Anatoli Bugorski - survived a particle accelerator...

[athon]

...or did he?

I'm curious to know about this one. The story goes that Bugorski worked on the U-70 particle accelerator in Russia. He allegedly stuck his head into the works to check something out and was struck in the head by the beam. In spite of the radiation etc., he survived.

Read the details on the wiki page (http://en.wikipedia.org/wiki/Anatoli_Bugorski).

Now I'm a little suspicious of this. I thought particle accelerators demanded intense magnetic fields and a vacuum, hence weren't simply like car engines where you could pop the hood and have a sticky beak at the whizzing protons speeding past. Yet it seems that's precisely what he did.

I've no idea if the U-70 is different, or if I'm missing something about particle accelerators. I'm not a particle physicist and don't play one on tv.

Anybody with more experience able to put me straight on this?

Athon

[Graham Jackman]

...or did he?

I'm curious to know about this one. The story goes that Bugorski worked on the U-70 particle accelerator in Russia. He allegedly stuck his head into the works to check something out and was struck in the head by the beam. In spite of the radiation etc., he survived.

Read the details on the wiki page (http://en.wikipedia.org/wiki/Anatoli_Bugorski).

Now I'm a little suspicious of this. I thought particle accelerators demanded intense magnetic fields and a vacuum, hence weren't simply like car engines where you could pop the hood and have a sticky beak at the whizzing protons speeding past. Yet it seems that's precisely what he did.

I've no idea if the U-70 is different, or if I'm missing something about particle accelerators. I'm not a particle physicist and don't play one on tv.

Anybody with more experience able to put me straight on this?

Athon

I can't see any way that you could maintain a coherent proton beam outside of a very good vacuum. However, since the equipment was supposedly malfunctioning, it's possible that protons colliding with the equipment were causing radiation to be emitted. Electromagnetic radiation could easily pass through the equipment and cause the burns

[athon]

I can't see any way that you could maintain a coherent proton beam outside of a very good vacuum. However, since the equipment was supposedly malfunctioning, it's possible that protons colliding with the equipment were causing radiation to be emitted. Electromagnetic radiation could easily pass through the equipment and cause the burns

See, that's closer to what I was thinking. He didn't 'stick his head into the beam', but rather put his head into the equipment when it was functioning and copped a dose of radiation that spilled through. Not pleasant, of course, but not quite as sensational as him looking into a particle accelerator's beam.

Athon

[geni]

well the place exists at least.

http://www.ihep.su/ihep/expu70/expu70_run-e.htm


Depending on how the place is setup there are various options. They could have it set up to kick out beams of hard X-rays and he got hit by one of those.

Otherwise head just outside the pipe the beam is in is probably the explanation.

[BenBurch]

People used to ALIGN cyclotrons and etc by EYE. You can see the secondary radiation caused when the beam strikes your eye. As a direct result, a lot of physics guys from that era got cataracts and worse. Seriously. I'm not joking.

[TMiguel]

There where workers of Chernobyl that got hit by a massive amount of radiation and they lived for years and years. Getting hit by radiation is like playing a Russian roulette (whit the odds stacking against you), not like getting shot at.
Although that pretty much depends on the beam.

[ImaginalDisc]

The beam measured about 2000 gray when it entered Bugorski's skull, and about 3000 gray when it exited after colliding with the inside of his head.

What? Does that actually make sense, because I might not understand the unit involved. I thought a gray was 100 rads.

[krazyKemist]

There where workers of Chernobyl that got hit by a massive amount of radiation and they lived for years and years. Getting hit by radiation is like playing a Russian roulette (whit the odds stacking against you), not like getting shot at.
Although that pretty much depends on the beam.

That depends : there is such a things as a lethal dose. If you get irradiated with a lethal dose, your bone marrow dies off, and you're dead after 2 - 3 weeks if you do not receive a bone marrow transplant. Total irradiation is sometimes used in induction therapy for leukemia : it kills off all the malignant cells (and normal bone marrow) before a bone marrow transplant.

And of course, if the beam has enough power, it can make a pretty neat hole through whatever body part you stick in it.

[Tubbythin]

What? Does that actually make sense, because I might not understand the unit involved. I thought a gray was 100 rads.

