xmpl3d58, scattering option, secondaries

xmpl3d58, 58th 'example' data file for CPO3D

Illustration of the user-supplied scattering option, production of secondary electrons

58th example file, to illustrate the user-defined scattering option, which is available only in the 'special' scattering version of CPO3D or CPO3DS.

The geometry is that of xmpl3d49.dat.

50 rays start at z = -0.5 and produce secondary electrons when they the electrode at z=1.

The rays have an initial energy of 100eV and the secondaries have a lambertian angular distribution. They also have a maxwellian energy distribution (see Help) with a maximum probability at emax = 1eV and a mean energy 3*emax.

A weak retarding field is used to reflect the secondaries.

The external 'user-supplied' routine that defines the scattering function is in file sct3secd.cpp, which is supplied with the CPO3D package. It should be copied to scatter3.cpp and used to create scatter3.dll, as explained in Help.

This routine calls the data file sct3secd.dat (also supplied with the package), which is named by the user in the databuilder.

Please see sct3secd.cpp for more detailed information.

Internal options are also available for producing secondary electrons, see xmpl2dn where n = 26 and 39, and xmpl3dn where n = 49 and 61.

Technical notes:

1. The x and y ray limits are used to stop the secondaries passing through the sides of the box.

2. The option to stop rays at the 3rd crossing of an electrode is used to stop the secondaries passing through the end face after reflection. We use the 3rd crossing because the 1st crossing is effectively the initial crossing of the primary before it is truncated at the end plate and the 2nd crossing is effectively caused by the newly created secondary.

3. The number of interpolation points used for the display is set to zero because the interpolation routine is unable to deal with these sharply reflected rays.

4. In scatter3.cpp (copied from sct3secd.cpp) secondaries are not produced if the primary energy is less that 10 times the maximum secondary energy. This is necessary to prevent further secondaries being produced when a secondary hits the end plate.

5. There is a 2nd test plane at z=0.99, second crossing, so that the distribution of secondary electron energies can be monitored.