try self developing x-ray film instead of paper. No gamma detectors required.
-
-
try self developing x-ray film instead of paper.
except for the hypering and heat sensitivity problems...
-
magicsound Am I right that the paper you tested was 4mm far from the mica window?
If yes then putting it closer will increase the counts A LOT.
-
magicsoundAm I right that the paper you tested was 4mm far from the mica window?
If yes then putting it closer will increase the counts A LOT.
As was correctly pointed out by Robert Horst, Mica-window pancake GM detectors are very sensitive to false readings from static charge at the mica surface.
The one I use (LND7317) is expensive ($200) and the mica diaphragm is very fragile. It's also a very high impedance source, meaning the electronic amplifier connected to it is sensitive to any kind of RF that might get into the signal wires.
To protect it from both these issues, I enclosed the detector in an Al alloy box and used a piece of Al screen over the diaphragm. The detector body carries the positive high voltage, so a 1.5 mm rubber gasket is used to insulate it from the box. The thickness of the box and the gasket together create the ~4mm spacing. Thickness of the screen is negligible.
From http://physics.usask.ca/~bzulk…s251manual/alpha_2011.pdf
The range of Alpha particles in air is ~4mm at 500 keV. So IF the particles are Alphas (unknown), they would have to be very low energy to be absorbed by the air gap. EVOs on the other hand, are thought to not be readily absorbed by air, so the 4 mm gap should not be an issue.
Alphas are highly charged and would probably be blocked by the protective screen anyway. Therefore, what I might be detecting is unlikely to be Alpha particles.
Here are some images of the detector assembly, disconnected from the electronics and with the back cover removed.
-
The data files for the background and active runs are now available as zip archives:
background: https://drive.google.com/open?…OWbRdC0cMyAvuf_7QgKYjAVGv
active run: https://drive.google.com/open?…QwIkNTnAHXPPF6kbo2BXMTa3a
-
Is there higher resolution data available for the active run file? It only has one sample every 10 seconds in the region of interest.
I have edited my previous comment with a graph with an applied offset and made it clearer that it might not be 100% accurate.
-
Is there higher resolution data available for the active run file? It only has one sample every 10 seconds in the region of interest.
Nope, due to the length of the experiment, I chose the 10 second interval. So another lesson learned here - do separate high-resolution data logging for the test interval of interest.
Thanks for adjusting the graph, looks more correct now as far as causality anyway.
-
All of this seems awfully similar to how UnifiedGravity achieved their results through artificial stimulation of a lattice in tritium with a particle beam, thoughts?
-
The paper describing the theory behind it is still available here:
-
... Mica-window pancake GM detectors are very sensitive to false readings from static charge at the mica surface. ...
The one I use (LND7317) is expensive ($200) and the mica diaphragm is very fragile. It's also a very high impedance source, meaning the electronic amplifier connected to it is sensitive to any kind of RF that might get into the signal wires.
To protect it from both these issues, I enclosed the detector in an Al alloy box and used a piece of Al screen over the diaphragm.
Your box with the screen looks like it should do a good job of attenuating the effects of external electrostatic fields and EMI although it would be very difficult to put error bounds on whatever effect remains.
But there is another possible electrostatic effect pointed out by a friend of mine. Electrostatic charge collects charged radon byproducts from the environment. There is a series of papers on classroom experiments that use this technique to gather radionuclides. See this paper:
https://www.cns-snc.ca/media/u…rs/2C_nuclear_balloon.pdf
After rubbing the balloon, in just 20 minutes it collected enough to make the GM counter read 1000x background (40 -> 4000 cpm). This makes 1.6x background sound like a possible artifact of accumulation of radioactive dust over the charging period. Here is a figure from the reference above:
-
This graph shows rad counts from all working sensors in the file. 30 samples here is about equivalent to the 300 samples CPM calculation in the live stream.
180 samples = 30 minutes CPM. The radiation testing period becomes visible even in the snapshot of the entire run.
I'm not sure why, a closeup shows that there's an offset between the reported times and the elevated radiaton events. It doesn't seem to be due to the CPM calculation I'm doing. Anyway, more of interest is that there seems to be a correlation with what is called "CounterK". Other data has been omitted for clarity, but no similar increase seemed present there at first sight.
There's also some weirdness in the timestamps. The timezone isn't UTC. I had to apply a 1-hour offset to the radiation testing times.
-
can
The time zone for the lab computer was set to CET for some reason in the past, and not noticed until the test had started.Rather than change it mid-stream I left it for the entire run.
Following suggestions made earlier, I did a null run, using a new sheet of printer paper straight from the package.
The data file is at https://drive.google.com/open?…6nnnF6WHfxEAJq7-3vjPmZVDM
and the event log file is at https://drive.google.com/open?…BlhWjQtuqlP5CBPHGy0NSUnxj
I expect some raised eyebrows!
-
60 samples and 300 samples CPM. This time the data had a 1Hz sampling rate:
-
It is possible that there are more particles types. So by shielding one type it could reduce count rate noticeable.
From my experience there is direct relation between Pancake distance and activated material with respect to counts. Yes, I can also measure them from around 1cm distance but putting it closer is really big difference. The best result is in a direct contact.
But in case of ZnS(Ag) Alpha detector distance is not that important. There the detector has protective mesh as well in a similar distance.
And as described earlier increased counts are detected even with range of 2m from the cell. But these are not normal Alphas.
So to surmise it I am convinced there are at least 3 kinds of radiation:
- Alpha
- Beta
- unknown
Each is behaving little bit differently.
-
@JohnyFive
Could you make a graph of radiaton CPM versus distance? If there are different types of particles being emitted or particles decaying to other particles there might not be an inverse square law dependence with distance.
-
Here is the SEM/EDX report from the very first run Titanium Sponge, D2O, LiOD, Nickel. You can make your conclusions.
-
For those not understanding EDX fully, there is plenty of Lithium/LiOD around. These are the crystals all around the Sponge.
EDX has limitation that it can't sense Li and lighter elements, so it is just missing there.
-
Here is the SEM/EDX report from the very first run Titanium Sponge, D2O, LiOD, Nickel. You can make your conclusions.
Was this EDS from the LiOD only?
You should enable cadmium, chromium!
The data shows a lot of carbon because our air is full of CO2 that goes into solution in water forming CO3H- + p+ and in deep PH CO3-2. This already points to the limits of such an open dish experiment. Dust --> silicon is also seen and no interesting elements measured except once Vanadium, that can be expected from Ti.
I would try to get a good spectrum if the sheet once delivers 3-5 x background. 320keV, 749keV for Vanadium could be interesting.
-
Yes, there can be contamination with Carbon as it is happening anywhere in the air.
During analysis peaks from Cadmium, Chromium can overlap with other peaks and create false results. This was avoided during measurement.
The sheet always delivers around 5x background with Ag foil. But as I said many times, there are no emitted Gammas. This mean that Gamma scintillation detector is useless.
-
By the way there are traces of Palladium deep in the Sponge. But they are barely detectable. Peaks are visible but not identified.
