Summary

My research grant will end tomorrow... So now I try to overview the achievements of my work in this period.

The period of my grant started in September 2013. It seems to be a long time since then (16 months), but for a researcher, and mostly for an experimentalist, time is going very fast. 16 months in experimental nuclear physics is especially a short term: sometimes we need to wait a whole year to get a beamtime at an accelerator research facility to perform our experiment, and if something happens to this quite complicated machine, we have to wait another year... Something the same happened to us a year ago in Munich as I wrote in a previous entry.

Despite of the technical problems I think this period was very successful. My research work was very productive, which is best represented by my six scientific publications in high-rank journals. I feel that I could also fulfil the requirements of dissemination as well with a couple of informative manuscripts for the open public and with this blog. Besides, I was involved "seriously" in teaching activities of the University of Debrecen. At the Informatics Faculty I was the lecturer of a course with the title "Artificial Intelligence" which is a basic course for engineers. I have also started a new special course "Experimental Planning and Data Analysis".

But the most important achievements of the research grant period is collaboration agreement and research project contract that was signed on 14th of December 2014 by MTA Atomki and ELI-NP. This contract is based on the research project that was initiated and elaborated by my research group here at MTA Atomki.  I will be one of the principal investigators of the research project. I think this research project contract both ensures our scientific contribution in the EU funded ELI-NP project in a long term and also grant a nice research fund for our scientific work.

As a summary I think that this research grant gave me an excellent support for my research and also for all the other activities during this period. This grant has a large contribution in the realization of the collaboration between ELI-NP and MTA Atomki. The benefit of having a formal collaboration with world-leading research facility is obvious....

The fission barrier of Neptunium-238

In a recent entry I have already introduced our measurement on Neptunium-238 and the first steps of the data analysis. In the last couple of weeks I could proceed so now I want to write some details about it

a) Fission probability of Neptunium-238 in the function of excitation energy. b) Sharp resonances in the fission probability and its rotational structure

In Figure (a) the data points of our measurement are indicated by blue open triangles, and open circles represent a previous, low resolution measurement. The continuous red line indicates the result of our model calculations, in which we altered the free parameters (actually the fission barrier parameters) until the theoretical line fits to the data points. As a result we got a quite good description with a triple-humped fission barrier having barrier heights of 5.5 MeV, 6.2 MeV and 6.3 MeV.

 

This result shows that the structure of Neptunium-238 and the previously examined Protactinium-232 (both odd-odd nucleus) is quite similar. The fission resonance structure which is shown in Figure (b) also supports this similarity: these resonances are in the same energy region as in the case of Protactinium-232. Actually, this means that their 3rd minimum in the potential barrier have the same depth.

The manuscript on these results have already been accepted by Acta Physica Polonica B for publication, and will be published expectedly in April.