Spark Detector - Alpha Radiation Detector
Hello!
1. What is this?
The detector I want to introduce to you is a simple device that allows the detection of alpha particles in the air at atmospheric pressure. It consists of two parallel electrodes: one in the form of a metal plate and the other made of thin wires. As I mentioned earlier, this type of detector is only sensitive to ? radiation, which is why it can be used as a measure of the activity of radioactive elements in this range.
2. How it works
During detector operation, high voltage (slightly below breakdown voltage) is applied to the electrodes. The active area of the detector is in close proximity to the wire electrodes. Alpha particles passing through such an area cause the formation of a sufficiently large amount of free charges for an avalanche (electric) breakdown to occur. As a result, the alpha particle in the detector leaves a trace in the form of audible and visible sparks to the naked eye.
Construction
1) HV power supply - electronic part
Necessarily regulated, giving about 4-5kV output. The current efficiency of the power supply should be large enough to be able to maintain the current resulting from a corona discharge. In the design of my power supply I used a CCFL converter (on the ~ 1kV output) on the input, which I placed an adjustable voltage stabilizer (LM317). The voltage output from the inverter is further increased by a four-stage voltage multiplier. The whole is powered by 12V. The design with a linear stabilizer is simple but terribly coarse. A fairly large 0.6A current flows through the stabilizer, so you must give a radiator. A much better idea is to use a lowering impulse stabilizer. The diodes working in the voltage multiplier cooperating with the CCFL converter should be fairly fast and withstand high back-up voltages (at least 1.5kV). I used the "GP02-20" diode.
2) Detector
When it comes to the design of the detector, the key is the thickness of the wires. They should be very thin otherwise the device will not work at all. In my construction I used tungsten wires with a diameter of ~ 0.1mm. An important factor is also the smoothness of the structure, no wire bends or scratches on the sheet. This greatly facilitates voltage regulation.
3) Pictures
4) Movies
DARK$$ wrote 96 posts with
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Comments
When you apply the source to the side (in the plane of the wires), does alpha particles have enough energy to leave a row of sparks as a trace of the passage of the particle? [Read more]
In general, that's how it should work. However, I do not know if it will succeed in the presented project. I once saw such a model in the observatory, only instead of wires there was a pile of sheets.... [Read more]
Unfortunately not. This is probably because the detector has a strong electric field and the particle is quickly "pulled" to the negative electrode. Not completely. The detector you talk about in... [Read more]
Interesting design, radiation is fascinating mainly because it is not visible ;-) Searching the web for the given password I found such a video: , isn't it a little dangerous to take such... [Read more]
I have a question: what material did you use as the source of alpha radiation? [Read more]
Are you sure they were alpha and not gamma particles? Alpha (and most bets) should stop on the first tray ... It is dangerous. Such a source taken in hand is not a special threat yet, but inside... [Read more]
On the first and second video of Americas 241, on the third TIG electrode with 2% content of Toru 232. [Read more]
Hello A very interesting idea. I have a question about where tungsten wire. Can you use 0.17mm acupuncture needles instead? And another question about the WN power supply, will the author provide the... [Read more]
And I have a question from another barrel. The whole detector looks nice and is neatly prepared, but do such discharges cause erosion of the electrodes? Will you not see the burned miniature points? [Read more]
The diameter of my tungsten wire is in the range [0.05mm, 0.10mm]. As you can see, this wire works correctly. I also checked wires with 0.25mm diameter (E1 string of an acoustic guitar) and 0.20mm (steel),... [Read more]
Hello, it looks very impressive but I would be afraid that I would move these wires and kick me :) I have a question - does this phenomenon occur in the X-ray D-08? It has an ionization chamber,... [Read more]
No - the ionization chamber is another type of detector. It is polarized with voltages of the order of several dozen - several hundred volts and measures a very small current (nano order, and even picoamps),... [Read more]
I understand that the amount of spark jumps indicates how much radiation the source gives. In the movies, the American 241 is clearly better, which sparks while TIG spent one for about 1 minute. Hence... [Read more]
He probably picked up a smoke detector. [Read more]
It's just like you wrote. As for the sample, it's like komatssu wrote. There were once such smoke detectors on the Allegro for PLN 10 ;) The radioactivity of such a sample is 1uCi. The whole... [Read more]
Interesting design, I'd like to see a diagram of this converter. Recently, I have become interested in radiation and maybe I will think about doing something like that. I advise you to check the... [Read more]
Well, I don't understand something, alpha radiation is supposedly stopped already by a piece of paper, let's say that in practice it is different and this sheet will be overcome, but how would... [Read more]
The window is - click [Read more]
Well, that's all clear, now it remains to get a smoke detector :D It is also interesting that in the description of the video to which Jarek1321 gave the link, there is information that Am241 also... [Read more]