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    defines an homogenous electric field

    See also MGNFIELD

= largest angle (in degrees) that a particle is allowed to travel in a single step
: 20 degrees
= error of the boundary iteration (minimum accuracy accepted in determining a boundary intersection)
: 0.01 cm
= minimum step if the step is forced to be smaller due to a too large angle
: 0.1 cm
= Ex (x-component of the electric field, in MV/m)
= Ey (y-component of the electric field, in MV/m)
= Ez (z-component of the electric field, in MV/m)
(Ex = Ey = Ez = 0.0): user-supplied subroutine ELEFLD is assumed to provide the actual values (see Notes 2 and 3 below)
: not used
1) If Ex = Ey = Ez = 0, the user-written subroutine ELEFLD is called at each step to get the direction cosines and the module (in MV/m) of the electric field as a function of region or of coordinates or time. A sample subroutine is provided with the FLUKA code; instructions on how to write user-supplied routines can be found in 13}. 2) Note that the argument list of subroutine ELEFLD is ( X, Y, Z, T, ETX, ETY, ETZ, E, NREG, IDISC ) where ETX, ETY, ETZ are the DIRECTION COSINES of the electric field at point X, Y, Z, at time T (NOT the components of the field! The field magnitude is given by E). For this reason, it is imperative that ELEFLD returns normalised values of ETX, ETY and ETZ such that the sum of their squares is = 1.0 IN DOUBLE PRECISION. Three zero values are not accepted: if the field is zero at the point in question, you must return for instance 0, 0, 1 and E = 0. On the contrary, note that Ex, Ey, Ez in the ELCFIELD option, given by
as described above, are the field components and not the cosines. 3) Electric field tracking is performed only in regions defined as electric field regions by command ASSIGNMAt. It is strongly recommended to define as such only regions where an electric field effectively exists, due to the complexity of the tracking algorithm used in electric/magnetic fields. To define a region as having an electric field and to return systematically E = 0 in that region via subroutine ELEFLD, is not allowed. 4) Tracking in electric fields is possible at present only in vacuum regions. Arbitrary combinations of electric and magnetic fields are supported. Whenever an electric field is present the tracking is performed with a Runge-Kutta-Gill 4th order algorithm for the combined electric and magnetic (if any) fields. The same approach can be requested also for dis-homogeneous magnetic fields (in vacuum) even if no electric field is present, using

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