I remember when I was a TV repairman back in the late 60's and early 70's, there was a scare about x-rays coming from color TV sets. It was true. They mostly came from tubes called the high voltage rectifier and regulator. It had 25,000 volts across it. The tubes were types 3A3, 6BK4, 6EL4 and others. GE even came out with a regulator tube that had a lead-plastic coating to block x-rays. Other makers issued retrofits that included a shield to install in the set.
röntgen of this spectrum is negligible. I have a 60Kv dentist x-ray tube the radiation can already be stop with an iron plate at 100Kv tube there is radiation to be worrying.
rationalguy Being a TV repairman you might know the answer to this: how much current does a flyback trans output at the suction cup connection? I know it's upwards of 20kv but wondering if there's enough current to kill or do serious harm.
FUCK!!! I was wanting to see a tube or have a tube forever. Just was given a CRT tv old as dirt. Is a Magnavox but I don't want to take it apart as it is not mine. Especially if the tubes are shielded.
All the TVs I repaired had the high voltage rectifier tubes inside a cage, that resembled the perforated metal in a microwave oven door. The screens were leaded glass to block radiation from the electron guns. They were rated for 40,000 volts, 1 mA peak current. the filaments were supplied by a 3 turn winding right on the flyback transformer. The flyback was driven by a 6CD7 or EL509.
The old colour TV rectifier tubes might be better - built for 23 kv. And while you are at it, you could get about a milliamp at 25 kv from the flyback of an old colour TV. The rectifier tubes on the old TVs was always in a metal cage for xray shielding. Trouble is, where to find that 1975 or earlier 23" colour TV.
Every video of his I watch, I have to ask myself "Why doesn't this channel have more views?". He seriously deserves more credit for some of his videos.
Fun experiment. True X-Ray tube elements are in close proximity to each other and the tubes utilize a very very high vacuum to prevent arcs. The filament or cathode, depending on the type of tube, produce electrons that are directed and focused on a target. The target gets excited and produces X-Rays that are aimed toward a window to the outside world.
@3:10 you can actually have an arc in a vacuum, and not just over a surface. It is actually one of the difficulties that needs to be addressed when designing a high voltage vacuum circuit breaker. Even at low temperatures there is a 'cloud' of electrons above any metal surface in a vacuum. A high enough voltage between two metal plates will accelerate those electrons over the gap. If there is sufficient current available the electrons will heat up the surface of the anode to the point where ions are ejected from the surface and accelerated towards the cathode heating that up and increasing the current further. Now you have an actual arc with ions flowing in one direction and electrons in the opposite. This starts an avalanche which is limited only by the current that the power supply can provide and will continue until either the power is turned off or the electrodes vaporise to destruction.
The reason you didn't see any fluorescence on the intensifying screen is that those screens were optimized to respond to "diagnostic" x-rays, typically, those produced from 50KV to 150KV, sometimes described as "hard" xray. Anything less, those screens do not respond. Now if you could find a "Mammography" cassette, you might see some fluorescence. For technical reasons, Mammographic x-ray machines operate in the 19KV-50KV range, sometimes described as "soft" x-ray. Nice set-up, I am totally jealous of your HV power supply!
yes, I have the same gieger counter and it's shit around high voltage. It completely breaks down if it's placed near a running NST or van-de-graff generator.
Yeah I had one that acts like that. EMI sensitivity depends to how you connect the counter circuit. Original Russian datasheet has the diagram with the preferred (less EMI sensitive) way to use those tubes, with the outer part of the tube grounded and the pulses read from the inner wire electrode using a small de-coupling capacitor (10pF). But it is very common to sense pulses from the outer electrode instead, and that picks up EMI.
well, he took it in his hands, which is surely enough to negate the E-fields, and i think HV DOES trigger Gieger counter 'cause it accelerates electrons so much that they blast atoms' inner electrons away and produce high energy radiation, specially static electricity, because of strong local E-fields. we shouldn't underestimate HV, just look at this crazy stuff: en.wikipedia.org/wiki/Terrestrial_gamma-ray_flash
Nice! I bought a X-Ray tube from United Nuclear with a 25kV power supply. It's generating X-Rays! I checked it with an EMF detector and got background, so no interference! I placed my camera close to the tube, turned it on, and I got beautiful scintillations flashing in the video from the X-Rays striking the lens. Makes it look grainy. My Geiger counter goes nuts if I'm fairly close, and it will peg out the meter. I get noticeable increase in counts/minute from across the room. I plan on doing other tubes. Thanks!
To tell if it is really x rays, take a sheet of lead or even steel and slide it between the tube and the counter. If it is spike interference, the counter will still click away. If it is X rays, the counter will stop counting, or reduce count drastically since the low voltage X rays don't penetrate the lead. Fluorescent screen, you will not be able to see glow with your eyes until the dose rate is in the hundreds of MR per hour, a very high rate and not possible with your power supply current.
The geiger counter is a Mighty Ohm kit. Search the web for mightyohm. Glass can be coated with ITO to form a conductive layer. This process typically requires a vacuum chamber or sputtering setup -- probably much more expensive than buying glass already ITO-coated. Still, it might make for an interesting video.
I see the video is already so old, wow good run! I´m enjoying your videos! Anyways I´d like to add that it IS possible to arc even in a perfect vacuum. The ions can be ripped off the cathode material creating a conductive path. Works in micro plasma thrusters. I had one tested in UHV. However, you need like 10x the voltage of same gap in air.
Hi' id realy love to see inside your high voltage transformer there, would you please make a video of the top plate removed as id love to see what the transformer looks like, and if its in a poxy or a dry ferrite transformer with apoxy around it " like a flyback transformer from a crt tv, Many thanks for sharing, ☆☆☆☆☆THUMBS UP☆☆☆☆☆
I did something like that with an old slightly gassy 6JE6. Ran one end of a 12Kv neon sign transformer to the plate cap. Yeah, just like that, the tube glowed blue, but the getter deposit had a ring of green light coming from around it. I shut it off!
so it takes 30kv in the uA range to produce x rays !!! so if you use say 25kv them the peak V could easily make 30 plus KV meaning x rays are easily possible and quite likely .well im glad i got a Dosimeter .more people should be watching this as they think there safe and in reality there not as safe as theylike to make out .great video ,John
Its like me unique LOL I'm shit @ that kinda stuff .Never have been good like that ,but I do have other good quality's I just haven't found them yet ;)
HighVoltageProjects: "so it takes 30kv in the uA range to produce x rays !!! so if you use say 25kv" ==25 kV will produce x-rays. A lot of tvs use 25 or 26 kV. Even small TVs that use 15 kV produce it and they all have a metal shielding in the back. The glass contains strontium so that it also acts as a absorber for X-rays.
