Tag Archives: lepton

Japanese Air Filter Test Results

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Recently, a friend of mine sent me a series of samples from Japan. He, my friend, lives in Japan and obtained these samples at some personal risk. I have started the process of testing each of the many samples using gamma spectroscopy and other techniques. I will be posting my results for each sample as I test them, which may take time given my busy work schedule.

Sample J-F is an air filter from an apartment AC/heater (shown below).
J-F Sample in original bag from Japan. Note the "Hello Kitty" on the bag.

As you can see, the analysis did detect a possible 85 Krypton contaminant, as well as other curious spikes. Please take a look and see what information you can detect from this spectrum and the accompanying data.

AC/Heater Paper Filter Sample J-F From Saga City, Saga Prefecture

AC/Heater Paper Filter Sample J-F From Saga City, Saga Prefecture

Full Report – Edited for public release
Spectrum Peak Report
Spectrum Data Report

Japanese Soil Tests – First Results

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Soil Sample J-A From Kashiwa City, Chiba Prefecture (26km NE from Tokyo)

Soil Sample J-A From Kashiwa City, Chiba Prefecture (26km NE from Tokyo)

[NOTE: This is not my official results, but a merely my first test of the materials. Much more to come]

I have just received a set of samples from a friend in Japan. The samples are from various locations around the country and ready to be tested in my gamma spectrometer. I will be publishing a full set of tests very soon, but until that time I thought I might provide a small glimpse of the preliminary results. This is a gamma spectrum from a sample, J-A_3600s, which was tested for one full hour using gamma spectroscopy. The sample shown came in a small 1” x 2” canister and contained soil from just under a water rain spout in residential housing area (back yard), of a person living in Kashiwa City, Chiba Prefecture (26km NE from Tokyo).

The sample measured about 306 CPM at contact using a 2” pancake Geiger Muller probe. During the hour of testing, clear photo-peaks for Cesium 134 and 137 were easily detected from the sample. Other features included several very small deformations in the spectrum which were either inconsequential, i.e. x-ray interference, or unidentifiable due to extremely low activity.

The extreme amounts of background “noise” found in the spectrum is consistent with a powerful beta emitter. Gamma spectroscopy cannot directly detect Strontium 90, but given the release amounts of Cs 137 and the typical matching of Cs137 and Sr90 isotopes following a nuclear release, like that of Fukushima, it is plausible to consider that Sr90, and by decay association Y90 and Y90m, are also present.

Alpha Radiation, Geiger Counters 101 Part Two

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Alpha radiation was first detected in the late 19th century by Ernest Rutherford. Alpha radiation is the release of two protons and two neutrons with many millions of electron volts of kinetic energy! Alpha radiation is very positivity charged and cannot readily move more than a few centimeters from a source before tuning into normal helium. As a result, alpha radiation is only dangerous when inhaled, ingested, or otherwise allowed into the body.

Three more videos are coming!
Beta Radiation, Geiger Counters 101 Part Three
Gamma and X-Ray Radiation, Geiger Counters 101 Part Four
Radiation Math, Geiger Counters 101 Part Five

Important Websites:

Radioactive Units – Do Not Use Them Incorrectly!

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Geiger counters count ionizing radiation events.

To measure a detected reading, the energy of the detected radiation must be known. If the detected radiation has an unknown energy, there can be no measure, but merely the detection.

Examples of different energies from common isotopes released by Fukushima (approx):
Cs137 — 0.5 MeV beta
Cs137 — 1.1 MeV beta
Cs137 –Ba137m — 0.6 MeV gamma (often used to calibrate GM’s)
Sr90 — 0.5 MeV beta + weak gamma
I131 — 333 KeV beta
I131 — 606 KeV beta
U238 — 4MeV alpha

As you can see, the energies very quit allot and cannot be assumed.

Here are some energy dependent units:
1 Gray = 1 joule / 1kg
1 Seivert = 1Gy x RadiationFactor x BodyPartFactor
1 RAD = 0.01 joule / 1kg
1 REM = 1 Rad x RadiationFactor
1 Roentgen = = 2.58×10^-4 Coulomb / 1kg

As you can see… each of these units uses a degree of energy. You do not know the energy unless you know the exact nature of your source. As a result, you cannot use them.

In short: If and only if you know the exact energy of your source and a specific calibration and calibrated geometry, you cannot accurately use any energy dependent unit. All such unit measures are meaningless in these cases.

Use Counts Per Minute (CPM) or Counts Per Second (CPS)

Have fun!

New Radioactive Depression Glass Peice!

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I bought both of these peices at a local store in my town for under $20 each!

Depression Glassware, Vaseline Glassware, and other interesting glassware from the early to mid twentieth century where coated with, glazed with, or contained Uranium Oxide as a colorant. The Uranium Oxide created a brilliant green color, and could be mixed with other chemicals to make other powerful and rich colorings.

Depression, Uranium containing, glassware is generally safe to handle. Remember to keep it away from children and do not store it in a room where people frequent. Keeping it a few feet away from most people in an under-used room is often safe. Tip: Use a blacklight hidden behind the glass to make it look beautiful!

Uranium Oxide is mostly fertile U-238, sometimes with a tiny touch of fissile U-235, which is naturally occurring. The radioactive decay mode is an alpha particle with about 4.26 million electron voltes of energy! The alpha travels but a few inches from the object before gaining electrons and possibly releasing additional radiation through secondary ionization. The secondary decay is a gamma ray at about 49.55 kilo-electron volts. In reality, the full decay series and total emission band is much more complex.