New Result in Production and Decay of an Isotope, , of the 113 th Element Kosuke Morita Superheavy Element Laboratory RIKEN Nishina Center for Accelerator-Based Science, RIKEN 12013/1/15RIBF SEMINAR

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The Periodic Table has been evolving! 32013/1/15RIBF SEMINAR

N Z Region of interest 114? ? new nuclides: ～ 40/year new element: ～ 0.3/year 42013/1/15RIBF SEMINAR

abc de f a b c d e f V= Z1Z2e 2 R Potential energy Bf: fission barrier Deformation or distance between two centers of fragments R : saddle : scission 52013/1/15RIBF SEMINAR

2013/1/156 deformation Potential energy RIBF SEMINAR

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2013/1/15RIBF SEMINAR8 spherical deformed (axially symmetric) surface energy Coulomb energy Weizsächer-Bethe  2 deformation only

deformation Energy saddle scission 9 Physics of heavy and superheavy nuclei  large scale nuclear transmutation  quantum mechanical shell effect 2013/1/15RIBF SEMINAR

Superheavy Element 10 age of the universe ～ 4.3x10 17 s 2013/1/15RIBF SEMINAR

Rg Ds Mt Hs Bh Sg Db Rf SHE A A A  -decay Spontaneous fission  + or EC decay one end of nuclear chart ’84 － ’ /1/15RIBF SEMINAR

Rg Ds Mt Hs Bh Sg Db Rf SHE A A A  -decay Spontaneous fission  + or EC decay one end of nuclear chart one end of nuclear chart /1/15RIBF SEMINAR

Main Limitations of Various Approaches to SHE Reaction ModeProj. (Aproj) LimitationHeaviest Nuclide comment (Z)(N) multiple n-capture nSF* of Fm isotopes100157maybe possible in nature (r-process) hot fusion (HI,xn);x=3-6 Ucn≥40 MeV ≤34 &48 small survival prob. (  n /  f very small) N-rich beam often improves. (cf. 48 Ca;warm fusion) cold fusion (HI,xn);x=1,2 Ucn ≤20 MeV 50-70small fusion prob. (dynamical hindrance of fusion?) transfer reaction ≤22lack of target heavier than 254 Es** *SF: spontaneous fission. cf. T 1/2 of 258 Fm 158 ≈ 400  s. ** 254 Es(Z=99): T 1/2 ≈ 276 day /1/15RIBF SEMINAR

Ring Cyclotron pamphlet 1986 First Beam Dec /1/15RIBF SEMINAR

Ring Cyclotron pamphlet /1/15RIBF SEMINAR

Ring Cyclotron pamphlet 1990 GARIS/IGiSOL RIPS /1/15RIBF SEMINAR

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GARIS, GARIS-II CL Superheavy Element Study at RIKEN RIBF Experimental setups Hot Lab /1/15RIBF SEMINAR

RILAC Facility 18GHz ECR Ion Source RFQ-Linac CSM Acc. Tanks RILAC Acc. Tanks GARIS CSM Dec. Tank /1/15RIBF SEMINAR

2013/1/15RIBF SEMINAR21 select the nuclei of our interest from the unwanted then transport to the detector chamber Experimental setup 標的（金属薄膜） incident ion beam （粒子の流れ） イオン源 加速器 分離装置 (separator) 検出器 (detectors) nucl. reaction remove electrons from neutral atoms accelerate ions using electric field information of energies or positions of incoming ions and their decay particles are transform to electric signal 18GHz ECR ion-source 理研 original RFQ-Linac GARIS

Ds Mt Hs Bh Sg Db Rf Lr No Md Es Cf Fm  SF  + or EC - Reactions studied at RIKEN-GARIS chains 271 Ds 14 chains 272 Rg 14 chains New ! 208 Pb( 58 Fe, n) 265 Hs 208 Pb( 64 Ni, n) 271 Ds 209 Bi( 64 Ni, n) 272 Rg 208 Pb( 70 Zn, n) 277 Cn 209 Bi( 70 Zn, n) Pb( 58 Fe, n) 264 Hs 206 Pb( 58 Fe, n) 263 Hs 208 Pb( 56 Fe, n) 263 Hs 208 Pb( 58 Fe, 2n) 264 Hs 248 Cm( 18 O,5n) 261 Rf 248 Cm( 22 Ne,5n) 265 Sg 248 Cm( 23 Na,5n) 266 Bh 263, 264, 265 Hs 261 Rf 265 Sg 2013/1/15RIBF SEMINAR

