TABLES
469
TABLE 13.—ABSORPTION COEFFICIENTS ron GAMMA RAYS
_1
.
.
Emîtting
pu (cm. ) m alummum
,
,u (cm. _1)
Substance
in lead
I
II
III
IV
UÏË1
24.
0.7
.
2.3
UXg
..
'
0.14
0.72
‘
Io
1088
22.7
0.41
'
Ra
354
16.3
0.27
R&B
230
40
0.57
1.5
RaC+Ra C”
..
0.23; 0.12
0.53
'
Ra D
.
.
.
.
45
1.17
RaE
..
0.24
_
Po
2700
46
.
.
.
.
very feeble
-
0.96
_
RAC
25
0.29
AC B
120
31
0.45
ACC+ACC"
..
0.20
0.86
:MThZ
26
0.12
0.62
'
Th B
160
32
0. 36
-
ThC+ThC”
..
0.096
0.46
From Radiaaclivilâ, by Madame P. Curie, p. 305, published by Hermann & Co., Paris, 1935. '
.x
TABLE 14.——Somæ MASS ABSORPTION COEFFICIENTS FOR X—RAYS
‘
'
'
Wave—length in Angstroms
—
_
.
100
.
125
.
150
.
175
.200
.250
.300
Carbon..………………
.143
.150
.156
.163
.175
.186
.20.2
'
Aluminum.
.
.
.
.
.
.
.
.
..
.
157
.180
.204
.228
.270
.395
.550
Iron....……..………
.275
.400
.611
.85
1.10
2.10
3.â8
‘
Copper....….'.………
.340
.530
.810
1.12
1.59
2.97
4.
—_
È
.350
.400
.500
.600
.700
.300
.900
Carbon..….……Î
.224
.247
.316
_.425
5.(5Ë2 7.Ëg8 1â-24
Aluminum..……….…
.770
1.08
1.92
3.20
358
550
710
'
Iron........…………
5.20
7.50
14.2
23.7
49.2
71-5_
950
Copper...…….......
7.00
10.0
19.0
'
32.0
«.
-
_'
.
°
_
’
nd
Interpolated from Table I, pp. 801—802, A- H- C0mDt0n and
S' K“ Alhson, X rays m Theory a
_
Experiment, D. Van Nostrand Co. (1935).
'
.
_
\