Quantities Definitions
Ground State and Isomers Tab
The table lists GS and levels having half-life > 100 ns.
Nuclide
Where
Z is the number of protons,
N the number of neutrons, and
A = Z + N. A letter besides
the A number indicates the ENSDF metastable flag, and a decay dataset is
usually provided in the
Decay Radiation tab. Please note that the isomer definition has changed during
time, hence some levels listed might not have been considered as metastable at the time of the evaluation.
Energy [keV]
Gives the energy of the level, rounded to the nearest kilovolt,
0 being the ground state. Where placement of the level with respect to the ground state is unknown, this is
denoted be addition of an offset X, or Y, or Z, or W.
Sn or Sp indicate that the neutron or proton separation energy should be added.
Jπ
Angular momentum and parity of the state. Values between round brackets are uncertain (based on weak arguments,
see the ENSDF
manual pag. 103 ), values
between square brakets are assumed from theory.
T1/2 - Abundance
Half-life of the state (or STABLE ), followed by the isotopic abundance (mole-fraction).
Some states report the total width Γ in eV, keV, or MeV. The following relation holds: T
1/2(s)
≅ ℏ X ln2 / Γ = 4.562 10
-22/Γ(MeV)
T1/2[s]
Half-life converted into seconds. For the conversion, one year is 365.24219878 days, and one eV =
6.58211889e
-16 log(2).
No rounding to the original value precision is made.
Decay [%]
Decay mode and branching ratio in percent.
α: alpha particle emission (
4He nucleus)
β+: emission of an anti-electron and a neutrino. A proton inside the nucleus is transformed into a
neutron
β-: emission of an electron and an anti-neutrino. A neutron inside the nucleus is transformed into a
proton
ec: electron capture: capture of one orbital electron by the the nucleus. A proton inside the nucleus is
transformed into a neutron plus a neutrino
SF: Spontaneous Fission: a nucleus spontaneously splits into fragment nuclides
IT: Isomeric Transition: a level above the ground state decays via electromagnetic process
n: neutron emission
p: proton emission
β- n (and similar): beta- decay followed by delayed neutron emission
Note on percentage normalization:
ec β+ 100%
β+ p 23%
means that all decays are ec β+, of which 23% is β+ p
Isospin
Isobaric spin of the nuclide
Magnetic Dipole Moment μ
First multipole expansion of the nucleus magnetic moment. Measured in μ
N = eℏ /
2m
protonc
Electric Quadrupole Moment Q
Second multipole expansion of the nucleus electric moment. Measured in barns.
Charge radius R
Root-mean-square of the nuclear charge radius, expressed in fm.
Qα, Qβ, QEC, Qβ- n
Energy available for α β EC, and β- n decay, respectively. A trailing
"#" indicates
(non-experimental) estimated values.
Sn, Sp
Separation energy. The energy needed to remove one neutron or one proton, respectively, from a nuclide. A
trailing
"#" indicates (non-experimental) estimated values.
Binding/A
Binding energy per nucleon. The Binding energy is the energy required to separate all protons and neutron from
the nuclide. A trailing
"#" indicates (non-experimental) estimated values.
Atomic Mass
Mass given in Atomic Mass Units [AMU]. The AMU is defined as one twelfth of the mass of an atom
of
12C in its nuclear and electronic ground state. A trailing
"#" indicates (non-experimental)
estimated values.
Mass Excess
Difference between the Atomic Mass, expressed in AMU, and A. The Mass Excess is expressed in keV, given that
1 AMU = 931 494.061 ± 0.021 keV. A trailing
"#" indicates (non-experimental) estimated values.
Discovery
Year of discovery
Levels Tab
The table lists the Adopted Levels properties.
Nuclide
Where
Z is the number of protons,
N the number of neutrons, and
A = Z + N. A letter besides
the A number indicates the ENSDF metastable flag, and a decay dataset is
usually provided in the
Decay Radiation tab. Please note that the isomer definition has changed during
time, hence some levels listed might not have been considered as metastable at the time of the evaluation.
Ex Energy [keV]
Gives the energy of the level, rounded to the nearest keV,
0 being the ground state. Where placement of the level with respect to the ground state is unknown, this is
denoted be addition of an offset X, or Y, or Z, or W.
Sn or Sp indicate that the neutron or proton separation energy should be added.
Jπ order
Angular momentum and parity of the state. Values between round brackets are uncertain (based on weak arguments,
see the ENSDF
manual pag. 103 ), values
between square brakets are assumed from theory.
In italics is indicated the order of the occurrence of a spin value, blank means the first occurrence of
that value. 0+
3
means that there are two lower energy levels with Jπ 0+
Band
Number assigned to the band(s) to which the level is member of.
T1/2
Half-life of the state (or STABLE ), followed by the isotopic abundance (mole-fraction).
