Mike Monett <spamme@not.com> wrote:> dplatt@coop.radagast.org (Dave Platt) wrote:>> Also on eBay, you can find "quantum energy" or "scalar energy" or >> "negative ion" pendants made out of a black volcanic rock. They're >> often touted as a way of protecting oneself from the (supposed) >> harmful effects of electromagnetic radiation.>> The rock from which they are made appears to be rich in thorium and >> its decay products (perhaps something like monazite?).>> I measured one on my home-made gamma spectrometry system and got >> a very recognizable thorium-decay signature (the isotope markers >> are from a best-efforts calibration). >> >> https://www.radagast.org/~dplatt/gamma/quantum-pendant.png> Thanks for the information. I will try to find the black volcanic rock > products. I recall an article describing these that got them kicked off > Amazon (I think).> Thanks,> MikeEbay was a bust. Quantum Energy turned out to be a fishing reel. Scalar energy was some patterns on a piece of paper. However, Amazon turned up lots of volcanic rock emi protectors. I got one titled "Volcanic Stone Pendant,Energy Necklace Fashionable Health Care for Women for Daily Wear Quantum Science Scalar Energy Necklace Round Pendant for Men Woman Tourmaline Volcanic Stone Jewelry", $15.86 FREE delivery August 22 - September 16 https://www.amazon.ca/gp/product/B09V9Y7359/ This one sounds like it will do the job. Thanks. Mike -- MRM
Low Level Gamma Radiation
Started by ●June 5, 2022
Reply by ●July 16, 20222022-07-16
Reply by ●July 16, 20222022-07-16
On Saturday, 16 July 2022 at 21:25:19 UTC+2, Mike Monett wrote:> Mike Monett <spa...@not.com> wrote: > > dpl...@coop.radagast.org (Dave Platt) wrote: > > >> Also on eBay, you can find "quantum energy" or "scalar energy" or > >> "negative ion" pendants made out of a black volcanic rock. They're > >> often touted as a way of protecting oneself from the (supposed) > >> harmful effects of electromagnetic radiation. > >> The rock from which they are made appears to be rich in thorium and > >> its decay products (perhaps something like monazite?). > > >> I measured one on my home-made gamma spectrometry system and got > >> a very recognizable thorium-decay signature (the isotope markers > >> are from a best-efforts calibration). > >> > >> https://www.radagast.org/~dplatt/gamma/quantum-pendant.png > > Thanks for the information. I will try to find the black volcanic rock > > products. I recall an article describing these that got them kicked off > > Amazon (I think). > > Thanks, > > > Mike > > Ebay was a bust. Quantum Energy turned out to be a fishing reel. Scalar > energy was some patterns on a piece of paper. > > However, Amazon turned up lots of volcanic rock emi protectors. I got one > titled > > "Volcanic Stone Pendant,Energy Necklace Fashionable Health Care for Women > for Daily Wear Quantum Science Scalar Energy Necklace Round Pendant for Men > Woman Tourmaline Volcanic Stone Jewelry", > > $15.86 FREE delivery August 22 - September 16 > > https://www.amazon.ca/gp/product/B09V9Y7359/ > > This one sounds like it will do the job. Thanks. > > Mike > > > -- > MRMGamma Radiation is never Low Level beware of cancer
Reply by ●July 16, 20222022-07-16
In article <7cc8f810-1325-4542-bda7-63c76d4195a0n@googlegroups.com>, John Miles, KE5FX <jmiles@gmail.com> wrote:>On Saturday, July 16, 2022 at 7:16:38 AM UTC-7, Dave Platt wrote: >> I measured one on my home-made gamma spectrometry system and got >> a very recognizable thorium-decay signature (the isotope markers >> are from a best-efforts calibration). >> >> https://www.radagast.org/~dplatt/gamma/quantum-pendant.pn > >Resolution of that setup looks really good -- is it written up anywhere?I don't think I've written up anything in detail - it's been a few years since I played with it much. I have a couple of probes, both built with surplus commercial PMTs, one with a NaI(Tl) crystal and another with a BGO crystal. The signal processing uses a charge-sensitive amplifier with some pulse shaping built in (I like the CSA architecture because it's not particularly sensitive to the cable length and capacitance). The original design was done by Richard Hester; I did some tweaks for my version and did a custom board layout. The files are in the https://www.radagast.org/~dplatt/gamma/ directory. The biggest disadvantage to this circuit is that if I forget, and connect or disconnect the probe cable with the power on (or without letting it discharge to zero) the spike usually blows out the front-end JFET, and I have to cuss and pull it out of the air-wire socket and replace it :-) The high-voltage supply is based on a flyback with diode voltage multiplier, based on a circuit I found some years ago intended for use with GM tubes. The output of the CSA goes into a moderately-priced USB sound card line input. I wrote the pulse detection and filtering code myself. The first version was strictly command-line (record audio to a .WAV file, then post-process to detect and bin the pulses and generate data files which could be fed to gnuplot). I then wrote a Linux GUI based on the FLTK toolkit which can read/process/display in real time. The trickiest part was handling high pulse rates, where one pulse starts while the CSA is still recovering from the previous one. At some point I may sit down and try writing some DSP code to de-convolve the CSA's pulse shaping and turn the signal back into narrow impulses.
