My name is Sarvesh Sadana. I built a working fusion reactor in my garage. I also conduct research at Berkeley and run a 501 (c)(3) nonprofit. AMA!

Your fusion reactor -- how large is it, and how much power (both can be roughly) does it put out?

The SS chamber where the reactions actually happen isn't very large -- only about 6 inches in diameter. If you're including the vacuum system, the pumps, the power supply, etc., then it's much larger (mostly because I want to operate it from a distance for safety). If I had a space limitation, I could probably fit everything within 15 sq feet.

As for power- it produces almost nothing. The reason we have billion dollar fusion facilities such as ITER is because achieving more power than we put in is very, very hard. I put in about 1.5 kilowatts into the fusor (instruments, vacuum pumps, power supply), and get out probably less than a microwatt. Most of the power goes to accelerating the ions, heating up the chamber, and maintaining the vacuum.

Sarvesh

Wow, that's a Q-value of one billionth? Really does put some numbers on how hard it is.

As of 2017, the record for Q is held by the JET reactor in the UK, at 0.67. ITER was originally designed to reach ignition, but is currently designed to reach Q = 10, producing 500 MW of fusion energy with a 50 MW heating system. [wiki]

Yup.

There are ways to slightly improve the efficiency, though. The main source of power loss is due to the collisions with the central tungsten grid. Scott Moroch did some simulations to demonstrate this: https://imgur.com/JKe9Weg

Some devices, such as the polywell, get rid of the need for a central grid by using electromagnets to accelerate the plasma toward the center. It's very interesting stuff.

Sarvesh

Awesome work! As someone who just finished a PhD in plasma physics and fusion energy I just want to thank you for being so upfront and clear about the limitations of your reactor. The last thing this field needs is more articles in the vain of "This 17 year old just solved fusion power!". Good luck in the future!

Thank you! I agree completely.

My personal rule of thumb is to ignore all pop science. They screw it up. No exceptions.

What is your thought on Star Trek’s transporters? Are you still the same person after being transported or are you just a copy?

The logical part of me says that, because the transporter precisely replicates you down to the quantum level, you are the same person. The logical side of me would also say that sense of self isn't a meaningful construct, so it doesn't matter anyhow.

But then, I wouldn't exactly volunteer for transport. I suppose my faith in science only goes so far. Also, the thought of being beamed into space, molecule by molecule, is rather off-putting.

Sarvesh

Basically the transporter is a replicator. You could make replicas of yourself.

That's where I stand too. It's an exact copy of you, perhaps even with the same memories, but the original you was vaporized in the process.

Huge Trek nerd here. In the original canon, the first transporters did destroy the original and create a copy at the new destination. Eventually technology improved and they were able to convert your matter directly to energy, send out the energy as a beam, and recreate the original form.

http://memory-alpha.wikia.com/wiki/Matter_stream

And yet you still get various episodes across the various ST shows along the theme of duplicating a crewmember from transporter malfunctions etc.

Not to mention poor Tuvix :(

Are you the one they're talking about online when it says "power companies hate her!"?

I'm a guy, so I sure hope not!

Hey Sarvesh, Super interesting shit you have going on. My question has to do with how faculty members at the universities you have conducted research in react/interact with you--do they tend to give you respect? Assistance? Treat you lesser than or with some tinge of jealousy?

Great question!

Everyone I've spoken to and interacted with at Berkeley has treated me with nothing but respect and courtesy. They're all incredibly smart and nice people. (Though, I suppose I don't know what they say when I'm not there)

I was recently helping to train some Master students in the use of a certain machine. I also helped them with their research. They were exceptionally courteous and didn't even mention my age. I think they think that (somewhat undeservedly, to be honest) I'm some sort of wunderkind.

Although, because I'm under 18 and not actually enrolled in the university, I have little autonomy. I'm not supposed to operate any machine unsupervised, nor am I qualified to work in an experimental lab. It does restrict my research, as I'm not able to use any hazardous materials (nanoparticles, toxic solvents), but I try to make the best of it.

Sarvesh

I bet you can count on one hand how many 17yo are waiting for their 18th birthday so they can handle nanoparticles, toxic solvents, and other hazardous materials. Congrats on your achievements so far, and we will be excited to see your future endeavors!

<3

I'm surprised that you can legally build a fusion reactor in your garage. Or are you on a list now?

Also, what are the risks of such technology being used for nefarious purposes? I understand that fusion generates far less radiation, but it still produces some, right?

