Amount of ray information to be outputted
This note concerns the amount of data to be put in the ‘information’ box and repeated in the ray output data file, the name of which was entered near the beginning of the data file. The amount of information is chosen by the user. The main choices are 'nearlyzero/partial/most/all', but see below for some more specialised options.
The usual entry is 'partial'.
The information outputted at the various printing levels is:
(1) 'nearly zero': Ray information at the test planes. These data are a form suitable for use in a subsequent calculation (see below).
(2) 'partial': Partial ray information plus information at all the test planes. Headings of tabulated data are sometimes omitted to aid in the subsequent editing or use of these data..
(3) 'most': Complete ray information, except that information on interpolated points is omitted. Headings of tabulated data are sometimes omitted to aid in the subsequent editing or use of these data.
(4) 'all': Complete ray information.
Further more specialised options:
(1) 'zero': Gives a minimum of information when voltages are being varied iteratively to focus a beam, as in the 7th 2D example file or the 6th 3D example file.
(2) The option 'nearly zero plus ray and test-plane numbers' is the same as ‘nearly zero’ but at the beginning of each line the number nr of the ray and the number nt of the test-plane are added. If a ray hits a segment before the test plane is reached then the coordinates of the hitting point are given and –nt is used instead of nt. If a ray neither crosses the test-plane nor hits a segment then 0 is used instead of nt.
(3) The option 'all + fields' for rays is included only for diagnostic purposes (for example in connection with testing oscillating voltage wave-forms). An extra line at each step gives the x,y,z components of the electric field followed by the magnitude of the total field. If a magnetic field exists the analogous information is given in another extra line.
(4) To omit all headings and text (while retaining the numbers) for segments and rays click on ‘no headers’ on the ‘segments and charges’ sheet. This puts nh (for 'no headings') in the first two spaces of the caption line -that is, the first line of the input data file.
(5) To separate data by commas, which can be useful for processing data with an external program package, click on ‘separate by commas’ below the ‘no headers’ button. This puts nhc in the first three spaces of the caption line.
(6) To output the minimum and maximum coordinates and velocity components of each of the traced rays click on the relevant button on the 'ray' sheet.
In CPO3D there is a choice of outputting either the distance from the origin or the distance from the z axis.
Obtaining ray data that have the correct format for re-use as initial data in a subsequent calculation.
For the nearly-zero print level the output ray data are (for 3D) the values of: x, y, z, cx, cy, cz, kinetic energy, time , current at each test plane and ray, where cx, cy and cz are direction cosines. These data have the correct format for re-use as initial data in a subsequent calculation, such as when a two-stage solution is in use.
Further information on the nearly-zero print level:
Hitting points are used if the test plane is not reached.
The cathode segment area is also given when relevant.
The charge and mass are added when they are variables.
The total current is also given for cathode calculations.
The time is also added at the end.
Finally, the output data is usually overwritten at each run, but there is an option to make the information cumulative. It can be found on the screen in which the output files are named.
Return to general information on printing levels.
For users who are editing or constructing an 'input data file' without the use of the data-builder -that is, pre-processor:
But Manual editing is certainly not recommended -it is a relic from the time when the databuilder was not available All users are strongly encouraged to use the databuilder, which always gives the correct formats and which has many options for which the formats are not described or easily deduced.
The choices for 'nearlyzero/partial/most/all/zero' are denoted in the data file by the letters 'n/p/m/a/z' respectively.
For CPO3D the letter 's' should be put in the third space on the line if the radius (that is, the distance from the origin) is to be tested during the ray tracings (otherwise the quantity tested is always r, the distance from the z axis.
To omit all headings and other words (while retaining the numbers) put nh (for 'no headings') in the first two spaces of the caption line -that is, the first line of the input data file.