On boundaries of ping-pong modes in multipacting.

Multipactor is an avalanche multiplication of the number of electrons in radio-frequency devices due to secondary electron emission. One of the possible modes of this kind of discharge was studied in detail and was named “a ping-pong mode” in a publication by R. A. Kishek [Phys. Rev. Lett. <bold>108</bold>, 035003 (2012) and Phys. Plasmas <bold>20</bold>, 056702 (2013)]. In the present paper, I show that conditions of stability and cutoff limits are quite different from those derived in the cited papers. [ABSTRACT FROM AUTHOR]