Cherenkov Radiation
By: Thomas Lee Abshier, ND
Mass travels at less than the speed of light though space, but Cherenkov Radiation
on its surface appears to violate this rule. We will see that this apparent violation
actually conforms to the conventional rules governing kinetic energy and the processes
by which mass transits through space.
When a charged particle is generated with a high kinetic energy from a nuclear decay,
from a particle accelerator, or by particle decay, it may have a relativistic speed
in vacuum space. This means that its speed is very close to the vacuum speed of
light, and that it begins to show relativistic effects such as mass accumulation,
etc. When these high-energy charged particles transit through optically transparent,
refractive, dielectric materials, such as water, glass, diamond, etc, they interact
with the atoms bonded to the crystal lattice or molecules. As these relativistic
charged particles interact with the atoms in the media, there are a number of modes
by which the energy may eventually be released including Bremsstrahlung, transition
radiation, thermal motion, ionization, and Cherenkov radiation. In fact, the amount
of energy lost to Cherenkov radiation is small, composing only about 1/5000th of
the total energy lost. The energy is lost very quickly, in about 10-10 sec.
Cherenkov radiation is the energy radiation mode we shall consider in this section.
The relativistic charged particle stresses (and deforms) the atomic bonds between
atoms composing the lattice of a solid, or the intra-molecular atomic bonds. The
release of the compression or tension of these bonds produces photons covering a
broad frequency range. And, the photon energy loss per unit of wavelength is proportional
to the cube of the frequency, thus higher frequencies are more common and the light
appears to be a bluish white.
Since the particle is traveling faster than the rate that light propagates in the
media, the photons travel outward in a cone-shaped distribution along the locus of
the particle. The angle of the cone is dependent upon the velocity of the particle,
and can be used to assess the particle’s velocity. The smallest angle of the cone
of light travels in a cone-shaped distribution. This cascade of photons is called
Cherenkov Radiation.
This radiation is generated when near vacuum-speed-of-light charged particles pass
through a dipolar media. The polar field of the transiting charge causes a stress,
and hence movement, in the molecular and atomic spacing of the dipolar media. After
the transiting charge leaves each increment of space, the energy of displacement
and stress produced by the high velocity particle is released by the formation of
photons. The light frequencies emitted in this energy release are continuous across
the UV through Infrared spectrum. The intensity of each frequency photon is proportional
to the cube of its frequency, meaning that higher frequency photons will strongly
dominate the spectrum of emission. Thus, Cherenkov radiation emissions will have
their highest output in the ultraviolet region, with violet light having a lower
intensity, Blue still lower, red still lower, and infrared even lower. And, since
the sensitivity of the eye peaks at the “green” frequencies of light, the human perceptual
experience is a blue white light being radiated from the dielectric medium.
Photons traveling through the refractive medium travel at a slower speed than a near-light-speed
particle because photons are absorbed and re-emitted at each moment as they transit
through this atomic and molecular dipole space, resulting in a time-delay at each
increment of distance transited by each photon. This variation in local speed of
light is quantified in Snell’s law, which gives each transparent material an index
of refraction based on the ratio between the speed of light in a vacuum, and the
speed of light through the material. Diamond has a relatively high index of refraction,
around 2.4, compared to air, which is close to the index1.0.
A relativistic charged particle traveling close to the vacuum speed of light, entering
a water medium, such as is seen in a swimming pool reactor, will produce the characteristic
ghostly blue-white light of Cherenkov radiation. These high-energy particles are
traveling faster than light can travel in that medium, so the photons generated radiate
out from the particle’s track in a cone-like pattern. These high-energy charged
particles generate photons by electrically stressing the medium, and thus transmitting
kinetic energy to the medium particles.
The result is a bow-shock, in phase, photon distribution around the particle’s path.
This phenomenon is similar to the bow-shock created by a boat passing through water,
where the speed of the boat is faster than the speed at which a ripple can proceed
from the boat. The effect is likewise similar to the supersonic aircraft, traveling
through the air at a speed which exceeds the rate at which sound can carry its compression
away from the plane.
