diff --git a/CMakeLists.txt b/CMakeLists.txt
index bfd56990a..94e03ca7c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,46 +1,29 @@
-set( LibraryVersion "1.6" )
+set(LibraryVersion "1.6")
 add_definitions(-DLIBRARY_VERSION="${LibraryVersion}")
 
-#find garfield libs and includes
-IF (NOT DEFINED REST_GARFIELD)
+if (NOT DEFINED REST_GARFIELD OR NOT REST_GARFIELD)
     set(REST_GARFIELD OFF)
-ENDIF ()
-
-if (${REST_GARFIELD} MATCHES "ON")
-    add_definitions(-DUSE_Garfield)
-
-    if (DEFINED ENV{GARFIELD_INSTALL})
-        # Tested for Garfield af4a14516489babbd6e6df780edd58fedf7fa12b
-        message(STATUS "Using new Garfield CMake")
-        set(GARFIELD_INSTALL $ENV{GARFIELD_INSTALL})
-        find_package(Garfield REQUIRED)
-        set(external_include_dirs ${external_include_dirs} ${GARFIELD_INSTALL}/include/Garfield)
-        set(external_libs ${external_libs} Garfield::Garfield)
-        # recommended CMake way does not work, we need to delete the "FindGarfield.cmake" script
-    elseif (DEFINED ENV{GARFIELD_HOME})
-        # Old way, for backwards compatibility
-        message(STATUS "Using old Garfield CMake")
-        set(GARFIELD_INSTALL $ENV{GARFIELD_HOME})
-        include(FindGarfieldOld)
-        message(STATUS Garfield_INCLUDE_DIRS ${Garfield_INCLUDE_DIRS})
-        message(STATUS Garfield_INCLUDE_DIRS ${Garfield_INCLUDE_Heed_DIRS})
-        message(STATUS Garfield_LIBRARIES ${Garfield_LIBRARIES})
-        set(external_include_dirs ${external_include_dirs} ${Garfield_INCLUDE_DIRS})
-        set(external_include_dirs ${external_include_dirs} ${Garfield_INCLUDE_Heed_DIRS})
-        set(external_libs ${external_libs} ${Garfield_LIBRARIES})
-        add_definitions(-DUSE_Garfield_OLD)
-    else ()
-        message(FATAL_ERROR "Garfield not found")
-    endif ()
-
-    #set(GARFIELD_INSTALL $ENV{GARFIELD_INSTALL})
-    message(STATUS "GARFIELD INSTALLATION: ${GARFIELD_INSTALL}")
+    message(STATUS "Garfield DISABLED")
+endif ()
+
+if (REST_GARFIELD)
+    message(STATUS "Garfield ENABLED")
+
+    add_compile_definitions(REST_GARFIELD)
+
+    # Tested for Garfield af4a14516489babbd6e6df780edd58fedf7fa12b
+    find_package(Garfield REQUIRED)
+
+    set(GARFIELD_INSTALL $ENV{GARFIELD_INSTALL})
+    set(external_include_dirs ${external_include_dirs} ${GARFIELD_INSTALL}/include/Garfield)
+    set(external_libs ${external_libs} Garfield::Garfield)
+
+    message(STATUS "GARFIELD installation found at ${GARFIELD_INSTALL}")
 
     set(feature_added "Garfield")
     set(feature_added ${feature_added} PARENT_SCOPE)
-else ()
-    set(REST_GARFIELD OFF)
-endif (${REST_GARFIELD} MATCHES "ON")
+
+endif ()
 
 if (NOT ${REST_EVE} MATCHES "ON")
     set(excludes ${excludes} TRestDetectorHitsEventViewer)
diff --git a/inc/TRestDetector.h b/inc/TRestDetector.h
index 958ad36a2..9ece96beb 100644
--- a/inc/TRestDetector.h
+++ b/inc/TRestDetector.h
@@ -40,13 +40,11 @@
 #include "TRestStringOutput.h"
 #include "TRestTools.h"
 
-using namespace std;
-
 //! An metadata class to store basic detector information
 class TRestDetector : public TRestMetadata {
    public:
     /// The detector name
-    string fDetectorName = "REST Detector";
+    std::string fDetectorName = "REST Detector";
 
     /// The detector drift voltage in V
     Double_t fDriftVoltage = -1;
@@ -84,11 +82,11 @@ class TRestDetector : public TRestMetadata {
     Double_t fElectronicsThreshold = -1;
 
     /// The electronics gain in raw configuration format (hexadecimal)
-    string fElectronicsGain = "-1";
+    std::string fElectronicsGain = "-1";
     /// The electronics clock (sampling) in raw configuration format (hexadecimal)
-    string fElectronicsClock = "-1";
+    std::string fElectronicsClock = "-1";
     /// The electronics shaping in raw configuration format (hexadecimal)
-    string fElectronicsShaping = "-1";
+    std::string fElectronicsShaping = "-1";
 
     void InitFromConfigFile() { ReadAllParameters(); }
 
@@ -96,7 +94,7 @@ class TRestDetector : public TRestMetadata {
 
     void UpdateMetadataMembers();
 
