xmpl3d13, 13th 'example' data file for CPO3D

Cathode ray tube.


A simple cathode ray tube, with variation of the grid voltage to produce a small spot on the screen.


This is a 2-dimensional simulation and so could of course be treated with much greater speed and accuracy by CPO2DS.


The data were obtained 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.


A low inaccuracy has to be used for the rays, 0.0003 in this example, to ensure that the overall spread of voltages, 1000 here, does not lead to large voltage errors in the region of the cathode.

 2 'advanced' options are also illustrated here:

(1) Tracing rays/advanced options/advanced option for step length/  is used to set

 the maximum step length to 0.2 and then to change it to 5 in the region z = 2 to 25,

 -see note on varying step lengths.

(2) Setting up rays/space-charge options/advanced option for tube diameter/  is used

 to set the space-charge tube diameter to 0.02 and then to change it to 0.1 in

 the z region specified by the first option, 2 to 25,

 see note on varying tube diameters.