New record for fusion

On Friday, Sept. 30, at 9:25 p.m. EDT, scientists and engineers at MIT’s Plasma Science and Fusion Center made a leap forward in the pursuit of clean energy. The team set a new world record for plasma pressure in the Institute’s Alcator C-Mod tokamak nuclear fusion reactor. Plasma pressure is the key ingredient to producing energy from nuclear fusion, and MIT’s new result achieves over 2 atmospheres of pressure for the first time.
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Pressure, which is the product of density and temperature, accounts for about two-thirds of the challenge. The amount of power produced increases with the square of the pressure — so doubling the pressure leads to a fourfold increase in energy production.
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During the 23 years Alcator C-Mod has been in operation at MIT, it has repeatedly advanced the record for plasma pressure in a magnetic confinement device. The previous record of 1.77 atmospheres was set in 2005 (also at Alcator C-Mod). While setting the new record of 2.05 atmospheres, a 15 percent improvement, the temperature inside Alcator C-Mod reached over 35 million degrees Celsius... The plasma produced 300 trillion fusion reactions per second and had a central magnetic field strength of 5.7 tesla. It carried 1.4 million amps of electrical current and was heated with over 4 million watts of power. The reaction occurred in a volume of approximately 1 cubic meter (not much larger than a coat closet) and the plasma lasted for two full seconds.

Source: MIT.edu news, Oct. 14, 2016 - New record for fusion.

The sub-headline reads: Alcator C-Mod tokamak nuclear fusion reactor sets world record on final day of operation.

Yeah! Actual news from an actual news site with technical details and everything! Two seconds is very respectable as is the 8 T magnetic field strength. This reactor is not meant to put energy on the grid but do experiments exactly this: plasma research. The Wendelstein 7-X is also a plasma research device. This research has to be conducted to have proof of concept (PoC) prior to building a real reactor. The research fusion devices share data with each other to prevent other researchers from making mistakes. They also collaborate on each other's projects. They design parts for other reactors, they test materials, share physical samples, validate results, etc. This is real science.

The last day of operation was due to the budget coming to an end. I would hope somebody would decide, "Hey, that is neat! Here is more money" but that is the way of national funding. And that is also the why of private industry getting into the fusion business and research.

Oddly enough, I reading this Wikipedia entry when I ran across this news story: Plasma-facing material, as I came across a material I was not certain of: beryllium. Those "300 trillion fusion reactions per second" will create fast and slow neutrons zipping around in the reactor because they are not affected by the magnetic fields. Which means they will collide with the reactor walls facing the inside of the evacuated reactor chamber. The "first wall" as it is called has to stand up to these reactions as well. The best idea for first wall material is liquid lithium but beryllium can also be used. This material is being tested for use in the ITER device.

Yeah! Way to go MIT! 2.05 atmospheres! The article says that may stand until ITER is up and running.

Another step towards a nuclear fusion future!

Scientists, students, and faculty from the Alcator C-Mod team will discuss fusion, the pressure record, Alcator C-Mod, and the high-field approach at an Ask Me Anything Session on Reddit on Thursday, Oct. 20

(same source)

Hey! They get an AMA on Reddit?!! *shakes fist*

Because it is on my mind, I would ask about their first wall material.

BTW, the next device in MIT's sights is their ARC reactor (Affordable Robust Compact) which is designed to be modular in construction, uses stronger superconducting magnets, and repeatable so they can make multiple ones.

[Sorry but I am only around for the next five. I will check in tomorrow and answer as many questions as I can. -TEOT]



Hey, do not be afraid to ask questions! This is dorky, science stuff about my fanboy topic. So share how you feel about fusion. Does the story interest you or not? Too techie? Me...

Cool news....but I thought most reactors already use Nuclear Fusion and we're trying to get to Nuclear Fission. I guess I have it backwards.......?

originally posted by: lostbook
Cool news....but I thought most reactors already use Nuclear Fusion and we're trying to get to Nuclear Fission. I guess I have it backwards.......?

Right. You have it backwards. Fission happens in any chunk of transuranic material. Fusion, not so much.

a reply to: TEOTWAWKIAIFF
It's nice to see a milestone reached, but why is it that 4 decades ago people were talking about commercial fusion power being 5 decades away and now 4 decades later, it still seems like it's 5 decades away?