-    // Constructors
+    // Constructor
     TRestDetector() {}
     // Destructor
     ~TRestDetector() {}
diff --git a/inc/TRestDetectorDaqChannelSwitchingProcess.h b/inc/TRestDetectorDaqChannelSwitchingProcess.h
index 05e449bb6..4a78157b9 100644
--- a/inc/TRestDetectorDaqChannelSwitchingProcess.h
+++ b/inc/TRestDetectorDaqChannelSwitchingProcess.h
@@ -13,9 +13,6 @@
 #define RestCore_TRestDetectorDaqChannelSwitchingProcess
 
 #include <TH1D.h>
-
-//#include <TCanvas.h>
-
 #include <TRestDetectorGas.h>
 #include <TRestDetectorHitsEvent.h>
 #include <TRestDetectorReadout.h>
diff --git a/inc/TRestDetectorGainMap.h b/inc/TRestDetectorGainMap.h
index 5c97d752f..3bfe9e326 100644
--- a/inc/TRestDetectorGainMap.h
+++ b/inc/TRestDetectorGainMap.h
@@ -48,16 +48,16 @@ class TRestDetectorReadout;
 class TRestDetectorGainMap : public TRestMetadata {
    public:
     bool relative;
-    map<int, double> fChannelGain;  // [channel id, gain]
-    TH2F* f2DGainMapping = 0;       //->
-    TH3F* f3DGainMapping = 0;       //->
+    std::map<int, double> fChannelGain;  // [channel id, gain]
+    TH2F* f2DGainMapping = nullptr;      //->
+    TH3F* f3DGainMapping = nullptr;      //->
 
     void InitFromConfigFile();
 
-    void SaveToText(string filename) {}
-    void ReadGainText(string filename) {}
+    void SaveToText(std::string filename) {}
+    void ReadGainText(std::string filename) {}
 
-    void DrawChannelGainMap(TRestDetectorReadoutModule* mod = 0);
+    void DrawChannelGainMap(TRestDetectorReadoutModule* mod = nullptr);
 
     ClassDef(TRestDetectorGainMap, 1);  // Gas Parameters
 };
diff --git a/inc/TRestDetectorGarfieldDriftProcess.h b/inc/TRestDetectorGarfieldDriftProcess.h
index 6c8cce099..b25c4ce4f 100644
--- a/inc/TRestDetectorGarfieldDriftProcess.h
+++ b/inc/TRestDetectorGarfieldDriftProcess.h
@@ -17,17 +17,11 @@
 
 #include <TRestDetectorGas.h>
 
-#if defined USE_Garfield_OLD
-#include "AvalancheMC.hh"
-#include "ComponentBase.hh"
-#include "Sensor.hh"
-typedef AvalancheMC DRIFT_METHOD;
-#elif USE_Garfield
+#if defined REST_GARFIELD
 #include "AvalancheMC.hh"
 #include "Component.hh"
 #include "Sensor.hh"
 typedef AvalancheMC DRIFT_METHOD;
-// TODO Could we have this as an option given through metadata?
 #endif
 
 #include <TRandom3.h>
@@ -47,7 +41,7 @@ class TRestDetectorGarfieldDriftProcess : public TRestEventProcess {
     TRestDetectorHitsEvent* fInputHitsEvent;   //!
     TRestDetectorHitsEvent* fOutputHitsEvent;  //!
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     TRestDetectorReadout* fReadout;    //!
     TRestDetectorGas* fGas;            //!
     TRestDetectorGeometry* fGeometry;  //!
@@ -61,9 +55,8 @@ class TRestDetectorGarfieldDriftProcess : public TRestEventProcess {
 
     Int_t FindModule(Int_t readoutPlane, Double_t x, Double_t y);
     Int_t FindChannel(Int_t module, Double_t x, Double_t y);
-#endif
+
    protected:
-#if defined USE_Garfield
     Double_t fGasPressure;     // atm
                                //         Double_t fElectricField; // V/cm
     Double_t fDriftPotential;  // V
@@ -79,7 +72,7 @@ class TRestDetectorGarfieldDriftProcess : public TRestEventProcess {
 
     TRestEvent* ProcessEvent(TRestEvent* eventInput);
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     void InitProcess();
     void EndProcess();
 
@@ -110,8 +103,7 @@ class TRestDetectorGarfieldDriftProcess : public TRestEventProcess {
     // Destructor
     ~TRestDetectorGarfieldDriftProcess();
 #endif
-    ClassDef(TRestDetectorGarfieldDriftProcess,
-             1);  // Template for a REST "event process" class inherited from
-                  // TRestEventProcess
+    ClassDef(TRestDetectorGarfieldDriftProcess, 1);
 };
+
 #endif
diff --git a/inc/TRestDetectorGas.h b/inc/TRestDetectorGas.h
index 44ad0a057..03777a4c0 100644
--- a/inc/TRestDetectorGas.h
+++ b/inc/TRestDetectorGas.h
@@ -22,6 +22,7 @@
 
