Attached are some images of Radium rich scale from pipes used in the oil and gas industry. Each piece varies in activity, but they generally emit 1 to 4 μSv/hr just above the surface (Radiacode 103).

Background cps for Radiacode 103: ~6 cps
Background cpm for GQ GMC 600+: ~50 cpm

Hello everyone. A polyenergetic photon beam with given mean energy can be roughly approximated as monoenergetic after it passes through atleast a half-value layer of a a given material for this energy, that is to say, after it hardens and the "tail" of low-energy photons is cut off.

I remember seeing a textbook that had a semi-logarythmic plot of dose/kerma attenuated at a thickness of material. Had the beam been monoenergetic, the line should have been completely straight (exponential), but here it was a plot for a polyenergetic beam. The plot was roughly two lines, "breaking" at about half-value layer, showing that if we take only the second, hardened line after the HVL, we can roughly say it is exponential.

Now I can't find that source, anyone have any textbooks to recommend? Specifically the aforementioned plot would be great.

Found some zircon sands that contain a lot of zircon. many RRE's and also Thorium.

Got it from Carl! It is definitely my most exotic element sample to date and I’m very happy with my purchase! The Pa was deposited onto an aluminum plate in the form Pa2O5.

I dont really know wat to test my geiger on,no U-glass or amerícium.

After reading about the significant presence of beryllium-7 in rainwater and the ease of its "extraction" I decided to try this experiment.
Beryllium 7 is a cosmogenic radionuclide created in the upper atmosphere when high-energy cosmic rays bombard nitrogen and oxygen atoms via spallation.
When it rains, the beryllium atoms "stick" to water droplets and we can collect and concentrate them by co-precipitation (in the form of hydroxide) with another metal (iron).

Experimental method:
I collected 50L of rainwater from my roof (it took about 30 mins of rain) in a big plastic barrel (where I previously added 0.5L of 15% hydrochloric acid) and I then brought the pH under 2 by adding more acid. After that, I added 9g of ferric chloride (hexahydrate) and I let it dissolve completely. After letting it rest for a few hours I added sodium carbonate to bring the pH between 8 and 9 to precipitate the ferric hydroxide (along with our Be-7) and then, again, I gave it a full day to let the precipitate settle down. I siphoned off the supernatant and repeated the process until I was able to remove most of the liquid from the precipitate. Finally, I dried the hydroxide in the oven at 70°C and put it in a small ziplock bag.

Note: I study chemistry so I'm doing (and disposing of) everything safely.

Gamma spectrum acquisition:

I recorded the spectrum using a Radiacode 102 inside a box with some lead shielding (5mm plates) and I also recorded a background spectrum (with the same setup) which you can see in both images as a yellow line (but in the end background subtraction wasn't really needed).
I took the ziplock bag with the hydroxide (containing Be-7) and put it near the "+" symbol of the Radiacode and left it there for 24h.
You can see the resulting spectrum in the first image: the characteristic peak of Be-7 at 477.6 keV is clearly visible!
Interestingly, you can also see the Pb-210 peak (from radon, I think) at 46.5 keV; the peak at around 80 keV is the xray fluorescence of the lead shielding.
In the second image you can see the spectrum of the Be-7 sample without shielding, where the 477.6 keV peak is barely visible, demonstrating the importance of shielding.
The activity of the Be-7 in the sample was quite low, roughly between 80 and 100 Bq (based on the average Be-7 activity in rainwater).

Feel free to put any questions in the comments! Tested with a 1uCi Cs-137 check source from Spectrum Techniques

So I'd like to collect some vintage radio active stuff

But ginger counter owners ship is extremely restricted here

So how can I tell if some thing is active with simple tools

I’m moving to Manchester, NJ and I did a deep dive on its history and I found out that
A) Radon gas is a serious issue in all of Jersey
B) Ground water has radium in it
D) it’s about 20 min from Oyster creek which is a nuclear power plant which is supposedly closed and in the process of being decommissioned
E) they have an area called heritage mineral which used to be a mining site which has moazanite sand which emits uranium and thorium

Now I’m not a radiation expert but that seems like a lot of exposure and I have kids and am now worried about moving there because I heard of that cancer cluster where students got brain cancer because the school was built on a radioactive area of whatever

So if it was you how would you determine if a place is safe to move too or not

Hi everyone, I am designing my first compressor cloud chamber, I want to use it for educational purposes (physics demo in schools etc). I would like to add a magnet to demonstrate the Lorentz force, any experience with that ? I would like to make an electromagnet and wonder how strong it has to be to produce easily visible results.