1 Gray is the deposition of 1 J of energy per kg of tissue and is a measue of the absorbed dose. I suppose, since the stopping power of the beam will be some crazy function of energy, the energy deposited per unit path length could be greater at the far side of his head than the near side... but it doesn't make an awful lot of sense to talk about the beam itself in terms of the unit of absorbed dose.

[Beanbag]

As someone who's had intimate experience with receiving radiation (post-operative treatments for throat cancer), what I can tell you is that when radiation passes THROUGH you, it does little damage. It's when the radiation STOPS inside you that it has its maximum effect. My oncologist spent a considerable amount of time adjusting energy levels to make sure most everything stopped in the soft tissues before reaching my spinal cord. Based on the side effects I still experience today, he had it about 95% right. I'm pretty sure he "nicked" a nerve or two.

Beanbag

[Graham Jackman]

People used to ALIGN cyclotrons and etc by EYE. You can see the secondary radiation caused when the beam strikes your eye. As a direct result, a lot of physics guys from that era got cataracts and worse. Seriously. I'm not joking.
That's interesting! Were they merely adjusting the beam alignment as it left the cyclotron? I can't see how you could maintain a circulating beam in anything but a high vacuum but I don't work with such things. I've no doubt that you might see things if you intercept a beam of radiation, as I remember it people in orbit recorded optical flashes, thought to be due to cosmic radiation.

[Cuddles]

Now I'm a little suspicious of this. I thought particle accelerators demanded intense magnetic fields and a vacuum

The magnetic fields aren't really a problem. They could cause issues with carrying metal objects, but the fields outside the magnets will generally be fairly small.

People used to ALIGN cyclotrons and etc by EYE. You can see the secondary radiation caused when the beam strikes your eye. As a direct result, a lot of physics guys from that era got cataracts and worse. Seriously. I'm not joking.

Yeah, but cyclotrons are going back quite a bit further than this. Aligning a small, low power cyclotron is one thing, sticking your head in a 70GeV proton synchrotron is not such a great idea.

That's interesting! Were they merely adjusting the beam alignment as it left the cyclotron? I can't see how you could maintain a circulating beam in anything but a high vacuum but I don't work with such things. I've no doubt that you might see things if you intercept a beam of radiation, as I remember it people in orbit recorded optical flashes, thought to be due to cosmic radiation.

I can't find any hard details, but there are a few possibilities. As noted here (http://resources.metapress.com/pdf-preview.axd?code=r71p91n3p8108551&size=large), a new injection system started construction in 1977, and was still being worked on at the time of the accident. And as noted here (http://web.ihep.su/library/pubs/about/sh1-e.htm), a new extraction system was commissioned in 1979, which probably means it was being worked on at the time of the accident.

As people have already noted, it is not possible to maintain a coherent beam without a hard vacuum. However, it is certainly possible for a beam to exist for a relatively short time in air. Both of the systems noted above will probably have, at some point, required a beam to be fired down part of the structure and then dumped into a beam stop before reaching what would eventually be the end. If the dumping procedure failed somehow, it is certainly possible that the beam could travel further down the beam pipe, pass through vacuum seals into air and hit someone further down.

I should note that such an accident could not possibly happen today, certainly not in Europe or the US, precisely because of the risk, however small, of such a failure. For example, in the accelerator I work at it is simply not possible for any beam to exist at the same time as it is possible for anyone to get inside the ring. Hardware interlocks mean that opening doors physically breaks circuits. However, as BenBurch notes, things were certainly done differently in the past, and not just in Russia. Also, as demonstrated by Chernobyl, Russia didn't put an awful lot of effort into making systems physically failsafe, as opposed to just procedurally.

One final point is that radiation doses and their effects are generally noted for full exposure. If a dose that big is spread over your whole body there is really no question that you will die of massive organ failure. However, in this case the does was recieved almost solely to the head. That means there was nothing to cause any problems for organs, bone marrow or anything else. As long as the brain could survive it, there would be no lethal effect on anything else.

Overall, I don't see any reason to doubt this happened. The mechanics of the accident are certainly possible, although indicative of some rather bad and unsafe design and procedures. I'm not an expert on the health effects, but it sounds plausible enough to me given that it would only be localised damage. The main problems with it is that there appears to be very little reference to it, and what little there is is in Russian. Given the whole cold war thing, this isn't really that surprising, but while it isn't evidence to the negative, it does mean it's hard to find any to the positive either.

