Lanthanum 100g 99.9% (with significant Ac227) contamination

[Ben H]

So after many months of waiting, I built my main detector 63mmx63mm NaI(Tl) NOS Ukrainian crystal and I'm very pleased with the results. Now waiting for a Cs137 to get a good idea of resolution.

Here is a spectrum of 100g of pure Lanthanum metal that @Gigabequerel and I ordered from Onyxmet. The expected La138 peaks are there, along with Ac227 peaks. I believe is due to the chemical similarity of Actinium and Lanthanum and so it gets caught in the separation process.

[Sesselmann]

Ben,

Nice result, nice how Interspec gives so much more information about what we are seeing, it gives that extra confidence and explains why some peaks appear wider etc.

Steven

[GigaBecquerel]

Here's my take on that sample!

As you can see Ben has a lot lower lead XRF, just because he has less lead, and some copper to stop the XRF.
Ac227 has a half life of ~20 years, and it will be very interesting to look at the sample every few years to compare it, and watch the Ac decay.

Interspec is one of the best tools one can use for gammaspec, mainly because of the database. It has "all" radionuclides, XRF and even n, g reaction gammas, it shows daugher buildup over time and even guesstimates the age of your sample based on that.
Here you can see extensive use of the "deconvoluting" feature, where it recognizes a peak consists of multiple lines, and tries to identify them.
I'm happy with my NaI spectrum, now I'll take one with my LaBr. This is close to ideal, as its intrinsic background will barely change the spectrum :P

Lukas

[iRad]

Nice work Ben. I'm glad to see that the Hamamatsu R6233 is working well with the 63X63 crystal. Nice build. Tom

[Ben H]

Thanks Tom, it's been working great so far!

[Go-Figure]

Here is a spectrum of 100g of pure Lanthanum metal that @Gigabequerel and I ordered from Onyxmet. The expected La138 peaks are there, along with Ac227 peaks. I believe is due to the chemical similarity of Actinium and Lanthanum and so it gets caught in the separation process.

Lanthanium is something I've been thinking of testing for a while, but I couldn't figure out where to find it. Now I will try with Onyxmet.
Nice result by the way!

Massimo

[GigaBecquerel]

And here's a HPGe spectrum, clearly showing Ac, La (And Ra & K, because the detector isn't in a proper lead shield)

[Sesselmann]

Nice HPGE spectrum, how many hours does it take to get that spectrum?

Steven

[GigaBecquerel]

This spectrum was taken with a realtime of 4.3*10^4 seconds.
Most HPGes are noticably less efficient than scintillators, just due their size (this one is 25% relative efficiency of a 3x3" NaI), but on the other hand yoh need way less counts to make the peaks stand out.

[Sesselmann]

Ahh.., you mean 10 hours :)

Steven