Skip to content

objectives

OBJECTIVE_NAMES = {1: 'Plasma major radius', 3: 'neutron wall load', 4: 'total TF + PF coil power', 5: 'ratio fusion power:injection power', 6: 'cost of electricity', 7: 'constructed cost', 8: 'aspect ratio', 9: 'divertor heat load', 10: 'toroidal field on axis', 11: 'injection power', 14: 'pulse length', 15: 'plant availability factor', 16: 'Major radius/burn time', 17: 'net electrical output', 18: 'NULL', 19: 'Major radius/burn time'} module-attribute

objective_function(minmax)

Calculate the specified objective function

Parameters:

Name Type Description Default
minimax int

the ID and sign of the figure of merit to evaluate. A negative value indicates maximisation. A positive value indicates minimisation. * 1: Major radius * 3: Neutron wall load * 4: TF coil + PF coil power * 5: Fusion gain * 6: Cost of electricity * 7: Direct/constructed/capital cost * 8: Aspect ratio * 9: Divertor heat load * 10: Toroidal field on axis * 11: Injected power * 14: Pulse length * 15: Plant availability * 16: Major radius/burn time * 17: Net electrical output * 18: NULL, f(x) = 1 * 19: Major radius/burn time

 required
Source code in process/core/solver/objectives.py 
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
def objective_function(minmax: int) -> float:
    """Calculate the specified objective function

    Parameters
    ----------
    minimax : int
        the ID and sign of the figure of merit to evaluate.
        A negative value indicates maximisation.
        A positive value indicates minimisation.
        * 1: Major radius
        * 3: Neutron wall load
        * 4: TF coil + PF coil power
        * 5: Fusion gain
        * 6: Cost of electricity
        * 7: Direct/constructed/capital cost
        * 8: Aspect ratio
        * 9: Divertor heat load
        * 10: Toroidal field on axis
        * 11: Injected power
        * 14: Pulse length
        * 15: Plant availability
        * 16: Major radius/burn time
        * 17: Net electrical output
        * 18: NULL, f(x) = 1
        * 19: Major radius/burn time
    """
    figure_of_merit = abs(minmax)

    # -1 = maximise
    # +1 = minimise
    objective_sign = np.sign(minmax)

    match figure_of_merit:
        case 1:
            objective_metric = 0.2 * physics_variables.rmajor
        case 3:
            objective_metric = physics_variables.pflux_fw_neutron_mw
        case 4:
            objective_metric = (
                tfcoil_variables.tfcmw + 1e-3 * pf_power_variables.srcktpm
            ) / 10.0
        case 5:
            objective_metric = physics_variables.p_fusion_total_mw / (
                current_drive_variables.p_hcd_injected_total_mw
                + current_drive_variables.p_beam_orbit_loss_mw
                + physics_variables.p_plasma_ohmic_mw
            )
        case 6:
            objective_metric = cost_variables.coe / 100.0
        case 7:
            objective_metric = (
                cost_variables.cdirt / 1.0e3
                if cost_variables.ireactor == 0
                else cost_variables.concost / 1.0e4
            )
        case 8:
            objective_metric = physics_variables.aspect
        case 9:
            objective_metric = divertor_variables.pflux_div_heat_load_mw
        case 10:
            objective_metric = physics_variables.b_plasma_toroidal_on_axis
        case 11:
            objective_metric = current_drive_variables.p_hcd_injected_total_mw
        case 14:
            objective_metric = times_variables.t_plant_pulse_burn / 2.0e4
        case 15:
            if cost_variables.i_plant_availability != 1:
                raise ProcessValueError("minmax=15 requires i_plant_availability=1")
            objective_metric = cost_variables.f_t_plant_available
        case 16:
            objective_metric = 0.95 * (physics_variables.rmajor / 9.0) - 0.05 * (
                times_variables.t_plant_pulse_burn / 7200.0
            )
        case 17:
            objective_metric = heat_transport_variables.p_plant_electric_net_mw / 500.0
        case 18:
            objective_metric = 1.0
        case 19:
            objective_metric = -0.5 * (
                current_drive_variables.big_q_plasma / 20.0
            ) - 0.5 * (times_variables.t_plant_pulse_burn / 7200.0)

    return objective_sign * objective_metric