Xmpl3d22, 22nd 'example' data file for CPO3D
Practical cylindrical mirror analyzer (CMA)
A practical cylindrical mirror analyzer is simulated with apertures for the beam in the inner cylinder. The presence of the apertures profoundly changes the properties of the analyzer.
This is a 2-dimension simulation and so can be treated more accurately using CPO2D, see the test3d14.dat file.
The file was written when the memory and speed of PC's was much more limited than at present, so the available number of segments was small and the requested inaccuracies were fairly high to give a quick demonstration.
The set up is the same as that in file test3d14.dat, for the ideal cylindrical mirror analyzer, except that
(1) holes are created in the inner cylinder to allow the beam to pass through,
(2) the x=y symmetry plane is removed, and
(3) the range of angles is reduced from 5 to 2.5 degrees.
Details of how the holes are created:
Whole cylinders are used from z = -9 to -2.6, and from z = -1.4 to 0.
A 'cylindrical rectangle' (labelled by 'cre') is used to fill in all the gap except for a square centred at (x,y,z) = (1,0,-2).
Three further 'cre' are then placed around the edges of this square, and are more finely divided than the other electrode elements.
Finally 'cylindrical triangles' ('ctr') are used to fill in the corners of the remaining square.
It can be seen that the performance is poor. The presence of the holes has profoundly altered the properties of the analyzer. As explained by L Frank, J. Phys. E (Sci. Instr.) 9, 670-672 (1976), the holes create diverging lenses.