Experience roentgenoscopy at home

At one time, I had accumulated a sufficient amount of cool, but nonetheless useless things in everyday life, one of which was the BSV-25 X-ray analysis tube.



A massive fool, with water cooling, 60kV anodic, 300 watts of dissipated power and four beryllium windows to emit radiation from each side.
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And she would have been collecting dust on the shelf for a long time, if it was not almost suicidal for me to launch it into my bright mind. As a source of anode, I decided to use the good old line transformer from my grandfather's TV set, swinging a generator on a 6p45s lamp:



At its output, we get 12-15 kV, with a frequency of 20 kHz.



Next came the question of the voltage multiplier. The fact is that this lamp with a massive anode. And it should be connected by applying a negative voltage to the cathode and ground the anode. A filament transformer must withstand a potential difference of 60 kV on the primary and secondary windings.

Naturally, the prospect of making and pouring an epoxy resin multiplier with a negative “hot end”, and even making a second generator with ferrite from the scooper, in order to throw 3-4 turns of wire on it and feed the heat, I was not at all pleased. Moreover, I did not strive to shake the lamp at full power, and therefore water cooling for the anode was not necessary.

But if you started breaking the grandfathers TVs, it is difficult to stop. And I decided to use three multipliers "un9 / 27-1.3", connecting them in series.

To be able to connect them in series, the two multipliers had to be cut with a hacksaw, finding the so-called “output A”, and through a 30kV 470Pf capacitor connected to the input of the next multiplier.



The finished structure was mounted on a piece of PCB, and all the connections and the sawn-off outlets "A" were coated with varnish in order to avoid the occurrence of corona discharges.



This multiplier allowed to receive 80-85 kV.
Next came the question of phosphor glowing in X-rays. The search led me to the chemist shop, where they sold anthracene, but alas, they sold it on kilogram packages, and since I did not plan to eat it for lunch, breakfast and dinner, this option was dropped. When I threw the call to my friends in search of a subject, one of them responded and gave me a bag of some light green substance for a bottle of beer. It seems like this phosphor covered the bottom of the oscilloscopes tube.

I made the first launch of the lamp simply by pouring an even layer in front of one of the phosphor windows, the other three windows were laid with pieces of lead, and the lamp itself stood as an anode on the linoleum. Behind put an additional casing of 1.5 mm steel, then I did not think about the reflected rays. For photo fixation I put the camera on a tripod and stretched the usb wire from it to the laptop. He himself was located behind the casing, 5 meters away with a laboratory power supply unit, with which he regulated the filament voltage (when filing regular 3V filament per lamp, the emission was too high and the voltage on the multiplier subsided almost to zero):



And it earned! On one of the pictures was clearly visible spot of the radiation beam.

Later on, I took a piece of cardboard, sprinkled a phosphor on it with a thin layer, secured it with strips of scotch tape, getting a simple screen. Having placed various objects in front of the screen, I managed to enlighten them through and get a fairly clear image on the screen.

About security

So - this is a damn dangerous thing, the radiation in the beam at a distance of 30-40 mm from the exit window reaches about 500 r / h. Despite the fact that at an anode voltage of 60 kV, this is a “soft” X-ray, and even a 2mm sheet of metal detains it almost completely, not to mention W / B floors of the house, and there is no induced radiation from X-rays, nevertheless even reflected radiation in the room is enough to spoil your health. With direct beam irradiation, you will experience joys such as acute radiation sickness and radiation burns of the arms or legs, or with what you will fall under the beam. In general, for a completely safe operation of the structure, she needs to build a sealed lead "house", and for this you need to make a normal source of negative anode voltage in order to be able to ground the anode. Or take a separate room for her, driving her from another room. Without this, operation of an installation without harm to health is not possible in principle. Since I collected it from the interest "is it possible?", Then in the future it no longer never started, and the lamp went to its place on the shelf, in the form of an exhibit of the EVP collection.

To the question of the consequences on my personal health.

The installation worked for a total of 10 minutes, the dose accumulated by me was not measured in any way (which is Fail and another gross violation of the PTB). After 20-30 minutes, as I turned it off, there was a feeling of mild nausea (something like after a heavy load on the vestibular apparatus on all kinds of “vomit-3000” carousels), which passed after a couple of hours. Three days later, the temperature rose to 37.2-37.5, and so it was held for a week, it was not possible to remove it with medication, and a week later itself passed. I started the installation a year ago and there were no more symptoms.