We prove that 23, 11, and 7 do not divide the order of the automorphism group of a binary [96, 48, 20] doubly-even self-dual code. We construct 25 new inequivalent binary [96, 48, 16] doubly-even self-dual codes via an automorphism of order 23.
Self-orthogonal ternary codes of minimum weight 3 may be analyzed in a straightforward manner using the theory of glueing introduced in earlier papers. The present paper describes a method for studying codes of minimum weight 6 : the supports of the words of weight 6 form what is called a center set. Associated with each center set is a graph, and all the graphs that can arise in this way are known. These techniques are used to classify the ternary self-dual codes of length 20 : there are 24 inequivalent codes, 17 of which are indecomposable. Six of the codes have minimum weight 6 .
On the basis of the results of X-ray photoelectron spectroscopy, theoretical analyses, and numerical simulations, the failure mechanism of an S-band pillbox output window applied in a high-average-power klystron is discussed. The influence of the high-order cylindrical-guide modes on the microwave power loss, the direction of the power flow and the window disk cracking are investigated. The high-order cylindrical-guide TM11 mode existing on the surface of the window ceramic disk may cause the carbon film deposition and excessive radio frequency losses on the disk and lead to the breakdown of the window.