One can see, that the both equations, (27) and (28), are linked together. Namely, Eq. (27), HJ-equation, effects to the continuity equa- tion (28) via the velocity ⃗ v = ∇ S/m . In turn, the continuity equation effects to the HJ- equation by means of the quantum potential, since the latter depends essentially on the am- plitude density ρ . Equations (27)-(28) give a rule for computing trajectories, Bohmian trajectories. They dis- close possible paths of the particles from the source to the detector. The rule is given by the guidance equation that has a form According to this equation, position ( x, z ) of the particle in a space reaching behind the slit grat- ing is given by One could think that the Bohmian trajecto- ries are physical artifacts, since they enter into a rough contradiction with the Heisenberg un- certainty principle, because of prediction in each time moment of exact values of coordinates and velocities of the particle. However, one should remember, that the Heisenberg uncertainty prin- ciple relates to procedure of measurements of complementary variables. It means only, that we cannot exactly measure the both variables, the velocity and the coordinate of the particle moving along the Bohmian trajectory. It should be noted, the computations (32) are executed in the paraxial approximation, there- fore the coordinate z is determined by a simple shift. Fig. 7 shows diffraction of monochromatic thermal neutrons ( λ = 0 . 5 nm) from N = 7 slits grating (distance between the slits d = 10 λ and effective slit width σ ≈ 0 . 354 a ). The diffraction pattern shown in this figure covers the near-field zone, z ≤ 4 z$_{T}$ = 400 nm, see Fig. 5. Here and everywhere the Talbot length Wavy curves shown in the upper part of Fig. 7 by alternating violet and blue colors are the Bohmian trajectories calculated according to for- mulas presented above. Alternation of colors permits to discern that the Bohmian trajecto- ries do not intersect as the time t , i.e., z = v$_{z}$t , goes on. One can see, all Bohmian trajectories diverge as they move away from the slits. Draw attention, that the particles, passing through the slits, perform undulatory motions similarly to colored streams of water leaking across break- waters. Such a behavior of quantum objects dis- closes analogy with hydrodynamic flows of liq- Fig. 7 shows a probability density distribution executed in the gray palette ranging from white to black, from zero density to maximal, respec- tively. It is clearly seen, that replicas of the grat- ing begin to disintegrate already in the nearest vicinity of the slits, i.e., at z ≤ 3 / 2 z$_{T}$ . One can see, that at z > 2 z$_{T}$ the replicas disappear fully and transition to the far-field zone takes place. Namely, transformation of the probability den- sity distribution to a characteristic radial radia- tion is observed, see Fig. 5. is adopted as an important scale parameter that divides zones of interference patterns. This length starts from Henry Fox Talbot who discov- ered in 1836 [18] a beautiful interference pattern, Fig 8, that carries his name. FIG. 7: Diffraction in a zone z ≤ 4 z$_{T}$ from 7 slits grating of thermal neutrons ( λ = 0 . 5 nm, distance between slits d = 10 λ , effective slit width σ ≈ 0 . 354 a ). Wavy curves drawn by alternating violet and blue colors in the upper part are Bohmian trajectories divergent from the slits to infinity. 9 v$_{x}$ = ˙ x = ∇ S m = ¯ h m ℑ ( | Ψ 〉 − $^{1}$∇ | Ψ 〉 ) . (31)        x ( t ) = x$_{0}$ + t ∫ 0 v$_{x}$ dτ, z ( t ) = z$_{0}$ + v$_{z}$t. (32) z$_{T}$ 2z$_{T}$ 3z$_{T}$ 4z$_{T}$ d d d d d d z$_{T}$ = 2 d 2 λ (33)