Projects / Programmes
Structure of hadronic systems
January 1, 2015
- December 31, 2021
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P220 |
Natural sciences and mathematics |
Nuclear physics |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
Electromagnetic and spin structure of nucleons and nuclei, real and virtual Compton scattering, form-factors, excited states, electron screening in nuclear reactions, adaptive time-domain filtering, liquid scintillation spectrometry, environment, fuels
Researchers (22)
Organisations (2)
Abstract
In our studies of electromagnetic and spin structure of nucleons and light nuclei we will focus on 1) investigations of electromagnetic form-factors of nucleons, in particular the magnetic form factor of the neutron (GMn) at high momentum transfers; 2) investigations of deeply virtual Compton scattering (DVCS) on protons; 3) investigations of real Compton scattering at high energies of the incoming photons and high transfers of transverse momentum (-t) in order to establish or verify factorization of the matrix elements; 4) virtual Compton scattering at low momentum transfers, whence we will obtain information on generalized polarizabilities of the nucleon, and 5) studies of excited states of nucleons in the processes of electroproduction of light and strange mesons (in particular pions and kaons) to determine the corresponding electroproduction and scattering amplitudes.
In the field of our research of electron screening in nuclear reactions we will study reactions in inverse kinematics. We will continue with the already researched reaction 1H(7Li,α)4He by implanting protons into other metals that we have not yet used. Later, we are planning to study the reactions 1H(19F,αγ)16O, 2H(19F,n)20Ne and 1H(11B,γ)12C. In case we are unable to reach the desired beam energies with the Tandetron accelerator at JSI, we will try to study the planned reactions at a different accelerator abroad. The above reactions were chosen due to their large cross sections and resonance behavior. This will enable simultaneous measurements of the electron screening potential and possible shifts in resonance energy, that should reveal the influence of the nuclear environment on the atomic nucleus.
In our work on digital pulse processing we will upgrade adaptive filtering and analysis of signals from semiconductor and scintillator particle and ionizing photon detectors to
a full-bandwidth true time-domain approach by precision modeling of the series and parallel noises of the analog part of the DAQ chain.
The Laboratory for liquid scintillation spectrometry (LSC) will continue the work in already established fields (items 1-3) and new challenges (items 4 and 5):
1. development, implementation, optimization and validation of new LSC methods:
a) C-14 in waters,
b) H-3 in the form of water into organic samples, and
c) Total alpha beta emittors in water samples.
2. analyses of environmental samples and fuels,
3. interdisciplinary interpretation of results,
4. metrological investigations:
a) preparation of intercomparison samples,
b) characterization of reference materials,
5. update of database system
Significance for science
The proposed research of electromagnetic and spin structure of nucleons and light nuclei at Jefferson Lab and MAMI is at the frontline of contemporary experimental hadronic physics. The obtained experimental results will be unique, since the enumerated quantities and observables can not be measured elsewhere, as no similar facilities exist anywhere in the world. In reactions that we intend to study, we will determine fundamental quantities like elastic form-factors, polarizabilities, transition matrix elements for ground-state to excited-state transitions, cross-sections at high momentum transfers. All this will be accomplished to high statistical (and, due to our good control over the experimental apparatus and software packages, also systematic) accuracy.
Electron screening in nuclear reactions is important in various fields of research. In basic research it is important in our understanding of processes in stars, either in energy production or in explosive events that lead to the synthesis of chemical elements. It could also be important in big bang nucleosynthesis, where the problem of overproduction of lithium remains unsolved. On the other hand, electron screening could provide a handy explanation for the effect of cold fusion, if that exists.
In many in-beam experiments, be it for basic research in subatomic physics, material science or life sciences, the acquisition of detection signals turns out to be the dominant bottleneck in the measurement system. The proposed improvements in data acquisition science will likely expand this narrow passage in knowledge extraction by as much as an order of magnitude.
Optimized methods in liquid scintillation spectrometry, new approaches to data acquisition, their inventory and utilization, and new software tools will be accessible through scientific contributions to the wider professional community and indirectly to all interested users. Lower detection limits enable more comprehensive and realistic interpretation of measurement results. The proposed innovations (5 spectra instead of the 2, calibration curves based on the real samples, a non fixede energy windows) will be generally useful and interesting at determinatin of other radionuclides and matrices in liquid scintillation spectrometry.
Significance for the country
As mentioned earlier, electron screening in nuclear reactions could possibly lead to the solution of the future energy production on Earth. This would certainly benefit Slovenia, especially if it is first done here.
The laboratory for liquid scintillation spectrometry is the only place in Slovenia where tritium content in water can be measured to a sufficient precision and accuracy and with such limits of detection that the results can be used for water dating and other hydrological studies. The so-called precipitation tritium curve will allow more detailed description of the aquifers. Our services are indispensable in categorization of water bodies, at our regular customers as well as companies which bottle mineral water or manage thermal springs. We also carry out a part of the national monitoring and improved methods proposed in this program are needed also for this activity. Our LSC spectrometers, knowledge, experience and available counting time allow us to determine the content of biocomponents in fuels within the limits required by the administrative authorities (customs laboratory). Administrative authorities of other countries also contact us for the same purpose. Good results in international intercomparisons make us visible and recognizable also beyond national borders. Top level equipment allows us to implement and optimize new methods needed by the users of the Slovenian economy and other areas of research at home and abroad.
Most important scientific results
Annual report
2015,
interim report
Most important socioeconomically and culturally relevant results
Annual report
2015,
interim report
