P.track location form density/radius integrate time
The P.TRACK line defines a particle track which can subsequently be activated on a transient simulation sequence (see the "seu" option on the SOLVE line).
ORIgin = vector (default is [0,0,0]) ENdpoint = vector (default is [0,0,0]) TRack = vector (default is [0,0,0])
ORIGIN defines the starting [x,y,z] coordinates of the particle track. The remainder of the track can be defined using the ENDPOINT - again as [x,y,z] - or by TRACK which is given as [r, theta, phi] where r is a depth (in mm) and theta, phi are strike angles to the yz- and xz-planes.
form
Uniform = logical (default is false) Gaussian = logical (default is false) Power = logical (default is false) CUt.power = logical (default is false) RAnge.power = real (default is infinity)
The form of the generation function generated by the particle track is given by one of the parameters UNIFORM, GAUSSIAN, POWER or CUT.POWER; if none of the options are specified, the default is taken as UNIFORM. All the distributions have radial symmetry about the track. The radius of the uniform profile or characteristic length of the gaussian can vary along the track, as described below. The power distribution decays from the track as (1+|r|/sigma)**-n where n and sigma are defined below. CUT.POWER is a power distribution whose extent radially ends at RANGE.POWER (in mm).
density/radius
Density = real Volume = logical (default is false) Radius = real SIgma = real EXp.power = real TAble = character
The density and radius/sigma along the track can be defined either: (1) as constants using DENSITY, RADIUS, SIGMA or (2) by a table of (distance,density,radius/sigma) values in a file called TABLE. The density units are taken as linear densities (eh-pairs/mm) if VOLUME=false, or local volume densities (eh-pairs/cm**3) if VOLUME=true. Distances are in mm. For power distributions, the exponent n (see above) is defined by EXP.power or as a fourth column in the input file, if TABLE is specified.
integrate
ORDer = integer (default is 5) Level = integer (default is 0) Conserve = logical (default is true) E.thresh = real (default is 0.01)
ORDER is the quadrature order applied to the integration of the charge over control volume pairs in each element; the highest order implemented is 5. For more accuracy, the control volume subsections can be uniformly refined LEVEL times. The CONSERVE option scales the specified density to assure the the total dose matches the exact integral of the specified radial function; with CONSERVE off, the dose may not be preserved on coarse grids due to discretization error. The exact and numerically integrated rates are always printed in the output file (the scale factor is taken from these rates if CONSERVE is on). E.THRESH defines a threshold (as a fraction of the total dose) generation at electrodes which will induce an error; this charge will by default be assigned over the remainder of the track.
time
TIme = real vector
By default, the charge generated by the particle track is distributed equally (square pulse) over an intervals specified on SOLVE lines. TIME gives the decay rate tau and peak tp (in sec) for a quasi-Gaussian distribution in time:
As with the pulse, the Gaussian is included on all SOLVE lines where SEU is turned on.
Define a particle track of length 15mm with a constant linear density of 1.8E6 e-h pairs/mm. The charge will be distributed uniformly outward from the track to a radius of 0.05mm. In time, the charge is generated as a one-sided Gaussian with a decay rate of 30ps and a peak at t=10ps.
P.TRACK UNIF RADIUS=.05 DENSITY=1.8e6 ORIGIN=0,0,0 + END=0,15,0 TIME=30e-12,10e-12
Define a particle track of length 10mm which has a Gaussian distribution laterally in space with density and radius along the track specified in the file "gentbl". The charge will be generated as a pulse in time, with pulse width determined on the SOLVE line. Extra accuracy in the integration is achieved by using 2 levels of refinement of the control volumes.
P.TRACK GAUSS TABLE=gentbl LEVEL=2 ORIGIN=0,0,0 + END=5.7735,5.7735,5.7735