346
15.
COSMIC RAYS
_
K.
This recharging is indicated at aaa in gure 15—5.
The
increasing rapidity of discharge of the electrometer as the apparatus is carried to higher and higher elevations is shown in this gure
_
”by the increasing slopes of the lines between each recharge.
_
Thus, the increasing strength of the cosmic rays With altitude may
be measured.
'
Occasionally, as at 5 in gure '15—5, a sudden loss of charge
occurs.
This abrupt ionization of the gas in the chamber is
referred to as a cosmic ray bursz‘.
These bursts occur more fre—
'
quently at the higher altitudes.
'
Another form of apparatus is shown in gure 15—6. The ionization current passes through a high resistance R and produces an
e.m.f. between its ends, which
_
A/
_
is amplied and then record%%Â
ed on the
%
°—C—
Upon cahbratmg the elec—
/////////
@
trometer
or
the ampl1fymg
'
llll\l
equipment, it is possible to"
:
_
calculate the number of ions
FIG. 15—6.
Alternative form of recording formed each second. When a1_
apparatus‘
lowance has been made for
the rate of
_
recombination
the ions with each other, it is found
that there are approximately two ion pairs produced at sea level in
each cubic centimeter of air at standard pressure (760 millimeters)
and temperature (0° C.) each second by cosmic rays received at a
magnetic latitude of 50°. At the same latitude, but at an eleva—
,
'
.
tion of 19,000 meters (11.7 miles), the strength of the rays is
,
.
found to be 170 times this value.
'
1544.
The Constancy of the Average Intensity of Cosmic
Rays.——To the cosmic ray meter of gure 15—4, there is added &
radioactive substance whose radiations produce a steady elec—‘_
trometer current in the opposite direction to that produced by the
cosmic rays.
The strength of the local ionization is adjusted
_
'
until it is equal to theaverage intensity of the cosmic raye. The
-
electrometer deections will then show any change in the intensity
—
of the cosmic rays fr'omtheir average value. It is found that the
,
'
_
’rays are of nearly constant value but that som—e variations do occur.
'
to :a close approximation, that the intensity is
‘
inVersely proportional to the bardmetric pressure.
'
15.
COSMIC RAYS
_
K.
This recharging is indicated at aaa in gure 15—5.
The
increasing rapidity of discharge of the electrometer as the apparatus is carried to higher and higher elevations is shown in this gure
_
”by the increasing slopes of the lines between each recharge.
_
Thus, the increasing strength of the cosmic rays With altitude may
be measured.
'
Occasionally, as at 5 in gure '15—5, a sudden loss of charge
occurs.
This abrupt ionization of the gas in the chamber is
referred to as a cosmic ray bursz‘.
These bursts occur more fre—
'
quently at the higher altitudes.
'
Another form of apparatus is shown in gure 15—6. The ionization current passes through a high resistance R and produces an
e.m.f. between its ends, which
_
A/
_
is amplied and then record%%Â
ed on the
%
°—C—
Upon cahbratmg the elec—
/////////
@
trometer
or
the ampl1fymg
'
llll\l
equipment, it is possible to"
:
_
calculate the number of ions
FIG. 15—6.
Alternative form of recording formed each second. When a1_
apparatus‘
lowance has been made for
the rate of
_
recombination
the ions with each other, it is found
that there are approximately two ion pairs produced at sea level in
each cubic centimeter of air at standard pressure (760 millimeters)
and temperature (0° C.) each second by cosmic rays received at a
magnetic latitude of 50°. At the same latitude, but at an eleva—
,
'
.
tion of 19,000 meters (11.7 miles), the strength of the rays is
,
.
found to be 170 times this value.
'
1544.
The Constancy of the Average Intensity of Cosmic
Rays.——To the cosmic ray meter of gure 15—4, there is added &
radioactive substance whose radiations produce a steady elec—‘_
trometer current in the opposite direction to that produced by the
cosmic rays.
The strength of the local ionization is adjusted
_
'
until it is equal to theaverage intensity of the cosmic raye. The
-
electrometer deections will then show any change in the intensity
—
of the cosmic rays fr'omtheir average value. It is found that the
,
'
_
’rays are of nearly constant value but that som—e variations do occur.
'
to :a close approximation, that the intensity is
‘
inVersely proportional to the bardmetric pressure.
'