A typical choice for the impact parameter is the " y "-coordinate, while the trajectory angle is kept constant at zero degrees horizontal.
12.
At low energies the channelling effects in crystals are not present because small-angle scattering at low energies requires large impact parameters, which become bigger than interplanar distances.
13.
At large impact parameters, the charge of the ion is shielded by the tendency of electrons to cluster in the neighborhood of the ion and other ions to avoid it.
14.
The minimum distance " b " is the impact parameter, which is defined as the length of the perpendicular from the fixed center to the line of motion.
15.
R and r are the radii of the scattering center and scattered sphere, respectively, b the impact parameter and \ vartheta the polar angle of the exit trajectory as above.
16.
The differential cross section is always taken to be positive, even though in the most frequent case of limited-range repulsive interactions, larger impact parameters tend to cause less deflection.
17.
These are collisions in which the colliding nuclei do not touch each other; i . e ., the impact parameter b is larger than the sum of the radii of the nuclei.
18.
Setting the above estimate for \ Delta m _ e v _ \ perp equal to " mv ", we find the lower cut-off to the impact parameter to be about
19.
In passing through a field of ions with density " n ", an electron will have many such encounters simultaneously, with various impact parameters ( distance to the ion ) and directions.
20.
Often called the impact parameter, this is important in physics and astronomy, and measure the distance a particle will miss the focus by if its journey is unperturbed by the body at the focus.
