uids, as it has been described in [14, 19]. narrow neutron guide section. In Fig. 9 the trajectories, that we see in the up- per part of the figure, demonstrate clear zigzag behavior. They have tendency to pass through caustics (dark patches in this figure) and avoid lacunae (white lens-like domains). If a trajectory traverses across a light-colored region, it crosses this region along a shortest route. Since we have mentioned above Henry Fox Tal- bot and his beautiful pattern, Fig. 8, it would be appropriate to consider behavior of the Bohmian trajectories on the Talbot carpet [10]. Their be- havior on the interference Talbot carpets is im- pressive. Fig. 9 shows the Talbot-carpet emer- gent by simulation of scattering monochromatic thermal neutrons ( λ = 0 . 5 nm) on the slit grat- ing containing N = 512 slits. Distance between slits, in this case, is d = 50 λ = 25 nm, so λ/d = 0 . 02 ≪ 1. The Talbot length of that car- pet is z$_{T}$ = 2500 nm. And the ratio of this length to the distance between slits is z$_{T}$/d = 100. So, such Talbot carpet can be observed in a long In conclusion of this section let us consider a hard case of the ratio λ/d , namely d = 10 $^{3}$λ and the ratio is λ/d = 0 . 001. Figs. 10 and 11 show an interference pattern in the near-field region from the grating, having N = 64 slits, and for the case FIG. 11: Interference pattern in the near-field region from the grating N = 64; λ = 0 . 5 nm, d = 500 nm, z$_{T}$ = 1 mm. Arrows a and b point out to bohmian trajectories. FIG. 9: Talbot-carpet near slit sources of slit grating, N = 512. Wavelength λ = 0 . 5 nm, distance between slits d = 50 λ , effective width of slits σ ≈ 0 . 354 a . In the upper part Bohmian trajectories are drawn by alternating violet and blue colors. FIG. 10: Interference pattern in the near-field region from the grating N = 64; λ = 0 . 5 nm, d = 500 nm, z$_{T}$ = 1 mm. Arrows a and b point out to bohmian trajectories. FIG. 8: Optical Talbot effect for monochromatic light, shown as a ”Talbot Carpet”. The figure has been captured from URL http://en.wikipedia.org/wiki/Talbot_effect . 10 /4 z$_{T}$ /2 z$_{T}$ 3 /4 z$_{T}$ z$_{T}$ 0 1600 3200 4800 6400 8000 z / 0 250 x d d d d 0 /4 Z$_{T}$ /2 Z$_{T}$ 3 /4 Z$_{T}$ Z$_{T}$ 2z$_{T}$ 4z$_{T}$ 6z$_{T}$ 8z$_{T}$ 10z$_{T}$ 12z$_{T}$ 14z$_{T}$ 16z$_{T}$ 18z$_{T}$ 20z$_{T}$ d d d d d d d d d a b z$_{T}$ 2z$_{T}$ d d d d d d d d d a b