I got a little excited about Lockheed's portable fusion reactor at first, but I found this update rather disappointing, as it suggests they aren't nearly as far along as I was led to believe by prior announcements:

Lockheed Still Supporting Portable Nuclear Generator

a reply to: lostbook

Fission is what we are currently doing-splitting the atom.

Fusion combines particles to release energy. The simplest one is using hydrogen isotopes (deuterium and tritium), heating the gasses up to really high temperatures, under the right pressure and density, the two tiny particles combine to make helium. Right now, they can make fusion happen but it uses more energy than it produces.

The high temps (100 million degrees) need to be kept off the reactor walls so that is done with super conducting magnets. This announcement is stating they got up to 2.05 atmospheres at 35 million degrees all of that hot gas was contained by 8 Tesla field strength magnetic coils for a grand total of 2 seconds.

Once density is large enough, once the temperature is hot enough, the point called 'ignition' will be reached. Then we will have the worlds first self-sustaining nuclear fusion reaction. The sun truly trapped in a bottle. And all zero CO2 emissions.

a reply to: TEOTWAWKIAIFF

The sun truly trapped in a bottle.

Which will be used to...boil water. More or less.

a reply to: Arbitrageur

The superconducting magnets reached a plateau back in the 80's. That is why the ITER reactor is so huge-they are using 1980s magnets. They can only create enough plasma to generate power by making the amount larger with lower magnetic strength magnets.

MIT's ARC uses newly created rare earth barium copper oxide (REBCO) superconducting magnets that will a little more than double the confinement strength. And like the article says that scales by four the ability to confine. For this very reason I am excited about what may be coming out next!

[ETA: Not "newly created" they are relatively new. But they are also an off the shelf product now instead of one off]

[EAT II: Lockheed's T-4 has created its first real plasma which is something nice to see!]

a reply to: Phage

Until the proton-Boron reaction is perfected. Yes, heat water to turn a turbine. But we already have turbines... so just chuck out the coal and gas plants and save the planet!

So, this "news" comes out right after the $ stops on Sept. 30th? Seems odd that this huge milestone was just reached, to me anyway.

While Alcator C-Mod’s contributions to the advancement of fusion energy have been significant, it is a science research facility. In 2012 the DOE decided to cease funding to Alcator due to budget pressures from the construction of ITER. Following that decision, the U.S. Congress restored funding to Alcator C-Mod for a three-year period, which ended on Sept. 30.

a reply to: TEOTWAWKIAIFF

a reply to: seasonal

Maybe, but more likely, the culmination of their efforts was scheduled to coincide with the end of funding. Or at least the culmination followed by analyses and publication.

a reply to: TEOTWAWKIAIFF

Btw, thank you for posting awesomeness! Perhaps TEOTWAWKI (a world without fusion reactors) is coming in our lifetimes after all - let's hope!!

originally posted by: Bedlam

originally posted by: lostbook
Cool news....but I thought most reactors already use Nuclear Fusion and we're trying to get to Nuclear Fission. I guess I have it backwards.......?

Right. You have it backwards. Fission happens in any chunk of transuranic material. Fusion, not so much.

Thanks

a reply to: dogstar23

Maybe, but I tend to follow the money. It's always, always, always about $ and power.

Are you saying this doesn't apply here? I'd like to believe that.

a reply to: seasonal

*sigh* Yes, and a couple weeks after it happened (news release Oct. 14). I would think that a fusion milestone would be better represented especially from an institution that is trying to drive non-CO2-emissions as their forte.

a reply to: dogstar23

Yeah, but then again, everything will be alright! The funding cycle seems to be (tin foil hat time) to cast out an anchor on what has already happened. I have pretty much convinced myself that Lockheed has a CFR on their hands because the gubermant wanted to shut down the national helium reserve. The only reason for that is if you have an abundance of helium... the by product of fusion. My own take on the whole situation.

a reply to: lostbook

I was thinking of making a "mega thread" on explaining what-how fusion works. Mostly because there is no thread here that does so. Do not be discouraged about the topic because this is something everybody needs to understand. I will probably keep tagging this thread on all fusion advancements.

