thing.
This wae an older cyclotron,
It
happens to be -=- this is in no sense a refleotion on the cyclotron or its operators
but it 1s more or less typical,
This is a gmail cyclotron at the
Sloan Laboratory at Yale University and
right where the stone is in this picture,
the level wae of the order of 200 neutrons
per square centimeters per second, This
happens to be a sidewalk outside the cycloe
tron building,
This situation has also
since be rectified, °
May I have the next slide, please?
Thia photoctraph is not that of
some prehistoric monument.
It is thrown in
to represent the economic problem in the
shielding against fast neutrons originating
at a high energy, particularly a high energy
synchro-cyclotron site,
This is a shielding wall at the
University of Rochester and one should note
the massiveness of this type of shield,
An accurate survey must point out
the permissible neutron flux within a reacone
able value, otherwise one 1s going to go into