Recent Activities For β-decay Half-lives And β-delayed Neutron Emission Of Very Neutron-rich Isotopes

被引：2

作者：

Dillmann, Iris ^{[1
]}

Abriola, Daniel ^{[1
]}

Singh, Balraj ^{[1
]}

机构：

[1] TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada

来源：

ORIGIN OF MATTER AND EVOLUTION OF GALAXIES 2013 | 2014年 / 1594卷

关键词：

Stellar nucleosynthesis; r process; neutron-rich nuclei; half-lives; neutron emission probabilities; URANIUM; RADIOACTIVITY; PROBABILITIES; EXISTENCE;

D O I：

10.1063/1.4874091

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Beta-delayed neutron (beta n) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the "rapid neutron-capture process" (r process). On one hand they lead to a detour of the material beta-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) "Terra Incognita". With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure beta n-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 beta-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 beta-delayed two-, three- or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a "Coordinated Research Project" on a "Reference Database for Beta-Delayed Neutron Emission Data". This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of beta-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and theoretical models.

引用

页码：332 / 338

页数：7

共 31 条

[1]

Abriola D., 2011, INDCNDS0599 IAEA

[2] A SEMI-EMPIRICAL TREATMENT OF NEUTRON EMISSION PROBABILITIES FROM DELAYED NEUTRON PRECURSORS [J].

AMIEL, S ;

FELDSTEIN, H .

PHYSICS LETTERS B, 1970, B 31 (02) :59-+

[3] Dynamical r-process studies within the neutrino-driven wind scenario and its sensitivity to the nuclear physics input [J].

Arcones, A. ;

Martinez-Pinedo, G. .

PHYSICAL REVIEW C, 2011, 83 (04)

[4] The AME2012 atomic mass evaluation (I). Evaluation of input data, adjustment procedures [J].

Audi, G. ;

Wang, M. ;

Wapstra, A. H. ;

Kondev, F. G. ;

MacCormick, M. ;

Xu, X. ;

Pfeiffer, B. .

CHINESE PHYSICS C, 2012, 36 (12) :1287-1602

[5] 1ST OBSERVATION OF BETA-DELAYED 2-NEUTRON RADIOACTIVITY - LI-11 [J].

AZUMA, RE ;

CARRAZ, LC ;

HANSEN, PG ;

JONSON, B ;

KRATZ, KL ;

MATTSSON, S ;

NYMAN, G ;

OHM, H ;

RAVN, HL ;

SCHRODER, A ;

ZIEGERT, W .

PHYSICAL REVIEW LETTERS, 1979, 43 (22) :1652-1654

[6] β-delayed neutron emission measurements around the third γ-process abundance peak [J].

Caballero-Folch, R. ;

Domingo-Pardo, C. ;

Tain, J. L. ;

Cortes, G. ;

Agramunt, J. ;

Algora, A. ;

Ameil, F. ;

Ayyad, Y. ;

Benlliure, J. ;

Bowry, M. ;

Calvino, F. ;

Cano-Ott, D. ;

Davinson, T. ;

Dillmann, I. ;

Estrade, A. ;

Evdokimov, A. ;

Faestermann, T. ;

Farinon, F. ;

Galaviz, D. ;

Garcia-Rios, A. ;

Geissel, H. ;

Gelletly, W. ;

Gernhaeuser, R. ;

Gomez-Hornillos, M. B. ;

Guerrero, C. ;

Heil, M. ;

Hinke, C. ;

Knoebel, R. ;

Kojouharov, I. ;

Kurcewicz, J. ;

Kurz, N. ;

Litvinov, Y. ;

Maier, L. ;

Marganiec, J. ;

Marta, M. ;

Martinez, T. ;

Montes, F. ;

Mukha, I. ;

Napoli, D. R. ;

Nociforo, C. ;

Paradela, C. ;

Pietri, S. ;

Podolyak, Zs. ;

Prochazka, A. ;

Rice, S. ;

Riego, A. ;

Rubio, B. ;

Schaffner, H. ;

Scheidenberger, C. ;

Smith, K. .

LA RABIDA 2012 INTERNATIONAL SCIENTIFIC MEETING ON NUCLEAR PHYSICS: BASIC CONCEPTS IN NUCLEAR PHYSICS: THEORY, EXPERIMENTS, AND APPLICATIONS, 2013, 1541 :137-139

[7] Possible existence of a neutron [J].

Chadwick, J .

NATURE, 1932, 129 :312-312

[8] The existence of a neutron [J].

Chadwick, J .

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-CONTAINING PAPERS OF A MATHEMATICAL AND PHYSICAL CHARACTER, 1932, 136 (830) :692-708

[9]

Dillmann I., INDCNDS0643 IAEA

[10]

Domingo-Pardo C., 2013, P NT C NUCL PHYS AST

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