276
12.
ALPHA, BETA AND GAMMA RAYS
Hev.
The relativity mass equation (2—25) must be used. Then,
2
43%
Hr =
@
=
@
(1
—
%> ,
(12—14)
e
e
c
where H is the strength of the magnetic eld in oersteds,
is
the rest mass and 5 is the charge of a particle of velocity v centimeteré per second, and 6 is the velocity of light. The velocity of
the beta particles may be determined by solving equation 12—14
for 7).
The number of beta particles emitted each second in the continudus spectrum can be determined by substituting a Faraday
chamber and electrometer for the photographic plate of gure
_
12—12.
The number of atoms which disintegrate each second
.
_
may
be
calculated from the
%
transformation constant (X) and
Ë
the total number of atoms in" the
â
source.
It is found that the
%
number of beta particles which
œ
.
appear is the same'as the numë
ber of atoms which are trans—
Ê
'
formed into new and diHerent
°'2
°'4
°'6
°'8
"0
1.z
atoms._ It is thus established ‘
ENERGY … M.€.V.
that thesedisz‘nægmtion electrons
'
FIG' l2."14' Energy
diStribution ?mong
come from the nucleus and not
the dismtegration electrons of rad1um E.
«
fromthe outer parts
of the atom.
Their distribution of energy, as illustrated in gure 12—14 for
the case
6 of radium E, is in strong contrast to the ne structure
,
distribution observed in the case of alpha particles. The alpha
particles which leave a disintegfating nucleus are conned to denite energies, whereas
beta particles from the nucleus are continuously distributed over a wide range of energies. A satisfactory ' '
explanation of the beta ray energy distribution "has not yet
been
offered although several theories have been proposed. In one of
.
these, it is assuméd thatwhen a beta particle is emi'tted, ahewparticle
whose charge is zero and whose mass is very small.“
'
'
'
Pauli_hàs called this hypothetical particle a neutrino.
_
'
The maximum energy of the electrons
ejected _
\
—
from/a radioactive nucleus is a characteristic of the
_
'
substance. The more accurately determined values, in
12.
ALPHA, BETA AND GAMMA RAYS
Hev.
The relativity mass equation (2—25) must be used. Then,
2
43%
Hr =
@
=
@
(1
—
%> ,
(12—14)
e
e
c
where H is the strength of the magnetic eld in oersteds,
is
the rest mass and 5 is the charge of a particle of velocity v centimeteré per second, and 6 is the velocity of light. The velocity of
the beta particles may be determined by solving equation 12—14
for 7).
The number of beta particles emitted each second in the continudus spectrum can be determined by substituting a Faraday
chamber and electrometer for the photographic plate of gure
_
12—12.
The number of atoms which disintegrate each second
.
_
may
be
calculated from the
%
transformation constant (X) and
Ë
the total number of atoms in" the
â
source.
It is found that the
%
number of beta particles which
œ
.
appear is the same'as the numë
ber of atoms which are trans—
Ê
'
formed into new and diHerent
°'2
°'4
°'6
°'8
"0
1.z
atoms._ It is thus established ‘
ENERGY … M.€.V.
that thesedisz‘nægmtion electrons
'
FIG' l2."14' Energy
diStribution ?mong
come from the nucleus and not
the dismtegration electrons of rad1um E.
«
fromthe outer parts
of the atom.
Their distribution of energy, as illustrated in gure 12—14 for
the case
6 of radium E, is in strong contrast to the ne structure
,
distribution observed in the case of alpha particles. The alpha
particles which leave a disintegfating nucleus are conned to denite energies, whereas
beta particles from the nucleus are continuously distributed over a wide range of energies. A satisfactory ' '
explanation of the beta ray energy distribution "has not yet
been
offered although several theories have been proposed. In one of
.
these, it is assuméd thatwhen a beta particle is emi'tted, ahewparticle
whose charge is zero and whose mass is very small.“
'
'
'
Pauli_hàs called this hypothetical particle a neutrino.
_
'
The maximum energy of the electrons
ejected _
\
—
from/a radioactive nucleus is a characteristic of the
_
'
substance. The more accurately determined values, in