I get that feeling too, to be honest, since the phosphorous didn't fluoresce. I'm a chemistry student, and we have to wear radiation badges in the medical department and in the lab while preparing radioisotopes for injection into patients;[18F]FDG mostly; we use a machine but still have to handle it Also, I've seen duct tape produce x-rays when pulled apart. O.o Still, you can be denied a flight if you go over your annual limit, so it might be a good idea to get a radiation badge regardless
Ohhh god bless you for feeling things and being honest and god bless you for injecting people with radioisotopes and god bless isotopes and ionizing raditation and god bless god for making things decay and god bless chemistry because without chemistry how would we understand neurons or charge gradients and god bless x-rays and cats who eat hair
I used to do this with dud horizontal output tubes (e.g. 6JE6C, etc.) using a 12 kV neon sign transformer (so that's about 17 kV peak). Oddly, it was the getter patch on the glass where the x-rays were emitting, a nice ring of green glow around the patch. Actually it breaks my heart to see a perfectly good 811 being abused like that but I guess old burned out tubes are not as common as they once were.
Could X rays be created using a camera flash capacitor connected to the vacuum tube creating a short burst of X rays? Would such a capacitor deliver enough voltage?
ebay sells tiny china step up devices that claim 40kv, i didnt take these claims seriously until i found that i could make 1cm arcing with only a tiny single aa battery as input to the thing..
yes its bought from ebay, great tiny device, I loved it very much, value for money, be sure not to overload it and don't let it run without allowing the other end to discharge, it can ruin the module easily as well
You could easily be producing 10,000 volts with your rig, just not much current. Even the magneto of a lawn mower engine can produce that high of voltage.
I think the geiger is reacting to EMF high voltage, not to the x-rays. ( its happen with fluorescent lamp and reactors and stuff too). its a metal geiger normally it will react to gama, or interference from near EMF.
A true geiger counter is actually trying to measure particles, like radioactive decay. X-ray is actually a very high spectrum of light, I don't even think a geiger counter would even respond to X-ray radiation. it needs either beta or gamma.
Not true, gamma is also a very high spectrum of light, just a tier above x rays. I have a geiger coutner and it picks up x rays gamma alpha and beta, only alpha nad beta are particles
At such low kV the spectrum of x-ray is gonna be very soft- not surprising barely a single photon is getting to you. I'd be really curious how many µGy is hitting the intensifier- I've shot CR cassettes and it takes probably more like 1000µGy to get a good visible-to-eye glow. I'm really interested to test a GdOS and CsI scintillator but unfortunately they are sandwhiched to TFT so I've not been able to get a straight sample to try. I have an interesting story about the company who made your intensifier
Hobbyist x-ray trivia: soft (tens KeV) x-rays barely penetrate common GM tubes. Try alpha-window tube, then your counter will roar even when held feet away. Rather than Intensifier, try Zinc Sulfide paint on black paper, then put the x-ray source behind the paper. Dark-adapted eyes will see some flashes and glows. Good source of large amt of ZnS is Speedball Night-glow fabric paint from art supply stores for around $15. Safety: compare to solar UV of similar photons/sec rate: insignificant!
Arcs in a vacuum are possible. They are not like conventional arcs though, they are called vacuum arcs and are basically just hot spots that form on the electrodes and lead to more current flow.
Medical X-Ray tubes rotate the anode at high speeds to lessen buildup, accumulation of deposits, distribute heat buildup and increase the service life of the tube.
I doubt anyone is going to read this and really understand it, but the "x rays" shown in the video is just RFI from the arcing inside the tube. You have to be upwards of 90kv to get xrays. I was reliably able to generate xrays in my home lab, but it wasn't near as easy as hitting an old tube with 15kv. I used 120kv and an old mercury puddle rectifier that I modified with a hot cathode and a tungsten plate. Not saying ANY xrays would be generated using your method, but it is an ultra minute amount with no energy.
Monel Funkawitz That is inaccurate; x-rays can indeed be produced with as little as 15 kV and using certain receiver tubes. I have used the method to usefully expose polaroid film without any phosphorescent material. It is weak, but present nevertheless.
If it isn't glowing green, it isn't producing. Not blue... green. If you are trying to light phosphorus, you really gotta nail it. To cold cathode, you need a functioning anticathode, and your target inside the tube needs to be dished to focus the xrays. You gotta hit it hard if you want high energy xrays. I had mine to the point where I could develop film with a chicken wing as a finger analog in a 2 second burst. Figured I better quit before I screwed up and triggered the remote with me in close proximity and got blasted. My tube had a green glow to it and I had to water cool the target. A lot of work, but it did work. I tried tubes, bulbs.. everything, but could not get xrays without a heated cathode, and could not get high energy xrays unless I got close to 100kv. You could tell on the electric bill when I was playing... lol.
I was using OLD 6BK5 tubes (thin light glass bulb). Very slight voltage applied to the cathode heater; just enough to eject some electrons, but not so much that would load the HV power supply below 15 kV or so. And yes, a green glow was noted, in addition to a permanent discoloration (brown) of the glass. Cool stuff.
Emi/rfi. Put the Geiger in a completely sealed and grounded metal box and see if it triggers or wrap completely in aluminum foil that is grounded. Xrays will penetrate that AL no problem. If you start into the dark path of ionizing radiation, make sure you KNOW what you are doing and have redundant safeguards in place. I had a friend learn the hard way that just because the detecting equipment isn't working right, doesn't mean the danger is not there. You can get a fatal or cancer causing dose way before you feel it.
are you sure your x-ray detector is detecting x-rays in your setup? am asking because you had it very close to your tube. it might simply be influenced by the strong electrostatic field your were applying to the tube. there are several ways to test this. one of wich is applying the inverse square law. good luck
+Amira Lozse Good thinking! But look how every beep occurs consistently with every current peak in the amp meter of the power suply. When current flows, the amp meter detects it and that current are the electrons hitting the other electrode and producing the radiation. I don't know if i'm missing something here. Maybe the magnetic field of the electrons is influencing the readings of the metter but the current is so low I don't know if this is possible.
I am using 1J29B subminiature tubes that have a 1.2v filament voltage in guitar effects distortion pedals as a diode for clipping to make distortion. Because of the low filament voltage of 1.2v these and a few others work great. Recently I purchased 100 Sylvania 5642 tubes for $20.00. But their is a warning about possible Xray dangers. From what I can gather this is only at the high voltages like 25kv. I am only running at up to 1.2 usually. I am experimenting with overvolting the the 1J29B tubes at up to 5 volts. Want to do the same with the 5642. Am I correct in believing the 5642 is safe at low voltage of 1 to 5 volts?
