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Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 1
Neutron Capture Nucleosynthesis
Miklós Kiss
Berze High School, Gyöngyös, Hungary
Teaching Physics Innovatively
ELTE, 2015.08.17-19.
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 2
Contents
1. The Chart of nuclei
2. Neutron sources
3. The neutron capture processes
4. Competition, lifetime
5. s-process – r-process
6. The neutron
7. Our model
8. Input data
9.1 Example 1: classical s-process
9.2 Example 2: r-process
9.3 Example 3: r-process
9.4 Example 4: m-process
10. Termination of s-process?
11. The role of base time, the width of
the band
12. The role of base time, the profile
of the band
13 The role of neutron density, the
profile of the band
14. Experiences and conclusion
15. Tellurium I.
16. Tellurium II.
17. Criteria
18. Rate Analysis or a Possible
Interpretation of Abundances
19. Isotopic case
20. Isotonic case
21. What neutron density is required?
22. Final conclusions
23. References
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 3
1. The Chart of Nuclei
[Chart of Nuclides (NuDat2) National Nuclear Data Center www.nndc.bnl.gov/nudat2, Brookhaven National Laboratory]
How nuclei are formed beyond iron?
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 4
2. Neutron sources The two main processes:
and
The first process occurs in massive helium burning stars and in AGB TP, the second
occurs in AGB stars at the TDU following the TP
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 5
3. The neutron capture processes
Neutron capture
Beta decay after
neutron capture
Gamow 1948, B2FH = Burbidge, Burbidge, Fowler és Hoyle 1957
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 6
4. Competition, lifetime
Lifetime of unstable nuclei:
Time between two neutron captures:
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 7
5. s-process – r-process
data
nuclei formation in the valley of
beta stability
nuclei formation far from the
valley
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 8
6. The neutron
Half-time: 10.4 min (611±1 s)
(Average) lifetime: 15 min (881.5±1.5 s)
[K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition
(URL: http://pdg.lbl.gov)]
Classical:
Into the s-process we must involve the nuclei if the lifetime greater than ten years.
Question:
Does the neutron take part in the neutron capture process?
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 9
7. Our model
There are no previously
excluded nuclei.
All nuclei are involved.
The exclusion made by
model.
We must take into account
all data of all nuclei.
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 10
8. Input data data of 2696 nuclei (stable 178, unstable 2518)
at r-process: 5353 nuclei
half-times, decay modes, decay ratio,
neutron capture cross sections
MACS http://adg.llnl.gov/Research/RRSN/semr/30kev/rath00_7.4.30kev_calchttp://adg.llnl.gov/Research/RRSN/semr/30kev/rath00_7.4.30kev_calchttp://adg.llnl.gov/Research/RRSN/semr/30kev/rath00_7.4.30kev_calchttp://adg.llnl.gov/Research/RRSN/semr/30kev/rath00_7.4.30kev_calc
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 11
9.1 Example 1: classical s-process
Base time ~1 day, fast decaying nuclei are excluded (T < 3,75 h)
There are some r-nuclei
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 12
9.2 Example 2: r-process few initial nuclei ( 5103 ⋅ )
320
n cm105n −⋅= r-process without s-nuclei
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 13
9.3 Example 3: r-process a great many initial nuclei
45103 ⋅ , 319
n cm105n −⋅=
The s-nuclei appeared with two exceptions. These are and .
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 14
9.4 Example 4: m-process
AGB conditions, time dependent neutron density
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 15
10. Termination of s-process?
The passage is available if the
band reached
nuclei
(T = 33 s) .
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 16
11. The role of base time, the width of the band
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 17
12. The role of base time, the profile of the band
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 18
13. The role of neutron density, profile of the band
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 19
14. Experiences and conclusion
1. The formation of nuclei occur in a band
2. There are no r-nuclei (in exclusive meaning)
3. Most of s-nuclei can form in r-process
4. The bypass of bismuth is possible at medium neutron density
5. The m-process (medium neutron density) is very important
Example: Tellurium
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 20
15. Tellurium I.
Tellurium\A 120 122 123 124 125 126 128 130
Z=52 \ N= 68 70 71 72 73 74 76 78
Solar 0,09 2,55 0,89 4,74 7,07 18,84 31,74 34,08
s-process 0 19,16 5,42 28,02 8,60 34,81 2,99 0,00
m-process 0 5,36 1,29 5,90 5,65 28,51 37,10 15,20
r-process 0 0,00 0,00 0,00 5,87 0,22 22,34 70,57
Fitted 0 3,66 0,89 4,11 5,76 18,84 31,66 34,10
(In fact, only two parameters! if a = 1)
64.5% AGB
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 21
16. Tellurium II.
The AGB stars are important places of element formation
Fitting of the tellurium isotopes
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 22
17. Criteria
1. Traditional approach
"The success of any theory of nucleosynthesis has to be measured by comparison with the
abundance patterns observed in nature."
say Käppeler, Beer and Wisshak ,
that is, we need to create such model that gives back the observed abundance.
