Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An interesting feature of the α-preformation probability was identified by Chinese researchers

01.08.2013
Probing the preformation of the α-particle in the α-decay process is a very attractive subject in studies of nuclear structure.

Recently, this crucial α-preformation probability was empirically deduced and exhibits a new feature that had been inferred to some extent by Professor REN Zhongzhou and his group from Department of Physics, Nanjing University. This work, titled "Model-independent trend of α-preformation probability", was published in SCIENCE CHINA Physics, Mechanics & Astronomy 2013, Vol. 56(8).


Pá values for the Po and Rn isotopic chains obtained from various models, including the present and previous results of the present group. A similar variation in all curves is clearly displayed.

Credit: ©Science China Press

Dating back to the end of the 19th century, nuclear physics established itself as a field of science with the discovery of radioactivity. Since those years, α decay has always been considered the eminent topic in nuclear physics. In particular, as the dominant decay mode of superheavy nuclei, it is currently the only useful tool in the identification of any new heavy element and its isotopes.

Theoretically, the decay process is usually imagined in the Gamow picture as a preformed α cluster tunneling through the α-daughter potential barrier. Without doubt, the α-preformation probability is critical in view of nuclear structure. Nevertheless, detailed studies of this quantity provide results that remain ambiguous, despite extensive experimental investigations.

In the present work, the authors proposed an empirical formula that for the first time directly deduces the preformation factor of the αparticle from the experimental data. The α-preformation factors of 171 even-even nuclei were initially obtained that strongly confirmed the key role played by the shell effect in the formation of the α cluster during decay. The study was also extended to include heavier cluster emissions with satisfactory results. These in turn prove to a certain degree that the present analysis of the α-preformation factor is reasonable and reliable.

Interestingly, a new feature of the α-preformation probability (Pα) became evident in a further study. From a different perspective, the α-preformation probabilities for a given isotopic chain extracted from different theoretical analyses were found to have quite similar behavior when comparing the present results with other studies. Across the various studies, the relative trend in the α-preformation probabilities for an isotopic chain were actually model-independent, although the deduced values of the α-preformation factor based on the respective model differ from each other (see Figure 1). The inference is that these studies are consistent with each other despite the different theoretical models, and the present study can be taken as a certain proof of reliability of the previous theoretical results.

This study gives valuable information on the preformation probability of emitted particles in α-decay, and the new model-independent feature has been identified in detail. The researchers hope that the present investigation can be extended to a broader range of nuclei, and be used to provide clues for their follow-up work on nuclear structure.

This research was supported by the National Natural Science Foundation of China (Grant Nos. 11035001, 10975072, 10735010 and 11120101005), the National Major State Basic Research and Development of China (Grant Nos. 2010CB327803 and 2013CB834400), the Knowledge Innovative Program of the Chinese Academy of Sciences (Grant No. KJCX2-SW-N02), the Research Fund of Doctoral Point (RFDP) (Grant No. 20100091110028), the Project Funded by the Priority Academic Programme Development of Jiangsu Higher Education Institutions (PAPD), the Research and Innovation Project for College Postgraduate of Jiangsu Province (Grant No. CXZZ12¬_0031) and the Science and Technology Development Fund of Macau (Grant No. 068/2011/A).

See the article: QIAN Y B, REN Z Z*. Model-independent trend of α-preformation probability. SCIENCE CHINA Physics, Mechanics & Astronomy, 2013, 56(8):1520-1524.

Science China Press Co., Ltd. (SCP) is a scientific journal publishing company of the Chinese Academy of Sciences (CAS). For 50 years, SCP takes its mission to present to the world the best achievements by Chinese scientists on various fields of natural sciences researches.

REN ZhongZhou | EurekAlert!
Further information:
http://zh.scichina.com/english/

More articles from Physics and Astronomy:

nachricht New quantum phenomena in graphene superlattices
19.09.2017 | Graphene Flagship

nachricht Solar wind impacts on giant 'space hurricanes' may affect satellite safety
19.09.2017 | Embry-Riddle Aeronautical University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

New quantum phenomena in graphene superlattices

19.09.2017 | Physics and Astronomy

A simple additive to improve film quality

19.09.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>