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Experiments on the Synthesis of Element 113 in the Reaction 209 Bi( 70 Zn, n) 278 113

Experiments on the Synthesis of Element 113 in the Reaction 209 Bi( 70 Zn, n) 278 113 Morita Kosuke, Morimoto Kouji, Kaji Daiya*, Yoshida Atsushi, Suda Toshimi, Yoneda Akira, Haba Hiromitsu*, Ohnishi Tetsuya, Kanungo Rituparna, Katori Kenji, Akiyama Takahiro, Ideguchi Eiji,

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Experiments on the Synthesis of Element 113 in the Reaction 209 Bi( 70 Zn, n) 278 113

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  1. Experiments on the Synthesis of Element 113 in the Reaction 209Bi(70Zn, n)278113 Morita Kosuke, Morimoto Kouji, Kaji Daiya*, Yoshida Atsushi, Suda Toshimi, Yoneda Akira, Haba Hiromitsu*, Ohnishi Tetsuya, Kanungo Rituparna, Katori Kenji, Akiyama Takahiro, Ideguchi Eiji, Yamaguchi Takayuki, Goto Sin-ichi*, Kudo Hisaaki*, Ozawa Akira, Sueki Keisuke*, Koura Hiroyuki**, Zhao YuLiang*, and Xu HuShan Journal of Physical Society of Japan (JPSJ) Vol. 73, 2593 - 2596 http://www.ipap.jp/jpsj/

  2. One End of Nuclear Chart Reaction studied at GARIS 116 176 115 114 113 112 111 Ds Mt 170 48Ca induced reaction Hs Bh Sg Db Rf 162 a Lr SF No b+ or EC Md Fm b- Es Cf 152

  3. 272111 14 chains 277112 2 chains 271Ds 14 chains 265Hs 10 chains Reactions studied at GARIS 116 176 115 114 113 112 111 Ds Mt 170 Hs Bh Sg Db Rf 162 a Lr SF No b+ or EC Md Fm b- Es Cf 152

  4. 272111 14 chains 278113 271Ds 14 chains 265Hs 10 chains Reactions studied by GARIS 116 176 115 114 113 112 111 Ds Mt 170 Hs 277112 2 chains Bh Sg Db Rf 162 a Lr SF No b+ or EC Md Fm b- New ! Es Cf 152

  5. Summary 265Hs 10chains 271110 (Ds)14 chains 27211114 chains 2771122 chains 2781131 chainNew! 208Pb,209Bi(HI,1n) reaction 1mb 100nb RIKEN 10nb 1nb 100pb 10pb 1pb 0.1pb 102 104 106 108 110 112 114 100 Atomic Number

  6. Yield – Cross section Y = s×T × B × e Y= 2×10-6 /s → 1 event/6days

  7. Beam Energy Monitor GARIS RILAC Facility CSMAcc. Tanks RILAC Acc. Tanks RFQ-Linac 18GHz ECR Ion Source

  8. Required feature for a recoil separator for heavy element research • particles should be removed • beams of various charge states • target recoils • transfer products, fission fragments • come from the target • particles created at the position where the beam • and/or other particles are stopped • causes of decreasing the efficiency • charge state distribution of the ion of our interest • momentum spread of the ion • angular spread of the ion • by reaction kinematics • by multiple scattering of ion with target atoms

  9. Principle of Operation for Gas Filled Recoil Separator-I Reaction Products With Dv & Dq Br = mv/qe = 0.0227A(v/v0)/q [Tm] A: mass number v: velocity of ion v0: Bohr velocity c/137 Magnetic Field Vacuum rc qc-1 qc qc+1

  10. Principle of Operation for Gas Filled Recoil Separator-II Reaction Products With Dv & Dq Magnetic Field with qcqc+1qc+2qc+1qcqc-1qcqc-1qcqc+1qc+2 gas req qeq

  11. Principle of Operation for Gas Filled Recoil Separator-III Reaction Products With Dv & Dq Br = 0.0227A(v/v0)/q [Tm] qeq = (v/v0)Z1/3 (Bohr’s theorem) Br = 0.0227A(v/v0)/qeq Br = 0.0227AZ-1/3 [Tm] Magnetic Field with gas req qeq

  12. Gas-filled Recoil Separator GARIS B Br = m×v/q |Dr/r| = |Dm/m|+|Dv/v|+|Dq/q| in gas m << r qav: well defined → Dqav/q << 1 Br = m×v/qav detector target B：magnetic flux density m：mass of ion q：charge of ion v：velosity of ion r：radius of the ion trajectory m：mean free path of ion v0: Bhor velosity (c/137) where 1 < v/v0 < Z2/3 qav = (v/v0)×Z1/3Bhor’s Theorem Br = v0×m/Z1/3 beam

