Magill J., Galy J. Radioactivity Radionuclides Radiation

Подождите немного. Документ загружается.

184 Glossary

Nucleons

Protons and neutrons.

Nucleosynthesis

The processes in stars by which increasingly heavy nuclei are made from protons and neutrons

to create the elements in nature.

Nucleus

The central core of an atom that contains most of its mass. Experiments performed in 1909

by Geiger and Marsden (under the direction of Rutherford) led to the discovery of a nuclear

structure. The nucleus is positively charged and contains one or more nucleons (protons or

neutrons). The positive charge of the nucleus is determined by the number of protons it

contains; in the neutral atom this positive charge is balanced by an equal number of negatively

charged electrons orbiting the nucleus in a comparatively large region outside it.

Pair Production

The creation of an electron and a positron from a photon in a strong electric ﬁeld, such as

that surrounding an atomic nucleus. The electron and the positron each have a mass of about

9 × 10

−31

kg, which is equivalent on the basis of the mass-energy equation to a total of

16 × 10

−14

J. The frequency associated with a photon of this energy is 2.5 × 10

Hz. Pair

production thus requires photons of high quantum energy (Bremsstrahlung or gamma rays).

Any excess energy is taken up as kinetic energy of the products.

Photon

A particle with zero rest mass consisting of a quantum of electromagnetic radiation. The

photon may also be regarded as a unit of energy equal to hf, where h is the Planck constant

and f is the frequency of the radiation in hertz. Photons travel at the speed of light. They are

required to explain the photoelectric effect and other phenomena that require light to have

particle character.

Planck’s Constant

The fundamental constant in nature that relates the energy and wavelength of quantum particles.

Positron

The antiparticle of the electron.

Primordial Radionuclides

Naturally occurring radionuclides with very long half-lives.

Proton

An elementary particle that is stable, bears a positive charge equal in magnitude to that of the

electron and has a mass of 1.672614 × 10

−27

kg, which is 1836.12 times that of the electron.

The proton occurs in all atomic nuclei.

Quality Factor

The factor by which the absorbed dose (gray or rad) is to be multiplied to obtain a quantity

that expresses, on a common scale for all ionizing radiation, the biological damage (sievert

or rem) to an exposed individual. It is used because some types of radiation, such as alpha

particles, are more biologically damaging internally than other types.

Quark

There are six kinds of quark and they interact via the strong, weak, and electromagnetic forces.

Particles such as protons and neutrons are made up of these elementary quarks.

Glossary 185

r-Process (Rapid Process)

The explosive process believed to occur in type II supernovae in which nuclei rapidly capture

neutrons on a timescale fast in comparison with the beta decay process. As a result several

neutrons can be captured before beta decay occurs.

Rad

The old unit of absorbed dose of ionising radiation (1 rad = 0.01 Gy, see Gray).

Radiation Weighting Factor, w

The radiation weighting factor is a dimensionless factor to derive the equivalent dose from the

absorbed dose averaged over a tissue or organ and is based on the quality of the radiation.

Radioactive Equilibrium

The equilibrium reached by a radioactive series in which the rate of decay of each nuclide is

equal to its rate of production. It follows that all rates of decay of the different nuclides within

the sample are equal when radioactive equilibrium is achieved. For example, in the uranium

series, uranium-238 decays to thorium-234. Initially, the rate of production of thorium will

exceed the rate at which it is decaying and the thorium content of the sample will rise. As the

amount of thorium increases, its activity increases; eventually a situation is reached in which

the rate of production of thorium is equal to its rate of decay. The proportion of thorium in

the sample will then remain constant. Thorium decays to produce protactinium-234; some

time after the stabilisation of the thorium content, the protactinium content will also stabilise.

When the whole radioactive series attains stabilisation, the sample is said to be in radioactive

equilibrium.

Radioactive Series

A series of radioactive nuclides in which each member of the series is formed by the decay

of the nuclide before it. The series ends with a stable nuclide. Three radioactive series occur

naturally, those headed by thorium-232 (thorium series), uranium-235 (actinium series), and

uranium-238 (uranium series). All three series end with an isotope of lead. The neptunium

series starts with the artiﬁcial isotope plutonium-241, which decays to neptunium-237, and

ends with bismuth-209.