 #ifndef RestCore_TRestDetectorGas
 #define RestCore_TRestDetectorGas
+
 #include <TROOT.h>
 
 #include <cstdlib>
@@ -40,14 +41,13 @@
 #include "TSystem.h"
 #include "TVector3.h"
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
 #include "ComponentConstant.hh"
 #include "GeometrySimple.hh"
 #include "MediumMagboltz.hh"
 #include "Sensor.hh"
 #include "SolidBox.hh"
 #include "TrackHeed.hh"
-using namespace Garfield;
 #else
 class MediumMagboltz;
 #endif
@@ -110,13 +110,13 @@ class TRestDetectorGas : public TRestDetectorDriftVolume {
     Bool_t fTest = false;  //!
 
     void InitFromConfigFile();
-    string ConstructFilename();
+    std::string ConstructFilename();
 
     void AddGasComponent(std::string gasName, Double_t fraction);
 
     void GenerateGasFile();
 
-    void UploadGasToServer(string gasFilename);
+    void UploadGasToServer(std::string gasFilename);
 
     Double_t GetDriftVelocity(Double_t E);
     Double_t GetLongitudinalDiffusion(Double_t E);
@@ -126,7 +126,7 @@ class TRestDetectorGas : public TRestDetectorDriftVolume {
 
    public:
     TRestDetectorGas();
-    TRestDetectorGas(const char* cfgFileName, string name = "", bool gasGeneration = false,
+    TRestDetectorGas(const char* cfgFileName, std::string name = "", bool gasGeneration = false,
                      bool test = false);
     ~TRestDetectorGas();
 
@@ -144,7 +144,7 @@ class TRestDetectorGas : public TRestDetectorDriftVolume {
 
     void LoadGasFile();
 
-    string FindGasFile(string name);
+    std::string FindGasFile(std::string name);
 
     void CalcGarField(double Emin, double Emax, int n);
 
@@ -162,8 +162,8 @@ class TRestDetectorGas : public TRestDetectorDriftVolume {
     /// Returns the gas component *n*.
     TString GetGasComponentName(Int_t n) {
         if (n >= GetNofGases()) {
-            cout << "REST WARNING. Gas name component n=" << n << " requested. But only " << GetNofGases()
-                 << " component(s) in the mixture." << endl;
+            std::cout << "REST WARNING. Gas name component n=" << n << " requested. But only "
+                      << GetNofGases() << " component(s) in the mixture." << std::endl;
             return "";
         }
         return fGasComponentName[n];
@@ -250,12 +250,12 @@ class TRestDetectorGas : public TRestDetectorDriftVolume {
     void PlotTransversalDiffusion(Double_t eMin, Double_t eMax, Int_t nSteps);
     void PlotTownsendCoefficient(Double_t eMin, Double_t eMax, Int_t nSteps);
     void PrintGasInfo();
-    void PrintGasFileContent() { cout << fGasFileContent << endl; };
+    void PrintGasFileContent() { std::cout << fGasFileContent << std::endl; };
 
     /// Prints the metadata information from the gas
     void PrintMetadata() { PrintGasInfo(); }
 
-    ClassDef(TRestDetectorGas, 3);  // Gas Parameters
+    ClassDef(TRestDetectorGas, 3);
 };
 
 #endif
diff --git a/inc/TRestDetectorGeometry.h b/inc/TRestDetectorGeometry.h
index d8ecefbd0..5e1909656 100644
--- a/inc/TRestDetectorGeometry.h
+++ b/inc/TRestDetectorGeometry.h
@@ -26,41 +26,27 @@
 
 #include "TRestDetectorGas.h"
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
 
-#if defined USE_Garfield_OLD
-#include "ComponentBase.hh"
-#else
-#include "Component.hh"
-#endif
-
-#include "GeometryRoot.hh"
-#include "Sensor.hh"
-
-#if defined USE_Garfield_OLD
-typedef Garfield::ComponentBase Component;
-#else
-typedef Garfield::Component Component;
-#endif
+#include <Component.hh>
+#include <GeometryRoot.hh>
+#include <Sensor.hh>
 
 #endif
 
-using namespace std;
-
 class TRestDetectorGeometry : public TGeoManager {
    protected:
-#if defined USE_Garfield
-    Garfield::GeometryRoot* fGfGeometry;  //!///< Pointer to Garfield::GeometryRoot object of the
-                                          //! geometry
-    vector<Component*> vGfComponent;      //!///< Vector of pointers to Garfield Component object
-    vector<Garfield::Sensor*> vGfSensor;  //!///< Vector of pointers to Garfield Sensor object
-    TGeoNode* fDriftElec;                 //!///< pointer to drift electrode
-    vector<TGeoNode*> vReadoutElec;       //!///< vector of pointers to readout planes
-
+#if defined REST_GARFIELD
+    Garfield::GeometryRoot* fGfGeometry =
+        nullptr;  //!///< Pointer to Garfield::GeometryRoot object of the geometry
+    std::vector<Garfield::Component*> vGfComponent;  //!///< Vector of pointers to Garfield Component object
+    std::vector<Garfield::Sensor*> vGfSensor;        //!///< Vector of pointers to Garfield Sensor object
+    TGeoNode* fDriftElec = nullptr;                  //!///< pointer to drift electrode
+    std::vector<TGeoNode*> vReadoutElec;             //!///< vector of pointers to readout planes
 #endif
 
    public:
-    // Construtor
+    // Constructor
     TRestDetectorGeometry();
     // Destructor
     virtual ~TRestDetectorGeometry();
@@ -68,8 +54,7 @@ class TRestDetectorGeometry : public TGeoManager {
     /// initialize Garfield::GeometryRoot geometry object
     void InitGfGeometry();
 