It's legal, yes. It doesn't have to be registered with the NRC because it's so small.

I'm sure that I'm on a list. I have a foreign sounding name, I'm building crazy nuclear stuff in my garage, I use Tor, and I'm a student pilot. I suppose it's a good thing I'm not Muslim. As a matter of fact, a few of the other members on the forum (fusor.net/board) were visited by the FBI.

It does produce radiation, yes. The only things that leave the chamber are neutrons (D+D --> 3He + N), x-rays, and the odd gamma ray. It's very hard to use it for nefarious purposes, because unlike fission, there's no risks of an overload or an explosion. I suppose one could use the neutrons to breed tritium with lithium 7, and use that in an improvised nuclear weapon. That would be highly dangerous and illegal though. Also, a fusor wouldn't be ideal for that purpose. Something like a PoBe neutron source would be far more consistent.

Hope that answers your question,

Sarvesh

Jesus, you’re producing neutron radiation and you’re comfortable with that?! What exposure rates are there (on contact and general area)?

They're minimal. Up against the fusor shell, the peak neutron flux was 4000 CPM. I myself am protected by the boron/paraffin shield, and I have a bag of boron around much of the rest.

Looks like a version of a Farnsworth-Hersch-Meeks fusor, is this correct? I'm used to them being in leaded glass Bell jars for maximum ooohhs and aaaahhhs also x rays.. but congrats! Would love to know more about the power supply, can you share some more info?

It is, yes!

The bell jar fusors, generally speaking, don't do fusion. The ion beams produced would cause them to implode. For a proper, research grade, neutron producing one, a stainless steel shell is crucial. It also helps to minimize the x-rays produced (as does the 1/8" lead, I suppose).

The power supply I'm using is a -30kV 32mA Glassman supply I found on eBay (PS/PG030N32-M92 to be precise). It appears to be a custom model from decades past. Unfortunately, this means that there are no schematics available, so I can't modify it to increase the voltage. Pics: https://imgur.com/a/c8IQx

The power supply wire is wrapped around a ferrite (I do that to absorb RF it creates) and connected to a Victoreen 200kOhm 50W resistor. That is connected to an HV feedthrough, and is attached to a tungsten grid.

I'm currently working on repairing a Spellman -70 kV power supply (DXM70N600X3547), but it's slow going. I'm also going to have to fabricate a cable and connector for that. With that, I should be able to dramatically increase the neutron output (and, I suppose, the danger level).

Hope that answers your questions! Feel free to ask any more regarding that or any other part of my fusor.

Sarvesh

That's awesome. Been wanting to build one forever. Been building Tesla coils for a bit and wanted to step it up. Started a 3d printing company so I have the resources too. If you ever need parts let me know. Keep on making awesome! Good work

You should! The forums are a great resource. Given that you already have a fair amount of HV experience, you definitely seem able (I had very little experience making and building things before).

Feel free to contact me if you ever have questions. I'd be happy to help!

Sarvesh

Don't you realize most kids your age are smoking pot and just talking about this stuff? Why be the rebel that puts the joint down and actually makes this thing? WTF? BTW...awesome job!

edit: nobody has a sense of frigging humor.

Thank you!

I really love building things. I'm not quite sure why, it's just who I am. You should give us teens a little more credit; we're not all bad!

Sarvesh

How much has your electric bill gone up since this requires an immense amount of power?

Thankfully, we have solar power.

It doesn't require that much power, though, because I don't operate it 24/7. I use them for only 20 minutes at a time, at most.

Equipment costs, though, are another story...

Sarvesh

Do you cover it out of your own pocket or did the University help you fund the equipment?

I had to cover it myself, unfortunately

How did you feel last month after achieving fusion? Were you aware of what happened? I think I’d start running around screaming if something so monumental happened for me! Congratulations, by the way!

Thank you!

While I was operating it, I was actually really worried that I would break something. The last time I tried pushing the voltage to fusion levels, I melted my grid!

It was quite worrysome to see the camera repeatedly fail due to x-rays (so I couldn't directly see what was happening), but I just hoped it was all good.

I did see quite a bit of interference on the oscilloscope, but saw a huge spike when I added the deuterium (the gas I use for fusion), which indicated that I had fusion. I was shaking a bit because, even though I knew I took every safety precaution, it was still extremely scary. 30000 volts is no joke!

