The peculiarities of the production

and decay of superheavy nuclei

M.G.Itkis

Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia

The dynamics of the fusion-fission of superheavy nuclei

Experimental results. The peculiarities of the observables, the signatures of the Fusion-Fission/Quasi-Fission processes, multimodal fission phenomena

The recent results on synthesis of superheavy nuclei

The perspectives of the “hot” fusion reaction for the production of superheavy nuclei

Shape evolution in Fusion-Fission reactions

Elastic scattering Coulomb excitation Quasi-elastic scattering Deep-inelastic scattering Incomplete pulse transfer Fast-fission Quasi-fission Fusion → CN → Fission Fusion → CN → de-excitation (n,)→ ER

In dependence on impact parameter and projectile energy :

Kinematics coincidence method. Double arm time-of-flight spectrometer CORSET

Experimental results

The sharp change of the MED triangular shape for the reaction 48Ca+208Pb, where Fusion-Fission process dominates, to the Quasi-Fission shape of MED for the 286112-296116 nuclei.

The wide two-humped mass distribution with high peak of heavy fragment near double magic lead (MH208) for the Quasi-Fission process.

In spite of the dominating role of the Quasi-Fission process for these reactions we assume that in the symmetric region of the fragment masses (A/220) FF process coexists with QF.

The Fusion-Fission mass distribution is asymmetric in shape with mass of the light fragment ML132-134 amu ( see on the framings)

Mass-energy distributions of the fission fragments of 256102- 296116 nuclei produced in “hot” fusion reactions with 48Ca-projectiles

E* 33 MeV

Mass Asymmetry in Low Energy Fission of Superheavy nuclei

E*33-40 MeV

Hot fusion reaction48Ca + 248Cm 296116

Fusion-Fission DynamicsM.G.Itkis, Yu.Ts.Oganessian, V.I.Zagrebaev, Phys.Rev.C65,2002, 044602

To

tal k

ine

tic e

ne

rgy

(Me

V)

Mas

s a

sym

me

try

(A1-A

2)/

(A1+

A2)

Fragment mass number (u)Y

ield

,%

Cold fusion reaction

Neutron and -emission as probe FF/QF

Neutron multi-detectors “DEMON” with trigger of fission fragments “CORSET”

Two-dimensional matrixes TKE-Mass, Mass Yields, neutron multiplicities (pre, post and tot) for the reactions 48Ca+208Pb and 48Ca+238U

Total neutron multiplicities as function of atomic number of compound nuclei produced in the reaction with 26Mg, 48Ca and 58Fe-projectiles

Two-dimensional matrixes TKE-Mass, Mass Yields, neutron and -multiplicities for the reaction with 48Ca-projectiles on the targets 208Pb,238U, 244Pu,248Cm

Capture and Fusion-Fission Cross Sections

The perspectives of the “hot” fusion reaction for the production of superheavy nuclei

Shell effects manifestation

QF/

cap (

%)

Natural occurrence of Ca isotopes (in %):

40Ca – 96.9442Ca – 0.64743Ca – 0.13544Ca – 2.08646Ca – 0.004

48Ca – 0.187 beam tim e - 4000 h/y

beam intensity - 4 - 8 .10 /s

12

C onsum ption of m g/h 48 С а (68% ) - 0.5

Isotopes:

+U , P u , A m , C m[233 , 238 ] [242, 244] [245, 247], [249][243 ] C f Z = 112 - 118 48 C a

x 400

→ Ca5+

isotope productionhigh flux reactors

(Oak Ridge, Dimitrovgrad)

isotope enrichment 98-99%S-2 separator

(Sarov)

technology of the target preparation – 0.3 mg/cm2

Separation of super heavy nuclei and detection of their radioactive decays

now: DGFRS

D u bn a G as F illed R ec o il S e p a ra to r

v (A=48) = 0.11 cq = 16.5+

v (A=288) = 0.017 cq = 6.2+

- -SF

0 .1

104n

A = 2 8 8

5n[2 8 7 ]

3n[2 8 9 ]

5

0 .5

B C

Cro

ss s

ectio

ns (

pb)

1

P u -ta rg et 2 4 4

30E xcita tion energ y (M eV )4035

35

45 50 55

P u -ta rg et 2 4 2

B C

4n[2 8 6 ]

3n[2 8 7 ]

10

5

0 .5

0 .130

E xcita tion energ y (M eV )

Cro

ss s

ectio

ns (

pb)

4 0 45 50 55

1

U -ta rge t 2 3 8

B C

4n[2 8 2 ]

3n[2 8 3 ]

- -SF-S F -SFand SF

- -SF

-SFand SFSF

Isotope charge (Z) and mass (A) identificationsobtained by the measurements of neutron evaporation cross sections vs. excitation

energy of compound nucleus

2n[288]

-SF

Decay Chains Observed in 243Am + 48Ca Reaction

10.51 MeV

10.4 MeV

E = 248 MeV L

a) b)