-#if defined USE_Garfield
-
+#if defined REST_GARFIELD
     /// Return pointer to Garfield::GeometryRoot geometry object
     Garfield::GeometryRoot* GetGfGeometry() { return fGfGeometry; }
 
@@ -79,7 +64,7 @@ class TRestDetectorGeometry : public TGeoManager {
     }
 
     /// Set Garfield field component
-    void AddGfComponent(Component* c) {
+    void AddGfComponent(Garfield::Component* c) {
         c->SetGeometry(fGfGeometry);
         vGfComponent.push_back(c);
     }
@@ -108,14 +93,14 @@ class TRestDetectorGeometry : public TGeoManager {
     }
 
     /// Get i^th Gf component
-    Component* GetGfComponent(unsigned int i) {
+    Garfield::Component* GetGfComponent(unsigned int i) {
         if (i < vGfComponent.size())
             return vGfComponent[i];
         else
             return nullptr;
     }
 
-    /// Getnumber of Gf components
+    /// Get number of Gf components
     int GetNbOfGfComponent() { return vGfComponent.size(); }
 
     /// Get i^th Gf sensor
@@ -126,7 +111,7 @@ class TRestDetectorGeometry : public TGeoManager {
             return nullptr;
     }
 
-    /// Getnumber of Gf sensors
+    /// Get number of Gf sensors
     int GetNbOfGfSensor() { return vGfSensor.size(); }
 
     /// Get Gf Medium at position
@@ -138,7 +123,7 @@ class TRestDetectorGeometry : public TGeoManager {
 
     void PrintGeometry();
 
-    ClassDef(TRestDetectorGeometry, 1);  // REST event superclass
+    ClassDef(TRestDetectorGeometry, 1);
 };
 
 #endif
diff --git a/inc/TRestDetectorHitsAnalysisProcess.h b/inc/TRestDetectorHitsAnalysisProcess.h
index e65ec6057..fbefda64b 100644
--- a/inc/TRestDetectorHitsAnalysisProcess.h
+++ b/inc/TRestDetectorHitsAnalysisProcess.h
@@ -23,10 +23,8 @@
 #ifndef RestCore_TRestDetectorHitsAnalysisProcess
 #define RestCore_TRestDetectorHitsAnalysisProcess
 
-#include <TH1D.h>
-
 #include <TCanvas.h>
-
+#include <TH1D.h>
 #include <TRestDetectorGas.h>
 #include <TRestDetectorHitsEvent.h>
 #include <TRestDetectorReadout.h>
diff --git a/inc/TRestDetectorHitsGaussAnalysisProcess.h b/inc/TRestDetectorHitsGaussAnalysisProcess.h
index f6640d5c5..d6c3ad0b6 100644
--- a/inc/TRestDetectorHitsGaussAnalysisProcess.h
+++ b/inc/TRestDetectorHitsGaussAnalysisProcess.h
@@ -23,10 +23,8 @@
 #ifndef RestCore_TRestDetectorHitsGaussAnalysisProcess
 #define RestCore_TRestDetectorHitsGaussAnalysisProcess
 
-#include <TH1D.h>
-
 #include <TCanvas.h>
-
+#include <TH1D.h>
 #include <TRestDetectorGas.h>
 #include <TRestDetectorHitsEvent.h>
 #include <TRestDetectorReadout.h>
diff --git a/src/TRestDetectorElectronDiffusionProcess.cxx b/src/TRestDetectorElectronDiffusionProcess.cxx
index 6afdc7af1..5fc7ce5d6 100644
--- a/src/TRestDetectorElectronDiffusionProcess.cxx
+++ b/src/TRestDetectorElectronDiffusionProcess.cxx
@@ -39,7 +39,6 @@ void TRestDetectorElectronDiffusionProcess::LoadDefaultConfig() {
     fGasPressure = 1;
 }
 
-//______________________________________________________________________________
 void TRestDetectorElectronDiffusionProcess::Initialize() {
     SetSectionName(this->ClassName());
     SetLibraryVersion(LIBRARY_VERSION);
@@ -65,7 +64,6 @@ void TRestDetectorElectronDiffusionProcess::LoadConfig(string cfgFilename, strin
     if (LoadConfigFromFile(cfgFilename, name)) LoadDefaultConfig();
 }
 
-//______________________________________________________________________________
 void TRestDetectorElectronDiffusionProcess::InitProcess() {
     fRandom = new TRandom3(fSeed);
 
