CHAPTER 14
.
.
—
ARTIFICIAL TRAN SMUTATION
…
'
;
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14—1‘.
The First Articial Transmu‘cationQ—Thç small metal
bo>r
shown in the center of gure
contains a sample of
rad1um C’
.
Alpha particles whose rangeis 6.9 centimeters (air
_
equivalent) are
from the radioactive source
and pass through a small hole into the chamber Â. They traŸel
outward for a few centimeters but are allabsorbed by the gas in
the chamber long before reaching the thin foil Window C., Yet,
.
When certain gases are used, ashes of light can be seenvona the zinc
'
_
sulphide" screen B.
These
f
_
scintillations
are
obviously
_
À
produced by particles of un- "_' .. "
o("_—"Ÿ
*
usually long range.
With
‘Œ
hydrogen in thechamber, the
'
\\
particles were found to have
.
î,
C‘
»
'
a range
of 28 cent1meters (arr Fm. 14_1
equivalent). It 13 reasonable
&»Rùthepfdr‘d;Îf1-'9‘19.
.
tosuppose_that these particles
,
are protons (hydrogen nuolèiÿ:“fp‘rojeCtédf‘*fQijWä-ïd+'fbÿnïtherf'headf—0n,
elaStic collision “of
ThISIS $h0W_n—
to be true by deect1ngthelongœgpartldeswmhamagnetlc
eld (toget e/m)
Of Ç°nS€W_a*
tion of momentum“ and energyf0rîhlStYPËOÏCOHŒIOn ï The?ê
Speedlongrangepr0t°nsarecauedHParüdes
.
,
-
H particles
.
'
14—1zwheh
the
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1
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