Synthesis of Super-Heavy Elements: Role of Uncertainty Analysis in Theoretical Modeling Hongliang Lu

Synthesis of Super-Heavy Elements: Role of Uncertainty Analysis in Theoretical Modeling Hongliang Lu To cite this version: Hongliang Lu. Synthesis of Super-Heavy Elements: Role of Uncertainty Analysis in Theoretical Modeling. Nuclear Theory [nucl-th]. Universitéde Caen Normandie, 2015. English. <tel- 01235448> HAL Id: tel-01235448 http://hal.in2p3.fr/tel-01235448 Submitted on 30 Nov 2015 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinéeau dépôtet àla diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiésou non, lished or not. The documents may come from émanant des établissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou étrangers,des laboratoires abroad, or from public or private research centers. publics ou privés. Université de Caen Normandie U.F.R. de Sciences École Doctorale SIMEM Thèse de doctorat présentée et soutenue le : 18/11/2015 par Monsieur Hongliang LÜ pour obtenir le Doctorat de l’Université de Caen Normandie Spécialité : Constituants élémentaires et physique théorique Synthèse des noyaux super-lourds : Rôle de l'analyse d'incertitude dans la modélisation MEMBRES du JURY : M. D. ACKERMANN Akademische Direktor, GSI, Darmstadt, Allemagne (Rapporteur) M. G. ROYER Professeur, Université de Nantes, Nantes (Rapporteur) Mme F. GULMINELLI Professeur, Normandie Université, Caen (Présidente du jury) Mme B. JURADO Chargée de recherche, GENBG, Gradignan (Examinatrice) M. A. CHBIHI Directeur de recherche, GANIL, Caen (Directeur de thèse) M. D. BOILLEY Maître de conférence, Normandie Université, Caen (Encadrant) GANIL T 2015 03 If a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts he shall end in certainties. — Francis Bacon To my parents and all my family . Acknowledgements How time flies! Three years have passed in the blink of an eye ... Standing at this turning point, so many pieces of memories come to mind. There are many people to whom I owe a debt of thinks for making my Ph.D. experience so fruitful. First of all, I would like to express my sincere gratitude to the director of GANIL, Florent Staley, for giving me the opportunity to carry out my research project in theoretical nuclear physics at the GANIL laboratory. Then, I would like to thank Dr. Dieter Ackermann and Prof. Guy Royer for having accepted to be the referees of this thesis. I am also grateful to the other committee members, Prof. Francesca Gulminelli and Dr. Beatriz Jurado. Finally, let me express my deepest and sincere gratitude to my supervisors, Dr. Abdelouahad Chbihi and Dr. David Boilley, for their enlightening guidances and having faith in me. I would like to specially thank David, to whom I owe a special debt for all his support and help over the past years and for giving me the confidence as well as the independence that are indispensable for doing scientific research. When I was stuck somewhere in my work, he was always able to set me on the right track with his exceptional insight and depth of knowledge. Many thanks to our collaborators, without whom, this Ph.D. work would never have been achieved. First, I would like to extend my heartfelt gratitude to the amiable Prof. Yasuhisa Abe, whose reputation as an excellent physicist precedes him and with whom I had many fruitful discussions. I would also like to thank him for the invitation to Japan, which allowed me to get involved in a long-lasting scientific collaboration. Then, I am very grateful to Prof. Caiwan Shen for his support and help when I stayed at Huzhou University, and for teaching me how to use his code for studying heavy-ion fusion. I was really impressed by his warm welcome, his kindness as well as his patience. In addition, I am deeply indebted to Dr. Anthony Marchix for his attention and the numerous discussions about the development of a computer code which served as the basis for my Ph.D. work. Without his help, this thesis would never have achieved its current form. Finally, I will never forget Dr. Yoann Lallouet and would like to thank him for his help at the beginning of my research project. And now, my sincere gratitude and appreciation go to all my colleagues working at the GANIL laboratory. It is quite hard to enumerate all of them in a few lines ! Thanks to Pieter Van Isacker and Marek Płoszajczak, whose culture and erudition never cease to impress me. I would also like to thank them for kindly inviting me to attend the Talent Course, which i turned out to be an unforgettable experience during my Ph.D. thesis. Thanks to François de Olivera for sharing his knowledge and enthusiasm