Geant4 11.2.2
Toolkit for the simulation of the passage of particles through matter
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SystemOfUnits.h
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1// -*- C++ -*-
2// ----------------------------------------------------------------------
3// HEP coherent system of Units
4//
5// This file has been provided to CLHEP by Geant4 (simulation toolkit for HEP).
6//
7// The basic units are :
8// millimeter (millimeter)
9// nanosecond (nanosecond)
10// Mega electron Volt (MeV)
11// positron charge (eplus)
12// degree Kelvin (kelvin)
13// the amount of substance (mole)
14// luminous intensity (candela)
15// radian (radian)
16// steradian (steradian)
17//
18// Below is a non exhaustive list of derived and pratical units
19// (i.e. mostly the SI units).
20// You can add your own units.
21//
22// The SI numerical value of the positron charge is defined here,
23// as it is needed for conversion factor : positron charge = e_SI (coulomb)
24//
25// The others physical constants are defined in the header file :
26// PhysicalConstants.h
27//
28// Authors: M.Maire, S.Giani
29//
30// History:
31//
32// 06.02.96 Created.
33// 28.03.96 Added miscellaneous constants.
34// 05.12.97 E.Tcherniaev: Redefined pascal (to avoid warnings on WinNT)
35// 20.05.98 names: meter, second, gram, radian, degree
36// (from [email protected] (STAR)). Added luminous units.
37// 05.08.98 angstrom, picobarn, microsecond, picosecond, petaelectronvolt
38// 01.03.01 parsec
39// 31.01.06 kilogray, milligray, microgray
40// 29.04.08 use PDG 2006 value of e_SI
41// 03.11.08 use PDG 2008 value of e_SI
42// 19.08.15 added liter and its sub units (mma)
43// 12.01.16 added symbols for microsecond (us) and picosecond (ps) (mma)
44// 17.07.20 use PDG 2019 value of e_SI
45// 06.05.21 added minute, hour, day, year and millielectronvolt (mma)
46
47#ifndef HEP_SYSTEM_OF_UNITS_H
48#define HEP_SYSTEM_OF_UNITS_H
49
50namespace CLHEP {
51
52 //
53 //
54 //
55 static constexpr double pi = 3.14159265358979323846;
56 static constexpr double twopi = 2*pi;
57 static constexpr double halfpi = pi/2;
58 static constexpr double pi2 = pi*pi;
59
60 //
61 // Length [L]
62 //
63 static constexpr double millimeter = 1.;
64 static constexpr double millimeter2 = millimeter*millimeter;
65 static constexpr double millimeter3 = millimeter*millimeter*millimeter;
66
67 static constexpr double centimeter = 10.*millimeter;
68 static constexpr double centimeter2 = centimeter*centimeter;
69 static constexpr double centimeter3 = centimeter*centimeter*centimeter;
70
71 static constexpr double meter = 1000.*millimeter;
72 static constexpr double meter2 = meter*meter;
73 static constexpr double meter3 = meter*meter*meter;
74
75 static constexpr double kilometer = 1000.*meter;
76 static constexpr double kilometer2 = kilometer*kilometer;
77 static constexpr double kilometer3 = kilometer*kilometer*kilometer;
78
79 static constexpr double parsec = 3.0856775807e+16*meter;
80
81 static constexpr double micrometer = 1.e-6 *meter;
82 static constexpr double nanometer = 1.e-9 *meter;
83 static constexpr double angstrom = 1.e-10*meter;
84 static constexpr double fermi = 1.e-15*meter;
85
86 static constexpr double barn = 1.e-28*meter2;
87 static constexpr double millibarn = 1.e-3 *barn;
88 static constexpr double microbarn = 1.e-6 *barn;
89 static constexpr double nanobarn = 1.e-9 *barn;
90 static constexpr double picobarn = 1.e-12*barn;
91
92 // symbols
93 static constexpr double nm = nanometer;
94 static constexpr double um = micrometer;
95
96 static constexpr double mm = millimeter;
97 static constexpr double mm2 = millimeter2;
98 static constexpr double mm3 = millimeter3;
99
100 static constexpr double cm = centimeter;
