I believe photons are pure energy...no mass...once fusion has occured on the surface of the sun or stars the mass is converted to pure energy and then travells in the form of photon...
ways to control fusion fuel:
Gravitational
One force capable of confining the fuel well enough to satisfy the
Lawson criterion is gravity. The mass needed, however, is so great that gravitational confinement is only found in
stars (the smallest of which are
brown dwarfs). Even if the more reactive fuel deuterium were used, a mass greater than that of the planet
Jupiter would be needed.
Magnetic
See Magnetic fusion energy for more information. Since
plasmas are very good electrical conductors,
magnetic fields can also confine fusion fuel. A variety of magnetic configurations can be used, the most basic distinction being between
mirror confinement and toroidal confinement, especially
tokamaks and
stellarators.
Inertial
See Inertial fusion energy for more information. A third confinement principle is to apply a rapid pulse of energy to a large part of the surface of a pellet of fusion fuel, causing it to simultaneously "implode" and heat to very high pressure and temperature. If the fuel is dense enough and hot enough, the fusion reaction rate will be high enough to burn a significant fraction of the fuel before it has dissipated. To achieve these extreme conditions, the initially cold fuel must be explosively compressed. Inertial confinement is used in the
hydrogen bomb, where the driver is
x-rays created by a fission bomb. Inertial confinement is also attempted in "controlled" nuclear fusion, where the driver is a
laser,
ion, or
electron beam, or a
Z-pinch.
Some other confinement principles have been investigated, such as
muon-catalyzed fusion, the
Farnsworth-Hirsch fusor (
inertial electrostatic confinement), and
bubble fusion.
Nuclear fusion - Wikipedia, the free encyclopedia