Geant4-11
hepunit.py
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1"""
2# ==================================================================
3# Python module
4#
5# This module defines physical units and constants used in HEP,
6# which are imported from CLHEP library.
7#
8# Q, 2005
9# ==================================================================
10"""
11
12# ==================================================================
13# imported from "SystemOfUnits.h"
14# ==================================================================
15millimeter = 1.
16millimeter2 = millimeter*millimeter
17millimeter3 = millimeter*millimeter*millimeter
18
19centimeter = 10.*millimeter
20centimeter2 = centimeter*centimeter
21centimeter3 = centimeter*centimeter*centimeter
22
23meter = 1000.*millimeter
24meter2 = meter*meter
25meter3 = meter*meter*meter
26
27kilometer = 1000.*meter
28kilometer2 = kilometer*kilometer
29kilometer3 = kilometer*kilometer*kilometer
30
31parsec = 3.0856775807e+16*meter
32
33micrometer = 1.e-6 *meter
34nanometer = 1.e-9 *meter
35angstrom = 1.e-10*meter
36fermi = 1.e-15*meter
37
38barn = 1.e-28*meter2
39millibarn = 1.e-3 *barn
40microbarn = 1.e-6 *barn
41nanobarn = 1.e-9 *barn
42picobarn = 1.e-12*barn
43
44# symbols
45mm = millimeter
46mm2 = millimeter2
47mm3 = millimeter3
48
49cm = centimeter
50cm2 = centimeter2
51cm3 = centimeter3
52
53m = meter
54m2 = meter2
55m3 = meter3
56
57km = kilometer
58km2 = kilometer2
59km3 = kilometer3
60
61pc = parsec
62
63#
64# Angle
65#
66radian = 1.
67milliradian = 1.e-3*radian
68degree = (3.14159265358979323846/180.0)*radian
69
70steradian = 1.
71
72# symbols
73rad = radian
74mrad = milliradian
75sr = steradian
76deg = degree
77
78#
79# Time [T]
80#
81nanosecond = 1.
82second = 1.e+9 *nanosecond
83millisecond = 1.e-3 *second
84microsecond = 1.e-6 *second
85picosecond = 1.e-12*second
86
87hertz = 1./second
88kilohertz = 1.e+3*hertz
89megahertz = 1.e+6*hertz
90
91# symbols
92ns = nanosecond
93s = second
94ms = millisecond
95
96#
97# Electric charge [Q]
98#
99eplus = 1. # positron charge
100e_SI = 1.60217733e-19 # positron charge in coulomb
101coulomb = eplus/e_SI # coulomb = 6.24150 e+18 * eplus
102
103#
104# Energy [E]
105#
106megaelectronvolt = 1.
107electronvolt = 1.e-6*megaelectronvolt
108kiloelectronvolt = 1.e-3*megaelectronvolt
109gigaelectronvolt = 1.e+3*megaelectronvolt
110teraelectronvolt = 1.e+6*megaelectronvolt
111petaelectronvolt = 1.e+9*megaelectronvolt
112
113joule = electronvolt/e_SI # joule = 6.24150 e+12 * MeV
114
115# symbols
116MeV = megaelectronvolt
117eV = electronvolt
118keV = kiloelectronvolt
119GeV = gigaelectronvolt
120TeV = teraelectronvolt
121PeV = petaelectronvolt
122
123#
124# Mass [E][T^2][L^-2]
125#
126kilogram = joule*second*second/(meter*meter)
127gram = 1.e-3*kilogram
128milligram = 1.e-3*gram
129
130# symbols
131kg = kilogram
132g = gram
133mg = milligram
134
135#
136# Power [E][T^-1]
137#
138watt = joule/second # watt = 6.24150 e+3 * MeV/ns
139
140#
141# Force [E][L^-1]
142#
143newton = joule/meter # newton = 6.24150 e+9 * MeV/mm
144
145#
146# Pressure [E][L^-3]
147#
148pascal = newton/m2 # pascal = 6.24150 e+3 * MeV/mm3
149bar = 100000*pascal # bar = 6.24150 e+8 * MeV/mm3
150atmosphere = 101325*pascal # atm = 6.32420 e+8 * MeV/mm3
151
152#
153# Electric current [Q][T^-1]
154#
155ampere = coulomb/second # ampere = 6.24150 e+9 * eplus/ns
156milliampere = 1.e-3*ampere
157microampere = 1.e-6*ampere
158nanoampere = 1.e-9*ampere
159
160#
161# Electric potential [E][Q^-1]
162#
163megavolt = megaelectronvolt/eplus
164kilovolt = 1.e-3*megavolt
165volt = 1.e-6*megavolt
166
167#
168# Electric resistance [E][T][Q^-2]
169#
170ohm = volt/ampere # ohm = 1.60217e-16*(MeV/eplus)/(eplus/ns)
171
172#
173# Electric capacitance [Q^2][E^-1]
174#
175farad = coulomb/volt # farad = 6.24150e+24 * eplus/Megavolt
176millifarad = 1.e-3*farad
177microfarad = 1.e-6*farad
178nanofarad = 1.e-9*farad
179picofarad = 1.e-12*farad
180
181#
182# Magnetic Flux [T][E][Q^-1]
183#
184weber = volt*second # weber = 1000*megavolt*ns
185
186#
187# Magnetic Field [T][E][Q^-1][L^-2]
188#
189tesla = volt*second/meter2 # tesla =0.001*megavolt*ns/mm2
190
191gauss = 1.e-4*tesla
192kilogauss = 1.e-1*tesla
193
194#
195# Inductance [T^2][E][Q^-2]
196#
197henry = weber/ampere # henry = 1.60217e-7*MeV*(ns/eplus)**2
198
199#
200# Temperature
201#
202kelvin = 1.