for astrophysics and also giving me helpful advice for my post-doc. I am deeply grateful to Beyhan Bastin and Julien Piot for inviting me to get involved in an experimental project at the beginning of my thesis. I am also grateful to the present leader of the physics group, Fanny Farget, for her attention and appreciation on my Ph.D. work. I would also like to express my deep sorrow over the passing away of Mr. Jean-Francois Libin, who was passionate about Chinese culture, and my heartfelt thanks for the invitation to visit his precious collections, the snuff bottles, and to lunch at his house. May his soul rest in peace. Finally, I would like to express my deepest gratitude to all the permanent stuff of the GANIL, Gilles de France, Christelle Stodel, Virginie Lefebvre, Sabrina Lecerf-Rossard, Christine Lemaître, Nicolas Ménard, Michel Lion ... for helping or supporting me in different ways during the past three years. I thought I was lucky to have chance to work in such a homelike environment. Over the past three years, I also had chance to meet many Ph.D. students or post-docs, with whom I shared lots of great moments. Thanks to Igor, Guillaume, Olivier, Yannen, Paola, Mark, Danilo, Carme, Haïfa, Jose, Marija, Alexis, Kévin, Florent, Pierre, Mathieu, Quentin, Dennis, Nicolas, Bortholmé, Guoxiang, Kosuke, Kazuyuki, Yongjia, Chenchen, Hai, Min, Yunghee ... Thanks to my first office mate, Igor, for the nice moments we shared together during the first year. Thanks to Marija for reading part of the manuscript and her useful comments. Special thanks to my current office mates, Pierre and Kosuke, for their friendship. And also to Mathieu, it will always be my great pleasure to be your tour guide if you still plan to travel to China someday. Sincere thanks to Kévin and Guillaume for their help in solving some physics or numerical problems. I am also grateful to Kazuyuki for kindly guiding me on my trip to Tokyo. I will never forget Yongjia, Chenchen and Hai, for their kindly help when I stayed in Shenzhen and Huzhou, and I miss lots of moments of fun we shared together during the two months. Finally, best wishes to Bartholomé for the rest of his Ph.D. work. I would like express my gratitude to Prof. Olivier Juillet for accepting me to spend some time teaching at the University of Caen. I am also grateful to Jean-Christophe Poully, Michaël Fromager,Alain Mery and Julie Douady for their help in preparing the practical works. Thanks to Prof. François Mauger, for whom I have a lot of admiration and also for many helpful discussions concerning numerical methods. Before the end of this acknowledgements section, a special gratitude and love goes to my parents for their eternal support and great encouragement over the past years, especially during the tough times in my research. I would also like to extend my deepest gratitude to all my family and friends. Hongliang LÜ GANIL September 2015 ii Contents Acknowledgements i I Introduction en français 1 II Conclusions et perspectives 5 III General introduction 9 IV Heavy-ion fusion 15 IV.1 Capture Step . 16 IV.1.1 Coupled-channels description . 17 IV.1.2 Empirical barrier-distribution method . 21 IV.1.3 Semi-classical method: one-dimensional model . 22 IV.1.4 Uncertainty estimation for capture models . 24 IV.1.5 Summary . 34 IV.2 Formation step . 34 IV.2.1 Radial evolution . 37 IV.2.2 Neck formation . 40 IV.2.3 A simple two-dimensional model . 42 IV.2.4 Approximation limits . 47 IV.3 Two-step model . 48 IV.3.1 Brief review . 48 IV.3.2 Application to the fusion reaction: 129Xe+nat Sn............... 50 IV.4 Summary and conclusions . 54 V Statistical decay of excited nuclei 57 V.1 Brief introduction . 57 V.2 Numerical framework for compound-nucleus decay . 59 V.2.1 Single chain . 60 V.2.2 Multi-channel scheme . 62 V.2.3 Numerical scheme . 63 V.3 Light-particle evaporation and γ-ray emission . 66 V.3.1 Detailed balance . 66 V.3.2 Weisskopf-Ewing model . 67 iii Contents V.3.3 Hauser-Feshbach formalism . 67 V.3.4 γ-ray emission . 70 V.4 Nuclear fission . 75 V.4.1 Fission barrier . 77 V.5 Nuclear level density . 79 V.5.1 Intrinsic state-density formula . 79 V.5.2 Level-density parameter . 80 V.5.3 Moment of inertia . 81 V.5.4 Ignatyuk’s prescription . 82 V.5.5 Collective enhancement factor . 82 V.5.6 Pairing effect . 83 V.6 Computational examples and sensibility analysis . 83 208 16 224 x V.6.1 Reaction Pb( O,xn) ¡ Th......................... 84 238 16 254 x V.6.2 Reaction U( O,xn) ¡ Fm......................... 86 208 48 256 x V.6.3 Reaction Pb( Ca,xn) ¡ No.......................

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