WIP: Improve regularisation documentation and add ADMT demo

cherab/generomak/diagnostics/__init__.py

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+from .bolometers import load_bolometers

cherab/generomak/diagnostics/bolometers.py

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+"""
+Some foil bolometers for measuring total radiated power.
+"""
+from raysect.core import (Node, Point3D, Vector3D, rotate_basis,
+                          rotate_x, rotate_y, rotate_z, translate)
+from raysect.optical.material import AbsorbingSurface
+from raysect.primitive import Box, Subtract
+
+from cherab.tools.observers import BolometerCamera, BolometerSlit, BolometerFoil
+
+
+# Convenient constants
+XAXIS = Vector3D(1, 0, 0)
+YAXIS = Vector3D(0, 1, 0)
+ZAXIS = Vector3D(0, 0, 1)
+ORIGIN = Point3D(0, 0, 0)
+# Bolometer geometry, independent of camera.
+BOX_WIDTH = 0.05
+BOX_WIDTH = 0.1
+BOX_HEIGHT = 0.07
+BOX_DEPTH = 0.2
+THICKNESS = 1e-3
+SLIT_WIDTH = 0.004
+SLIT_HEIGHT = 0.005
+FOIL_WIDTH = 0.0013
+FOIL_HEIGHT = 0.0038
+FOIL_CORNER_CURVATURE = 0.0005
+FOIL_SEPARATION = 0.00508  # 0.2 inch between foils
+
+
+def _make_bolometer_camera(slit_sensor_separation, sensor_angles, sensor_rotations):
+    """
+    Build a single bolometer camera.
+
+    The camera consists of a box with a rectangular slit and 4 sensors,
+    each of which has 4 foils.
+
+    In its local coordinate system, the camera's slit is located at the
+    origin with its width along the X axis and its height along the y
+    axis, and the sensors are below the z=0 plane looking up towards the
+    slit.
+
+    The sensors are rotated by sensor_angles about the y axis to form a
+    fan, and by sensor_rotations about the axis defined by the line
+    between the slit and the sensor. A rotation of 180 degrees flips
+    the sensor upside down and therefore reverses the spatial ordering
+    of lines of sight relative to a rotation of 0 degrees.
+    """
+    camera_box = Box(lower=Point3D(-BOX_WIDTH / 2, -BOX_HEIGHT / 2, -BOX_DEPTH),
+                     upper=Point3D(BOX_WIDTH / 2, BOX_HEIGHT / 2, 0))
+    # Hollow out the box: it has 1 mm thick walls.
+    inside_box = Box(lower=camera_box.lower + Vector3D(THICKNESS, THICKNESS, THICKNESS),
+                     upper=camera_box.upper - Vector3D(THICKNESS, THICKNESS, THICKNESS))
+    camera_box = Subtract(camera_box, inside_box)
+    # The slit is a hole in the box. Make it thicker than the wall.
+    aperture = Box(lower=Point3D(-SLIT_WIDTH / 2, -SLIT_HEIGHT / 2, -1.1 * THICKNESS),
+                   upper=Point3D(SLIT_WIDTH / 2, SLIT_HEIGHT / 2, 0.1 * THICKNESS))
+    camera_box = Subtract(camera_box, aperture)
+    camera_box.material = AbsorbingSurface()
+    bolometer_camera = BolometerCamera(camera_geometry=camera_box)
+    # The bolometer slit in this instance just contains targeting information
+    # for the ray tracing, since we have already given our camera a geometry
+    # The slit is defined in the local coordinate system of the camera
+    slit = BolometerSlit(slit_id="Example slit", centre_point=ORIGIN,
+                         basis_x=XAXIS, dx=SLIT_WIDTH, basis_y=YAXIS, dy=SLIT_HEIGHT,
+                         parent=bolometer_camera)
+    for j, (angle, rotation) in enumerate(zip(sensor_angles, sensor_rotations)):
+        # 4 bolometer foils, spaced at equal intervals along the local X axis
+        sensor = Node(name="Bolometer sensor", parent=bolometer_camera)
+        sensor.transform = (
+            rotate_y(angle)
+            * rotate_z(rotation)
+            * translate(0, 0, -slit_sensor_separation)
+        )
+        for i, shift in enumerate([-1.5, -0.5, 0.5, 1.5]):
+            # Note that the foils will be parented to the camera rather than the
+            # sensor, so we need to define their transform relative to the camera.