It was quite cathartic to see that, after all this time, my results had been validated. I was really happy to see that it actually worked properly, and that I wasn't some crazy kook.

Hope that answers your question,

Sarvesh

Sorry if you answered this already, but how do you know it's achieving fusion? Is there a different output? Does it make a loud buzzing noise? Does a green light turn On? I'm curious what the output is to be a sign of success. Also, very impressive dude!

Great question!

In fact, neutron detection is one of the more difficult aspects of building one of these. Generally speaking, there are three approaches used at the low neutron flux we achieve. The first is the simplest.

There are small dosimeters available for purchase for around $400 by a company called Bubbletech in Canada. If it detects a certain amount of fast neutrons (each has a certain sensitivity), then a bubble is released. You can then reset it for later goes. A fair amount of fusioneers go this route, but I decided not to. They only work for about a year at most and are too simple for my taste.

The second route some more experienced fusioneers use is called neutron activation. When certain materials (silver, iridium, etc.) are exposed to neutron radiation, they become radioactive. This radioactivity can then be detected by a simple Geiger counter. I didn't do this, because it requires a relatively high neutron flux (at least 50k n/s).

The third and most difficult option is using a proportional counter. These are tubes filled with a certain gas (He-3 or BF3) and are biased to a certain voltage, generally in the 1200 volt range. Then, it is connected to an oscilloscope and computer (some use Nuclear Instrumentation Module [NIM] bins, but that's far more complicated).

When a neutron hits the counter, the oscilloscope has a small spike. Unfortunately, electrical noise is also picked up by the counter. I use software to discriminate the noise (and gamma/x-rays) from the neutrons. Essentially, I compare the amount of pulses I get from running the reactor with identical conditions without deuterium (and therefore, no fusion should happen) and with deuterium.

I'm trying to cut down on the noise, but I have statistically significant data indicating that fusion did indeed occur.

https://imgur.com/wDTwmsx Here is a picture of a background count using my setup

https://imgur.com/2iqQZZV And here is the graph obtained from one of my runs. As you can see, during minute 4 there is a sharp spike, whereas in minute 1 and 2 there are almost no counts.

Please let me know if you have any more questions,

Sarvesh

You mention the particles have a high velocity and then say around 30 million Kelvin which is a measure of temperature. Are you using some conversion over to the thermal velocity of the particles or was this a mistake?

Yes, it's a measure of thermal velocity. See http://www.fusor.net/board/viewtopic.php?f=42&t=10424

Hi Sarvesh! At what age did you start building your fusion reactor?

I started building it when I was 15. I'm 17 now.

Sarvesh

Is your garage radiated now? I know that JET has massive concrete walls around it to stop charged particles from harming anyone, including ceiling for planes.

Edit typo

It does produce some radiation, yes. However, thanks to the inverse square law (intensity is inversely proportional to the square of the distance), my neighbors and I are safe. Also, I have a fair bit of radiation shielding up. The wood box on the table has 1/8" lead shielding on both faces, and is filled with a mixture of boron and paraffin to absorb neutron radiation. Also, the entire shell is covered with lead as well, which is why it looks so ugly.

I recently attended a fusioneer gathering. They ran a fusor at higher voltages (more radiation risk) without any shielding. They also sold lots of radioactive stuff, like uranium, thorium, and radium there. The guy who hosted it even had a shed full of uranium ore. They claimed that there was more radiation from cosmic rays than from the sources, but it was still worrisome.

https://imgur.com/j4YqsBa

Have you calculated the the on-contact radiation levels in REM or have you taken rad levels? 1/8” lead is not much for gamma and boron doesn’t absorbe EM radiation.

I have two geiger counters, yes. They didn't read anything significant over background. The gamma ray is quite infrequent, as it only happens once ever 10000 fusions. That, coupled with the lead, the standoff distance (~15 feet), and the low exposure time (less than 5 minutes each) means that I'm not in any significant danger.

The boron is to absorb the neutrons, which have a somewhat high RBE.

Nuclear engineer, I understand how it works.

What are the gamma energies for these fusion events? How many average events per second? Are these Geiger counters on contact or 15 feet away or one each? What’s significant over background where you are? 50-100 cps?

The geiger counters are on me. I recorded 1000 CPM on a plane so I'd consider anything over that to be somewhat dangerous. There's a total of 3/8" of lead between me and the shell (front and back plate of the wood shield, and the shield over the shell).

The gammas are, generally speaking, insignificant.

