Neutron dose rate app extended to reference neutron sources

December 13th, 2018
by Joseph Magill

The neutron dose rate application, previously restricted to monoenergetic neutrons, has been extended to include the spectrum averaged ambient dose equivalent coefficients for common neutron sources. This allows the user to calculate ambient dose rates for the following reference radionuclide neutron sources:
– Cf252;
– Cf252 (D2O moderated);
– Am241-B; and
– Am241-Be
NDR_2 In the example above, the neutron dose rate for 1 g Cf-252 at 1 m is 2.65e7 µSv/h and results from a neutron source strength of 2.40e12 neutrons s-1 at the source and 1.91e7 neutrons cm-2 s-1 at 1 m distance from the source.

More information…
– Neutron Dose Rate application wiki page
– Reference neutron radiations — Part 1: Characteristics and methods of production, ISO 8529-1:2001, 2001. Link. See also … link
– Neutron Shielding for a 252Cf Source. Link

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ENDF/B-VIII.0 (2018) decay data now available in Nucleonica

November 30th, 2018
by Joseph Magill

On February 2, 2018, CSEWG released its latest revision of the ENDF/B library, ENDF/B-VIII.0.
The ENDF/B-VIII.0 (2018) decay data sublibrary is now available in Nucleonica in addition to the previously used decay data library JEFF3.1, and EBDF/B-VII.1. It is now possible to compare and contrast the main European (JEFF3.1) and American (ENDF/BVII.1, ENDF/B-VIII.0) data libraries for differences in half-lives, branching ratios, energies and emission probabilities of the emitted radiations, etc. using Nucleonica’s user friendly tools. This data comparison can be accessed through the Options tab of the Nuclide Datasheets++ application.ENDFB8

More info…
ENDF/B-VIII.0
ENDF/B-VIII.0 Evaluated Nuclear Data Library

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Use of Concise Notation for Half-life Uncertainties

November 28th, 2018
by Joseph Magill

The use of the concise notation is best demonstrated with an example. Research papers often publish half-lives in so-called ‘non-concise’ form. As an example, the half-life of the alpha emitter Gd-148 has been measured to be T1/2= 70.9 ± 1.0y. When this information is published in, for example, ENSDF, NDS etc. a more concise notation is used as shown in the diagram below for Gd-148 i.e. T1/2(y) = 70.9 10 where it understood that the number in italics is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result.
Gd148 Extract from ENSDF for nuclear data on Gd-148.

As another example, the half-life of Po-209 is given in the original scientific paper as as T1/2(y) = (125.2 ± 3.3) a. In Nucleonica’s Nuclide Datasheets, however, the half-life is given as T1/2(y) = 125.2 (33) a. Notice the notation follows that of NIST which is slightly different from the ENSDF above (NIST has the uncertainty in brackets, non-italic e.g. (33); ENSDF has the uncertainty in italic withour brackets e.g. 33). Further examples of uncertainties notations are shown below.
NDS-Uncertainties For further information see the references below.

References
Use of concise notation for data uncertainties
Standard Uncertainty and Relative Standard Uncertainty
ENSDF manuel; Note on uncertainties is on page 104
NDS Notes on page 7

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How to add Nucleonica login to your smartphone/tablet homescreen

November 23rd, 2018
by Joseph Magill

Launch the mobile browser and open the website or web page you want to pin to your home screen. Use https://nucleonica.com/?login to pin the login page for fast access (If you do not see the login page, clear the cache using Ctrl+F5). Tap the menu button and tap Add to homescreen. You’ll be able to enter a name for the shortcut and then Chrome will add it to your home screen.
More information

Mobile-Nuc2On the homescreen shown above, four Nucleonica pages have been added:
1. Nucleonica Login (click on this icon to get to the login page. Click again to enter the portal, assuming username and password have been saved).
2. NucleonicaBlog (click here to go directly to the latest information on the blog)
3. Nucleonica Faqs (Click here to go directly to the Frequently Asked Questions)
4. Nucleonica Wiki (Click here to go directly to the Nucleonica wiki)

See also Nucleonica for Smartphones

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Nuclear Security training course at BfS, Berlin 2018

November 9th, 2018
by Joseph Magill

Nucleonica Training on Nuclear Security, 7-8 November, BfS Berlin, 2018
This 1-day training course took place at the offices of the Federal Office for Radiation Protection (Bundesamt für Strahlenschutz BfS) in Berlin, during the 7-8 November 2018. This was an intermediate 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 Radiological Converter, Nuclide Mixtures, Decay Engine++, and WESPA++. The new eLearning centre in Nucleonica was described.BetasinTissueSimulation of the Stopping of 500 keV beta particles in 1 mm tissue using Nucleonica’s Virtual Cloud Chamber.