Radioactivity

The spontaneous disintegration of certain atomic nuclei accompanied by the emission of

alpha-particles (helium nuclei), beta-particles (electrons or positrons), or gamma radiation

(short-wavelength electromagnetic waves).

Radioisotope

An isotope of an element that is radioactive.

Radionuclide

A nuclide that is radioactive.

RDD

Radiological Dispersion Devices, also known as “Dirty Bombs”, make use of conventional

explosive to disperse radioactive material in the atmosphere.

RDE

Radiological Dispersion Event.

Reference Man

A person with the anatomical and physiological characteristics of an average individual which

is used in calculations assessing internal dose (also may be called “Standard Man”).

186 Glossary

Rem

The old unit of equivalent dose (1 rem  0.01 sievert, see Sievert).

Rest Energy

The rest mass of a body expressed in energy terms according to the relationship E = m

where m

is the rest mass of the body and c is the speed of light.

Rest Mass

The mass of a body at rest when measured by an observer who is at rest in the same frame of

reference.

Risk factor

The relationship between the radiation dose and the likelihood of incurring a stochastic effect

can be expressed as a risk factor i.e.

likelihood of incurring a stochastic effect = Dose (Sv) · Risk Factor (Sv

−1

)

ICRP risk factors for stochastic effects (ICRP 60)

Exposed Fatal Non-fatal Heredirory Total

population cancers cancers effect

Adult workers 0.04 0.01 0.01 0.06

Whole population 0.05 0.01 0.01 0.07

Roentgen (R)

The roentgen is the amount of exposure that will create 2.58 × 10

−4

C of singly charged ions

in 1 kg of air at STP. Since about 34 eV of energy is needed to produce one ion pair, 1 R

corresponds to an energy absorption per unit mass of 0.0088 J kg

−1

s-Process (Slow Process)

The process of nucleosysthesis in red giants whereby nuclei capture neutrons on a timescale

that is slower compared with beta decay.

Shell Model of the Nucleus

A model of the atomic nucleus in which nucleons are assumed to move under the inﬂuence

of a central ﬁeld in shells that are analogous to atomic electron shells. The model provides a

good explanation of the stability of nuclei that have magic numbers.

SI Units

Système International d’Unités: the internationl system of units recommended for scientiﬁc

purposes.

Sievert (Sv)

The new international system (SI) unit for dose equivalent equal to 1 Joule/kilogram. 1 sievert

= 100 rem. The equivalent dose in sieverts is equal to the absorbed dose in grays multiplied

by the quality factor.

SNAP

Systems for Nuclear Auxiliary Power.

Glossary 187

Spent Fuel

Nuclear fuel which has been used for energy production in a nuclear reactor and whose

nuclide composition has been (partially) modiﬁed by ﬁssion and neutron capture processes

and subsequent radioactivity decay.

Spontaneous Emission

The emission of a photon by an atom as it makes a transition from an excited state to the

ground state. Spontaneous emission occurs independently of any external electromagnetic

radiation; the transition is caused by interactions between atoms and vacuum ﬂuctuations

of the quantised electromagnetic ﬁeld. The process of spontaneous emission, which cannot

be described by nonrelativistic quantum mechanics, as given by formulations such as the

Schrödinger equation, is responsible for the limited lifetime of an excited state of an atom

before it emits a photon.

Standard Model of Particle Physics see Lepton

Stochastic Effects

For stochastic effects, the probability of occurrence (but not the severity) depends on the

radiation dose. The main type of stochastic effects following exposure are the incidence of

cancer and of hereditary disease in their descendents.

STP

Standard temperature (T = 273.15 K) and pressure (p = 0.1MPa).

Strong Interaction

The strong interaction, some 100 times stronger than the electromagnetic interaction, func-

tions only between hadrons and is responsible for the force between nucleons that gives the

atomic nucleus its great stability. It operates at very short range inside the nucleus (as little as

−15

metre) and is visualised as an exchange of virtual mesons.

Supernovae Type II

Refers to massive stars (10 to 30 times the mass of our sun) which end their life in a gigantic

explosion.

Thomson Scattering

The scattering of electromagnetic radiation by free charged particles, especially electrons,

when the photon energy is small compared with the energy equivalent of the rest mass of the

charged particles. The energy lost by the radiation is accounted for by classical theory as a

result of the radiation transmitted by the charged particles when they are accelerated in the

transverse electric ﬁeld of the radiation. It is named after Sir J. J. Thomson.

