TABLES
463
_
TABLE 5.—RANGE or ALPHA PARTICLES IN VARIOUS SUBSTANCES
'
Extrapolated range = r. Gases
76 centimeters press‘ure, 15° C. Solids and
liqu1ds at 15° C.
'
Values from Radioactivité, by Madame P. Curie, pages 218—220 (1935).
|
r, cm.
r, crn,
‘
r, microns 73 microns
Air......…..…
3.87
6.96
Watef…….……
32.0
60.0
‘
3.64
6.60
Alcohol.………
70.5
Nitrogen..…….
3.89
7.0
Ether..…….…
43.0
’
Hydrogen.
17.3
32.5
Benzene..….…
36.3
70.0
ï
Helium.
.
.
.
.
.
.
.
.
21.5
39.0
Photo—gelatin. . N27
N52
_
Argon...…….…
4.17
7.3
For al ha
articles whose ran (: is 6.96 cm. in _air at 76 cm. 15° C.
-
'
P
P
g
,
r, microns
73 microns
Lithium..…………………
129.1
Tm
29.4 ‘
«
,_
Magnesium..….…………
57.8
Platinum..……………_…
12.8
Aluminum..………………
40.6
Gold..……………..……
14.0
‘
78.8
Lead..…...…….………
24.1
_
Iron..…...….…….……
18.7
Cadmium..…………….
24.2
Nickel..…….……………
18.4
Silver....……..…….…
19.2
,
-
Copper..……….…………
18.3
Zinc............-.......
22.8
—
-
‘
TABLE 6.—SÎOPPING POWER or VARIOUS SUÉSTANCES TO}; ALPHA PART;CL‘ES
Relative stopping power
.
Relative atomfc.st0pplng power
_
(air at 15° C. and
(relativeto äir
we1ghç 14.44 at 15 C.
and 76 cm.)
"
and 76 cm.)
‘_ _
'
»
'
‘
Air.
.
.
.
.
.
.
.
.
.
.
.
1.0
.
Air.ÿi
51-70'
,
Aluminum
.
.=
'
_
Hydrogen. _ _ _ __
0_21
Hydrogen..ç...r .
Copper23
_
‘
Helium.
.
..
.
.
..
.
0.17
'
035
" 3â
?
,
r
‘OXygen. . . .. .
.
1.07
Tm
'. "
,
"
Aluminum..……
’
‘-Î'
"
‘
_
,
2
,
ï WatervaP°f
15
carb°“
:
»
”
z‘\lcoholvaP0r40
,
,
x;
,
..
'z,‘1?}“ --byFRasetp48Pœm‘œH“
-'
_
-
,
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