Preparation of gas-chemistry of Dubnium at IMP

Z. Qin, J.S. Guo, X.L. Wu, H.J.Ding, W.X.Huang, Z.G. Gan,

Institute of Modern Physics, Chinese Academy of Sciences,

content

1. Study of Transactinides by rotating wheel.

2. Preparation of Gas-chemistry for SHE.

10,40; 10,10...

sf; 20% sf; 22%

9,47

sf; (0.3%) 8,79 sf, ? sf;20%

8,37; 8,43 8,86; 8,80

Lr

103

104

Hs Hs 263 ?

?

Bh 262

108

Bh 261

10,38

Sg 262

6,9 ms

Bh11,8 ms?

Sg 261

105

102 ms8 ms

9,70

Rf

Bh 260 ?

Rf 256

6,2 ms

Rf 260

13 ms

Db 259

0,51 s

21 ms

111 ms

107

Sg

106

Db

Sg 258

2,9 ms

4,3 s

sf sf 8,77; 8,87

9,07 9,30; 9,01 8,93 9,04; 9,12

Rf 257 Rf 258 Rf 259

3 s

Db 257 Db 258

4 s

Db 261Db 260

1,5 s 1,8 s

Sg 259 Sg 260

0,48 s 3,6 ms

8,77; 8,87; sf7%

9,10; 9,18; (26%)

9,04; 9,12; /sf?

8,93; sf

9,62...; sf? 9,77; 9,72; sf

9,02; 8,97

2,7 s

10,51-10,57

9,56; 9,52; 9,47

0,45 ms

Hs 264

10.43; sf (50%)

78 s8,30; sf<11%

Rf 261

1,5 s

sf

9,07; 8,97sf (6%)

9,17 sf (13%)

0,76 s

8,2-8,9; (11%); sf1.4%; 117...

9,04; 9,12

Lr 255

21,5 s

9,04; 9,12

Lr 256

25,9 s

9,04; 9,12

Lr 257

0,65 s

9,04; 9,12

Lr 258

3,9 s 8,595; 8,621; 8,565; 8,654 9,04; 9,12

8,43; 8,52; 8,39... 8,77; 8,87

Lr 259

6,3 s 8,445...sf (23%)

10,18; sf<1,4% 9,18; 9,23

9,29 8,83

0,3 s

9,25

sf? sf;3% sf;?

8,03

Lr 261

39 m

~15 min

15,2 s

Bh 266Bh 264

Sg 265

~1 s ?

Rf 262

47 ms? 2,1 s

49 ms

Hs 269Hs 266

2,3 ms870s 1,6 ms 14 s

Hs 265 Hs 267

Sg 263

0.97 s

Bh 267

10,37

Rf 263 ?8,53 sf

Db 263Db 262

34 s 27 s

Sg 266

21 s0,9 s9,06; 9,25; sf

8,72; 8,59; sf82%

8,45; 8,53; 8,67; /sf(33%)

10,51-10,57

9,88; 9,83; 9,75

78 s8,30; sf<11%

4.2 s8,50; sf(40%)

Rf 261

7,4 s8,69-8,94; sf35%

8,36; sf (57%); (3+4

-1%)

9,04; 9,12

Lr 260

3 m

8,77; 8,87

sf? 9,04; 9,12

Lr 262

3,6 h

9,48; 9,62; sf (8%)

?

241Am( 22Ne , 4n) 259Db

?

Partial chart of nuclide

243Am( 26Mg , 4n) 265Bh

Energy constant: K ~ 70 (Ek~6-7MeV/A)

Intensity: ~ 3×1013 pps (C-Ne)

~ 5×1012 pps (Mg-Ar)

SFC: Sector Focusing Cyclotron, HIRFL

22Ne 241Am Fusion 263Db* 259Db

Hot fusion reaction

0.8 µA118 MeV 22Ne5+

Improved Rotating Wheel system

Transportationtime≈ 0.3 s

efficiency ≈ 50%He-NaCl-jet

241Am(910g/cm2)+ Al(1.7mg/cm2)

