# ocelot.rad.screen¶

## Module Contents¶

### Classes¶

 Screen Class to store radiation field and to provide information about screen parameters where radiation will be observed.

### Functions¶

 Py2C(array) sum_screens(screen_down, screen_up) the function accumulates the radiations from different emitters which placed in consecutive order (u_down, d, u_up, …).
ocelot.rad.screen.__author__ = Sergey Tomin

Screen class for SR module. The first version was written in 2011 - 2012. S.Tomin

ocelot.rad.screen.Py2C(array)
class ocelot.rad.screen.Screen

Class to store radiation field and to provide information about screen parameters where radiation will be observed. Format for electric fields in arrays (arReEx, arImEx, …) is following: ReEx[ny*nx*je + nx*jy + jx]

self.z: 100.0 [m], distance from the beginning of the lattice to the screen self.size_x: 1 [m], half of screen size in horizontal plane self.size_y: 1 [m], half of screen size in vertical self.nx: 1, number of points in horizontal plane self.ny: 1, number of points in vertical plane self.start_energy: 100.0 [eV], starting photon energy self.end_energy: 10000.0 [eV], ending photon energy self.num_energy: 1000, number of energy points self.arReEx = [], Real part of horizontal component of the electric field self.arImEx = [], Imaginary part of horizontal component of the electric field self.arReEy = [], Real part of the vertical component of the electric field self.arImEy = [], Imaginary part of the vertical component of the electric field self.arPhase = [], phase between Re and Im components

update(self)
rebuild_efields(self, x0=0, y0=0, z0=0)

the method recalculates the field phase and electrical fields to obtain the correct values that can be used to propagate the wave front.

Parameters
• x0 – initial the electron coordinate

• y0 – initial the electron coordinate

• z0 – initial the electron coordinate

Returns

screen_to_emscreen(self, screen)
create_empty_emclass(self)
nullify(self)
create_like(self, em_screen)
screenPy2C(self, lperiod, nperiods, status)
screenC2Py(self, c_screen)
distPhoton(self, gamma, current)

On the area ds during 1 sec falls dN photons in spectral width (dlambda/lambda) dN = ds/Distance**2 * (dlambda/lambda) * (I/qe) * 3*alpha*gamma**2/(4*pi**2) * |Eul(lambda, Xscreen)|**2 Eul(lambda, Xscreen) is unitless electric field: Eul(lambda, Xscreen) = - (c/qe) * D/(sqrt(3)*gamma**2) * (E(lambda, Xscreen))

Parameters
• gamma

• current – in A

Returns

coherent_photon_dist(self)

On the area ds during 1 sec falls dN photons in spectral width (dlambda/lambda) dN = ds/Distance**2 * (dlambda/lambda) * (I/qe) * 3*alpha*gamma**2/(4*pi**2) * |Eul(lambda, Xscreen)|**2 Eul(lambda, Xscreen) is unitless electric field: Eul(lambda, Xscreen) = - (c/qe) * D/(sqrt(3)*gamma**2) * (E(lambda, Xscreen))

For coherent radiation calculation: I = qe dN = ds/Distance**2 * (dlambda/lambda) * 3*alpha/(4*pi**2) * |Eul(lambda, Xscreen) * gamma * n_e|**2 |Eul(lambda, Xscreen) * gamma * n_e| is calculated in function coherent_radiation()

Returns

zerosArray(self)
screen2dict(self)
dict2screen(self, dictionaty)
ocelot.rad.screen.sum_screens(screen_down, screen_up)

the function accumulates the radiations from different emitters which placed in consecutive order (u_down, d, u_up, …). This means that before summation of screens we must rotate the electric field vectors of a screen_up on angle screen_down.arPhase anticlockwise, because the radiation calculation starts from zero phase from each emitter.