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 */