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Navigation guide

To zoom, move, or reset use the control panel on the top-left.
You can alternatively: Click the Hide icon to show only the Detail Tab Panel.
Click Lock icon to display the summary nuclide info in a fixed panel besides the chart. Click again the button to restore the running mode. Click the Filter icon to open a simple filter panel.

The centered nuclide is displayed in red, its possible ancestors in black, its possible offspring in white, and all other nuclides are in the background. To reset the chart, press the * key or click the reset button


Simple filter


Clicking the button opens a filter panel. Make your selection and press "Search". The filtered nuclides will be highlighted on the Livechart.

See below the "Search and Filter" section for the advanced filter option


Color zones


(This choice does not affect Half-life and Main decay mode color codes).
Value splits the max-min range in slots of equal size. Some slots might be without population.
Quantile splits the max-min range in slots of equals population. The slots have different size.
As example select 233U cumulative fission yield and switch between the two options.


Quantities Definitions


Ground State and Isomers Tab

The table lists GS and levels having half-life > 100 ns.

Nuclide
A
Z
Ce  
N
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: T1/2(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 μN = eℏ / 2mprotonc

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
A
Z
Ce  
N
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: T1/2(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 μN = eℏ / 2mprotonc

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
A
Z
Ce  
N
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+δ2) and B * δ2/(1+δ2)

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 * (Eγ / 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 Eγ 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
A
Z
Ce  
N
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: T1/2(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 Qgs → gs form AME2016 + the energy of the decaying level. Since some ENSDF datasets were evaluated before AME2016, the reported Qgs → gs might differ from the ones in the original ENSDF source (links to the original ENSDF are present in the "Nuclide" and "Decay Radiation" tabs). The differences in the Q values may affect alpha-decay hindrance factors, logft values, and excitation energies in neutron- and proton-resonance datasets including IAS/IAR type of datasets. The original ENSDF Q-values are reported on top of β- and α- radiations datatables.

• 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 Qβ, 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+δ2) and B * δ2/(1+δ2)

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 T1/2 > 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

Data sources


The main source are the Evaluated Nuclear Structure Data Files (ENSDF) snapshot April 2022, except for:
Q-values, S-values, Atomic masses: 2020 Atomic Mass Evaluation (AME2020)
Abundances: Nubase 2020 (Nubase2020)
Charge Radii: I.Angeli, K.P. Marinova, Atomic Data and Nuclear Data Tables 99 (2013) 69-95 DOI:10.1016/j.adt.2011.12.006
Neutron Cross Sections: S.F. Mughabghab, Atlas of Neutron Resonances Elsevier Science, April 17, 2006. (Exfor # V1001, V1002) and indc-nds-440
Nuclear Moments: Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments ndc-nds-0594
Year of Discovery: M. Thoennessen, The Discovery of Isotopes, Springer International 2016, ISBN 978-3-319-31761 DOI:10.1007/978-3-319-31761-3-2
Beta and neutrino spectra obtained using Betashape X. Mougeot, Physical Review C 91, 055504 and Erratum Phys. Rev. C 92, 059902 (2015)
Bremsstrahlung spectra obtained with Radlist
Atomic shell transition yields : see E.Schönfeld, H.Janßen and its references.
Atomic shell energies from Evaluated Atomic Data Library
Fission Yields: Joint Evaluated Fission and Fusion File (JEFF) 3.1.1

Note on Q values
Q values in the Decay Radiation tab are the Qgs → gs form AME2016 + the energy of the decaying level.
Since some ENSDF datasets were evaluated before AME2016, the reported Qgs → gs might differ from the ones in the original ENSDF source (links to the original ENSDF are present in the "Nuclide" and "Decay Radiation" tabs).
The differences in the Q values may affect alpha-decay hindrance factors, logft values, and excitation energies in neutron- and proton-resonance datasets including IAS/IAR type of datasets.
The original ENSDF Q-values are reported on top of β- and α- radiations datatables.

Search & Filter

The Search and Filter link on the top bar opens a query panel.


As example, select β - n as decay mode an press Search. The Livechart now displays only nuclides decaying β - n

The query panel allows refined searches like, for example,
show all gammas having energy between 450 and 500 keV, that are the key line, and emitted with an half-life between 10 and 100 days
It has plotting functionalities, see its guide for further explanation.

email: nds.contact-point