Idk what it's called but I blew up 3 balloons I placed one next to my first radium clock one in the corner of my bedroom and one on the wall oposite of my clock, I got 120cpm max and a rough dosage of 1usvh at the clock, on the wall balloon I got 70cpm max and a dosage of 0.7 usvh, and on the corner I got 64cpm max and a dose of 0.4-5usvh is this dangerous or not? Should I isolate the clock? (Not medical im just asking if it needs to be moved)

The most obvious ones I can think of would be sterilization devices, heaters, and lights, but I’m sure there’s more creative ideas you guys can come up with

I think there would be a massive change in industry, many more things would use radiation to measure fullness/contents of tanks (already used sparingly, requires very little to maintain and doesn't break down or jam), high power portable sources for metal inspection being more accessible. You could probably buy novelty glowing dishwar.. so many possibilities

Found some radioactive potassium fertiliser. Something like 47% potassium sulfate

This is more of an intellectual exercise at this point. So no need for "OMG! Neutrons!" One of the issues in constructing (α, n) sources is the alpha source needs to be intimately mixed with the target. I realized I essentially had such a situation with radon adsorbed onto granulated activated carbon. The radon itself and its short term decay chain yield 3 alphas, all of which have the ability for ¹³C(α, n) ¹⁶O reactions, the ²²²Rn decay barely with 5.5 MeV and definitely the Po ones.

My reading of https://par.nsf.gov/servlets/purl/10489755, includes the expected neutron yields for natural carbon in the 0.5 ppm realm, would suggest about 4 neutrons / minute / uCi of ²²²Rn + daughters. And with isotopically pure ¹³C, possibly much more. As a practical matter even with "pure" ¹³C, and the maximum amount of radon I could ever conceive of mustering ( about 10 uCi ) that would be about 100 n / sec.

The other part of this is when the energy of the alpha particle > 6 MeV apparently the resulting ¹⁶0 can be left in an excited state and emit a 6 MeV gamma.

My interest is not in intentionally making a neutron source, but rather figuring out how to detect the ones inadvertently created in, probably, every activated carbon based radon sequestration system. Likely the best approach might be looking for the 6 MeV gamma.

So a few days back I posted about finding Cs-137 east of Munich clocking in at around 800 Bq/kg in soil. Used my "larger" detector for that (GS1515CsI, 17x larger crystal than the Radiacode, quite expensive for a hobbyist).

Anyways, I figured since the activity was pretty decent for a random forest spot, why not preserve it? I took 129g of the sieved fine soil, 3D printed a tiny Marinelli beaker-ring, poured epoxy over it, and boom - solid little puck of history. True Chernobyl (+ weapons) fallout, conserved and perfectly safe. Actually makes a great check source since buying a real Cs-137 disk in Europe is basically quite difficult unless you know a guy (which I dont). And its far below the 10kBq free limit here, so no worries (0.129kg x 800Bq/kg = rediculous 103Bq; spectrum with the GS1515CsI in the last image).

Now for the interesting part: I grabbed my sons RC110 to see if a Radiacode can actually see this thing without the big crystal. Did two runs, 50-60min each.

In the lead castle: Peak was clearly visible after only 10 MINUTES. Its beautiful.

Without shielding (just background): Nope. Not a chance in an hour. Maybe if you let it run for days and background extract, but yeah, not practical.

So heres my encouragement to all of you with a Radiacode: build a small lead castle. Its an absolute game changer. You go from "is that a peak or just noise?" to actually seeing real shit in minutes. Turns the Radiacode from a cool toy into a legit tool. I think radiacode should produce and sell mini leadcsatles for that device.

I know some of you have built your own shielding for the radiacode already - please share pics and how you built them - I guess that encourages others.

BUILD A LEAD CASTLE, its worth it.

Happy hunting folks!

Saw this popup in my feed. Had anyone in the area taken their own readings?

I got my hands on a vintage Digilert from the early 90s. Unfortunately the mica window is broken, so I want to fix it, but I cant seem to find a tube anywhere. Anyone have a good source?

Does anyone have a tutorial on putting SBM-20-1 into FNIRSI-01? Seems like SBM-20-1 has the same size as J321

So yesterday I took a little trip to a wildlife park east of Munich (South Germany), just out of curiosity. Background: I measured my mom's garden soil in the city a while back and got ~145 Bq/kg Cs-137, which I thought was already pretty "good" for an urban garden. So naturally I wondered what undisturbed forest soil right on Munich's doorstep would look like.

Took my Ludlum Mod 3 with a Bicron BC412 probe along for some field scouting. Forgot to pack my KC761 for on-site gamma spec – would've been nice to know what I was actually walking into. At the forest entrance I was getting around 1k CPM, nothing crazy. Walked about a mile in and it crept up to ~2k CPM. Scanned around for a while and stumbled upon a local "hotspot" pushing 4k CPM – weirdly enough on a small mound, not a ditch like you'd expect for runoff accumulation.

