Sample Problem: Cylindrical Halfraum at OMEGA

Setting Up the Grid: Cylindrical Halfraum

Perform the following steps to set up a cylindrical halfraum with laser entrance hole pointing at port H6, and add a circular opening at the end opposite the LEH for a sample package.

• Select Target | Add Object.
• Select "Cylindrical Halfraum" for the target component type.
• Set the object name to "Halfraum".
• In the Position tab of the Object Parameters Dialog:
• For the Reference Coordinate System, select the Port Axis radio button, and select port H6 in the combo box.
• Use the default object position: r = (0,0,0). That is, put the centroid of the halfraum at target chamber center.
• In the Size/Gridding tab of the Object Parameters Dialog:
  • Set the radius to 0.08 cm (800 microns).
  • Set the length to 0.12 cm, and LEH radius to 0.06 cm.
  • (For all pre-configured hohlraums, surface normals face inward.)
  • Use 11 grid points along the Z-axis.
  • Set the number of azimuthal grid points to 18 (20 degrees per node).
  • For the top disk (LEH side) of the hohlraum, use 3 radial grid points. For the bottom, use 4 radial grid points.
• Select "OK". (The halfraum is added to the graph frame.)

We next need to apply clipping volumes to make an opening in the bottom disk of the halfraum.

• In the Target Components List, select Halfraum (single-click with the mouse).
• Then select Target | Clip Object With (or select the Clip Target Component tool button).
• For the clipping volume type, select "Cylinder".
• Rename the clipping volume, if desired.
• In the Position tab of the Clipping Volume Parameters Dialog:
  • Note that the reference coordinate system is the coordinate system of the object being clipped.
  • Set the position of the clipping object at the bottom of the halfraum: r = ( 0, 0, -0.06).
  • For orientation angles, use the default values (all zero). By default, cylinders are aligned along the z-axis. Thus, the axis of symmetry of the clipping cylinder is aligned along the symmetry axis of the halfraum.
• In the Size tab of the Clipping Volume Parameters Dialog:
  • Set the radius to 0.04 cm..
  • Set the length to 0.1 cm. (this is somewhat arbitrary; it only needs to have sufficient depth to clip the bottom disk of the halfraum).
  • Remove the interior (of the clipping volume).
• Select "OK". (An opening appears in the bottom of the halfraum. See image below.)

  

When a clipping volume is added, its name appears in the Target Component List under the object to which it is being applied. To edit the clipping volume, just double-click (left mouse) on the clipping volume name.

To view the clipping volumes while building the grid, selected Show | Clipping Volumes.