RadiationMapsMaker: added maps of mass fractions for all natural elements

each grid point will collect the density- and step-length-weighted mass-fraction of the encountered elements. This gives the effective atomic composition of materials in each grid point. The first and last element to track is configurable - by default all natural elements ( 1 <= Z <= 92 ) are enabled. Example output in the service area of LAr from a geantino scan in the barrel: H: 0.00525763 C: 0.162227 N: 0.0470331 O: 0.0583856 F: 0.0808482 Si: 0.000496895 Ar: 0.000285226 Mn: 0.000496895 Fe: 0.0486957 Cu: 0.596274

Simulation/G4Utilities/G4UserActions/G4UserActions/RadiationMapsMaker.h

 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef G4UserActions_RadiationMapsMaker_H
@@ -66,6 +66,10 @@ namespace G4UA
 	int nBinslogT   =  20;   
 	double logTMin  = -9.; // log10(t_cut/s); first bin for t < 1 ns 
 	double logTMax  = 11.; // log10(t_cut/s); last bin for t < 3169 a
+
+	// elements mass fraction maps
+	int elemZMin    =   1; // minimum Z to keep mass fraction
+	int elemZMax    =  92; // maximum Z to keep mass fraction
       };
 
 
@@ -190,6 +194,13 @@ namespace G4UA
 	/// vector of time dependent TID in full 2d grid 
 	std::vector<double> m_full_rz_tid_time;
 
+	// maps of element fractions 
+
+	/// vector of element fractions in zoom 2d grid 
+	std::vector<double> m_rz_element;
+	/// vector of element fractions in full 2d grid 
+	std::vector<double> m_full_rz_element;
+
 	void merge(const Report& maps);
       };