BRAhms Geant - VMC version 2.0 Introduction. This is a simulation of the BRAHMS (Broad RAnge Hadron Magnetic Spectrometer) at the RHIC (Relativisitic Heavy Ion Collider) at BNL (Brookhaven National Laboratory), New York, USA. It uses the Virtual Montecarlo interface of ROOT, as well as the third-party class libraries Framework and Simulation. Any transport code supported by the ROOT VMC can be used. That current includes GEANT 3.21, GEANT 4, and FLUKA. Getting started. Compile the code first. Note that you need ROOT, Framework and Simulation. > ./configure > make Next, you need some VMC. Take for example GEANT 3.21, and compile and install it. Now, try to run it. > root -l scripts/Config.C This will load in the library, and set up as defined in the configuration. You can now trigger single particles by selecting Trigger in the Brag context menu. See also the documentation of the Simulation framework for more information and options.