Tissue Weighting Factor, w

The factor by which the equivalent dose in a tissue or organ is weighted to represent the relative

contribution of that tissue or organ to the total detriment resulting from uniform irradiation of

the body.

Transmutation

The transformation of an atomic nucleus into another nucleus by radioactive decay or by

nuclear reactions.

188 Glossary

Uncertainty Principle

An intrinsic characteristic of quantum mechanics whereby the precision with which linked

variables such as position and momentum, or energy and time, can be determined simultane-

ously is limited.

UNSCEAR

United Nations Scientiﬁc Committee on the Effects of Atomic Radiation.

Reference

Many deﬁnitions can be found on the website:

http://physics.about.com/cs/glossary/a/glossary.htm

Appendices

Appendix A

Physical Constants, Conversion Factors, Preﬁxes, Greek Alphabet

Table A.1. Physical constants

∗

Quantity Symbol Value

Electron rest mass m

9.109 381 88(72) × 10

−31

5.485 799 110(12) × 10

−4

0.510 998 902(21) MeV c

−2

Electron charge e 1.602 176 462(63) × 10

−19

Proton rest mass m

1.672 621 58(13) × 10

−27

1.007 276 466 88(13) u

938.271 998(38) MeV c

−2

Neutron rest mass m

1.674 927 16(13) × 10

−27

1.008 664 915 78(55) u

939.565330(38) MeV c

−2

Alpha particle mass m

4.001 506 1747(10) u

Atomic mass unit u 1.660 538 73(13) × 10

−27

(1 u = M(

C)/12) 931.494 013(37) MeV c

−2

Speed of light c 2.997 924 58 × 10

−1

Avogadro’s number N

6.022 141 99(47) × 10

mol

−1

Boltzmann constant k 1.380 6503(24) × 10

−23

−1

Planck’s constant h 6.626 0688 × 10

−34

4.135 6673 × 10

−15

eV s

Reference

∗

P. J. Mohr and B. N. Taylor: The 1998 CODATA Recommended Values of the Fundamental

Physical Constants, Web Version 3.1, available at physics.nist.gov/cuu/index.html (National

Institute of Standards and Technology, Gaithersburg, MD 20899, 3 December 1999)

190 Appendices

Table A.2. Conversion factors

1 year (365.25 days) 3.15576 × 10

1 month

∗∗

2.6298 × 10

1 week 6.048 × 10

1 day 8.640 × 10

1 curie 3.7 × 10

∗∗

1 month = 1 year/12 = 2.6298 × 10

Table A.3. Radiation dose, dose rate, and conversion factors

Dose Symbol Unit Abbreviation SI unit

SI unit

Absorbed D gray Gy 1 Gy = 1 J kg

−1

dose

(formerly rad) (rd) (1 rd = 0.01 Gy)

Equivalent H sievert Sv 1 Sv

∼

1Jkg

−1

dose

(formerly rem) (rem) (1 rem

∼

0.01 Sv)

Absorbed dD/dt Gy/s (Gy/h) 1 Gy/s = 1 J kg

−1

dose rate

(rd/s) (1 rd/s = 0.01 Gy/s)

Equivalent dH/dt Sv/s (Sv/h) 1 Sv/s = 1 J kg

−1

dose rate

(rem/s) (1 rem/s = 0.01 Gy/s)

