Atomfysik og molekylær fysik

While neutron halos were discovered 30 years ago, this is the first book written on the subject of this exotic form of nuclei that typically contain many more neutrons than stable isotopes of those elements. It provides an introductory description of the halo and outlines the discovery and evidence for its existence. It also discusses different theoretical models of the halo's structure as well as models and techniques in reaction theory that have allowed us to study the halo. This is written at a level accessible to graduate students starting a PhD in nuclear physics. Halo nuclei are an exotic form of atomic nuclei that contain typically many more neutrons than stable isotopes of those elements. To give you a famous example, an atom of the element lithium has three electrons orbiting a nucleus with three protons and, usually, either 3 or 4 neutrons. The difference in the number of neutrons gives us two different isotopes of lithium, Li6 and Li7. But if you keep adding neutrons to the nucleus you will eventually reach Li11, with still 3 protons (that means it's lithium) but with 8 neutrons. This nucleus is so neutron-rich that the last two are very weakly bound to the rest of the nucleus (a Li9 core). What happens is a quantum mechanical effect: the two outer neutrons float around beyond the rest of the nuclear core at a distance that is beyond the range of the force that is holding them to the core. This is utterly counterintuitive. It means the nucleus looks like a core plus extended diffuse cloud of neutron probability: the halo. The author of the book, Jim Al-Khalili, is a theoretician who published some of the key papers on the structure of the halo in the mid and late 90s and was the first to determine its true size. This monograph is based on review articles he has written on the mathematical models used to determine the halo structure and the reactions used to model that structure.

This book focuses on the multifluid theory in the field of magnetically confined plasma physics. It is an advanced review on the state-of-the-art theory and application of magnetically confined plasma physics.

A fun, dazzling exploration of the strange numbers that illuminate the ultimate nature of reality.For particularly brilliant theoretical physicists like James Clerk Maxwell, Paul Dirac, or Albert Einstein, the search for mathematical truths led to strange new understandings of the ultimate nature of reality. But what are these truths? What are the mysterious numbers that explain the universe? In Fantastic Numbers and Where to Find Them, the leading theoretical physicist and YouTube star Antonio Padilla takes us on an irreverent cosmic tour of nine of the most extraordinary numbers in physics, offering a startling picture of how the universe works. These strange numbers include Graham's number, which is so large that if you thought about it in the wrong way, your head would collapse into a singularity; TREE(3), whose finite nature can never be definitively proved, because to do so would take so much time that the universe would experience a Poincaré Recurrence-resetting to precisely the state it currently holds, down to the arrangement of individual atoms; and 10^{-120}, measuring the desperately unlikely balance of energy needed to allow the universe to exist for more than just a moment, to extend beyond the size of a single atom-in other words, the mystery of our unexpected universe.Leading us down the rabbit hole to a deeper understanding of reality, Padilla explains how these unusual numbers are the key to understanding such mind-boggling phenomena as black holes, relativity, and the problem of the cosmological constant-that the two best and most rigorously tested ways of understanding the universe contradict one another. Fantastic Numbers and Where to Find Them is a combination of popular and cutting-edge science-and a lively, entertaining, and even funny exploration of the most fundamental truths about the universe.

This book gives students and instructors a full exploration of Bohr's model of the atom. Topics covered include the historical background and Bohr's approach to his original derivation. It also includes student exercises, a bibliography, a list of important physical constants, and a survey of Bohr's subsequent life and career.