I'm only a few years older than David Hahn. In the early mid nineties, I was also building a nuclear reactor on the down-low. I got my first neutrons a few days before I turned 21. My name is even David as well. So, my friends would always compare me with him as soon as they heard his story.
I've always felt a bit of kinship with him, particularly his desire to learn-by-doing about nuclear physics. I've also felt a bit of jealousy at the press he got, pity for the mess he got himself into, and I'm not sure what to name the feeling (sadness? derision?) for some of the mistakes that he made. I'm not sure that I would have done better at his age, trying to do what he was doing.
There were things I did that were different from him, that I guess led me to a different fate. I made sure not to break any laws (deuteron colliders are under a different set of rules than radioisotopes). I went to college, which was probably easier for me than for him. I involved other people in my project, including getting VC funding. I sure never made a mess like he did.
I also made some similar mistakes. I wasn't even aware that high voltage power supplies would make x-rays. I was shocked and scared when Spence, our 'adult supervision' engineer, brought in a Geiger counter and showed us that we were making a fair amount of x-rays. I learned a lot of radiation safety on-the-job, quickly. Without Spence, who knows how badly I would have irradiated myself before learning on my own?
We always avoided publicity. Part of that was because we didn't want people freaking out that we were doing "nuclear stuff" in a rented office by the railroad tracks in Tallahassee. Our landlord knew, and was cool with it, but we were nervous about how the general public would react. So we kept things private.
I used to feel that maybe it was a mistake to keep my fusion project so secret. It certainly didn't help my career to be a failed founder with no published papers, without even a press release to point to for my years of work. But when I look at how the mistakes that David Hahn made followed him his whole life, and which weren't all that different from mistakes I made in my youth, I think maybe my decision wasn't so bad. "Radiation Safety Officer" happens to be one of my job titles these days.
What kind of high voltage power supplies? Now you've got me worried as I played around with Tesla Coils, spark gaps, neon sign transformers a lot as a kid...
Well, the penetrating depth depends upon the voltage, and there needs to be space for the electrons to accelerate (this means vacuum or air, dialectric insulation in the air gap cuts it down). Anything above around 15 kV has 'potential' for x-rays which can penetrate beyond your skin and do some damage. We were working with 180 kV power supplies, with a 10 inch vacuum-filled free fall distance for the electrons, so we got a goodly amount of rays.
You can get x-rays off of Tesla coils, spark gaps, etc., but usually the dose rate is fairly low. It is worth measuring though, especially if you will be exposed for a long time or its close to your body. Typically it will be below around 1/100th of your yearly exposure limit per hour. So, if you are playing with one for an hour, no biggie. If you are planning on putting one on your 40 hour/week work desk, think again.
I once made a helmet for Halloween with a pair of Tesla Coils, one on each side of my head. The helmet was conductive, and it would look like the sparks from the coils were going through my head. This was not what I would call 'safe' (body-mounted high voltage can go badly wrong), but it was a lot of fun for one night. I made sure to keep the voltage below 20 kV, and reduced my exposure time by only running it when I wanted to impress people (mainly cute girls).
Hi. Newbie here, but I've been following this story. It sounds rather tragic.
This might be slightly off-topic, but is there any possibility that someone could conceivably "weaponize" an x-ray or gamma-ray emitter, e.g., for a terrorist plot?
I came across this article about an earlier half-baked plan from 2012. Some white supremacist had "allegedly planned to use a remote-controlled X-ray weapon hidden inside a van to vaporize Muslims in upstate New York and launch an attack on the White House." This seems to be stretching the limits of plausibility. (Obviously, this wouldn't have been some science fiction "disintegration gun.")
However, let's assume that we had some James Bond super-villain who had unlimited resources and a stable of highly-trained engineers and Nobel physicists as his minions. Would it be within the realm of plausibility to build such a thing? Or would this still be complete science fiction?
More specifically, could an emitter be be made that generates x-rays or gamma rays in a non-directional way so that everyone in the vicinity received a lethal radiation dose over the course of a few minutes? How much electricity would this take, and what type of potential range might it have? Would buildings or car doors tend to block the radiation? Would the victims somehow sense that they were being irradiated (e.g., a burning sensation)?
I'm not looking for technical blueprints or anything, of course. It's just a thought experiment. (Hi, NSA!)
