• spontaneous emission error design;
  • extremal;
  • ternary self-dual code;
  • mutually disjoint 5-designMathematical Subject Classification: 05B05;
  • 94B05

It is known that extremal ternary self-dual codes of length inline image mod 12) yield 5-designs. Previously, mutually disjoint 5-designs were constructed by using single known generator matrix of bordered double circulant ternary self-dual codes (see [1, 2]). In this paper, a number of generator matrices of bordered double circulant extremal ternary self-dual codes are searched with the aid of computer. Using these codes we give many mutually disjoint 5-designs. As a consequence, a list of 5-spontaneous emission error designs are obtained.