Simple example

target	water
excitation energy	59.54 keV (Am241 main gamma-line)
azimuthal angle	0°
scattering angle	90°
number of collisions considered	4
number of photons	1000000
transport model	vector

Part A - RESOLUTION

The user has to enter a real value for the maximum for the energy in keV (in this case 60). Then, the code needs another real number to define the resolution of the channels in keV (in the example we use the default value 0.1).

After reading these values, the program shows a summary of the energy resolution.

Part B - TARGET, SOURCE and GEOMETRY

The user has to enter a string with the name of the target. In the next step, the code asks to specify how to get the sample composition:

It is assumed that the user have already edited a file with the name SAMPLE.DAT, located in the directory TARGETS/targetname (where targetname is the string entered before, in this case H2O) and with the characteristics explained in the page input of the code.

The user can load a file containing all the information needed by the code (as explained in the page input of the code). In this example, the file SOURCES/AM241_203.DAT was selected.

The user can load a file containing all the information needed by the code (as explained in the page input of the code). In this example, the file GEOMETRY/GEO4545_203.DAT was selected.

Once selected, the single configuration files can be inspected using the corresponding button VIEW.

Part C - COLLISIONS

The code needs two integer numbers: the maximum number of collisions considered, and the number of hystories (i.e. the number of photons) to simulate.

Part D - TRANSPORT MODEL

The code needs to select a vector or scalar transport model. Vector means full description of the polarization state using the Boltzmann vector equation. Scalar means traditional MC considering an average unpolarised state.

NORMAL EXECUTION

When all the necessary information to perform a simulation has been input, the START button becomes visible and can be pressed to start normal execution.

After reading the file SAMPLE.DAT, the code writes on the file mcshape.log some information about the elements of every layer of the target: chemical symbol, density [g/cm^3], atomic number, atomic weight, weight fraction of the element in the layer and electronic characteristics. In this example, the electronic shells considered are zero both for Hydrogen and for Oxigen. Important: no electronic shells considered means no photoelectric effect: for a target of water the only interaction considered are Rayleigh and Compton scattering.  

NORMAL TERMINATION

The code prints some information about the correct end of the simulation in the window console and in the file run.log. A normal termination dialog appears:

All the output files are placed in the directory TARGET/targetname/RES. If this folders does not exist, the program creates it The code always overwrites the files in it.

At termination there become active three new buttons: View run.log, View mcshape.log and Plots which make rapidly accesible information about the run, and the results.

Output

After the execution of MCSHAPE, in the directory TARGETS\H2O\RES you can find the following files

1) Text files

SPECTRUM.DAT	file containing the full energy spectrum
SPECTRUM_W.DAT	file with the intensity corrected considering the width of the characteristic lines
CONTINUUM.DAT	file with the continuous part of the spectrum
DISCRETE.DAT	file with the discrete part of the spectrum
PHOTO_EFFECT.DAT	file containing the spectrum of the chains with at least one photoelectric collision
ONLY_COMPTON.DAT	file containing the intensity due to Compton scattering only
ONLY_SCATTERING.DAT	file with the intensity due to pure scattering, i.e. without any photoelectric collision
ONLY_PHOTO.DAT	file containing the intensity due to pure photoelectric effect
ONLY_PHOTO_W.DAT	file containing the intensity due to pure photoelectric effect corrected considering the width of the characteristic lines
TR_BEAM.DAT	file containing the intensity of the uncollided transmitted beam
STOKES1.DAT	file with the intensity component in function of the energy
STOKES2.DAT	file with the second component of the Stokes vector
STOKES3.DAT	file with the third component of the Stokes vector
STOKES4.DAT	file with the fourth component of the Stokes vector
ANGLE_CHI.DAT	file with the angle chi as a function of the energy
POL_DEGREE.DAT	file with the polarization degree of the spectrum as a function of the energy
mcshape.log	file with some infomation about the simulation
run.log	file with information about the run state.

The graphic view of this information can be obtained using the Plots button.

©Copyright 2006
ALMA MATER STUDIORUM - Università  di Bologna
Via Zamboni, 33 - I-40126 Bologna