  13. RIKEN Gas-filled Recoil Separator GARIS beam Differential pumping section D1 Q1 Q2 D2

  14. 1st order Transfer Matrix of GARIS from Target to Focus x, y and l: [cm] q and f: [rad.] d: [cm/%]

  15. PSD SSD box MCP2 ions MCP1 Focal Plane Detectors

  16. New Rotating Target f = 300 mm, w = 2000 rpm cf. old one f = 125 mm, w = 1000 rpm Tested with 1pmA 86Kr beam

  17. Measurement of qeq in a helium gas

  18. 113 112 111 110 Mt Hs Bh Sg Db Rf Lr No Md Fm Es Cf Bk Cm Am Pu Np U Pa Th Ac Ra Fr Rn At Po Bi Pb

  19. detector size 245Fm FWHM = 5.3% Transmission (%) B (kGauss)

  20. 20 208Pb 18 209Bi Bohr’s theorem 16 169Tm 14 198At 271110 208Pb 12 272111 qeq 265Hs 209Bi 212Ac 10 192Bi 203Fr 8 208Pb 204Fr 234Bk 254No 6 255Lr 245Fm 209Bi 4 30 5 25 20 15 10 v0: Bohr velocity (v/v0)Z1/3

  21. Transmission v/v0

  22. Positional Distribution at Focal Plane P(He) = 67 Pa (0.5Torr) L = 500 cm

  23. Performance of detection system Beam-like particles 5 Target-like particles 0 8 9 10 11 12 256Lr 260Db 264Bh 268Mt 272111 Light charged particles TOF-energy spectrum ER-a correlation analysis 209Bi+64Ni reaction (Main.033, strip 13) Total 100 50 0.5 cps 10 1 0 5 10 15 20 25 40 272111 Total [ ROI = 8 - 12MeV ] 2.4x10-2 cps 30 Energy / MeV Counts per 10 keV 20 Anti-coincidence with TOF detectors 5 1.8x10-3 cps 10 0 8 9 10 11 12 0 ER-a correlation (DP=+/-1 mm, Dt=30 s) 0 20 40 60 80 100 5 TOF / ns 0 8 9 10 11 12 Energy / MeV

  24. 208Pb(64Ni, n)271DsExperimental condition Beam 64Ni0.4～1 pmA 310 MeV 1.0 x 1018 14 days 1 event 313 MeV 1.0 x 1018 12 days 4 event 316 MeV 1.1 x 1018 7 days 9 event 320 MeV 1.0 x 1018 7 days 0 event Total 4.1 x 1018 40 days 14 event Target 208Pb190～250mg/cm2 (98% enriched) evaporated on 30 mg/cm2 C covered by 10 mg/cm2 C Br (GARIS) 2.05 Tm P (GARIS) 75 Pa ε(GARIS) 0.8 Total Counting rate 10～20 cps

  25. a a a a a a a a a a 208Pb(64Ni,n)271Ds CN 271Ds Eproj=313MeV 2.2 ms 10.73 MeV (PSD) 26-Jul-2002 Eproj=313MeV 267Hs 68.0 ms 9.82 MeV (PSD) 25-Sep-2002 263Sg CN 271Ds 18.0 ms 8.71 MeV (PSD+SSD) 239 ms 10.71 MeV (PSD+SSD) 259Rf 267Hs 3.13 s 8.87MeV (PSD) 66.0 ms 10.09 MeV (PSD+SSD) 255No 263Sg 394.7 s s 8.07 MeV (PSD) 48.0 ms 10.83 MeV (PSD+SSD) 251Fm 259Rf 2.71s 10.46 MeV (PSD+SSD) 255No 58.4 s 7.73 MeV (PSD) 251Fm

  26. 5 5 5 5 5 0 0 0 0 0 251Fm  255No  259Rf  263Sg  267Hs  271Ds a5 a4 a3 a2 a1 t=2.9ms t=120ms 5 a1 a1 0 11 5 1000s 1ms 0.1s 10s 8 9 t=77ms a2 a2 0 5 1000s 1ms 0.1s 10s 8 9 10 11 Counts/bin t=1.0s a3 a3 Counts/100keV 0 5 1000s 1ms 0.1s 10s 8 9 10 11 t=3.7s a4 a4 0 5 1000s 1ms 0.1s 10s 8 9 10 11 t=220s a5 a5 0 1000s 10ms 1ms 0.1s 10s 7 8 9 10 11 Tdecay (sec) Ea (MeV)

  27. Excitation function of208Pb(64Ni,n)271Ds 208Pb + 64Ni → 271Ds + n RIKEN errors GSI statistical (1s) s (pb) energy loss in the target E(64Ni) /MeV (lab.)

