SHE Research at RIKEN/GARIS

Kosuke Morita

Research Group for Superheavy Element, RIKEN Nishina CenterDepartment of Physics, Kyushu University,

RIKEN

Kyushu Univ.

2015/11/09 JCNP2015@OSAKA 1

RCNP

2015/11/09 2JCNP2015@OSAKA

3

120

119

118

117

116

115

114

113

112

Rg

Ds

Mt

Hs

Bh

Sg

Db

Rf

162 184

262

266

265264

262

261

261

260259

258

257 258 260259

260 261 262

263

262261

SHE

A

A

A

a-decay

Spontaneous fission

b+ or EC decay

one end of nuclear chart ’84 －’ 94

2015/11/09 JCNP2015@OSAKA

4

120

119

118

117

116

115

114

113

112

Rg

Ds

Mt

Hs

Bh

Sg

Db

Rf

162 184

262

266

265264

262

261

261

260259

258

257 258 260259

260 261 262

263

262261 263

265 266

267266

259

264

269 270 271

267266

262

272

268

269 270 271

277

278

273

274

261

270

265

263

264

267

267 268

268

271 272

271

275 276

275

279 280

279

278

281

284 285 286

282

282

283 284

283

287 288 289 290286

287 288

290 291 292 293

294

SHE

A

A

A

a-decay

Spontaneous fission

b+ or EC decay

263

278

274

270

294293

290289

286285

282281

one end of nuclear chart 2010

2015/11/09 JCNP2015@OSAKA

Main Limitations of Various Approaches to SHE

Reaction Mode Proj. (Aproj)

Limitation Heaviest Nuclide

comment

(Z) (N)

multiplen-capture

n SF* of Fm isotopes 100 157 maybe possible in nature (r-process)

hot fusion(HI,xn);x=3-6Ucn≥40 MeV

≤34&48

small survival prob.(Gn/Gf very small)

118 177 N-rich beam often improves.(cf. 48Ca;warm fusion)

cold fusion(HI,xn);x=1,2Ucn ≤20 MeV

50-70 small fusion prob.(dynamical hindrance of fusion?)

113 165

transferreaction

≤22 lack of target heavier than 254Es**

103 159

*SF: spontaneous fission. cf. T1/2 of 258Fm158 ≈ 400 ms.

**254Es(Z=99): T1/2 ≈ 276 day

52015/11/09 JCNP2015@OSAKA

2015/11/09 6

Linear Accelerator Facility

18GHz ECR Ion Source

RFQ-Linac

CSM　 Acc. Tanks RILAC Acc. Tanks

GARIS

Beam Energy Monitor

JCNP2015@OSAKA

2015/11/09 7

beamDifferential pumping section

D1

Bending angle 45 degreePole gap 150 mm

Radius of central ray 1200 mm

Maximum field 1.54 T

Q1, Q2

Pole length 500 mm

Bore radius 150 mm

Maximum field gradient 5.2 T/m

D2

Bending angle 10 degree

Pole gap 160 mm

Pole length 400 mm

Maximum Field 1.04 T

Magnification X -0.76Y -1.99

Dispersion 0.97 cm/%Total length 5760 mmAcceptance Dq ±68 mrad

Df ±57 mradDW 12.2 msr

Rotating Targetr 150 mmw 2000 rpm

RIKEN Gas-filled Recoil Separator GARIS

D1 Q1 Q2 D2

JCNP2015@OSAKA

11

1110

10

10

9

9

9

9

98

8

8

7

a1

a2

a3

a4

a5

11

11

1110

8

8

Ea (MeV)