[BenBurch]

Correct, much lower power for the cyclotron exposures.

Note that we DO use proton beams to treat cancers; A use that was pioneered at Fermilab back in the early 80s when I worked there. But we were talking about beams output from the LINAC, not even beams from the booster or the main ring; I think we were talking 400 MEV energy or thereabouts.

[BenBurch]

That's interesting! Were they merely adjusting the beam alignment as it left the cyclotron? I can't see how you could maintain a circulating beam in anything but a high vacuum but I don't work with such things. I've no doubt that you might see things if you intercept a beam of radiation, as I remember it people in orbit recorded optical flashes, thought to be due to cosmic radiation.

Yes, we are talking about the beams that were exiting after hitting a target or beams that were exiting someplace they were not meant to exit that were being intercepted by eye.

Eventually as the risk was more fully appreciated people would use plywood sheets covered with polaroid film to look for beam exit; You'd run up the accelerator for a bit, stop it, go develop the film to see how much you were missing by, adjust your magnets or your charged plates, and try again.

Getting a beam orbit in the Fermi accelerator using this method was quite time-consuming. Now they have sensors that do the same job and can establish an orbit in a couple of shots. This also means that the magnets and other gear in the beam tunnel is less irradiated and so acquires induced radiation much more slowly which is a Good Thing.

[Cuddles]

Yes, we are talking about the beams that were exiting after hitting a target or beams that were exiting someplace they were not meant to exit that were being intercepted by eye.

Eventually as the risk was more fully appreciated people would use plywood sheets covered with polaroid film to look for beam exit; You'd run up the accelerator for a bit, stop it, go develop the film to see how much you were missing by, adjust your magnets or your charged plates, and try again.

Getting a beam orbit in the Fermi accelerator using this method was quite time-consuming. Now they have sensors that do the same job and can establish an orbit in a couple of shots. This also means that the magnets and other gear in the beam tunnel is less irradiated and so acquires induced radiation much more slowly which is a Good Thing.

Yep. I love computers. I always find it amazing looking back at the history of accelerators. Considering how many sensors, computers and various other diagnostics we use it's incredible how much people managed to do before all that stuff was available. Even things built a decade or two ago look primitive compared to new accelerators, but they still managed to make world changing discoveries with hand built parts aligned by eye.

[athon]

Thanks for the responses, especially yours, Cuddles.

My concern was not so much 'how could this happen re. safety features'. Hell, it's mid-20th century Russia. I wouldn't be surprised if there was a machine built without safety in mind.

I guess I had in mind a large circular tube containing a vacuum surrounded by magnets - with a gap in the magnets or a break in the vacuum, the beam would be compromised. However I suspected there might be some arrangement where the beam exits the ring - I just didn't have any clue if that was the case.

Ta.

Athon

[Cuddles]

Thanks for the responses, especially yours, Cuddles.

My concern was not so much 'how could this happen re. safety features'. Hell, it's mid-20th century Russia. I wouldn't be surprised if there was a machine built without safety in mind.

I guess I had in mind a large circular tube containing a vacuum surrounded by magnets - with a gap in the magnets or a break in the vacuum, the beam would be compromised. However I suspected there might be some arrangement where the beam exits the ring - I just didn't have any clue if that was the case.

Ta.

Athon

This picture (http://www.diamond.ac.uk/Technology/default.htm) might help a bit. The exact design varies, but the basic ideas are always pretty similar. Generally, you first have a linac (linear accelerator) that sends a beam into a booster synchrotron which accelerated the beam further before the beam is injected into a storage ring. In the linked example, electrons stay in the ring and only photons come out to the beamlines, but in many cases, usually with proton machines, the particles themselves will be extracted.

This means that in a machine like the one in question, there are likely to be up to three transfer lines a beam could be sent down. It's hard to get many details about this, but I think at the time of the accident it just had a linac injecting straight into the storage ring, and a booster was only added later as an upgrade, and it did extract protons to fire at targets. Given the large dose, I think it must have been a fully accelerated beam that hit him, so it will almost certainly have been an extracted beam in a transfer line rather than beam from the linac. Given that we know a new extraction system was under construction at the time, that's certainly the most likely case.

[athon]

Wicked.

Thanks Cuddles. :)

Athon