I think once you start getting potentials over 10 kV, the Schottky effect starts to give minor x-ray emissions.
The more major or typical source is from tubes. Most tubes at high voltages will emit x-rays, even if that is not their intent, from an emitted electron striking the anode. This is why CRT TVs usually used thick leaded glass, to block the x-ray emissions.
Can you touch on ANY details of how this is possible with 'every day items'? When I think of a reactor, I think of something that looks super complicated and engineered, like CERN. It's hard for me to imagine how a reactor can be built by a boy in a shed... what materials did he need? What powers it? What (if any) safety measures are taken... even rudimentary ones?
But IIRC the everyday items were smoke detectors with Americium and uranium from old painted clock dials. I think he found a full vial of dried uranium paint hidden inside some random old clock at an antique store.
Based on the details like deuterium fusion with high voltage, my guess would be that FiatLuxDave built a variant of a Fusor. It is a challenging project but not out of the reach of a dedicated high school student.
The physics what we are looking at is the fact that neutron capture requires neutrons that go at a very specific speed. So, the nuclear fule creates some initial neutrinos that go fast, the carbon slows it down to a sufficient speed that they are captures by rest of the fuel, which then causes more chain reactions.
This is the reason reactors are a bit delicate - not enough neutrinos or wrong speed - no reaction. Too much - booom.
Why do people keep repeating this? Reactors don't go 'boom'. They aren't thermonuclear weapons. The worst you'll get is a bunch of heat when the cooling system fails and a possible steam explosion.
It depends on the design of the reactor, doesn't it?
They aren't thermo-nuclear bombs. They are simple nuclear bombs.
The earliest types of nuclear bomb essentially smacked two sub-critical masses of nuclear material together to form a super-critical mass, or compressed a sub-critical mass to a greater density, such that it was super-critical at that higher density. Then the core material produces heat faster than it can be radiated away, and eventually explodes.
If the non-fuel components of the reactor are destroyed, there may be enough nuclear material present to combine into a super-critical mass. At that point, it will go boom unless someone acts quickly enough to stop it.
It just so happens that all reactors designed to actually be built are ultra-paranoid about not turning even a completely failed reactor into a nuclear bomb. In a backyard DIY reactor that is not following a design blessed by physicists and engineers, you might get a boom. You will more likely get a big, deadly, radioactive fire that drops toxic ash on innocent bystanders, but if you melt cylindrical fuel rods in a graphite moderator, and they pool in the bottom of a spherical containment vessel as one big, connected mass...
I will ask again: Why do people keep repeating this?
You keep throwing around ideas like "They are simple nuclear bombs". It's not like during WWII the US asked some physicists to make a weapon and they replied with "just put some of this in a box and drop it on Japan. Call us when you need more"
Here are multiple explanations as to why a reactor is not and can not be a bomb:
One of the design constraints of a bomb weapon is that it should not go off before you want it to explode.
Another constraint is that you have to be able to get it to the target area while someone is actively trying to stop you from doing it.
Finally, a weapon has to direct its energy such that it destroys the intended target, rather than dissipating most of it uselessly, or harming your own assets.
That's why the physicists didn't just say to refine some plutonium and lob it at the enemy.
There have been 60 criticality accidents, with 14 fatalities. None of these resulted in an explosion (excluding steam), but that does not mean that a criticality accident cannot cause an explosion. A lower critical mass will produce more "flash" than "bang". It can still make a boom. The pow from a cherry bomb is as much an explosion as that from a 500-lb military munition.
A failed reactor will not destroy any cities, like the first nuclear weapons. But it could destroy a back yard, and render the surrounding neighborhood uninhabitable for many years.
"Boom" in this context I assume doesn't mean kilotons of TNT equivalent explosion, it means "criticality event resulting in the release of a lethal dose of radiation". At Los Alamos, Harry Daghlian was killed by the "boom" resulting from simply accidentally dropping a brick onto a core of nuclear material.
"Boom" was a bad imagery perhaps given the prevalence of nuclear weapons in the common thought, but not misplaced given the generality of the discussion - in this instance, I meant an interesting event consisting at least of a sudden spike in neutron flux and heat production.
A "reactor" in this instance referred to an assemblage of nuclear material and neutron moderator to create sustainable chain reaction. Without the cooling tanks and pumps required for power generation, or the compression mechanism required for a fission bomb.
