LJ POLYTECHNIC PROJECTS/MODELS 2015
Fusion Power Production
Nuclear fusion is the source of energy in stars such as the sun. The best fuels for fusion are two types, or isotopes, of hydrogen - deuterium and tritium. Energy is released as atomic nuclei are forced together at high temperatures and pressures to form larger nuclei. Reproducing these conditions on Earth is extremely challenging
Inertial electrostatic confinement nuclear fusion reactors are actually not very complicated in the way that they work, albeit the difficulty involved in building one that does work. Basically, a fusor consists of two concentric, usually spherical grids inside a vacuum chamber, the inner one usually about 5 times smaller in diameter than the outer, (most fusors use the vacuum chamber itself as an outer grid). A vacuum of about 1 millitorr (the exact pressure varies from fusor to fusor) is pulled on the vacuum chamber, and then it is backfilled with deuterium to a pressure of about 5 millitorr or less. The inner grid is then charged with anywhere from -20,000 to -100,000 volts at a current of at least 2 mA, the outer grid is left grounded. Due to a process called electrostatic field emission (from the inner grid), the deuterium is ionized. Some ions strike the wires, and others carry on through the grid. Some of the ions that pass through the grid collide, and some of those collisions result in the fusion of the deuterium ions into helium
Current R&D activities on materials for fusion power reactors are mainly focused on plasma facing, structural and tritium breeding materials for plasma facing (first wall, divertor) and breeding blanket components. Most of these activities are being performed in Europe, Japan, the People's Republic of China, Russia and the USA. They relate to the development of new high temperature, radiation resistant materials, the development of coatings that will act as erosion, corrosion, permeation and/or electrical/MHD barriers, characterization of candidate materials in terms of mechanical and physical properties, assessment of irradiation effects, compatibility experiments, development of reliable joints, and development and/or validation of design rules. Priorities defined worldwide in the field of materials for fusion power reactors are summarized, as well as the main achievements obtained during the last few years and the near-term perspectives in the different investigation areas.
Shah Chandresh , Shyamsukha Ronak