Sarvesh

I understood some of these words. Your username has Dr in it, what doctorate degree do you plan on pursuing?

My mom actually calls me that, because she doesn't really understand what I'm doing either.

I definitely hope to pursue a PhD in something in physics, but I'm not sure what. I don't believe I want to do straight up nuclear physics, but high energy physics seems quite interesting. I haven't had much exposure to any specializations, though.

Sarvesh

Is your fusion reactor self-sustaining? That is, once it is running at maximum output, does it require any additional power to maintain the reaction?

I wish. If it were, I'd win the Nobel prize.

Unfortunately, real, feasible fusion power requires much more than the jury-rigged contraption I have in my garage. It requires constant electrical input of around -30kV at 10-30 mA.

Self sustaining fusion reactions are the dream of everyone who works in the field, because that would directly allow for commercial clean fusion power.

Sarvesh

What do your parents do for work?

My mom used to work in finance, and my dad used to be an engineer but now works in management.

They're not very technical people, to be honest, but they've supported me enough.

Congratulations on your success at achieving fusion and your other projects, truly incredible feats. I'm curious to know, what your thoughts on Starshot? Namely your thoughts on overcoming some of the challenges regarding mass, focused laser propulsion, etc, but any other thoughts as well! For me, the idea that we could get a glimpse of another star system during my lifetime is mind blowingly exciting.

Thank you for saying that!

It's definitely a very exciting prospect to say the least. I'm just not sure about the utility of it. The 100 million they asked for for R&D is worth it, for sure, but I don't believe it's worth it to actually build at the moment.

Also, one of the major problems I see is atmospheric scattering. Perhaps by making the lasers based in space (or on the moon) we can solve that and cut down on the power needed.

The cost is estimated to be in the billions, but I don't see the return. I think that money would be much better spent for the construction of something like a space fountain.

I love space exploration, but I think we should focus on refining our technology and making colonies in our own solar system before we start exploring the great beyond.

Sarvesh

Have you ever watched the film Primer?

Never watched it, no. It looks interesting though. I think I'll watch it sometime.

Fav colour?

Chrome

I've heard Helium is a depleting natural resource. Once it vents, it's so light it leaves the atmosphere into space and is lost. Do you produce it in any meaningful quantity (relative to power consumed)?

Yeah, there is a shortage of helium. It's scary and it sucks. Helium is absolutely critical for science as a cryogenic liquid.

Unfortunately, we can't make it at a significant rate via fusion, and especially not with my fusor. The best amateur fusors do fusion at maybe 100 million total fusions per second. It sounds like a lot, but that's only the number of atoms produced. 4g of helium has 6.02 * 10²³ atoms.

Sarvesh

how much did the fusion reactor cost to build and where did you get the funding?

In total, it cost around 6k (give or take).

Fortunately, it's much more of an investment than a waste of money. Many of the machines I've purchased were bought for parts and I fixed it up. I've also buy things extremely cheaply at flea markets and sell them for more. For instance, I recently bought an ion pump controller for $20 that's worth around $1600 used. Some people just don't know what they're selling, and it's great. More flea market goodies: https://imgur.com/a/qmRZo

In all likelihood, when I go to college, I'll likely donate the fusor there so I can continue to work on it. My parents will write it off on their taxes, and the net cost will probably only be a few hundred.

Sarvesh

What advice would you give someone who wants to start their own nonprofit?

I would start by identifying a certain issue you would like to focus on. Once that's done, you need to know why making your own 501 (c) (3) nonprofit is necessary, rather than simply volunteering or making a chapter of an existing one.

Next, if it is critical to make an organization yourself, you must ask yourself if you need it to be fully tax exempt and incorporated. You can do a lot of good in an unregistered one. The 501(c)(3) does add legitimacy, but it brings with it a ton of work. In my case, incorporating it was absolutely critical, as many organizations and individuals wouldn't work with us unless they could write it off on their taxes.

Then, if you've decided to incorporate it, be prepared for a lot of work. I would try to contact professionals who have experience dealing with all of the paperwork and regulations with nonprofits. Most corporations have a branch dedicated to philanthropy, so look around there.

After that, you have to make a board of directors, create a charter, and more.

Creating and running a nonprofit takes a ton of time and work. I prefer to be actually helping people rather than being involved with the bureaucracy behind your organization. When it's all said and done, though, you can do some great work.

Best of luck!

Sarvesh

Hi Sarvesh!

