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Nuclear Training Services Ltd.
On-Line Practical Gamma-Ray Spectrometry Course

Copyright © 2000 Dr Gordon Gilmore

Constants
Index
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Time Scaling Factors
UnitAbbrev.Seconds
Year
(ans -Fr)		a31557600
Dayd86400
Hourh3600
Minutem60
Seconds1
Millisecondms0.001
Microsecondms10-6
Nanosecondns10-9
Picosecondps10-12
Nuclear Masses
Mass of electronME0.000548484u
Mass of protonMP1.007276548u
Mass of neutronMN1.008664923u
Mass of Hydrogen AtomMH1.007825032u
Energy equivalent of electron mass 511.0keV
Energy equivalent of atomic mass unit 931.66MeV
Basic Nuclear Data
Constant>SymbolValueMeaning
Avogadro's NumberNA6.022045×1023Number of atoms in one gram-atom or mole of material.
Planck's Constanth6.626176×10-34Js
Speed of lightc299792458 ms-1 - speed of light in a vacuum
JouleJ8.987548×1016kg - mass equivalent
Atomic Mass Unitu1.6605655×10-27
931.66
1.492684×10-10		 kg - 1/12 the mass of a 12C atom.
MeV - nuclear energy equivalent
J - energy equivalent
Electron VolteV1.602177E-19

1.0733533×10-09		J - energy expressed in terms of energy gained by electron in moving through 1 volt potential difference
u - mass equivalent
Miscellaneous Equations and Definitions
ItemMeaning
Einstein Equation E(J) = m(kg) × c2Example: 60Co
Mass Number (A)Number of nucleons in nucleus60
MAMass of Atom59.9338222 u
MparticlesMass of nucleons + Mass of electrons60.49217898 u
MnucleusMass of nucleus59.91572224 u
Mass ExcessMass of Atom - Mass number-0.066178 u
Mass DefectMass of Atom - Z × MH - N × MN
(actual mass of atom - sum of mass of nucleons and electrons)		-0.558356781 u
Binding Energy-(mass defect) = Z × MP + N × MN - Mass of nucleus0.558356781 u

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