+            foil_transform = sensor.transform * translate(shift * FOIL_SEPARATION, 0, 0)
+            foil = BolometerFoil(detector_id="Foil {} sensor {}".format(i + 1, j + 1),
+                                 centre_point=ORIGIN.transform(foil_transform),
+                                 basis_x=XAXIS.transform(foil_transform), dx=FOIL_WIDTH,
+                                 basis_y=YAXIS.transform(foil_transform), dy=FOIL_HEIGHT,
+                                 slit=slit, parent=bolometer_camera, units="Power",
+                                 accumulate=False, curvature_radius=FOIL_CORNER_CURVATURE)
+            bolometer_camera.add_foil_detector(foil)
+    return bolometer_camera
+
+
+def load_bolometers(parent=None):
+    """
+    Load the Generomak bolometers.
+
+    The Generomak bolometer diagnostic consists of multiple 16-channel
+    cameras. Each camera has 4 4-channel sensors inside.
+
+    * 2 cameras are located at the midplane with purely-poloidal,
+      horizontal views.
+    * 1 camera is located at the top of the machine with purely-poloidal,
+      vertical views.
+    * 2 cameras have purely tangential views at the midplane.
+    * 1 camera has combined poloidal+tangential views, which look like
+      curved lines of sight in the poloidal plane. It looks at the lower
+      divertor.
+
+    Channel ordering is as follows:
+    * Poloidal channels are ordered anti-clockwise by line-of-sight:
+      channel 1 of HozPol1 views the top of the machine and channel 16
+      HozPol2 views the bottom of the machine. Similarly, channel 1 of
+      VertPol views the high field side and channel 16 views the low
+      field side.
+    * Tangential channels are ordered by increasing tangency radius:
+      channel 1 of TanMid1 has its tangency radius on the high field
+      side and channel 16 has its tangency radius on the low field side.
+    * The combined tangential/poloidal channels follow both conventions:
+      channel 1 views the high field side and channel 16 views the low
+      field side.
+
+    :param parent: the scenegraph node the bolometers will belong to.
+    :return: a list of BolometerCamera instances, one for each of the
+             cameras described above.
+    """
+    # The coordinate system conventions are as follows. All angles are in
+    # degrees and increase clockwise when viewing along the relevant axes:
+    # y axis for poloidal rotation, z axis for toroidal rotation and x axis
+    # for radial rotation.
+    # - rotation_poloidal: viewing angle of the slit in the poloidal plane,
+    #                      with 0 being horizontally inwards.
+    # - rotation_toroidal: viewing angle of the slit in the toroidal plane,
+    #                      with 0 being purely radial.
+    # - rotation_radial: rotation about the radial axis, 0 being vertically upwards.
+    # - origin: position of the slit relative to the (x, z) poloidal plane i.e. y=0.
+    # - slit_sensor_separation: distance between slit and each 4-channel sensor.
+    # - sensor_angles: angle between slit normal and sensor normal.
+    # - sensor_rotations: rotation angle about the slit-sensor vector, enables
+    #                     reversing the order of lines of sight spatially within
+    #                     each sensor.
+    # - toroidal_angle: the angle of the poloidal plane in which the origin is
+    #                   definied, with 0 being the (x, z) plane.
