Users can go to any particular input page and enter their settings. After they are done, they can hit the button and return to the main model page. Once they are satisfied with all their input they can use the button to generate the macro file. Pressing the button will start the calculation and bring up the results page.
As the model uses a Monte-Carlo simulation-based code, execution times can be very long. In order to guarantee the consistency between the different models available in the SPENVIS system (e.g. particle spectrum vs. total ionising dose), the user project is 'blocked' while running the multi-layered shielding simulation, but navigation remains possible. The excution is limited to ten minutes of CPU-time on the simulation machine. If the GEMAT run exceeds this limit, the simulation will be terminated and intermediate results returned to the user.
All layers have the same surface dimensions. By default, the dimension of the layers is 10 times the total thickness of the layers, but this can be overridden. For each layer, the user can define the layer material, the thickness and the colour to use in the graphical representation. For the material selection, four default materials are available: vacuum, air, aluminium and silicon. In addition, pressing the button in the header of the table opens the material definition page where other materials can be selected or defined.
The next option is to get a VRML graphical representation of the chosen geometry (with or without particle tracks). Note that no particle tracks would be represented in the graphics file if more than hundred primary particles are requested for the simulation.
The following shapes are available for the contact and depletion volumes: cylinder, box, L shape and U shape. Each volume is defined in terms of a volume material, the layer in which it is positioned, a colour for the graphical representation, two position coordinates, a number of dimensions (dependent on the shape of the volume), and the units for the position and size parameters. Contact volumes are defined as follows:
Users can employ the material definition tool to either specify their own material or make use of the predefined lists.
In GEMAT, the depletion volumes have been grouped into one single region, and different cuts can be applied to this region. Advanced users can specify a single cut for gamma, electron and positron productions, or different cuts for each type of the three particles.
The user can specify the particle type to be included in the fluence analysis: protons, neutrons, electrons, gamma rays and charged pions. An option is available to select the incident particle type. Multiple selections are allowed. At least one particle type has to be selected.
The spectrum binning scheme can be defined by the user:
The report file spenvis_ger.txt contains details of the inputs and outputs. The log file spenvis_gep.txt records the output from GEMAT to stdout and stderr. The output file spenvis_geo.txt contains tabulated results (fluences, pulse height spectra, path length distributions, coincidence rates) for the various analysis types. The graphics file spenvis_gem.wrl shows the 3D geometry. Output files generated by GEMAT File name Description spenvis_ger.txt Report file spenvis_gep.txt Log file spenvis_geo.txt Outputs for the various analysis type spenvis_gem.wrl VRML representation of the geometry To generate plots, select the plot type(s), options and graphics format, and click the button. The current page will be updated with the newly generated plot files. References REAT website Geant4 website Geant4 Physics Reference Manual Last update: Mon, 12 Mar 2018
spenvis_ger.txt
spenvis_gep.txt
spenvis_geo.txt
spenvis_gem.wrl
To generate plots, select the plot type(s), options and graphics format, and click the button. The current page will be updated with the newly generated plot files.