Optimal and isodual ternary cyclic codes of rate 1/2

This work is twofold. First, the largest minimum distance of a ternary cyclic codes of parameters ${[n, \frac{n}{2}]}$ , is determined for n even, not a multiple of 3, by using the Chen algorithm, for n = 26, 34, 38, 46, 50, 58, 62, 68, 70, 74. Next, seven new classes of isodual ternary cyclic codes are introduced for n singly even, not a multiple of 3.