calculate transport matrix

        :param gamma: electron energy measured by mc^2
        :return: transport matrix
        :rtype: numpy array

def calcTransM(self, gamma=None, type='simu'):
        """calculate transport matrix

        :param gamma: electron energy measured by mc^2
        :return: transport matrix
        :rtype: numpy array
        """
        sconf = self.getConfig(type=type)
        l = float(sconf['l'])
        k1 = self.getK1(type='ctrl')
        self.transM = mathutils.transQuad(l, k1, gamma)
        self.transM_flag = True
        return self.transM