If you assemble a particular configuration of nuclear material it will go super critical
It wouldn't be inconceivable for a determined person with some electronics experience to make a cyclotron [1], which is a neutron gun that can produce radioactive material. Not sure if "reactor-in-my-garage" folks are doing this, or if the material it produces can be used in any subequent reactions.
The lack of details in the obituary make me think he took his own life.
Regardless of how he died, Hahn's story taught me it was possible to learn and build without the latest and greatest tools and equipment. His approach to safety was concerning (to say the least), and he stole a lot of the nuclear material he used, but I think it's important to realize that amazing work can be done without millions in funding. This is probably not a huge revelation for the field of computer science, as even a powerful computer can be bought for relatively little. However, it's easy to look at the equipment used in the physical sciences and think that you need the same equipment to make a meaningful contribution to science. A world of possibilities opens up once you have the idea that you can make the equipment you need to run the experiments yourself.
One of the things I love about the internet is that we can share our experiments and hacks with each other. There are a lot of great YouTube channels that are spiritually aligned with mentality behind Hahn's reactor. I'd personally recommend Applied Science, as well as Cody's Lab, and I'd be interested in hearing about any channels that other people find interesting.
His story is very sad. He joined the Navy after an young adulthood set adrift after the suicide of his mother. He was discharged and diagnosed schizophrenic. Ten years ago, he was arrested for stealing smoke detectors, and the court proceedings implied he'd gone off his medications.
I'd heard parts of that story. He reminds me of one of the people who I went to school with. We shared a lot of hobbies, but his antisocial and self-destructive tendencies meant that I never could really consider him a friend. He was incredibly smart and capable, but he always acted like he had something to prove. He was expelled from high school for hacking, which unlike a lot of "expelled for hacking" stories, was entirely legitimate. He was doing some pretty impressive exploits on the network computers, but then he was also downloading information he had no business possessing. I was interviewed by the FBI about it, because I was president of the cs club, and he had been using our computers.
During his expulsion he took the classes needed for college and applied to the CS program at a prestigious state school rather that coming back to high school. It was really impressive -- between the grades he had skipped before, and the grades he skipped going to college, he got in before he was old enough to drive.
I don't think he ended up graduating from college. He is very capable, but he needed a mentor who was operating on the same level as him to help him develop emotional and social skills on par with his intellectual talents.
The saddest bit is at the end of the Harper's[1] article which I originally read when it was published:
--
Because it is so potent, the radium that David was exposed to in a relatively small, enclosed space is most worrisome of all. Back in 1995, the EPA arranged for David to undergo a full examination at the nearby Fermi nuclear power plant. David, fearful of what he might learn, refused. Now, though, he’s looking ahead. “I wanted to make a scratch in life,” he explains when I ask him about his early years of nuclear research. “I’ve still got time. I don’t believe I took more than five years off of my life.”
Yes, plenty. The problem is radiation is incredibly wide ranging including wildly different materials and effects. Much like there isn't "the" treatment for electricity. You mean UV damage to the eyes from being exposed to arcs or thermal explosions or shock to heart or RF burns or ... and radiation is the same.
Also some of the stuff he did was questionable purely chemically. So ... boring holes in lead, you're at least washing your hands before eating, right? Or the feeling I get from this guy, no. Or his refining process involving lithium metal, interesting but not advisable.
I wonder what the guys "banana equivalent dose" was. He didn't get that much material, at least as reported by the press. A thousand times nothing is still nothing unless the true story is more interesting. From what I can find an unmolested smoke detector is about a tenth of a BED/yr so the mere presence of a thousand detectors in one room, if you sit in it for the entire year, is about the same as eating 100 bananas in that year, which I probably do! If you're sloppy and it stays outside your body its about the same. Unless you inhale it.
He accumulated more "stuff" than the NRC feels safe to give out unlicensed, but the NRC is pretty pessimistic so he should have survived. And seemed to have done so, unsurprisingly.
Americium is an alpha emitter (like plutonium, and with a shorter half life). Inhaling it is going to be much more dangerous than one or even many unmolested asking detectors.
To start there's triage. Go away and come back for cancer screening every five years. Stay here and we treat you. You're toast here's some painkillers.
