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Plasma Beams
They
are endowed with high gas as well as species temperatures, high
enthalpies, high densities of reactive species, electrical conductivities
and amenability to electromagnetic fields. Consequently both thermal
and non-thermal processing of new and designer materials can be
carried out with operational ease.Over the last two decades, low
temperature thermal and non-thermal plasmas have been finding
applications in key materials processing
and power generation sectors in strategic as well as
manufacturing industries. Plasma assisted waste treatment, benificiation
and decontamination, plasma surface modification, nano synthesis,
fusion applications,
plasma metallurgy, reentry simulators are some areas where significant
improvement in quality, specific yield and design of new products
have been seen.
On the ecology management sector one sees tremendous application
in municipal and bio-medical waste management,bulk water purification,
sterilization, automobile exhaust beneficiations etc.
The use of low-pressure
plasmas for materials processing has recently received
a great amount of interest. The promising applications of these
plasmas have been appearing in the fields of chemical processes
and semiconductor manufacturing. Applications include surface
deposition of all types of coatings such as : Hard /
Superhard Nanocomposites, Diamond and Diamond like Carbon (DLC)
coatings, etching of semiconductors, promotion of organic reactions,
etching of polymers to improve bonding of the other materials
etc.
Electron Beams
In
the second half of last century, High energy density electron
beams (HEDDB) started playing a vital role in processing and fabrication
of materials required for the then newly emergent technologies
like nuclear, space and defense industries.
Consequently, the technology of electron beams and their applications
to nuclear materials processing has been one of DAEs major
achievements during the last three decades.Currently, all the
electron beam empowered materials processing belong to two groups,
namely, thermal and non thermal. The thermal processing activities
like welding, melting and evaporation have been an essential integral
part of the high technology industries like nuclear , space, defense
and advanced manufacturing almost right from its inception. In
recent years, the advent of industrial electron accelerators have
opened up the field of non thermal radiation
processing where electron beams in the energy range
of 100 KeV to 10 MeV and average powers of 1 kW to 500 kW are
finding important applications in areas like plastics modification,
sterilization of medical products, exhaust gas purification, food
preservation, irradiation of wires and cables, etc.
Laser Beams
These
are highly monochromatic coherent source of light energy that
can be focused to a very small spot. It can also be controlled
in time ranging from a few femto-second to continuous wave mode.
These characteristics combined with very high power capability
of lasers have made the laser a tool of unprecedented precision
and power.High power lasers are being used world wide in many
industries to process a large variety of materials in different
ways. For examples, in diamond industry
lasers are used to cut and drill holes in diamond,
in automobile industry they are used to cut, weld and heat-treat
different parts and components, in nuclear industry they are finding
application in cutting (remote and under water) as well as welding
of radioactive materials, concrete scabbing, removing
paints from radioactive surface, cutting of concrete and other
structural materials for decontamination/ decommissioning application.
The two lasers which are most popular for these applications are
the high power CO2 laser and the Nd:YAG solid state laser. The
CO2 laser is the real workhorse in industry for material processing
applications due to its high power capability, efficiency and
versatility, and relatively lower cost. For applications requiring
CW laser power in several kW range at present CO2 laser is the
only choice.
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