Some states report the total width Γ in eV, keV, or MeV. The following relation holds: T
1/2(s)
≅ ℏ X ln2 / Γ = 4.562 10
-22/Γ(MeV)
Decay [%]
Decay mode and branching ratio in percent.
α: alpha particle emission (
4He nucleus)
β+: emission of an anti-electron and a neutrino. A proton inside the nucleus is transformed into a
neutron
β-: emission of an electron and an anti-neutrino. A neutron inside the nucleus is transformed into a
proton
ec: electron capture: capture of one orbital electron by the the nucleus. A proton inside the nucleus is
transformed into a neutron plus a neutrino
SF: Spontaneous Fission: a nucleus spontaneously splits into fragment nuclides
IT: Isomeric Transition: a level above the ground state decays via electromagnetic process
n: neutron emission
p: proton emission
β- n (and similar): beta- decay followed by delayed neutron emission
Note on percentage normalization:
ec β+ 100%
β+ p 23%
means that all decays are ec β+, of which 23% is β+ p
Isospin
Isobaric spin
Magnetic Dipole Moment μ
First multipole expansion of the nucleus magnetic moment. Measured in μ
N = eℏ /
2m
protonc
Electric Quadrupole Moment Q
Second multipole expansion of the nucleus electric moment. Measured in barns.
Gammas Tab
The table lists the Adopted Gammas properties.
Nuclide
Where
Z is the number of protons,
N the number of neutrons, and
A = Z + N. A letter besides
the A number indicates the ENSDF metastable flag, and a decay dataset is
usually provided in the
Decay Radiation tab. Please note that the isomer definition has changed during
time, hence some levels listed might not have been considered as metastable at the time of the evaluation.
Initial Level - Final Level
Properties of the levels between which the transition takes place.
Eγ
Energy of the transition
Iγ(rel) Relative Intensity
100 is assigned to the most intense gamma from a given initial level, and other gammas relative intensities are
referred to that.
Multipolarity
Type (Magnetic or Electric), angular momentum and parity of the gamma transition.
δ Gamma ray Mixing Ratio
Usually indicated with δ. For mixed multipolarities A + B, it gives the probability of each according to :
A * 1/(1+δ
2) and B * δ
2/(1+δ
2)
αT Total Electron Conversion Coefficients
Indicated by α
it gives the probability that the transition takes place by ejecting any orbital electron according to the
formula
α = electron emission probability / gamma emission probability.
In most of the cases this is a theoretical value obtained using
BrIcc
B(EL), B(ML) Reduced Electric and Magnetic Transition Probabilities in Weisskopf
Unitss
The probability of electromagnetic transition per unit time and given multipolarity
is expressed using the Blatt and Weisskopf formula:
if mp is either M or E, and L the angular momentum
λ(mp L) = 8π / (L * [(2L+1)!! ]
2) * 1/ℏ * (E
γ /
ℏc)
2L+1 * B(mp L)
B(mp L) is the reduced transition probability, a quantity involving the wave functions of the initial and final
states.
Defining for each multipolarity the Weisskopf factor, where A is the mass number and E
γ the
energy in MeV:
W(E1) ℏ = 6.8 10-2 A2/3 Eγ3
|
W(M1) ℏ = 2.1 10-2 Eγ3
|
W(E2) ℏ = 4.9 10-8 A4/3 Eγ5
|
W(M2) ℏ= 1.5 10-8 A2/3 Eγ5
|
W(E3) ℏ = 2.3 10-14 A2 Eγ7
|
W(M3) ℏ= 6.8 10-15 A4/3 Eγ7
|
We finally define the reduced transition probability in Weisskopf units as:
Bw.u.(mp L) = B(mp L) / W(mp L)
Decay Radiation Tab
Lists the evaluated decay modes and the emitted radiations properties.
• Decay summary
Parent, Daughter
Symbol of the decaying and product nuclides, respectively
Where
Z is the number of protons,
N the number of neutrons, and
A = Z + N. A letter besides
the A number indicates the ENSDF metastable flag
T1/2
Half-life of the state.
In some cases the total width Γ in eV, keV, or MeV is reported instead. The following relation holds:
T
1/2(s) ≅ ℏ X ln2 / Γ = 4.562 10
-22/Γ(MeV)
Ex
Gives the energy of the decaying level, rounded to the nearest keV,
Jπ order
Angular momentum and parity of the state. Values between round brackets are uncertain (based on weak arguments,
see the ENSDF
manual pag. 103 ), values
between square brakets are assumed from theory.
In italics is indicated the order of the occurrence of a spin value, blank means the first occurrence of
that value. 0+
3
means that there are two lower energy levels with Jπ 0+
Decay [%]
Decay mode and branching ratio in percent.