E = 253 MeV L

11.0 MeV 9.1 MeV

9.72 MeV

9.65 MeV

80.3 ms

0.376 s

3.146 s

24.103 s

1.055 s

1 8 . 6 m m

1 8 . 5 m m 2 3 . 3 m m 1 8 . 8 m m

2 1 . 3 m m

1 8 . 4 m m

1 8 . 8 m m

1 8 . 5 m m

115

R R R

113

111

Mt

Bh

288

284

280

276

272

9. MeV 02. s2 964. m m 2 3 6

9.7 MeV 6. s10 599. m m 2 3 7

10.38 MeV 18. ms6

. s1 196

. s0 249

. m m 2 3 7

115

113

111

Mt

Bh

288

284

280

276

272

. s15 388. m m 1 8 1

9.7 MeV 6

9.7 MeV 4

. s1 723

. s1 834

. m m 1 8 1

. m m 1 9 2

10 00 . MeV

10. MeV 50 ms280

. s0 517

. m m 1 8 5

. m m 1 8 7

115

113

111

Mt

Bh

288

284

280

276

272

SF140 MeV 16 98. h1 7 8. m m

Db268

5

4

3

2

1

5

4

3

2

1

5

4

3

2

1

T h e b e a m w a s s w i t c h e d o f f

9.23+_0.61 MeV

0.376 s

28.70 h 1 8 . 2 m m

SF

Db268

205 MeV

9. +_0.61 MeV 48

9. +_0.61 MeV 80

SF

2 . h3 54 2 3 . 2 m m

Db268

20 MeV0

10. MeV04

8.97 MeV

1 7 . 9 m m

105.96 min

1

12.2 MeV 1 8 . 0 m m

R

10.33 MeV 14.0 ms

7 . 7 m m 1

10.59 MeV

10. MeV 12

46. ms6

0.147 s

. 6 m m 1 7

. 7 m m 1 7

115

113

111

Mt

287

279

275

10.37 MeV . s0 245

SF

Db267

206 MeV

Bh271

283

1 0 4

11 0

11 4

1 2 0 -d e c a y

N e u tro n n u m b e r

prot

on n

umbe

r

1 s

1 m s

1 s

o d d -o d d

1 5 0 1 7 0 1 8 0 1 9 0

1 0 s9

1 0 s3

1 0 s6

_

-d e c a y

T =1.5 s1/2

Bh

Mt

111

Db

209 64Bi+ Ni

115

243 48Am+ Ca

113

111

Mt

Bh

Rf

T 1 d1/2

Db

odd-odd

1 1 4

2 8 6

1 1 6

2 9 0 1 1 . 8 0 +_ 0 . 5 3 M e V

0 . 8 5 m s 1 3 . 6 6 M e V

1 7 .5 m m

1 1 81 1 8

2 9 4 2 9 7

M a r c h 1 9 , 2 0 0 5

0 7 : 4 3

S F

1 1 2

2 8 2 1 0 . 1 6 M e V

0 . 1 5 s

1 6 . 8 m m

2 0 2 ( 1 5 1 + 5 1 ) M e V

2 . 7 m s

1 6 . 9 m m

1 0 . 8 0 M e V

0 . 1 m s

1 7 . 0 m m

1

2

3

Synthesis of Element 118 in 249Cf + 48Ca Reaction

S F

M arch 19 , 2002 05:28

11 .6 5 M e V 2 .5 5 m s 9 .0 m m

1 3 .2 2 M e V 8 .9 m m

2 0 7 (1 8 8 + 1 9 ) M e V5 1 6 .6 m s9 .4 m m

1 0 .7 1 +- 0 .1 8 M e V4 2 m s1 5 .1+_ 7 .3 m m

11 82 9 7

11 82 9 4

11 62 9 0

11 42 8 6

1

2

2002

20052002 - 2004

3 n2 n

118294

118295

245Cm+48Ca

242Pu+48Ca

238U+48Ca 10.02 MeV

26.3 ms

0.68 s

116

114

112

291

287

283

1

2

SF(~90%)

SF(~30%)

10.74 MeV

970. MeV

7.87 s

0.28 s

110

108

279

275

3

49.5 MeV

8.53 MeV

0.3 s

2.80 min104267

5

6 9.30 MeV

1.84 h

SF

10.16 MeV

6.23 ms

0.55 s

116

112

290

282

1

2

1.0 ms

SF

SF(~60%)