[F. Käppeler, H. Beer and K. Wisshak, s-process nucleosynthesis-nuclear physics and the
classical model: Rep. Prog. Phys. 52 (1989) 945-1013.]
2. New point of view
It seems that the reverse approach is also useful: the abundance is the preserver of the
nuclei’s formation conditions. So instead investigating whether the theoretical model fits
the observed abundance, we look for the circumstances when the observed abundance is
available.
[M. Kiss, NIC2014, http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=204]
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 23
18. Rate Analysis or a Possible
Interpretation of Abundances
We assume the equilibrium formation of the
nuclei. From the corresponding rate equations we
can get the required neutron density both in
isotopic and isotonic cases.
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 24
19. Isotopic case
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 25
20. Isotonic case
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 26
21. What is the range of the processes?
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 27
22. Final conclusions
All experienced isotope ratios can be obtained
both at K108 temperature and at K103 8⋅ temperature
at intermediate neutron density
31412
n cm1010n −−=
so the m-process and the AGB
stars are probably one of the main places of
nucleosynthesis.
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 28
23. References
[1] E. M. Burbidge, G. R. Burbidge, W. A. Fowler, and F. Hoyle (1957). "Synthesis of the Elements in Stars". Reviews of Modern Physics 29 (4): 547. Bibcode:1957RvMP...29..547B.
doi:10.1103/RevModPhys.29.547.
[2] F. Käppeler, H. Beer and K. Wisshak, s-process nucleosynthesis-nuclear physics and the classical model: Rep. Prog. Phys. 52 (1989) 945-1013.
[3] C. E. Rolfs, W. S. Rodney: Cauldrons in the Cosmos, The Univ. of Chicago Press, 1988
[4] K. Takahashi, K. Yokoi: BETA-DECAY RATES OF HIGHLY IONIZED HEAVY ATOMS IN STELLAR INTERIORS, ATOMIC DATA AND NUCLEAR DATA TABLES 36,375-409 (1987)]
[5] M. Kiss and Z. Trócsányi, “Phenomenological Description of Neutron Capture Cross Sections at 30 keV,” ISRN Astronomy and Astrophysics, vol. 2013, Article ID 170954, 8 pages, 2013.
doi:10.1155/2013/170954
[6] D Arnett: Supernovae and Nucleosynthesis, Princeton University Press, 1996
[7] J. J. Cowan and W. K. Rose: PRODUCTION OF 14
C AND NEUTRONS IN RED GIANTS, The Astrophysical Journal, 212:149-158, 1977 February 15
[8] R. A. Malaney, Heavy -element synthesis in AGB and post-AGB stars of low mass, Mon. Not. R. astr. Soc. (1986) 223, 709-725
[9] M. Lugaro, A. I. Karakas Sara Bisterzo Models and observations of the s process in AGB, PoS(NIC X)034, 2008:
[10] P. Prado, L. Dardalet, E. Heringer, C. Higgs, C. Ritter, S. Jones, M. Pignatari, M. Bertolli, P. Woodward, Falk Herwig, i process and CEMP-s+r stars NIC XIII. 2014
[11] M. Kiss, PhD Thesis/Egyetemi doktori (PhD) értekezés, Debreceni Egyetem Debrecen 2012
[12] http://www.kadonis.org/
[13] http://www.nndc.bnl.gov/astro/
[14] Kiss M., Trócsányi Z. A unified model for nucleosynthesis of heavy elements in stars, Journal of Physics: Conference Series (2010) 012024 doi:10.1088/1742-6596/202/1/012024
[15] J. D. Gilmour and G. Turner, CONSTRAINTS ON NUCLEOSYNTHESIS FROM XENON ISOTOPES IN PRESOLAR MATERIAL, The Astrophysical Journal, 657:600Y608, 2007 March 1
[16] T. Lebzelter, J. Hron, Technetium and the third dredge up in AGB stars I. Field stars, A&A 411, 533-542 (2003) doi: 10.1051/0004-6361:20031458
[17] R. A. MALANEY: Production of technetium in red giants by γ- ray-induced fission, Nature 337, 718 - 720 (23 February 1989); doi:10.1038/337718a0
[18] http://www.nndc.bnl.gov/astro/calcmacs.jsp
[19] Kadonis 1.0: http://exp-astro.physik.uni-frankfurt.de/kadonis1.0/
Neutron Capture Nucleosynthesis Kiss Miklós, Berze High School Gyöngyös Teaching Physics Innovatively ELTE, 2015.08.17-19. 29
Thank you for your attention!