- #1

- 25

- 0

*relative*permittivity (dielectric constant/function). it is known that [tex]n = \sqrt{\epsilon_r}[/tex] for optical frequencies (i.e. [tex]\mu_r=1[/tex].

now this website

http://hyperphysics.phy-astr.gsu.edu/Hbase/tables/diel.html#c1

gives the

*relative*permittivity of water as 80.4 i.e. [tex]\epsilon_r = 80.4[/tex]

but we also know that the index of refraction of water is 1.33.

so it should be [tex]n = \sqrt{\epsilon_r} = \sqrt{80.4} = 8.9666[/tex] ??? am i missing something here?

i want to use the

*relative*permittivity in an equation to calculate the electrostatic approximation of the scattering/absorption efficiencies of small spherical particles.

should i be solving for

*relative*permittivity from the index of refraction? i.e. [tex]{n}^{2} = {(\sqrt{\epsilon_r})}^{2} \Rightarrow \epsilon_r={1.33}^{2}=1.7689[/tex]

what value should i use for the

*relative*permittivity in this equation?

thanks guys.