Evolution of linear and nonlinear processes in time V Zhaunerchyk J H D Eland M Siano L J Frasinski R J Squibb M Kaminska P vd Meulen P Salén M Mucke P Linusson 10.6084/m9.figshare.1012517.v1 https://iop.figshare.com/articles/figure/_Evolution_of_linear_and_nonlinear_processes_in_time/1012517 <p><strong>Figure 4.</strong> Evolution of linear and nonlinear processes in time. As reference, the pulse intensity profile is shown in blue.</p> <p><strong>Abstract</strong></p> <p>We report on a detailed investigation into the electron emission processes of Ne atoms exposed to intense femtosecond x-ray pulses, provided by the Linac Coherent Light Source Free Electron Laser (FEL) at Stanford. The covariance mapping technique is applied to analyse the data, and the capability of this approach to disentangle both linear and nonlinear correlation features which may be hidden on coincidence maps of the same data set is demonstrated. Different correction techniques which enable improvements on the quality of the spectral features extracted from the covariance maps are explored. Finally, a method for deriving characteristics of the x-ray FEL pulses based on covariance mapping in combination with model simulations is presented.</p> 2013-08-13 00:00:00 model simulations electron emission processes nonlinear correlation features data coincidence maps nonlinear processes covariance mapping technique fel covariance maps Different correction techniques pulse intensity profile Ne atoms covariance mapping Linac Coherent Light Source Free Electron Laser Atomic Physics Molecular Physics