Bavarian Mushrooms - Maronen - CS137 and RadioactivityCounter Android App

In the Bavarian forest mushrooms still show radioactivity (CS137) from the Tschernobyl accident. Especially Maronen are CS137 collectors. We used a super sensitive Pancake Geigercounter for demonstration and for comparison also the RadioactivityCounter App for Android mobile phones, which can also detect the activity of the mushrooms. The Pancake has a10:1scale in comparison to the Standard Detector for this Geiger model, the alarm trigger was set to 2 uSv/h (which means 0.2 uSv/h for the Pancake.) Here we were lucky to see some hits on the phone immediatly, usually you need at least 10-30min to get a precise value (mean) as the 2mmx2mm area of the detector is very small. Single hits causes multiple counts as the energy is also important and secondary electrons are also counted on neightbar sensor cells. The camera sensor is used for detection, they differ from brand to brand in sensitivity - on our homepage you find more infos. Also here beta and gamma rays are counted - for activity calculation on CS137 only gamma rays are used normally (same for K40 which only has around 11% gamma rays in comparison to the weaker beta rays) K+K40 is normally replaced with CS137 by the mushroom, as the chemical behavior is similar to them.

Category:

Education

Tags:

• bavarian
• mushrooms
• radioactity
• CS137
• forest
• Android
• RadioactivityCounter
• App
• mushroom
• pilze
• radioaktiv
• radioactive
• measurements
• Messungen
• Maronen
• Iphone
• Android (operating System)
• Ipod
• Mobile
• Mobile Phone
• radioaktive

[rolfdieterklein]

For most phones the nosie of the sensor varies too much. If you have a old radium watch this will really work very well, also URAN Glas (much weaker), or Thorium dotted lenses (for example SMC Takumar or SUper Takumar of a specific series), very strong sources with >10 uGy/h.

[rolfdieterklein]

but you need to shield to phone with lead before the measurement and then including the KCL - otherwise the KCL will shield some of the natural radiation). KCL has around 6 Bq per gramm. But with a kg is a large volume or surface and the sensors of a phone are small !.

Granit usually has some gamma radiation but not a high activity (we tested and got around 0.4 uGy/h at the surface of a block) but that can differ very much. --->

[rolfdieterklein]

@pauxps it does work with mushrooms, they had around around 1 uGy/h directly at the surface. We hope to repeat this next time being better prepared with some devices.

Bananas with K40 are too low to see some counts. K40 is a strong beta radaiator, but this will be blocked and some gamma which is to far apart. We tested a KCL source with the best phone we had (potassium Chlorid E506 used for food supply), then you can see an increase, --->

[MucusFelidae]

Noch eine Frage, falls es dir nichts ausmacht. ich weiß, das Schwammerlsucher gerne alleine unterwegs sind und alle die fragen, in die andere Richtung schicken, aber vielleicht kannst du uns sagen wo diese Örtlichkeit ist. Dieser Marone wird wohl schon weg sein, sonst hätten wir ein Kalibrierschwammerl.

[rolfdieterklein]

@MucusFelidae Das war im Raum Regenburg vor ein paar Wochen, mein Kollege hat relative lange nach einem Pilz gesucht der auch merkbare Reaktion zeigt, der Pilz ist leider nicht mehr vorhanden (auch nicht gegessen worden). Bei der nächsten Schwammerlsaison ist er gerne bereit mal jemand mitzunehmen.

[MucusFelidae]

Hast du das Schwammerl geimpft & gesalzen oder ist das echt echt?

[rolfdieterklein]

@MucusFelidae Der ist wirklich so gewachsen, man hoert auch genau wo das Mycel unter der Erde ist, da dieses ebenfalls belastet ist. In der Tat gibt es noch viel stärker belastete Pilze, je nach Region im bayerischen Wald unterschiedlich, vor allen Dingen die Maronen sammeln das CS137 aus dem Boden und konzentrieren es auf. Und dann die Wildschweine die es wieder fressen sammeln das CS137 ebenfalls auf. Bei google findet man unter "maronen cs137" einige Statistiken und Informationen.

[pauxps]

It's not entirely clear for me: Does the video show at 0:52 that the app *does* work or does *not* work with this mushroom? Are the displayed values accurate or too low? I ask because there are hardly any counts.

Can I test your app without a dedicated radiation source? E.g., I heard that bananas have a high natural radiation level. Can your app capture that? If not, what could I try instead? Granite? (Mushrooms?)

[rolfdieterklein]

@rolfdieterklein where CS137 has intense gamma spectras originating from 137Ba(m) decay to 137Ba (g=661,66 keV but also beta with 513 keV and 1175 keV from CS137 to 127Ba(m) )

[rolfdieterklein]

@p212121v Yes we tested K40 as KCL (possasiumchlorid = E506) seperatly, even 1kg of pure KCL has much less reaction on the geigercounter than those mushrooms (though activity is 16000 Bq/KG but the most is absorbed by itself), especially K40 is mainly a beta radiator (e=1311,09 keV max with 89% and some gamma from positron annihilation and from Ar-40),