@@ -86,7 +84,7 @@ void TRestDetectorElectronDiffusionProcess::InitProcess() {
             exit(-1);
         }
     } else {
-#ifndef USE_Garfield
+#ifndef REST_GARFIELD
         ferr << "A TRestDetectorGas definition was found but REST was not linked to Garfield libraries."
              << endl;
         ferr << "Please, remove the TRestDetectorGas definition, and add gas parameters inside the process "
@@ -114,7 +112,6 @@ void TRestDetectorElectronDiffusionProcess::InitProcess() {
     }
 }
 
-//______________________________________________________________________________
 TRestEvent* TRestDetectorElectronDiffusionProcess::ProcessEvent(TRestEvent* evInput) {
     fInputHitsEvent = (TRestDetectorHitsEvent*)evInput;
     fOutputHitsEvent->SetEventInfo(fInputHitsEvent);
@@ -222,7 +219,6 @@ TRestEvent* TRestDetectorElectronDiffusionProcess::ProcessEvent(TRestEvent* evIn
     return fOutputHitsEvent;
 }
 
-//______________________________________________________________________________
 void TRestDetectorElectronDiffusionProcess::EndProcess() {
     // Function to be executed once at the end of the process
     // (after all events have been processed)
@@ -232,7 +228,6 @@ void TRestDetectorElectronDiffusionProcess::EndProcess() {
     // TRestEventProcess::EndProcess();
 }
 
-//______________________________________________________________________________
 void TRestDetectorElectronDiffusionProcess::InitFromConfigFile() {
     fGasPressure = GetDblParameterWithUnits("gasPressure", -1.);
     fElectricField = GetDblParameterWithUnits("electricField", -1.);
@@ -242,7 +237,7 @@ void TRestDetectorElectronDiffusionProcess::InitFromConfigFile() {
     if (fLonglDiffCoeff == -1)
         fLonglDiffCoeff = StringToDouble(GetParameter("longDiff", "-1"));
     else {
-        warning << "longitudinalDiffusionCoeffient is now OBSOLETE! It will soon dissapear." << endl;
+        warning << "longitudinalDiffusionCoefficient is now OBSOLETE! It will soon disappear." << endl;
         warning << " Please use the shorter form of this parameter : longDiff" << endl;
     }
 
@@ -250,7 +245,7 @@ void TRestDetectorElectronDiffusionProcess::InitFromConfigFile() {
     if (fTransDiffCoeff == -1)
         fTransDiffCoeff = StringToDouble(GetParameter("transDiff", "-1"));
     else {
-        warning << "transversalDiffusionCoeffient is now OBSOLETE! It will soon dissapear." << endl;
+        warning << "transversalDiffusionCoefficient is now OBSOLETE! It will soon disappear." << endl;
         warning << " Please use the shorter form of this parameter : transDiff" << endl;
     }
     fMaxHits = StringToInteger(GetParameter("maxHits", "1000"));
diff --git a/src/TRestDetectorGarfieldDriftProcess.cxx b/src/TRestDetectorGarfieldDriftProcess.cxx
index bfc0dd394..570151b9c 100644
--- a/src/TRestDetectorGarfieldDriftProcess.cxx
+++ b/src/TRestDetectorGarfieldDriftProcess.cxx
@@ -14,12 +14,12 @@
 ///             march 2017:   Damien Neyret
 ///_______________________________________________________________________________
 
+#include "TRestDetectorGarfieldDriftProcess.h"
+
 #include <TGeoBBox.h>
 #include <TRandom3.h>
 
-#include "TRestDetectorGarfieldDriftProcess.h"
-
-#if defined USE_Garfield
+#if defined REST_GARFIELD
 #include "ComponentConstant.hh"
 #include "TGDMLParse.h"
 using namespace Garfield;
@@ -31,12 +31,10 @@ using namespace std;
 
 const double cmTomm = 10.;
 
-ClassImp(TRestDetectorGarfieldDriftProcess)
-//______________________________________________________________________________
-#if defined USE_Garfield
-    TRestDetectorGarfieldDriftProcess::TRestDetectorGarfieldDriftProcess()
-    : fRandom(0), fGfSensor(0) {
+ClassImp(TRestDetectorGarfieldDriftProcess);
 
+#if defined REST_GARFIELD
+TRestDetectorGarfieldDriftProcess::TRestDetectorGarfieldDriftProcess() : fRandom(0), fGfSensor(0) {
     Initialize();
 }
 
@@ -60,13 +58,10 @@ TRestDetectorGarfieldDriftProcess::TRestDetectorGarfieldDriftProcess(char* cfgFi
     // TRestDetectorGarfieldDriftProcess default constructor
 }
 
-//______________________________________________________________________________
-
-// TRestDetectorGarfieldDriftProcess destructor
 TRestDetectorGarfieldDriftProcess::~TRestDetectorGarfieldDriftProcess() {
-    if (fReadout != NULL) delete fReadout;
+    if (fReadout) delete fReadout;
     if (fGeometry) delete fGeometry;
-    fGeometry = NULL;
+    fGeometry = nullptr;
 
     delete fOutputHitsEvent;
 }
@@ -89,7 +84,6 @@ void TRestDetectorGarfieldDriftProcess::LoadConfig(string cfgFilename, string na
     }
 }
 