  28. 208Pb + 64Ni → 271Ds + n

  29. Experimental condition 209Bi(64Ni,n)272111 Beam 64Ni0.7～1.8 pmA 320 MeV 2.0 x 1018 8 days 323 MeV 8.2 x 1018 34 days 326 MeV 2.5 x 1018 8 days Total 1.27 x 1019 ions 50 days Target 209Bi210～310mg/cm2 evaporated on 30 mg/cm2 C covered by 10 mg/cm2 C Br (GARIS) 2.05 Tm P (GARIS) 75 Pa ε(GARIS) 0.8 Total Counting rate 2～10 cps

  30. a a a a a a a a a a a 26-Feb-2003 CN 272111 1.42 ms 11.25 MeV (PSD) 209Bi(64Ni,n)272111 Eproj=323MeV 268Mt 36.6 ms 10.43 MeV (PSD+SSD) 26-Feb-2003 CN 272111 264Bh 4th 7.11 ms 10.82 MeV (PSD+SSD) 1.87 s 9.66 MeV (PSD+SSD) 268Mt 260Db 0.715 ms 10.28 MeV (PSD) 1.52 s 9.40 MeV (PSD) CN 272111 264Bh 256Lr 2.82 ms 11.31 MeV (LG) 0.54 s 9.57 MeV (PSD) 268Mt 260Db 44 ms 10.78 MeV (PSD+SSD) S.F. 264Bh 1.71 s 231 MeV (PSD+SSD) 0.44 s 9.58 MeV (PSD) 260Db 5th 48.46 s 8.81 MeV (PSD) 6th 256Lr 8-Apr-2003

  31. a a a a a a a a a a a a 14-Apr-2003 CN 272111 1.17 ms 10.58 MeV (LG) 209Bi(64Ni,n)272111 Eproj=323MeV 268Mt 38.33 ms 10.35 MeV (PSD) 15-Apr-2003 CN 272111 264Bh 7th 8.89 ms 10.96 MeV (PSD+SSD) 3.6 ms 9.31 MeV (PSD) 268Mt 260Db 26.18 ms 2.76 MeV (PSD)esc 4.87 s 9.01 MeV (PSD) CN 272111 264Bh 256Lr 5.11 ms 11.06 MeV (PSD) S.F. 45.84 s 8.50 MeV (PSD) 268Mt 252Md 0.97 s 208 MeV (PSD) 19.1 ms 10.43 MeV (PSD) 264Bh 1.34 s 9.50 MeV (PSD) 8th 260Db 9th 3.69 s 9.10 MeV (PSD) 256Lr 7.87 s 8.41 MeV (PSD) 16-Apr-2003 252Md

  32. 5 5 a1 a1 0 0 5 5 a2 a2 0 0 Counts / 100 keV 5 5 a3 Counts / bin a3 0 0 5 5 a4 a4 0 0 5 5 a5 a5 0 0 8 9 10 11 12 100ms 10ms 1s 100s 10000s E / MeV Tdecay α 252Md ← 256Lr ← 260Db ← 264Bh ← 268Mt ← 272111 α３ α５ α４ α２ α１ t=5.5ms α１ α１ α２ t=30ms α２ t=1.3s α３ α３ α４ α４ t=27s t=2.2s α５ t=27s α５ (sec)

  33. Excitation function of 209Bi(64Ni,n)272111

  34. Summary of 209Bi + 64Ni → 272111 + n

  35. Summary of 209Bi + 70Zn experiment period 9/5/2003 ～ 12/29/2003 Beam Energy 5.03 AMeV 348 MeV at target half depth Total Dose 1.21x1019 Target Thickness 1.37x1018 /cm2 (0.48 mg/cm2) e_GARIS 0.8 (assumption) s(1-ev.) 7.5x10-38 cm2 upper limit (1s) 1.38x10-37 cm2 Irradiation time 1390 Hours (58 Days / 74 Days) Beam Intensity 2.42x1012 /s (0.4 p-mA)

  36. 208Pb,209Bi(HI,1n) reaction 1mb 100nb 10nb 1nb 100pb 10pb 1pb present work 0.1pb 102 104 106 108 110 112 114 100 Atomic Number

  37. Experimental condition 208Pb(70Zn, n)277112 period 2004/4/2 ～ 2004/5/24 Beam Energy 346 MeV at target half depth Total Dose 4.4x1018 Target Thickness 450 μg/cm2 number of events 2 s0.44+0.59-0.29 pb Irradiation time 693 Hours (28.9 Days) Beam Intensity 1.76x1012 /s (0.3 p-mA) Total counting rate ～1 cps

