lawrence livermore labs

anonymous asked:

Are there different kinds of ways to create fusion?

I’m glad you asked! Right now, there are two major experimental approaches for fusion being studied: magnetic confinement and inertial confinement.

In magnetic confinement fusion, the electrical conductivity of deuterium-tritium plasma is used to contain it within magnetic fields at a high pressure and heated to fusion temperature. Because the particles need to be repelled from the walls of a reactor (otherwise contact will dissipate their heat and slow them down), the most effective magnetic configuration is toroidal wherein the magnetic field is curved around and forms a closed loop. There are several different types of toroidal confinement systems but the most important are tokamaks and stellarators (reversed-field pinch devices would be next; however, plasma confinement in the best RFP is only about 1% as good as in the best tokamaks, owing largely to the fact that existing RFPs are very small).

Tokamak

Stellarator

In inertial confinement fusion, which is a newer line of fusion research, laser or ion beams are focused extremely precisely on a target - a pellet of deuterium-tritium fuel only a few millimeters in diameter. When the outer layer of the material is heated, it creates an outward explosion that generates an implosion that in turn compresses and heats the inner layers of material and results in conditions in which fusion can occur. The core of the fuel may be compressed to 1,000 times its liquid density and the energy released heats the surrounding fuel that may also undergo fusion, leading to a chain reaction (this is referred to as ignition) as the reaction spreads outward through the fuel. 

Large scale attempts at inertial confinement fusion include the Shiva laser built by Lawrence Livermore National Lab, followed by the Nova laser, the 24 beam OMEGA laser and the Novette Laser, which all paved the way for the National Ignition Facility in Livermore, California.

Light Observed as Particle and Wave at the Same Time

by Txchnologist staff

Since physicists at the beginning of the 20th century realized the dual nature of light–that it simultaneously exists as a particle and a wave–they have been hungry to see both aspects at the same time. Now, more than 100 years after the work of Max Planck, Albert Einstein and others began uncovering wave-particle duality, scientists in Switzerland say they have done it. 

The picture above, taken in the lab of Fabrizio Carbone at the Swiss Federal Institute of Technology in Lausanne, shows light from a laser that was trapped on a nanoscopic silver wire. By capturing the wave along the length of the nanowire, the researchers were able to discern the standing electromagnetic wave through spatial interference patterns. 

Then they fired electrons at the wire in an attempt to interact with the particles that make up light, which are called photons. The scientists were able to visualize the photons by measuring the exchange of energy when the electrons hit them. Using a large, specialized microscope, the team watched where the energy exchange happened along the standing wave trapped on the wire. 

The photo that resulted, they said, shows both a wave of light and individual photons. See more images and read more below.

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