I remember hearing a theory that the "electrons" travelling between electrodes in a tube are actually composed of mostly Beta radiation. This seems to make sense, since beta is easily directly convertible to electrical energy, and apparently would produce a characteristic glass decomposition reaction usually seen on tubes that have been in operation for a long time.
Thanks for the info :) About the conductive glass: I don't need conductive glass in particulair, I need something that is see-trough and conducts electricity. Maybe some sort of plastic, or a thin layer of metal deposited on a surface (maybe even graphene)? I was thinking of metal nanoparticles in water, and then evaporate the water so only the metal would remain. I find $30 for a sheet of 10x10cm a bit to mutch for a school project, and I will be needing quite some glass. Thanks for your time
he changes his studies often and will probably only do this for a couple days or less. at this rate he will not be subject to much if not any. im sorta like him but for weeks on end i was subject to my small amounts of radiation created in a similar way. it did not case any problems at all just sum head akes from ozone. but nothing from xrays. and i do have to say you have a very very cool job / internship.
I used 811A's in many Tesla Coils, but those were running at 1200 VDC plate voltage. You're 10 times that. I would really hate to see a video that showed X-rays coming off an 811A at its usual operating voltage! Thanks for a very interesting video... -- Dave
Flip the screen over and take a long exposure photograph of it. Also, you should up the voltage quite a bit, at 20keV the photons don't penetrate all that well. Then there's nothing stopping you from making radiograms :)
I am currently doing a similar project. I am looking at using a General Electric GL 8020 tube. Unfortunately, I do not have a HV power supply, so I was going to make one using an emco dx250. Good thing raw lead isn't that expensive :)
Actually ice makes x-rays as well, comets and glaciers are natural sources. Not too sure the mechanics but happens when it fractures from thermal expansion stress
"A new MIT study suggests you could go 400 times higher than average background levels and you’d still not suffer very much genetic damage. The current limit for evacuation procedures is only 8 times background radiation Then I read studies suggesting even the tiniest radiation exposure can cause gene toxicity And I've seen studies claim low dose radiation can even be good for you So it seems there is no correct standard. It varies by person. Your genetic makeup most likely determines the risk" ==There is no reply button for some reason. Apparently, there was a study on rats and since our physiology is close to them, it stands to reason that it applies to us as well. It is rather counter intuitive. The problem I see with radiation is that the damage it does is random. You might get a tumor because of 1 single mutation and you might not. Some people in Germany go and sit in old uranium mines, in sofas to get their radiation dose.
Vrej Egon Spengler One DSB can't in itself cause cancer. You receive more in a month from aerobic metabolism than a lethal dose of radiation, but it gets repaired.
Vrej Egon Spengler "...not suffer very much gene damage." Very much?? Well, it takes only a single mutation to cause cancer. Marie Curie died after her radiation exposure. So we all die, but why are you wanting to speed it up??
Those are probably soft x-rays. However, don't expose yourself, you know it's a cumulative thing. If I were you, I'd take a lead sheet and make a shield for my family jewels. Sort of like a cup or something, encased in a plastic wrap, to put in my shorts. If you plan to make more energetic rays or do this more often, I'd recommend a large surface lead shield behind which you can hide efficiently. Experiments are great, but if you damage your health, nothing is fun anymore.
It is possible to have a spark in a vacuum, at high voltage you will have a electron cloud around the negative electrode (well that might not be a TRUE vacuum if there are particles like electrons in it, but hey...) And if the tension is high enough (or electrodes close enough) you will have a spark even in vacuum.
I was just reading about x-ray tubes today. I didn't realize how inefficient they are. Apparently only around 1% of the total power is actually converted to x-rays. The rest just turns into heat on the anode where the electrons are hitting it. Seems like more efficient tubes would be a good area for research.
Frankly not really, few people want to buy such tubes and even fewer can [legally] buy them, the market for xray tubes is small, and people that buy them tend to have a budget high enough that energy efficiency is not an issue. It would only make sense if they became common household items, like a kit to do xray scans on yourself, but stupid regulations would never allow such a thing to be sold
i think the giger counter is just picking up stray electrons from the high voltage itself.(interference) im 90% sure thats what is happening and the pannel only glows because of the reflection of light emitted from plasma. this should be emitting xrays but a very very almost undetectable amount as you just made a plasma ball in an impurfict vacuum. being able to heat the filament ant a high voltage potential would make much more xrays
Wonder if you could make a vacuum tube without a tungsten filament, replace it with a uv led since uv has enough energy to move electrons, perhaps use a material in which when uv light hits it it throws off more "free electrons" Would drastically reduce power demands and heat issues, also could open up different drive characteristics since also the led could also be digitally controlled or even pulsed at different frequencies or even intensity
try using a large clear filament type light bulb instead of a tube. I've had some spectacular discharges just using an Old Ford coil with the secondary lead firing into the solder buttom on the end of the bulb. Don't use the coil ground either just let it shoot out the ends of the filaments. 350-500 watt old filament bulbs are great for this, if you can still find them? Cheap too.
I tried to feed high voltage to a vacuum tube, I can only get around 10-20 microsievert per hour, and it is not intense enough to light up the intensifier screen with 400 gain. I am using 10kV as well but mine current might be too low. I will try to increase the voltage and current to see if I can get more x ray. I also tried to heat up the filament then apply the high voltage, but I don't know why somehow the filament is burned.
Well, changing the length of the tube isn't going to make the electrons more energetic, it will just take a higher voltage to get them moving. (remember eV is a measure of energy)
I know that, perhaps I should've been more accurate about my idea: Salty water is still see-through. If you have to look through it in a horizontal direction, you could use some sort of a small fish tank with electrodes on opposite sides.
I've heard recently that geiger counters have a lower limit one what x-rays they can detect - I see geiger counters on the internet claiming minimum energies of 10keV, 40keV.... (I don't know whether that's just the case blocking them, or something fundamental about the mechanism of geiger counters.) You started getting a reading at 15kV, how do you know it wasn't blasting out 9keV x-rays well before that? (Kinda spooky.) In general, even - how would one tell if you're being irradiated by low energy x-rays?
A bit late, but with every discharge happening inside the tube there is a loss of vacuum due to outgassing and I would expect the glass is lead glass as its an easy glass to work with over soda lime. Lead glass is about 20% lead although it varies. Being lead this would block the small amount of x rays produced.
You really need to get up to 50KV before you start to produce any x-rays energenic enough to penatrate the glass and metal inside the valve. Most flouroscopy is done around 3 => 8mA. Plus there's the inverse square law with any radiation, visable or not. And intensifying screens don't light up that much even if they are in the primary beam. You need the very old ones that were used for short exposures or an old flouro plate. Great video with your limited resources. Oh, one more thing X-Ray tubes are about 1% effecient. 99% of the energy is turned into heat. (That's why the anodes spin) The noise you hear during a X-Ray.
when I look at this and how long it's on , what voltage it is , what tube it is , and how far he is and u compare it to a dental xray or something im pretty sure this is moderatly safe.
