The field of high energy physics deals with the elementary constituents of matter and energy, interaction between the particles and nature of space-time. The primary focus of this field is the study of heavy ions collisions to get the minute mass particles from the gigantic particle accelerators. Particle accelerator uses electromagnetic field to propel charged particles nearly in to the speed of light and confined them in well defined beam. These accelerators are called collider. CERN’s Large Hadrons Collider (LHC), the world’s largest collider, is one of the several particle accelerators around the world. LHC operates one month a year in the nuclear collision mode with Pb(lead)-nuclei colliding at very high temperature and energy by which very strongly interacting particles are generated.
High energy physics will provide a better understanding of how the universe works?, potentially answering the questions like why is the Higgs(particle assumed to give all the mass of the universe)mass is so light? what is the dark matter made up of?Are all the forces unified in to one force at high energy? etc. The study of the elementary particles of astronomical origin and their relation to astrophysics and cosmology is also associated with high energy physics or particle physics. This study is termed as astroparticle physics. Proton-Proton collision at the Large Hadrons Collider-LHC at CERN occurs at energy of 1012 eV where a cosmic ray spectrum which is found freely in space contain particles with energies as high as 1020 eV, due to this reason astroparticle physics is very necessary for the study of high energy. It is difficult to producing a particle with energy comparable to those found in space.
Fusion process is a nuclear reaction which powers the sun and stars as hydrogen atoms fuse together to form helium, and matter is converted into energy.
Image: Fusion Process
Hydrogen, heated to very high temperatures changes from a gas to plasma in which the negatively-charged electrons are separated from the positively-charged atomic nuclei (ions). Normally, fusion process is not easily possible because the strongly repulsive electrostatic forces between the positively charged nuclei prevent them from getting close enough together to collide and for fusion to occur. when the temperature increases, causing the ions to move faster and eventually reach speeds high enough to bring the ions close enough together. The nuclei can then fuse, causing a release of high energy. In the Sun, massive gravitational forces create the right conditions for fusion, but on earth they are much harder to achieve.
Nuclear Fusion: high energy lasers (Image http://muonray.blogspot.com/)
Nuclear fusion has the potential to produce nearly unlimited supplies of clean, safe, carbon free energy. Like sun and stars it can be realized in reactors that simulates the condition of ultra hot diminutive “Stars” of plasma. May all we know that, 99% of mass of the universe is made by matter composed of quarks and gluons. Most of this matter is found at the core of atoms, the same atom that embrace all we see around us (including ourselves).
We have seek to understand how the universe evolved just after the big bang from super hot plasma of quarks and gluons, how the different elements of the universe were formed, and how a nucleus is made up of individual protons and neutrons interacting with each other with the strongest force in nature. At the core of the sun, nuclear fusion reaction takes place at very high temperature which is possible by plasma state only. Nuclear fusion reaction that occurs in sun and star creates heavier elements from lighter one. If such kind of energy source that can be created from fusion process can be harnessed at the human scale it has the advantage of inexhaustible fuel resources and greatly reduced proliferation and environmental concerns. Till now, fusion reaction takes place only at temperature comparable to the center of sun so implementing the fusion reactor involves the development of techniques to creates and confine the tremendous hot ionized, “Plasma” state of matter. To make fusion feasible on the earth surface, the plasma must be very hot (More than 50 million degree) it must be stable under the intense pressure and it must be contained in a fixed volume. Successful fusion also requires that the product of three factor- plasmas particle density, its confinement time, and its temperature reaches a certain value.
Higgs Boson, also called god particle or quark –gluon plasma (QGP), widely considered being the fundamental particle for all the mass of the universe. This computer simulation showing particle tracks inside the LHC’s detector after Higgs boson decay. (Image: CERN)
In June 2015, an international team of physicist produced quark –gluon plasma (QGP) at LHC, CERN by colliding proton with lead nuclei at very high energy. This quark –gluon plasma (QGP) is hypothesized to exist at extremely high temperature and density. They discovered that this new state of matter behaves like a fluids. It is believed that up to a few milliseconds after the big bang the universe was in a quark –gluon plasma state. The properties of this quark –gluon plasma state and high energy nuclear physics experiment are currently investigated at the Brookhaven National Laboratory’s Relativistic Heavy –Ion Collider (RHIC) and in CERN’s Large Hadrons Collider (LHC). Thus the study of charged particles and fluids interacting with self –consistent electric and magnetic field is plasma physics. It is basic research discipline that has many different areas of application – space and astrophysics, controlled fusion, accelerator or particle physics and beam storage.