23 beam Differential pumping section D1 Bending angle45 degree Pole gap150 mm Radius of central ray1200 mm Maximum field1.54 T Q1, Q2 Pole length500 mm Bore radius150 mm Maximum field gradient5.2 T/m D2 Bending angle10 degree Pole gap160 mm Pole length400 mm Maximum Field1.04 T MagnificationX-0.76 Y-1.99 Dispersion0.97 cm/% Total length5760 mm Acceptance  ±68 mrad  ±57 mrad  12.2 msr Rotating Target r150 mm  2000 rpm RIKEN Gas-filled Recoil Separator GARIS D1 Q1 Q2 D2 Standard method for heavy element physics: recoil separator + position sensitive FPD 2013/1/15RIBF SEMINAR

24 MCP1 MCP2 SSD box PSD ions Focal Plane Detectors 2013/1/15RIBF SEMINAR

2013/1/15RIBF SEMINAR25 Masses of Beams & Targets Audi & Wapstra, Nucl. Phys A565, 1 (1993) Masses of Compound Nuclei Myers & Swiatecki, Nucl. Phys. A601, 141 (1996) Calculated threshold of fission after 1n emission Ex of C.N. (MeV)  (pb) 272 Ds

2013/1/15RIBF SEMINAR26 SnSn (A – n) + n A B + T B + T + Ecm SnSn saddle point Deformation BfBf Second chance fission sreshold saddle point Deformation Energy diagram of 1n emission Ecm Ex(CN)

Cold fusion: 208 Pb 209 Bi など魔法数をもつ安定な標的に相手方となるビームを照射する。 クーロン障壁近傍の入射エネルギーでは複合核の励起エネルギーが 15 ～ 20MeV 程度。複合核の脱励起の過程で 1 個ないし 2 個の中性子を出して 超重元素である蒸発残留核を生じる。核分裂との競合回数が少ない のが利点であるが積 Z 1 ・ Z 2 が大きくいわゆる融合阻害の度合いが大きい。 より中性子欠損の大きい核が合成されるため既知核へ連結することが多い。 Hot fusion ： アクチノイド標的に 48 Ca を照射する。クーロン障壁近傍の入射エネルギーでは複合核 の励起エネルギーが 35 ～ 45MeV 程度。 2 ないし 4 個の中性子を出して脱励起しする。 cold fusion に比べて標的とビームの原子番号がより非対称であるため、積 Z 1 ・ Z 2 が cold fusion に比べ小さく、いわゆる融合阻害は無いと言われている。 より中性子欠損が少ない核が合成され、 α 崩壊チェーンは中性子過剰な側に突っ込み 既知核へ到達しない。 2013/1/15RIBF SEMINAR27

Cross-section systematics and extrapolation 300 fb 400 fb 23 Na+ 248 Cm => 266 Bh+5n RIBF SEMINAR

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2013/1/15RIBF SEMINAR30 Summary of 209 Bi + 70 Zn experiment J. Phys. Soc. Jpn., Vol. 76 (2007) J. Phys. Soc. Jpn., Vol. 73 (2004) 2593 period2003/9/5 ～ 2012/8/18 Beam Energy5.03 AMeV 348 MeV at target half depth Total Dose1.35x10 20 Target Thickness1.3x10 18 /cm 2 (0.45 mg/cm 2 )  _GARIS0.8  (3-events)2.2x cm fb Irradiation time13274 Hours(553 Days) Beam Intensity2.8x10 12 /s(0.47 p-  A) J. Phys. Soc. Jpn., Vol. 81 (2012)

beamtimeirradiation time beam dose/sum number of observed events yearmonth/day[days][×10 19 ] 20039/5 - 12/ / /8 - 8/ / /20 - 1/ / /20 - 4/ / /19 - 5/ / /7 - 8/ / /7 - 10/ / / / / /14 - 5/ / /9 - 3/ / /7 - 10/ / /22 - 5/ / /2 - 12/ / /15 - 2/ / /13 - 4/ / /12 - 7/ / /14 - 8/ / Total Table I.Summary of beamtime used. 2013/1/15RIBF SEMINAR31

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2013/1/15RIBF SEMINAR Mt 266 Bh CN MeV (PSD) 344 μs mm MeV (PSD+SSD) ms mm MeV (PSD+SSD) ms mm 9.08 MeV (PSD) s mm MeV TOF ns mm 23-July :55 (JST)     1 st chain 262 Db MeV(PSD) 40.9 s mm Mt 266 Bh CN MeV (PSD) 4.93 ms mm =11.31 MeV (PSD+SSD) 34.3 ms mm 2.32 MeV (escape) 1.63 s mm 9.77 MeV (PSD) 1.31 s mm MeV TOF ns mm 2-April :18 (JST) 209 Bi + 70 Zn → n     262 Db MeV(PSD) s mm 2 nd chain s.f.  = 31 fb

