Problem with the decay chain of Pu-244 and the JEFF database

July 25th, 2017
by Joseph Magill

Qu.(from M.R. KTE Karlsruhe): We encountered a problem while reproducing the decay chain of Pu-244.
The first decay is an α-decay to U-240 followed by a β-decay to Np-240. The question is if U-240 decays to the metastable or directly to the ground state of Np-240. In the universal nuclide chart application in Nucleonica it shows a difference between the JEFF (Np-240) and ENDF (Np-240m) databases.
When using the Decay Engine++ application only the Np240 ground state is shown. The (more like a juristical) problem is that our regulations only include the metastable state.
Do you have additional information about the decay of U-240? Which one is the physical correct daughter?

Ans.(Nucleonica Team): Indeed there is an error in the JEFF3.1 database. You can also see this clearly in the KNCO application where you see that U-240 decays to Np-240m only. In view of this, we have changed the data in JEFF3.1 for U-240 – allowing only the decay to Np-240m. This you can see in the Nuclide Datasheets.
If you now redo the decay calculation for Pu-244, you will see the Np240m is much more important than Np240.
Thanks again for pointing this out and hopefully it did not cause to much inconvenience. It just shows once again how important it is to have a number of databases for comparison purposes.

Posted in FAQs, Nucleonica | Comments

New Blog category for Forum and FAQ posts

July 18th, 2017
by Joseph Magill

From 2017, Forum and FAQ posts will be hosted together in a new Blog category FAQs.
Pre-2017 Forum and FAQ posts have been moved to Wiki page FAQs.

Posted in FAQs, Nucleonica | Comments

JRC users now with access to the KNCO++

July 17th, 2017
by Joseph Magill

All users from the European Commission’s Joint Research Centre (JRC) now have additional access to the Karlsruhe Nuclide Chart Online (KNCO++). This has been arranged through a new license agreement from June 2017 between the JRC and Nucleonica GmbH.
KNCO_JRCThe Karlsruhe Nuclide Chart Online, KNCO++, provides the latest new and updated experimental data for ground states and isomers with structured and accurate information on the half-lives, decay modes and energies of the emitted radiations. For information on training courses on the Nucleonica portal and the Karlsruhe Nuclide Chart please contact the Nucleonica Team at info@nucleonica.com.

More information
Karlsruhe Nuclide Chart Online (KNCO++) wiki page

Posted in Karlsruhe Nuclide Chart, Nucleonica | Comments

I have registered with Nucleonica, but did not receive am email with login details

June 29th, 2017
by Joseph Magill

Qu. I have registered with Nucleonica using the SIGN UP NOW form, but did not receive am email with login details
Ans. If you do not receive the confirmation e-mail with your username and password directly following registration, please check your Spam folder (see image below).
Ty

Posted in FAQs, Nucleonica | Comments

Difference between the D&S H+(10) and D&S++ for dose calculations?

June 26th, 2017
by Joseph Magill

Qu. I have difficulties to understand the differences between D&S++ and D&S H*(10). I read the wiki, but still find myself wondering what causes the difference in calculation.
Ans. The main differences between D&S++ and D&S H*(10) are the following:
1. Short-lived daughters are included automatically in H*(10) version but not the ++ version.
2. Buildup calculations are now more accurate in H*(10) than in the ++.
Most importantly:
3. Internationally standardised H*(10) is calculated rather than the Htis in the ++ version. The difference between H*(10) and Htis is that Htis just calculates the dose absorbed in a thin layer near the surface. In the H*(10) the dose is calculated at a distance of 10 mm inside the surface and also takes account of backscattering from behind the point in question. i.e. H*(10) makes two additional calculations (1) the attenuation over a distance 10mm is calculated and (2) backscattering from deeper tissue to the surface. See image below.H10doserate

Qu.:It’s still confusing for me. What I am not understanding: what is the difference in the calculation, between what was done before, and what is done now. Is it just a coefficient which change in the formula? Which one? Or the whole principle which change? The definition of H*(10) and Htis is understood, but not the way it is computed, I think this is the main problem.
Ans.:It is not just a change in a coefficient. Its really a different principle.
To calculate H*(10), one first calculates the kerma rate at the surface Kair.  The kerma is similar to the exposure or the dose rate in air at the surface (approximately!).
Knowing the kerma rate at the surface one then calculates H*(10) inside the body using H*(10) = Kair * (H*(10)/Kair). The quantity in brackets in a function of energy and has to be calculated for every gamma energy by Monte Carlo. 
This function evaluated using Monte Carlo and is shown here..
This section gives a detailed description of how H*(10) is calculated in Nucleonica. Its all a bit mathematical but at the end of the day, it gives values which are about 10-20% higher than those calculated using D&S++ (i.e. Htis).

Qu. You state that H*(10) should give results 10-20% higher – can you expand?
Ans.: Consider Co-60: H*(10) = 0.3539 µSv/h using D&S H*(10) no shielding. Htis = 0.337 µSv/h using D&S++ no shielding. So for Co-60 the H*(10) values is about 5% higher than the Htis value. The reason why the H*(10) is higher than Htis is due to scattering of radiation from deeper inside the bode back to the surface. This is neglected in the calculation for Htis.

We have introduced this H*(10) on the request of some users. For official declarations, only the H*(10) is acceptable and not the Htis as calculated in D&S++.