5

0

5

0

5

0

5

0

5

0

Coun

ts/1

00ke

V

a1

a2

a3

a4

a5

Tdecay

Coun

ts/b

in 01000s10s0.1s1ms

5

05 1000s10s0.1s1ms

1000s10s0.1s1ms

1000s10s0.1s1ms

1000s10s0.1s1ms

5

0

5

0

5

0

10ms

a b

t=2.9ms t=120ms

t=77ms

t=1.0s

t=3.7s

t=220s

208Pb + 64Ni 272Ds*

271Ds

267Hs

263Sg

259Rf

255No

2015/11/09 JCNP2015@OSAKA 8

GSI/SHIPLBNL/BGSIMP/GFRS

2015/11/09 JCNP2015@OSAKA 9

2015/11/09 JCNP2015@OSAKA 10

NN2003 at Moscow 18Jun2003

Nuclei n T1/2

271110 11 1.63+0.44-0.29

ms improved

271m110 3 69+56-21

ms confirmed

267Hs 12 52+13- 8

ms improved

267mHs 1 0.80+3.8-0.38

s possible

Eopt(64Ni) = 314 MeV

Eopt(cm) = 240 MeV

Summary of 208Pb + 64Ni → 271110 + n reaction

K. Morita et al., EPJA 21, 257-263 (2004)2015/11/09 JCNP2015@OSAKA 11

0

5

0

5

0

5

0

5

0

5

Coun

ts /

bin 0

5

0

5

0

5

Coun

ts /

100

keV

E α / MeV

0

5

8 9 10 11 120

5

a1

a2

a3

a4

a5

a1

a2

a3

a4

a5

10000s100s1s10ms100ms

Tdecay

254Md ← 256Lr ← 260Db ← 264Bh ← 268Mt ← 272Rg

t=5.5ms

t=30ms

t=1.3s

t=8.2s

t=26s

2015/11/09 JCNP2015@OSAKA 12

8 9 10 11 12

1

2

7

9

12

14

3

4

5

6

8

10

11

13

272111268Mt

264Bh260Db256Lr

(e)F

(e)(e)

F

F

E (MeV)

48.5 s

21.0 s

0.33 s

1.91 s

2015/11/09 JCNP2015@OSAKA 13

NN2003 at Moscow 18Jun2003

RIKEN GSI

Nuclei n T1/2

Ea Efiss. n T1/2Ea

MeVMeV

272111 14 3.8+1.4- 0.8

ms 10.2~11.56 6 1.6+1.1-0.5

ms 10.8~11.05

268Mt 14 21+8- 5

ms 9.4~10.77 6 42+29-12

ms 10.1~10.3

264Bh 14 0.89+0.31- 0.19

s 8.86~9.83208206

6 1.0+0.7-0.3

s 9.1~9.6

260Db 12 5.7+2.3- 1.3

s 8.35~9.4 231 6 2.6+1.8-0.8

s 9.1~9.2

256Lr 8 18+10- 5

s 8.35~8.65 4 33+27-10

s 8.4~8.5

Eopt(64Ni) = 319 MeV

Eopt(cm) = 244 MeV

Summary of 209Bi + 64Ni → 272111 + n reaction

K. Morita et al., JPSJ 73, 1738-1744 (2004)2015/11/09 JCNP2015@OSAKA 14

ref.1 Hofmann S. et al., Z. Phys. A354, 229 (1996) 208Pb + 70Zn → 277Cn + n2 Hofmann S. and Münzenberg G., Rev. Mod. Phys. 72, 733 (2000) 208Pb + 70Zn → 277Cn + n3,4 J. Phys. Soc. Jpn., Vol. 76, No. 4, p.043201(2007) 208Pb + 70Zn → 277Cn + n

present 208Pb + 70Zn → 277Cn + n5 Lazarev Yu. A. et al., Phys. Rev. C54, 620 (1996) 244Pu + 34S → 273Ds + 5n6 Lazarev Yu. A. et al., Phys. Rev. C62, 064307(2000) 244Pu + 22Ne → 261Rf + 5n

GSI RIKEN FLNRref. 1 2 3 4 present 5 6

277Cn 11.45 11.17 11.09±.07 11.32±.04 11.07±.070.28 ms 1.41 ms 1.10 ms 1.22 ms 0.37 ms

273Ds 11.08 11.20 11.14±.04 11.15±.07 11.03±.07 11.350.11 ms 0.31 ms 0.52 ms 0.04 ms 0.373 ms 0.39 ms

269Hs 9.23 9.18 9.17 ｃ 9.25±.07 9.14±.0419.7 s 22.0 s 14.2 s 0.27 s 36.01 s

265Sg 4.60 0.20 8.71±.04 8.70±.04 8.66±.07 8.637.40 s 18.8 s 23.0 s 79.9 s 13.84 s 158 s