RIBF SEMINAR 266 Bh 267 Bh 262 Db E SF (Daughter) [MeV] E  (Daughter) [MeV] E  (Mother) [MeV]  1-SF in (  1-  2-SF)  2-SF in (  1-  2-SF) J I H G F E  2-  3 in (  1-  2-  3)  1-  2 in (  1-  2-  3/SF)  1-  3 in (  1-  2-  3)  1-  2  1-SF C A B D a b 262 Db 258 Lr 2013/1/1534

Rg 270 Mt 266 Bh     262 Db   267 Bh 268 Bh 269 Bh 270 Bh 271 Bh S.F. 258 Lr one n evaporation five n evaporation decays observed in synthesis decays observed in the present work 209 Bi + 70 Zn → * 248 Cm + 23 Na → 271 Bh * 2013/1/1535RIBF SEMINAR

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Rg 270 Mt 266 Bh 262 Db Rg 270 Mt 266 Bh 262 Db Rg 270 Mt 266 Bh 262 Db 258 Lr 254 Md 11 22 33 44 S. F. 11 22 33 44 11 22 33 44 55 66 Jul. 23, 2004 Apr. 2, 2005 Aug. 12, ± 0.04 MeV ms ± 0.07 MeV 9.26 ms ± 0.07 MeV 7.16 ms 9.08 ± 0.04 MeV 2.47 s 204 MeV 40.9 s ± 0.04 MeV 4.93 ms ± 0.07 MeV 34.3 ms 2.32 MeV (escape) 1.63 s 9.77 ± 0.04 MeV 1.31 s 192MeV s ± 0.06 MeV ms ± 0.06 MeV 9.97 ms ± 0.07 MeV 444 ms 9.39 ± 0.06 MeV 5.26 s 8.63 ± 0.06 MeV 126 s 8.66 ± 0.06 MeV 3.78 s 2013/1/15RIBF SEMINAR37

10  s 1 ms 0.1 s 10 s 1000 s  = 2.0 ms 274 Rg  = 18 ms 270 Mt  = 0.69 s 266 Bh  = 3.0 s 262 Db  = 56 s T_decay previous N=165 N=163 N=161 N=159 N= /1/15RIBF SEMINAR38

10  s 1 ms 0.1 s 10 s 1000 s  = 2.0 ms 274 Rg  = 18 ms 270 Mt  = 0.69 s 266 Bh  = 3.0 s 262 Db  = 56 s T_decay previous N=165 N=163 N=161 N=159 N=157 present 2013/1/15RIBF SEMINAR39

崩壊時間の常用対数 2013/1/15RIBF SEMINAR40

254 Fm(Z = 100): b  = 99.94%, T 1/2 = ± h ± MeV (0.0066%), ± MeV (0.82%), ± MeV (14.2%), ± MeV (84.9%). 254 Md/ 254m Md(Z = 101): b EC = 100%/ 100%, T 1/2 = 10 ± 3 / 28 ± 8 min 258 Lr(Z = 103): b  = 97.5%. T 1/2 = –0.42 s ± MeV (20%), ± MeV (46%), ± MeV (25%), ± MeV (9%) 262 Db(Z = 105): b  /b SF = 67%/33%. T 1/2 = 34 ± 4 s ± MeV (75%), ± MeV (16%), ± MeV (9%)  5 E  = 8.63 ± 0.06 MeV  = 126 s (present)  = s  T 1/2 = –14 s (three events)  6 E  = 8.66 ± 0.06 MeV  = 3.78 s  T 1/2 = s (one events) no signal : E(X-ray of 254 Fm) max = 142 keV Energy threshold of PSD = 800 keV  7-1 E  = 7.26 ± 0.07 MeV  = 3.96 h P acc = 0.43  7-2 E  = 7.18 ± 0.06 MeV  = 6.42 h P acc = Cf (Z=98): b  = 99.92% T 1/2 = y 2013/1/15RIBF SEMINAR41

209 Bi + 70 Zn  n  4 : 266 Bh (Z = 107) 1 st E  = 9.08 ± 0.04 MeV,  = 2.47 s 2 nd E  = 9.77 ± 0.04 MeV,  = 1.31 s 3 rd E  = 9.39 ± 0.06 MeV,  = 5.26 s mean-life = s  T 1/2 = s Cf: 248 Cm + 23 Na  266 Bh + 5n 266 Bh (Z = 107) E  = 9.05 － 9.23 MeV,  > s 2013/1/15RIBF SEMINAR42

