Nuclear Fusion with Polarized Fuel (eBook)

Giuseppe Ciullo is a Professor at the Department of Physics and Earth Sciences, Ferrara University, Italy. He previously undertook a fellowship at the national laboratory LNL-INFN (1994–96) and was a researcher at CeFSA – CNR (1996–2000). His recent interests include polarized nuclear targets and their use in fundamental nuclear physics in different experimental collaborations: HERMES, OLYMPUS, PAX, JEDI TRIC, and PolFusion. Ralf Engels has been a scientific staff member of the Institute for Nuclear Physics (IKP), Research Center Jülich, Germany, since 2006. He obtained his PhD from the University of Cologne in 2002 before working as a postdoc at IKP. His interests are polarized targets, ion sources, and polarimeters for experiments at accelerators. In parallel, he is using a Lamb-shift polarimeter for atomic and molecular physics. He is a member of ANKE, WASA, PAX, JEDI, BOB, and the PolFusion collaboration. Markus Büscher is a Professor at the Institute for Laser and Plasma Physics, Heinrich Heine University, Düsseldorf, Germany and a staff member at the Peter-Grünberg Institut (PGI-6), Research Center Jülich, Germany. His recent research activity has included experiments on laser-induced particle acceleration and experiments with the WASA spectrometer at COSY. He is a member of the ANKE/COSY, PANDA/HESR, and WASA-at-COSY collaborations. Alexander Vasilyev is Head of the Cryogenic and Superconductive Technique Laboratory of the National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute, Russia. He is also Deputy Head of the High-Energy Physics Department at the Institute. His interests are polarized gas targets, cryogenic targets, ions, and atomic beams. He is a spokesperson for the MuSun collaboration (PSI, Switzerland) and a member of the PolFusion collaboration. 

Foreword 6
Contents 8
Contributors 10
Acronyms 13
1 Polarized Fusion: An Idea More Than Thirty Years Old! What Are We Waiting For? 15
1.1 The Climate Policy Paradigma 15
1.1.1 The 2 Degrees Scenario: 2DS 17
1.1.2 Energy Panorama Requires Nuclear Resources: Most Comfortable Solution Is Nuclear Fusion 18
1.2 Towards Nuclear Fusion with Polarized Fuel 19
1.2.1 Fusion with Polarized Fuel: Advantages 20
1.2.2 The PolFusion Collaboration Challenges on D: Towards Polarized Fuel and Spin Dependent Cross Section 22
1.2.3 Fusion with Polarized Fuel: Open Questions 23
1.2.4 Correlated Activities of Interest for Polarized Nuclear Fusion 24
1.3 Conclusion 26
References 26
2 Spin Physics and Polarized Fusion: Where We Stand 28
2.1 ``Polarized'' Fusion 28
2.1.1 Fusion Basics 29
2.1.2 Nuclear Cross-Sections 29
2.2 Five-Nucleon Fusion Reactions 31
2.3 Four-Nucleon Reactions 34
2.3.1 Suppression of Unwanted D + D Neutrons 35
2.3.2 Formalism and Theory of the D + D Reactions 35
2.3.3 Possible Reaction-Rate Enhancement for the D + D Reactions by Polarization? 39
2.4 Present Status of ``Polarized'' Fusion 39
2.5 New Calculations for Few-Body Systems 40
2.5.1 Theoretical Approaches 40
2.5.2 Effect of Electron Screening 41
2.6 New Aspects of Polarized Fusion 41
2.6.1 Rate Enhancement and Electron Screening 42
2.6.2 Pellet Implosion Dynamics 43
2.6.3 Technical Questions 43
2.6.4 Preservation of Polarization on Injection 44
2.7 Summary and Conclusions 44
References 46
3 The PolFusion Experiment: Measurement of the dd-Fusion Spin-Dependence 48
