Search and plot nuclear structure and decay data interactively
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NNDC Databases: 

Levels & Gammas Search

Ground and excited states (energy, T1/2, spin/parity, decay modes), Gamma rays (energy, intensity, multipolarity, coinc.)

Nuclear Wallet Cards Search

Latest Ground and isomeric states properties

Decay Radiation Search

Radiation type, energy, intensity and dose following nuclear decay

Advanced Cross-Variable Plot

Plot observable nuclide properties

Help on Decay Radiation Search


The search form allows to retrieve nuclear information from the current ENSDF decay databases files.

Retrieval parameters can be put in the search form using text boxes, drop-down menus and radio buttons. The Nucleus text box can take nuclear names, the Element text box takes element names, the remaining text boxes can only take numbers.

Please note that the corresponding radio button should be clicked on enabled for many of the conditions to take effect. Javascripts have been implemented to facilitate the use of the radio buttons; however, the user must pay attention to them.

Search Feature Examples

A few examples should clarify many of the search features.

Search on 144DY:

Search on even-A nuclei heavier than Sn (Z=50) and lighter than Yb (Z=70) that alpha-decay:

Search on Pt nuclei that produce Gamma radiation following EC/B+:

Search on fast alpha emitters with Z=80-84, T1/2 smaller than 1 ms, alpha energy larger than 7400 keV, and alpha intensity larger than 80%:

Output type

There are 2 possibilities, both of them are ASCII files with HTML elements to facilitate the viewing using a browser. In one of them, Web Page option, results are presented in a HTML table. In the other, Formatted File option, the presentation is far simpler; results are separated by a tab key.

The Formatted File option is suitable for further parsing by a computer code. A header with the name of the each column is given. Due to space limitations, many names are abbreviated:

  • Radiation: Radiation type, i.e. G for gamma, E for electron.
  • Rad subtype: Further classification of the radiation type.
  • Rad Ene.: Radiation energy in keV.
  • EP Ene.: Beta-decay end point energy in keV.
  • Rad Int.: Radiation absolute intensity.
  • Dose: Radiation dose in MeV/Bq-s
  • Unc: Uncertainties

Decay Scheme

The Web Page output option has a link to a page with a decay scheme. This scheme is rendered in a single image. If the decay scheme is too complex, only selected parts of it should be plotted at a time using the interactive features provided.

Levels will appear plotted in vertical groups based solely on energy-spacing considerations to avoid overwriting, that is, there is no physics behind how these levels are grouped in vertical structures; a change of image size or energy limits will likely modify the way these levels appear plotted.

The first time the decay scheme is plotted, all levels will be included. A form at the top of the plot can be used to replot with the following possibilities:

  • Select lower and upper energy limits.
  • Write gamma energies.
  • Write gamma intensities.
  • Write gamma multipolarities.
  • Write level energies.
  • Write level half-lives.
  • Write level spin and parities.
  • Write decay information.
  • Highlight a single level, that is, the level information will appear with a bright yellow background while other levels directly feeding or being fed by the highlighted level will appear with a lighter background
  • Choose the image height in pixels.
  • Choose the level width in pixels.
  • Choose the vertical group spacing in pixels.

Levels with unknown value of absolute energy but with a known relative energy, for instance levels noted as X+500, are plotted at an arbitrarily choosen value of 200 keV from the ground state, i.e. X+500 will appear at 700 keV.

Please, don't hesitate to email your comments.

Additional Resources

Database Manager and Web Programming:
Alejandro A. Sonzogni