261Rf 8.52 153 197 156 176 8.30±0.064.70 s 14.5 s 2.97 s 8.30 s 3.73 s 54+8

-4 s257No 8.34 8.22 8.24, 8.34

15.0 s 384 s 17 s

15

Cn

2015/11/09 JCNP2015@OSAKA

10ms 1ms 0.1s 10s 1000s

277Cn t = 0.86+0.69-0.26 ms

273Ds t = 0.27+0.22-0.08 ms

269Hs t = 18+15-6 s

265Sg t = 29+23-9 s

261Rf t =6.8+5.5-2.1 s

T_decay/s

RIKEN

GSI

N=165

N=163

N=161

N=159

N=157

RIKEN present

162015/11/09 JCNP2015@OSAKA

2015/11/09 JCNP2015@OSAKA 17

2015/11/09 18

278113

274111

270Mt

266Bh

CN

11.68 MeV344　 μs30.49 mm

11.15 MeV9.260 ms30.40 mm

10.03 MeV 7.163 ms29.79 mm

9.08 MeV2.469 s30.91 mm

36.75 MeV30.33 mm

23 July 2004, 18:55

a

a

a

a

The first observation

262Db

204.05 MeV40.9 s30.25 mm

278113

274111

270Mt

266Bh

CN

11.52 MeV4.93　 ms30.16 mm

11.31 MeV34.3 ms29.61 mm

2.32 MeV (escape)1.63 s29.45 mm

9.77 MeV1.31 s29.65 mm

36.47 MeV30.08 mm

2 April 2005, 2:18

209Bi + 70Zn → 278113 + n

a

a

a

a

262Db

192.32 MeV0.787 s30.47 mm

The second observation

s.f.s.f. JCNP2015@OSAKA

2015/11/09 JCNP2015@OSAKA 19

12 Aug. 2012The third observation

278113

274Rg

270Mt

266Bh

CN

11.82 MeV667 μs

10.65 MeV9.97 ms

10.26 MeV444 ms

9.39 MeV5.26 s

262Db

8.63 MeV126 s

258Lr

8.66 MeV3.78 s

α1

α2

α3

α4

α5

α6

254Md

266Bh0.6 s

α 9.29

SF (64%)

α (34%)262Db34 s

8.678.538.45

258Lr3.9 s

8.6548.6218.5958.565

Wilk et al., PRL 85, 2697 (2000).

Table of Isotopes, 8th ed. (1996).

254Md

α

• 6 (7) consecutive α decays

• reached to known 266Bh ， 262Db ， 258Lr

⇒ well confirm the 2004, 2005 events

Known nuclides

2015/11/09 JCNP2015@OSAKA 20

113

112 277Cn

111 272Rg

110 269Ds 270Ds 271Ds 273Ds

109 266Mt 268Mt

108 263Hs 265Hs 266Hs 267Hs 269Hs 270Hs 271Hs

107 261Bh 262Bh 264Bh 266Bh 267Bh

106 258Sg 259Sg 261Sg 263Sg

105 259Db 260Db

104 256Rf 260Rf 261Rf 262Rf

103 255Lr 257Lr 258Lr 259Lr 260Lr 261Lr 262Lr

102 256No 258No 260No 262No

101 253Md 254Md 259Md 260Md

100 252Fm 254Fm 255Fm 257Fm 258Fm 259Fm

99 251Es 253Es 256Es 257Es

98 250Cf 251Cf 252Cf 253Cf 254Cf 255Cf 256Cf

262Db

264Hs

265Sg 266Sg262Sg260Sg

263Db

263Rf

261Db257Db 258Db

257Rf 258Rf 259Rf

255Md 256Md 257Md258Md

259No

256Fm253Fm

255No

256Lr

257No254No

252Es 255Es254ES

278113

274Rg

270Mt

266Bh

262Db

a

a

a

a

SF

278113

274Rg

270Mt

266Bh

262Db

a

a

a

a

258Lr

a

254Md

a

254Fm

a

250Cf

1st event Jul. 23 20042nd event Apr. 2 20053rd event Aug. 12 2012

既知核種

209Bi + 70Zn n

2015/11/09 21

観測された崩壊のまとめ

JCNP2015@OSAKA

RIKEN K. Morita, K. Morimoto, D. Kaji, H. Haba, K. Okeki, Y. Kudo, Y. Wakabayashi, A. Yoneda, A. Yoshida, T. Onishi, Y. Kasamatsu,H. Hasebe, M. Huang, T. Ichikawa, R. Kanungo, K. Katori

Tokyo U. of Physics T. Sumita, K. TanakaSaitama U. T. Yamaguci, T. Akiyama, R. Sakai, S. YamakiNiigata U. H. Kudo, S. Goto, M. Murakami, H. murayama, Y. KariyaIMP Lanzhou H.-S. Xu ， T. HuangU. Tokyo E. IdeguchiTohoku U. T. Suda, H. KikunagaJAEA N. Sato, H. Koura, S. MitsuokaYamagata U. F. Tokanai, T. Moriya, K. Mayama, M. Takeyama, S. Namai,

A. MashikoU. Tsukuba A. Ozawa, K. Sueki高能物理研究所 Y.-L. Zhao

Journal of the Physical Society of Japan, 73 (2004) 1593 – 1596.Journal of the Physical Society of Japan, 76 (2007) 045001.Journal of the Physical Society of Japan, 81 (2012) 103201.

