Backscattering vs scattering

[nicodemoor]

Hello,

I've found something weird when I compare the backscattering efficiency and the scattering efficiency of gold particle (50nm=R).

The former is higher than the last which I think could not be possible!

What's wrong?

Here the code :

`
import PyMieScatt as ps
from Mie2 import Miedata
import matplotlib.pyplot as plt
from numpy import array
md = Miedata("Au")

wvl,n,k = md.indice()

m = n + k*1j

Qext_list = []
Qsca_list = []
Qabs_list = []
g_list = []
Qpr_list = []
Qback_list = []
Qratio_list = []

print(len(wvl))

for i in range(len(wvl)):
[Qext,Qsca,Qabs,g,Qpr,Qback,Qratio] = ps.AutoMieQ(m[i],wvl[i],50,1.33,asCrossSection=False)

Qext_list.append(Qext)
Qsca_list.append(Qsca)
Qabs_list.append(Qabs)
g_list.append(g)
Qpr_list.append(Qpr)
Qback_list.append(Qback)
Qratio_list.append(Qratio)

plt.plot(wvl,Qratio_list,label="Qratio")
plt.plot(wvl,array(Qback_list)/array(Qsca_list),"--",label="calculate")
plt.plot(wvl,Qback_list,label="Qback")
plt.plot(wvl,array(Qsca_list)array(Qratio_list),"--",label="QscaQratio")
plt.plot(wvl,array(Qsca_list),".",label="Qsca")
plt.ylabel("Q")
plt.xlabel("Wavelength (nm)")
plt.legend()
plt.show()

`

[isilber]

@nicodemoor, unless I missed something, the code appears solid to me. This apparent inconsistency results from a missing Qback normalization (1 / 4 * pi) to render it in proper units of m-1 sr-1. I therefore suspect that this issue could be closed.