Fission research at JAEA and opportunity with J-PARC for fission and nuclear data Katsuhisa Nishio Advanced Science Research Center Japan Atomic Energy Agency Tokai, JAPAN INT 13-3, Workshop, Seattle, 14-18.Oct.2013
K. Nishio, H. Ikezoe, S. Mitsuoka, I. Nishinaka, H. Makii, Y. Wakabayashi, K. Hirose, K. Tsukada, M. Asai, Y. Nagame, A. Kimura, H. Harada A. Andreyev, D. Jenkins S. Hofmann, D. Ackermann, F.P. Heßberger, S. Heinz, J. Khuyagbaatar, B. Kindler, V.F.Comas J.A. Heredia, I. Kojouharov, B. Lommel, R. Mann, B. Sulignano, Ch.E. Düllmann, M.Schädel S. Chiba S. Antalic, S. Saro A.G. Popeko, A.V. Yeremin, A. Svirikhin A. Yakushev, A. Gorshkov, R. Graeger, A. Türler T. Ohtsuki, K. Hagino Y. Watanabe Y. Aritomo S. Yan N. Tamura, S. Goto
Fission Research Program at JAEA @ JAEA Tandem facility Fission study for heavy-element synthesis Fission of new region of chart of nuclei Multi-nucleon transfer induced fission @ J-PARC n TOF fission measurement and future
Tokai Campus, JAEA Tokyo J-PARC Tandem facility
JAEA Tandem facility 20 MV Tandem accelerator (20UR) Super-conducting Booster Liniac ECR Ion Source on the terminal Targets :Th,U,Np,Pu,Am,Cm,Cf
Fission Study for Heavy Element Synthesis How to determine fusion probability
Super-heavy Nuclei Proton 陽子数 Number Z 120 115 110 105 100 Cold Fusion (GSI,RIKEN) Pb, Bi Targets 162 108 Sg Db Bh Ds Mt Hs Rg 113 Cn 48 Ca + Actinide Target Nuclei (FLNR) 120 118 Missing Region Deformed Shell Heavier Element Spherical Shell 184 114 Using Radioactive Nuclei ± sf EC ² - 150 155 160 165 170 175 180 185 Neutron 中性子数 Number N Understanding for fusion using actinide target nuclei are important to explore SHN
Three steps for heavy-element synthesis 34 14 S + 238 92 U 272 108 Hs* 268 108 Hs + 4 1 0 n (1) Contact (2) Fusion CN (3) Evaporation 6.6 10 12 Quasifission 3.0 10 11 Fusion- Fission 1 atom 6.3 10 12 ~ 3 10 11 Fusion probability
Fusion-fission and Quasi-fission Proton 78 Ni 132 Sn 238 U Neutron 208 Pb 274 Hs (Z=108) Potential Energy 50 0-50 -100-150 0 1 Compund Nucleus 2 3 Fusion - -0.5 36 S 0 0.0 0.5 238 U Quasi-fission + Potential by Y. Aritomo
In-Beam Fission Measurement 30 Si, 31 P, 36,34 S, 40 Ar, 40,48 Ca Beams 200 mm 120 mm Fission Fragment 1 MWPC1 238 U Fission Fragment 2 MWPC2 Multi-Wire Proportional Counter 238 U target 5 mm
Folding Angle Distribution 30 Si + 238 U Events Events 10 3 E lab =179.0 MeV 10 2 10 1 10 0 10 3 E lab =173.4 MeV 10 2 10 1 10 0 10 3 E lab =167.8 MeV 10 2 10 1 10 0 10 3 10 2 E lab =162.2 MeV 10 1 10 0 10 3 E lab =156.5 MeV 10 2 10 1 10 0 10 3 E lab =150.9 MeV 10 2 10 1 10 0 10 3 E lab =145.3 MeV 10 2 10 1 10 0 10 3 E lab =140.8 MeV 10 2 10 1 10 0 100 110 120 130 140 150 160 170 180 190 200 θ fold (deg) Folding angle, fold Beam FF 1 FF 2 fold Beam FF 1 FF 2 fold Full Momentum Transfer Fission 268 Sg Nucleon-transfer Induced Fission Beam-like 238 U-like
Fission Fragment Mass Distributions Cross section to produce fragments (mb) Fragment Mass Quasifission K. Nishio et al., Phys. Rev. C, 77, 064607 (2008). K. Nishio et al., Phys. Rev. C, 82, 044604 (2010). Excitation Energy of CN High Incident Energy 238 U Low Incident Energy
Potential Energy (MeV) 50 0-50 -100-150 Dynamical calculation of nuclear shape Fluctuation dissipation model - 0 272 Hs CN Fission Fusion 238 U Quasifission Langevin Equation 34 S Two center shell model ( 3 dimension ) 1 0.5 2 3-0.5 0.0 V. Zagreabev, J. Phys. G, 31, 825 (2005). Y. Aritomo et al., Nucl.Phys. A753, 152 (2005). Y. Aritomo, Phys.Rev.C, 80, 064604 (2009).