-//______________________________________________________________________________
 #endif
 
 void TRestDetectorGarfieldDriftProcess::Initialize() {
@@ -97,20 +91,19 @@ void TRestDetectorGarfieldDriftProcess::Initialize() {
     SetLibraryVersion(LIBRARY_VERSION);
 
     fRandom = new TRandom3(0);
-    fInputHitsEvent = NULL;
+    fInputHitsEvent = nullptr;
     fOutputHitsEvent = new TRestDetectorHitsEvent();
 
-#if defined USE_Garfield
-    fReadout = NULL;
-    fGas = NULL;
-    fGeometry = NULL;
+#if defined REST_GARFIELD
+    fReadout = nullptr;
+    fGas = nullptr;
+    fGeometry = nullptr;
     fPEReduction = 1.;
     fStopDistance = 2;  // default distance from readout to stop drift set to 2mm
 #endif
 }
 
-//______________________________________________________________________________
-#if defined USE_Garfield
+#if defined REST_GARFIELD
 void TRestDetectorGarfieldDriftProcess::InitProcess() {
     // Function to be executed once at the beginning of process
     // (before starting the process of the events)
@@ -344,7 +337,7 @@ Int_t TRestDetectorGarfieldDriftProcess::FindModule(Int_t readoutPlane, Double_t
 #endif
 
 TRestEvent* TRestDetectorGarfieldDriftProcess::ProcessEvent(TRestEvent* evInput) {
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     fInputHitsEvent = (TRestDetectorHitsEvent*)evInput;
 
     double x, y, z, energy;
@@ -440,9 +433,7 @@ TRestEvent* TRestDetectorGarfieldDriftProcess::ProcessEvent(TRestEvent* evInput)
 #endif
 }
 
-#if defined USE_Garfield
-
-//______________________________________________________________________________
+#if defined REST_GARFIELD
 
 void TRestDetectorGarfieldDriftProcess::EndProcess() {
     // Function to be executed once at the end of the process
@@ -453,8 +444,6 @@ void TRestDetectorGarfieldDriftProcess::EndProcess() {
     // TRestEventProcess::EndProcess();
 }
 
-//______________________________________________________________________________
-
 void TRestDetectorGarfieldDriftProcess::InitFromConfigFile() {
     fGasPressure = StringToDouble(GetParameter("gasPressure", "-1"));
     //     fElectricField = GetDblParameterWithUnits( "electricField" );
diff --git a/src/TRestDetectorGas.cxx b/src/TRestDetectorGas.cxx
index cae3f2e9d..793563dd9 100644
--- a/src/TRestDetectorGas.cxx
+++ b/src/TRestDetectorGas.cxx
@@ -254,7 +254,7 @@ TRestDetectorGas::TRestDetectorGas(const char* cfgFileName, string name, bool ga
 
     if (strcmp(cfgFileName, "server") == 0) {
         LoadConfigFromElement(StringToElement("<TRestDetectorGas name=\"" + name + "\" file=\"server\"/>"),
-                              NULL);
+                              nullptr);
     } else {
         fConfigFileName = cfgFileName;
         LoadConfigFromFile(fConfigFileName, name);
@@ -269,7 +269,7 @@ TRestDetectorGas::TRestDetectorGas(const char* cfgFileName, string name, bool ga
 TRestDetectorGas::~TRestDetectorGas() {
     debug << "Entering ... TRestDetectorGas() destructor." << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     delete fGasMedium;
 #endif
 }
@@ -297,10 +297,10 @@ void TRestDetectorGas::Initialize() {
     fGasFilename = "";
     fGasFileContent = "";
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     fGasMedium = new Garfield::MediumMagboltz();
 #else
-    fGasMedium = NULL;
+    fGasMedium = nullptr;
 #endif
 
     ///////////////////// ///////////////////// /////////////////////
@@ -326,7 +326,7 @@ void TRestDetectorGas::Initialize() {
 void TRestDetectorGas::LoadGasFile() {
     debug << "Entering ... TRestDetectorGas::LoadGasFile()." << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     debug << "fGasFilename = " << fGasFilename << endl;
     if (!TRestTools::fileExists((string)(fGasFilename))) {
         ferr << __PRETTY_FUNCTION__ << endl;
@@ -360,7 +360,7 @@ void TRestDetectorGas::CalcGarField(double Emin, double Emax, int n) {
     debug << "Entering ... TRestDetectorGas::CalcGarField( Emin=" << Emin << " , Emax=" << Emax << " )"
           << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     if (fEnodes <= 0) {
         cout << "REST ERROR : The number of nodes is not a positive number!!. Gas "
                 "file generation cancelled."
@@ -450,7 +450,7 @@ void TRestDetectorGas::AddGasComponent(string gasName, Double_t fraction) {
 // However, I tested with Xe+TMA and I got an error message that TMA
 // photoncrossection database is not available
 void TRestDetectorGas::GetGasWorkFunction() {
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     essential << __PRETTY_FUNCTION__ << endl;
     essential << "This method has never been validated to operate properly" << endl;
     essential << "If we manage to make it work we could use this method to "
@@ -520,7 +520,7 @@ void TRestDetectorGas::InitFromConfigFile() {
 
