China
Africa
Explore chapters and articles related to this topic
Radioisotope Production and Application
Published in Paul R. Bolton, Katia Parodi, Jörg Schreiber, Applications of Laser-Driven Particle Acceleration, 2018
Although meaningless for our diagnostic application, the neutrino is basic for understanding the energy balance and originates a distribution of positron energies, instead of a well-defined, single energy value. The positron energy spectrum is relevant, because the mean free path of the positrons inside the body depends on their energy. Fortunately, the mean free path is very small (a few millimetres) so the blurring is acceptable for most tracers. In general, it is very difficult to resolve the internal organs in a PET image, and so it is desirable to combine it with conventional X-ray CT [Wolbarst 2006]. PET/CT systems are common. The patient goes through the PET ring and immediately after through the CT, all on the same motorized stretcher. Since recently the PET/MR combination is also possible. The most relevant characteristic of PET is that coincidence detection improves significantly the signal-to-noise ratio. Of course, PET, PET/CT and all other kinds of similar medical imaging techniques need a very specific expertise to provide a sharp interpretation [Fanti 2010, Conti 2016]. From a physicist’s point of view, PET has the appealing feature of a medical use of antimatter.
Neutrons and Other Important Nuclear Particles
Published in Robert E. Masterson, Nuclear Engineering Fundamentals, 2017
Today, we know that the position is an example of a much larger family of particles that are called “antimatter” particles today. If you are studying nuclear engineering, you have probably heard of the term “antimatter” before. Antiparticles also have the opposite lepton and baryon numbers (i.e., their numbers have the opposite sign) than matter particles do. These particles are created in many nuclear reactions, usually as particle and antiparticle pairs. Antimatter is created on a miniscule scale in nuclear reactors today—primarily in the form of positrons that are emitted in the process of beta decay. These particles are called “antimatter” particles because whenever they encounter normal matter particles of the same kind, they instantly annihilate each other, giving off a huge amount of energy in the process. This energy is again carried away by the photon in the form of vibrational energy, because the photon allows us to conserve energy, momentum, and charge. Particles of antimatter are always identical to the matter particles that are their mirror images in the physical world. As far as we can tell, the only difference between matter and antimatter is that particles of antimatter have an entirely opposite set of quantum properties than their material counterparts do.
The evolution of future societies with unlimited energy supply?
Published in Kléber Ghimire, Future Courses of Human Societies, 2018
Currently, there are certain forms of energies that are only known theoretically. We neither understand them properly, nor do we have the proper tools to build devices that can be used to produce energy. Among these types of energies, the energy produced by antimatter is one of the most intriguing. Antimatter is a material composed of antiparticles. Those antiparticles are exactly the same as normal matter; the only difference is that they have an opposite electronic charge. In antimatter the antiproton has the same mass as the proton but will be charged with opposite negative electric charge, and the antielectron has the same mass as the electron but would have a positive charge. Theoretically, a collision between a particle and an antiparticle leads to their mutual annihilation resulting in the production of pure energy. The amount of energy is regulated by Einstein’s equation E=mc2, where the mass is the mass of the two particles involved in the collision. Just as ordinary particles, antimatter particles bind with one other to form antimatter atom, therefore it is theoretically possible to have a Mendeleyev table of antiatom elements. The Mendeleyev table or periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number (number of protons), electron configurations, and recurring chemical properties. Thus, one of the great unsolved problems in physics today is the following: why is the observable universe composed of ordinary matter only? The antimatter in the form of antiatoms is one of the most difficult materials to produce, let alone to confine in a reactor. Supposing that we will be able in the future to produce antimatter, how can we store the antimatter safely? Our planet and we are built of matter, and therefore will annihilate instantaneously when in contact with antimatter.
New frontiers in computing and data analysis – the European perspectives
Published in Radiation Effects and Defects in Solids, 2019
The high-luminosity large hadron collider (HL-LHC) (the upgrade of LHC) will support the investigation of the properties of the Higgs boson and its couplings to other particles. The ATLAS (A Toroidal LHC ApparatuS) (5) and CMS (Compact Muon Solenoid) (6) experiments will continue to make measurements in the Higgs sector and will search for new physics beyond the standard model (BSM). The LHCb experiment will study various aspects of heavy flavor physics (b- and c-quark, and tau-lepton physics) to investigate the BSM physics. The study of neutrinos, their mass and oscillations, will also shed light on matter–antimatter asymmetry. These experimental programs require large investments in detector hardware to support building new facilities and experiments and to upgrade LHC in a new generation phase of high luminosity.