Shape evolution (polar collision) 30 Si + 238 U CN Y. Aritomo et al., Phys. Rev. C 85, 044614 (2012). 36 S + 238 U CN 0 5 5 10 10 30 30 50 > 50 Time ( 10-21 s )
Fusion probability Histogram All Fission Fragments Filled Area Fusion-Fission Experimental Data Fusion Probability Cross section (mb/2u) 30 Si + 238 U 34 S + 238 U 46 % 15 % 41 % 37 % 33 % 29 % 11 % 263 Sg 67 pb 7.5 % 4.9 % 264 Sg 10 pb 3.6 % c.m. Energy (MeV) 267 Hs 1.8 pb 268 Hs 0.54 pb Mass Mass K. Nishio et al., PRC 82, 024611 (2010). K. Nishio et al., PRC 82, 044604 (2010).
Fusion and ER cross sections 30 Si + 238 U Fission Cross section (mb) Evaporation Residue Cross section (mb) Excitation E energy Qasifission 10 pb Energy in c.m. (MeV) 34 S + 238 U Fission cross section (mb) Evaporation Residue Cross section (mb) Excitation energy Quasifission 67 pb 0.54 pb 1.8 pb Energy in c.m. (MeV) Capture Cross Section Fusion Probability Fusion Cross Section Survival Probability (Statistical Model ) Cross sections for SHN K. Nishio et al., PRC 82, 024611 (2010). K. Nishio et al., PRC 82, 044604 (2010).
Fission of New Region of Chart of Nuclei Appearance of a new shell in fission
Calculated by P. Moller (LANL) and J. Randrup (LBNL) Perspectives in Nuclear Fission, (Tokai 2012) Predicted Fission Fragment Mass Distributions 180 Hg 180 Hg 100 193* Ir 80 A. Andreyev et al., PRL, 105 (2010) 252502.
p + 197 Au 198 Hg* Present (E p =31.1MeV) Itkis (E p =30.0MeV)
Fission Q-value 300 Saddle Point Shape Q-value for Fission (MeV) 250 200 150 100 50 0 2010 Present 1980 258 Fm 236 U 180 Hg 193 Ir 160 Gd 124 Sn 258 Fm 238 U 193 Ir 160 Gd -50 20 40 60 80 100 120 140 160 180 200 Fragment Mass (u)
Multi-nucleon transfer Induced Fission ( Surrogate Reaction ) Fission of neutron-rich nuclei Nuclear data ( Ã, Y(m), ½ )
Multi-nucleon Transfer Reaction 16 O 16 O 18 O 238 U 240 U * Fragment 2 Fragment 1 n 239 U ( T 1/2 =23.5m) 22
Experimental Setup MWPC3 MWPC1 Target 18 O Fragment 2 18 O Beam 238 U θ LAB ΔE-E ΔE = 75μm E = 300μm 240 U* Fragment 1 16 O MWPC4 MWPC2
Particle Identification de (MeV) 18 O + 238 U (E beam =157.5 MeV ) 100 80 60 40 237-240 U 239-242 Np 241-245 Pu Am Pa Coincided with Fission Fragment F 16-19 O 14-17 N 240,239,238,237 U * n + 239 U (23.5 min) n + 237 U (6.8 day) 242,241,240,239 Np * n + 241 Np (13.9 min) n + 240 Np (65 min) n + 239 Np (2.4 day) n + 238 Np (2.1 day) 20 0 50 100 150 200 E (MeV) B 11-15 C 245,244,243,242,241 Pu * n + 243 Pu (4.9 hr) n + 241 Pu (14 yr)
235 U( 18 O, 16 O) 237 U * Fission Probability of 240 U * Events / 0.5 MeV Events / 0.5 MeV Fission Probability 6000 4000 2000 0 5 10 15 20 25 900 600 300 0 5 10 15 20 25 0.4 0.3 0.2 0.1 B f 2 nd 3 nd 0 5 10 15 20 25 0 10 20 Excitation Energy (MeV) Spectrum for 16 O Coincidence between 16 O and fission fragments Fission Probability
Fission fragment mass distribution 239 Np * Preliminary Excitation energy (MeV) Yield (%) Fragment Mass (u) Fragment Mass (u)
Excitation Energy (MeV) 237U* 239Np* 241Pu* 238U* 239U* 240U* 240Np* 241Np* 242Np* 242Pu* 243Pu* Fragment Mass (u) 244Pu*
Prompt Neutron Multiplicity in Fission Pulse Shape neutron gamma Neutron Detectors (Liquid Scintilator) Pulse Height
Summary In beam fission experiment can be used to estimate the fusion probability for heavy-element synthesis. Using multi-nucleon transfer reactions, nuclear data can be obtained for more than 10 actinide nuclei.
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