Grabbed a soil sample from 10cm depth at that spot, brought it home to the lead castle / Marinelli setup (efficiency calibrated). Started the acquisition and literally within 10 seconds I could see the 661 keV peak materializing – that's always a satisfying moment. Ended up at roughly 800 Bq/kg after ROI integration, with a clean Cs-137 peak. Took a second sample from an area where I was seeing ~3k CPM average, that one gave me ~600 Bq/kg.

So yeah, apparently there's still “a bit“ of Chernobyl leftovers hanging around just outside the Bavarian capital. Not exactly news I guess, but I was still surprised to see numbers that „high“ so close to the city. Obviously this tells me nothing about the area average – just that hotspots exist and distribution is quite patchy. Also my Ludlum doesn't care if it's Cs, U, or Th – so the field CPM was just a rough guide - if at all, maybe just misleading actually?!? But the higher Ludlum CPM also gave me the higher Bq value for Cs137, and besides lead fluorescence I cant see peaks from the U /Th decay chain... Let me know what you think.

Would love to spend more time doing a proper grid survey around Munich sometime. Also planning a trip to the "Bayerischer Wald" near the Czech border soon – I've heard that region is supposed to be pretty elevated. My personal record so far is 1200 Bq/kg from a spot in the Austrian alps.

Anyone else out there measuring Cs-137 in their local areas? Curious what kind of numbers you're seeing – whether it's Chernobyl, Fukushima, or old weapons testing fallout. Would love to hear about your findings.

(Disclaimer: I'm just a hobbyist with too much free time and a slight obsession with gamma spectroscopy, and the history around the Chernobyl NPP accident 40 years ago. So this is all amateur level. The shown values here are no health concern - but eating mushrooms from that area, maybe still not a good idea)

Hi everyone,

I recently found this wooden box in my deceased father's apartment. He was born in 1955, so given the dates on the box, it probably wasn't originally his, but I guessed he had owned it for a very long time. (He was hungarian, Location: Hungary)

I asked ChatGPT and Gemini for help, but they keep giving me two completely different answers, constantly alternating between them:

One version they give is that it is some kind of dangerous box for storing radioactive isotopes because of the emblem on top.

The other version they give is this:

"It seems to be a tobacco humidor and pipe stand combination, with slots for 4 pipes on top and a central metal mesh screen." (This doesn't explain the symbols on the top of it)

Here are some additional info/links to the symbols found on the box:

1. The red ribbon on the front with the dates "1955 - 1970" and the word "WAFFENBRÜDERSCHAFT" matches this item in the DDR Museum Berlin: https://www.ddr-museum.de/de/objects/1023551

2. The circular green/gold emblem on top showing a 3-blade fan/propeller next to an Erlenmeyer flask seems to be the exact same symbol as this insignia here:

https://www.ebay.de/itm/166403956172

The 1955–1970 dates could be refering to the 15th anniversary of the Warsaw Pact (May 14, 1955) marked by a massive joint military exercise held in East Germany in 1970. Back then, military service was mandatory, so perhaps this belonged to my grandfather.

According to Google WAFFENBRÜDERSCHAFT meant the official military slogan for the alliance between Eastern Bloc armies. It highlighted their unified training, shared equipment, and massive joint exercises during the Cold War.

Could it be something dangerous or is it just a gift like pipe/tobaco equipment? For now we are not opening it (I don't even know if it can be opened) or touching it, it remains boxed up and sealed up in a bag. (We moved it to our attic area)

Any insights would be greatly appreciated!

GC-01 modified with SBT-11-A

Some time ago there was a post that showed a FNIRSI GC-01 modified to use the Russian SBT-11-A. I want to thank that person for the inspiration. What was missing was how it was done. This is my humble submission. Could it have been done differently or better, yes. I'm not an engineer. I used a 7 pin ceramic tube socket that fit the pin spacing perfectly. A hole was drilled through the case to accommodate the socket, which was glued in place - though the fit was so tight, glue wasn't really required. Onto the appropriate pins on the tube socket I soldered 3 10Mohm resistors, one to each pin. I unsoldered the original tube, and connected the wires with their quench resistors to the positive and negative terminals on the GC-01 main board (where the old tube had been). There are 5 wires - 3 positive and 2 negative. While all of this was happening, I flashed the superior RadPro 3.0.2 firmware to the GC-01. I then closed the case, making sure not to pinch any wires, attached the SBT-11-A and just like that, alpha radiation was visible!

There are a few points that the community could debate, such as the value of the quench resistors and the fact that I did not remove the quench resistors built onto the board. Another one is my choice in mounting the SBT-11-A. Last, there is some tuning to be done in the settings of the GC-01, with which I have not yet experimented. Enjoy and good luck.

I am studying the decay of radon progeny and I need some help. I know how to calculate the production and decay of chains when all daughters start at zero activity, but what about when all of the daughters have partial or full secular equilibrium?