Title: Alpha-decay induced shortening of fission tracks simulated by in situ ion irradiation

Abstract

The diffusion of defects (e.g., vacancies and interstitials) and elements used for dating (e.g., He and Pb) in a mineral structure is a thermal process: This is the primary assumption used to determine the age and thermal history of minerals. For instance, thermal history reconstruction, through the number and length distribution of tracks produced by spontaneous fission of ²³⁸U, is obtained by assuming a thermal event to be the only energy source for shortening of fission tracks. Here, we report a new, non-thermal energy source that induces additional shortening of fission tracks by the irradiation of alpha-recoils from the alpha-decay of ²³⁸U and ²³²Th. We simulate alpha-decay induced track-shortening by combining ion accelerator irradiations with transmission electron microscopy. This allows for the first observation of track-shrinkage during in situ ion irradiation. We show that rather than alpha-particles, alpha-recoils induce a significant shortening of fission tracks by nuclear-collisions. The shortening of track-length can be quantified as a function of alpha-decay event dose. However, apatite is less sensitive than zircon to this non-thermal process. Furthermore, the findings exemplify the interactions among different types of self-irradiation from alpha-particles, alpha-recoils and fission-fragment nuclei in single mineral grains and have important implications for the usemore » of zircon and apatite for radiometric dating and thermochronology.« less

Authors:

Li, Weixing ^[1]; Cheng, Yuanyuan ^[2]; Feng, Lei ^[3]; Niu, Jingjing ^[1]; Liu, Yingxin  ^[4];

• Search DOE PAGES for author "Liu, Yingxin"
• Search DOE PAGES for ORCID "0000-0002-0512-6409"

Skuratov, Vladimir A. ^[5]; Zdorovets, Maxim V.  ^[6];

• Search DOE PAGES for author "Zdorovets, Maxim V."
• Search DOE PAGES for ORCID "0000-0003-2992-1375"

Boatner, Lynn A.  ^[7];

• Search DOE PAGES for author "Boatner, Lynn A."
• Search DOE PAGES for ORCID "0000-0002-0235-7594"

Ewing, Rodney C.  ^[8]

• Search DOE PAGES for author "Ewing, Rodney C."
• Search DOE PAGES for ORCID "0000-0001-9472-4031"

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+ Show Author Affiliations

1. Chinese Academy of Sciences (CAS), Beijing (China)
2. Chinese Academy of Sciences (CAS), Beijing (China); China Univ. of Geosciences, Beijing (China)
3. Chinese Academy of Sciences (CAS), Beijing (China); Lanzhou Univ. (China)
4. China Univ. of Geosciences, Beijing (China)
5. Joint Inst. for Nuclear Research, Dubna (Russia); National Research Nuclear Univ. MEPhI, Moscow (Russia); Dubna State Univ., Moscow (Russia)
6. The Inst. of Nuclear Physics of the Republic of Kazakhstan, Nur-Sultan (Kazakhstan); L.N. Gumilyov Eurasian National Univ., Nur-Sultan (Kazakhstan); Ural Federal Univ., Yekaterinburg (Russia)
7. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
8. Stanford Univ., CA (United States)

Publication Date:

Wed Feb 03 00:00:00 EST 2021

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Nuclear Energy (NE)

OSTI Identifier:

1818964

Grant/Contract Number:  

AC05-00OR22725; AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Geochimica et Cosmochimica Acta

Additional Journal Information:

Journal Volume: 299; Journal ID: ISSN 0016-7037

Publisher:

Elsevier; The Geochemical Society; The Meteoritical Society

Country of Publication:

United States

Language:

English

Subject:

73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Zircon; Apatite; Fission tracks; Alpha-decay; Radiation effects