A major focus of the course was on nuclear security related exercies on the identification of suspected nuclear and radioactive materials using Cambio and WESPA++.
In total, 10 persons took part in the course from the various BfS locations in Germany.

More info…
Nucleonica Training Course Proceedings

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Nucleonica Training Course, CERN, 29-30 Oct. 2018

November 5th, 2018
by Joseph Magill

Introduction to Nucleonica: Core Applications and Tools, 29-30 Oct. CERN, Switzerland, 2018.
This 2-day course 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 the Radiological Converter, Nuclide Mixtures, Decay Engine++, and Dosimetry and Shielding H*(10). The new e-Learning centre to support the Nucleonica applications was described.
IMG_20180416_144805 A key lecture with exercises was given by Mr. P. Bertreix (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.
Speakers included Mr. P. Bertreix (CERN) in addition to Dr. J. Magill and Mr. R. Dreher from the Nucleonica team.

Previous Training Courses

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Cambio++ files saved directly in WESPA++

October 19th, 2018
by Joseph Magill

Spectrum files with various data formats uploaded into Cambio++ and converted to (IAEA) .spe format can now be saved directly in WESPA++. This avoids downloading the file and then uploading again into WESPA++.
The image shows an uploaded file (ORTEC_CHN.Chn) and the converted file (ORTEC_CHN.Spe) in (IAEA) .spe format. The converted file .spe can be saved directly in WESPA++ by clicking on the Save to WESPA++ button.
CambiotoWespa
More information:
Cambio++ wiki page

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Server Issues

September 17th, 2018
by Joseph Magill

On Thursday 13 Sept. 2018, there was a complete failure of the main Nucleonica production server (www.nucleonica.com). The server and hard drives had to be completely replaced. The server was reinitialized with the latest Windows Server giving users the benefit of the latest server technology.
In the meantime all problems have been resolved. The Nucleonica Team apologizes for any inconvenience caused during the down time.

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Decay Engine++ with Source Terms

July 12th, 2018
by Joseph Magill

It is now possible to use source terms in Nucleonica’s Decay Engine++. Given the production rate(s) of the source(s) and duration in time, the activity buildup for the parent(s) and daughters (during the production time) is calculated using the Bateman equations with source term(s). At the end of the production time, the source term is switched off and the nuclides decay as described by the Bateman equations with no source(s).
As an example, consider the production of Rn212 at ISOLDE in CERN using 4 hours of beamtime. The produced Rn212 will decay to Po208 which has the potential to contaminate the accelerator.Rn212-Source

The diagram shows the buildup of Rn212 and Po208 during the 4h production period. Thereafter, the Rn212 (halflife 24 m) decays leaving the longer-lived Po208 (half-life 2.9 y) in the system.
The Decay Engine++ can also be used in the case of multiple sources. In a first step a nuclide mixture is created containing the quantities of the source components (in Bq, Ci, mole, etc.). Thereafter the Decay Engine++ is used for the mixture. When the “source rate” units are selected (e.g. Bq/s, Ci/s, mole/s etc.), the source terms are interpreted as source rates.
During the development of the Bateman solution for constant source terms, numerical instabilities were observed principally for short production and decay times typically used in practical applications. To overcome these issues a multiple precision mathematic library was introduced into Nucleonica giving the user the opportunity to select the precision of the Decay Engine++ calculations to avoid such numerical instabilities.

More information:
Nucleonica’s Decay Engine++ wiki page

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WESPA++ with new features

June 21st, 2018
by Joseph Magill

Nucleonica’s Web Spectrum Analyser (WESPA++) has been extended to include the following new features:
* 5 generic detectors from high to very low resolution are now available (HPGe, CdZnTe, LaBr3, NaI, CsI)
* A peak can be deleted from the list of identified peaks
* A peak can be added to the list of identified peaks
* Peak area and detection limit functions can be shown on the spectrum graph
* Half-life column is added into the candidate nuclide grid
PA-DL2The original spectrum (red) is shown with identified peaks (black triangles). The peak area (green) and the detection limit/threshold (blue) functions are shown superimposed on the original spectrum. The detection limit/threshold is proportional to the uncertainty in the peak area calculation. Only peaks with peak area function above the detection limit/threshold can be classified as real peaks.

In the figure above, the spectrum in red shows the peaks and the background. The green curve shows the area function for the (red) spectrum. Associated with this area function is the detection limit / threshold function in blue which is related to the uncertainty in the area calculations. Only when the green curve lies above the blue curves are real peaks to be seen (denoted by a black triangle). It may be necessary to zoom into the peak area to see the exact location of the green and blue functions.

More info…
Nucleonica’s Web Spectrum Analyser (WESPA++) wiki page
WESPA++: Web Spectrum Analyser for Nuclear and Radioactive Material Identification

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