+    camera_properties = {
+        'HozPol1': {},  # Horizontal poloidal
+        'HozPol2': {},  # Horizontal poloidal,
+        'VertPol': {},  # Vertical poloidal
+        'TanMid1': {},  # Tangential
+        'TanPol1': {}   # Combined poloidal/tangential
+    }
+    # poloidal rotations
+    camera_properties['HozPol1']['rotation_poloidal'] = 30
+    camera_properties['HozPol2']['rotation_poloidal'] = -30
+    camera_properties['VertPol']['rotation_poloidal'] = -90
+    camera_properties['TanMid1']['rotation_poloidal'] = 0
+    camera_properties['TanPol1']['rotation_poloidal'] = -25
+    # toroidal rotation
+    camera_properties['HozPol1']['rotation_toroidal'] = 0
+    camera_properties['HozPol2']['rotation_toroidal'] = 0
+    camera_properties['VertPol']['rotation_toroidal'] = 0
+    camera_properties['TanMid1']['rotation_toroidal'] = -40
+    camera_properties['TanPol1']['rotation_toroidal'] = 40
+    # radial rotation
+    camera_properties['HozPol1']['rotation_radial'] = -90
+    camera_properties['HozPol2']['rotation_radial'] = -90
+    camera_properties['VertPol']['rotation_radial'] = -90
+    camera_properties['TanMid1']['rotation_radial'] = 0
+    camera_properties['TanPol1']['rotation_radial'] = 0
+    # origins relative to the poloidal (x, z) plane
+    camera_properties['HozPol1']['origin'] = Point3D(2.45, 0.05, 0)
+    camera_properties['HozPol2']['origin'] = Point3D(2.45, -0.05, 0)
+    camera_properties['VertPol']['origin'] = Point3D(1.3, 0, 1.42)
+    camera_properties['TanMid1']['origin'] = Point3D(2.5, 0, 0)
+    camera_properties['TanPol1']['origin'] = Point3D(2.2, 0, -0.8)
+    # slit-sensor separations
+    camera_properties['HozPol1']['slit_sensor_separation'] = 0.08
+    camera_properties['HozPol2']['slit_sensor_separation'] = 0.08
+    camera_properties['VertPol']['slit_sensor_separation'] = 0.05
+    camera_properties['TanMid1']['slit_sensor_separation'] = 0.1
+    camera_properties['TanPol1']['slit_sensor_separation'] = 0.15
+    # sensor angles relative to the slit
+    camera_properties['HozPol1']['sensor_angles'] = [22.5, 7.5, -7.5, -22.5]
+    camera_properties['HozPol2']['sensor_angles'] = [22.5, 7.5, -7.5, -22.5]
+    camera_properties['VertPol']['sensor_angles'] = [36, 12, -12, -36]
+    camera_properties['TanMid1']['sensor_angles'] = [18, 6, -6, -18]
+    camera_properties['TanPol1']['sensor_angles'] = [-12, -4, 4, 12]
+    # sensor rotation relative to the slit
+    camera_properties['HozPol1']['sensor_rotations'] = [0, 0, 0, 0]
+    camera_properties['HozPol2']['sensor_rotations'] = [0, 0, 0, 0]
+    camera_properties['VertPol']['sensor_rotations'] = [0, 0, 0, 0]
+    camera_properties['TanMid1']['sensor_rotations'] = [0, 0, 0, 0]
+    camera_properties['TanPol1']['sensor_rotations'] = [180, 180, 180, 180]
+    # toroidal angles about which to rotate the poloidal plane
+    camera_properties['HozPol1']['toroidal_angle'] = 10  # need to avoid LFS limiters
+    camera_properties['HozPol2']['toroidal_angle'] = 10  # need to avoid LFS limiters
+    camera_properties['VertPol']['toroidal_angle'] = 0  # happy to hit LFS limiters
+    camera_properties['TanMid1']['toroidal_angle'] = -15  # avoid LFS limiters
+    camera_properties['TanPol1']['toroidal_angle'] = 15  # avoid LFS limiters
+
+    cameras = []
+    for name, prop in camera_properties.items():
+        camera = _make_bolometer_camera(
+            prop['slit_sensor_separation'],
+            prop['sensor_angles'],
+            prop['sensor_rotations'],
+        )
+        # The transform is applied as follows:
+        # 1. Point the camera along the inward radial direction in the (x, z) plane.
+        # 2. Make the radial, poloidal and toroidal rotations while the camera is at
+        #    the origin.
+        # 3. Move the camera to its position relative to the (x, z) plane.
+        # 4. Rotate the (x, z) plane to the correct toroidal angle.
+        # Transforms are applied right-to-left (or bottom-to-top with one per line):
+        camera.transform = (
+            rotate_z(prop['toroidal_angle'])
+            * translate(prop['origin'].x, prop['origin'].y, prop['origin'].z)
+            * rotate_z(prop['rotation_toroidal'])
+            * rotate_y(prop['rotation_poloidal'])
+            * rotate_x(prop['rotation_radial'])
+            * rotate_basis(-XAXIS, ZAXIS)
+        )
+        camera.parent = parent
+        camera.name = name
+        cameras.append(camera)
+    return cameras