WWW Table of Nuclear Structure Glossary

a b c d e f g h i j k l m n o p q r s t u v w x y z

A - Mass number. Sum of the protons and neutrons in the atomic nucleus.

Atomic Mass - Atomic mass M and its one standard deviation error.

Binding Energy/A - Tabulated binding energy per nucleon defined as

    B/A = [Z*M(¹H) + N*M(¹n) - M(A,Z)]/A

and its one standard deviation error.

Element - Symbol for nucleus with atomic number Z.

Energy - Energy of level or gamma ray in keV.

ENSDF - Evaluated Nuclear Structure Data File maintained by the National Nuclear Data Center, Brookhaven National Laboratory.

Final level energy - Energy of level populated by a gamma ray transition.

Half-life or t1/2 - Half-life of level in selected units.

Initial level energy - Energy of level deexcited by a gamma ray transition.

Internal conversion coefficient - Ratio of conversion electrons to gamma rays emitted by a transition.

JPI - Combination of spin and parity assigned to a level. Multiple JPI values for a level list possible assignments.

keV = 1000 eV = 1:073 544 171(92)x10^-6 u = 1.602 176 53(14)x10^-19 Joules

Level order index - Order number of level in nucleus. Levels are numbered starting from 1 for the ground state and incrementing for each excited state.

Mass Excess - Mass excess [M(in u) - A], in keV, and its one standard deviation error.

Mixing ratio - Ratio of contributions of multipolarities in a mixed multipolarity gamma ray transition.

μ (micro) = 10^-6

Multipolarity - Electric (E) or magnetic (M) classification of a gamma ray transition that carries of L units of angular momentum. Values vary from M1-M5 and E0-E5 where E0 transitions can only occur by internal conversion or pair production processes. Transitions of mixed multipolarity, e.g. M1+E2 are common.

N - Neutron number. Number of neutrons in the atomic nucleus.

Parity - A nucleus or particle has odd (-) or even (+) parity according to whether or not its wave function changes sign when all of the space coordinates are changed.

Q - S indicating a systematic assignment or ? indicating a questionable assignment.

Q(2β-) - Double β- decay energy defined as Q(2β-) = M(A,Z) - M(A,Z+2).

Q(4β-) - Four β- decay energy defined as Q(4β-) = M(A,Z) - M(A,Z+4).

Q(α) - α decay energy defined as Q(α) = M(A,Z) - M(A-4,Z-2) - ⁴He.

Q(β-) - β- decay energy defined as Q(β-) = M(A,Z) - M(A,Z+1).

Q(β-n) - β- delayed neutron emission decay energy defined as Q(β-) = M(A,Z) - M(A-1,Z+1) - n.

Q(d,α) - (d,α) reaction energy defined as Q(d,α) = M(A,Z) - M(A-2,Z-1) - ²H - ⁴He.

Q(EC) - Electron capture decay energy defined as Q(EC) = M(A,Z) - M(A,Z-1).

Q(ECp) - Electron capture delayed proton emission decay energy defined as Q(ECp) = M(A,Z) - M(A-1,Z-2) - ¹H.

Q(n,α) - (n,α) reaction energy defined as Q(n,α) = M(A,Z) - M(A-3,Z-2) - ⁴He + n.

Q(p,α) - (p,α) reaction energy defined as Q(p,α) = M(A,Z) - M(A-3,Z-1) - ⁴He + p.

Relative intensity - Intensity of gamma ray relative to other gamma rays emitted by a level. Normally the most intense gamma ray is normalized to 100.

Rotational Band - Group of levels that exhibit a common structure consistent with quantized rotation of the nucleus.

S(2n) - Two neutron separation energy defined as S(2n) = -M(A,Z) + M(A-2,Z) + 2n

S(2p) - Neutron separation energy defined as S(2p) = -M(A,Z) + M(A-2,Z-2) + 2¹H

S(n) - Neutron separation energy defined as S(n) = -M(A,Z) + M(A-1,Z) + n

Sorting - The resulting table can be sorted by the selected fields. Default sorting is by A, Z, and energy.

S(p) - Proton separation energy defined as S(p) = -M(A,Z) + M(A-1,Z-1) + ¹H

Spin - Angular momentum of the nucleus.

Superdeformed Band - A rotational band in a highly deformed nucleus where the ratio of major to minor axis is ~1.5-2/1.

Total intensity - Relative gamma ray intensity multiplied by 1+ICC (conversion coefficient).

u (atomic mass unit) = 931.494 043(80) MeV = 1.660 538 86(28)x10^-27 kg

Weisskopf (BWi) strength - Weisskopf single-particle transition probability for a gamma ray transitions calculated by the ratio of experimental and theoretical lifetimes. Values are given for each multipolarity component. BW1 refers to first multipolarity and BW2 refers to second multipolarity.

Yrast order index - Levels numbered by whether they are the first (Yrast), second (Yrare), or higher occurrence of a level with each given spin.

Z - Atomic number. Number of protons in the atomic nucleus.

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