W+T is a device for simulating a point-like source of electrons having an angular distribution with target pattern. Electron gun (not included) is required for its operation.
When electron gun and W+T device are properly aligned and the electrons are scattered from the middle of the wire , the angular distribution is generated by 18 concentric circular slits. Electrons flying through each slit are separated by 1°. It means, that the solid angle of 36° is covered by the pattern of electrons. Such pattern can be used to test the angular scale, acceptance and resolution of the angle-multiplexing analyzers. Example of such a test of one of the FeSuMa Fourier modes is shown below.