Plasma technology in South Africa

By Jaco van der Walt, South African Nuclear Energy Corporation (Necsa)

 

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Published in:

Energy Efficiency Made Simple Vol III: Energy and enviroFiciency November 2012 - Chapter 5: pages 68 - 69

Enquiries: mail jaco.vanderwalt@necsa.co.za

 

The most simplistic definition of a plasma is that it is a gas which conducts electricity. At normal temperatures and pressures gases are usually very good electrical insulators. This is because the electrons are tightly bound to the gas atoms or molecules and are not free to move in response to an externally applied electric or magnetic field. Under certain conditions, the electrons can be removed from their parent atoms or molecules by the process of ionisation. This can be achieved by passing an electrical current through the gas or heating the gas to a high temperature. The gas will then consist of negatively charged electrons and positively charged ions, which are free to move with respect to one another, forming a plasma which conducts electricity. Since electrons and ions are produced in pairs, most of the plasma remains neutral. A plasma can also be formed by applying a high electric field to ionise the gas.

 

Take note

  • The introduction of electricity facilitated industrial applications of manmade plasmas, such as arc welding and metallurgical furnaces.
  • The biggest application of plasmas is in the metallurgical and waste destruction industries.
  • Plasma technology can play an important role in meeting growing energy demands as well as in cleaning up the country’s waste.