3.1 Introduction 48
3.2 Polarization Phenomena in Few-Body Systems: Theory and Experiment 50
3.3 Experimental Setup 52
3.4 Test Measurement and Software Development 55
3.5 D--d and d--d Fusion Reaction 56
References 57
4 Hyper-Polarized Deuterium Molecules: An Option to Produce and Store Polarized Fuel for Nuclear Fusion? 58
4.1 Introduction 59
4.2 Apparatus 60
4.3 First Results 62
4.4 Predictions for Deuterium 64
4.5 Conclusion 66
References 67
5 A Polarized 3He Target for the Exploration of Spin Effects in Laser-Induced Plasmas 68
5.1 Introduction 69
5.2 Polarized 3He as Possible Polarized 3He--Ion Source 70
5.3 Magnetic Holding Field 72
5.3.1 Helmholtz--coil Array 72
5.3.2 Halbach Array 73
5.4 Gas--Jet Source 74
5.4.1 Required Particle Density 75
5.4.2 Pressure Booster 77
5.4.3 Fast-Opening Valve 78
5.5 Polarimetry 79
5.6 Outlook 80
References 80
6 Relevant Spatial and Time Scales in Tokamaks 82
6.1 Introduction 82
6.2 Thermonuclear Fusion in Tokamaks 83
6.3 Relevant Time Scales 86
6.4 Fuelling Requirements 87
6.5 Ion Cyclotron Resonant Heating and Plasma Polarization 87
6.6 Conclusions 90
References 91
7 Depolarization of Magnetically Confined Plasmas 92
7.1 Introduction 93
7.2 Spin Polarized D--T Magnetic Fusion 94
7.3 The Depolarization Problem 95
7.4 Depolarization Mechanisms 96
7.4.1 Binary Collisions 97
7.4.2 Static Inhomogeneous Magnetic Field 98
7.4.3 Magnetic Fluctuations 98
7.4.4 Conclusions 99
7.5 Collective Mode Driven by ?-Particles 100
7.5.1 Normal Modes in an Homogeneous Plasma 100
7.5.2 Mode Growth 104
7.5.3 Normal Modes in an Inhomogeneous Plasma (Qualitative Discussion) 109
7.5.4 Precession Resonance and Depolarization Rate 111
7.5.5 Compact, High-Field Tokamaks 113
7.5.6 Different Spin Polarization Modes 114
7.5.7 Conclusions 115
7.6 Summary and Conclusions 115
Appendix 1 117
Appendix 2 117
References 118
8 Ion Polarization in Magnetic Fields 119
8.1 Introduction 119
8.2 Polarization Survival in the Plasma 120
8.3 Spin Motion in a Reactor's Field 121
8.4 ICRH in a Tokamak 123
8.5 ICRH and Polarization 124
8.6 Conclusion 125
References 126
9 Prospects for Direct In Situ Tests of Polarization Survival in a Tokamak 127
9.1 Introduction 128
9.2 Polarization-Dependent Fusion Reactions 129
9.3 Potential Impacts in Large Scale Machines 132
9.4 Depolarization Mechanisms in Large and Research-Scale Tokamaks 134
9.5 Testing Fuel Polarization Survival in a Research Tokamak 135
9.6 Background Reactions and Detection Strategy 139
9.7 Options for Polarized Fusion Tests in European Tokamaks 140
References 141
10 DD Fusion from Laser Interaction with Polarized HD Targets 143
10.1 Introduction 143
10.2 Method 145
10.3 Target 145
10.4 Fusion Process 147
10.5 Signature of the Polarization Persistency 148
10.6 Other Approaches 149
10.7 Conclusion 149
References 150
11 Polarization of Molecules: What We Can Learn from the Nuclear Physics Efforts? 151
11.1 Introduction 151
11.2 Sources of Polarized Hydrogen Isotopes 152
11.3 Source of Polarized Molecules 153
11.4 Conclusions 155
References 155
12 RF Negative Ion Sources and Polarized Ion Sources 157
12.1 Introduction: Negative Ion Sources 157
12.2 Gas Kinetics and Dynamics in the Expansion Region 159
12.3 Plasma Kinetics and Dynamics in the Expansion Region 160
12.4 Polarized Ion Atomic-Beam Sources 162
12.5 Conclusions 164
References 164
Index 165