Introduction Introduction Rapid nucleosynthesis – models and sites Rapid nucleosynthesis – models and sites R-process under high neutron environment R-process under high neutron environment Fission in the r-process Fission in the r-process (n,f)- and  -delayed fission (n,f)- and  -delayed fission fission cycling fission cycling sf – predictions sf – predictions Theoretical Abundance of heavy nuclei Theoretical Abundance of heavy nuclei Superheavy nuclei and cosmochronometers Superheavy nuclei and cosmochronometers Conclusion Conclusion Models for spontaneous fission of heavy nuclei and nucleosynthesis of cosmo-chronometers in the r-process. Panov Igor (ITEP, NGU) Panov Igor (ITEP, NGU)

s-, r- processes SHE

nucleosynthesis beyond Fe-peak – r-process and s-process

4 r-process and s-process paths r-process and s-process paths supernovae NSM J.Truran winds Nuclear data for the r-process: ~6000 nuclei are involved 900 nuclei hasT12 > 1 hour

нуклеосинтез в реакциях с нейтронами (s-процесс): Pd Ag Cd  n  <<  n n <10 12   Z=46 Z=47 Z= --

нуклеосинтез в реакциях с нейтронами (r-process): Ag Cd In  n    (s-процесс: n  <<   n n >10 22 n n <10 12   Z=47 Z=48 Z= Waiting point

SnII,  ~  exp(-t/  ),  < 10ms SnII,  ~  0 exp(-t/  hyd ),  hyd < 10ms Merging of close binaries: NSNS, NSBH high n/seeds > 150, T 9 150, T 9 < 1, Y e < 0.1 Neutrino-induced r-process 4 He(, ’ n) 3 He Explosions on the NS surface Hot -wind, high entropy wind Hot -wind, high entropy wind – thermonuclear Sne, jets ? – thermonuclear Sne, jets ? Other objects and processes? 2. Main conditions for the r-process: (seeds); free neutrons; n/seeds; freezout 2. Main conditions for the r-process: (seeds); free neutrons; n/seeds; freezout Wasserburg, G., Busso, M., & Gallino, R. 1996, ApJ, L109 2 objects /scenario: Main r-process - Weak r-process 2 objects /scenario: Main r-process - Weak r-process

weak r-process SNIa - Truran & Cowan He-flash Blinnikov, Panov, Ptytsin, Chechetkin 1995 SNII neutrino-induced r-process -Nadyozhin, Panov, Blinnikov A&A, 335, 1998 NSM-model, main r-process? Freiburghaus et al., AJL 525, 1999 NS+BH Janka, Wanajo, Blinnikov, S. I., et al. Pazh, 10, (1984) 422 Lattimer et al., AJ 213, 225 (1977)

fission 3. R-process under high neutron density environment – in NSM Observed N r

 fission  decay        P P kn (k=0,1,2,3)   Network calculations of the r-process (n,  ) (  n) 10

Nuclear data for the r-process (up to 6000 nuclei ) beta-decay,  Cross-sections and reaction rates (n,g), (n,f),.. beta-delayed processes P in, P  df spontaneous fission, sf Mass distribution of fission products Alpha-decay, Nuclear masses and fission barriers Data base of common usage JINA - Joint Institute of Nuclear Astrophysics JINA - Joint Institute of Nuclear Astrophysics

Seeger, Fowler, et al. (1965) ; Ohnishi (1977) Thielemann, Metzinger, Klapdor, Zt.Phys., A309 (1983) 301. P  df =100% Goriely et al. Astron. Astrophys. 346, 798–804 (1999) s.f. (Swiatecky) Panov et al., Nucl. Phys. A, 718 (2003) 647. (n,fission) vs P  df I.Korneev et al. NIC-2006; Astronomy Letters, 66 (2008) 131 Y ff (Z,A) Kelic, et al., Phys. Lett. B. 616 (2005) 48 Y ff (Z,A) I.V. Panov, E. Kolbe, F.-K. Thielemann, T. Rauscher, B. Pfeiffer, K.-L. Kratz. NP A 747 (2005) 633 (n,fission) (n,  ) P  df G.Martinec-Pinedo et al, Progress in Particle and Nuclear Physics, 59 (2007) 199. (n,fission) vs P  df Y.-Z. Qian, Astron. J. 569 (2002), p. L103.  induced fission Kolbe, Langanke, Fuller. Phys Rev Lett  induced fission. I. Petermann et. al. NIC-2008; G.Martinec-Pinedo et al, Progr. in Particle and Nucl. Phys., 59 (2007) : (n,fission), P  df, s.f.,  induced f. Panov et al. AA 2010 Panov et al. AA 2010 (n,fission) and (n,  ) Petermann Martinec-Pinedo Langanke Panov Thielemann SHE AA2012 Panov, I.Korneev, Yu. Lutostansky, F.-K. Thielemann. Yad.Fiz P  di fission in the r-process and rates calculations 4. fission in the r-process and rates calculations

 nf, n  and  rates comparison for U (left) and Cm (right) n , nf,  n – Hauser-Feshbach predictions ,  df, - QRPA 15

