alpha emitter

Discussions about radiation-related science
Post Reply
User avatar
Peter-1
Posts: 143
Joined: 07 Oct 2016, 01:45
Location: Germany
Contact:

alpha emitter

Post by Peter-1 » 30 Apr 2020, 19:21

Looking for a pure alpha emitter i came up with the following idea. Samarium 147 is a pure alpha emitter and contains 15% in natural samarium. You can buy samarium in many countries. According to a research, the activity should be around 850 Bq / gr. What is to be thought of this idea?
Samarium147a.jpg
Samarium147a.jpg (70.6 KiB) Viewed 770 times
Peter

User avatar
Peter-1
Posts: 143
Joined: 07 Oct 2016, 01:45
Location: Germany
Contact:

Samarium

Post by Peter-1 » 05 May 2020, 01:11

It did not work !
I received a small sample (10 grams) of samarium and hoped that I would be able to demonstrate the activity with a detector for alpha radiation. The semiconductor detector is very sensitive to alpha radiation which I have previously tested with Am241. Who has an explanation why I could not find any radiation? In order to be sure that it is also samarium, i tried the x-ray fluorescence.
Some pictures of the experiment.

Samarium
Samarium-01.jpg
Samarium-02.jpg
detector
SFH522.jpg
x-ray
2020_05_01-X-ray-Sm.jpg
Peter

User avatar
Geoff
Posts: 120
Joined: 01 May 2015, 12:21
Location: Marathon County, Wisconsin
Contact:

Re: alpha emitter

Post by Geoff » 05 May 2020, 07:19

Not sure why you didn’t get results, but I have a couple thoughts. First, I think samarium would be closer to 130bq/g. Second, only the outer layer of the surface facing the detector would be an alpha source? I’m not sure about alpha particle interactions with matter, but wouldn’t a thin sheet of the metal provide a greater surface area that the detector could face? The shape of your sample makes me think your detector would be seeing single digit counts per second at best.
Geoff Van Horn

Former Alaskan living in rural Wisconsin

User avatar
sgt_bear
Posts: 87
Joined: 16 Jan 2017, 07:06
Contact:

Re: alpha emitter

Post by sgt_bear » 12 May 2020, 04:59

The specific activity of Sm-147 is 843.9Bq/g, since only 15% of Samarium are Sm-147 this would result in 150mg Sm-147 per 1g of Samarium, therefore Samarium would have technically 126bq/g.

But since its an alpha emitter, most of the radiation will get blocked by the material itself. The radioactive particles from "inside" the source don't make it to the surface and are therefore not visible to the detector. Imagine a pack of steel balls that are mixed with concrete and poured in a block. There might be a lot of balls inside, but you only can see those who are making contact with the surface. Also samarium oxidizes heavily in air, so the oxyde-layer possibly even shields more.

If you are looking for a pure alpha emitter, maybe Pa231 would be your option.
https://www.novaelements.com/protactinium/ , maybe you can get a non "resined" one
- Jonathan from Switzerland

User avatar
Peter-1
Posts: 143
Joined: 07 Oct 2016, 01:45
Location: Germany
Contact:

Re: alpha emitter

Post by Peter-1 » 13 May 2020, 00:43

hello Jonathan,
I took more time and examined different samples. It is clear that the samarium gives so little impulse, but at least I was able to prove it. In order to be absolutely sure that the impulses do not only come from the background and the noise, I measured the background several times. What surprises me is that the uranium glass clearly sends out alpha particles. Here my compilation of the measurements.
Tabelle.jpg
Pechblende-06.jpg
Pechblende-06.jpg (110.42 KiB) Viewed 544 times
Uranwürfel.jpg
Uranwürfel.jpg (68.22 KiB) Viewed 544 times
Trinitit-25mm.jpg
Trinitit-25mm.jpg (109.65 KiB) Viewed 544 times
Granite
Granit-01.jpg
Granit-01.jpg (79.12 KiB) Viewed 544 times
QuantumPendant
Quantum-03a.jpg
Quantum-03a.jpg (97.98 KiB) Viewed 544 times
Peter

User avatar
Geoff
Posts: 120
Joined: 01 May 2015, 12:21
Location: Marathon County, Wisconsin
Contact:

Re: alpha emitter

Post by Geoff » 13 May 2020, 01:07

Are my comments not showing up?
Geoff Van Horn

Former Alaskan living in rural Wisconsin

User avatar
Peter-1
Posts: 143
Joined: 07 Oct 2016, 01:45
Location: Germany
Contact:

Re: alpha emitter

Post by Peter-1 » 13 May 2020, 01:17

yes it agrees well with the comments.

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests