Try NIST or Karlsruher Nuklidkarte.

A further tip. Try to find your nuclides in the french DDEP data bank www. nuclide.org/ddep....

As far as I know, Nudat is strongly connected to the Nuclear Data Sheets, i.e. ENSDF(Evaluated Nuclear Structure Data File). These are _evaluated_ data, i.e. recommended values. Naturally, not every publicated half life can and will be (immediatly) incoporated into ENSDF.

You can find all references in the ENSDF database, also on the nndc webpage.

Thanks for both your replies. I managed to find the ENSDF link in the end, but it' was a little hidden away. So here's the link if anyone else needs it: http://www.nndc.bnl.gov/ensdf/#

The Janis interface ( http://www.oecd-nea.org/janis/ ) from NEA/OECD provides a convenient means of searching nuclear data from several sources, including the JEFF evaluated data.

And there :

http://laraweb.free.fr/

http://ie.lbl.gov/toi/index.asp

http://www.nucleide.org/DDEP_WG/DDEPdata.htm

is the site maintained at Laboratoire National Henri Becquerel-France

Basic metrology question, so try BIPM-Website.

http://www.bipm.org/en/publications/monographie-ri-5.html

"The purpose of this monograph, number 5 in the series, is to present the recommended values of nuclear and decay data for a wide range of radionuclides."

Hi!

The ENSDF data is compiled in the Nudat2 database. The nice thing about it is that the web interface is basically a chart of the nuclides. For more detailed information you can follow the links. The address is> http://www.nndc.bnl.gov/nudat2/

Cheers,

Vladimir

The values on the LNHB website (nucleide.org) are produced by the DDEP collaboration, which come highly recommended (I may be biassed). The advantage DDEP has over for example ENSDF for half life data is that the focus is on producing high quality decay data and the evaluators are generally measurement scientists intimately familiar with the techniques used to measure the half lives.

The DDEP website (see Maria's link above) is probably the best place to access this data as it is the most up-to-date and the "comments" sections - which explain how the data was arrived at - are also located here. DDEP isn't fully comprehensive though and this is where the ENSDF and JEFF (see JANIS) databases really come into their own. ENSDF and JEFF are both excellent databases serving slightly different purposes although I'd still regard DDEP as the "gold standard".

Other databases: NUDAT is derived from ENSDF which is related to Nuclear Data Sheets. LARA is a search engine derived from DDEP and NUDAT. JANIS is a "front end" for a number of databases including JEFF. BIPM Monographie 5 is a regular "snapshot" of the latest DDEP data.

On the geochronology front, uranium half lives are a source of contention. Some think the best published values have unrealistically low uncertainties. It ought to be possible to reproduce these measurements by rebuilding the kit used, however I don't think anyone has ever seriously tried.

Andy

You may visit nndc website.

The NUDAT is a good source of information, but you should understand how this information is compiled. The basic source of data is the ENSDF database and NUDAT is updated periodically from this database. The policy for maintaining the ENSDF database poses some restrictions and the database is updated when a complete and consistent re-evaluation of relevant physical quantities is done. This means that more precise partial information from new experiments may be available, but it is entered into the database only after the evaluation process is complete. Hence some delay.

Another source of information is the "live Chart of Nuclides" from the IAEA available at "https://www-nds.iaea.org/". Note that the principal original source of information is again the ENSDF database, but the interface is somewhat different and the updating ferquency may differ. There is no such thing as "the best up-to-date" source of information, other than the two mentioned above. You may consider accessing the ENSDF database directly, but for specific applications there may exist other dedicated databases that contain relevant information. Please, check the above mentioned sites for additional information

Good luck, Andrej

Very convenient access to the ENSDF database is available via the KAERI website:

http://atom.kaeri.re.kr/

Regards, VB

Although this thread has been inactive for a while, some might be interested to see a recent paper in Geochimica et Cosmochimica:

IUPAC-IUGS status report on the half-lives of 238U, 235U and 234U

https://www.researchgate.net/publication/284013913_IUPAC-IUGS_status_report_on_the_half-lives_of_238U_235U_and_234U

Regards-------Marwan

Article IUPAC-IUGS status report on the half-lives of 238U, 235U and 234U

Have a look on following link

http://www.nature.com/articles/srep36617

All data that is relevant for metrological use in radioactivity is available at the BIPM. Access is free.

http://www.bipm.org/en/publications/scientific-output/monographie-ri-5.html

The collection is based on the international DDEP-Projekt:

http://www.nucleide.org/DDEP_WG/DDEPdata.htm

Systeme International (SI) units [81 SI], ISO 31 recommendations [92 ISO] and Guide for the Expression of Uncertainty in Measurement [93 GUM] are used.