Apparatus:
TEL-Atomic
lecture
hall
cloud
chamber,
~
500
mL
ethanol,
dry
ice,
300W
light
source.
Description:
This
can
be
used
to
show
examples
of
cosmic
radiation,
radiation
of
radioactive
sources,
decrease
with
time
of
the
alpha
rays
of
thorium-emanation-containing
air.
There
are
characteristic
patterns
left
by
the
different
particles
in
the
cloud
chamber.
Alpha
particles
leave
short
and
strong
straight
paths,
beta
particles
leave
weak
but
straight
paths,
and
gamma
radiation
leaves
weak,
crooked
paths
resultant
from
secondary
electrons
released
from
air
molecules.
This
demonstration
should
be
set
up
10
-
15
minutes
beforehand,
as
the
effects
will
not
be
visible
for
this
length
of
time.
In
warm
or
moist
rooms,
protect
the
observation
window
from
misting
by
applying
anti-fog
compound.
This demonstration requires 2 days notice.
PIRA 7D30.60