101 static constexpr double cm2 = centimeter2;
102 static constexpr double cm3 = centimeter3;
103
104 static constexpr double liter = 1.e+3*cm3;
105 static constexpr double L = liter;
106 static constexpr double dL = 1.e-1*liter;
107 static constexpr double cL = 1.e-2*liter;
108 static constexpr double mL = 1.e-3*liter;
109
110 static constexpr double m = meter;
111 static constexpr double m2 = meter2;
112 static constexpr double m3 = meter3;
113
114 static constexpr double km = kilometer;
115 static constexpr double km2 = kilometer2;
116 static constexpr double km3 = kilometer3;
117
118 static constexpr double pc = parsec;
119
120 //
121 // Angle
122 //
123 static constexpr double radian = 1.;
124 static constexpr double milliradian = 1.e-3*radian;
125 static constexpr double degree = (pi/180.0)*radian;
126
127 static constexpr double steradian = 1.;
128
129 // symbols
130 static constexpr double rad = radian;
131 static constexpr double mrad = milliradian;
132 static constexpr double sr = steradian;
133 static constexpr double deg = degree;
134
135 //
136 // Time [T]
137 //
138 static constexpr double nanosecond = 1.;
139 static constexpr double second = 1.e+9 *nanosecond;
140 static constexpr double millisecond = 1.e-3 *second;
141 static constexpr double microsecond = 1.e-6 *second;
142 static constexpr double picosecond = 1.e-12*second;
143
144 static constexpr double minute = 60*second;
145 static constexpr double hour = 60*minute;
146 static constexpr double day = 24*hour;
147 static constexpr double year = 365*day;
148
149 static constexpr double hertz = 1./second;
150 static constexpr double kilohertz = 1.e+3*hertz;
151 static constexpr double megahertz = 1.e+6*hertz;
152
153 // symbols
154 static constexpr double ns = nanosecond;
155 static constexpr double s = second;
156 static constexpr double ms = millisecond;
157 static constexpr double us = microsecond;
158 static constexpr double ps = picosecond;
159
160 //
161 // Electric charge [Q]
162 //
163 static constexpr double eplus = 1. ;// positron charge
164 static constexpr double e_SI = 1.602176634e-19;// positron charge in coulomb
165 static constexpr double coulomb = eplus/e_SI;// coulomb = 6.24150 e+18 * eplus
166
167 //
168 // Energy [E]
169 //
170 static constexpr double megaelectronvolt = 1. ;
171 static constexpr double electronvolt = 1.e-6*megaelectronvolt;
172 static constexpr double kiloelectronvolt = 1.e-3*megaelectronvolt;
173 static constexpr double gigaelectronvolt = 1.e+3*megaelectronvolt;
174 static constexpr double teraelectronvolt = 1.e+6*megaelectronvolt;
175 static constexpr double petaelectronvolt = 1.e+9*megaelectronvolt;
176 static constexpr double millielectronvolt = 1.e-9*megaelectronvolt;
177
178 static constexpr double joule = electronvolt/e_SI;// joule = 6.24150 e+12 * MeV
179
180 // symbols
181 static constexpr double MeV = megaelectronvolt;
182 static constexpr double eV = electronvolt;
183 static constexpr double keV = kiloelectronvolt;
184 static constexpr double GeV = gigaelectronvolt;
185 static constexpr double TeV = teraelectronvolt;
186 static constexpr double PeV = petaelectronvolt;
187
188 //
189 // Mass [E][T^2][L^-2]
190 //
191 static constexpr double kilogram = joule*second*second/(meter*meter);
192 static constexpr double gram = 1.e-3*kilogram;
193 static constexpr double milligram = 1.e-3*gram;
194
195 // symbols
196 static constexpr double kg = kilogram;
197 static constexpr double g = gram;
198 static constexpr double mg = milligram;
199
200 //
201 // Power [E][T^-1]
202 //
203 static constexpr double watt = joule/second;// watt = 6.24150 e+3 * MeV/ns
204
205 //
206 // Force [E][L^-1]
207 //
208 static constexpr double newton = joule/meter;// newton = 6.24150 e+9 * MeV/mm
