The FEL Calculation Program ("ELOP") can calculate two main concepts:

1. Magnetic field in different magnetic elements, such as magnetic coils, permanent magnets and magnet pairs, wiggler (which consists of permanent magnets), quadrupole magnets and so on.

2. Electron trajectory in given electric and magnetic field as the result of Lorentz force.

1. First of all you have to choose your system configuration.

   There exist 5 configuration windows, where system parameters can be changed:

   • Wiggler Configuration Window - Fig.1

     In this windows you can choose your wiggler configuration: wiggler properties, dimensions of magnet, saturating field, electron energy and so on.

     Wiggler Parameters:

     a0, b0, c0 - dimensions of wiggler magnets al, bl, cl - dimensions of longitudional magnets Saturating Field - magnetic field on the magnet surface z0, dl - coordinates of the center of longitudional magnet (in cylindrical coordinates) Gap - distance between internal edges of wiggler magnets at the wiggler entrance Periods account for - maximum number of periods taken into account for magnetic field calculation

   • Additional Magnets Window - Fig.2

     In this window the configuration of additional magnets (if exist) can be chosen. You can change the number of magnets and its parameters.

     Additional magnets parameters:

     • d - half distance between magnet centers
     • l - longitudional distance between regular and additional magnets
     • alpha - additional magnets magnetic field direction
     • Xm, Ym, Zm - magnet coordinates
     • betha - magnetic field direction in perpendicular plane
     • Bs/1A - effective saturating field to current relation for the steering magnet model

   • Quads Configuration Window - Fig.3

     This window make it possible to change the configuration of quads: their position, dimension and field characteristic.

     Quads parameters:

     • Effective field width - effective width of quad magnetic field
     • Field gradient - quad magnetic field for the distance of 1 mm off the axis and current of 1A
     • Quad currents - exitation currents in quadroupoles

   • Injection Coils Configuration Window - Fig.4

     In this window you can change the configuration of injection coils: their position, number of turns, diameter, coils currents, external field and electron energy.

   • Additional Coils Window - Fig.5

     This window gives you the opportunity to add additional coils to your system and to choose their properties.

     There are three possible choices:

     • open air focusing coils with axial magnetic field - Focusing Coils
     • pair of open air steering coils with perpendicular magnetic field - Steering Coils
     • model of permanent magnets for iron core steering coils (magnet parameters were chosen to fit best the experimental measurements of the real magnet fields) - ULCA type Steering Coils

     Coil Parameters:

     • D - diameter of the coil
     • z, x, y - coordinates of the coil
     • N - number of turns
     • I - current

2. Now you are ready to run the programm.

   The next step is to choose the concept you want to calculate:

   • Calculation of Magnetic Field Window - Fig.6

     In this window you can choose number of calculation points, initial point coordinates and inclination, and the output file name.

     Parameters:

     • Xi, Yi, alphaX, alphaY - initial coordinates and inclination of the axis of calculation

   • Calculation of Electron Trajectory Window - Fig.7

     Here you can choose number of calculation points, initial point coordinates, initial beam parameters, number of particles you want to calculate, and the output file name.

     Parameters:

     • X0, Y0 - initial position of the beam center
     • alphaX0, alphaY0 - initial beam inclination
     • èx, èy - electron beam emittance characetristics: x- and y- waist maximal divergence angles
     • Rx0, Ry0 - electron beam waist parameters: x- and y-direction half-radius

3. Press button and wait for the results!