In between there's a wide mix of removing the cause and repairing the damage.
This almost seems too obvious but there's obvious recent surface decontamination, wash it off. A test tube in the lab shattered, well get it all off you first of all.
Only a step past that, if you chug heavy water you'll be encouraged to drink tap water to pee out the heavy water. Likewise if you ate something contaminated an hour or a day ago they'll give you stuff to make your digestive system explode out both ends. I donno if they'd feed you an expectorant for inhalation. There's no point if the exposure was months ago of course.
There are peculiar specific treatments if you've been recently exposed to iodine isotopes from a bomb or very major plant accident they can flood your system with zero radioactivity clean iodine to convince your body to pee out 99% of your intake rather than adsorbing 100% of the bad stuff into your thyroid. Its like reducing your exposure by a factor of 100 just by popping some pills. There are other isotopes like that I can't remember.
If you were doing radioactive labeling experiments obviously they'd flood your body with unlabeled clean stuff to make you pee the glowing stuff out.
If its a bone-seeker there are mineral chleation treatments that are very hard on the skeleton but you'll pee out those isotopes which is better than having them irradiate you from the inside for decades.
If you wipe out your bone marrow you're screwed unless you get a bone marrow transplant. In the short term they could pump units of blood into you. This works better if there's one victim per hospital than if there's an entire Japanese city and the hospital was vaporized, which is why not too much was done along these lines at the end of WWII.
Similar to the above paragraph if you wipe out your digestive tract alongside 100K neighbors there's not much the hospitals can do, but if it was an unfortunate lab accident, you might be kept alive via IV until recovery.
If its a surface burn I'm not sure what they'd do WRT preventative skin cancer, maybe skin graft it on general principles or wait and watch and see if a tumor forms. Obviously there's antibiotic treatment.
So I would draw a line between those. Most of them are treatments for exposure to radioactive materials and not for radiation damage (which I think was more the question being asked).
The bone marrow transplant and supportive care are treating the damage.
Unfortunately, radiation poisoning is an often irreversible process - it involves the destruction of cells, muscle and tissue at a molecular level in a way that our bodies never were designed to be recover from. Majority of medical practices in this space focus on removing ingested or inhaled radioactive particles, to prevent further damage over time and keeping the patient alive and in relative comfort.
To repeat a comment I posted elsewhere [1],
...it is tragic that a child and later teen with so much curiosity and interest in science was not able to get the guidance he needed to channel his drive into a more rewarding and productive life. I suspect many HN readers will see a lot of themselves in David, as did I, and wish things could have turned out differently.
The article is woefully lacking by not answering the question that everyone who starts to read the article must have on their mind: was the cause of his death related to radiation exposure?
He could have been hit by a car or slipped on a banana. This is the sort of lazy news article that we all hate in the world, the implication without the actual presentation of the facts.
Ars is a terrible source of news, this isn't their first offence.
It's even more shoddy reporting if, as some commenters are suggesting, he in fact took his own life (which seems especially likely if he was indeed bipolar). Turning tragedy into a sensationalist story purely for the sake of it.
Journalism is not mindless parroting of online sources. Sometimes you may have to actually ask a living person a question on behalf of your audience, or do records requests. In this case, as a non-journalist, my first vector of attack would be to get the official death record from the county where DCH died.
Seems like an obvious thing to do whenever writing a "notable person X has died" article.
The obituary, for instance, says he died on the 27th. The Macomb County records office [0] says he died on 26 September 2016.
He died in a small town, relatively. So any day of the week someone killed themselves in LA, but not rural nowheres-ville, so the lack of XYZ in nowheres-ville kinda proves something.
His internet public memories page was full of relatively close friends and relatives in shock. So your situation or an accident. The police would be involved either way. I pulled the police log for the week of his death of all police calls in that city and found nothing logged along the lines of any bodies being found or violent crime or whatever. As near as I can tell the only interesting thing that happened in the town where he died on the day he died was a very major traffic accident, the worst thing to happen in town in weeks before and after. There was a twitter-worthy hours long road closing due to a major (aka fatal) car accident. Absence of finding anything proves nothing, perhaps they intentionally censor suicide calls or it has to be considered that "suicide by car" is not unknown, but I would not be surprised if he died in that specific car accident.