You should search for Grenz Radiation, used in dermatology for treating certain disorders. Also a x-ray therapy in Austria that I heard of uses 13kV to treat some skin disorders. You need a beryllium window to enable these low energy particles to escape.
@@fidelcatsro6948 that's incorrect, even old CRT monitors/tv's did emit a tiny bit of X-Rays, while those operate anywhere between 17kV to 30kV (depends on the size). the reason crt's had such little x-ray output though is because, well, the glass is REALLY thick.
@@fidelcatsro6948 no, the tube needs to have a vacuum, people even achieved x-rays with properly sealed glass capacitors (it needs a very deep vacuum, which old CRT's also did have) so a. your tube needs to have a deep enough vacuum b. your source must be powerful enough, so it's not only about having 15kV but enough (m)A current too. c. i'm sure tesla coil's don't have a powerful enough current output AND i think, this is where I could be mistaken, but i think you need a proper closed circuit (like one wire at one end of the transformer's coil and one wire at the other end) maybe it IS possible if you hook 1 end of a tube up to ground and the other end close to the tesla coil, but as i said i don't think thats powerful enough as it's not just about the volts but no in OPEN AIR it's not possible so that's all safe
Well, probably not that much radiation there I think, since you're only operating it at 20000 volts and not for very long. Also, the glass doesn't let much radiation through. Not at these low energies anyway. X-ray tubes are generally made with a window where the glass is quite thin. However, playing with radiation is always a dangerous thing to do.
nice explanation but were you using the cathode tube as a spark gap device enclosed in vacuum? i try a lot of experimentation with ignition coils and buzzing switches to run them on open spark gaps, am i exposing myself to xrays?
Sorry, a quick wiki shows it was simply radiation that killed her. "from aplastic anemia believed to have been contracted from her long-term exposure to radiation."
Hi Ben, I am not convinced that what you measure is X-ray. My Inspector GM counter indicated a high reading, 20 µSv/hr, when placed at a distance of 10 cm from a sparkgap Tesla coil. When I replaced the GM counter with a scintillator, I measured only background. Besides, a GM counter is very insensitive to low energy X-ray (below 40 keV). I believe that what you measure is due to the electric field your tube generates, which disturbs the GM tube. See my channel,newest video. Regards, Alfred
my high school shop teacher bet me I could not do this.... then almost kicked me out of school when I proved him wrong..... just like this! But he did give me the A he promised.
20KV X-rays are too "soft" to get through the glass. Why should the tube arc over? The enode connection is on the opposite end. Maybe you should short all the pins on the bottom together. Another thing: all X-ray tubes, after a long period of non-use, need to be "cleaned up" by slowly increasing voltage, and waiting for residual gasses to be sputtered away.
You implied that the geiger counter test was the answer to Xxdixon79xX's question, which it's not, hence my comment. That being said, I would still call this safe.
The voltage he's using is very very low, in medicine we use at least 45 kV and even then it barely registers on our dosimeters (a little cassette thing we use to measure how much radiation exposure we've had).
I also did some experiments. (statute of limitations: more than 7 years ago!!!) with pulse tubes including 5642, DAC32 and others. Interestingly I *did* get my intensifier screen to light up an RFID tag through a Maplin project box though the only casualties were my phone and a memory card or 3 that got nuked while experimenting which also damaged the onboard camera. I can assure you that my dose was minimal based on multiple redundant dosimeters with two different tube designs and lead sheeting. Not sure why but did also find that putting the tube under oil did not help much as it still failed. Perhaps worth investigating? The module I used for this experiment was intended for lighting gas on a large industrial boiler so designed for high reliability: the smaller potted transformers sold in handheld lighters aren't quite enough though are useful for a different project like powering a Gen 0 13.5KV NV tube.
You can buy it on ebay, or try to make it yourself. but if you just want for detection you can use any video camera, it will show "snow" if exposed to X rays.
I remember when I was a TV repairman back in the late 60's and early 70's, there was a scare about x-rays coming from color TV sets. It was true. They mostly came from tubes called the high voltage rectifier and regulator. It had 25,000 volts across it. The tubes were types 3A3, 6BK4, 6EL4 and others. GE even came out with a regulator tube that had a lead-plastic coating to block x-rays. Other makers issued retrofits that included a shield to install in the set.
röntgen of this spectrum is negligible. I have a 60Kv dentist x-ray tube the radiation can already be stop with an iron plate at 100Kv tube there is radiation to be worrying.
rationalguy Being a TV repairman you might know the answer to this: how much current does a flyback trans output at the suction cup connection? I know it's upwards of 20kv but wondering if there's enough current to kill or do serious harm.
FUCK!!! I was wanting to see a tube or have a tube forever. Just was given a CRT tv old as dirt. Is a Magnavox but I don't want to take it apart as it is not mine. Especially if the tubes are shielded.
How old is "old as dirt" here?
All the TVs I repaired had the high voltage rectifier tubes inside a cage, that resembled the perforated metal in a microwave oven door. The screens were leaded glass to block radiation from the electron guns. They were rated for 40,000 volts, 1 mA peak current. the filaments were supplied by a 3 turn winding right on the flyback transformer. The flyback was driven by a 6CD7 or EL509.
The old colour TV rectifier tubes might be better - built for 23 kv. And while you are at it, you could get about a milliamp at 25 kv from the flyback of an old colour TV. The rectifier tubes on the old TVs was always in a metal cage for xray shielding. Trouble is, where to find that 1975 or earlier 23" colour TV.
I have a couple of those tubes.
@@RC-nq7mg Me too. I have one that even says "warning x-rays" on it.
@@VaionkoMOST of them had that warning on them
Every video of his I watch, I have to ask myself "Why doesn't this channel have more views?". He seriously deserves more credit for some of his videos.
Wish granted I guess
Fun experiment. True X-Ray tube elements are in close proximity to each other and the tubes utilize a very very high vacuum to prevent arcs. The filament or cathode, depending on the type of tube, produce electrons that are directed and focused on a target. The target gets excited and produces X-Rays that are aimed toward a window to the outside world.
They are usually separated pretty far
@3:10 you can actually have an arc in a vacuum, and not just over a surface. It is actually one of the difficulties that needs to be addressed when designing a high voltage vacuum circuit breaker.