10.5 MeV8114

286

106271

neutron number

111112113

114

117

115

118

116

160 162

164 166 168 170 172 174

176 178 180 182 184

152 158156154

Mt 266

Db 262 Db 263

Sg 266

Db 258Db 256 Db 260Db 257

Rf 260 Rf 261 Rf 262 Rf 263Rf 259Rf 256Rf 255 Rf 258

Bh 261 Bh 262

Rf 257

Db 261

Sg 260 Sg 261 Sg 263Sg 259

Bh 264BhHs

Ds

Sg 258

Lr 259

No 258

Lr 260

No 259

Lr 261 Lr 262

No 262No 260

Lr 258

No 257

Lr 255

No 254

Lr 254

No 253

Lr 257

No 256

Lr 256

No 255

Md 257

Fm 256

Md 258

Fm 257

Md 259 Md 260

Fm 258 Fm 259

Md 256

Fm 255

Md 253

Fm 252

Md 252

Fm 251

Md 255

Fm 254

Md 254

Fm 253

Es 255 Es 256Es 254Es 251Es 250 Es 253Es 252

Cf 255 Cf 256Cf 253Cf 250Cf 249 Cf 251 Cf 252 Cf 254

110/273110/271

111/272

CHART OF THE NUCLIDES

NoMdFmEsCf

pro

ton

n

um

ber

150

DbRfLrNoMdFmEsCf

Z = 114

108Hs 267Hs 265Hs 264

a

aa

aa

a

110/270

Hs 266

Sg 262

112/2859.1539 s

Z/A

T1/2

E (MeV)

110/269

Mt 268

EC

-

SF

112/277

110/267

MtHs 269 Hs 270

Sg 265Sg

aaa

aa

aa

aa

aa

a

aa

a aa

aaaa

108/275

110/279

106/271

112/284112/282

114/286114/28710.01

114/2889.95

116/290

115/288115/287

113/284113/283

111/280

109/276

107/272

111/279

109/257

116/29110.85 10.74

112/285

110/281

114/2899.82

9.169.54

9.30

8.53

10.00

10.4610.59

10.12

9.75

9.71

9.02

10.37

10.33

105/268

15 ms

32 ms 87 m s

6.3 m s

0.1 s

0.15 s

0.17 s

0.72 s

9.8 s

16 h

9.7 m s

0.48 s

0.1 s0.5 m s

3.6 s

0.18 s

2.4 m in

9.6 s

34 s

0.56 s 0.63 s 2.7 s0.16 s10.20

112/2834.0 s

a116/29210.6616 ms

107/217

116/29353 ms

1.8 ms118/29411.65

105/2671.2 h

10.53

9.70

104/268104/2672.3 h

48 238 249Ca + U.... Cf

208 50 70Pb + Ti.... ZnNumber of

observed decays

Z = 118 3 116 23

114 45 112 52

The formation of 294116 in the reactions with 48Ca and 50Ti-ions

Mass-energy distributions of the fission fragments

Capture cross sections for the reactions 50Ti+244Pu and 48Ca+246Cm

N=174 N=182 N=184 N=184

Reactions of the production of 116-122 elements with 58Fe and 64Ni-projectiles

1 50 1 60 1 70 1 80 1 901 40

1 5

2 0

1 0

-5

-1 0

11 6

11 6

11 8

11 2

11 2

11 4

11 4

11 0

11 0

1 0 8

1 0 8

- d ecay

fa s t ch em istry ava ilab le

D efo rm edS he ll

S ph erica lS he ll

A ge o f the E arth

s ta b len u c le i

1 50 1 60 1 70 1 80 1 901 40

1 5

2 0

1 0

5

0

-5

-1 0

11 6

11 6

11 8

11 2

11 2

11 4

11 4

11 0

11 0

1 0 8

1 0 8

N eu tro n n u m b er

- d ecay

fa s t ch em istry ava ilab le

D efo rm edS he ll

S ph erica lS he ll

Log

T (

seco

nds)

A ge o f the E arthT h e o ry a n d E x p e r im e n t

s ta b len u c le i

th e e x p e r im e n ta ll im it o f th e se a rc h fo r S H E in N a tu re

108 y

105 y

1 y

1 d

the search for SHE in Cosmic rays

H

1

Li

3

Be

4

Na

11

M g

12

K

19

Ca

20

Sc

21

104

Ti

22

V

23

Cr

24

M n

25

Fe

26

Co

27

Ni

28

Cu

29

Zn

30

1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

18

1

2

3

4

5

6

He

B

Al Si P S

ONC F

Cl Ar

Ne

7105 106 107

72 73 74 75 76 77 78 79 80 81 82 83 84 85 8655 56

87 88

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

31 32 33 34 35 36

Rf Db Sg Bh

Rb Sr Y Zr Nb M o Tc Ru Rh Pd Ag Cd In Sn Sb Tc I Xe

Cs Ba Hf Ta W Re O s Ir Pt Au Hg Ti Pb Bi Po At Rn

Fr Ra

G a G e As Se Br Kr

108 109 110 111 112 113 115114 116 117 118

Hs M t

Dar

ms-

tad

tiu

m

Ds Rg

117

Periodic Table of the Elem ents

Search in NatureSearch in Nature

Chemical properties (relativistic effect)Chemical properties (relativistic effect)

Astrophysics (search for SHE in cosmic rays)Astrophysics (search for SHE in cosmic rays)

Nucleosynthesis (test of the r-s process) Nucleosynthesis (test of the r-s process)

Atomic physics (structure of SH-atoms)Atomic physics (structure of SH-atoms)

Elements with Z ≥ 120

Flerov Laboratory of Nuclear Reactions of JINR

…in February

Thanks for your attention