Neutral particles such as neutrons do not create Cherenkov radiation. Which means
that their presence passing through a Dipolar medium (i.e. negative electron cloud
and positive nucleus) does not disturb the relative placement between these two regions
of charged particles. Photons and charged particles, on the other hand, do produce
a dipolar displacement. The difference in neutral particle and charged particle
response provides strong evidence that the speed of light through a refractive medium
is not based on a Dipole Sea mediated and .
Rather, the effective and of the light-conducting medium is the result of the photon’s
absorption and reemission by the atoms and molecules of the dipolar refractive medium.
Thus, the absorption and reemission of photons may on a deeper level be mediated
by a compression and relaxation of the interatomic atomic bonds within molecules
and within a solid crystalline lattice. Such effects would require the displacement
of atoms in relationship to each other, with the associated capacitive static charge-polarization
effects, and inductive charge-movement effects.
This collage of experimental evidence around neutral particle effects, charged particle
effects, and photon effects provides strong proof that the inductive and capacitive
effects associated with the absorption and release of that energy in the refractive
medium generates the effective photonic rate of transit through these materials.
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/einvel.html
http://en.wikipedia.org/wiki/Cherenkov_radiation
The relativistic charged mass transiting a transparent dipolar refractive medium
loses energy and velocity through a number of collision-related mechanisms. In effect,
kinetic energy is transferred from the moving particle to the atoms of molecules
or crystalline lattice by displacing the atoms, which in turn radiate energy as photons,
or retain that energy as velocity. The force interaction between the two entities
(moving particle and stationary atom) is a repulsion or attraction, which gives the
atoms a velocity, and hence deform the original bond-length of the undisturbed equilibrium.
In the case of a high velocity electron moving through water, the presence of the
electron’s charge and movement-based field allows the electron to exerts a forward-directed
force against the electron clouds of the atoms of the water molecules. The overwhelming
force of the particle’s inertia allows the charged particle to move through the water,
but only at the expense of multiple collisions, and a short track prior to depletion
and absorption into the water molecules. Thus, other than Bremsstrahlung radiation
directly from the decelerating electron, the rest of the kinetic energy of the electron
will be lost by the conversion of into the kinetic energy of the electrons, atoms
and molecules of the water, which in turn will produce ionization, transition radiation,
or Cherenkov radiation. All these forms of energy loss are conversions of the kinetic
energy field of the incoming particle into other forms of energy, either kinetic
or photonic.
Depending on the material, the intensity of the Cherenkov radiation produced may
be small or large compared to the energy lost by ionization, Bremsstrahlung, and
orbital transition radiation. Ionization occurs when sufficient kinetic energy is
imparted to the electron to remove it from the atomic orbital system. Bremsstrahlung
is a German word meaning “braking radiation”, and is formed when energy is lost to
the local space as the incoming high-energy particle slows upon approaching an atom
or molecule in the target medium. A portion of the kinetic energy field disconnects
from the incoming high-energy particle, and forms into a photon now that it is no
longer connected to a mass.
And, orbital transition radiation is the radiation produced by the quantum drops
in energy as excited electrons drop back to lower energy states. When the electron
drops into the lower energy orbital, it likewise leaves a quantum of kinetic energy
field in the space, disconnected from a mass, and thus organizes into a photon.
Cherenkov radiation is produced by the energy release as interatomic bond lengths
drop back into equilibrium distance within a molecule or in a crystalline or amorphous
lattice after being deformed by the incoming particle. The incoming, high velocity,
charged particle repels and attracts atoms bound in molecules and lattice structures
thus causing an increase or decrease in bond length, corresponding to potential energy
stored in the tension or compression of the bond. The tension of the “spring” can
be released as kinetic energy, which will then be met by bond forces resisting its
continued motion. If the amount of energy applied is small, the lattice or molecule
may be able to retain this energy as thermal motion in the medium. But, if the displacement/deformation
potential energy is high, the sharp deceleration of the atoms as they collide with
their bonded pairs results in the dissociation of the kinetic energy field from the
moving atom, thus precipitating the generation of a photon.