Even at low temperatures there is a 'cloud' of electrons above any metal surface in a vacuum. A high enough voltage between two metal plates will accelerate those electrons over the gap. If there is sufficient current available the electrons will heat up the surface of the anode to the point where ions are ejected from the surface and accelerated towards the cathode heating that up and increasing the current further. Now you have an actual arc with ions flowing in one direction and electrons in the opposite. This starts an avalanche which is limited only by the current that the power supply can provide and will continue until either the power is turned off or the electrodes vaporise to destruction.
Same basic principle that a VFD/Vaccum Florescent Display works, crank up the voltage and they will arc.
The reason you didn't see any fluorescence on the intensifying screen is that those screens were optimized to respond to "diagnostic" x-rays, typically, those produced from 50KV to 150KV, sometimes described as "hard" xray. Anything less, those screens do not respond. Now if you could find a "Mammography" cassette, you might see some fluorescence. For technical reasons, Mammographic x-ray machines operate in the 19KV-50KV range, sometimes described as "soft" x-ray.
Nice set-up, I am totally jealous of your HV power supply!
Are you sure your Geiger counter is not being confused by the 20.000V volt electric field :)
Yes but we-re not so sure at what point we're supposed to laugh at this "joke".
yes, I have the same gieger counter and it's shit around high voltage. It completely breaks down if it's placed near a running NST or van-de-graff generator.
Well, the glass gave off the typical x-ray glow
Yeah I had one that acts like that. EMI sensitivity depends to how you connect the counter circuit. Original Russian datasheet has the diagram with the preferred (less EMI sensitive) way to use those tubes, with the outer part of the tube grounded and the pulses read from the inner wire electrode using a small de-coupling capacitor (10pF). But it is very common to sense pulses from the outer electrode instead, and that picks up EMI.
well, he took it in his hands, which is surely enough to negate the E-fields, and i think HV DOES trigger Gieger counter 'cause it accelerates electrons so much that they blast atoms' inner electrons away and produce high energy radiation, specially static electricity, because of strong local E-fields.
we shouldn't underestimate HV, just look at this crazy stuff:
en.wikipedia.org/wiki/Terrestrial_gamma-ray_flash
Nice! I bought a X-Ray tube from United Nuclear with a 25kV power supply. It's generating X-Rays! I checked it with an EMF detector and got background, so no interference! I placed my camera close to the tube, turned it on, and I got beautiful scintillations flashing in the video from the X-Rays striking the lens. Makes it look grainy. My Geiger counter goes nuts if I'm fairly close, and it will peg out the meter. I get noticeable increase in counts/minute from across the room. I plan on doing other tubes. Thanks!
This is a very cool experiment. Loved how you explained the sparking observed. It is fun to discover how things work.
To tell if it is really x rays, take a sheet of lead or even steel and slide it between the tube and the counter. If it is spike interference, the counter will still click away. If it is X rays, the counter will stop counting, or reduce count drastically since the low voltage X rays don't penetrate the lead. Fluorescent screen, you will not be able to see glow with your eyes until the dose rate is in the hundreds of MR per hour, a very high rate and not possible with your power supply current.
This is one of the reasons I love this channel. You never know what weirdness he's going to uncover using a items we could almost all afford.
The geiger counter is a Mighty Ohm kit. Search the web for mightyohm. Glass can be coated with ITO to form a conductive layer. This process typically requires a vacuum chamber or sputtering setup -- probably much more expensive than buying glass already ITO-coated. Still, it might make for an interesting video.
I see the video is already so old, wow good run! I´m enjoying your videos!
Anyways I´d like to add that it IS possible to arc even in a perfect vacuum. The ions can be ripped off the cathode material creating a conductive path.
Works in micro plasma thrusters. I had one tested in UHV. However, you need like 10x the voltage of same gap in air.
Hi' id realy love to see inside your high voltage transformer there, would you please make a video of the top plate removed as id love to see what the transformer looks like, and if its in a poxy or a dry ferrite transformer with apoxy around it " like a flyback transformer from a crt tv,
Many thanks for sharing,
☆☆☆☆☆THUMBS UP☆☆☆☆☆
epoxy
I would agree. The glow is caused by the little bit of air in the tube being ionized by the high voltage. Nitrogen glows purple-blue when ionized.
I really liked this hazardous experiment, thank you for your kind effort and clear explanation.
JIMMMMMYYYYYYY
I did something like that with an old slightly gassy 6JE6. Ran one end of a 12Kv neon sign transformer to the plate cap. Yeah, just like that, the tube glowed blue, but the getter deposit had a ring of green light coming from around it. I shut it off!
What is getter deposit?
Your tube was just simply running as a glow discharge lamp. calculate the wattage. I'll bet it didn't even warm up.
Are you sure the geiger counter is responding to the X-ray and not its electronics responding to the EMI of the breakdown?
so it takes 30kv in the uA range to produce x rays !!! so if you use say 25kv them the peak V could easily make 30 plus KV meaning x rays are easily possible and quite likely .well im glad i got a Dosimeter .more people should be watching this as they think there safe and in reality there not as safe as theylike to make out .great video ,John
these low voltage X rays do not pass Glass easily. You need something above 30kv to get some penetration power.
your punctuation spacing, its very unique.
Its like me unique LOL I'm shit @ that kinda stuff .Never have been good like that ,but I do have other good quality's I just haven't found them yet ;)
HighVoltageProjects: "so it takes 30kv in the uA range to produce x rays !!! so if you use say 25kv"
==25 kV will produce x-rays. A lot of tvs use 25 or 26 kV. Even small TVs that use 15 kV produce it and they all have a metal shielding in the back. The glass contains strontium so that it also acts as a absorber for X-rays.
I get that feeling too, to be honest, since the phosphorous didn't fluoresce.
I'm a chemistry student, and we have to wear radiation badges in the medical department and in the lab while preparing radioisotopes for injection into patients;[18F]FDG mostly; we use a machine but still have to handle it
Also, I've seen duct tape produce x-rays when pulled apart. O.o
Still, you can be denied a flight if you go over your annual limit, so it might be a good idea to get a radiation badge regardless
Ohhh god bless you for feeling things and being honest and god bless you for injecting people with radioisotopes and god bless isotopes and ionizing raditation and god bless god for making things decay and god bless chemistry because without chemistry how would we understand neurons or charge gradients and god bless x-rays and cats who eat hair
I used to do this with dud horizontal output tubes (e.g. 6JE6C, etc.) using a 12 kV neon sign transformer (so that's about 17 kV peak). Oddly, it was the getter patch on the glass where the x-rays were emitting, a nice ring of green glow around the patch. Actually it breaks my heart to see a perfectly good 811 being abused like that but I guess old burned out tubes are not as common as they once were.
Could X rays be created using a camera flash capacitor connected to the vacuum tube creating a short burst of X rays? Would such a capacitor deliver enough voltage?
