confinementquarks

...it is not one quark but a quark-antiquark pair that is “pulled” from a cluster. Thus, quarks appear always to be locked inside the observable mesons and baryons, a phenomenon known as confinement. At distances comparable to the diameter of a proton, the strong interaction between quarks is about 100 times greater than the electromagnetic interaction. At smaller distances, however,...

As use of the new type of prison expanded, administrators began to experiment with new methods of prisoner rehabilitation. Solitary confinement of criminals came to be viewed as an ideal, because it was thought that solitude would help the offender to become penitent and that penitence would result in rehabilitation. In the United States the idea was first implemented at Eastern State...

In an inertial confinement fusion (ICF) reactor, a tiny solid pellet of fuel—such as deuterium-tritium (D-T)—would be compressed to tremendous density and temperature so that fusion power is produced in the few nanoseconds before the pellet blows apart. The compression is accomplished by focusing an intense laser beam or a charged particle beam, referred to as the driver, upon the...

...are in progress in the United States to develop, upgrade, and integrate weapons into warhead programs and to explore advanced concepts for future weapons systems. A concept of particular interest is inertial-confinement fusion. This program is directed at determining the feasibility of burning very small pellets of thermonuclear fuel using laser or particle-beam drivers. The program is of...

Work on the other major approach to fusion energy, inertial confinement fusion (ICF), was begun in the early 1960s. The initial idea was proposed in 1961, only a year after the reported invention of the laser, in a then-classified proposal to employ large pulses of laser energy (which no one then quite knew how to achieve) to implode and shock-heat matter to temperatures at which nuclear fusion...

In this approach, a fuel mass is compressed rapidly to densities 1,000 to 10,000 times greater than normal by generating a pressure as high as 1017 pascals (1012 atmospheres) for periods as short as a nanosecond (10−9 second). Near the end of this time period, the implosion speed exceeds about 3 × 105 metres per second. At...

ICF research has followed an...

In magnetic confinement the particles and energy of a hot plasma are held in place using magnetic fields. A charged particle in a magnetic field experiences a Lorentz force that is proportional to the product of the particle’s velocity and the magnetic field. This force causes electrons and ions to spiral about the direction of the magnetic line of force, thereby confining the particles. When...

...It is not possible to assemble on Earth a plasma sufficiently massive to be gravitationally confined. For terrestrial applications, there are two main approaches to controlled fusion—namely, magnetic confinement and inertial confinement.

Several decades of fusion research have produced accomplishments of two types. First, the discipline of plasma physics has developed to the point that theoretical and experimental tools permit quantitative evaluation of many aspects of fusion reactor concepts. Second, and perhaps most revealing, the evolutionary improvement of plasma parameters has placed experiments at the threshold of...

An alternative approach to magnetic confinement is to employ a straight configuration in which the end loss is reduced by a combination of magnetic and electric plugging. In such a linear fusion reactor the magnetic field strength is increased at the ends. Charged particles that approach the end slow down, and many are reflected from this “magnetic mirror.” (The same magnetic...