Wavelength (m) Frequency (Hz) Energy (J)
Radio > 1 x 10-1 < 3 x 109 < 2 x 10-24
Microwave 1 x 10-3 - 1 x 10-1 3 x 109 - 3 x 1011 2 x 10-24 - 2 x 10-22
Infrared 7 x 10-7 - 1 x 10-3 3 x 1011 - 4 x 1014 2 x 10-22 - 3 x 10-19
Optical 4 x 10-7 - 7 x 10-7 4 x 1014 - 7.5 x 1014 3 x 10-19 - 5 x 10-19
UV 1 x 10-8 - 4 x 10-7 7.5 x 1014 - 3 x 1016 5 x 10-19 - 2 x 10-17
-X-ray 1 x 10-11 - 1 x 10-8 3 x 1016 - 3 x 1019 2 x 10-17 - 2 x 10-14
Gamma-ray < 1 x 10-11 > 3 x 1019 > 2 x 10-14
http://imagine.gsfc.nasa.gov/docs/science/know_l1/spectrum_chart.html
In terms of electron volts, 1 joule = 6.24150974 × 1018 electron volts
Infrared = .001248 ev - 1.87 ev
Visible Light = 1.87 ev -3.12 ev
Ultraviolet = 3.12
ev – 124.8 ev
X Ray = 124.8 ev – 124,800 ev
The bond strength of the O-H Bond in water is 110 Kcals:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/B/BondEnergy.html
Convert O-H Bond strength in Kcals to Electron Volts
1 Kilocalorie = 4184.00 joules
1 mole = 6.02214x1023 bonds
[110kcals/mole x 4184joules/kcal
x 6.24 x 1018 ev/joule x 1/(6.02214x1023 bonds/mole)]
= .0477 ev
C-C bond: 80.5 kcals/mole
C=C bond: 145 kcals/mole
C≡C bond: 198 kcals/mole
C-H bond:
98.2
C-Cl bond: 78
C-O bond: 79
C=O bond: 173
C-Br bond: 54
O-O bond: 34
O-H bond: 109.4
H-H
bond: 103.2
N-N bond: 37
N-H bond: 98.2
H-Cl bond: 102.1
H-Br bond: 86.7
Cl-Cl bond: 57.1
Br-Br
bond: 46
Biophysical Ecology by David Murray Gates pg86
http://books.google.com/books?id=Lx1BclFf7QIC&pg=PA85&lpg=PA85&dq=bond+ energy+electron+volt&source=web&ots=19YkOfRbki&sig=rSGGQGp9F65SdHempc Kptwenq4M&hl=en#PPA91,M1
95.06 Kcals = 2.48 eV
120 Kcals = 237.5 nm photon
O-H bond of water being 109.4 kcals =109.4 kcals x 2.48 eV / (95.06 Kcals) = 2.85
eV which is in the visible light spectrum. Thus, while 2.85 eV is the minimum energy
for breaking the O-H bond, this is not the only energy that will be able to interact
with the atoms of the watery molecular milieu. Each atom and molecule can be accelerated
by the collision with the incoming relativistic particle. In turn, those particles
will collide with other particles, causing them to decelerate and accelerate other
atoms. The result will be the breaking and remaking of bonds, and in general the
creation of a high temperature outward spreading cone of activated atoms, electrons,
molecules, and photons, each one colliding, decelerating and activating all modes
of motion. The important point being that this large number of activated atoms,
each transmits their kinetic energy as they collide, and some will radiate a portion
of it as they rapidly decelerate upon collision. Thus, it is plausible that an incoming
electron, with millions of electron volts of energy, could generate the experimentally
observed broad spectrum of photons, each in the spectrum of 1-100 electron volts,
with the high energy photons predominating.