Cn Rg Ds 270 Ds 271 Ds 273 Ds Mt 268 Mt Hs 265 Hs 266 Hs 267 Hs 269 Hs 270 Hs 271 Hs Bh 262 Bh 264 Bh 266 Bh 267 Bh Sg 259 Sg 261 Sg 263 Sg Db 260 Db Rf 260 Rf 261 Rf 262 Rf Lr 257 Lr 258 Lr 259 Lr 260 Lr 261 Lr 262 Lr No 258 No 260 No 262 No Md 254 Md 259 Md 260 Md Fm 254 Fm 255 Fm 257 Fm 258 Fm 259 Fm Es 253 Es 256 Es 257 Es Cf 251 Cf 252 Cf 253 Cf 254 Cf 255 Cf 256 Cf 262 Db 264 Hs 265 Sg 266 Sg 262 Sg 260 Sg 263 Db 263 Rf 261 Db 257 Db 258 Db 257 Rf 258 Rf 259 Rf 255 Md 256 Md 257 Md 258 Md 259 No 256 Fm 253 Fm 255 No 256 Lr 257 No 254 No 252 Es 255 Es 254 ES Rg 270 Mt 266 Bh 262 Db     SF Rg 270 Mt 266 Bh 262 Db     258 Lr  254 Md  254 Fm  250 Cf Rg 279 Rg 280 Rg 281 Rg 282 Rg 274 Mt 275 Mt 276 Mt 278 Mt 270 Bh 271 Bh 272 Bh 274 Bh 266 Db 267 Db 268 Db 270 Db Lv 291 Lv 286 Fl 287 Fl 282 Cn 275 Hs 267 Rf 283 Cn 279 Ds 271 Sg 1 st event Jul nd event Apr rd event Aug 既知核種 FLNR/LLNR/GSI/LBNL 209 Bi + 70 Zn  n CN 2013/1/15RIBF SEMINAR43

Lv 291 Lv 286 Fl 287 Fl 282 Cn 283 Cn 275 Hs 267 Rf 271 Sg 279 Ds Cn Rg Ds 270 Ds 271 Ds 273 Ds Mt 268 Mt Hs 265 Hs 266 Hs 267 Hs 269 Hs 270 Hs 271 Hs Bh 262 Bh 264 Bh 266 Bh 267 Bh Sg 259 Sg 261 Sg 263 Sg Db 260 Db Rf 260 Rf 261 Rf 262 Rf Lr 257 Lr 258 Lr 259 Lr 260 Lr 261 Lr 262 Lr No 258 No 260 No 262 No Md 254 Md 259 Md 260 Md Fm 254 Fm 255 Fm 257 Fm 258 Fm 259 Fm Es 253 Es 256 Es 257 Es Cf 251 Cf 252 Cf 253 Cf 254 Cf 255 Cf 256 Cf 262 Db 264 Hs 265 Sg 266 Sg 262 Sg 260 Sg 263 Db 263 Rf 261 Db 257 Db 258 Db 257 Rf 258 Rf 259 Rf 255 Md 256 Md 257 Md 258 Md 259 No 256 Fm 253 Fm 255 No 256 Lr 257 No 254 No 252 Es 255 Es 254 ES Rg 270 Mt 266 Bh 262 Db     Rg 270 Mt 266 Bh 262 Db 258 Lr  254 Md  254 Fm  250 Cf 3 rd event Aug 既知核種 Rg 279 Rg 280 Rg 281 Rg 282 Rg 274 Mt 275 Mt 276 Mt 278 Mt 270 Bh 271 Bh 272 Bh 274 Bh 266 Db 267 Db 268 Db 270 Db FLNR/LLNR/GSI/LBNL Actinide-based, 48 Ca induced Hot fusion reactions Rg 275 Mt 271 Bh 267 Db     SF  243 Am + 48 Ca  4n Rg 276 Mt 272 Bh 268 Db     SF  243 Am + 48 Ca  3n Rg  SF  243 Am + 48 Ca  2n Rg 274 Mt 270 Bh 266 Db     SF 237 Np + 48 Ca  3n Rg  SF  249 Bk + 48 Ca  4n  Rg 278 Mt 274 Bh 270 Db     SF   249 Bk + 48 Ca  3n 209 Bi + 70 Zn  n CN 2013/1/15RIBF SEMINAR44

