What is TPDSci | Contact Support TPDSci Project

 Topics in Particle and Dispersion Science

  Home | Survey | Topics | Index | References | Dictionary | Contribute | Gallery | Community | Search

Entire site Survey Topics Index References

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

• rcb
• relative particle size
• RF
• RGD
• ROPI
• RTE
• RTM

RGD - Rayleigh-Gans-Debye light scattering model, also known as the Born approximation (for example, Sharma SK and Sommerford 2006 p. 12). The origin of the RGD abbreviation and its variations are discussed, for example, by Bohren CF and Huffman 1983, pp. 158-159. This model applies to small and optically "tenuous", or "soft" particles, i.e. particles that do not appreciably perturb the incident light wave. Hence, it requires that the relative size, x, and refractive index, m, of the particle relative to that of the surrounding medium fulfill the following inequalities (for example, Bohren CF and Huffman 1983, p. 159)

| m - 1 | << 1	(1)
2 x| m - 1 | << 1	(2)

The RGD model is discussed, for example, in Bohren CF and Huffman 1983, p. 158. Kerker M et al 1963 evaluated the error of this model for spheres as a function of the scattering angle, relative particle size and refractive index. This model is surprisingly flexible, as it provides reasonable qualitative results for particles well outside its applicability range (for example, Hirsch E et al 1994). See also Rayleigh-Gans-Debye model of scattering in the index. [MJ]