209
210 //
211 // Pressure [E][L^-3]
212 //
213#define pascal hep_pascal // a trick to avoid warnings
214 static constexpr double hep_pascal = newton/m2; // pascal = 6.24150 e+3 * MeV/mm3
215 static constexpr double bar = 100000*pascal; // bar = 6.24150 e+8 * MeV/mm3
216 static constexpr double atmosphere = 101325*pascal; // atm = 6.32420 e+8 * MeV/mm3
217
218 //
219 // Electric current [Q][T^-1]
220 //
221 static constexpr double ampere = coulomb/second; // ampere = 6.24150 e+9 * eplus/ns
222 static constexpr double milliampere = 1.e-3*ampere;
223 static constexpr double microampere = 1.e-6*ampere;
224 static constexpr double nanoampere = 1.e-9*ampere;
225
226 //
227 // Electric potential [E][Q^-1]
228 //
229 static constexpr double megavolt = megaelectronvolt/eplus;
230 static constexpr double kilovolt = 1.e-3*megavolt;
231 static constexpr double volt = 1.e-6*megavolt;
232
233 //
234 // Electric resistance [E][T][Q^-2]
235 //
236 static constexpr double ohm = volt/ampere;// ohm = 1.60217e-16*(MeV/eplus)/(eplus/ns)
237
238 //
239 // Electric capacitance [Q^2][E^-1]
240 //
241 static constexpr double farad = coulomb/volt;// farad = 6.24150e+24 * eplus/Megavolt
242 static constexpr double millifarad = 1.e-3*farad;
243 static constexpr double microfarad = 1.e-6*farad;
244 static constexpr double nanofarad = 1.e-9*farad;
245 static constexpr double picofarad = 1.e-12*farad;
246
247 //
248 // Magnetic Flux [T][E][Q^-1]
249 //
250 static constexpr double weber = volt*second;// weber = 1000*megavolt*ns
251
252 //
253 // Magnetic Field [T][E][Q^-1][L^-2]
254 //
255 static constexpr double tesla = volt*second/meter2;// tesla =0.001*megavolt*ns/mm2
256
257 static constexpr double gauss = 1.e-4*tesla;
258 static constexpr double kilogauss = 1.e-1*tesla;
259
260 //
261 // Inductance [T^2][E][Q^-2]
262 //
263 static constexpr double henry = weber/ampere;// henry = 1.60217e-7*MeV*(ns/eplus)**2
264
265 //
266 // Temperature
267 //
268 static constexpr double kelvin = 1.;
269
270 //
271 // Amount of substance
272 //
273 static constexpr double mole = 1.;
274
275 //
276 // Activity [T^-1]
277 //
278 static constexpr double becquerel = 1./second ;
279 static constexpr double curie = 3.7e+10 * becquerel;
280 static constexpr double kilobecquerel = 1.e+3*becquerel;
281 static constexpr double megabecquerel = 1.e+6*becquerel;
282 static constexpr double gigabecquerel = 1.e+9*becquerel;
283 static constexpr double millicurie = 1.e-3*curie;
284 static constexpr double microcurie = 1.e-6*curie;
285 static constexpr double Bq = becquerel;
286 static constexpr double kBq = kilobecquerel;
287 static constexpr double MBq = megabecquerel;
288 static constexpr double GBq = gigabecquerel;
289 static constexpr double Ci = curie;
290 static constexpr double mCi = millicurie;
291 static constexpr double uCi = microcurie;
292
293 //
294 // Absorbed dose [L^2][T^-2]
295 //
296 static constexpr double gray = joule/kilogram ;
297 static constexpr double kilogray = 1.e+3*gray;
298 static constexpr double milligray = 1.e-3*gray;
299 static constexpr double microgray = 1.e-6*gray;
300
301 //
302 // Luminous intensity [I]
303 //
304 static constexpr double candela = 1.;
305
306 //
307 // Luminous flux [I]
308 //
309 static constexpr double lumen = candela*steradian;
310
311 //
312 // Illuminance [I][L^-2]
313 //
314 static constexpr double lux = lumen/meter2;
315
316 //
317 // Miscellaneous
318 //
319 static constexpr double perCent = 0.01 ;
320 static constexpr double perThousand = 0.001;
321 static constexpr double perMillion = 0.000001;
322
323} // namespace CLHEP
324
325#endif /* HEP_SYSTEM_OF_UNITS_H */
pascal
#define pascal
Definition SystemOfUnits.h:213