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8 Ionizing Radiation and Life
Mr. Alexander Litvinenko, a former Russian dissident died on the 23rd of
November 2006 from purposeful polonium poisoning. In 1956 Irène Joliot-Curie,
whose parents first isolated polonium, died from leukemia, attributed to chronic
poisoning following the bursting of a capsule containing polonium 10 years earlier.
Polonium-210 is produced by irradiating natural Bismuth-209 with neutrons in a
nuclear reactor. The result is Bismuth-210, which beta decays into Polonium-210
with a half-live of 5 days. Polonium-210 is also present in cigarettes, being a
daughter isotope of the decay of uranium in the soil. Polonium-210 may account
for a large fraction of all smoking related lung cancers. When Polonium-210 is
combined with Beryllium, it creates neutrons though the reaction 9 Be + α →
12 C + n. The alpha particles from micrograms of Polonium reduce static charge
buildup on insulators. Polonium is even used in spacecraft for the heat it produces.
8.13 Mechanisms for Energy Loss by Light and Fast Moving
Particles
8.13.1 Radiation Tracks and Trails
The Apollo astronauts reported seeing a flash of light every few minutes. By
studying the tracks left in their plastic helmets, the flashes correlated with cosmic
ray particles, and were likely produced by Cherenkov radiation within the eye.
The mechanism for the production of cosmic ray tracks can be understood by the
electric interaction of energetic charged particles as they pass through substances,
and by the action of gamma rays in producing such energetic charged particles.
As ordinary matter is made up of charged particles, an ionizing stream of particles
passing through that matter will have a likelihood of inelastically colliding with
stationary charges. This collision can deflect the incoming particle and kick one of
the material’s particles into motion, as well as produce secondary radiation and even
create matter-antimatter pairs, also moving away from the scattering event. With
sufficient incoming energy, a cascade effect occurs, with each of the secondaries
engaged in their own sequence of scattering events. Side branches of a track are
called ‘spurs’, often produced by secondary scattered electrons (called ‘deltas’,
named to follow the sequence α, β, γ introduced by Rutherford for radioactive
particles).
If the material is a solid, a series of tracks may be formed with atoms no longer
occupying their original positions. The tracks, being of a different character than the
surrounding unaffected material, can often be etched out to make them more visible.
In a supercooled gas, the charges in the tracks may induce condensation, making a
vapor trail. In a superheated liquid, the track maybe visible by induced gas bubbles.
In water, an ionizing beam of particles will make a trail of hydroxyl radicals
(OH ).
8 Ionizing Radiation and Life
Mr. Alexander Litvinenko, a former Russian dissident died on the 23rd of
November 2006 from purposeful polonium poisoning. In 1956 Irène Joliot-Curie,
whose parents first isolated polonium, died from leukemia, attributed to chronic
poisoning following the bursting of a capsule containing polonium 10 years earlier.
Polonium-210 is produced by irradiating natural Bismuth-209 with neutrons in a
nuclear reactor. The result is Bismuth-210, which beta decays into Polonium-210
with a half-live of 5 days. Polonium-210 is also present in cigarettes, being a
daughter isotope of the decay of uranium in the soil. Polonium-210 may account
for a large fraction of all smoking related lung cancers. When Polonium-210 is
combined with Beryllium, it creates neutrons though the reaction 9 Be + α →
12 C + n. The alpha particles from micrograms of Polonium reduce static charge
buildup on insulators. Polonium is even used in spacecraft for the heat it produces.
8.13 Mechanisms for Energy Loss by Light and Fast Moving
Particles
8.13.1 Radiation Tracks and Trails
The Apollo astronauts reported seeing a flash of light every few minutes. By
studying the tracks left in their plastic helmets, the flashes correlated with cosmic
ray particles, and were likely produced by Cherenkov radiation within the eye.
The mechanism for the production of cosmic ray tracks can be understood by the
electric interaction of energetic charged particles as they pass through substances,
and by the action of gamma rays in producing such energetic charged particles.
As ordinary matter is made up of charged particles, an ionizing stream of particles
passing through that matter will have a likelihood of inelastically colliding with
stationary charges. This collision can deflect the incoming particle and kick one of
the material’s particles into motion, as well as produce secondary radiation and even
create matter-antimatter pairs, also moving away from the scattering event. With
sufficient incoming energy, a cascade effect occurs, with each of the secondaries
engaged in their own sequence of scattering events. Side branches of a track are
called ‘spurs’, often produced by secondary scattered electrons (called ‘deltas’,
named to follow the sequence α, β, γ introduced by Rutherford for radioactive
particles).
If the material is a solid, a series of tracks may be formed with atoms no longer
occupying their original positions. The tracks, being of a different character than the
surrounding unaffected material, can often be etched out to make them more visible.
In a supercooled gas, the charges in the tracks may induce condensation, making a
vapor trail. In a superheated liquid, the track maybe visible by induced gas bubbles.
In water, an ionizing beam of particles will make a trail of hydroxyl radicals
(OH ).