Radioactive Decay Law (Part 2)
Bubble Chamber
Bubble chamber is one of the devices used for registration of charged particles
The principle of operation of the bubble chamber was based on the boiling of the
liquid along the path of the particle when the charged particle moves in the
superheated liquid. If in the Wilson chamber the moving charged particle produces
water droplets in the superheated vapor, then in the bubble chamber the charged
particle forms vapor bubbles in the superheated liquid. Propane or liquid hydrogen
is used as a liquid in the bubble chamber.
Working principle.
It is known that the boiling temperature of the liquid depends on the external
pressure. If the external pressure on the liquid is equal to or less than the pressure
of saturated steam, then at that temperature the liquid boils. So in order to boil the
liquid, it is necessary to reduce the external pressure. We move the piston down.
But boiling does not occur immediately after a decrease in pressure, the pure
liquid, if not “touching” it, is in an unsteady state for a certain time (a few
seconds). This kind of liquid is called superheated. During the movement of a
charged particle within this liquid, ions are formed on its trajectory. Bubbles form
around the ions and boiling begins.
, Atomic structure
Rutherford’s experiments on α – particle scattering.
α - particles irradiated from a radioactive source fall on a thin foil made of gold.
The scattering particles fell on the screen, which was covered with a special
substance - sulfide zinc. As a result of the impact, small flashes appeared on the
screen – sparks. They observed these sparks through a microscope. It turned out
that most α-particles do not incline in any direction, passing through thin metal.
Few of the particles tend to practical angles, and in rare cases, some particles turn
180° and go back. Rutherford assumed that the atom was almost empty, its mass
and positive charge occupying a very small volume in the center of the atom.
Rutherford determined that -
1. if the α-particle passes at a distance from the nucleus,
then its trajectory is noticeably does not change.
2. if the α-particle passes near the nucleus, then the α-
particle changes the direction of its movement by 30º-
40º.
3. if the α-particle collides centrally with the nucleus,
then the α-particle changes its direction of motion to the
opposite.
Bubble Chamber
Bubble chamber is one of the devices used for registration of charged particles
The principle of operation of the bubble chamber was based on the boiling of the
liquid along the path of the particle when the charged particle moves in the
superheated liquid. If in the Wilson chamber the moving charged particle produces
water droplets in the superheated vapor, then in the bubble chamber the charged
particle forms vapor bubbles in the superheated liquid. Propane or liquid hydrogen
is used as a liquid in the bubble chamber.
Working principle.
It is known that the boiling temperature of the liquid depends on the external
pressure. If the external pressure on the liquid is equal to or less than the pressure
of saturated steam, then at that temperature the liquid boils. So in order to boil the
liquid, it is necessary to reduce the external pressure. We move the piston down.
But boiling does not occur immediately after a decrease in pressure, the pure
liquid, if not “touching” it, is in an unsteady state for a certain time (a few
seconds). This kind of liquid is called superheated. During the movement of a
charged particle within this liquid, ions are formed on its trajectory. Bubbles form
around the ions and boiling begins.
, Atomic structure
Rutherford’s experiments on α – particle scattering.
α - particles irradiated from a radioactive source fall on a thin foil made of gold.
The scattering particles fell on the screen, which was covered with a special
substance - sulfide zinc. As a result of the impact, small flashes appeared on the
screen – sparks. They observed these sparks through a microscope. It turned out
that most α-particles do not incline in any direction, passing through thin metal.
Few of the particles tend to practical angles, and in rare cases, some particles turn
180° and go back. Rutherford assumed that the atom was almost empty, its mass
and positive charge occupying a very small volume in the center of the atom.
Rutherford determined that -
1. if the α-particle passes at a distance from the nucleus,
then its trajectory is noticeably does not change.
2. if the α-particle passes near the nucleus, then the α-
particle changes the direction of its movement by 30º-
40º.
3. if the α-particle collides centrally with the nucleus,
then the α-particle changes its direction of motion to the
opposite.
