SystemOfUnits.h

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// -*- C++ -*-
// ----------------------------------------------------------------------
// HEP coherent system of Units
//
// This file has been provided to CLHEP by Geant4 (simulation toolkit for HEP).
//
// The basic units are :
//          millimeter              (millimeter)
//      nanosecond              (nanosecond)
//      Mega electron Volt      (MeV)
//      positron charge         (eplus)
//      degree Kelvin           (kelvin)
//              the amount of substance (mole)
//              luminous intensity      (candela)
//      radian                  (radian)
//              steradian               (steradian)
//
// Below is a non exhaustive list of derived and pratical units
// (i.e. mostly the SI units).
// You can add your own units.
//
// The SI numerical value of the positron charge is defined here,
// as it is needed for conversion factor : positron charge = e_SI (coulomb)
//
// The others physical constants are defined in the header file :
//          PhysicalConstants.h
//
// Authors: M.Maire, S.Giani
//
// History:
//
// 06.02.96   Created.
// 28.03.96   Added miscellaneous constants.
// 05.12.97   E.Tcherniaev: Redefined pascal (to avoid warnings on WinNT)
// 20.05.98   names: meter, second, gram, radian, degree
//            (from Brian.Lasiuk@yale.edu (STAR)). Added luminous units.
// 05.08.98   angstrom, picobarn, microsecond, picosecond, petaelectronvolt
// 01.03.01   parsec
// 28.04.06   import from CLHEP to GaudiKernel -- HD
// 11.05.06   Rename pascal to Pa to avoid warnings on Windows - MC

#ifndef GAUDI_SYSTEM_OF_UNITS_H
#define GAUDI_SYSTEM_OF_UNITS_H


namespace Gaudi {
  namespace Units {

    //
    // Length [L]
    //
    constexpr double millimeter  = 1.;
    constexpr double millimeter2 = millimeter*millimeter;
    constexpr double millimeter3 = millimeter*millimeter*millimeter;

    constexpr double centimeter  = 10.*millimeter;
    constexpr double centimeter2 = centimeter*centimeter;
    constexpr double centimeter3 = centimeter*centimeter*centimeter;

    constexpr double meter  = 1000.*millimeter;
    constexpr double meter2 = meter*meter;
    constexpr double meter3 = meter*meter*meter;

    constexpr double kilometer = 1000.*meter;
    constexpr double kilometer2 = kilometer*kilometer;
    constexpr double kilometer3 = kilometer*kilometer*kilometer;

    constexpr double parsec = 3.0856775807e+16*meter;

    constexpr double micrometer = 1.e-6 *meter;
    constexpr double  nanometer = 1.e-9 *meter;
    constexpr double  angstrom  = 1.e-10*meter;
    constexpr double  fermi     = 1.e-15*meter;

    constexpr double      barn = 1.e-28*meter2;
    constexpr double millibarn = 1.e-3 *barn;
    constexpr double microbarn = 1.e-6 *barn;
    constexpr double  nanobarn = 1.e-9 *barn;
    constexpr double  picobarn = 1.e-12*barn;

    // symbols
    constexpr double nm  = nanometer;
    constexpr double um  = micrometer;

    constexpr double mm  = millimeter;
    constexpr double mm2 = millimeter2;
    constexpr double mm3 = millimeter3;

    constexpr double cm  = centimeter;
    constexpr double cm2 = centimeter2;
    constexpr double cm3 = centimeter3;

    constexpr double m  = meter;
    constexpr double m2 = meter2;
    constexpr double m3 = meter3;

    constexpr double km  = kilometer;
    constexpr double km2 = kilometer2;
    constexpr double km3 = kilometer3;

    constexpr double pc = parsec;

    //
    // Angle
    //
    constexpr double radian      = 1.;
    constexpr double milliradian = 1.e-3*radian;
    constexpr double degree = (3.14159265358979323846/180.0)*radian;

    constexpr double   steradian = 1.;

    // symbols
    constexpr double rad  = radian;
    constexpr double mrad = milliradian;
    constexpr double sr   = steradian;
    constexpr double deg  = degree;

    //
    // Time [T]
    //
    constexpr double nanosecond  = 1.;
    constexpr double second      = 1.e+9 *nanosecond;
    constexpr double millisecond = 1.e-3 *second;
    constexpr double microsecond = 1.e-6 *second;
    constexpr double  picosecond = 1.e-12*second;
    constexpr double femtosecond = 1.e-15*second;

    constexpr double hertz = 1./second;
    constexpr double kilohertz = 1.e+3*hertz;
    constexpr double megahertz = 1.e+6*hertz;

    // symbols
    constexpr double ns = nanosecond;
    constexpr double  s = second;
    constexpr double ms = millisecond;