Reply by ●July 16, 20222022-07-16
On Sat, 16 Jul 2022 18:48:41 -0000 (UTC), Mike Monett <spamme@not.com> wrote:>dplatt@coop.radagast.org (Dave Platt) wrote: > >> In article <XnsAED63FC6A8982idtokenpost@88.198.57.247>, >> Mike Monett <spamme@not.com> wrote: >>>Getting samples of thorium has turned out to be impossible, except for >>>traces in welding rods. However, radium is readily available in the form >>>of watch hands painted with radium. These are for sale extremely cheap >>>on Ebay. >> >> Also on eBay, you can find "quantum energy" or "scalar energy" or >> "negative ion" pendants made out of a black volcanic rock. They're >> often touted as a way of protecting oneself from the (supposed) >> harmful effects of electromagnetic radiation. >> >> They do generate "negative ions", in the form of beta-decay >> electrons... these are not your gentle after-the-rainstorm negative >> ions by any means! >> >> By one report the radiation level is high enough that wearing one next >> to the skin for a year can exceed safe exposure levels and might even >> cause a mild radiation burn. I understand that Singapore has banned >> the import of such products for this reason. >> >> The rock from which they are made appears to be rich in thorium and >> its decay products (perhaps something like monazite?). >> >> I measured one on my home-made gamma spectrometry system and got >> a very recognizable thorium-decay signature (the isotope markers >> are from a best-efforts calibration). >> >> https://www.radagast.org/~dplatt/gamma/quantum-pendant.png >> >> Another useful calibration source (for higher-energy gammas from >> potassium-40) is a sack of potassium chloride water-softener recharge >> crystals from your local big-box home/hardware store (or, on a smaller >> scale, a box of Morton "Lite Salt" which is about half potassium >> chloride). >> >> And, one can still find orange Fiestaware and green uranium glass at >> the occasional estate or garage sale or antique store. > >Thanks for the information. I will try to find the black volcanic rock >products. I recall an article describing these that got them kicked off >Amazon (I think). > >Your gamma spectrometry system sounds very interesting. Can you supply more >information, such as what kind of scintillator crystal do you use, how big >is it, and do you use a PMT or diode for the detector, what software do you >use to generate the spectrum, how do you drive it, and any other details >that might be interesting. > >I use pure potassium chloride (KCl) in the form of Windsor Salt Free >seasoning, but my Radiacode is not sensitive enough to detect the decay >products. I left it sitting on three containers for several days but had no >luck. I need a more sensitive detector, which is why yours is so >interesting. > >On a related topic, I have been trying to find out why the background gamma >spectrum has a sharp rise at low energies, and where does it come from? Do >you have any ideas? > >Thanks, > >MikeThe classic radiation test source was a thoriated Coleman lantern mantle.
