This version, which has been integrated into the SPENVIS web-site, allows the user to execute Mulassis remotely
without the need to install Geant4 and the
Mulassis code on his/her local computer. However, users preferring a local version of this tool can download the
source code from the
websites. In addition, a stand-alone executable for Linux systems is available from the
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
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 Mulassis run exceeds
this limit, the simulation will be terminated and intermediate results returned to the user.
The default geometry is a single planar slab geometry with 26
layers (the boundaries are equivalent to the default SHIELDOSE
thicknesses, but the geometry as a whole isn't). The material for the default
geometry is Aluminium.
When a user defined geometry is chosen, the page includes a table with the
choice of a planar
geometry, and the number of layers to use. The next lines of the table are
created dynamically, depending on the number of layers.
For each layer, the user can define the material to use, the thickness (with
units), and the
colour to use in the graphical representation. For the material, there are four
defaults defined: Vacuum, Air, Aluminium and Silicon. Pressing the
button in the header of the table opens the
material definition page and allows the user to choose other
materials or define new materials.
The next option is to get some graphical representation of the chosen geometry.
This can be made in two formats, i.e. PostScript or VRML (available only if
number of layers is less than ten), 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.
Users can employ the material definition tool to
either specify their own material or make use of the predefined lists.
More specifically in Mulassis, advanced users can group the shield layers into different regions
and apply different cuts to each region. It can be a single cut for gamma, electron and positron productions, or different cuts for each type of the three particles.
The user can make only one analysis at a time. For more analyses new runs are
The report file spenvis_mlr.txt contains details of the
inputs and outputs.
The log file spenvis_mlp.txt records the output from
Mulassis to stdout and stderr.
The output file spenvis_mlo.txt containing tabulated
results (fluence, NID, dose or PHS) for the selected analysis.
The graphics files spenvis_ml.wrl and
spenvis_ml.eps show the 3D geometry or the shield
To generate plots, select the plot
type(s), options and
and click the button.
The current page will be updated with the newly generated plot files.