     // add gas component
     TiXmlElement* gasComponentDefinition = GetElement("gasComponent");
-    while (gasComponentDefinition != NULL) {
+    while (gasComponentDefinition) {
         string gasName = GetFieldValue("name", gasComponentDefinition);
         Double_t gasFraction = StringToDouble(GetFieldValue("fraction", gasComponentDefinition));
         AddGasComponent(gasName, gasFraction);
@@ -593,7 +593,7 @@ void TRestDetectorGas::InitFromConfigFile() {
     }
     fStatus = RESTGAS_CFG_LOADED;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     // calling garfield, either to generate gas file or load existing gas file
     if (fGasGeneration) {
         essential << "Starting gas generation" << endl;
@@ -831,7 +831,7 @@ string TRestDetectorGas::ConstructFilename() {
 void TRestDetectorGas::GenerateGasFile() {
     debug << "Entering ... TRestDetectorGas::GenerateGasFile( )" << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
 
     fGasFilename = ConstructFilename();
     debug << " TRestDetectorGas::GenerateGasFile. fGasFilename = " << fGasFilename << endl;
@@ -876,7 +876,7 @@ void TRestDetectorGas::SetPressure(Double_t pressure) {
     debug << "Entering ... TRestDetectorGas::SetPressure( pressure=" << pressure << " )" << endl;
 
     fPressureInAtm = pressure;
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     fGasMedium->SetPressure(fPressureInAtm * REST_Units::torr);
 #endif
 }
@@ -887,7 +887,7 @@ void TRestDetectorGas::SetTemperature(Double_t temperature) {
     debug << "Entering ... TRestDetectorGas::SetPressure( temperature=" << temperature << " )" << endl;
 
     fTemperatureInK = temperature;
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     fGasMedium->SetTemperature(temperature);
 #endif
 }
@@ -1030,7 +1030,7 @@ void TRestDetectorGas::PlotTownsendCoefficient(Double_t eMin, Double_t eMax, Int
 Double_t TRestDetectorGas::GetDriftVelocity(Double_t E) {
     debug << "Entering ... TRestDetectorGas::GetDriftVelocity( E=" << E << " )" << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     if (fStatus != RESTGAS_GASFILE_LOADED) {
         debug << "-- Error : " << __PRETTY_FUNCTION__ << endl;
         debug << "-- Error : Gas file was not loaded!" << endl;
@@ -1059,7 +1059,7 @@ Double_t TRestDetectorGas::GetDriftVelocity(Double_t E) {
 Double_t TRestDetectorGas::GetLongitudinalDiffusion(Double_t E) {
     debug << "Entering ... TRestDetectorGas::GetLongitudinalDiffusion( E=" << E << " )" << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     if (fStatus != RESTGAS_GASFILE_LOADED) {
         debug << "-- Error : " << __PRETTY_FUNCTION__ << endl;
         debug << "-- Error : Gas file was not loaded!" << endl;
@@ -1088,7 +1088,7 @@ Double_t TRestDetectorGas::GetLongitudinalDiffusion(Double_t E) {
 Double_t TRestDetectorGas::GetTransversalDiffusion(Double_t E) {
     debug << "Entering ... TRestDetectorGas::GetTransversalDiffusion( E=" << E << " )" << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     if (fStatus != RESTGAS_GASFILE_LOADED) {
         debug << "-- Error : " << __PRETTY_FUNCTION__ << endl;
         debug << "-- Error : Gas file was not loaded!" << endl;
@@ -1117,7 +1117,7 @@ Double_t TRestDetectorGas::GetTransversalDiffusion(Double_t E) {
 Double_t TRestDetectorGas::GetTownsendCoefficient(Double_t E) {
     debug << "Entering ... TRestDetectorGas::GetTownsendCoefficient( E=" << E << " )" << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     if (fStatus != RESTGAS_GASFILE_LOADED) {
         debug << "-- Error : " << __PRETTY_FUNCTION__ << endl;
         debug << "-- Error : Gas file was not loaded!" << endl;
@@ -1146,7 +1146,7 @@ Double_t TRestDetectorGas::GetTownsendCoefficient(Double_t E) {
 Double_t TRestDetectorGas::GetAttachmentCoefficient(Double_t E) {
     debug << "Entering ... TRestDetectorGas::GetAttachmentCoefficient( E=" << E << " )" << endl;
 