α: alpha particle emission (
4He nucleus)
β+: emission of an anti-electron and a neutrino. A proton inside the nucleus is transformed into a
neutron
β-: emission of an electron and an anti-neutrino. A neutron inside the nucleus is transformed into a
proton
ec: electron capture: capture of one orbital electron by the the nucleus. A proton inside the nucleus is
transformed into a neutron plus a neutrino
SF: Spontaneous Fission: a nucleus spontaneously splits into fragment nuclides
IT: Isomeric Transition: a level above the ground state decays via electromagnetic process
n: neutron emission
p: proton emission
β- n (and similar): beta- decay followed by delayed neutron emission
Note on percentage normalization:
ec β+ 100%
β+ p 23%
means that all decays are ec β+, of which 23% is β+ p
Qdecay Energy available for the decay
Q values in the
Decay Radiation tab are the the ones at the time of the evaluation. They might differ
from the ones given in the
Ground State tab if the evaluation was made before 2020
• Total energy by radiation type
Energy in keV by radiation type through the decay mode, per 1 decay of the parent. Neutrino contribution is
calculated with
Betashape
Delta is difference between the calculated (Total) and the expected (Q * BR) energy
• Beta- and Beta+ radiation fields
<E>β
Mean β energy, in keV
Iβ(abs)
Absolute β intensity, in %
EEC
Energy for electron electron capture to the level
IEC(abs)
Absolute conversion electron intensity, in %
Daughter Level
Level in which the daughter nuclide is created after the parent decays
Eβ, max Maximum (end point) β energy in keV
Maximum energy of the electron, for β-, or positron, for β+, emitted in the decay
Log ft
It gives a way to conveniently compare β-decay probabilities in different nuclides, which span several
order of magnitude.
f is a function of the atomic number Z and the energy available for the decay Q
β, whilst t is
the half-life.
Transition type
Forbiddeness classification: 1U, 2U for first , second unique forbidden transition. A blank signifies an allowed
or a non-unique forbidden.
• Alpha radiation fields
Eα
α energy, in keV
Iα(abs)
Absolute α intensity, in %
Daughter Level
Level in which the daughter nuclide is created after the parent decays
HF Hindrance factor
Ratio of the measured to calculated rate, equal to the ratio of the calculated to measured half-lives.
• Gamma radiation fields
Eγ
Energy of the transition, in keV
Iγ(abs)
Absolute γ intensity, in %
Iγ(abs) β+ (only for EC + β
+ decay): absolute
γ
intensity, in %, from the β
+ decay only.
Warning, please note that this is a quantity
calculated
by removing the EC contribution, and subject to large errors.
Initial Level - Final Level
Properties of the levels between which the transition takes place.
Multipolarity
Type (Magnetic or Electric), angular momentum and parity of the gamma transition.
δ Gamma ray Mixing Ratio
Usually indicated with δ. For mixed multipolarities A + B, it gives the probability of each according to :
A * 1/(1+δ
2) and B * δ
2/(1+δ
2)
αT Total Electron Conversion Coefficients
it gives the probability that the transition takes place by ejecting any orbital electron according to the
formula
α = electron emission probability / gamma emission probability.
In most of the cases this is a theoretical value obtained using
BrIcc
• Delayed particle emission
Daughter level Level in which the daughter nuclide is created
Jπ Angular momentum ad parity of the daughter nuclide
Particle Delayed particle, N for neutron, P for proton, and A for alpha
Particle energy Delayed particle energy, in keV. The frame of reference is given in the comments.
To show the comments use the toggle on top-left of the Decay Radiation tab.
I(abs) Absolute intensity in %
Ex Energy of the intermediate state emitting the delayed particle
Width Width of the transition, in keV
ΔL Angular momentum transfer of the emitted particle
• Atomic radiation fields
E energy of the radiation in keV. For X-rays and Auger electrons, an energy range is given for
transitions grouping various atomic sub-shells. For conversion electrons
the energy is averaged over the contributing sub-shells and it is calulated using the
BrIcc code
I(abs) absolute intensity of the radiation in %
Origin atomic shell emitting the radiation
Line IUPAC
notation of
the transition.
γ , EC energy Energy of the gamma transition or electron capture respectively, causing the X-ray or
electron emission
Pshell Electron capture probability for the given β transition
αshell Conversion coefficient for the given γ transition
Fission Yields Tab
Neutron-induced Fission Yields, taken from Jeff 3.1.1
Cumulative FY
Total number of atoms produced over all time after one fission. Nuclides with T
1/2 > 1 000 y are
considered stable.
Please refer to the
JEFF documentation for more datails on the method
Independent FY
Number of atoms produced directly from one fission after prompt n emission
Thermal, Fast, 14MeV
Energy of the incident neutron