Heck, the only reason I stopped lurking here was because the W7-X made its first hydrogen plasma and nobody had posted the update! This is cool science and someday we will end most of our conflicts on the surface of the planet because there will be an abundance of energy (my inner hippie talking there).

Sorry but I am stupid in some ways and assume that everybody knows what the h3ll I am talking about!

I am wondering if these tests could accidentally turning the planet into a second star if it goes out of control...

a reply to: SaturnFX

The density of the plasma is such that if it does "get out of control" all they have to do is drop the temps down from 100 million to... no longer hot enough for the reaction to happen.

The deuterium is typically in frozen pellets so they would just shoot a couple of those into the plasma without adding more energy into it. About the only danger is radioactive tritium floating about.

That is one of the nice things about fusion! The other is that the embrittlement of the reactor's walls will only last about 100 years so at that point you can recycle the whole reactor vessel (the free neutrons impact the reactor like in fission but does not last long--the half life of the radiation is not the same as in fission).

a reply to: TEOTWAWKIAIFF

Any thoughts about a micro-mini black hole fusion reactor?

Where the two outer magnetic shields [surrounding the black hole's event horizon] are used to create fusion plasma, by having one shield press the deuterium atoms against the other shield with extreme pressure till the fusion reaction occurs.

The containment shield contains seawater, which is a neutron barrier from fusion reactions.

I’ve always thought that the basic bugbear of ‘Fusion’ energy – apart from the 50 year wait - is the conversion of thermal energy into a useable form ie; Electricity.
Fission thermal energy is easy enough; the reaction is dependent on neutron cascade and preventing a thermal runaway or nuclear excursion. Principally, this is achieved by control rods, neutron moderation and coolant. Coolant goes to heat exchanger and resultant thermal imbalance drives a turbine.
How in the world they will ever create an ongoing fusion reaction that emulates fission is beyond me. For it seems that to achieve yield (thermal energy transfer) the fusion state must be all but shut down, and to start it up again costs so much [energy] that break-even is all but impossible.

a reply to: Erno86

Black holes are space-time/gravity related. The singularity is where the fabric of space-time is so warped that when light passes the even horizon it is not fast enough to escape. Man-made nuclear fusion cannot use gravity to help control the reaction which is why the temperatures have to be hotter than the sun.

The nuclear fusion reaction can only occur when the electrons are stripped away from the hydrogen isotopes. This is due to quantum mechanics--no two electrons can occupy the same state in a molecule. So the two gasses are heated to create a plasma state (like that "lightening novelty globe" where it follows your fingers when you touch it). The inner plasma (where the actual fusing is to happen) is heated up by "neutral beam injectors" which can be thought of like high intensity microwaves. The magnetic shield keeps the plasma from touching the confinement vessel so the heat does not drain out.

Seawater is a source for deuterium and is not actually used in the reactor.

a reply to: Cinnamon

A thermal blanket could be used. The thought being a lithium thermal blanket would intercept the fast neutrons zipping about, creating energy (heat) and a new tritium particle. The tritium is then trapped by the magnetic fields and the radiant heat can be thermally exchanged using which ever coolant method you desire. The problem is the first wall will not last as long because the neutrinos have go through that first. And the size of this blanket may have to be feet thick and very heavy.

The better method is to use liquid lithium on INSIDE of the containment vessel (within the vacuum chamber itself). A thin stream of liquid lithium is dripped (just saw the other day one version, we are talking 10 nm size holes, so a pretty small amount) to coat the inside first wall. When neutrinos hit that a tritium particle is produced and quickly trapped by the magnetic fields. The lithium is recirculated a few time then replaced with a new supply. The hot lithium that was just removed is sent through a thermal exchange unit ready to be sent back in. The first wall lasts longer in this version.

The "liquid lithium limiter" has been tested out in China's EAST reactor and has run for over ten minutes. Princeton Plasma Lab created the LLL (pretty sure it was them) and they are being tested out in other reactors.



For those that wish to understand how a nuclear fusion reactor would work check out the fine folks at HowStuffWorks and their overview article.

Link: Science - HowStuffWorks.com: Nuclear fusion reactor.