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Conduction Electrons in Magnetic Metals

The conduction electrons in magnetic metals are sometimes themselves responsible for the magnetism, as in the 3d transition metals, and sometimes are magnetic intermediaries, as in the rare earths. In both cases the calculated magnitude of the exchange interactions is now in good agreement with experiment. The effect of magnetism upon the crystal structu ...

Electromagnetic Force Distribution Inside Matter

Using the Finite Difference Time Domain method, we solve Maxwell's equations numerically and compute the distribution of electromagnetic fields and forces inside material media. The media are generally specified by their dielectric permittivity ε (ω) and magnetic permeability µ(ω), representing small, transparent dielectric and magnetic objects such as p ...

Mineral Commodity Profiles Rubidium

Rubidium is a soft, ductile, silvery-white metal that melts at 39.3 o C. One of the alkali metals, it is positioned in group 1 (or IA) of the periodic table between potassium and cesium. Naturally occurring rubidium is slightly radioactive. Rubidium is an extremely reactive metal—it ignites spontaneously in the presence of air and decomposes water explos ...

Nuclear Fusion

Nuclear fusion is an attractive long-term energy solution, although it is unlikely that the technology will be ready for commercial power generation in the near future. Fusion is the process that produces the light and heat of the sun. Hydrogen nuclei collide in the sun’s core and release huge amounts of energy as they fuse into helium atoms. On Earth, f ...

Determination of the Hyperfine Coupling Constant of the Cesium 7S1/2 State

We report the hyperfine splitting (HFS) measurement of the cesium (Cs) 7S1/2 state by optical-optical double-resonance spectroscopy with the Cs 6S1/2-6P3/2-7S1/2 (852 nm + 1470 nm) ladder-type system. The HFS frequency calibration is performed by employing a phase-type waveguide electro-optic modulator together with a stable confocal Fabry-Perot cavity. ...

The Mossbauer Effect: Hyperfine Splitting

Experiment 28 introduced you to the method of using the Mössbauer Effect to enable gamma ray emission and subsequent absorption by nuclei embedded in solid crystals. You obtained an absorption line spectrum of the 14.4keV gamma ray emitted by iron-57 (the daughter nucleus following a cobalt-57 beta decay) and subsequently absorbed by another 57Fe nucleus ...

Geology

This Chapter supplements and expands upon Chapter 5 of the GEIS. Sections 4.1 through 4.5 and the accompanying figures and tables were provided in their entirety by Alpha Environmental, Inc., under contract to NYSERDA to assist the Department with research related to this SGEIS.1 Alpha’s citations are retained for informational purposes, and are listed i ...

Ion Implantation in Silicon Technology

I on implanters are essential to modern integrated-circuit (IC) manufacturing. Doping or otherwise modifying silicon and other semiconductor wafers relies on the technology, which involves generating an ion beam and steering it into the substrate so that the ions come to rest beneath the surface. Ions may be allowed to travel through a beam line at the e ...

Best Practice in Nuclear Medicine

Nuclear Medicine departments offer a large diversity of diagnostic and therapeutic procedures, which often play a central role in patient management. At the same time, the field is constantly evolving with new procedures being continuously introduced. In such a rich and developing scenario, adherence to bestpractice guidelines becomes crucial to offer be ...

Nonstrategic Nuclear Weapons

Recent debates about U.S. nuclear weapons have questioned what role weapons with shorter ranges and lower yields can play in addressing emerging threats in Europe and Asia. These weapons, often referred to as nonstrategic nuclear weapons, have not been limited by past U.S.- Russian arms control agreements, although some analysts argue such limits would b ...

The History of Nuclear Energy

Although they are tiny, atoms have a large amount of energy holding their nuclei together. Certain isotopes of some elements can be split and will release part of their energy as heat. This splitting is called fission. The heat released in fission can be used to help generate electricity in powerplants. Uranium-235 (U-235) is one of the isotopes that fis ...

Quantum Theory of the Atomic Nucleus

It has often been suggested that non–Coulomb attractive forces play a very important role inside atomic nuclei. We can make many hypotheses concerning the nature of these forces. They can be the attractions between the magnetic moments of the individual constituents of the nucleus or the forces engendered by electric and magnetic polarization. In any cas ...

Review of Lepton Universality Tests in B Decays

Several measurements of tree- and loop-level b-hadron decays performed in the recent years hint at a possible violation of Lepton Universality. This article presents an experimental and theoretical overview of the current status of the field.

Photovoltaics Value Analysis

Now is the time to plan for the integration of significant quantities of distributed renewable energy into the electricity grid. Concerns about climate change, the adoption of state-level renewable portfolio standards and incentives, and accelerated cost reductions are driving steep growth in U.S. renewable energy technologies. The number of distributed ...

Photonics and Optoelectronics

Silicon photonics has garnered a large amount of interest in recent years due to its potential for high data transfer rates and for other, more novel applications. One attractive feature of silicon photonics is its relatively seamless integration with existing CMOS fabrication technologies. That means, however, that it is subject to similar random and sy ...

Quantum Electronics

If you have ever used a pocket caJculator, you probably could riot help but be amazed how something so small can be so smart-and so fast. In fact, the smallness is even more impressive when looking beyond what meets the eye. The actual brains of these calculators, integrated circuits, are made of silicon tran294 THE WORLD & I sistors too small to be seen ...

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