FEL source simulation


Documentation for FEL source simulation can be found on this page.

Data access

Data in archive can be exported using web browser. Initial FEL source can be downloaded from here:

FEL source web site

with authentication (xfel/desy account)

FEL source web site

If you use this dataset, please acknowledge [SALDIN99].

    1. Saldin, E. A. Schneidmiller, and M. V. Yurkov. Nucl. Instrum. and Methods, A(429):233, 1999.

Output data description

The output data is expected in hdf5 format, and the glossary can be found below. FEL source module is responsible for writing out in the format specified below.

FELsource_out_<7 digit ID>.h5 (Output HDF glossary)

Field name Description Data type Units
data/arrEhor Complex EM field written in 4D array, horizontal polarization Float  
data/arrEver Complex EM field written in 4D array, vertical polarization Float  
params/ Parameters for wavefront propagation    
params/Mesh/nSlices Numbers of points vs photon energy/time for the pulse Int  
params/Mesh/nx Numbers of points, horizontal Int  
params/Mesh/ny Numbers of points, vertical Int  
params/Mesh/sliceMax Max value of time [s] or energy [ev] for pulse (fragment) Float s or ev
params/Mesh/sliceMin Min value of time [s] or energy [ev] for pulse (fragment) Float s or ev
params/Mesh/xMax Maximum of horizontal range Float m
params/Mesh/xMin Minimum of horizontal range Float m
params/Mesh/yMax Maximum of vertical range Float m
params/Mesh/yMin Minimum of vertical range Float m
params/Mesh/zCoord Longitudinal position, for FEL output data - length of active undulator   m
params/Rx Instantaneous horizontal wavefront radius Float m
params/Ry Instantaneous vertical wavefront radius Float m
params/dRx Error of wavefront horizontal radius Float m
params/dRy Error of wavefront vertical radius Float m
params/nval complex electric field nval==2 Int  
params/photonEnergy Average photon energy Float ev
params/wDomain Wavefront in time or frequency (photon energy) domain String  
params/wEFieldUnit Electric field units, {sqrt(W/mm^2) (time domain), arbitrary} String  
params/wFloatType Electric field numerical type String  
params/wSpace R-space or Q-space wavefront presentation String  
params/xCentre Horizontal transverse coordinates of wavefront instant ‘source center’ Float m
params/yCentre Vertical transverse coordinates of wavefront instant ‘source center’ Float m
history/parent/info/ Information about input data    
history/parent/info/ contact Contact Information String  
history/parent/info/ data_description Description of FEL data String  
history/parent/info/ method_description Method description String  
history/parent/info/ package_version Package version String  
misc/ Complimentary information    
history/parent/misc/ FAST2XY.DAT FELsource_params_FAST2XY.txt used for post-processing FAST output String  
history/parent/misc/ angular_distribution radial distribution of far field divergence Float  
history/parent/misc/ spot_size near field transverse FEL beam size (FWHM) Float  
history/parent/misc/ gain_curve gain curve, dependence of FEL pulse energy (column 2) from number of working point (column 0) and active undulator length z[cm] (column 1) Float  
history/parent/misc/nzc number of working point defines active undulator length Int  
history/parent/misc/ temporal_struct FEL pulse temporal structure, instantaneous power P(tau) Float  
version hdf5 format version Float 0.1

Diagnostic (diagnostic_felsrc.py)

Fig.1. Pulse irradiance XY map (number of photons per pixel), the title contains size of the pixel;

Fig.2. Pulse time structure, the title contains the pulse energy value.