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The Study of Multi-nucleon Transfer Reaction of 136Xe + 198Pt Above the Coulomb Barrier
쿨롱 장벽 위에서 136Xe + 198Pt의 다중 핵 전달 반응의 연구

DC Field Value Language
dc.contributor.advisor최선호-
dc.contributor.authorKim Yung Hee-
dc.date.accessioned2017-07-19T06:08:58Z-
dc.date.available2017-07-19T06:08:58Z-
dc.date.issued2015-08-
dc.identifier.other000000066978-
dc.identifier.urihttp://dcollection.snu.ac.kr:80/jsp/common/DcLoOrgPer.jsp?sItemId=000000066978-
dc.description학위논문(박사)--서울대학교 대학원 :자연과학대학 물리·천문학부,2015. 8. 최선호.-
dc.description.abstractThe neutron-rich isotopes far from stability, around the mass number A~200 forms the last waiting point of the r-process towards the synthesis of uranium.
But, the difficulty of producing such nuclei with conventional methods, limited the current knowledge of such nuclides (e.g. half-life, mass, etc.) to the region close to the valley of stability.
The multi-nucleon transfer (MNT) reaction recently attracts much attentions as the candidate to produce nuclides in this neutron-rich region.
The MNT reactions with the combination of heavy neutron-rich projectile, such as 136Xe with target nucleus (e.g. 208Pb or 198Pt) is anticipated to have large cross sections for the producing neutron-rich target-like fragments (TLF's) [9, 14, 26]. However, the MNT reactions in such heavy systems have not been studied well.
We performed an experiment using 136Xe+198Pt system with the beam energy 8MeV/u ( 55% above the Coulomb barrier).
The large acceptance VAMOS++ spectrometer [83] and the EXOGAM Ge-detector array [96] at GANIL were used.
First, to investigate the feasibility of the MNT reaction for producing neutron rich exotic nuclei.
Second, to study reaction mechanism between heavy neutron-rich beam, and target with similar N/Z ratio.
The event-by-event particle identification of projectile-like fragments (PLF's)were successfully carried out [119].
The cross sections of PLF, and TLF (calculated from information of PLF) will be presented, comparison with the GRAZING code [20] and TDHF [35] calculation.
The evolution of reaction concerning nucleon transfer by moment analysis of correlation between mass and atomic number distribution(e.g. mean, width, and correlation of atomic number/mass distribution) will be discussed.
This experimental result confirmed the MNT reaction between 136Xe+198Pt above the Coulomb barrier can produce neutron rich nuclides with N = 126 magic
number for the first time.
And observed neutron rich nuclides are produced from reaction with low excitation energy before N/Z-equilibrium is reached.
This result will offer new possiblity to explore astronomically and nuclear physically
important new territory of nuclear chart.
And encourage new facilities that use MNT reactions for producing new isotope beam.
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dc.description.tableofcontents1 Introduction 1
1.1 Motivation of the experiment . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Production of N 126 nuclides . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Previous studies of reaction mechanism:Reaction mechanism of MNT
reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.4 Perspective of this experiment . . . . . . . . . . . . . . . . . . . . . . 24
2 Theory of Multi-nucleon Transfer Reaction 25
2.1 Characteristics of Multi-nucleon Transfer Rection . . . . . . . . . . . 25
2.1.1 Partial statistical equilibrium (Q-value dependence) . . . . . 25
2.1.2 N/Z equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.2 Reaction kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.3 Quasi-elastic and Deep Inelastic Reaction . . . . . . . . . . . . . . . 40
2.3.1 Deep inelastic collision (D.I.C.) . . . . . . . . . . . . . . . . . 41
2.4 Uni ed models MNT reactions . . . . . . . . . . . . . . . . . . . . . 45
2.4.1 Grazing model . . . . . . . . . . . . . . . . . . . . . . . . . . 45
2.4.2 Time dependent Hartree Fork (TDHF) theory . . . . . . . . . 48
3 Experimental Setup 56
3.1 Accelerator Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.2 Beam target combination consideration . . . . . . . . . . . . . . . . 58
3.2.1 Beam and target nuclei . . . . . . . . . . . . . . . . . . . . . 58
3.2.2 Beam energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
3.2.3 Spectrometer angle . . . . . . . . . . . . . . . . . . . . . . . . 60
3.2.4 Target thickness . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.2.5 B of spectrometer . . . . . . . . . . . . . . . . . . . . . . . 61
3.2.6 Beam time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
3.3 VAMOS++ sepctrometer . . . . . . . . . . . . . . . . . . . . . . . . 65
