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Study of 19C by One-Neutron Knockout Reaction with a Carbon Target
탄소 표적과 중성자 탈락 반응을 이용한 탄소-19 핵종에 대한 연구

DC Field Value Language
dc.contributor.advisor최선호-
dc.contributor.authorJongwon Hwang-
dc.date.accessioned2017-07-19T06:09:24Z-
dc.date.available2017-07-19T06:09:24Z-
dc.date.issued2015-08-
dc.identifier.other000000067486-
dc.identifier.urihttp://dcollection.snu.ac.kr:80/jsp/common/DcLoOrgPer.jsp?sItemId=000000067486-
dc.description학위논문(박사)--서울대학교 대학원 :자연과학대학 물리·천문학부,2015. 8. 최선호.-
dc.description.abstractThe level structure of a neutron-rich nucleus 19C, which is known as a one-neutron halo, was studied via one-neutron (1n) knockout reaction with a 20C beam and a carbon target at 280 MeV/nucleon. Three prominent resonances were observed at E rel = 0.036(1), 0.84(4), and 2.31(3) MeV in the invariant
mass spectrum constructed from momentum vectors of decay products of the knockout residue, a 18C isotope and a neutron. The resonances correspond
to the neutron-unbound states in 19C at excitation energies of E x = 0.62(9), 1.42(10), and 2.89(10) MeV. The spin-parities of the 0.62-MeV and 2.89-MeV states were determined to be 5/2+1 and 1/2-1, respectively, by comparing the data with eikonal model calculations employing shell-model spectroscopic factors in terms of the 1n knockout cross section and the parallel momentum distribution.

We have clarified that the 0.62-MeV state is unbound and assigned its spin-parity with the direct evidence. The 1.42-MeV state is consistent with the 5/2+2 state, which is located at 1.46 MeV by the proton inelastic scattering measurement. The state at 2.89 MeV in 19C with a negative parity was observed for the first time, and its spin-parity was clearly determined. In addition, the shell structure involving the neutron 1s 1/2 and 0d 5/2 orbitals is discussed.
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dc.description.tableofcontents1. Introduction 1
1.1 19C 5
1.2 One-neutron knockout reaction 6
2. Method 8
2.1 One-neutron knockout reaction 8
2.1.1 Introduction 8
2.1.2 General features 10
2.1.3 Eikonal reaction theory 12
2.2 Invariant mass method 15
2.3 Parallel momentum distribution 16
2.4 R-matrix formalism 19
2.4.1 Resonance cross section 20
2.4.2 Penetrability factor Pl and shift factor Sl 21
3. Experiment 24
3.1 BigRIPS separator 24
3.2 SAMURAI spectrometer 26
3.2.1 Dipole magnet 27
3.3 Detectors 29
3.3.1 Beam 31 33
3.3.3 Charged fragment 33
3.3.4 NEBULA 37
3.3.5 DALI2 38
3.4 Electronics 39
3.4.1 Trigger 39
3.5 Run summary 41
4. Analysis 52
4.1 Secondary beams 53
4.1.1 Time of flight (TOF) 53
4.1.2 Rigidity (Bρ) and energy loss (?E) 55
4.1.3 Particle identification 55
4.1.4 Beam profile 57
4.2 Charged fragments 64
4.2.1 Time of flight (TOF) and energy loss (?E) 65
4.2.2 Rigidity (Bρ) 66
4.2.3 Flight length 74
4.2.4 Particle identification 75
4.2.5 Momentum vector 77
4.3 Neutrons 78
4.3.1 Calibration 78
4.3.2 TOF and hit position 84
4.3.3 Pulse-height 89
4.3.4 Veto and clustering 90
4.3.5 Detection efficiency 94
4.4 Acceptance correction 99
4.4.1 Event generation 99
4.4.2 Evaluating acceptance 100
4.5 Fitting analysis 103
4.5.1 Response functions 104
4.5.2 Background functions 104
4.5.3 χ 2 distributions 106
4.6 Theoretical calculation 107
4.7 Systematic uncertainty 108
4.7.1 For relative energy 108
4.7.2 For cross section 108
5. Results 111
5.1 Relative energy spectrum 111
5.2 Cross section and parallel momentum distribution 114
6. Discussion 116
6.1 Level structure of 19C 116
6.2 Competition between ν0d 5/2 and ν1s 1/2 orbits 118
6.3 Deformation of 20Cg.s 120
7. Conclusion 122
A. List of materials 124
A.1 Sorts of Materials 125
A.1.1 Detector Materials 125
A.1.2 Non-Detector Materials 125
A.2 List of Materials 126
A.3 Flight Length 128
B. Geometry of the experimental setup 129
C. Run summary 131
D. Resolution of drift chambers 136
D.1 One-dimensional tracking 136
D.1.1 Error propagation 137
D.1.2 Relation between width of residual distribution and resolution 138
D.2 X-U-V tracking 138
D.3 Using experimental conditions 140
D.3.1 BDCs 140
D.3.2 FDC1 141
D.3.3 FDC2 141
E. Derivation of matrices for the dipole using optrace 142
E.1 Analysis of B-field 143
E.2 Input parameters 146
F. List of matrices for the dipole magnet 150
F.1 HOD module ID 1 150
F.2 HOD module ID 2 151
F.3 HOD module ID 3 151
F.4 HOD module ID 4 151
F.5 HOD module ID 5 152
F.6 HOD module ID 6 152
F.7 HOD module ID 7 152
F.8 HOD module ID 8 153
F.9 HOD module ID 9 153
F.10 HOD module ID 10 153
F.11 HOD module ID 11 154
F.12 HOD module ID 12 154
F.13 HOD module ID 13 155
F.14 HOD module ID 14 155
F.15 HOD module ID 15 156
F.16 HOD module ID 16 156
Bibliography 157
국문 초록 162
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dc.format.extentxiv, 163-
dc.language.isoeng-
dc.publisher서울대학교 대학원-
dc.subjectRI physics, neutron-rich nuclei, 19C, one-neutron knockout, invariant mass, unbound state, shell model-
dc.subject.ddc523-
dc.titleStudy of 19C by One-Neutron Knockout Reaction with a Carbon Target-
dc.title.alternative탄소 표적과 중성자 탈락 반응을 이용한 탄소-19 핵종에 대한 연구-
dc.typeThesis-
dc.typeDissertation-
dc.contributor.AlternativeAuthor황종원-
dc.contributor.department자연과학대학 물리·천문학부-
dc.description.degreeDoctor-
dc.date.awarded2015-08-
dc.contributor.major물리학전공-
dc.identifier.holdings000000000023▲000000000025▲000000067486▲-
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College of Natural Sciences (자연과학대학)Dept. of Physics and Astronomy (물리·천문학부)Physics (물리학전공)Theses (Ph.D. / Sc.D._물리학전공)
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