Synthesis, separation andnewuc.jinr.ru/img_sections/file/Practice2015/Student presentations/E… ·...
Transcript of Synthesis, separation andnewuc.jinr.ru/img_sections/file/Practice2015/Student presentations/E… ·...
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!