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     if (fStatus != RESTGAS_GASFILE_LOADED) {
         debug << "-- Error : " << __PRETTY_FUNCTION__ << endl;
         debug << "-- Error : Gas file was not loaded!" << endl;
@@ -1188,7 +1188,8 @@ void TRestDetectorGas::PrintGasInfo() {
     metadata << "Temperature : " << fTemperatureInK << " K" << endl;
     metadata << "Electric Field : " << fElectricField * units("V/cm") << " V/cm " << endl;
     metadata << "W-value : " << fW << " eV" << endl;
-    metadata << "Drift velocity : " << GetDriftVelocity(fElectricField * units("V/cm")) / units("cm/us") << " mm/us " << endl;
+    metadata << "Drift velocity : " << GetDriftVelocity(fElectricField * units("V/cm")) / units("cm/us")
+             << " mm/us " << endl;
     metadata << "Max. Electron energy : " << fMaxElectronEnergy << " eV" << endl;
     metadata << "Field grid nodes : " << fEnodes << endl;
     metadata << "Efield range : ( " << fEmin << " , " << fEmax << " ) V/cm " << endl;
diff --git a/src/TRestDetectorGeometry.cxx b/src/TRestDetectorGeometry.cxx
index 30932cfd7..0bb6ae66c 100644
--- a/src/TRestDetectorGeometry.cxx
+++ b/src/TRestDetectorGeometry.cxx
@@ -17,45 +17,39 @@
 ///_______________________________________________________________________________
 
 #include "TRestDetectorGeometry.h"
+
 using namespace std;
 
 ClassImp(TRestDetectorGeometry);
 
-//______________________________________________________________________________
-
-TRestDetectorGeometry::TRestDetectorGeometry()
-    : TGeoManager()  //, fGfGeometry(0), fDriftElec(0)
-{
-#if defined USE_Garfield
-    // TRestDetectorGeometry default constructor
-    vReadoutElec.clear();
-    vGfComponent.clear();
-    vGfSensor.clear();
-#endif
-}
-
-//______________________________________________________________________________
+TRestDetectorGeometry::TRestDetectorGeometry() : TGeoManager() {}
 
 TRestDetectorGeometry::~TRestDetectorGeometry() {
-#if defined USE_Garfield
-    // TRestDetectorGeometry destructor
+#if defined REST_GARFIELD
+    for (auto item : vReadoutElec) {
+        delete item;
+    }
     vReadoutElec.clear();
+
+    for (auto item : vGfSensor) {
+        delete item;
+    }
     vGfSensor.clear();
+
+    for (auto item : vGfComponent) {
+        delete item;
+    }
     vGfComponent.clear();
 #endif
 }
 
-//------------------------------------------------------------------------------
-
 void TRestDetectorGeometry::InitGfGeometry() {
-#if defined USE_Garfield
+#if defined REST_GARFIELD
     fGfGeometry = new Garfield::GeometryRoot();
     fGfGeometry->SetGeometry(this);
 #endif
 }
 
-//------------------------------------------------------------------------------
-
 void TRestDetectorGeometry::PrintGeometry() {
     cout << "--------------------------------------" << endl;
     cout << "Volumes : " << this->GetListOfVolumes()->GetEntries() << endl;
diff --git a/src/TRestDetectorHitsToSignalProcess.cxx b/src/TRestDetectorHitsToSignalProcess.cxx
index ec59bc781..162b091a1 100644
--- a/src/TRestDetectorHitsToSignalProcess.cxx
+++ b/src/TRestDetectorHitsToSignalProcess.cxx
@@ -170,8 +170,8 @@ void TRestDetectorHitsToSignalProcess::Initialize() {
 ///
 void TRestDetectorHitsToSignalProcess::InitProcess() {
     fGas = GetMetadata<TRestDetectorGas>();
-    if (fGas != NULL) {
-#ifndef USE_Garfield
+    if (fGas) {
+#ifndef REST_GARFIELD
         ferr << "A TRestDetectorGas definition was found but REST was not linked to Garfield libraries."
              << endl;
         ferr << "Please, remove the TRestDetectorGas definition, and add gas parameters inside the process "
@@ -279,4 +279,3 @@ TRestEvent* TRestDetectorHitsToSignalProcess::ProcessEvent(TRestEvent* evInput)
 
     return fSignalEvent;
 }
-
diff --git a/src/TRestDetectorSignalToHitsProcess.cxx b/src/TRestDetectorSignalToHitsProcess.cxx
index eae2335f3..39aba52dc 100644
--- a/src/TRestDetectorSignalToHitsProcess.cxx
+++ b/src/TRestDetectorSignalToHitsProcess.cxx
@@ -164,8 +164,8 @@ void TRestDetectorSignalToHitsProcess::Initialize() {
 ///
 void TRestDetectorSignalToHitsProcess::InitProcess() {
     fGas = GetMetadata<TRestDetectorGas>();
-    if (fGas != NULL) {
-#ifndef USE_Garfield
+    if (fGas) {
+#ifndef REST_GARFIELD
         ferr << "A TRestDetectorGas definition was found but REST was not linked to Garfield libraries."
              << endl;
         ferr << "Please, remove the TRestDetectorGas definition, and add gas parameters inside the process "
@@ -356,4 +356,3 @@ TRestEvent* TRestDetectorSignalToHitsProcess::ProcessEvent(TRestEvent* evInput)
 
     return fHitsEvent;
 }
-