathode surfaces were analyzed by XMA method. Coating materials composed of BaAl2O4 and conductive ceramics such as LaB6, GdB6, NdB6, WB, and MoB were tested, and each coating material was deposited on the cathode surface by using a plasma-spray technique. The plasma gases tested were He-Ar-Ne gas mixtures with a small amount of xenon or krypton or both. From the distribution pattern of x-ray images, the xenon ad krypton distributions overlapped the lantanum distribution but did not overlap the distributions of barium, aluminum, or the other elements of the cathodes. We therefore concluded that xenon and krypton ions trapped by the cathode are bounded and stabilized by a LaB6 crystal. The results also showed that GdB6 adsorbed xenon slowly and that NdB6 and MoB did not adsorb xenon or krypton at all.
