Directed-energy weapon
Later in life, Tesla made some remarkable claims concerning a
"teleforce" weapon [31] The press called it a "peace ray" or death
ray. [32] [33] In total, the components and methods included
[34][35]:
An apparatus for producing manifestations of energy in free air
instead of in a high vacuum as in the past. This, according to
Tesla in 1934, was accomplished.
A mechanism for generating tremendous electrical force. This,
according to Tesla, was also accomplished.
A means of intensifying and amplifying the force developed by the
second mechanism.
A new method for producing a tremendous electrical repelling force.
This would be the projector, or gun, of the invention.
Tesla worked on plans for a directed-energy weapon between the
early 1900s till the time of his death. In 1937, Tesla composed a
treatise entitled "The Art of Projecting Concentrated
Non-dispersive Energy through the Natural Media" concerning charged
particle beams. [36] Tesla published the document in an attempt
expound on the technical description of a "superweapon that would
put an end to all war". This treatise of the particle beam is
currently in the Nikola Tesla Museum archive in Belgrade. It
described an open ended vacuum tube with a gas jet seal that
allowed particles to exit, a method of charging particles to
millions of volts, and a method of creating and directing
nondispersive particle streams (through electrostatic repulsion).
[37]
Records of his indicate that it was based on a narrow stream of
atomic clusters of liquid mercury or tungsten accelerated via high
voltage (by means akin to his magnifying transformer). Tesla gave
the following description concerning the particle gun's
operation:
[The nozzel would] "send concentrated beams of particles through
the free air, of such tremendous energy that they will bring down a
fleet of 10,000 enemy airplanes at a distance of 200 miles from a
defending nation's border and will cause armies to drop dead in
their tracks". [38]The weapon could be used against ground based
infantry or for antiaircraft purposes. [39] Tesla tried to interest
the US War Department in the device. [40] He also offered this
invention to European countries.[41] None of the governments
purchased a contract to build the device. He was unable to act on
his plans. [42]
from wikipedia abt nicola tesla's death ray. 
