Adding Target Components

To add a target component to the grid, select the Target | Add Object menu item. This can also be accomplished by using the Add Target Component button () on the toolbar.

The user then selects the type of object to be added:

Upon selection of the object type, the user is presented with the Object Parameters Dialog.

The primitives Cylinder, Cone, Sphere, Box, Torus, Helix, Disk, Spokes, Polygon, Rectangle, Slotted Hohlraum, and Surface of Revolution are each represented as a single geometric "object".

Cylindrical Hohlraum, Cylindrical Halfraum, Rugby Hohlraum, and Tetrahedral Hohlraum are composed of several geometric primitives. For example, Cylindrical Hohlraums are made up of one cylinder and disks at the ends of the cylinder, while Tetrahedral Hohlraums are composed of a single sphere and 4 transparent disks representing the laser entrance holes (LEHs).

A Cylindrical Halfraum, while normally constructed with disk at the bottom (i.e., with no hole), can be constructed with an opening at the bottom, thereby effectively creating a Cylindrical Hohlraum with LEHs of two different sizes.

Generation of portions of Cylinders, Cones, Disks, Toruses, Spheres and Surfaces of Revolution is also supported in VISRAD.

A Rugby Hohlraum is defined by the intersection of two circles in a plane, and rotating that surface about an axis of symmetry (the z-axis). Mathematically, this can be expressed as: (ρ+D)²+z²=R², where (ρ,z) is the position of a point on the surface (cylindrical coordinate system), R is the radius of curvature of the circles, and D is the distance from the center of the hohlraum to the center of one of the circles. R and D are determined from specification of the hohlraum length, and the radius at the top/bottom of the hohlraum.

A Surface of Revolution is an object that is cylindrically symmetric about the z-axis, and the radial location of the surface, r, is specified as a function of the z position using an analytic expression, r(z). Note that when evaluating r(z), the value of z is always assumed to be in units of cm.

Polygon objects must be convex, but can be regular (equal length sides and angles) or irregular. Polygon objects can be zero-thickness or have a user-specified height. For irregular polygons, polygon node positions can be adjusted using the mouse.

A Multi-Element object is composed of multiple primitives (i.e., elements), which utilize a common set of parameters to specify their Position and Size/Grid information. For addition information on Multi-Element objects, see Setting up Multi-Element objects.

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