    //
    // Electric charge [Q]
    //
    constexpr double eplus = 1. ;       // positron charge
    constexpr double e_SI  = 1.60217733e-19;    // positron charge in coulomb
    constexpr double coulomb = eplus/e_SI;  // coulomb = 6.24150 e+18 * eplus

    //
    // Energy [E]
    //
    constexpr double megaelectronvolt = 1.;
    constexpr double     electronvolt = 1.e-6*megaelectronvolt;
    constexpr double kiloelectronvolt = 1.e-3*megaelectronvolt;
    constexpr double gigaelectronvolt = 1.e+3*megaelectronvolt;
    constexpr double teraelectronvolt = 1.e+6*megaelectronvolt;
    constexpr double petaelectronvolt = 1.e+9*megaelectronvolt;

    constexpr double joule = electronvolt/e_SI; // joule = 6.24150 e+12 * MeV

    // symbols
    constexpr double MeV = megaelectronvolt;
    constexpr double  eV = electronvolt;
    constexpr double keV = kiloelectronvolt;
    constexpr double GeV = gigaelectronvolt;
    constexpr double TeV = teraelectronvolt;
    constexpr double PeV = petaelectronvolt;

    //
    // Mass [E][T^2][L^-2]
    //
    constexpr double  kilogram = joule*second*second/(meter*meter);
    constexpr double      gram = 1.e-3*kilogram;
    constexpr double milligram = 1.e-3*gram;

    // symbols
    constexpr double  kg = kilogram;
    constexpr double   g = gram;
    constexpr double  mg = milligram;

    //
    // Power [E][T^-1]
    //
    constexpr double watt = joule/second;   // watt = 6.24150 e+3 * MeV/ns

//
// Force [E][L^-1]
//
    constexpr double newton = joule/meter;  // newton = 6.24150 e+9 * MeV/mm

    //
    // Pressure [E][L^-3]
    //
    constexpr double Pa         = newton/m2; // pascal = 6.24150 e+3 * MeV/mm3
    constexpr double bar        = 100000*Pa; // bar    = 6.24150 e+8 * MeV/mm3
    constexpr double atmosphere = 101325*Pa; // atm    = 6.32420 e+8 * MeV/mm3

    //
    // Electric current [Q][T^-1]
    //
    constexpr double      ampere = coulomb/second; // ampere = 6.24150 e+9 * eplus/ns
    constexpr double milliampere = 1.e-3*ampere;
    constexpr double microampere = 1.e-6*ampere;
    constexpr double  nanoampere = 1.e-9*ampere;

    //
    // Electric potential [E][Q^-1]
    //
    constexpr double megavolt = megaelectronvolt/eplus;
    constexpr double kilovolt = 1.e-3*megavolt;
    constexpr double     volt = 1.e-6*megavolt;

    //
    // Electric resistance [E][T][Q^-2]
    //
    constexpr double ohm = volt/ampere; // ohm = 1.60217e-16*(MeV/eplus)/(eplus/ns)

    //
    // Electric capacitance [Q^2][E^-1]
    //
    constexpr double farad = coulomb/volt;  // farad = 6.24150e+24 * eplus/Megavolt
    constexpr double millifarad = 1.e-3*farad;
    constexpr double microfarad = 1.e-6*farad;
    constexpr double  nanofarad = 1.e-9*farad;
    constexpr double  picofarad = 1.e-12*farad;

    //
    // Magnetic Flux [T][E][Q^-1]
    //
    constexpr double weber = volt*second;   // weber = 1000*megavolt*ns

    //
    // Magnetic Field [T][E][Q^-1][L^-2]
    //
    constexpr double tesla     = volt*second/meter2;    // tesla =0.001*megavolt*ns/mm2

    constexpr double gauss     = 1.e-4*tesla;
    constexpr double kilogauss = 1.e-1*tesla;

    //
    // Inductance [T^2][E][Q^-2]
    //
    constexpr double henry = weber/ampere;  // henry = 1.60217e-7*MeV*(ns/eplus)**2

    //
    // Temperature
    //
    constexpr double kelvin = 1.;

    //
    // Amount of substance
    //
    constexpr double mole = 1.;

    //
    // Activity [T^-1]
    //
    constexpr double becquerel = 1./second;
    constexpr double curie = 3.7e+10 * becquerel;

    //
    // Absorbed dose [L^2][T^-2]
    //
    constexpr double gray = joule/kilogram;

    //
    // Luminous intensity [I]
    //
    constexpr double candela = 1.;

    //
    // Luminous flux [I]
    //
    constexpr double lumen = candela*steradian;

    //
    // Illuminance [I][L^-2]
    //
    constexpr double lux = lumen/meter2;

    //
    // Miscellaneous
    //
    constexpr double perCent     = 0.01;
    constexpr double perThousand = 0.001;
    constexpr double perMillion  = 0.000001;

  }  // namespace Units
} // namespace Gaudi


#endif /* GAUDI_SYSTEM_OF_UNITS_H */