6. Fission cycling during r-process for NSM conditions 6. Fission cycling during r-process for NSM conditions (t-duration time of the r-process; t=0 - initial composition) Neutron star mergers modelling: Rosswog et al R-process: Panov I., Thielemann F.-K. AL, 30 (2004) 711

6. Fission cycling – fission fragments are involved in the r-process as new seeds

I.Petermann, A.Arcones, A.Keli´c, K.Langanke, G.Martínez-Pinedo, W.Schmidt, K-H.Hix, I. Panov, T. Rauscher, F.-K. Thielemann, N.Zinner, NIC-2008;

R=∫ i (t) / ∑ i ∫ i (t)dt

: B f Sn > 0. 20

7. Spontaneous fission rates Lg( sf ) ~ B f (Frankel&Metropolis,1947) : Lg( sf ) ~ B f (Frankel&Metropolis,1947) : Lg( sf ) = 33,3-7,77B f (exp) (1) Lg( sf ) = 33,3-7,77B f (exp) (1) Lg( sf ) =50,127-10,145B f (etfsi) (2) Lg( sf ) =50,127-10,145B f (etfsi) (2) Lg( sf ) = -1146,4 + 75,3Z 2 /A – 1,638(Z 2 /A) 2 + 0,012(Z 2 /A) 3 -(7,24 -0,095Z 2 /A)B f (3) Lg( sf ) = -1146,4 + 75,3Z 2 /A – 1,638(Z 2 /A) 2 + 0,012(Z 2 /A) 3 -(7,24 -0,095Z 2 /A)B f (3) Zagrebaev, Karpov 2012 (Swiatecki, 1957) Zagrebaev, Karpov 2012 (Swiatecki, 1957) Macro-micro model, Smolanchuk et al (4) Macro-micro model, Smolanchuk et al (4)

B f ETFSI- Mamdouh et al., NP 2001

R-process path and abundances Y A (Z,N) when duration  r ~ 10s

n n < cm -3, n  <  Squares – most abundant nuclei White dots: 10% < P  df < 90%

25 n n < 10 12, n  << 

JINR => Zagrebaev et al. Phys. Rev. C 84, (2011) A max (progenitors) ≈280

A(progenitors) ~ < 260

Final abundances Y Final abundances Y A,  R ~ 0.4 – years

Final abundance Y A when s.f. rates ~ f(B f )

Final Y A when s.f.rates - macro-micro model 30

Conclusions Conclusions It was shown that s.f. model applied to the r- process nucleosynthesis strongly influe in first turn on yields of nuclei-cosmochronometers It was shown that s.f. model applied to the r- process nucleosynthesis strongly influe in first turn on yields of nuclei-cosmochronometers Among tested models of spontaneous fission phenomenological model based on Swiatecki model and on macro-micro model predictions gave the better results in calculation of yields of nuclei–cosmochronometers Among tested models of spontaneous fission phenomenological model based on Swiatecki model and on macro-micro model predictions gave the better results in calculation of yields of nuclei–cosmochronometers Additionally to 232/235, 235/238 pairs of nuclei- cosmochronometers, pairs 232/244 or 238/244 can be considered Additionally to 232/235, 235/238 pairs of nuclei- cosmochronometers, pairs 232/244 or 238/244 can be considered The detailed investigation of decay chain is needed The detailed investigation of decay chain is needed

Thank you ! Participants for attention Participants for attention Blinnikov, Dolgov, Korneev, Thielemann for collaboration Blinnikov, Dolgov, Korneev, Thielemann for collaboration

Fission cycling – fission fragments are involved in the r-process as new seeds

B f TF Myers, Swiatecky 1999

Map of nuclei and field of rates

o - “солнечная” распространенность элементов синим цветом – расчет для сценария слияния нейтронных звезд в двойной системе ( Панов, Корнеев и Тилеманн. Письма в АЖ, т.34, 2008;)

Model, SS and Model, SS and metal-poor halo star CS