def cryostat_losses(Acr, dT=228.0):
    """
    Calculating the cryostat losses according to doi: 10.1088/1742-6596/97/1/012318
    :param Acr: the surface of the cryostat # m2
    :param dT: temperature difference between the maximum outside temperature (40C) and the working temp
    :return: losses of the cryostat
    """

    k_th = 2.0 * 1e-3  # W/(mK)
    d_th = 50.0 * 1e-3  # mm - thermal insulation thickness
    # the windings considered to work at 65 K -> dT = 293 - 65 = 228
    return round(k_th / d_th * Acr * 1e-6 * dT, 2)