1. Common Nuclear Data Problems for Fission Cycling in r-process and Nuclear Energy S. Chiba JAEA

2. Fission (cycling) in r-process nucleosynthesis Discovery of Ｔｈ and Ｕ in metal poor stars For realistic calculation of r-process nucleosynthesis –Is there a termination point? Where is that? –Possibility of SHE generation and discovery of its relics in meteorites –Impacts on universality (56 ≦ Z ≦ 75) –Impacts on nucleo-cosmochronometers Th/Eu, U/Th, Th/Os,....

3. Supply to medium-weight region by fission, which is less sensitive to the physical conditions of r- process sites Continuous flow from the bottom S=250 132 Sn 208 Pb 238 U

4. Regions where fissions take place in terms of KTUY05

5. Competing processes in calculation of fission cycling Spontaneous fission Neutron-induced reactions –Neutron-capture and inverse reaction –Neutron-induced fission  FFMD β-decay –β-delayed fission  FFMD –β-delayed neutron emission ν-induced reactions –(ν,e - xn) reaction –(ν,f)  FFMD

6. 30y18.1y 235 U 236 U 237 U 239 U 238 U 234 U 237 Np 238 Np 239 Np 238 Pu 239 Pu 240 Pu 241 Pu 242 Pu 243 Pu 241 Am 242 Am 243 Am 244 Am 242 Cm 243 Cm 244 Cm 245 Cm 注）青字は核分裂性核種 （核分裂断面積が捕獲断面積の 3 倍以上） 2.12d 236 Np 87.8y 14.9y 6h (0.16) 242m Am 16h (0.84) 4.96h 2.36d 注）赤字は主要 MA 核種 （いずれも非核分裂性核種） 10.1h 163d 152y 注）青 → は、数日以内の 短期的崩変 2.25h 6.75d 出典） オーム社「原子力ハンドブック」および 高速炉用 ORIGEN2 断面積ライブラリ（ JENDL3.3 ） 23.5m Burn-up of Actinides in Nuclear Reactors

7. Critical mass of 235 U with various moderators 曲線上の数値は [ 減速材原子（分子）数 ]/[ 235 U 原子数 ] を表す

8. Dynamical network calculation Dynamical network calculation Terasawa et al., ApJ 562, 470(2001) originally from Prof. Meyer ?? Reaction rates –Thielamann, Caughlan-Fowler, Maleney-Fowler, Fowler-Hoyle, Rauscher, Mohr, Wagoner, Kajino-Boyd, Orito-Kajino-Mathews, Kajino- Fukugita,Ohsaki, NACRE96 Nuclear mass –Hilf-Groote-Takahashi (modified)  KTUY05 (Prog. Theor. Phys. 305 （ 2005 ） 113) β-decay rates –Klapdor  GT-2 with KTUY05 mass, including 1n emission(2007) ν-induced spallation rate (A(ν,e - xn)A') (x=0, 8) –Langanke (5 ≦ Z ≦ 100) with dumping no fission mode ⇒ β-delayed fission, spontanious fission(KTUY05) α-decay (KTUY05 mass) Data on expanding matter of SNeII : numerically read ⇒ exponential model

9. Exponential model for expanding nuclear matter c.f. General-relativistic hydro-dynamical simulation by Terasawa, Kajino, Sumiyoshi et al. (ApJ 562, 470(2001)) （ dots ） lower 2 lines : T9 upper 2 lines : density Exponential model Ye=Yp=0.427

10. Entropy-dependence of r- process abundance

11. β-delayed fission ： Bf-dependence

12. (KTUY-3MeV （ left ）、 MS96 （ right ） )

13. FFMD (Konan model): 248 Cm, 236 U

14. β-delayed fission ： FFMD-dependence

15. En J π -dependence of CN decay target Compound TS-1 TS-2 PES deformation (elongation) Ex Bn TnTn TγTγ JπJπ B fi B fo β-decay, ν- 反応

16. J π -dependence of compound formation c.s. s波s波 p波p波 d波d波

17. Decay width Brink-Axel Hill-Wheeler Optical model Target Compound Transition state

18. Fission Probability Very strong Jπ- dependence No-experimental evidence How can we verify it ？ –Various projectile ？ (d, 3 He, 18 O)

19. Level density on the saddle How to verify it ？

20. Nuclear Structure Effects ： SRM- CC 238 U + n Coupling scheme : G.S. band (0 + - 2 + - 4 + - 6 + - 8 + )+4 side bands Soft Roator Model prediction of coupling strengths OMP : E.S. Soukhovitsij, S. Chiba et al., J. Phys. G. 30, 905-920(2004). (coupled-levels)

21. Effects of low-lying levels on reaction c.s. G.S. Band

22. B n of Sn isotopes and HF, DSD c.s.

23. U 同位体の B n

24. State-dependence of DSD c.s.

25. Resonances

26. Effects of resonances on MACS

27. Summary There are many ambiguities in calculation of β- delayed fission rates, neutron-induced fission rates necessary for fission cycling –Fission barriers, level density (especially at the saddle), their J π -dependence, FFMD, deformation parameters and GDR parameters Neutron binding energies affect the relative magnitude of DSD and HF cross sections DSD c.s. is sensitive to the presence and energies of the p-states Nuclear structure (low-lying levels) is important for reaction c.s. calculation