NaCl

259Db

Recoilchamber

A-1

A-2B

-1C

-1

A-3 B-2

D-1

B-3

D-3

C-2D-2

C-3

259 D

b

-spectrum of the reaction 22Ne +241Am

255 L

r

Decay-curve of 258,259Db and their daughter 254,255Lr

258DbE = 9.08, 9.17, 9.30 MeVT1/2 = 4.3±1.1s

254LrE= 8.46 MeVT1/2= 13.4±4.2s, 258Db T1/2= 4.3±1.4s

241Am(22Ne,4~5n)258,259Db

258Db4.4 s

4n5n

9.179.089.01

9.47

8.468.41

8.378.41

259Db0.5 s

254Lr13 s

255Lr21 s

Z.G. Gan, Z.Qin, H.M. Fan, et al., Eur. Phys. J., A10(2001)21

Rotating Multi-detector Arrays( ROMA)

-spectrum of the reaction 26Mg +243Am at energy of 168 MeV

ParenParentt

11 / keV / keVtt11 / /

msmsDaughtDaught

erer2 2 / /

keVkeVtt22 / /

ms ms

Grand-Grand-daughtdaught

erer3 3 / keV/ keV

tt33 / /

msms

265265BhBh 92689268 17361736 261261DbDb 90069006 48604860265265BhBh 93009300 10151015 261261DbDb 89248924 224224 257257LrLr 89058905 46394639265265BhBh 92199219 574574 261261DbDb 89218921 18981898 257257LrLr 88878887 14051405265265BhBh 92749274 193193 261261DbDb 89188918 58345834265265BhBh 92229222 11401140 261261DbDb 89428942 436436265265BhBh 91799179 19331933 261261DbDb 89028902 15231523265265BhBh 92459245 25472547 261261DbDb 88698869 16081608265265BhBh 91999199 13341334 261261DbDb 89278927 34803480264264BhBh 94409440 555555 260260DbDb 89888988 26862686264264BhBh 95019501 27702770 260260DbDb 90859085 13781378264264BhBh 95249524 12031203 260260DbDb 90039003 259259264264BhBh 94819481 23212321 260260DbDb 90989098 975975

- correlation events observed from 243Am(26Mg,4~5n)264,265Bh

243Am(26Mg,4~5n)264,265Bh

Z.G. Gan, J.S.Guo, X.L.Wu, Z.Qin, et al., Eur. Phys. J., A20(2004)385

264Bh1 s

4n5n

9.489.62 9.24

9.049.079.12

8.93

265Bh0.9 s

260Db1.5 s

261Db1.8 s

257Lr0.65 s

8.868.80

Q = 9.38 MeV

RMF calculation Q = 9.41 MeV

22Ne+249Bk 271Bh*

Berkeley, PRL, 85 (2000)2697

Beam: 300 particle nAEnergy: 117, 123 MeVTime: 62hDose: 4×1017

One Events of 266Bh: E=9.29 MeVlife-time:0.87s

Preliminary!!

278113278113

274Rg274Rg

270Mt270Mt

266Bh266Bh

CNCN

11.68 MeV (PSD)344 μs30.49 mm

11.15 MeV6.149+5.003 (PSD+SSD)9.260 ms30.40 mm

10.03 MeV 1.136+8.894(PSD+SSD)7.163 ms29.79 mm

9.08 MeV (PSD)2.469 s30.91 mm

36.75 MeVTOF 44.61 ns30.33 mm

1st chain

July 23, 2004 18:55 (JST)Morita et al.:JPSJ 73, 2593 (2004).

α

α

α

α

262Db262Db

204.05 MeV(PSD)40.9 s30.25 mm

278113278113

274Rg274Rg

270Mt270Mt

266Bh266Bh

CNCN

11.52 MeV (PSD)4.93 ms30.16 mm

0.88+10.43=11.31 MeV(PSD+SSD)34.3 ms29.61 mm

2.32 MeV (escape)1.63 s29.45 mm

9.77 MeV (PSD)1.31 s29.65 mm

36.47 MeVTOF 45.69 ns30.08 mm

2nd chain

April 2, 2005 2:18 (JST)