Reply by ●July 16, 20222022-07-16
In article <XnsAED696ABEA7D1idtokenpost@88.198.57.247>, Mike Monett <spamme@not.com> wrote:>On a related topic, I have been trying to find out why the background gamma >spectrum has a sharp rise at low energies, and where does it come from? Do >you have any ideas?As I understand it, you're seeing is largely Compton radiation and X-ray fluorescence. When naturally occurring gammas (from K40 decay, transuranincs, and cosmic rays) smack into atmosphere or into solid matter, the energy of the gamma is scattered... it's dissipated a bit at a time as the gamma photon interacts with electrons or the nucleus of the impacted materials. If a gamma scatters off of an electron, some of the energy is transferred to the electron. If the electron is bumped up to a higher-energy orbital and then decays back to its ground state, the decay can cause the emission of an X-ray photon - fluorescence. This necessarily has a lower energy than the gamma, and its energy will depend on just what element was involved in the scattering. The original scattered gamma will have less energy than it did before, of course. So, the rise you see in the spectrum is probably the sum of a whole bunch of Compton scattering events which involved gammas that were originally of higher energy. From what I've read, skyglow (gammas and X-rays originating from cosmic-ray impacts on the atmosphere) is a big part of this. NORM is another big part. A few years ago I collected a box of monazite sand from a local beach. It definitely shows a thorium signature, but the peaks are nowhere near as sharp as the ones in the "quantum pendant" data. I believe this is because the thorium is diffused throughout a much larger amount of base material (I have to use a couple of pounds of it to get a good reading) and most of the decay gammas end up Compton-scattering at least once as they work their way through the sand to the sensor crystal. As a result, the sharp peaks from the original decay events are weakened, and blurred by the Compton scattering effect.
Reply by ●July 17, 20222022-07-17
dplatt@coop.radagast.org (Dave Platt) wrote:> In article <7cc8f810-1325-4542-bda7-63c76d4195a0n@googlegroups.com>, > John Miles, KE5FX <jmiles@gmail.com> wrote: >>On Saturday, July 16, 2022 at 7:16:38 AM UTC-7, Dave Platt wrote: >>> I measured one on my home-made gamma spectrometry system and got >>> a very recognizable thorium-decay signature (the isotope markers >>> are from a best-efforts calibration). >>> >>> https://www.radagast.org/~dplatt/gamma/quantum-pendant.pn >> >>Resolution of that setup looks really good -- is it written up anywhere? > > I don't think I've written up anything in detail - it's been a few > years since I played with it much. > > I have a couple of probes, both built with surplus commercial PMTs, > one with a NaI(Tl) crystal and another with a BGO crystal.How big are the crystals? -- MRM
Reply by ●July 17, 20222022-07-17
On Saturday, July 16, 2022 at 5:38:44 PM UTC-7, Dave Platt wrote:> The trickiest part was handling high pulse rates, where one pulse > starts while the CSA is still recovering from the previous one. > At some point I may sit down and try writing some DSP code to > de-convolve the CSA's pulse shaping and turn the signal back > into narrow impulses.The analog-days solution was a delay line amplifier; the long recovery tail is exponential, so a difference amplification of V(t) - (1+epsilon)V(t-s) flattens the recovery when (1+epsilon) equals the diminution of the signal during 's' seconds. The infinite-impulse response or FIR filter is relatively easy work to do that. Some good info here: <https://www.ortec-online.com/-/media/ametekortec/manuals/4/460-mnl.pdf>
Reply by ●July 17, 20222022-07-17
Thanks to Phil and John, I will soon have a PMT gamma detector to compare with the Radiacode. Hopefully, it will be more sensitive so I can be more certain of measuring Radon in the basement as well as other radiation sources. Assembling the electronics turned out to be much easier than some DIY pages describe on the web. There is a company in Israel that supplies complete Gamma Spectroscopy electronics. The company is RH-Electronics at http://rhelectronics.net I got the PIC18 MCA Module for $95.00 plus shipping at $17.95: https://www.rhelectronics.store/diy-pic18-mca-kit-for-gamma-spectroscopy Generating the high voltage for the PMT turned out to be easy. Amazon sells CCFL inverter boards very cheap. I got one for $13.46 at https://www.amazon.ca/gp/product/B07YM68GVM/ The last item is a fast high voltage diode to supply the PMT. This turned out to be the hardest problem until I found Dean Technology in Dallas, Texas, 75370 They sell a 5KV 100ns diode for a couple of bucks: https://www.deantechnology.com/products/hl500 The total price is CDN $95.00 + $17.95 + $13.46 + $2.50 = $128.91, not including the PMT that the seller refuses to sell to Canada. The US price is about $120 USD including the PMT, so nobody has any excuse for not being able to detect radon in their basement. -- MRM
Reply by ●July 17, 20222022-07-17
