Download
slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Synthesis of Element 113 in the Reaction 209 Bi( 70 Zn, n) 278 113 PowerPoint Presentation
Download Presentation
Synthesis of Element 113 in the Reaction 209 Bi( 70 Zn, n) 278 113

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

78 Views Download Presentation
Download Presentation

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

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. 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/ Heavy elements synthesized by ‘Cold Fusion’ reaction

  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. 122 308 305 121 120 302 299 119 118 294 293 296 117 116 293 292 291 290 115 287 288 283 284 114 286 287 288 289 290 113 278 283 284 112 277 282 284 285 286 283 111 272 274 279 280 110 271 279 281 282 273 109 268 270 275 276 108 265 267 278 272 275 269 107 264 266 272 106 263 261 265 271 105 260 262 267 268 104 259 267 261 268 257 103 256 102 255 101 100 99 98

  4. 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

  5. 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

  6. 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

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

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

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

  10. PSD SSD box MCP2 ions MCP1 Focal Plane Detectors

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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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)

  18. 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

  19. 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)

  20. 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

  21. 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

  22. 36.47 MeV TOF 45.69 ns 30.08 mm 278113 CN a 11.52 MeV (PSD) 4.93ms 30.16 mm 274111 a 0.88+10.43=11.31 MeV (PSD+SSD) 34.3 ms 29.61 mm 270Mt a 2.32 MeV (escape) 1.63 s 29.45 mm 266Bh a 2nd chain 9.77 MeV (PSD) 1.31 s 29.65 mm 2-April-2005 2:18 (JST) 262Db 192.32 MeV(PSD) 0.787 s 30.47 mm s.f. 209Bi + 70Zn → 278113 + n preliminary

  23. 36.75 MeV TOF 44.61 ns 30.33 mm 36.47 MeV TOF 45.69 ns 30.08 mm 209Bi + 70Zn → 278113 + n 278113 CN 278113 CN a a 1st chain 11.68 MeV (PSD) 344μs 30.49 mm 11.52 MeV (PSD) 4.93ms 30.16 mm 23-July-2004 18:55 (JST) 274111 274111 a a 11.15 MeV 6.149+5.003 (PSD+SSD) 9.260 ms 30.40 mm 0.88+10.43=11.31 MeV (PSD+SSD) 34.3 ms 29.61 mm 270Mt 270Mt a a 10.03 MeV 1.136+8.894(PSD+SSD) 7.163 ms 29.79 mm 2.32 MeV (escape) 1.63 s 29.45 mm 266Bh 266Bh a a 2nd chain 9.08 MeV (PSD) 2.469 s 30.91 mm 9.77 MeV (PSD) 1.31 s 29.65 mm 2-April-2005 2:18 (JST) 262Db 262Db preliminary 204.05 MeV(PSD) 40.9 s 30.25 mm 192.32 MeV(PSD) 0.787 s 30.47 mm s.f. s.f.

  24. preliminary 278113 t = 2.6 ms 274Rg t = 21.8 ms RIKEN 270Mt t = 0.82 s 266Bh t = 1.89 s 262Db t = 20.8 s 10ms 1000s 1ms 0.1s 10s T_decay/s

  25. 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

  26. Summary • 278113 was produced by 209Bi(70Zn,n) reaction. • 278113(a)→274Rg(a)→270Mt(a)→266Bh(a)→262Db(SF) • Identification was based on • connected to the known decays 266Bh(a)→262Db(SF) • reaction energy systematics • cross section systematics • Z & A of 278113 are largest ones among the isotopes whose Z & A were determined experimentally. • N=162 shell effect • second example that a-decay chain cross the N=162 (cf. 277112).

  27. Qa/ MeV N

  28. 113 calc 112 calc T1/2 N

  29. Hindrance Factor (Texp/Tcalc) N Viola & Seaborg の現象論 a=1.81040, b=-21.7199, c=-0.26488, d=-28.1319 by Smolanczuk, Phys. Rev. C56(1997)812

  30. 104 111 106 108 110

  31. 86Kr 82Se Future plan 118 294 76Ge Cold Fusion Reaction 117 116 289 290 292 70Zn 68Zn 176 115 287 288 64Ni 114 287 288 289 286 283 113 283 284 278 112 277 283 284 285 238U + 58Fe 111 272 279 280 269 270 271 273 280 281 Ds 268 275 276 Mt 170 269 Hs 267 277 Bh 266 267 271 272 238U + 40Ar Sg 265 266 Db 267 268 232Th + 40Ar N=162

  32. 209Bi + 64Ni reaction target like 272111 projectile like Counting rate 2 – 10 cps

  33. 100 projectile like 80 277112 60 target like E/MeV 40 20 0 60 0 100 20 40 80 TOF/ns Counting rate 0.5 – 1 cps

  34. projectile target recoil compound nucleus energy separator velocity separator gas-filled separator

  35. 運動学(対称ー非対称反応)の効果

  36. 86Kr 82Se Future plan 118 294 76Ge Cold Fusion Reaction 117 116 289 290 292 70Zn 68Zn 176 115 287 288 64Ni 114 287 288 289 286 283 113 283 284 278 112 277 283 284 285 111 272 279 280 269 270 271 273 280 281 Ds 268 275 276 Mt 170 269 Hs 267 277 Bh 266 267 271 272 238U + 40Ar Sg 265 266 Db 267 268 232Th + 40Ar N=162

  37. 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

  38. 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

  39. 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

  40. 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

  41. 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

  42. 1st order Transfer Matrix of GARIS from Target to Focus x, y and l: [cm] q and f: [rad.] d: [cm/%]

  43. Measurement of qeq in a helium gas

  44. 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

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

  46. 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