  38. Observed events at RIKEN in 208Pb + 70Zn reaction Strip #8 Strip #11 34.42 MeV 23.33 mm 35.13 MeV 18.45 mm 277112 CN 277112 CN 16-April-2004 E (70Zn) = 349.5 MeV 11.09 ± 0.07 MeV 1.10 ms 23.57 mm 11.32 ± 0.04 MeV 1.22 ms 18.31 mm 273Ds 273Ds 11.14 ± 0.04 MeV 0.52 ms 23.45 mm 11.15±0.07MeV (2nd trig. PSD+SSD) 39.9 ms 20.18 mm 269Hs 269Hs 9.17 ± 0.04 MeV 14.19 s 23.34 mm 9.25 ± 0.07 MeV(PSD+SSD) 0.270 s 19.03 mm 265Sg 265Sg 8.71 ± 0.04 MeV 23.02 s 23.45 mm 8.70 ± 0.04 MeV 79.9 s 18.05 mm 261Rf 261Rf 22-May-2004 E (70Zn) = 349.5 MeV 197.3 MeV 2.97 s 23.41 mm 156.3 MeV 8.3 s 18.50 mm

  39. 32.04 MeV 18.06 mm 277112 CN Observed events at GSI in 208Pb + 70Zn reaction 11.45 MeV 280 ms 17.85 mm 24.09 MeV 26.06 mm 273Ds 277112 CN 09-Feb-1996 E(70Zn) = 343.8 MeV 11.08 MeV 110 ms 17.77 mm 11.17 MeV 1406 ms 26.03 mm 269Hs 273Ds 9.23 MeV 19.7 s 17.81 mm 11.20 MeV 310 ms 26.01 mm 265Sg 269Hs 4.60 MeV 7.4 s 17.57 mm 9.18 MeV 22.0 s 26.16 mm 261Rf 265Sg 8.52 MeV 4.7 s 17.96 mm 0.2 MeV 18.8 s 27.33 mm 257No 261Rf 05-May-2000 E (70Zn) = 346.1 MeV 8.34 MeV 15.0 s 17.91 mm 153 MeV 14.5 s 26.70 mm 253Fm

  40. 277112 t = 1.0 ms 273Ds t = 0.24 ms RIKEN GSI 269Hs t = 14 s 265Sg t = 32 s 261Rf t = 7.6 s 10ms 1000s 1ms 0.1s 10s T_decay/s

  41. 103 102 101 265Sg 257No 261Rf 269Hs 100 T_decay (s) 10-1 10-2 277112 273Ds 10-3 10-4 Neutron Number

  42. t T1/2 277112 1.0 +1.0 ms 0.69 +0.69 ms -0.3 -0.23 273Ds 0.25 +0.25 ms 0.17 +0.17 ms -0.08 -0.06 269Hs 14 +14 s 9.7 +9.7 s -5 -3.2 265Sg 32 +32 s 22 +22 s -11 -8 261Rf 7.6 +7.6 s 5.3 +5.3 s -2.5 -1.8

  43. 272Ds 20 10 273111 4 2 s (pb) 278112 1 0.5 279113 0.3 0.2 0.1 5 10 15 20 Ex of C.N. (MeV) Calculated threshold of fission after 1n emission Masses of Beams & Targets Audi & Wapstra, Nucl. Phys A565, 1 (1993) Masses of Compound Nuclei Myers & Swiatecki, Nucl. Phys. A601, 141 (1996)

  44. B + T + Ecm Sn Second chance fission sreshold Ex(CN) (A – n) + n Sn saddle point Bf Deformation A saddle point Deformation Ecm Energy diagram of 1n emission B + T

  45. Summary of 209Bi + 70Zn experiment period 2003/9/5 ～ 2004/8/1 Beam Energy 5.03 AMeV 348 MeV at target half depth Total Dose 1.7x1019 Target Thickness 1.37x1018 /cm2 (0.48 mg/cm2) e_GARIS 0.8 (assumption) s(1-ev.) 5.5x10-38 cm2 55 +154-47 fb Irradiation time 1920 Hours (80 Days / 97 Days) Beam Intensity 2.42x1012 /s (0.4 p-mA)

  46. 36.75 MeV TOF 44.61 ns 30.33 mm 209Bi + 70Zn → 278113 + n 278113 CN Strip #12 a 11.68 MeV (PSD) 344μs 30.49 mm 274111 a 11.15 MeV 6.15+5.00 (PSD+SSD) 9.26 ms 30.40 mm 270Mt a 10.03 MeV 1.14+8.89(PSD+SSD) 7.16 ms 29.79 mm 266Bh a +154 s = 55 fb -47 9.08 MeV (PSD) 2.47 s 30.91 mm 262Db 23-July-2004 18:55 (JST) E (70Zn) = 349.0 MeV 204.1 MeV(PSD) 40.9 s 30.25 mm

  47. 208Pb,209Bi(HI,1n) reaction 1mb 100nb RIKEN 10nb 1nb 100pb 10pb 1pb 0.1pb 102 104 106 108 110 112 114 100 Atomic Number

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