Sample Problem: Cylindrical Halfraum at OMEGA

Setting Up the Grid: Side Shields

In high-intensity laser experiments, it is sometimes useful to place shields in the vicinity of the target to block undesired light from reaching a detector. In this example, two shields are placed on either side of the halfraum. Their placement is shown for the sake of illustrating target component setup only.

Here, two 500 x 500 micron shields are placed on opposite sides of the halfraum, near the LEH.

For the first shield ("Shield_A"):

• Select Target | Add Object.
• Select "Rectangle" for the target component type.
• Set the object name to "Shield_A".
• In the Position tab of the Object Parameters Dialog:
• For the Reference Coordinate System, select "Halfraum".
• To specify the position of the shield, let's use a cylindrical coordinate system; so select "Cylindrical".
• Set the object position at a radius of r = 0.1055 cm (800 microns for the radius of the halfraum, and 250 microns for the half-length of the shield).
• Set the object position at z = 0.055 cm (this is 50 microns along the z-axis below the LEH).
• Use the default orientation angles (all angles zero). This leaves the shield perpendicular with the Halfraum axis.
• In the Size/Gridding tab of the Object Parameters Dialog:
  • Set both the x-length and y-length to 0.05 cm.
  • Set surface normals up.
  • Use 3 grid points along both the x and y directions.
• Select "OK".

For the second shield ("Shield_B"):

• Right-click on Shield_A in the Target Components List, and select Duplicate.
• Double-click on "Shield_A_2" to edit it.
• Use a different object name ("Shield_B").
• In the Position tab, set phi to 180 degrees (this puts the shield on the opposite side of the Halfraum from Shield_A).