More info…
Nucleonica Support

Posted in FAQs, Nucleonica | Comments

New Nucleonica Landing Page

June 22nd, 2017
by Joseph Magill

The Nucleonica landing page at www.nucleonica.com has undergone a complete redesign to make it more compatible with tablet and mobile devices using the principles of Responsive Web Design.
NuLP1Nucleonica Landing Page at www.nucleonica.com. The main graphic shows how the page is displayed on a PC. The inset shows the page on a mobile device.

– The landing page provides links to the most important information for potential users: Applications, Pricing, Clients, KNCShop (Karlsruhe Nuclide Chart Shop). For users interested in registering for Free Restricted access, the SIGN UP NOW buttons are shown prominently. Existing users can access the portal via the login button with username and password.
– The new Landing Page features are supported by most major browsers including Chrome, Firefox, Internet Explorer, Safari.

More Information:
Responsive Web Design (Wikipedia)
The Landing Page description in the Nucleonica Wiki

Posted in Karlsruhe Nuclide Chart, Nucleonica | Comments

Karlsruhe Nuclide Chart Online – Literature references now available

May 31st, 2017
by Joseph Magill

Following user requests, the Karlsruhe Nuclide Chart Online (KNCO) has now been updated to provide the literature references for the nuclide chart updates in the various editions. This allows users to trace the literature references used in the nuclide data evaluation process.Pt196In the example above the references for Pt 196 are shown. From the KNCO, the nuclide Pt 196 is selected. Using the right mouse click, a Show References link leads to the latest references for this nuclide also shown above. The references are subdivided according to the edition (e.g. 10th, 9th, 8th). For each edition the entries are arranged according to Spin and Parity, Half-life, Radiations/Decay Modes, and Cross-sections.

More information
Karlsruhe Nuclide Chart Online (KNCO) wiki page

Posted in Karlsruhe Nuclide Chart, Nucleonica | Comments

Beta Dose Rate Application with Personal Dose Equivalent Hp(0.07)

April 26th, 2017
by Joseph Magill

Nucleonica’s Beta Dose Rate application has been extended to include the personal dose equivalent Hp(0.07) @ 10 cm in air for over 760 beta emitting nuclides. The beta spectrum for each endpoint beta energy is used to calculate the flux at a distance of 10 cm from the source. Using the conversion coefficients (from Monte Carlo calculations) for electrons for flux to dose in air, the dose rates at a depth of 0.07 mm are calculated.
BDR_ValOf the 763 beta emitters for which data is available, there is good agreement to within 20% for 88% of all nuclides with recent literature values (Otto 2016). For 66 nuclides (8.6%) agreement is in the range 20 -100% (i.e. a factor two). For 22 nuclides there is quite a large disagreement (> factor 2).
A colour coding system has been introduced: green (good agreement within 20%); yellow (agreement to within a factor 2); and red where there are larger discrepancies. In the latter case care must be used with the values given (i.e. need to check the underlying nuclear data).

More information
Beta Dose Rate wiki page
T. Otto, Personal Dose-Equivalent Conversion Coefficients for 1252 Radionuclides, Radiation Protection Dosimetry (2016), Vol. 168, No .1, pp1-70. Link

Posted in Nucleonica | Comments

Beta Energy Spectra

April 12th, 2017
by Joseph Magill

The Beta Dose Rate application has been extended to include the beta energy spectrum using the end-point energies for all beta- and beta+ emitters. Beta spectra can be generated for both individual nuclides and nuclide mixtures.
Cl38 BetaSpectra The graph shows the spectrum for each of the three beta end-point energies for Cl-38. In addition, the sum of the spectra is also shown. It is also possible to show the end-point energies, the spectrum, and the end-point energies superimposed on the spectra.
The underlying data used in the calculations are currently from the international nuclear datafiles JEFF3.1 for ß- and 8th TORI for ß+.

More information…
Beta spectrum wiki page in Nucleonica
Reduced Decay Schemes

Posted in Nucleonica | Comments

Nucleonica Training Course, CERN, 5-6 April 2017

April 9th, 2017
by Joseph Magill

Introduction to Nucleonica: Core Applications and Tools, 5-6 April, CERN, Switzerland, 2017.
This 2-day training course took place at CERN, Switzerland, during the 5-6 April 2017. This was an introductory level training course which focused mainly on the Nucleonica core applications with emphasis on Case Studies. A detailed description of nuclear data with particular reference to the various Nucleonica nuclear databases was given. Core applications were demonstrated through the use of Nucleonica applications such as the new Radiological Converter, Nuclide Mixtures, Decay Engine++, and Dosimetry and Shielding H*(10).
CERN_April2017A key lecture was given by Mr. Yann Donjoux (CERN) on the e-Ship++ radiological transport assistant application in Nucleonica. A special session was devoted to gamma spectrometry tools including the Gamma Spectrum Generator, Gamma Library, Cambio and WESPA. The latter tools (Cambio and WESPA) were used for the identification nuclear and radioactive materials.
In total, 12 persons took part in the course from CERN.
Speakers included Mr. Y. Donjoux (CERN) in addition to Dr. J. Magill and Mr. R. Dreher from the Nucleonica team.

Posted in Nucleonica | Comments

More from this blog