This conversion from kinetic energy to photon as a result of atomic or electron collision
and deceleration is thus a likely, or at least possible, mechanism for the observed
photonic Cherenkov radiation. The inelastic collision, rapid deceleration, and incomplete
transfer or retention of kinetic energy is at the base of this energetic transfer.
When symbolically illustrating energy transfer upon collision between atoms, the
Feynman diagram of energy transfer is employed. In this representational system,
the photon is considered to be the vehicle of force transfer, as well as the byproduct
of incomplete transfer. And, while both the nomenclature and concept are generally
accurate, the “photon” that transmits the force of collision is actually a kinetic
energy field, and the Force Particles being emitted by each electron engaged in the
collision. By examining the underlying field interactions associated with the collision
we can represent the particulate interaction and movement in a more complete and
mechanistic manner.
In the case of thermal collisions (i.e. at energies much less that 1 eV), the average
energy gained and lost is constant in a isolated system at thermal equilibrium. But,
in an open system, energy is lost at the edges of the system, such as in a closed
glass container filled with ice and water sitting in a laboratory.
When thermal atoms collide with each other, in a gas, liquid or solid, they can strike
at any angle from direct, to glancing. The angle and directness of collision determines
the amount of energy transferred from one to the next, and the rate of deceleration
and acceleration of the next determines whether a full energetic transfer occurs,
or if there is a component of radiation generated and leaked as a result of the mismatched
collision.
As the incoming atoms come closer, their outermost charges will interact and repel
because of the mutually negative outer electron orbital shells. The result will
be that the incoming particle will decelerate because of the force opposing its kinetic
energy, momentum, and inertia. The result will be that the kinetic energy field
associated with the incoming particle will transit to the target atom, and in a complex
dance, energy will be transferred from the one atom to the next.
In the high energy collision between the relativistic charged particle and the dielectric
refractive medium, the incoming particle repels or attracts the target particles,
and thus imparts kinetic energy to the atoms in the lattice or molecules. The photons
generated from these high energy collisions create Cherenkov radiation in a collision
melee that also creates Bremsstrahlung radiation, transition radiation, and ionization.
When the incoming particles strike a direct or glancing blow to an atom bonded to
a molecule or lattice, and those atoms strike other atoms, the incompletely transferred
kinetic energy is lost to space as a photon. The target atoms in the refractive
media provide a larger inertial resistance than their mass since they are bonded
to molecules or lattice. This bulk structure also provides repulsion that brakes
the velocity of the incoming charged particles and causes less kinetic energy to
be transmitted in the collision.
The kinetic energy of the incoming particle is thus either transmitted as kinetic
energy and stored potential energy in compressed bonds, or it is lost as radiation
in the process of deceleration. And, this broad spectrum high energy thermal type
radiation is the basis for the Cherenkov radiation, which is only unique in the sense
that the incoming particle is moving so fast that the leading edge of the photons
generated by the kinetic energy release are radiating out from the track of the particle
in such a way as to create a bow shock pattern of outward radiating photons.
An expansion of this phenomenon of conversion from kinetic energy to photonic energy
follows. The incoming particle has a kinetic energy field, consisting of the collapsing
magnetic field generated in the trailing edge of the particle, which generates the
E field that propels the mass forward. The inertia of the target particle resists
the movement by the incoming particle. When the mass is equal, and the angle of
attack is 0 , the kinetic energy transfer is complete, passing fully from the incoming
to target mass without loss or delay, much like a direct-on billiard ball shot. But
when the mass/inertia of the incoming and target mass are mismatched, there will
be incomplete energy transfer. In the case of the comparatively massive target,
the incoming mass will reflect. The incoming energy is able to only transfer an
amount equal to the conservation of momentum. The component of velocity perpendicular
to the center of mass and surface will be reflected back, minus the amount of kinetic
energy corresponding to the conservation of momentum. Likewise a heavy incoming
and light target mass collision will result in only a partial kinetic energy transfer,
since the amount of momentum the target can absorb with the incoming velocity is
unable to create that level of kinetic energy.
