  Intergalactic space is believed to contain non-zero magnetic fields (the
Intergalactic Magnetic Field: IGMF) which at scales of Mpc would have
intensities below $10^{-9}$ G. Very high energy (VHE $>$100 GeV) gamma rays
coming from blazars can produce e$^+$e$^-$ pairs when interacting with the
Extragalactic Background Light (EBL) and the Cosmic Microwave Background,
generating an electromagnetic cascade of Mpc scale. The IGMF may produce a
detectable broadening of the emission beam that could lead to important
constrains both on the IGMF intensity and its coherence length. Using the Monte
Carlo-based Elmag code, we simulate the electromagnetic cascade corresponding
to two detected TeV sources: PKS 2155-304 visible from the South and H1426+428
visible from the North. Assuming an EBL model and intrinsic spectral properties
of the sources we obtain the spectral and angular distribution of photons when
they arrive at Earth. We include the response of the next generation Cherenkov
telescopes by using simplified models for CTA (Cherenkov Telescope Array)-south
and CTA-north based on a full simulation of each array performance. Combining
the instrument properties with the simulated source fluxes, we calculate the
telescope point spread function for null and non-null IGMF intensities and
develop a method to test the statistical feasibility of detecting IGMF imprints
by comparing the resulting angular distributions. Our results show that for the
analysed source PKS 2155-304 corresponding to the southern site, CTA should be
able to detect IGMF with intensities stronger than 10$^{-14.5}$G within an
observation time of $\sim$100 hours.
