Gabriele Cosmo
138 lines
3.9 KiB
C++
138 lines
3.9 KiB
C++
// -*- C++ -*-
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// ----------------------------------------------------------------------
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// HEP coherent Physical Constants
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//
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// This file has been provided by Geant4 (simulation toolkit for HEP).
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//
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// The basic units are :
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// millimeter
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// nanosecond
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// Mega electron Volt
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// positon charge
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// degree Kelvin
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// amount of substance (mole)
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// luminous intensity (candela)
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// radian
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// steradian
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//
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// Below is a non exhaustive list of Physical CONSTANTS,
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// computed in the Internal HEP System Of Units.
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//
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// Most of them are extracted from the Particle Data Book :
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// Phys. Rev. D volume 50 3-1 (1994) page 1233
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//
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// ...with a meaningful (?) name ...
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//
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// You can add your own constants.
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//
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// Author: M.Maire
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//
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// History:
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//
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// 23.02.96 Created
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// 26.03.96 Added constants for standard conditions of temperature
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// and pressure; also added Gas threshold.
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// 29.04.08 Use PDG 2006 values
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// 03.11.08 Use PDG 2008 values
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// 17.07.20 Use PDG 2019 values
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// 06.05.21 Added Bohr_magneton and nuclear_magneton constants
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#ifndef HEP_PHYSICAL_CONSTANTS_H
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#define HEP_PHYSICAL_CONSTANTS_H
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#include "CLHEP/Units/SystemOfUnits.h"
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namespace CLHEP {
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//
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//
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//
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static constexpr double Avogadro = 6.02214076e+23/mole;
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//
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// c = 299.792458 mm/ns
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// c^2 = 898.7404 (mm/ns)^2
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//
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static constexpr double c_light = 2.99792458e+8 * m/s;
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static constexpr double c_squared = c_light * c_light;
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//
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// h = 4.13566e-12 MeV*ns
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// hbar = 6.58212e-13 MeV*ns
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// hbarc = 197.32705e-12 MeV*mm
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//
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static constexpr double h_Planck = 6.62607015e-34 * joule*s;
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static constexpr double hbar_Planck = h_Planck/twopi;
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static constexpr double hbarc = hbar_Planck * c_light;
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static constexpr double hbarc_squared = hbarc * hbarc;
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//
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//
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//
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static constexpr double electron_charge = - eplus; // see SystemOfUnits.h
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static constexpr double e_squared = eplus * eplus;
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//
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// amu_c2 - atomic equivalent mass unit
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// - AKA, unified atomic mass unit (u)
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// amu - atomic mass unit
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//
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static constexpr double electron_mass_c2 = 0.510998910 * MeV;
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static constexpr double proton_mass_c2 = 938.272013 * MeV;
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static constexpr double neutron_mass_c2 = 939.56536 * MeV;
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static constexpr double amu_c2 = 931.494028 * MeV;
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static constexpr double amu = amu_c2/c_squared;
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//
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// permeability of free space mu0 = 2.01334e-16 Mev*(ns*eplus)^2/mm
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// permittivity of free space epsil0 = 5.52636e+10 eplus^2/(MeV*mm)
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//
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static constexpr double mu0 = 4*pi*1.e-7 * henry/m;
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static constexpr double epsilon0 = 1./(c_squared*mu0);
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//
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// electromagnetic coupling = 1.43996e-12 MeV*mm/(eplus^2)
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//
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static constexpr double elm_coupling = e_squared/(4*pi*epsilon0);
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static constexpr double fine_structure_const = elm_coupling/hbarc;
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static constexpr double classic_electr_radius = elm_coupling/electron_mass_c2;
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static constexpr double electron_Compton_length = hbarc/electron_mass_c2;
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static constexpr double Bohr_radius = electron_Compton_length/fine_structure_const;
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static constexpr double alpha_rcl2 = fine_structure_const
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*classic_electr_radius
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*classic_electr_radius;
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static constexpr double twopi_mc2_rcl2 = twopi*electron_mass_c2
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*classic_electr_radius
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*classic_electr_radius;
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static constexpr double Bohr_magneton = (eplus*hbarc*c_light)/(2*electron_mass_c2);
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static constexpr double nuclear_magneton = (eplus*hbarc*c_light)/(2*proton_mass_c2);
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//
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//
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//
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static constexpr double k_Boltzmann = 8.617333e-11 * MeV/kelvin;
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//
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//
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//
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static constexpr double STP_Temperature = 273.15*kelvin;
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static constexpr double STP_Pressure = 1.*atmosphere;
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static constexpr double kGasThreshold = 10.*mg/cm3;
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//
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//
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//
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static constexpr double universe_mean_density = 1.e-25*g/cm3;
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} // namespace CLHEP
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#endif /* HEP_PHYSICAL_CONSTANTS_H */
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