Elm. 113

2015/11/09 JCNP2015@OSAKA 22

248Cm + 48Ca 296Lv* Experiment at RIKEN GARISDec. 1 - 12, 2013, Sep. 19 – Oct. 16, 2014

RIKEN D. Kaji, K. Morimoto, H. Haba, Y. Wakabayashi, M. Huang, J. Kanaya, A. Yoneda, A. Yoshida, K. Katori

Tokyo U. Sci. K. TanakaYamagata U. M. Takeyema, F. Tokanai, T. YoshidaSaitama U. S. Yamaki, T. YamaguchiNiigata U. M. MurakamiIMP Lanzhou Z. Gan, L. MaGSI H. Geissel, S. Hofmann, Y. Maurer, S. Heinz Kyushu U. K. Morita, K. Fujita, Y. Narikiyo, T. Tanaka, S. Yamamoto

2015/11/09 JCNP2015@OSAKA 23

Date Time/days

D(Ti)/mgcm-2

D(Cm)/mgcm-2

E(RILAC)MeV

Elab/MeV (b – c – e)

Ip/pmA

Dose/1018

Ex_296Lv/MeV

2/12 – 12/122013

10 0.90 0.265 262.0 251.0 - 250.0 - 249.0 800 4.3 41.5±1.0

19/9 – 16/102014

14.2 0.90 0.290 258.0 247.0 - 246.0 - 245.0 680 5.0 37.5±1.1

Sep. Oct.2015

0.9 0.220 266.7 254.3 44

RIKEN/GARIS

2015/11/09 JCNP2015@OSAKA 24

Ex_296Lv/MeV

Correlated events(decay chains)

41.5±1.0 3 (4n), 1 (3n), 1(3n?) tentative

37.5±1.1 1 (3n), 1 (3n?) tentative

44 0 preliminary

2015/11/09 JCNP2015@OSAKA 25

Summary

An isotope of the 113th element, 278113, was produced in the 209Bi + 70Zn 278113 + n reaction, and unambiguously identifiedvia genetic correlation, connected to the well known nuclides.

293Lv and 292Lv were produced in the 248Cm + 48Ca 296Lv* reaction

What’s Next (New Element Search) ?

294118

293117 294117

292Lv 293Lv 294Lv291Lv290Lv

295118

N = 174 175 176 177 178

2015/11/09 JCNP2015@OSAKA 26

Systematic study of the actinide based 50Ti -induced reactions.

248Cm + 50Ti 298118180*cf. 249Cf + 48Ca 297118179*

Future ?248Cm + 54Cr 302120182*

Study of new reaction mechanism (non-complete fusion) to produce SHE such as multi-nucleon transfer, or deep inelastic reaction of 248Cm + 238U?

Breakthrough is needed!

Spectroscopic studies of the isotopes of the heaviest element.Chemistry of superheavy Element.Mass measurement of SHE with MR-TOF (Wada-san’s group).

GARIS-II Experimental plans : New SHE search, mass measurement, SHE chemistry, SHE spectroscopy

2015/11/09 27

ERs

New SHE search

Reactive gasor He+KCl aerosol

ERs

Recoil transferchamber

SHE chemistry SHE spectroscopy

Mass measurement

TOF detector

Si-Gedetector BOX

Projectile

Beam envelope

Differentialpumping

Target

Beam dump

Gas inletFocal plane

0 1 [m]

D2

D1

Q2Q3

Q1

MRTOFMANON

JCNP2015@OSAKA

May 29 D. Kaji-san

May 29 M. Wada-san

2015/11/09 JCNP2015@OSAKA 28

Thank you very much for your kind attention.

248Cm+HI Pb/Bi+HI

GARIS

GARIS-II

0 1 2 3 4 5100

101

102

v/v0

Tran

smis

sion

[%]

High performance of GARIS-IIHigh Transmission under Low BG level

2015/11/09 29

E [MeV]

Coun

ts

5 6 7 8 9 100

20

40

0 5 10 1510 0

10 1

10 2

10 3

10 4

10 5

GARIS-II (dose=2.4x1014)

245 F

m

211m

Po211 P

o

211 A

t

210 A

t

210 P

o

211 B

i

211 B

i

245 E

s

241 C

f

GARIS (dose=6.4x1014)

Trans = 63%

245 F

m

Succeeded in the observation of Fm isotope produced by 208Pb(40Ar,3n)245Fm.Observed a-peak due to 245Fm in singles! BG level was about 5 times lower than GARIS. Trans was 1.5 times higher than GARIS.

23N

a26

Mg

27Al 48

Ca

JCNP2015@OSAKA

2015/11/09 JCNP2015@OSAKA 30

2015/11/09 JCNP2015@OSAKA 31

Aritomo & Hagino