203
204#
205# Amount of substance
206#
207mole = 1.
208
209#
210# Activity [T^-1]
211#
212becquerel = 1./second
213curie = 3.7e+10 * becquerel
214
215#
216# Absorbed dose [L^2][T^-2]
217#
218gray = joule/kilogram
219
220#
221# Luminous intensity [I]
222#
223candela = 1.
224
225#
226# Luminous flux [I]
227#
228lumen = candela*steradian
229
230#
231# Illuminance [I][L^-2]
232#
233lux = lumen/meter2
234
235#
236# Miscellaneous
237#
238perCent = 0.01
239perThousand = 0.001
240perMillion = 0.000001
241
242
243# ==================================================================
244# imported from "PhysicalConstants.h"
245# ==================================================================
246pi = 3.14159265358979323846
247twopi = 2.*pi
248halfpi = pi/2.
249pi2 = pi*pi
250
251#
252Avogadro = 6.0221367e+23/mole
253
254# c = 299.792458 mm/ns
255# c^2 = 898.7404 (mm/ns)^2
256c_light = 2.99792458e+8 * m/s
257c_squared = c_light * c_light
258
259# h = 4.13566e-12 MeV*ns
260# hbar = 6.58212e-13 MeV*ns
261# hbarc = 197.32705e-12 MeV*mm
262h_Planck = 6.6260755e-34 * joule*s
263hbar_Planck = h_Planck/twopi
264hbarc = hbar_Planck * c_light
265hbarc_squared = hbarc * hbarc
266
267#
268electron_charge = - eplus # see SystemOfUnits.h
269e_squared = eplus * eplus
270
271# amu_c2 - atomic equivalent mass unit
272# amu - atomic mass unit
273electron_mass_c2 = 0.51099906 * MeV
274proton_mass_c2 = 938.27231 * MeV
275neutron_mass_c2 = 939.56563 * MeV
276amu_c2 = 931.49432 * MeV
277amu = amu_c2/c_squared
278
279# permeability of free space mu0 = 2.01334e-16 Mev*(ns*eplus)^2/mm
280# permittivity of free space epsil0 = 5.52636e+10 eplus^2/(MeV*mm)
281mu0 = 4*pi*1.e-7 * henry/m
282epsilon0 = 1./(c_squared*mu0)
283
284# electromagnetic coupling = 1.43996e-12 MeV*mm/(eplus^2)
285elm_coupling = e_squared/(4*pi*epsilon0)
286fine_structure_const = elm_coupling/hbarc
287classic_electr_radius = elm_coupling/electron_mass_c2
288electron_Compton_length = hbarc/electron_mass_c2
289Bohr_radius = electron_Compton_length/fine_structure_const
290
291alpha_rcl2 = fine_structure_const * classic_electr_radius \
292 * classic_electr_radius
293twopi_mc2_rcl2 = twopi * electron_mass_c2 \
294 * classic_electr_radius \
295 * classic_electr_radius
296
297#
298k_Boltzmann = 8.617385e-11 * MeV/kelvin
299
300#
301STP_Temperature = 273.15*kelvin
302STP_Pressure = 1.*atmosphere
303kGasThreshold = 10.*mg/cm3
304
305#
306universe_mean_density = 1.e-25*g/cm3
307