There isn't much information online, but I found a local TV story claiming that "David Hahn, the man known as the 'Radioactive Boy Scout', died in his Shelby Township home on Sept. 27 at the age of 39." 'In his home' would seem to exclude a car accident: https://www.facebook.com/ShelbyTwpTV/videos/942897049150097/
Separately, the funeral home "tribute wall" has comments which would seem to imply suicide or drug overdose. In particular, it would seem very odd to say "I believe David finally has the peace he so desperately needed" unless his mental state played a role in his death: http://www.wasikfuneralhome.com/obituaries/David-Hahn-2/#!/T...
Well, his life was a mess. He was arrested in 2007 for stealing smoke detectors and his mugshot looks like someone who is either addicted to serious drugs or is suffering from radiation poisoning, or both.
He also admits to being schizophrenic and talks about how hard his mother's suicide was on him. It sounds like this guy had a hard life. I'm guessing he followed her lead.
> Unless it kills quickly there's almost never a way to tell.
Well, if he was e.g. struck by lightning just before he died, then the odds that cause of death is related to exposure to radiation years ago go way down. The article sadly doesn't even give anything to go on, or even mention the omission of anything about cause of death.
This is a pretty sad story. I remember reading about him (when I was a Boy Scout, actually) and being impressed and inspired, in a way (despite the whole superfund site in his backyard thing...)
Unfortunately he was later diagnosed as bipolar and paranoid schizophrenic. I have to wonder what he could have achieved otherwise.
Fusors perform nuclear fusion, Hahn was experimenting with nuclear fission.
The important differences are:
- The fuels used. Fusion uses the lightest elements like hydrogen and helium, which can be non-toxic and non-radioactive (although it depends on the exact process being used). Fission uses the heaviest elements like uranium, which are very toxic and very radioactive.
- Control of the reaction. Fusion reactions typically fizzle out if the device isn't powered up and controlled very precisely (this is what makes fusion difficult); they're nothing like hydrogen bombs. Fission reactions are typically spontaneous, caused by the radioactivity and arrangement of the materials in the reactor; control systems regulate this reaction, which would otherwise be pretty similar to an atom bomb.
IIRC he was restricted from ever actually working a job that would have let him work with the nuclear reactor. Those navy ships are huge though, so there are plenty of other jobs that keep you far away.
fun fact: navy nuclear engineers are one of the few/only enlisted sailors that can lawfully refuse orders from anyone above them - all the way to an admiral - if they believe the order will compromise the safety of the reactor.
I'm only a few years older than David Hahn. In the early mid nineties, I was also building a nuclear reactor on the down-low. I got my first neutrons a few days before I turned 21. My name is even David as well. So, my friends would always compare me with him as soon as they heard his story.
I've always felt a bit of kinship with him, particularly his desire to learn-by-doing about nuclear physics. I've also felt a bit of jealousy at the press he got, pity for the mess he got himself into, and I'm not sure what to name the feeling (sadness? derision?) for some of the mistakes that he made. I'm not sure that I would have done better at his age, trying to do what he was doing.
There were things I did that were different from him, that I guess led me to a different fate. I made sure not to break any laws (deuteron colliders are under a different set of rules than radioisotopes). I went to college, which was probably easier for me than for him. I involved other people in my project, including getting VC funding. I sure never made a mess like he did.
I also made some similar mistakes. I wasn't even aware that high voltage power supplies would make x-rays. I was shocked and scared when Spence, our 'adult supervision' engineer, brought in a Geiger counter and showed us that we were making a fair amount of x-rays. I learned a lot of radiation safety on-the-job, quickly. Without Spence, who knows how badly I would have irradiated myself before learning on my own?
We always avoided publicity. Part of that was because we didn't want people freaking out that we were doing "nuclear stuff" in a rented office by the railroad tracks in Tallahassee. Our landlord knew, and was cool with it, but we were nervous about how the general public would react. So we kept things private.
I used to feel that maybe it was a mistake to keep my fusion project so secret. It certainly didn't help my career to be a failed founder with no published papers, without even a press release to point to for my years of work. But when I look at how the mistakes that David Hahn made followed him his whole life, and which weren't all that different from mistakes I made in my youth, I think maybe my decision wasn't so bad. "Radiation Safety Officer" happens to be one of my job titles these days.
Rest in Peace, David.