Table A.4. List of preﬁxes

Preﬁx Unit Factor

yotta Y 10

kilo k 10

nano n 10

−9

zetta Z 10

hecto h 10

pico p 10

−12

exa E 10

deka da 10

femto f 10

−15

peta P 10

deci d 10

−1

atto a 10

−18

tera T 10

centi c 10

−2

zepto z 10

−21

giga G 10

milli m 10

−3

yocto y 10

−24

mega M 10

micro µ 10

−6

Table A.5. The Greek alphabet

A, α alpha I, ι iota P, ρ rho

B, β beta

K, κ kappa Σ, σ sigma

, γ gamma

, λ lambda T, τ tau

, δ delta

M, µ mu Y, υ upsilon

E, ε epsilon

N, ν nu , φ phi

Z, ζ zeta

, ξ xi X, χ chi

H, η eta

O, o omicron Ψ, ψ psi

, θ theta

, π pi , ω omega

Appendix B: Table of the Elements 191

Appendix B

Table of the Elements

Reference

Elementymology Elements Multidict, Peter van der Krogt, see website at

http://www.vanderkrogt.net/elements/

English German French Spanish Russian

Symbol Z Name Name Nom Nombre Nazvanie

Ac 89 Actinium Actinium Actinium Actinio Aktini

Ag 47 Silver Silber Argent Plata Serebro

Al 13 Aluminium Aluminium Aluminium Aluminio Almini

Am 95 Americium Americium Américium Americio Americi

Ar 18 Argon Argon Argon Argón Argon

As 33 Arsenic Arsen Arsenic Arsénico Myxk

At 85 Astatine Astat Astate Astatino Astatin

Au 79 Gold Gold Or Oro Zoloto

B 5 Boron Bor Bore Boro Bor

Ba 56 Barium Barium Baryum Bario Bari

Be 4 Beryllium Beryllium Béryllium Berilio Berilli

Bh 107 Bohrium Bohrium Bohrium Bohrio Bori

Bi 83 Bismuth Bismut Bismuth Bismuto Vismut

Bk 97 Berkelium Berkelium Berkélium Berkelio Berkeli

Br 35 Bromine Brom Brome Bromo Brom

C 6 Carbon Kohlenstoff Carbone Carbono Uglerod

Ca 20 Calcium Calcium Calcium Calcio Kalci

Cd 48 Cadmium Cadmium Cadmium Cadmio Kadmi

Ce 58 Cerium Cer Cérium Cerio Ceri

Cf 98 Californium Californium Californium Californio Kaliforni

Cl 17 Chlorine Chlor Chlore Cloro Hlor

Cm 96 Curium Curium Curium Curio Kri

Co 27 Cobalt Cobalt Cobalt Cobalto Kobalt

Cr 24 Chromium Chrom Chrome Cromo Hrom

Cs 55 Caesium Caesium Caesium Cesio Cezi

Cu 29 Copper Kupfer Cuivre Cobre Med

Db 105 Dubnium Dubnium Dubnium Dubnio Dubni

Ds 110 Darmstadtium Darmstadtium Darmstadtium Darmstadtium Darmctadi

Dy 66 Dysprosium Dysprosium Dysprosium Disprosio Disprozi

Er 68 Erbium Erbium Erbium Erbio rbi

Es 99 Einsteinium Einsteinium Einsteinium Einsteinio nxteni

Eu 63 Europium Europium Europium Europio Evropi

F 9 Fluorine Fluor Fluor Flúor Ftor

Fe 26 Iron Eisen Fer Hierro elezo

Fm 100 Fermium Fermium Fermium Fermio Fermi

Fr 87 Francium Francium Francium Francio Franci

192 Appendices

English German French Spanish Russian

Symbol Z Name Name Nom Nombre Nazvanie

Ga 31 Gallium Gallium Gallium Galio Galli

Gd 64 Gadolinium Gadolinium Gadolinium Gadolinio Gadolini

Ge 32 Germanium Germanium Germanium Germanio Germani

H 1 Hydrogen Wasserstoff Hydrogène Hydrógeno Vodorod

He 2 Helium Helium Helium Helio Geli

Hf 72 Hafnium Hafnium Hafnium Hafnio Gafni

Hg 80 Mercury Quecksilber Mercure Mercurio Rtut

Ho 67 Holmium Holmium Holmium Holmio Golmi

Hs 108 Hassium Hassium Hassium Hassio Hassi

I 53 Iodine Iod Iode Yodo od

In 49 Indium Indium Indium Indio Indi

Ir 77 Iridium Iridium Iridium Iridio Iridi

K 19 Potassium Kalium Potassium Potasio Kali

Kr 36 Krypton Krypton Krypton Criptón Kripton

La 57 Lanthanum Lanthan Lanthane Lantano Lantan

