As discussed above, for the effective elastic scattering, the

scattering angles are modest and the scattered particles tend to hit the detector, so FFD is not required.

In SANS, a beam of neutrons is focused on a sample and the neutrons that are scattered at small

scattering angles are detected on a two-dimensional (2D) detector.

The matter is that the structure of the collision integral implies division of its kernel onto three parts related to hard (hard collisions are mainly large-angle scattering collisions [9] that lead to establishing the equilibrium distribution of molecules over velocities after each collision, soft collisions are caused by classical scattering on small angles less 0.3 rad [10], and the diffraction-scattering collisions occur when

scattering angles are ~0.01 rad [8-10].), soft, and diffraction-scattering collisions [7-11].

The

scattering angles work with [theta] varies from 0[degrees] to 360[degrees] and [phi] = 0[degrees].

Bistatic scattering patterns for the scattering coefficient y (magnitude) as a function of the

scattering angles [[theta].sub.2] and [[theta].sub.3] of Fig.

The incident and

scattering angles are set by [[theta].sub.s] = [[theta].sub.i], [[phi].sub.s] = [[phi].sub.i] = 90[degrees].

For bistatic case, the average NRCS versus

scattering angles for incidence angles of 0[degrees] and 45[degrees] are shown in Figure 4.

For

scattering angles below [approximately equal to]17[degrees] the analyzer system moves behind the beam stop.

To ascertain the validity of Guinier's approximation to the EVA nanocomposites, it is imperative that two conditions be satisfied: (a) There is a linear fit between In [I(q)] and [q.sup.2] at low q, corresponding to small

scattering angles; (b) q[R.sub.g] < 1.

Figure 1 presents the optical geometry, where [[theta].sub.o] and [[theta].sub.s] are the incidence and

scattering angles measured with respect to the normal of the specimen.

With essentially 1.3 million detector elements collecting light scattering data for each of several exposures as it steps through the range of

scattering angles, the instrument delivers unprecedented detail required for serious research projects.