dplatt@coop.radagast.org (Dave Platt) wrote:> In article <XnsAED696ABEA7D1idtokenpost@88.198.57.247>, > Mike Monett <spamme@not.com> wrote: > >>On a related topic, I have been trying to find out why the background >>gamma spectrum has a sharp rise at low energies, and where does it come >>from? Do you have any ideas? > > As I understand it, you're seeing is largely Compton radiation and > X-ray fluorescence. When naturally occurring gammas (from K40 decay, > transuranincs, and cosmic rays) smack into atmosphere or into solid > matter, the energy of the gamma is scattered... it's dissipated a bit > at a time as the gamma photon interacts with electrons or the nucleus > of the impacted materials. > > If a gamma scatters off of an electron, some of the energy is > transferred to the electron. If the electron is bumped up to a > higher-energy orbital and then decays back to its ground state, the > decay can cause the emission of an X-ray photon - fluorescence. This > necessarily has a lower energy than the gamma, and its energy will > depend on just what element was involved in the scattering. The > original scattered gamma will have less energy than it did before, of > course. > > So, the rise you see in the spectrum is probably the sum of a whole > bunch of Compton scattering events which involved gammas that were > originally of higher energy. > > From what I've read, skyglow (gammas and X-rays originating from > cosmic-ray impacts on the atmosphere) is a big part of this. > NORM is another big part. > > A few years ago I collected a box of monazite sand from a local > beach. It definitely shows a thorium signature, but the peaks are > nowhere near as sharp as the ones in the "quantum pendant" data. > I believe this is because the thorium is diffused throughout a > much larger amount of base material (I have to use a couple of > pounds of it to get a good reading) and most of the decay gammas > end up Compton-scattering at least once as they work their way > through the sand to the sensor crystal. As a result, the > sharp peaks from the original decay events are weakened, and > blurred by the Compton scattering effect.A very lucid explanation. Thanks. I was able to find out what NORM is without having to ask you: "Naturally ocurring radioactive materials." I'm so proud of myself:) How big are your scintillator crystals? -- MRM
Reply by ●July 17, 20222022-07-17
On Sunday, 17 July 2022 at 20:01:52 UTC+2, Mike Monett wrote:> dpl...@coop.radagast.org (Dave Platt) wrote: > > > In article <XnsAED696ABEA...@88.198.57.247>, > > Mike Monett <spa...@not.com> wrote: > > > >>On a related topic, I have been trying to find out why the background > >>gamma spectrum has a sharp rise at low energies, and where does it come > >>from? Do you have any ideas? > > > > As I understand it, you're seeing is largely Compton radiation and > > X-ray fluorescence. When naturally occurring gammas (from K40 decay, > > transuranincs, and cosmic rays) smack into atmosphere or into solid > > matter, the energy of the gamma is scattered... it's dissipated a bit > > at a time as the gamma photon interacts with electrons or the nucleus > > of the impacted materials. > > > > If a gamma scatters off of an electron, some of the energy is > > transferred to the electron. If the electron is bumped up to a > > higher-energy orbital and then decays back to its ground state, the > > decay can cause the emission of an X-ray photon - fluorescence. This > > necessarily has a lower energy than the gamma, and its energy will > > depend on just what element was involved in the scattering. The > > original scattered gamma will have less energy than it did before, of > > course. > > > > So, the rise you see in the spectrum is probably the sum of a whole > > bunch of Compton scattering events which involved gammas that were > > originally of higher energy. > > > > From what I've read, skyglow (gammas and X-rays originating from > > cosmic-ray impacts on the atmosphere) is a big part of this. > > NORM is another big part. > > > > A few years ago I collected a box of monazite sand from a local > > beach. It definitely shows a thorium signature, but the peaks are > > nowhere near as sharp as the ones in the "quantum pendant" data. > > I believe this is because the thorium is diffused throughout a > > much larger amount of base material (I have to use a couple of > > pounds of it to get a good reading) and most of the decay gammas > > end up Compton-scattering at least once as they work their way > > through the sand to the sensor crystal. As a result, the > > sharp peaks from the original decay events are weakened, and > > blurred by the Compton scattering effect. > A very lucid explanation. Thanks. > > I was able to find out what NORM is without having to ask you: "Naturally > ocurring radioactive materials." I'm so proud of myself:) > > How big are your scintillator crystals? > > > > -- > MRMGamma Radiation is never Low Level since what matters is long-term exposure to cancerogenic Gamma Radiation so Long-term Low Level exposure turns into High Level Gamma Radiation