Li 3 Lithium Lithium Lithium Litio Liti

Lr 103 Lawrencium Lawrencium Lawrencium Lawrencio Lourensi

Lu 71 Lutetium Lutetium Lutétium Lutecio Lteci

Md 101 Mendelevium Mendelevium Mendélévium Mendelevio Mendelevi

Mg 12 Magnesium Magnesium Magnésium Magnesio Magni

Mn 25 Manganese Mangan Manganèse Manganeso Marganec

Mo 42 Molybdenum Molybdän Molybdène Molibdeno Molibden

Mt 109 Meitnerium Meitnerium Meitnerium Meitnerio Matneri

N 7 Nitrogen Stickstoff Azote Nitrógeno Azot

Na 11 Sodium Natrium Sodium Sodio Natri

Nb 41 Niobium Niob Niobium Niobio Niobi

Nd 60 Neodymium Neodym Néodyme Neodimio Neodim

Ne 10 Neon Neon Néon Neón Neon

Ni 28 Nickel Nickel Nickel Níquel Nikel

No 102 Nobelium Nobelium Nobélium Nobelio Nobeli

Np 93 Neptunium Neptunium Neptunium Neptunio Neptuni

O 8 Oxygen Sauerstoff Oxygène Oxígeno Kislorod

Os 76 Osmium Osmium Osmium Osmio Osmi

P 15 Phosphorus Phosphor Phosphore Fósforo Fosfor

Pa 91 Protactinium Protactinium Protactinium Protactinio Protaktini

Pb 82 Lead Blei Plomb Plomo Svinec

Pd 46 Palladium Palladium Palladium Paladio Palladi

Pm 61 Promethium Promethium Prométhium Prometio Prometi

Po 84 Polonium Polonium Polonium Polonio Poloni

Pr 59 Praseodymium Praseodym Praséodyme Praseodimio Prazeodim

Pt 78 Platinium Platin Platine Platino Platina

Pu 94 Plutonium Plutonium Plutonium Plutonio Plutoni

Appendix B: Table of the Elements 193

English German French Spanish Russian

Symbol Z Name Name Nom Nombre Nazvanie

Ra 88 Radium Radium Radium Radio Radi

Rb 37 Rubidium Rubidium Rubidium Rubidio Rubidi

Re 75 Rhenium Rhenium Rhénium Renio Reni

Rf 104 Rutherfordium Rutherfordium Rutherfordium Rutherfordio Ruterfordi

Rh 45 Rhodium Rhodium Rhodium Rodio Rodi

Rn 86 Radon Radon Radon Radón Radon

Ru 44 Ruthenium Ruthenium Ruthénium Rutenio Ruteni

S 16 Sulfur Schwefel Soufre Azufre Sera

Sb 51 Antimony Antimon Antimoine Antimonio Surma

Sc 21 Scandium Scandium Scandium Escandio Skandi

Se 34 Selenium Selen Sélénium Selenio Selen

Sg 106 Seaborgium Seaborgium Seaborgium Seaborgio Siborgi

Si 14 Silicon Silicium Silicium Silicio Kremni

Sm 62 Samarium Samarium Samarium Samario Samari

Sn 50 Tin Zinn Etain Esta˜no Olovo

Sr 38 Strontium Strontium Strontium Estroncio Stronci

Ta 73 Tantalum Tantal Tantale Tántalo Tantal

Tb 65 Terbium Terbium Terbium Terbio Terbi

Tc 43 Technetium Technetium Technétium Tecnecio Tehneci

Te 52 Tellurium Tellur Tellure Telurio Tellur

Th 90 Thorium Thorium Thorium Torio Tori

Ti 22 Titanium Titan Titane Titanio Titan

Tl 81 Thallium Thallium Thallium Talio Talli

Tm 69 Thulium Thulium Thulium Tulio Tuli

U 92 Uranium Uran Uranium Uranio Ura n

Uuu 111 Unununium Unununium Unununium Unununium

Uub 112 Ununbium Ununbium Ununbium Ununbium

Uut 113 Ununtrium Ununtrium Ununtrium Ununtrium

Uuq 114 Ununquadium Ununquadium Ununquadium Ununquadium

Uuh 116 Ununhexium Ununhexium Ununhexium Ununhexium

Uuo 118 Ununoctium Ununoctium Ununoctium Ununoctium

V 23 Vanadium Vanadium Vanadium Vanadio Vanadi

W 74 Tungsten Wolfram Tungstène Volframio Volfram

Xe 54 Xenon Xenon Xénon Xenón Ksenon

Y 39 Yttrium Yttrium Yttrium Itrio Ittri

Yb 70 Ytterbium Ytterbium Ytterbium Iterbio Itterbi

Zn 30 Zinc Zink Zinc Cinc Cink

Zr 40 Zirconium Zirconium Zirconium Circonio Cirkoni