vacuum_variables

i_vacuum_pumping = None module-attribute

switch for vacuum pumping model:

• ='old' for old detailed ETR model
• ='simple' for simple steady-state model with comparison to ITER cryopumps !#TODO: old and simple not suitable names.

n_iter_vacuum_pumps = None module-attribute

number of high vacuum pumps (real number), each with the throughput of one ITER cryopump (50 Pa m3 s-1), all operating at the same time (i_vacuum_pumping='simple')

i_vacuum_pump_type = None module-attribute

switch for vacuum pump type:

• =0 - for turbomolecular pump (magnetic bearing) with speed of 2.0 m3/s (1.95 for N2, 1.8 for He, 1.8 for DT)
• =1 - for compound cryopump with nominal speed of 10.0 m3/s (9.0 for N2, 5.0 for He and 25.0 for DT)

n_vv_vacuum_ducts = None module-attribute

number of ducts (torus to pumps)

dlscal = None module-attribute

vacuum system duct length scaling

pres_vv_chamber_base = None module-attribute

base pressure during dwell before gas pre-fill(Pa)

pres_div_chamber_burn = None module-attribute

divertor chamber pressure during burn (Pa)

molflow_vac_pumps = None module-attribute

Pump throughput (molecules/s) (default is ITER value)

outgrat_fw = None module-attribute

plasma chamber wall outgassing rate (Pa-m/s)

temp_vv_chamber_gas_burn_end = None module-attribute

neutral gas temperature in chamber (K)

m_vv_vacuum_duct_shield = None module-attribute

mass of vacuum duct shield (kg)

dia_vv_vacuum_ducts = None module-attribute

diameter of duct passage (m)

n_vac_pumps_high = None module-attribute

number of high vacuum pumps

i_vac_pump_dwell = None module-attribute

switch for dwell pumping options:

• =0 pumping only during t_plant_pulse_dwell
• =1 pumping only during t_plant_pulse_coil_precharge
• =2 pumping during t_plant_pulse_dwell + t_plant_pulse_coil_precharge

The following are used in the Battes, Day and Rohde pump-down model See "Basic considerations on the pump-down time in the dwell phase of a pulsed fusion DEMO" http://dx.doi.org/10.1016/j.fusengdes.2015.07.011)(i_vacuum_pumping=simple')

f_a_vac_pump_port_plasma_surface = None module-attribute

area of one pumping port as a fraction of plasma surface area

volflow_vac_pumps_max = None module-attribute

maximum pumping speed per unit area for deuterium & tritium, molecular flow

f_volflow_vac_pumps_impedance = None module-attribute

effective pumping speed reduction factor due to duct impedance

pres_vv_chamber_dwell_start = None module-attribute

initial neutral pressure at the beginning of the dwell phase (Pa)

outgasindex = None module-attribute

outgassing decay index

outgasfactor = None module-attribute

outgassing prefactor kw: outgassing rate at 1 s per unit area (Pa m s-1)

init_vacuum_variables()

Initialise Vacuum variables

Source code in process/data_structure/vacuum_variables.py

def init_vacuum_variables():
    """Initialise Vacuum variables"""
    global \
        i_vacuum_pumping, \
        n_iter_vacuum_pumps, \
        i_vacuum_pump_type, \
        n_vv_vacuum_ducts, \
        dlscal, \
        pres_vv_chamber_base, \
        pres_div_chamber_burn, \
        molflow_vac_pumps, \
        outgrat_fw, \
        temp_vv_chamber_gas_burn_end, \
        m_vv_vacuum_duct_shield, \
        dia_vv_vacuum_ducts, \
        n_vac_pumps_high, \
        i_vac_pump_dwell, \
        f_a_vac_pump_port_plasma_surface, \
        volflow_vac_pumps_max, \
        f_volflow_vac_pumps_impedance, \
        pres_vv_chamber_dwell_start, \
        outgasindex, \
        outgasfactor

    i_vacuum_pumping = "old"
    n_iter_vacuum_pumps = 0.0
    i_vacuum_pump_type = 1
    n_vv_vacuum_ducts = 0
    dlscal = 0.0
    pres_vv_chamber_base = 5.0e-4
    pres_div_chamber_burn = 0.36
    molflow_vac_pumps = 1.2155e22
    outgrat_fw = 1.3e-8
    temp_vv_chamber_gas_burn_end = 300.0
    m_vv_vacuum_duct_shield = 0.0
    dia_vv_vacuum_ducts = 0.0
    n_vac_pumps_high = 0
    i_vac_pump_dwell = 0
    f_a_vac_pump_port_plasma_surface = 0.0203
    volflow_vac_pumps_max = 27.3
    f_volflow_vac_pumps_impedance = 0.167
    pres_vv_chamber_dwell_start = 1.0
    outgasindex = 1.0
    outgasfactor = 0.0235