The last decades brought impressive progress in synthesizing and studying properties of nuclides located very far from the beta stability line. Among the most fundamental properties of such exotic nuclides, the ones usually established first are the half-life, possible radioactive decay modes, and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays are accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start being emitted from the ground state. A review of the decay modes occurring close to the limits of stability is presented. The experimental methods used to produce, identify, and detect new species and their radiation are discussed. The current theoretical understanding of these decay processes is reviewed. The theoretical description of the most recently discovered and most complex radioactive process---the two-proton radioactivity---is discussed in more detail.

Radioactive decays at limits of nuclear stability

In the first part of this review, experimental results which lead to the discovery of two-proton radioactivity are examined. Beyond two-proton emission from nuclear ground states, we also discuss experimental studies of two-proton emission from excited states populated either by nuclear β decay or by inelastic reactions. In the second part, we review the modern theory of two-proton radioactivity. An outlook on future experimental studies and theoretical developments will conclude this review.

Two-proton radioactivity

The advent and intensive use of new detector technologies as well as radioactive ion beam facilities have opened up possibilities to investigate alpha, proton and cluster decays of highly unstable nuclei. This article provides a review of the current status of our understanding of clustering and the corresponding radioactive particle decay process in atomic nuclei. We put alpha decay in the context of charged-particle emissions which also include one- and two-proton emissions as well as heavy cluster decay. The experimental as well as the theoretical advances achieved recently in these fields are presented. Emphasis is given to the recent discoveries of charged-particle decays from proton-rich nuclei around the proton drip line. Those decay measurements have shown to provide an important probe for studying the structure of the nuclei involved. Developments on the theoretical side in nuclear many-body theories and supercomputing facilities have also made substantial progress, enabling one to study the nuclear clusterization and decays within a microscopic and consistent framework. We report on properties induced by the nuclear interaction acting in the nuclear medium, like the pairing interaction, which have been uncovered by studying the microscopic structure of clusters. The competition between cluster formations as compared to the corresponding alpha-particle formation are included. In the review we also describe the search for super-heavy nuclei connected by chains of alpha and other radioactive particle decays.

Recent developments in radioactive charged-particle emissions and related phenomena

In the first part of the present review paper, experimental results which lead to the discovery of two-proton radioactivity are reviewed. Beyond two-proton emission from nuclear ground states, we also discuss experimental studies of two-proton emission from excited states populated either by nuclear beta decay or by inelastic reactions. In the second part, we review the modern theory of two-proton radioactivity. An outlook to future experimental studies and theoretical developments will conclude this review.

Radioactive ion beams of ${}^{17}\mathrm{F}$ were used to study several resonance states in ${}^{18}\mathrm{Ne}$. Clear evidence for simultaneous two-proton emission from the 6.15 MeV state $({J}^{\ensuremath{\pi}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1}^{\ensuremath{-}})$ in ${}^{18}\mathrm{Ne}$ has been observed with the reaction ${}^{17}\mathrm{F}{+}^{1}\mathrm{H}$. Because of limited angular coverage, the data did not differentiate between the two possible mechanisms of simultaneous decay, diproton ${(}^{2}\mathrm{He})$ emission or direct three-body decay. The two-proton partial width was found to be $21\ifmmode\pm\else\textpm\fi{}3\mathrm{eV}$ assuming ${}^{2}\mathrm{He}$ emission and $57\ifmmode\pm\else\textpm\fi{}6\mathrm{eV}$ assuming three-body decay. The total width of the ${1}^{\ensuremath{-}}$ state was measured to be $50\ifmmode\pm\else\textpm\fi{}5\mathrm{keV}$. Several additional resonances that decay by single proton emission were also studied.

Decay of a Resonance in 18 Ne by the Simultaneous Emission of Two Protons

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. E. Ortiz

Author Tools

Chat about Author

Papers

Decay of a Resonance in 18 Ne by the Simultaneous Emission of Two Protons