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Version: SMASH-2.0
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Version: SMASH-2.0
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To produce a certain output content it is necessary to explicitly configure it in the Output section of the configuration file. This means, that the Output section needs to contain a subsection for the desired output. Aditionally, there are general output configuration parameters.
Output_Interval (double, optional, default = End_Time):
Defines the period of intermediate output of the status of the simulated system in Standard Output and other output formats which support this functionality.
Output_Times (doubles, optional, no default):
Explicitly defines the the times where output is generated in the form of a list. Cannot be used in combination with Output_Interval. Output times outside the simulation time are ignored. The following example will produce output at event start, event end and at the specified times as long as they are within the simulation time.
Output:
Output_Times: [-0.1, 0.0, 1.0, 2.0, 10.0]
Density_Type (string, optional, default = "none"):
Determines which kind of density is printed into the headers of the collision files. Possible values:
"hadron" - Total hadronic density "baryon" - Net baryon density "baryonic isospin" - Baryonic isospin density "pion" - Pion density "none" - Do not calculate density, print 0.0
Further options are defined for every single output content (see output contents for the list of possible contents). Independently of the content, it is always necessary to provide the format in which the output should be generated.
Format (list of formats, optional, default = [ ]):
List of formats for writing particular content. Possible formats for every content are listed and described in output contents. List of available formats is here.
Besides the universal Format option, there are also content-specific output options that are listed below.
Extended (bool, optional, default = false, incompatible with Oscar1999, VTK and Root formats): true - Print extended information for each particle false - Regular output for each particleOnly_Final (string, optional, default = Yes, incompatible with VTK format): Yes - Print only final particle list IfNotEmpty - Print only final particle list, but only if event is not empty (i.e. any collisions happened between projectile and target). Useful to save disk space. No - Particle list at output interval including initial time Extended (bool, optional, default = false, incompatible with Oscar1999 and Root formats): true - Print extended information for each particle false - Regular output for each particlePrint_Start_End (bool, optional, default = false, incompatible with Root format): true - Initial and final particle list is printed out false - Initial and final particle list is not printed out Extended (bool, optional, default = false, incompatible with Oscar1999 format): true - Print extended information for each particle false - Regular output for each particle Extended (bool, optional, default = false, incompatible with Oscar1999 format): true - Print extended information for each particle false - Regular output for each particle Proper_Time (double, optional, default = nuclei passing time, if nuclei passing time > Lower_Bound, else Lower_Bound): Proper time at which hypersurface is created Lower_Bound (double, optional, default = 0.5 fm): Lower bound for the IC proper time if Proper_Time is not provided.Extended (bool, optional, default = false, incompatible with Oscar1999, ROOT and ASCII format):true - Print extended information for each particle false - Regular output for each particle Thermodynamics
The user can print thermodynamical quantities:
Type (string, optional, default = "baryon"):
Particle type taken into consideration, "baryon" corresponds to "net
baryon".
"hadron" "baryon" "baryonic isospin" "pion" "none" "total isospin" Quantities (list of thermodynamic quantities, optional, default = [ ]):
List of thermodynamic quantities that are printed to the output. Possible quantities are:
"rho_eckart" - Eckart rest frame density "tmn" - Energy-momentum tensor \(T^{\mu\nu}(t,x,y,z) \) "tmn_landau" - Energy-momentum tensor in the Landau rest frame. This tensor is computed by boosting \(T^{\mu\nu}(t,x,y,z) \) to the local rest frame, where \(T^{0i} \) = 0. "landau_velocity" - Velocity of the Landau rest frame. The velocity is obtained from the energy-momentum tensor \(T^{\mu\nu}(t,x,y,z) \) by solving the generalized eigenvalue equation \((T^{\mu\nu} - \lambda g^{\mu\nu})u_{\mu}=0 \). "j_QBS" - Electric (Q), baryonic (B) and strange (S) currents \(j^{\mu}_{QBS}(t,x,y,z) \); note that all currents are given in units of "number of charges"; multiply the electric current by the elementary charge \(\sqrt{4 \pi \alpha_{EM}} \) for charge units.Position (list of 3 doubles, optional, default = [0.0, 0.0, 0.0]):
Point, at which thermodynamic quantities are computed.
Smearing (bool, optional, default = true):
Using Gaussian smearing for computing thermodynamic quantities or not. This triggers whether thermodynamic quantities are evaluated at a fixed point (true) or summed over all particles (false).
true - smearing applied false - smearing not appliedThe contribution to the energy-momentum tensor and current (be it electric, baryonic or strange) from a single particle in its rest frame is:
\[\begin{eqnarray} j^{\mu} = B \frac{p_0^{\mu}}{p_0^0} W \\ T^{\mu \nu} = \frac{p_0^{\mu}p_0^{\nu}}{p_0^0} W \end{eqnarray}\]
with B being the charge of interest and W being the weight given to this particle. Normally, if one computes thermodynamic quantities at a point, smearing should be applied, and then W takes on the following shape:
\[W = (2 \pi \sigma^2)^{-3/2} exp \left(- \frac{(\mathbf{r} - \mathbf{r_0(t)})^2}{2\sigma^2} \right)\]
It can however be useful to compute the thermo- dynamic quantities of all particles in a box with W = 1, which would correspond to "Smearing: false". Note that using this option changes the units of the thermodynamic quantities, as they are no longer spatially normalized. One should divide this quantity by by the volume of the box to restore units to the correct ones.