Nice to see another ARRT on here
ebay sells tiny china step up devices that claim 40kv, i didnt take these claims seriously until i found that i could make 1cm arcing with only a tiny single aa battery as input to the thing..
But those things pulse really slowly and sloppily though. I think his PSU is continuous or has a very nice waveform.
Where? I'd love to get one for my students.
Chris Petrie search "high voltage converter" on ebay and look for the small black cylinders with wires coming out.
yes its bought from ebay, great tiny device, I loved it very much, value for money, be sure not to overload it and don't let it run without allowing the other end to discharge, it can ruin the module easily as well
You could easily be producing 10,000 volts with your rig, just not much current. Even the magneto of a lawn mower engine can produce that high of voltage.
Neat. You know you pushing some electrons when glass becomes ionized.
I think the geiger is reacting to EMF high voltage, not to the x-rays. ( its happen with fluorescent lamp and reactors and stuff too). its a metal geiger normally it will react to gama, or interference from near EMF.
A true geiger counter is actually trying to measure particles, like radioactive decay. X-ray is actually a very high spectrum of light, I don't even think a geiger counter would even respond to X-ray radiation. it needs either beta or gamma.
Not true, gamma is also a very high spectrum of light, just a tier above x rays. I have a geiger coutner and it picks up x rays gamma alpha and beta, only alpha nad beta are particles
Don't feed trolls haha
At such low kV the spectrum of x-ray is gonna be very soft- not surprising barely a single photon is getting to you. I'd be really curious how many µGy is hitting the intensifier- I've shot CR cassettes and it takes probably more like 1000µGy to get a good visible-to-eye glow. I'm really interested to test a GdOS and CsI scintillator but unfortunately they are sandwhiched to TFT so I've not been able to get a straight sample to try. I have an interesting story about the company who made your intensifier
Hobbyist x-ray trivia: soft (tens KeV) x-rays barely penetrate common GM tubes. Try alpha-window tube, then your counter will roar even when held feet away.
Rather than Intensifier, try Zinc Sulfide paint on black paper, then put the x-ray source behind the paper. Dark-adapted eyes will see some flashes and glows. Good source of large amt of ZnS is Speedball Night-glow fabric paint from art supply stores for around $15.
Safety: compare to solar UV of similar photons/sec rate: insignificant!
Arcs in a vacuum are possible. They are not like conventional arcs though, they are called vacuum arcs and are basically just hot spots that form on the electrodes and lead to more current flow.
Medical X-Ray tubes rotate the anode at high speeds to lessen buildup, accumulation of deposits, distribute heat buildup and increase the service life of the tube.
How this man nonchalantly plays with Scanning Electron Microscope and X rays on daily.
I doubt anyone is going to read this and really understand it, but the "x rays" shown in the video is just RFI from the arcing inside the tube. You have to be upwards of 90kv to get xrays. I was reliably able to generate xrays in my home lab, but it wasn't near as easy as hitting an old tube with 15kv. I used 120kv and an old mercury puddle rectifier that I modified with a hot cathode and a tungsten plate. Not saying ANY xrays would be generated using your method, but it is an ultra minute amount with no energy.
Monel Funkawitz That is inaccurate; x-rays can indeed be produced with as little as 15 kV and using certain receiver tubes. I have used the method to usefully expose polaroid film without any phosphorescent material. It is weak, but present nevertheless.
If it isn't glowing green, it isn't producing. Not blue... green. If you are trying to light phosphorus, you really gotta nail it. To cold cathode, you need a functioning anticathode, and your target inside the tube needs to be dished to focus the xrays. You gotta hit it hard if you want high energy xrays. I had mine to the point where I could develop film with a chicken wing as a finger analog in a 2 second burst. Figured I better quit before I screwed up and triggered the remote with me in close proximity and got blasted. My tube had a green glow to it and I had to water cool the target. A lot of work, but it did work. I tried tubes, bulbs.. everything, but could not get xrays without a heated cathode, and could not get high energy xrays unless I got close to 100kv. You could tell on the electric bill when I was playing... lol.
I was using OLD 6BK5 tubes (thin light glass bulb). Very slight voltage applied to the cathode heater; just enough to eject some electrons, but not so much that would load the HV power supply below 15 kV or so. And yes, a green glow was noted, in addition to a permanent discoloration (brown) of the glass.
Cool stuff.
Monel Funkawitz how you explain the Geiger counter?
Emi/rfi. Put the Geiger in a completely sealed and grounded metal box and see if it triggers or wrap completely in aluminum foil that is grounded. Xrays will penetrate that AL no problem.
If you start into the dark path of ionizing radiation, make sure you KNOW what you are doing and have redundant safeguards in place. I had a friend learn the hard way that just because the detecting equipment isn't working right, doesn't mean the danger is not there. You can get a fatal or cancer causing dose way before you feel it.
are you sure your x-ray detector is detecting x-rays in your setup? am asking because you had it very close to your tube. it might simply be influenced by the strong electrostatic field your were applying to the tube.
there are several ways to test this. one of wich is applying the inverse square law.
good luck
+Amira Lozse Good thinking! But look how every beep occurs consistently with every current peak in the amp meter of the power suply. When current flows, the amp meter detects it and that current are the electrons hitting the other electrode and producing the radiation. I don't know if i'm missing something here. Maybe the magnetic field of the electrons is influencing the readings of the metter but the current is so low I don't know if this is possible.
Good idea!
I am using 1J29B subminiature tubes that have a 1.2v filament voltage in guitar effects distortion pedals as a diode for clipping to make distortion. Because of the low filament voltage of 1.2v these and a few others work great. Recently I purchased 100 Sylvania 5642 tubes for $20.00. But their is a warning about possible Xray dangers. From what I can gather this is only at the high voltages like 25kv. I am only running at up to 1.2 usually. I am experimenting with overvolting the the 1J29B tubes at up to 5 volts. Want to do the same with the 5642.
Am I correct in believing the 5642 is safe at low voltage of 1 to 5 volts?
Love how you laughed at the end there lol
some ppl already mentioned it, but high voltage + vacuum = X-ray , you do not want that ☢☢☢⚠
@@alos10subspasomipack33 gee, really?
I remember hearing a theory that the "electrons" travelling between electrodes in a tube are actually composed of mostly Beta radiation. This seems to make sense, since beta is easily directly convertible to electrical energy, and apparently would produce a characteristic glass decomposition reaction usually seen on tubes that have been in operation for a long time.
Beta radiation IS electrons. ;)
Thanks for the info :)
About the conductive glass: I don't need conductive glass in particulair, I need something that is see-trough and conducts electricity. Maybe some sort of plastic, or a thin layer of metal deposited on a surface (maybe even graphene)? I was thinking of metal nanoparticles in water, and then evaporate the water so only the metal would remain.
