Archive for the ‘Nucleonica’ Category

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

June 26th, 2017

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

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New Nucleonica Landing Page

June 22nd, 2017

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

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Karlsruhe Nuclide Chart Online – Literature references now available

May 31st, 2017

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

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

April 26th, 2017

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

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Beta Energy Spectra

April 12th, 2017

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

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Nucleonica Training Course, CERN, 5-6 April 2017

April 9th, 2017

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.

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Nucleonica website connection now secure.

March 28th, 2017

From 27 March 2017 the Nucleonica website connection has been made secure through the use of a SSL certificate. Access to nucleonica is now through https://www.nucleonica.com. Using the older link http://www.nucleonica.com will result in a redirection to the new secure link.
SecureN2Pages that need to transmit private information, such as credit cards, personal information and passwords, need to have a secure connection to help prevent attackers from stealing your information. (A secure connection will have “HTTPS” in the address bar, along with a green lock icon.)

More information
Insecure password warning

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Obituary Gerda Pfennig, 8.12.1930 – 16.2.2017

March 1st, 2017

Gerda Pfennig, “Mother” of the Karlsruhe Nuclide Chart, died on 16 February 2017 aged 86.
GerdaPfennigBorn on 8 Dec. 1930, Gerda Pfennig received her training in chemistry at the Fachschule Fresenius, Wiesbaden. In 1958, she joined the Institut für Radiochemie (Institute of Radiochemistry) of the Kernreaktor Bau- und Betriebsgesellschaft mbH (Nuclear Reactor Building and Operating Company) in Karlsruhe. The first edition of the Karlsruhe Nuclide Chart, printed in 1958 in the form of a wall chart, was created by Walter Seelmann-Eggebert and his assistant Gerda Pfennig. Since this first edition, Frau Pfennig has co-authored all editions of the Chart until the 9th Edition in 2015. During the period 2006-2012 Frau Pfennig was working at the European Commission’s Institute for Transuranium Elements on the 7th (2006) and 8th (2012) editions of the Chart. From 2012-2015 she was actively involved with Nucleonica GmbH on the 9th edition of the Chart. Her life was marked with a passion for music, tennis and the nuclide chart.
In the field of nuclear data Frau Pfennig was both conscientious and dedicated and an inspiration to her colleagues. We will always keep her in our memories.

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Coincidence Summing Corrections++

February 24th, 2017

True Coincidence Summation occurs when two gamma-rays are emitted during the same decay event of the nucleus, so that they appear to be emitted instantaneously. This seemingly instantaneous emission of separate gamma-rays is known as coincidence. In this situation the detector will see both of the gamma-ray energies as one larger energy deposited in the detector. A tell-tale sign of coincidence is a summation peak that appears at the combined energy of the two characteristic gamma-rays of the source.
CSC_Co60CSC2The Coincidence Summing Corrections++ application offers the possibility of calculating the coincidence summing correction factors for a large number of radionuclides and for virtually any detector and sample size, density and composition. The results are given gamma-line by gamma-line, with the unaffected lines having a correction factor of 1.

Additional information
Coincidence Summing Corrections++ wiki page

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Reduced Decay Schemes

February 23rd, 2017

The Reduced Decay Schemes is a new application for displaying the reduced decay schemes of selected nuclides.
The nuclear data contained in the nuclide boxes (in the Karlsruhe Nuclide Chart for example) is concise due to the very limited space available. In order to obtain maximum benefit from the nuclide chart, it is important to know how to interpret the box contents correctly. In the new application, the contents of the nuclide boxes are explained in detail by making reference to the nuclide reduced decay scheme in order to relate the box contents with information on energies of emitted particles with the energy levels in the nucleus in the decay scheme diagram. Additional data has been taken from the Nuclear Data Sheets and Nucleonica’s Datasheets.
RDS_K42 To improve understanding, some transitions not mentioned in the box are added and indicated as dotted lines. Corresponding data is also indicated in grey. Radiations with a low emission probability indicated by dots or brackets in the nuclide box are also drawn with dotted lines.
Additionally a gamma spectrum of the particular nuclide is shown (generated by Nucleonica’s Gamma Spectrum Generator application).

More Information…
Reduced Decay Schemes wiki page
Gamma Spectrum Generator

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