Sample Problem: Time-Dependent Z-Pinch Hohlraum

Setting Up the Grid: Detector with Aperture

Detector:

We simulate the detector by putting a 0.1 cm x 0.1 cm square (a single polygon) along a line-of-sight typical of that used in a Z experiment. The detector polygon is put 10 m away from the pinch (smaller than in experiments, but still large compared to the size of the pinch), as its normal vector faces the pinch. The detector is 12 degrees above the horizontal (78 degrees from vertical).

• Select Target | Add Object.
• Select "Rectangle" for the target component type.
• Set the object name to "Detector".
• In the Position tab of the Object Parameters Dialog:
• For the Reference Coordinate System, use "Target Chamber".
• Use a spherical coordinate system to set the detector position.
• Set the object at: radius = 1000 cm, theta = 78 degrees, phi = 120 degrees.
• Use the orientation angles: polar = 78 degrees, azimuthal = 120 degrees.
• In the Size/Gridding tab of the Object Parameters Dialog:
  • Set both the x-length and y-length to 0.1cm.
  • Set surface normals down.
  • Use 2 grid points in the both the x- and y-directions (this provides 4 nodes, one polygon).
• Select "OK".

Aperture for Detector:

We assume an aperture located a distance of 15.4 cm from the pinch, with a slot height of 0.5 cm and a slot width of 0.7 cm.

• Select Target | Add Object.
• Select "Rectangle" for the target component type.
• Set the object name to "Aperture".
• In the Position tab of the Object Parameters Dialog:
• For the Reference Coordinate System, use "Target Chamber".
• Use a spherical coordinate system to set the aperture position.
• Set the object at: radius = 10 cm, theta = 78 degrees, phi = 120 degrees.
• For orientation angles, set to polar = 78 degrees, azimuthal = 120 degrees.
• In the Size/Gridding tab of the Object Parameters Dialog:
  • Set the x-length to 5 cm and the y-length to 7 cm.
  • Set surface normals down.
  • Use 2 grid points in the both the x- and y-directions
• Select "OK".

We next need to apply a clipping volume equal to the size of the aperture.

• In the Target Components List, select Aperture.
• Then select Target | Clip Object With (or select the Clip Target Component tool button).
• For the clipping volume type, select "Box".
• Rename the clipping volume, if desired.
• In the Position tab of the Clipping Volume Parameters Dialog:
  • Use the default object position: r = (0,0,0).
  • Use the default orientation angles (all zero).
  • For the reference coordinate system, by default clipping volumes use the coordinate system of the object they are clipping.
• In the Size tab of the Clipping Volume Parameters Dialog:
  • Set X to 0.5(this sets the height of the aperture to 0.5cm in this example).
  • Set Y to 0.7(this sets the width of the slot to 0.7 cm).
  • Set Z to 0.1 (this depth is arbitrary).
  • Remove the interior (of the clipping volume).
• Select "OK".