I imagine college is in your future. Any plans on where you'd like to go and what discipline you'd like to hone in on?

I'm really hoping to get into MIT or Caltech (if any admissions officers are reading this, please ignore that. I want to go to your school!). Unfortunately, my unweighted GPA isn't very good (3.72) because of a bad freshman year. I'm also applying to Harvey Mudd, Stanford, Princeton, and schools of that caliber.

I hope to pursue a degree in physics. I'm not quite sure which specialization yet, but I've always wanted to pursue something in physics. Also, if I go to a school where it's very easy to double major, I may also do something in Mechanical Engineering or Electrical Engineering.

Thanks for the question! Sarvesh

I mean...you're conducting research at Berkeley and built a fusion reactor in your garage.

You're gonna get into MIT, I'm pretty sure. You look into scholarships yet?

I can only hope the admission officers see it the same way.

I'm a normal guy that got deferred from MIT and I currently go to UMich. You're insanely smart, dude. Lots of potential. Good luck to you

I really appreciate that, thank you!

What are your parents' occupations?

Finance and business. They're not technical people.

And people thought a kid building a clock in a pencil box was alarming?

I'm sure that if the HOA found out, they'd be less than happy.

Anyway, I've brought more dangerous things than a simple clock to school. I think he only got in trouble because it looked dangerous, not because it was dangerous.

How would someone get started making their own fusion reactor at home?

I don't think it's wise to jump headlong into making a full fusor. I would start by first going to the forums (fusor.net/board), and learning more about all of it.

Then, I think a good first step would be to build a small "demo fusor". These are small devices that make a beautiful plasma in a low vacuum. It will help you acquire the skill you need (vacuum, high voltage) to actually build one.

Make Magezine has an excellent guide to building one

To be clear, this does not do any nuclear fusion. You would need deuterium, a much higher voltage power supply, and a stainless steel shell to do that.

Best of luck!

Sarvesh

How can i be like you? Im 16 and people like you just blow my mind. I want to be a scientist (no joking nor childish stuff i legit want to do research) but im always uncertain on what i will actually do with my life. So i wanted to ask, how did you become like that? How did you manage to figure out what to do? How did you get your resources? How did you learn what you know?

A passion for science is absolutely critical to becoming a scientist, and you seem to have that. I would say not to become like me; building jury rigged projects in the garage isn't scientific research.

If I were you, I would try to get involved with research at a local university. Often, professors are more than happy to take an ambitious young researcher under their wing. To do that, you should should first identify your chosen field of study. Then, search through the literature (sci-hub may will help you access paywalled info) for an interesting avenue of research.

Read the literature, find a very specific research topic, and then contact professors who work in that field and ask them if you can do that. Many will say no, but some will say yes.

Also, keep in mind that it's not critical to know what you're doing at this stage in life. Most successful scientists don't start doing their research during undergrad or even in grad school.

Please, don't hesitate to contact me if you need help.

Sarvesh

How much did it cost? I wanted to build one while I was a teen but the potential cost to my family was what pushed me away.

I'm sorry to hear that. It cost around 6k. I would think that the overall benefit (scholarships, etc.) plus the fact that you can sell the stuff back would make it worthwhile.

Sarvesh

All I see here is "my parents have a lot of money so I'm following the instructions from other people." What is really that impressive about all this besides the the problem solving and memorization required in building complex Lego sets? This honestly just seems like the same thing as someone else your age building a rocket capable of photographing the earth's curvature. Sure, they could put a lot of esoteric terms and measurements in the description that they've memorized, but by this point in history it's really just an absurdly expensive construction set.

I never claimed that it was an impressive accomplishment, only that it is uncommon.

It involved far less cookie cutting than you might think. The basic principles of operation are firmly established, yes, but I've had to fully design and build every single part of the system. It's much more of an engineering project than true scientific research (though, I'm using it as a platform for plasma research).

Sarvesh

Anyone can build a fusor, there's a 14 year old on fusor.net who did it faster. Why did you neglect to study things like the rules of capitalization before filling out this application for /r/iamverysmart?

Edit: you have no doctorate, not even a high school diploma, but your username makes it clear that you are deluded about your limited accomplishments.

The youngest fusioneer is 14 years old. A neutron producing fusion reactor is not the same as a bell jar demo fusor.

[deleted]

If you're referring to the bureaucracy, then definitely yes. I helped order a machine for the lab months ago (August), and only now did the purchase get approved.

Sarvesh