3.3.1 Electro-Magmentic elements of VAMOS++ . . . . . . . . . . 66
3.3.2 Detectors of VAMOS++ . . . . . . . . . . . . . . . . . . . . . 66
3.3.3 Event Reconstruction . . . . . . . . . . . . . . . . . . . . . . 79
3.4 EXOGAM Ge-clover Array . . . . . . . . . . . . . . . . . . . . . . . 81
3.4.1 Electric circuit and trigger system . . . . . . . . . . . . . . . 86
3.5 Tandem experimental result . . . . . . . . . . . . . . . . . . . . . . . 95
4 Presorted Experimental Data: Calibration, PID, and Corrections 100
4.1 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.1.1 Multi-wire parallel plate avalanche counter calibration . . . . 100
4.1.2 Drift chamber calibration . . . . . . . . . . . . . . . . . . . . 103
4.1.3 Si, IC energy calibration . . . . . . . . . . . . . . . . . . . . . 105
4.1.4 Ge detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
4.1.5 Timing calibration . . . . . . . . . . . . . . . . . . . . . . . . 110
4.2 Particle Identi cation . . . . . . . . . . . . . . . . . . . . . . . . . . 118
4.2.1 Total Energy Calibration and Charge state identi cation . . 118
4.2.2 Mass number identi cation . . . . . . . . . . . . . . . . . . . 127
4.2.3 Atomic number identi cation . . . . . . . . . . . . . . . . . . 130
4.3 Spectrometer Detection E ciency . . . . . . . . . . . . . . . . . . . 134
4.3.1 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
4.3.2 Beam position uncertainty . . . . . . . . . . . . . . . . . . . . 138
4.3.3 Detection e ciency correction using charge state . . . . . . . 144
4.3.4 Restoration of events out side of the acceptance . . . . . . . . 154
5 Analyzed Results and Discussion 165
5.1 Elastic Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
5.1.1 Selection of elastic scattering channel from 136Xe . . . . . . . 166
5.1.2 Conversion factor calculation . . . . . . . . . . . . . . . . . . 169
5.1.3 Optical potential tting . . . . . . . . . . . . . . . . . . . . . 170
5.1.4 Comparison with tandem experiment . . . . . . . . . . . . . . 172
5.2 Cross section of projectile-like fragments . . . . . . . . . . . . . . . . 172
5.3 Decomposition of Q.E. and D.I.C. . . . . . . . . . . . . . . . . . . . 177
5.3.1 Di erent factors of nucleon transfer dependency in Q.E. and
D.I.C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
5.4 Reaction kinematics of PLFs . . . . . . . . . . . . . . . . . . . . . . 183
5.4.1 Wilczynski plot . . . . . . . . . . . . . . . . . . . . . . . . . . 183
5.4.2 n,p-transfer dependence of Wilzynski plot . . . . . . . . . . . 186
5.5 pre-evaporation fragment and Excitation Energy Determination . . . 191
5.5.1 Iteration method . . . . . . . . . . . . . . . . . . . . . . . . . 196
5.5.2 Resolution of the E
total calculation . . . . . . . . . . . . . . . 203
5.5.3 Limit of the E
total calculation . . . . . . . . . . . . . . . . . . 203
5.5.4 Pre-evaporated fragment cross section . . . . . . . . . . . . . 205
5.5.5 Pre-evaporation fragment cross section E
total < 100MeV . . . 210
5.6 Evolution of Reaction as Function of E
total . . . . . . . . . . . . . . . 213
5.6.1 < M >, < Z > and < N > of the distribution . . . . . . . . 213
5.6.2 < M(E T
OT ;Z) > distance from N/Z equilibrium mass . . . . 218
5.6.3 Variance of proton, neutron distribution . . . . . . . . . . . . 222
5.6.4 Correlation of proton and neutron transfer . . . . . . . . . . 228
5.7 TLF cross section and feasibility of n-rich nuclides . . . . . . . . . . 229
5.7.1 TLF cross section after evaporation . . . . . . . . . . . . . . 230
5.7.2 Evolution of TLF as function of excitation energy . . . . . . 236
5.7.3 TLF PID con rmation . . . . . . . . . . . . . . . . . . . . . . 236
5.7.4 Feasibility of producing n-rich TLF . . . . . . . . . . . . . . . 242
5.7.5 The kinematics of the TLF . . . . . . . . . . . . . . . . . . . 244
6 Conclusions 250
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dc.format.extentxxxvii,267-
dc.language.isoeng-
dc.publisher서울대학교 대학원-
dc.subjectMulti-nucleon transfer reaction, reaction between heavy ions, reaction-
dc.subject.ddc523-
dc.titleThe Study of Multi-nucleon Transfer Reaction of 136Xe + 198Pt Above the Coulomb Barrier-
dc.title.alternative쿨롱 장벽 위에서 136Xe + 198Pt의 다중 핵 전달 반응의 연구-
dc.typeThesis-
dc.typeDissertation-
dc.contributor.AlternativeAuthor김융희-
dc.contributor.department자연과학대학 물리·천문학부-
dc.description.degreeDoctor-
dc.date.awarded2015-08-
dc.contributor.major실험 핵 물리학-
dc.identifier.holdings000000000023▲000000000025▲000000066978▲-
Appears in Collections:
College of Natural Sciences (자연과학대학)Dept. of Physics and Astronomy (물리·천문학부)Physics (물리학전공)Theses (Ph.D. / Sc.D._물리학전공)
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