Decay chains of 278113

α

α

α

α

262Db262Db

192.32 MeV(PSD)0.787 s30.47 mm

SFSF σ = 39+53-25 fb

209Bi + 70Zn → 278113 + n

115 120 125 130 135 140 145 150 15510-12

10-11

1x10-10

1x10-9

1x10-8

1x10-7

1x10-6

Bh264 Bh265 Bh26626Mg + 243Am

Cro

ss s

ecti

on

(m

b)

Beam Energy (MeV)

HIVAP calculation

Beam energy: 162 MeV Beam energy: 162 MeV 2626MgMg8+8+

Beam intensity: 2 eA

Target: 1.2 mg/cm2 243Am

Transport efficiency: 50%

Detector efficiency: 30%

Stepping time:

Mother Mode:4s, Daughter Mode:60s

Irradiation time: 200h

Experiment condition

8.0 8.5 9.0 9.5 10.00

1

2

3

4

5

6

7

8

9

10

8.4

5 M

eV

262 D

b

9.0

7 M

eV

266 B

h

8.7

8 M

eV

212 P

o

Co

un

ts/1

0 k

eV

Energy (MeV)

-spectrum of the reaction 26Mg +243Am at energy of 162 MeV

- correlation events observed from 243Am(26Mg,3n)266Bh

Event No.

E1/MeV t1/s E2/MeV t2/s E1/MeV t3/s

1 8.989 1.13 8.459 33.62

2 9.128 0.88 8.676 33.84

3 9.071 0.79 8.604 34.14

4 8.959 0.51 8.542 29.23 8.641 5.07

- correlation energy window: 8.5-10 MeVDaughter life-time window: 20-60s

243Am(26Mg,3n)266Bh

266Bh~0.9 s

262Db34 s

258Lr4 s

9.04

8.458.538.67

8.608.628.578.65

LBL RIKEN 1st RIKEN 2nd This work

E(MeV) 9.29 9.08 9.77 9.04

Lifetime (s) 0.87 2.469 1.31 0.9

Decay properties of 266Bh

Comparison of Q value from the experiment with Macro-micro Model

144 146 148 150 152 154 156 158 160 162 164 166 168 1706

7

8

9

10

11

266Bh

259Db and 265Bh

I. Muntian, S. Hofmann, Z. Patyk and A. Sobiczewski Acta Physica Polonica B34(2003)2073

LrNo

Rf

DbSg

Bh

Q

(MeV

)

Neutron Number

DsDs

H

Li

Na

K

Rb

Cs

Fr Ra Ac

Ba

Sr

Ca

Mg

Be

Sc

Y

La

Ti

Zr

Hf

V

Nb

Ta

Cr

Mo

W

Mn

Tc

Re

Fe

Ru

Os

Co Ni Cu Zn Ga Ge As

Rh Pd Ag Cd In Sn Sb

Ir Pt Au Hg Tl Pb Bi

Rf Db Sg

B C N O F

Al Si P S Cl

Se Br

Te I

Po At87 88 89 104 105 106

55 56 57 72 73 74 75 76 77

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

78 79 80 81 82 83 84 85

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

11 12 13 14 15 16 17

3 4

1

5 6 7 8 9

PeriodicPeriodic Table of Table of thethe ElementsElements1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

58

90

59 60 61 62

91 92 93 94

63

95 96 97 98 99 100 101

64 65 66 67 68 69

102 103

70 71

LanthanidesLanthanides

ActinidesActinides

Bh107

Hs

Mt

108

109 110

Rg Rg 111

112

114

- -116

- -

He

Ne

Ar

Kr

Xe

Rn

54

86

36

18

10

2

18

113113

114114

115115

116116

118118

Production of Dubnium: 243Am( 20Ne, 4~5n)258, 259Db

258Db: T1/2 = 4.4s, E = 9.17, 9.08, 9.01 MeV

Carrier gas: He/KBr

Reaction gas: HBr

Gas-chemistry: OLGA-III

Detection: Rotating wheel system

On-line gas chemistry Apparatus OLGA-III

Summary

1. Two new isotopes of 259Db and 265Bh were synthesized

2. The known isotope of 266Bh was studied, and E close to the RIKEN first chain.

3. Db gas chemistry is under going.

Thank you for attention