Lv 291 Lv 286 Fl 287 Fl 282 Cn 275 Hs 267 Rf CN Cn Rg Ds 270 Ds 271 Ds 273 Ds Mt 268 Mt Hs 265 Hs 266 Hs 267 Hs 269 Hs 270 Hs 271 Hs Bh 262 Bh 264 Bh 266 Bh 267 Bh Sg 259 Sg 261 Sg 263 Sg Db 260 Db Rf 260 Rf 261 Rf 262 Rf Lr 257 Lr 258 Lr 259 Lr 260 Lr 261 Lr 262 Lr No 258 No 260 No 262 No Md 254 Md 259 Md 260 Md Fm 254 Fm 255 Fm 257 Fm 258 Fm 259 Fm Es 253 Es 256 Es 257 Es Cf 251 Cf 252 Cf 253 Cf 254 Cf 255 Cf 256 Cf 262 Db 264 Hs 265 Sg 266 Sg 262 Sg 260 Sg 263 Db 263 Rf 261 Db 257 Db 258 Db 257 Rf 258 Rf 259 Rf 255 Md 256 Md 257 Md 258 Md 259 No 256 Fm 253 Fm 255 No 256 Lr 257 No 254 No 252 Es 255 Es 254 ES Rg 270 Mt 266 Bh 262 Db     Rg 270 Mt 266 Bh 262 Db 258 Lr  254 Md  254 Fm  250 Cf 3 rd event Aug 既知核種 Cn 278 Rg 279 Rg 280 Rg 281 Rg 282 Rg 274 Mt 275 Mt 276 Mt 278 Mt 270 Bh 271 Bh 272 Bh 274 Bh 266 Db 267 Db 268 Db 270 Db FLNR/LLNR/GSI/LBNL Actinide-based, 48 Ca induced Hot fusion reactions 249 Bk + 48 Ca  4n 243 Am + 48 Ca  2n 209 Bi + 70 Zn  n Rg  SF  Rg  SF   CN 279 Ds 271 Sg 2013/1/15RIBF SEMINAR45

46 Hindrance Factor (T exp /T calc ) Systematics by Viola & Seaborg a= , b= , c= , d= by Smolanczuk, Phys. Rev. C56(1997) Ds Hs Sg Rf 113 Rg Mt Bh neutron number /1/15RIBF SEMINAR

Program of SHE search and spectroscopy 209 Bi( 70 Zn, n) experiment completed on Oct. 1, Study 208 Pb( 76 Ge, n) (Fl) reaction (under discussion). Start 248 Cm( 54 Cr, 3n) experiment. Systematic study of 50 Ti induced hot-fusion reactions 248 Cm( 48 Ca, 3n) 293 Lv 244 Pu( 50 Ti, 3n) 291 Lv 248 Cm( 50 Ti, 3n) New isotope search of the heaviest nuclei and detailed spectroscopy with cold and hot fusion reactions. Mass measurement of the heaviest nuclei with m-TOF system coupled to GARIS (Wada-san’s group) Study of heavy ion transfer reaction with GARIS for the study of neutron rich nuclei around N=126 region. Try to measure X-ray from evaporation residues (in collaboration with W. Henning). Developing FPD detector system for  -  -e coincidence experiment /1/15RIBF SEMINAR

48 RIKEN Nishina Center H. Haba, H. Hasebe, D. Kaji, K. Katori, Y. Kudou, T. Ohnishi, K. Ozeki, K. Morimoto, A. Yoneda, A. Yoshida, Tokyo University of Science T. Sumita, K. Tanaka, J. Chiba Saitama University T. Akiyama, R. Sakai, S. Yamaki, T. Yamaguchi Tohoku University T. Suda, H. Kikunaga, T. Shinozuka JAEA H. Koura, S. Mitsuoka, K. Ooe, N. Sato, A. Toyoshima, K. Tsukada, Y. Wakabayashi Niigata University S. Goto, M. Murakami, M. Murayama, Y. Kanaya, H. Kudo, YITP Kyoto University T. Ichikawa, University of Tsukuba A. Ozawa, K. Sueki Yamagata University Y. Fujimori, K. Mayama, T. Mashiko,S. Namai, M. Takeyama, F. Tokanai, Center for Nuclear Science, University of Tokyo E. Ideguchi Osaka University Y. Kasamatsu, Y. Kitamoto, Y. Komori, T. Kuribayashi, K. Matsuo, D. Saika, A. Shinohara, T. Takabe, Y. Tashiro, T. Yoshimura Kanazawa University T. Nanri, D. Suzuki, I. Yamazaki, A. Yokoyama Collaborators ( ) 2013/1/15RIBF SEMINAR

49 Thank you very much for your kind attention! 2013/1/15RIBF SEMINAR