Please refer to the decay chain for U-238 on page 2 of this chart,
if you do not have one printed already:

http://www.ead.anl.gov/pub/doc/natural-decay-series.pdf


Going down the chain, looking at only Gamma energies right now, with
a computerized-spectrum analyzer, the SpecTech UCS-30 and a 3" X 3" sodium iodide detector.

At the top >U-238. The parent of this decay chain. Other decay chains
are headed by Th-232 and U-235. Any isotope removed by man or nature from
a chain,will be considered the head of it's own chain, as in Radium , Radon,
or even Radium D+E.>
Right at the top there is an X-ray at 100 keV and Gammas at 185, 766
and 1001 from the Pa-234m. If these are present, parent U-238 is
present, and by default all the other lower daughters should be there, if they have not been removed by
man or nature ( Radon is a gas, it can fall away, being heavier than air,
disturbing the lower part of the chain)
Pictures of this and all the other graphs can be seen at:

http://groups.yahoo.com/group/GeigerCounterEnthusiasts/files/
Look at the far left side for those telltale energies from the higher
parents.

All the graphs will show some Gamma from K-40 at 1460 keV. This is
not from the test sample, but part of the background radiation here at my place. Some
of it may even be my own bones (see graph of chicken bones later on!).

Down the chain is Radium 226, a strong alpha emitter, with a weak
Gamma, which is undetectable by my home lab setup. The Alphas of course are
easy to detect, but hard to tell from other Alphas generated later down the
chain.
Radium was first refined over 100 years ago. When it is removed
that way from the surrounding U238 parent, it starts it's own decay chain,
which is simply a continuation everything below it on this chain.

Pb-214, or " Radium B" is quite detectable with a Gamma
Scintillator, with a striking 351 keV Gamma. Likewise "Radium C" also known as Bismuth-214,

which is the next in line of decay. It has a 609 keV, 1112 keV and a 1760 (unique) keV Gamma.
If these two are present, then parent Radium-226 is present. ( The
letter designators are little used any more, scientists simply call an
isotope by it's name and weight)


Way down near the bottom is Radium D+E. Today known as Lead-210
(radiolead) and Bismuth-210. No Gammas detectable from these, but you know they
must be in the mix if the higher members are present. Lots of Betas though.
It is possible that D+E alone have been removed, and used in a test
spot, easy to determine, simply by the absence of Gammas from the higher
members Pb-214/Bi-214.

So by logic:
Got Betas, no Gamma?= Radium D+E only. Black, crumbly

Got Betas + 1760 keV Gamma (Bi-214) but no 100k X-Ray or Pa-234
Gammas?= Radium-226

Got Betas+1760 Gamma + 100k X-Ray and the Pa-234 Gammas?= Uranium-238. Grey, hard

Has the U-235 been removed from natural Uranium, a.k.a. DU? The presence or absence of a 185 keV peak easily determines the

state of U-235 in a sample.

DU metal and U oxide are way different creatures, physically. DU
metal is used in ammo yes, but also for it's density and weight value in airliners, ocean
liners and sailboats as ballast.

Last winter I handled and measured a big chunk of the stuff at White
Sands Missile range. Pretty radioactive according to my pocket Geiger, and
not just Alphas, as it was in a plastic bag.


Now on the CDV 700 test spots.

Anton= Radium-226. Why ? Because it has the Pb-214 and Bi-214 that are
present
when Radium 226 is the parent. Further, there are no higher Gammas
from the
Pa-234, ruling out a higher parent. This is the only metallic
appearing
material I have seen, I assume electroplated(?).
Spectrum available in the above mentioned files.

Anton's books state D+E. Why this is I don't know. It's true D+E are
in
there, they have to be, as they are the lower decay daughters. Their
D+E
will not deteriorate though,as it is continuously replenished by the
Radium-226. Perhaps not all the Anton's have the
metal foil. The only 2 I ever opened did, one was a model 5, on a
model 6.

ENi 6B: some books say Radium D+E some books say Uranium. All have
tested
here
are D+E. Many of the ENi's I've seen ( maybe 100?) have deteriorated
activity from the test spot ( 21/2 half-lives old now after all)
Update:
Some ENI's have normal 2+ "mR" strength test spots, but seem to have
been
tampered with. Perhaps in some programs, they were renewed at some
point.
(Geo)


Victoreen Instruments: CDV 700 books for 6, 6A and 6B say "Beta
Source".Vic
491 book says Uranium. In fact, by measurement, some are natural
Uranium,
theses have a hard dark gray brittle material. The majority I've
tested are
the black crumbly stuff,
D+E. From Bill Kolb, author of "Living with radiation":
From: "William Kolb" <analemma@...>
To: "'K0FF'" <K0FF@...>

>George,
> The Victoreen Cutie Pie used natural uranium for its check source.
It is
> primarily a beta emitter but you will see lines just below 100KeV
(U-K
> xrays), at 185KeV (Pa-234), 766KeV (Pa-234m) and 1001KeV (Pa-234m).
The
> Nuclear Chicago Cutie Pie had a C-14 beta source. As far as I know,
> Victoreen only used natural uranium on its meters, including the
> CDV-700s.
>
> bill
>


PRI books say Uranium Ore for the 106B, and "calibrated Radium" for
the
107B, 109, 110, 111B, 111C. Look at the PRI spots in the dark, some
glow!

Lionel definitely D+E....no Gammas present, just the Betas.


Just a reminder that any Alphas present in a covered sample will be
filtered
out by the covering material. Only Beta and Gamma can escape the
cover material.

 

 

 

 

Have Fun

Geo