Increase in radiation from radium pocket watch hands

[Makarov_711]

TL;DR Summary

I ran 2 tests of 12 hours, one of the tests involved a piece of beryllium being placed on top of radium pocket watch hands, there was an increase in radiation over a 12 hour period compared to the test without the beryllium. Why was there and an increase and was I detecting protons?

Hello, I'm new here and recently did a little experiment in my free time that left me puzzled. To sum it up I ran 2 tests, each running over 12 hours long, they where focused on 3 radium pocket watch hands that I bought off of eBay a while ago and a small piece of beryllium. These hands are pretty miniscule, they are for a pocket watch and combined they only have the activity of about 1 to 2 microcuries. During the first test I placed the hands in an assembly made of paraffin blocks, only a few centimeters in length and about ~2 centimeters in width. 2 Blocks of paraffin rested atop the watch hands although they where held up by some coins to prevent the wax touching the hands, they had a total thickness of 3.8 CM, I placed my Geiger counter on top of this and left it running for 12 hours. When I came back its total count was 14,781 counts in 12 hours. I redid what I stated above but before placing the wax on top I placed a piece of beryllium right on top of the watch hands, once again this was then covered by 3.8 CM of paraffin before letting the counter run for another 12 hours. After the 12 hours the counter displayed an increase of 294 counts, 15,075 in 12 hours compared to 14,781. Does anyone know what this kind of radiation is and why it happened? I do know that beryllium spits out neutrons when bombarded with alpha particles but they are neutral and wouldn't be detected by my counter, I read some sources that say that paraffin wax releases protons when struck by neutrons, could it be proton radiation?

 

[Drakkith]

First and foremost, a difference of 294 is not even a 2% difference and could be explained by differences in the placement of the parts of your setup in between the two experiments. Even random chance could have caused this, as 294 is within one or two standard deviations. If you're up to it, I'd suggest doing a few more runs just to make sure.

Also, what kind of meter were you using? "Geiger counter" is often a catch-all term for any radiation detecting device. Can you give us the specific model and other such info?

 

[Makarov_711]

I'll do another few tests when I find the time, as for my Geiger counter I am using a GQ GMC 300E Plus, it uses the original M4011 tube but with the back cover removed, the plastic cover blocks out a significant amount of radiation that I would not have detected otherwise. I am probably going to get something more sensitive in the future, I heard scintillators are better than gas geiger counters.

 

[Vanadium 50]

First and foremost

No, that's second. First is paragraphs! Hacking through a jungle of text is painful.

The uncertainty on the difference between two numbers around 15000 is about 175. So 294 is not significant. You get a difference at least this large about 1 time in 6.

Also, 12 hours might not be 12.0000 hours. A few minutes to start and stop and this becomes even more probable.

Positioning the watch hands to within a percent or so sounds tricky. That can also affect the result.

Here is what I would do. You need 10x the data pr sp to see an effect of this size. So do maybe 8 runs each of 16 hours (so you aren't always doing it at the same time of day for the two configurations) alternating the configurations. You can then compare the variation between two dufferent confgigurations with two different runs of the same configuration.

Once we know if there is an effect, we can then think about why.

 

[gleem]

TL;DR Summary: I ran 2 tests of 12 hours, one of the tests involved a piece of beryllium being placed on top of radium pocket watch hands, there was an increase in radiation over a 12 hour period compared to the test without the beryllium. Why was there and an increase and was I detecting protons?

2 Blocks of paraffin rested atop the watch hands although they where held up by some coins to prevent the wax touching the hands,

This suggests that the watch crystal is removed. If so this can be dangerous as the radium compound on the watch hands can flake off and contaminate the surrounding area or you.

The Beryllium alpha reaction also produces gamma rays which are detectable by the GM counter.

 

[Vanadium 50]

Beryllium is dangerous too. I am assuming he is handling everything properly.

But before we go about trying to explain the effect, we need to find out if it is real.

 

[mfb]

What is the count rate if you don't have the radium watch hand (but keep the rest of the setup)?

I read some sources that say that paraffin wax releases protons when struck by neutrons, could it be proton radiation?

At the energies discussed here it's stopped about as easily as alpha radiation.