MASK is capable of simulating multi-step kinematic reaction-decay sequences, storing data in ROOT Trees, after which the kinematic data can be fed to a detector geometry for efficiency testing. Currently geometries for ANASEN and SABRE are included in the code.
By default MASK is capable of simulating reactions of up to three steps. Here is a brief outline of each type:
0. A reaction of type 0 is a pure decay. It is assumed isotropic by default; any other case will require the modification of the code.
1. A reaction of type 1 is a pure reaction. It can incorporate all of the input file sampling parameters.
2. A reaction of type 2 is a reaction followed by a subsequent decay of the residual nucleus. Again, all sampling is allowed.
3. A reaction of type 3 is a reaction followed by a subsequent decay of the residual, followed by a decay of one of the products. Again, all sampling is allowed
For decays, a specific angular distribution can be given as input as a text file with values of coefficiencts of a Legendre polynomial series. Examples can be found in the `./etc` directory, including an isotropic case. It is assumed that the decays in the center-of-mass frame are isotropic in phi (i.e. m=0). Decay1 corresponds to the first decay, if there are multiple steps, Decay2 to the second. If there are no decays, these parameters are not used (or if only one decay, Decay2_AngularMomentum is not used). The input file requires that the user include target information, which will be used to calculate energy loss for all of the reactants and reaction products. The energy loss through materials is calculated using the `catima` library (found in `src/vendor`), which is a C/C++ interface to the `atima` library (the same energy loss methods used by LISE). The target can contain layers, and each layer can be composed of a compound of elements with a given stoichiometry. If the user wishes to not include energy loss in the kinematics, simply give all target layers a thickness of 0. Note that more layers and more thickness = more time spent calculating energy loss. These energy loss methods are only applicable for solid targets, and should not be applied to gas or liquid targets. Energy loss calculations have a stated uncertainty of approximately five percent.
To choose which detector scheme is run, modify the main function in DetectorEfficiency.cpp. The included geometries also have options to do an internal geometry consistency check and print out coordinates for drawing the detector arrays.
where the detection datafile contains all of the kinematics data as well as information about which particles are detected and the statsfile is a text file containing efficiency statistics.