I find $30 for a sheet of 10x10cm a bit to mutch for a school project, and I will be needing quite some glass.
Thanks for your time
E field affects geiger tube and circuit of instrument. To make the experiment correct , the X Ray HV and tube circuit should be shielded.
Seeing the tube glass floures blue was interesting, altho, what was causing it to glow orange inside the elements of the tube?
Cool video, can I use CRT tube for this experiment ? thanks
he changes his studies often and will probably only do this for a couple days or less. at this rate he will not be subject to much if not any. im sorta like him but for weeks on end i was subject to my small amounts of radiation created in a similar way. it did not case any problems at all just sum head akes from ozone. but nothing from xrays. and i do have to say you have a very very cool job / internship.
I used 811A's in many Tesla Coils, but those were running at 1200 VDC plate voltage. You're 10 times that.
I would really hate to see a video that showed X-rays coming off an 811A at its usual operating voltage!
Thanks for a very interesting video...
-- Dave
Flip the screen over and take a long exposure photograph of it.
Also, you should up the voltage quite a bit, at 20keV the photons don't penetrate all that well.
Then there's nothing stopping you from making radiograms :)
I think you need to make your own tube. You have all the stuff.
I am currently doing a similar project. I am looking at using a General Electric GL 8020 tube. Unfortunately, I do not have a HV power supply, so I was going to make one using an emco dx250. Good thing raw lead isn't that expensive :)
Actually ice makes x-rays as well, comets and glaciers are natural sources. Not too sure the mechanics but happens when it fractures from thermal expansion stress
What kind of tube(s) looks a lot like the 811A but without the interior wire attached to the metal end cap?
"A new MIT study suggests you could go 400 times higher than average background levels and you’d still not suffer very much genetic damage. The current limit for evacuation procedures is only 8 times background radiation Then I read studies suggesting even the tiniest radiation exposure can cause gene toxicity And I've seen studies claim low dose radiation can even be good for you So it seems there is no correct standard. It varies by person. Your genetic makeup most likely determines the risk"
==There is no reply button for some reason. Apparently, there was a study on rats and since our physiology is close to them, it stands to reason that it applies to us as well. It is rather counter intuitive. The problem I see with radiation is that the damage it does is random. You might get a tumor because of 1 single mutation and you might not. Some people in Germany go and sit in old uranium mines, in sofas to get their radiation dose.
something tells me no dose of radiation is directly good for you.
OLEMINER49ER Your "something" is wrong.
If its killing cancer it can be ; )
Vrej Egon Spengler One DSB can't in itself cause cancer. You receive more in a month from aerobic metabolism than a lethal dose of radiation, but it gets repaired.
Vrej Egon Spengler
"...not suffer very much gene damage." Very much??
Well, it takes only a single mutation to cause cancer.
Marie Curie died after her radiation exposure. So we all die, but why are you wanting to speed it up??
Very cool and informative. Subscribed.
Those are probably soft x-rays. However, don't expose yourself, you know it's a cumulative thing.
If I were you, I'd take a lead sheet and make a shield for my family jewels. Sort of like a cup or something, encased in a plastic wrap, to put in my shorts.
If you plan to make more energetic rays or do this more often, I'd recommend a large surface lead shield behind which you can hide efficiently.
Experiments are great, but if you damage your health, nothing is fun anymore.
It is possible to have a spark in a vacuum, at high voltage you will have a electron cloud around the negative electrode (well that might not be a TRUE vacuum if there are particles like electrons in it, but hey...) And if the tension is high enough (or electrodes close enough) you will have a spark even in vacuum.
I was just reading about x-ray tubes today. I didn't realize how inefficient they are. Apparently only around 1% of the total power is actually converted to x-rays. The rest just turns into heat on the anode where the electrons are hitting it. Seems like more efficient tubes would be a good area for research.
Frankly not really, few people want to buy such tubes and even fewer can [legally] buy them, the market for xray tubes is small, and people that buy them tend to have a budget high enough that energy efficiency is not an issue. It would only make sense if they became common household items, like a kit to do xray scans on yourself, but stupid regulations would never allow such a thing to be sold
I like your explanations. Great vid!
i think the giger counter is just picking up stray electrons from the high voltage itself.(interference) im 90% sure thats what is happening and the pannel only glows because of the reflection of light emitted from plasma. this should be emitting xrays but a very very almost undetectable amount as you just made a plasma ball in an impurfict vacuum. being able to heat the filament ant a high voltage potential would make much more xrays
That would make a nice novelty light for the retail market if you could eliminate any noise...!!
Wonder if you could make a vacuum tube without a tungsten filament, replace it with a uv led since uv has enough energy to move electrons, perhaps use a material in which when uv light hits it it throws off more "free electrons"
Would drastically reduce power demands and heat issues, also could open up different drive characteristics since also the led could also be digitally controlled or even pulsed at different frequencies or even intensity
try using a large clear filament type light bulb instead of a tube. I've had some spectacular discharges just using an Old Ford coil with the secondary lead firing into the solder buttom on the end of the bulb. Don't use the coil ground either just let it shoot out the ends of the filaments. 350-500 watt old filament bulbs are great for this, if you can still find them? Cheap too.
I tried to feed high voltage to a vacuum tube, I can only get around 10-20 microsievert per hour, and it is not intense enough to light up the intensifier screen with 400 gain. I am using 10kV as well but mine current might be too low. I will try to increase the voltage and current to see if I can get more x ray. I also tried to heat up the filament then apply the high voltage, but I don't know why somehow the filament is burned.
3.6 Roentgen, Not great, Not Terrible.
Well, changing the length of the tube isn't going to make the electrons more energetic, it will just take a higher voltage to get them moving. (remember eV is a measure of energy)
I know that, perhaps I should've been more accurate about my idea: Salty water is still see-through. If you have to look through it in a horizontal direction, you could use some sort of a small fish tank with electrodes on opposite sides.
I've heard recently that geiger counters have a lower limit one what x-rays they can detect - I see geiger counters on the internet claiming minimum energies of 10keV, 40keV.... (I don't know whether that's just the case blocking them, or something fundamental about the mechanism of geiger counters.) You started getting a reading at 15kV, how do you know it wasn't blasting out 9keV x-rays well before that? (Kinda spooky.) In general, even - how would one tell if you're being irradiated by low energy x-rays?
It might just be static the GC beep on, how you sure it is x-ray
When he turned it on, the GC started beeping a lot more than background.
A bit late, but with every discharge happening inside the tube there is a loss of vacuum due to outgassing and I would expect the glass is lead glass as its an easy glass to work with over soda lime. Lead glass is about 20% lead although it varies. Being lead this would block the small amount of x rays produced.
where did you get the hv power suply from??
