Experimental data analysis at the MASHA setup. Prepared by: Abeer M. Attia Supervisor: Lubos Krupa LOGO. Aleksey Novoselov

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1 Experimental data analysis at the MASHA setup Flerov Laboratory of Nuclear Reactions JINR, Dubna, Russia Prepared by: Abeer M. Attia Supervisor: Lubos Krupa LOGO Aleksey Novoselov Flerov Laboratory of Nuclear Reactions, JINR, Dubna

2 Contents Synthesis of new elements MASHA setup Data analysis Conclusion

3 Introduction Where is the end of the periodical table of elements? In May 1957 the 2nd session of the JINR Scientific Council reached a decision to found the Laboratory of Nuclear Reactions (LNR) with a special-purpose cyclotron for heavy ion research. 105 Db Dubnium (1997), 114 Fl Flerovium (2012). Six new super heavy elements with Z= and more than 50 new isotopes of SHE with Z= have been synthesized. MASHA is the mass-spectrometer which can measure masses of the synthesized isotopes simultaneously with registration of their α-decay or spontaneous fission.

4 Stability curve Nuclear Stability is a concept that helps to identify the stability of an isotope. The two main factors that determine nuclear stability are the neutron/proton ratio and the total number of nucleons in the nucleus.

5 The mass- spectrometer is connected to the U- 400M cyclotron of the FLNR, JINR, Dubna Mass-spectrometer MASHA at the beam line of the cyclotron U-400M Company Logo

6 Experimental set up (Mass Spectrometer MASHA) Mass Separator of Heavy Atoms Пучок ионов 1 D1 1 Target box with hot catcher; 2 Ion source; 3 Mass separator; 4 DAQ in the focal plane. 2 Q1 Q2 D2 3 4 S2 Q3 S1 D3b D3a General ion-optical parameters: Range of energy variation, kv Range of Br variation, Tm 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 The proposed setup is a combination of the so-called ISOL method of synthesis and separation of radioactive nuclei with the classical method of mass analysis, allowing mass identification of the synthesized nuclides in the wide mass range (A = u).

7 MASHA Setup

Hot catcher scheme ECR ion source Hot catcher Target Beam line Recoil transport Material of the catcher flexible graphite, Density of 1g/cm 3, a thickness

8 Hot catcher scheme ECR ion source Hot catcher Target Beam line Recoil transport Material of the catcher flexible graphite, Density of 1g/cm 3, a thickness of 0.6 mm and shaped as a 30 mm diameter disk. Operating temperature of hot catcher о С. Delivery time of nuclides to the ECR ion source < 1.8 s.

9 Hot Catcher Heating up to 1800 o C

10 Ion source + Hot catcher (top view) Nuclear reaction products escape from the target, pass through the separating foil, and are stopped in the graphite absorber. In the form of atoms, the products diffuse from the graphite absorber to the vacuum volume of the hot catcher and, moving over the pipeline, reach the ECR source, where are ionized to charge state Q = +1 and accelerated with the aid of the three electrode system.

11 Equipment description

25 mm) Number of the back side strips: 160 (step 5 mm) E resolution for α particles from 226Ra source ~30 kev

12 Detectors Focal plane silicon multi strip detector TIMEPIX detector Configuration:. well type Number of the focal strips: 192 (step 1.25 mm) Number of the back side strips: 160 (step 5 mm) E resolution for α particles from 226Ra source ~30 kev Total efficiency: more than 90%. An array of 256x256 square pixels of pitch size 55mm for full sensitive area 14x14 mm 2. Silicon sensor of 300 mm width. E resolution for α particles from 220Rn ~100keV

13 DAQ PXI chassis with XIA digitizers, NI controller and crate with multiplexors (left photo). Examples of signals from one strip (right pictures).

14 Data analysis Reactions: 40 Ar+ nat Sm nat-xn Hg+xn mercury isotopes. 40 Ar+ 166 Er 206 xn Rn+xn radon isotopes. Beam: 40 Ar, E=284 MeV Average intensity 1.2*10 12 pps. Targets: nat Sm Sm 2 O 3, d=0.63 mg/cm 2 (for Sm) on Ti foil 3.14 µm 166 Er Er 2 O 3, d=0.67 mg/cm 2 (for Er) on Ti foil 3.14 µm Method of the manufacturing molecular electrodeposition.

15 40 Ar+ 166 Er reaction 1-Dimensional spectra for Radon isotopes

16 40 Ar+ 166 Er reaction 1-Dimensional spectra for Radon isotopes

17 40 Ar+ 166 Er reaction 1-Dimensional spectra for Radon isotopes

18 40 Ar+ 166 Er reaction 2-dimensional plot of alpha particle energies

19 40 Ar+ nat Sm reaction 1-Dimensional spectra of 180 Hg, 181 Hg, 182 Hg & 183 Hg

20 40 Ar+ nat Sm reaction 1-Dimensional spectra of 180 Hg, 181 Hg, 182 Hg & 183 Hg

21 40 Ar+ nat Sm reaction 1-Dimensional spectra of 180 Hg, 181 Hg, 182 Hg & 183 Hg

22 40 Ar+ nat Sm reaction 2-dimensional plot of alpha particle energies

23 Conclusion The isotopes of Hg and Rn were produced in the fusionevaporation residue reactions 40 Ar + nat Sm and 40 Ar Er. Their chemical properties (adsorption energy on the surface) are close to those of 112 and 114. The spectra of alpha particles after decay of isotopes in the focal plane were measured by silicon well-type detector. Useful information that can be obtained from experiments carried in mass spectrometer Masha are: 1. Yields of isotopes (if interested in future production of that isotope). 1. Cross Section. 2. Identification of isotopes.

24 Thank you! LOGO

SYNTHESIS OF SUPERHEAVY ELEMENTS USING THE MASS SPECTROMETER MASHA

SYNTHESIS OF SUPERHEAVY ELEMENTS USING THE MASS SPECTROMETER MASHA Students Timofei Tikhomirov - RB Kevin Li - RSA Alesya Lebedevich - RB Maurice Mashau - RSA Supervisor Krupa Lubosh Flerov Laboratiory