Synthesis, separation and determination of superheavy

elements

Supervisor: Лубош Крупа

Participants: Иржи Беран, Иван Хупка, Mартин Кaплaн, Штэфaн Нaкoв, Павэл Ныкл

• Reaction Mechanism

• Motivation

• Experimental Devices

• Medipix detector

• Results (graphs, charts)

• Conclusion

Motivation

• Synthesis of superheavy elements (with Z = 112 and 114) using 40Ar and 48Ca ion beam (112 – Hg analo-gue, 114 – Rn analogue?)

• Detection of evaporation residua in reactions 40Ar + natSm and 40Ar + 166Er and 48Ca + 242Pu by MASHA (Mass analyzer of superheavy atoms) and their alpha decays and spontaneous fission detection at the same time

Reaction mechanism

ER n

n n

Quasi-fission

CN fission

touching point

capture

Compound nucleus n

Quasi-elastic& Deep-inelastic

1

D1 Q1 Q2D2

Q3S1

D3aD3b

S2

23 4

Пучок ионов

• Mass • Analyser of • SuperHeavy • Atoms

1 – Target block with hot catcher; 2 – Ion source; 3 – Mass separator; 4 – DAQ in the focal plane.

General ion-optical parameters: Range of energy variation, keV 15-40 Range of Br variation, Tm 0.08-0.5 Mass acceptance, % +/-2.8 Angular acceptance, mrad +/-14 Diameter the ion source exit hole, mm 5.0 Horizontal magnification at F1/F2 0.39/0.68 Mass dispersion at F1/F2, mm/% 1.5/39.0 Linear mass resolution at F1 75 Mass resolution at F2 1300

Focal plane silicon multi strip detector

Configuration – well type

Number of the focal strips – 192 (step – 1.25 mm)

Number of the back side strips – 160 (step – 5 mm)

Medipix

• Planar (300, 700, 1000 m thick) silicon pixel detector (also GaAs, CdTe, or n converter)

• Bump-bonded to Medipix readout chip containing amplifier, discriminator and counter for each pixel.

5600 5800 6000 6200 6400

0

10

20

30

40

50

60

70

80

Counts

E [keV]

E (180

Hg) = 6111 keV

E (176

Pt) = 5746 keV

176Pt (E = 5753 keV) 180

Hg (E = 6120 keV)

40Ar (beam) +

144Sm (target) 184-x

Hg + xn

40 60 80 100 120 140 160 180 200

4,97

5,37

5,76

6,16

6,56

6,95

181Hg (3,6 s)

182Hg (10,83 s)

183Hg (9,4 s)

184Hg (30,9 s)

185Hg (49,1 s)

Strip

Energ

y [M

ev]

3,000

121,9

243,8

365,6

487,5

609,4

731,3

853,1

975,0

Counts40

Ar (beam) + nat

Sm (target)

180Hg (2,8 s)

5000 5500 6000 6500 7000

0

10

20

30

40

50

205At (E = 5902 keV)

40Ar (beam) +

166Er (target)

Counts

E [keV]

E (205

Rn) = 6261 keV

201Po (E = 5683 keV) 205

Rn (E = 6262 keV)

E205

At) = 5908 keV

(23 %)

206-xRn + xn

40 60 80 100 120 140 160 180 200

5,06

5,26

5,47

5,67

5,87

6,07

6,27

6,47

6,67

6,88

7,08

206Rn (5,67 m)

200Rn (1 s)

202Rn (10 s)

205Rn (2,8 m)

204Rn (1,24 m)

203Rn (45 s)

Strip

Energ

y [M

ev]

3,000

125,0

250,0

375,0

500,0

625,0

750,0

875,0

1000

Counts40

Ar (beam) + nat

Er (target)

201Rn (7 s)

5000 5500 6000 6500 7000 7500 8000

0

100

200

300

400

500

600

700

E (211

Bi) = 6262 keV

E (211

Bi) = 6605 keV

48Ca (beam) +

242Pu (target)

219Rn (E = 6539, 6819 keV)

215Po (E = 7386 keV)

E (215

Po) = 7359 keV

E (219

Rn) = 6407 keV

E (219

Rn) = 6539 keV Counts

E [keV]

E (219

Rn) = 6791 keV

215Po (E = 7386 keV)

211Bi (E = 6262, 6623 keV)

20 40 60 80 100 120 140

5,00

6,01

7,03

8,04

9,06

218Rn (35 ms)

219Rn (3,96 s)

Strip

Energ

y [M

eV

]

3,000

115,0

230,0

345,0

460,0

575,0

690,0

805,0

920,0

Counts48

Ca (beam) + 242

Pu (target)

212Rn (22,9 m)

Nuclide Half-life

212Rn 23,9 min

213Rn 25,0 ms 214Rn 0,27 μs 215Rn 2,3 μs 216Rn 45 μs

217Rn 0,54 ms 218Rn 35 ms 219Rn 3,96 s

Conclusion for the radio-isotopes • The ion-optical system adjustment of spectrometer “MASHA” and fine-tuning of ECR

ion source were carried out using the calibration of noble gases.

Ion source + Hot catcher

• The spectra of a particles after decay of their parent nuclei in the focal plane were measured by using silicon well-type detector. The relative yields of the radon isotopes at tree beam energies were determined. The obtained results indicate that these achieved the parameters of the mass-spectrometer “MASHA”, are close to similar designated values.

20 40 60 80 100 120 140

5,00

6,01

7,03

8,04

9,06

219Rn (35 ms)

219Rn (3,96 s)

Strip

En

erg

y [M

eV

]

3,000

115,0

230,0

345,0

460,0

575,0

690,0

805,0

920,0

Counts48

Ca (beam) + 242

Pu (target)

212Rn (22,9 m)

Thank you for your attention!