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units.py

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# $Id: units.py,v 1.2 2007/08/03 11:08:10 hmd Exp $
"""
 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)
"""

# 
# Length [L]
#
millimeter  = 1.                        
millimeter2 = millimeter*millimeter
millimeter3 = millimeter*millimeter*millimeter

centimeter  = 10.*millimeter   
centimeter2 = centimeter*centimeter
centimeter3 = centimeter*centimeter*centimeter

meter  = 1000.*millimeter                  
meter2 = meter*meter
meter3 = meter*meter*meter

kilometer = 1000.*meter                   
kilometer2 = kilometer*kilometer
kilometer3 = kilometer*kilometer*kilometer

parsec = 3.0856775807e+16*meter

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

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

# symbols
mm  = millimeter                        
mm2 = millimeter2
mm3 = millimeter3

cm  = centimeter   
cm2 = centimeter2
cm3 = centimeter3

m  = meter                  
m2 = meter2
m3 = meter3

km  = kilometer                   
km2 = kilometer2
km3 = kilometer3

pc = parsec

#
# Angle
#
radian      = 1.                  
milliradian = 1.e-3*radian
degree = (3.14159265358979323846/180.0)*radian
steradian = 1.

# symbols
rad  = radian   
mrad = milliradian
sr   = steradian
deg  = degree

#
# Time [T]
#
nanosecond  = 1.
second      = 1.e+9 *nanosecond
millisecond = 1.e-3 *second
microsecond = 1.e-6 *second
picosecond  = 1.e-12*second

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

# symbols
ns = nanosecond                 
s  = second
ms = millisecond

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

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

joule = electronvolt/e_SI       # joule = 6.24150 e+12 * MeV

# symbols
MeV = megaelectronvolt
eV  = electronvolt
keV = kiloelectronvolt
GeV = gigaelectronvolt
TeV = teraelectronvolt
PeV = petaelectronvolt

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

# symbols
kg = kilogram
g  = gram
mg = milligram

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

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

#
# Pressure [E][L^-3]
#
#define pascal hep_pascal                          # a trick to avoid warnings 
pascal     = newton/m2     # pascal = 6.24150 e+3 * MeV/mm3
bar        = 100000*pascal # bar    = 6.24150 e+8 * MeV/mm3
atmosphere = 101325*pascal # atm    = 6.32420 e+8 * MeV/mm3

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

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

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

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

#
# Magnetic Flux [T][E][Q^-1]
#
weber = volt*second     # weber = 1000*megavolt*ns

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

gauss     = 1.e-4*tesla
kilogauss = 1.e-1*tesla

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

#
# Temperature
#
kelvin = 1.

#
# Amount of substance
#
mole = 1.

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

#
# Absorbed dose [L^2][T^-2]
#
gray = joule/kilogram 

#
# Luminous intensity [I]
#
candela = 1.

#
# Luminous flux [I]
#
lumen = candela*steradian

#
# Illuminance [I][L^-2]
#
lux = lumen/meter2

#
# Miscellaneous
#
perCent     = 0.01 
perThousand = 0.001
perMillion  = 0.000001

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