Target Frame for the CUP
A target frame used in one of the test experiments is schematically shown here:
The inner radius of the frame depends on the possibility to make a target of a sufficiently large size. Larger inner radius means less particles stopped in the frame, although 17 mm, as shown in the drawing, is unnecessarily large for a well focused beam.
The mounting hole must be situated 20 mm from the center.
The outer radius should not exceed about 25 mm. A too large outer radius makes mounting difficult.
Two small holes opposite to the mounting hole are used for holding the target during mounting. The position of these holes is not strictly defined.
The frame should be as thin as possible (for example 0.1 mm stainless steel). If possible the target should be glued to the frame on its downstream side. If gluing is not possible, and the target is mounted between two frames, the thickness of the downstream frame is critical and should be by no means minimized.
A large surface area of the frame improves heat emission. It is suggested to paint the frame black.