Tag Archives: meltdown

Published In Microbe Hunter Magazine!

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WOW! I got published again in Microbe Hunter magazine!

© 2012 Natural Uranium

Autunite Uranium under long wave UV light

My samples of Uranium taken under a microscope were recently published in the September 2012 edition of Microbe Hunter magazine! Don’t forget to check out my previous published work in the same magazine, Microscopy Meets Gamma Spectroscopy – Modern Day Alchemy

Polonium 210 Gamma – Found?

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Hello,

A week or two ago I set out to detect the infamous Polonium 210 gamma ray at 803.1 keV using a NaI(Tl) scintillation detector and a mere 3.7 kBq of Po210. This isn’t too hard, or so I have been told, to do with a HPGe or using my equipment and a significantly larger activity of Polonium. The problem is that only a few gammas will be emitted, only some will actually reach the detector, and of those only a tiny fraction will be detected! But… Who am I to listen? Lol I think that I found the gamma and it stands out in the spectrum, but I thought I would go a little further. This is not a formal paper (note my informal tone). I just thought that I would post a little more than a simple message.

Polonium 210 Gammas

Polonium 210 Gammas

My Environment

I have a temperature stabilized environment with a average temperature fluctuation of 0.8 c. from the mean over a period of six hours. The detector was allowed a full day to warm up and become stable. Calibration was performed several times and with several sources, including Co60 and Cs137. Redundant calibrations were performed and tested against each other to detect any changes.

The Test

A new (less than seven days old) small circular plastic disk containing approximately (+/- 20%) 3.7 kBq of Po210 was placed directly in front of the detection crystal at a distance of 1 cm. Between the source and the crystal, a thin Pyrex glass layer was placed. The test was allowed to run for six hours and then repeated without the Po 210 source to account for background. The background was removed from the sample spectrum to produce the results.

My Findings

A scientific result which can credibly called “true”, insomuch as any result is true”, requires at least five standard deviations from the mean of a set of data to rule out likely error. Given the very low amount of data logged and the generally entropic nature of the testing setup, such an outcome is unlikely. As a result, a positive declaration of the detection of Po210 gammas using the experiment as performed is unlikely.

A set of 60 data points was taken before and after background removal. These data sets were treated as a population set from which a simple population standard deviation was calculated, for both before and after background removal. Based upon calibration of the unit, the channel numberd 832 was the most likely channel to detect the gamma in. For both the origional data and the data with background removed, the channel, 832, displayed a clearly greater than other channels near it and for the set. For the raw data, channel 832 was 3.3636861676 deviations from the mean and with the background removed, the same channel was 3.2797495046 deviations from the mean. The variance between the data with and without background was 2.56%.

Sample Gross counts
________________________________
Channel     Count          Sigmas
828          17          -0.6757272749
829          16          -0.1812926775
830          21          -0.6757272749
831          28          0.8075765174
832          39          3.2797495046
833          19          -0.1812926775
834          25          0.0659246212
835          19          -0.6757272749
836          27          1.7964457123
.
Sample – Background
________________________________
Channel          Count          Sigmas
828          0          -0.7820334787
829          2          -0.9704752808
830          0          -0.0282662703
831          6          1.2908263444
832          16          3.3636861676
833          2          -0.4051498745
834          3          0.7255009381
835          0          -0.4051498745
836          10          1.1023845423

Cesium 137 Detected in my Rain! (Radioactive Rain Detected)

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As you all know, I have always maintained that there is Fukushima fallout in the rain… but that the levels (even if they are unsafe) are too low for a Geiger counter to detect.

My sensitive Gamma Spectrometer has now (I believe) detected Cs137 in a rain water collection bucket which concentrates, or so it seems, the Cs137.

Most of the radiation detected by Geiger counters from rain is from Radon Washout, a processes whereby radon in the air (decays from natural uranium around the world) is “washed” out and falls to the ground in the rain. The decay chain is sudden and very quick, providing a few hours of potent readings before falling to background.

Inspector (regular or EXP) Sensitivity to Iodine 125:

0.02 µCi = 740Bq = 44,400Bq/60seconds
(At contact for I-125)

http://seintl.com/products/inspectorplusEXP.html

Iodine -125 Electron Capture
Gamma – 35.49 keV 6.60 %
X-Ray – 27.47 keV 75.7 %

http://ie.lbl.gov/toi/nuclide.asp?iZA=530125

Best energy range for detection by LND7317 probe:
10 keV = 100 keV (max)

The range where detector efficency falls rapidly (Cs137 is also in this range):
100 keV = 1000 keV (declining)

http://seintl.com/images/InspEnResponseC137_large.jpg

A great place to find data on isotopes:
http://ie.lbl.gov/toi/

*** Update! ****

I have calculated the activity:

My original calibrated Cs137 source (cal. vs. NIST tracible source, source ID SRS:80899-854, at 95% accuracy) was 3737 Bq.

I accounted for decay of the source:
3737*e^-((ln(2)/10979)*173) = 3696.4059560683608390980241545539265887454856828520474 Bq
=3696 Bq

For an ROI of the same size for both calibrated sample and rain water sample, I ran tests and determined counts per second:

Calibrated Source 91.2633 c/s
Rain Water Sample: 0.01439814814814814814814814814815 c/s

Now, I divided the detected calibrated sample c/s into the expected c/s to determine ratio of emission vs detection for the energies around 661.66 keV. (3696Bq * 0.851 [intensity for gamma from Ba137m])/2 = 1572.648. The division by two is because I entirely detected one side of the thin sample disk. so… 91.2633 / 1572.648 = 0.05803161292291727074335769987944

My detector is only about 5.8% efficient for such energies. (lower than my 12% “ball park by half”)

Now, merely divide the counted detection from rain by the efficiency and you have about the correct result.
(311counts/21600) /0.05803142216185694446564011781403 =

=0.01439814814814814814814814814815 / 0.05803142216185694446564011781403 = 0.24810951742643665986093914169915

Or 0.248 Bq/liter

(that is zero point two four eight Becquerels per liter)

Thoughts?

Nuclear Isotope Identification – Why Is something Radioactive?

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Radioactive materials are easy to detect with a Geiger counter, but cannot be identified with a Geiger counter. You need an isotope detector.

One of the most widely used isotope detectors is a Gamma Scintillation Spectrometer. In this video I explain how Gamma Spectrometers work. I also show you actual real-time capture of gamma spectra from several sources:
Cs-137
Cs-134
Eu-152
Am-241
Np-237
And Natural Uranium & progeny.

Please visit my website for a short explanation of the basics of radiation!

What is Radiation?

Spectrum Techniques (Where I get my sources and Spectrometry equipment)
http://SpectrumTechniques.com/ucs30_system.htm

GeigerCounters.com (Where I get my Geiger counters)
http://GeigerCounters.com

Radioactive Rain – April 21, 2012, Virginia

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I tested my rain again and found radon progeny once more.

It should be somewhat obvious by now, given the occurring, what the source of all of this.