RayleighMC

Author: Miao Yu -> miaoyu@whu.edu.cn

MC program for angular / polarisation simulation of Rayleigh scattered photons of anisotropic molecules.

Python scripts have been implemented and validated for toy study and algorithm development.

A simple Geant4 package has been implemented in dir "./Ray".

Implementations:

PYTHON: - Rayleigh_class : a class describing Rayleigh scattering for single photon.

- Polarisation and momentum of the incident photon need to be specified. 

- Depolarization ratio is required as a material property for calculation.

- Functions: 

  1) calculatePol / calculatePol_modified: given certain scattering direction before, calculate polarization of scattered photons.

  2) sampleMomPol / sampleMomPol_modified: sample momentum and polarization of scattered photons.

• detector: describing the physical properties of an ideal detector. The most important one is the detection polarisation direction by using "set_detPol()".

GEANT4:

Geant4 codes are implemented in dir "G4Test/" where a Geant4.10.04 version software has been used.

• geometry: a simple sample was placed at center with customed Rayleigh scattering length (RAYLEIGH) and penpendicularly polarized depolarization ratio (RHOV); A 4Pi sensitive detector surrounds the sample outside to detect photons and give the angular/polarization information.
• Optical process: a customed RayleighScattering class has been implemented to sample scattered photons for anisotropic liquids. (MatrixCalc class has been added for matrix and vector calcualtion in new class);
• analyser: save root files of simulation fo analysis.

Tools for matrix calculation:

• vector_method.py : return perpendicular vector
• calculateRotationMatrix.py : some matrix calculation

Usage:

• example1.py : for isotropic molecules. Detect scatterred light at certain direction with polariser.
• example2.py : for anisotropic molecules. Detect scatterred light at certain direction with polariser. Validate Hh angular distribution.
• example3.py : at Phi=270 deg, check if the rho_v == Hv/Vv for different input rhov.
• example4.py : compare MC sim and measurement data.
• example5.py : sample scattered photons of anisotropic liquids.

For Geant4 codes, entering Ray/build, using "./exampleRay photon.mac" to generate events and get output root file for analysis.