Spherical Tokamak

• This is characterized by a blanket that only goes around the outboard sides of the plasma and a center column that has no inboard breeding.

Spherical tokamak

• The spherical_tokamak function provides a parametric tokamak shaped reactor.

• This is characterized by a blanket that only goes around the outboard sides of the plasma.

• This reactor allows for a separate vertical and radial build which allows different thickness layers in the blanket.

import paramak

result = paramak.spherical_tokamak(
    radial_build=[
        (paramak.LayerType.GAP, 10),
        (paramak.LayerType.SOLID, 50),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    vertical_build=[
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.SOLID, 120),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 700),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 30),
        (paramak.LayerType.SOLID, 15),
    ],
    rotation_angle=180,
    triangularity=0.55,
).toCompound()

Spherical tokamak from plasma

• The spherical_tokamak_from_plasma function provides a parametric tokamak shaped reactor.

• This reactor requires minimal arguments to create as it keeps the vertical build of the blanket layers the same thickness as the radial build.

import paramak
result = paramak.spherical_tokamak_from_plasma(
    radial_build=[
        (paramak.LayerType.GAP, 10),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 20),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 20),
        (paramak.LayerType.SOLID, 120),
        (paramak.LayerType.SOLID, 10),
    ],
    elongation=2,
    triangularity=0.55,
    rotation_angle=90,
).toCompound()

Spherical tokamak with divertor

• Reactors support adding additional extra intersect shapes that can be used as a divertor.

• This example adds a divertor to a spherical_tokamak_from_plasma reactor.

import paramak
from cadquery import Workplane

# makes a rectangle that overlaps the lower blanket under the plasma
# the intersection of this and the layers will form the lower divertor
points = [(200, -700), (200, 0), (300, 0), (300, -700)]
divertor_lower = Workplane('XZ', origin=(0,0,0)).polyline(points).close().revolve(180)
result = paramak.spherical_tokamak_from_plasma(
    radial_build=[
        (paramak.LayerType.GAP, 10),
        (paramak.LayerType.SOLID, 50),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    elongation=2,
    triangularity=0.55,
    rotation_angle=180,
    extra_intersect_shapes=[divertor_lower]
).toCompound()

Spherical tokamak with custom divertor

• The revolved_shape function builds a solid by revolving a custom 2D (R, Z, connection) profile. Here straight segments make a small V-shaped divertor plate.

• This example adds the revolved shape directly to the reactor assembly with assembly.add, rather than passing it to extra_intersect_shapes. The plate therefore keeps its full shape and can sit anywhere inside the vessel, outside the blanket envelope — it is not clipped to the blanket.

• For the alternative approach, where the revolved shape is intersected with the blanket so the divertor is confined to the blanket envelope, see the Tokamak with custom divertor example.

import cadquery as cq
import paramak

# small V-shaped divertor plate from straight segments, sitting in the
# lower cavity between the plasma and the lower blanket
points = [
    (160, -312, "straight"),
    (220, -336, "straight"),
    (280, -312, "straight"),
    (280, -330, "straight"),
    (220, -354, "straight"),
    (160, -330, "straight"),
]
divertor = paramak.revolved_shape(points=points, rotation_angle=180, plane="XZ")

result = paramak.spherical_tokamak_from_plasma(
    radial_build=[
        (paramak.LayerType.GAP, 10),
        (paramak.LayerType.SOLID, 50),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    elongation=2,
    triangularity=0.55,
    rotation_angle=180,
)

# add the divertor plate directly to the assembly so it is not clipped to the blanket
result.add(divertor, name="divertor", color=cq.Color("red"))
result = result.toCompound()

Spherical tokamak with poloidal field coils

• All reactors support adding a sequence of CadQuery shapes (e.g. workplanes) to the reactor using the extra_cut_shapes argument.

• This example adds PF coils to a spherical_tokamak_from_plasma reactor but any other reactor would also work.

import paramak

extra_cut_shapes = []
for case_thickness, height, width, center_point in zip(
    [10, 15, 15, 10], [20, 50, 50, 20], [20, 50, 50, 20],
    [(500, 300), (560, 100), (560, -100), (500, -300)]
):
    extra_cut_shapes.append(
        paramak.poloidal_field_coil(
            height=height, width=width, center_point=center_point, rotation_angle=270
        )
    )
    extra_cut_shapes.append(
        paramak.poloidal_field_coil_case(
            coil_height=height,
            coil_width=width,
            casing_thickness=case_thickness,
            rotation_angle=270,
            center_point=center_point,
        )
    )

result = paramak.spherical_tokamak_from_plasma(
    radial_build=[
        (paramak.LayerType.GAP, 10),
        (paramak.LayerType.SOLID, 50),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    elongation=2,
    triangularity=0.55,
    rotation_angle=270,
    extra_cut_shapes=extra_cut_shapes,
).toCompound()

Spherical tokamak with toroidal field coils

• In a similar way to adding poloidal field coils one can also add toroidal field coils by making use of the extra_cut_shapes argument.

• All reactors support adding a sequence of CadQuery shapes (e.g. workplanes) to the reactor using the extra_cut_shapes argument.

• This example adds TF coils to a spherical_tokamak_from_plasma reactor but any other reactor would also work.

• Also these are rectangle shaped TF coils but other shapes are also available.

import paramak

tf_style_1 = paramak.toroidal_field_coil_rectangle(
    horizontal_start_point = (10, 520),
    vertical_mid_point = (600, 0),
    thickness = 50,
    distance = 40,
    rotation_angle = 180,
    with_inner_leg = True,
    azimuthal_placement_angles = [0, 30, 60, 90, 120, 150, 180],
)

result1 = paramak.spherical_tokamak_from_plasma(
    radial_build=[
        (paramak.LayerType.GAP, 70),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    elongation=2.5,
    rotation_angle=180,
    triangularity=0.55,
    extra_cut_shapes=[tf_style_1]
).toCompound().translate((700, 0, 0))

tf_style_2 = paramak.toroidal_field_coil_princeton_d(
    r1=5,
    r2=610,
    azimuthal_placement_angles = [0, 30, 60, 90, 120, 150, 180],
    rotation_angle = 180,
    thickness = 50,
    distance = 40
)

result2 = paramak.spherical_tokamak_from_plasma(
    radial_build=[
        (paramak.LayerType.GAP, 70),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    elongation=2.5,
    rotation_angle=180,
    triangularity=0.55,
    extra_cut_shapes=[tf_style_2]
).toCompound().translate((-700, 0, 0))

import cadquery as cq
result = cq.Assembly()
result.add(result1, name="rectangular_tf")
result.add(result2, name="princeton_d_tf")
result = result.toCompound()

Spherical tokamak with negative triangularity

• The triangularity argument can be set to a negative value to make a plasma with a negative triangularity.

• This example makes a spherical tokamak with a negative triangularity but this would work on any reactor.

import paramak

result = paramak.spherical_tokamak(
    radial_build=[
        (paramak.LayerType.GAP, 10),
        (paramak.LayerType.SOLID, 50),
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 300),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 40),
        (paramak.LayerType.SOLID, 60),
        (paramak.LayerType.SOLID, 10),
    ],
    vertical_build=[
        (paramak.LayerType.SOLID, 15),
        (paramak.LayerType.SOLID, 80),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.GAP, 50),
        (paramak.LayerType.PLASMA, 700),
        (paramak.LayerType.GAP, 60),
        (paramak.LayerType.SOLID, 10),
        (paramak.LayerType.SOLID, 40),
        (paramak.LayerType.SOLID, 15),
    ],
    rotation_angle=180,
    triangularity=-0.55,
).toCompound()