ry
a
Ra
Fa
.
239.
L
{
er6n,
576 Mev
2287,
r
a
=
5 43 Mev
r
=
%S
;
or
v
=
i
a
-
:
~ 224 Pa
566 Mev
.
WMAP TH reg TAO:
~
63
i
Bo
Channe!
i
ze
!
No
Fig. 1. 2-Spectrum of ?39Pu, °?8Pu, ?2°Pu, °°8Th and 27+Ra,
Thorium. however. does follow plutonium in the hydroxide precipitates and
is not effectively cleaned up by the nitric acid elution (necessary for separation of iron
from plutonium) on the anion-exchange column. nor. on this column. by hydrochloric
acid elution: Stubborn traces of thorium continue to elute atter many column-
RESUME
]
des éch
sensibil
100 g)e
par cor
nitrique
adheres until eluted with hydrochloric acid-ammonium iodide whereas thorium Is
ZUSAMM
quickly washed out with concentrated acid.
tamer tepee
Jarge sa
per 100
sample,
hydrox
water. ;
sedime!
and bla
volumesof this acid. This is probably because of strong adsorption of thorium-nitrate
complexes in the interstitial cavities of the resin beads, where the hydrochloric acid
wash may be physically restricted. Use of a second anion column, equilibrated with
hydrochloric acid, has proved necessary and effective: On this column plutonium
Other parameters
Two kindsof material, platinum andstainless steel, were studied for the mount-
ing of plutonium for a-spectrometry. Stainless steel discs were chosen because they are
considerably less costly than platinum and the quality of the plated sample is not
significantly different from thatof the platinum disc in terms of both a-resolution and
adhesion of plutonium to the plate.
Theresolution ofthe spectrometer used for the 5.76- MeV x-emission of 73° Puls
60+ 5 keV (FWHM) on stainless steel discs as compared to 65+5 keV for platinum
Anal. Chim, Acta. 36 (1971) 35 5-364
500u281
ment.
contrac
548 Mey
Lf
cal
r
directh
<36p.
t
f
standa
~ counte
SUMMA!
HE
bF
Know!
beaker
Institut
4,
L
5
e
4
53 aM vs
~ ) pe
p
— PE en ere ee
*
515 Mev
~
.
[
I
|
-
«2a
yee
deel Hit ak Sok ihe oh inltaco
tei tate
—
ail
en
Te tans Maal, Mecca:
wd
discs. .
detect
than il
T
fT
as
228Th. which is present. as a decay product. in the ~*°Pu tracer. as well as being very
rich in most recent marine sediments. and detectable in marine organisms. Radium224 is no problem in the method described since 11 does not follow plutontum in the
hydroxide precipitation.
‘
geometry. of thorium-228. and radium-274 in this energyregion. [tis clear that -** py.
the least abundantof the plutonium isotopes measured, is seriously interfered with by
Tecan apsed
teh ee
7
ees
acl.
:
ee:
ve lee
PLUTO
kh. M. WONG
cr
rapa Lie ict Paes ba nit bl we ini ar, aed: oh = baa
362
Divers |
I
grossen
lichkeit
in Sedin
Probe) t
wird ein
aschte C
zogen. [
b-einflu