McCracken Garry - Fusion: the Energy of the Universe

These technical summaries, contained in shaded boxes, are supplements to the main text. They are intended for the more technically minded reader and may be bypassed by the general reader without loss of continuity.

Chapter 2

2.1 The Mass Spectrograph

Chapter 3

3.1 The Neutrino Problem

3.2 The Carbon Cycle

3.3 Cosmic Microwave Background Radiation

3.4 The Triple Alpha Process

3.5 Heavier Nuclei

Chapter 4

4.1 Source of Deuterium

4.2 Tritium Breeding Reactions

4.3 Conditions for Confinement

Chapter 5

5.1 Magnetic Confinement

5.2 Toroidal Confinement

5.3 Linear Confinement

Chapter 7

7.1 Conditions for Inertial Confinement

7.2 Capsule Compression

7.3 The Laser Principle

7.4 Capsule Design

7.5 Fast Ignition

Chapter 8

8.1 Electrolysis

Chapter 9

9.1 Disruptions

9.2 Sawteeth

9.3 Operating a Tokamak

9.4 Temperature Measurement

9.5 Sources of Impurities

9.6 Impurity Radiation

9.7 Production of Neutral Heating Beams

9.8 Radiofrequency Heating

9.9 L- and H-Modes

Chapter 10

10.1 Operating Limits

10.2 Pulse Length and Confinement Time

10.3 Understanding Confinement

10.4 Empirical Scaling

10.5 Stellarators

10.6 Magnetic Surfaces

Chapter 11

11.1 ITER Operating Limits

11.2 Some Changes Resulting from the 2007 Design Review

11.3 Additional Heating

Chapter 12

12.1 Advances in Target Design

12.2 Chirped-Pulse Amplification

12.3 Approaches to Ignition

Chapter 13

13.1 Steady-State versus Pulsed Power Plants

13.2 Radiation Damage

13.3 Low-Activation Materials

13.4 Shielding Superconducting Coils

13.5 Power Handling in the Divertor

13.6 The Broader Approach

13.7 Driver Efficiency and Target Gain

13.8 Diode-Pumped Lasers

13.9 Tritium Breeding

13.10 Alternative Fuels

The imperative for fusion energy grows stronger every year. Concerns increase regarding global climate change, conflicts over natural resources, safety of massively deployed energy production, and the finite supply of energy resources. The need for a safe, carbon-free, abundant energy source is intense. Fusion is one of the very few options for such an energy source.

Over the past fifty years, scientists have developed a new field of science: plasma physics. The core of a fusion energy system is a plasmaa gas of charged particleswhich is superhot, about ten times hotter than the core of the Sun. We now know how to produce, manipulate, and control this state of matter with remarkable finesse. The engineering and technology needed to control plasmas are also mature.

As a result of this fantastic accumulation of knowledge, fusion energy research is now at a turning point. With some reasonable clarity, we can see our way to the endpoint of commercial fusion energy. Both physics and engineering challenges surely remain. But the solutions to these challenges are sufficiently well-envisioned that roadmaps to fusion-on-the-grid have been developed in all nations active fusion research. Across the world, scientists draw a similar conclusion that a full-scale demonstration power plant can be operating in some 2025 years.

The current turning point is also marked by two new, landmark experimentsITER and NIF (the National Ignition Facility). ITER is an experiment in magnetic fusion energy, in which plasmas are confined by strong magnetic fields. Remarkably, the governments of half the worlds population have come together to design, construct, and operate the facility. ITER is designed, as an experiment, to generate about 500 million watts of fusion power for about 500 seconds. It will also produce, for the first time, a self-sustaining, burning plasma in which the plasma is self-heated by the power from the fusion reactions. ITER is under construction in Cadarache, France, and will begin operation around 2020. It will establish, to a large extent, the scientific and technological feasibility of a fusion power plant. NIF is an experiment in inertial fusion energy, recently brought into operation at the Lawrence Livermore National Laboratory in the US. NIF implodes a tiny pellet of frozen fusion fuel by immense lasers, causing a release of fusion energy in a fraction of a billionth of a second. Experiments are now underway to produce an ignited plasma in which fusion begins in the pellet core and propagates throughout the pellet.

This is an opportune moment to look back at the deep understanding of fusion plasma science that has accrued over the decades. This science has given us our designs of fusion power plants, but also has enormous impact on other fields of physics and technology, from the plasma cosmos to plasmas used to process computer chips. At this same moment, we can look ahead to how we will overcome the scientific hurdles to fusion. Thus, I am very pleased that the second, updated edition of this comprehensive and authoritative book by Garry McCracken and Peter Stott is now appearing, with new chapters on ITER and NIF.