Oh,he harnesses the sun's cosmic rays and turns it into electricity.
You really need to get up to 50KV before you start to produce any x-rays energenic enough to penatrate the glass and metal inside the valve. Most flouroscopy is done around 3 => 8mA. Plus there's the inverse square law with any radiation, visable or not. And intensifying screens don't light up that much even if they are in the primary beam. You need the very old ones that were used for short exposures or an old flouro plate. Great video with your limited resources. Oh, one more thing X-Ray tubes are about 1% effecient. 99% of the energy is turned into heat. (That's why the anodes spin) The noise you hear during a X-Ray.
"I'm fairly safe here from behind the camera" he says with a nervous laugh...
Take an HT rectifier from a old color TV, put on the HT and you have Xr
It is probably not arcing in vacuum but produced X rays eject electrons from cathode.
this is well known problem which happens in HV systems
What is modulating the blue light from the tube? Is that the regulation in the HV supply?
Old tubes as they get old and enough voltage across it will produce rays! Old CRT based tvs had lead shielding for that reason CRTs emitted rays!
Whatever you do, don't let the dark out of that darkroom !
Yes. In fact, it's good for you.
when I look at this and how long it's on , what voltage it is , what tube it is , and how far he is and u compare it to a dental xray or something im pretty sure this is moderatly safe.
I readed the datasheet. But i didn't find anything for working voltage for it. Is it okay to power them on (200)kv and 2A?
Yes but it is a marx generator not a true power supply for long works
Where you gunna git 400KW from? ;)
WOW as low as 15KV and your making x rays !!!!!!!!
You should search for Grenz Radiation, used in dermatology for treating certain disorders.
Also a x-ray therapy in Austria that I heard of uses 13kV to treat some skin disorders.
You need a beryllium window to enable these low energy particles to escape.
I saw somewhere saying you need 300Kv to make xrays...
@@fidelcatsro6948 that's incorrect, even old CRT monitors/tv's did emit a tiny bit of X-Rays, while those operate anywhere between 17kV to 30kV (depends on the size).
the reason crt's had such little x-ray output though is because, well, the glass is REALLY thick.
@@BH4x0r so that means a Tesla coil or even an exposed spark plug arc..could be doing the same right?
@@fidelcatsro6948 no, the tube needs to have a vacuum, people even achieved x-rays with properly sealed glass capacitors (it needs a very deep vacuum, which old CRT's also did have)
so a. your tube needs to have a deep enough vacuum
b. your source must be powerful enough, so it's not only about having 15kV but enough (m)A current too.
c. i'm sure tesla coil's don't have a powerful enough current output AND i think, this is where I could be mistaken, but i think you need a proper closed circuit (like one wire at one end of the transformer's coil and one wire at the other end)
maybe it IS possible if you hook 1 end of a tube up to ground and the other end close to the tesla coil, but as i said i don't think thats powerful enough as it's not just about the volts
but no in OPEN AIR it's not possible so that's all safe
pretty cool.
These phosphor screens have to be sort of "reset" I think after exposure,
Why not try a high voltage rectifier tube like the 1B3GT?
I saw an interesting video of someone producing significant X-Rays just by unrolling Scotch tape in a vacuum.
Well, probably not that much radiation there I think, since you're only operating it at 20000 volts and not for very long. Also, the glass doesn't let much radiation through. Not at these low energies anyway. X-ray tubes are generally made with a window where the glass is quite thin. However, playing with radiation is always a dangerous thing to do.
So the glass is actually a better scintillator for low energy x rays than the phosphor screens for dental work.
My dumbass thought that he made this experiment using a "Vacuum cleaner tube" until I read the title again
nice explanation but were you using the cathode tube as a spark gap device enclosed in vacuum? i try a lot of experimentation with ignition coils and buzzing switches to run them on open spark gaps, am i exposing myself to xrays?
read somewhere you need 300kv to make xrays..so I guess not..
Did you make that giger counter? and if so, did you make a video on how?
You make wondrous things happen in you garage. I wonder if your neighbors know who they're living next to...
Sorry, a quick wiki shows it was simply radiation that killed her.
"from aplastic anemia believed to have been contracted from her long-term exposure to radiation."
You did it so I didn't have to. Thanks.
Hi Ben, I am not convinced that what you measure is X-ray. My Inspector GM counter indicated a high reading, 20 µSv/hr, when placed at a distance of 10 cm from a sparkgap Tesla coil. When I replaced the GM counter with a scintillator, I measured only background. Besides, a GM counter is very insensitive to low energy X-ray (below 40 keV). I believe that what you measure is due to the electric field your tube generates, which disturbs the GM tube. See my channel,newest video. Regards, Alfred
my high school shop teacher bet me I could not do this.... then almost kicked me out of school when I proved him wrong..... just like this! But he did give me the A he promised.
so moral of the story, those lead Pb robes are not needed in the X-ray rooms no more.
20KV X-rays are too "soft" to get through the glass. Why should the tube arc over? The enode connection is on the opposite end. Maybe you should short all the pins on the bottom together. Another thing: all X-ray tubes, after a long period of non-use, need to be "cleaned up" by slowly increasing voltage, and waiting for residual gasses to be sputtered away.
It is unsafe. Geiger tube have low sensitivity to soft X-rays.And soft X-Rays are the ones more lethal to the humans.
Is this vacuum tube the type from old tvs
You implied that the geiger counter test was the answer to Xxdixon79xX's question, which it's not, hence my comment.
That being said, I would still call this safe.
The voltage he's using is very very low, in medicine we use at least 45 kV and even then it barely registers on our dosimeters (a little cassette thing we use to measure how much radiation exposure we've had).
I also did some experiments. (statute of limitations: more than 7 years ago!!!) with pulse tubes including 5642, DAC32 and others. Interestingly I *did* get my intensifier screen to light up an RFID tag through a Maplin project box though the only casualties were my phone and a memory card or 3 that got nuked while experimenting which also damaged the onboard camera. I can assure you that my dose was minimal based on multiple redundant dosimeters with two different tube designs and lead sheeting. Not sure why but did also find that putting the tube under oil did not help much as it still failed. Perhaps worth investigating? The module I used for this experiment was intended for lighting gas on a large industrial boiler so designed for high reliability: the smaller potted transformers sold in handheld lighters aren't quite enough though are useful for a different project like powering a Gen 0 13.5KV NV tube.
like every video, awesome!
someone know where can i find or buy the fluorescent intensify screen?
You can buy it on ebay, or try to make it yourself.
but if you just want for detection you can use any video camera, it will show "snow" if exposed to X rays.