CERN scientists confine antihydrogen atoms for 1000 seconds

May 04, 2011 by Bob Yirka report
(a) A schematic view of the ALPHA trap. Penning trap electrodes are held at ~9 K, and have an inner diameter of 44.5 mm. A three-layer silicon vertex detector surrounds the magnets and the cryostat. A 1 T base field is provided by an external solenoid (not shown). An antiproton beam is introduced from the right, while positrons from an accumulator are brought in from the left. (b) The magnetic field strength in the y-z plane (z is along the trap axis, with z=0 at the centre of the magnetic trap). Green dashed lines in this and other figures depict the location of the inner walls of the electrodes. (c) The axial field profile, with an effective trap length of ~270 mm. (d) The field strength in the x-y plane. (e) The field strength profile along the x-axis. Image credit: ArXiv paper (see ref. below)

( -- Seventeen minutes may not seem like much, but to physicists working on the Antihydrogen Laser Physics Apparatus (ALPHA) project at the CERN physics complex near Geneva, 1000 seconds is nearly four orders of magnitude better than has ever been achieved before in capturing and holding onto antimatter atoms. In a paper published in arXiv, a team of researchers studying the properties of antimatter, describe a process whereby they were able to confine antihydrogen atoms for just that long, paving the way for new experiments that could demonstrate properties of antimatter that until now, have been largely speculation.

The process works by cooling the antiprotons that when combined with , are used to make the antihydrogen, which reduces the energy in the resulting and allows for more of it to be confined in a magnetic trap, and then held there in a cloud for a period of time.

One of the big questions in physics is whether antihydrogen occupy the same as hydrogen; others of course want to know how it reacts to gravity, as some have speculated that antihydrogen might actually fall up, or behave in other unexpected ways. The experiments going on at CERN might just answer both those questions, and more.

The idea of the specialness of antimatter has become a fixture of modern science fiction books, magazines and especially television and movies, creating in the public mind an oftentimes distorted image of what harnessing antimatter might bring. Thus, any new advances such as those happening at tend to incite headlines that invite even more speculation.

At any rate, in the experiment, the researchers were able to trap 309 antihydrogen atoms, up from the previous best of just 38, which means the team is learning to both capture more of them and to hold on to them longer before collisions with various trace gasses causes them to be annihilated, or in some cases to become energized enough to escape the .

Up next for the ALPHA team are plans to cool a small bunch of antihydrogen atoms in such a way as to allow them to watch as it either rises or falls due to gravity, thus answering one of the more exciting questions regarding antimatter, in perhaps just the next few months.

Explore further: Uncovering the forbidden side of molecules

More information: Confinement of antihydrogen for 1000 seconds, arXiv:1104.4982v1 [physics.atom-ph]

Atoms made of a particle and an antiparticle are unstable, usually surviving less than a microsecond. Antihydrogen, made entirely of antiparticles, is believed to be stable, and it is this longevity that holds the promise of precision studies of matter-antimatter symmetry. We have recently demonstrated trapping of antihydrogen atoms by releasing them after a confinement time of 172 ms. A critical question for future studies is: how long can anti-atoms be trapped? Here we report the observation of anti-atom confinement for 1000 s, extending our earlier results by nearly four orders of magnitude. Our calculations indicate that most of the trapped anti-atoms reach the ground state. Further, we report the first measurement of the energy distribution of trapped antihydrogen which, coupled with detailed comparisons with simulations, provides a key tool for the systematic investigation of trapping dynamics. These advances open up a range of experimental possibilities, including precision studies of CPT symmetry and cooling to temperatures where gravitational effects could become apparent.

via Technology Review

Related Stories

Antimatter atoms ready for their close-up

Feb 07, 2011

Two international teams of physicists, including RIKEN researchers (Japan), have trapped and manipulated atoms made out of antimatter, in milestone experiments that should help to reveal why the substance ...

Coldest Antimatter Ever Produced

Jul 06, 2010

( -- Physicists working at the CERN nuclear research lab on the border of Switzerland and France have generated the coldest particles of antimatter ever recorded.

Antihydrogen trapped for first time (w/ Video)

Nov 17, 2010

( -- In the movie Angels and Demons, scientists have solved one of the most perplexing scientific problems: the capture and storage of antimatter. In real life, trapping atomic antimatter has never ...

Recommended for you

Uncovering the forbidden side of molecules

Sep 21, 2014

Researchers at the University of Basel in Switzerland have succeeded in observing the "forbidden" infrared spectrum of a charged molecule for the first time. These extremely weak spectra offer perspectives ...

How Paramecium protozoa claw their way to the top

Sep 19, 2014

The ability to swim upwards – towards the sun and food supplies – is vital for many aquatic microorganisms. Exactly how they are able to differentiate between above and below in often murky waters is ...

User comments : 39

Adjust slider to filter visible comments by rank

Display comments: newest first

3.2 / 5 (10) May 04, 2011
Still got a ways to go guys, but an order of magnitude in amount and 4 orders in length of time is a pretty big jump in anything.
5 / 5 (11) May 04, 2011

Wow, 18 minutes, that's impressive as hell. 18 minute, 20 years, makes no difference at this point.. 18 minutes, 1000 times longer and larger than ever, indicates there is a way to capture it indefinitely, for all intents and purposes.
4.7 / 5 (6) May 04, 2011
maybe ahead of the music, but if it turns that antimatter would have antigravity it might explain where the missing antimatter in the universe is, large clumps could have been repelled from matter during the big bang to form a spatially seperated universe
4 / 5 (6) May 04, 2011
maybe ahead of the music, but if it turns that antimatter would have antigravity it might explain where the missing antimatter in the universe is, large clumps could have been repelled from matter during the big bang to form a spatially seperated universe

Unlikely. The difficulty is that matter / antimatter annihilation produces distinct gamma ray signatures. While its barely possible that these emissions are faint and have not yet been detected, there would be a distinctive glow around any significant collection of anti-matter. Can you say 'Stick out like a sore thumb'?
3.7 / 5 (3) May 04, 2011
Ah yes, if antimatter "falls up" that would be a spectacular find, and perhaps very useful.

Though if it requires 1-1 ratio to achieve gravity "neutrality", a flying object as yet to be identified would have to be half composed of antimatter, making it's crash on earth quite spectacular if extraordinarily detrimental.

Maybe the dinosaurs encountered such a craft... oh the speculative possibilities!
2 / 5 (4) May 04, 2011
If antimatter were repelled by gravity, anti-atoms would also repeal each other.
I doubt that gravity would work differently on antimatter. We would be able to differentiate between acceleration and gravity, and the entire building of physics would crumble.
1 / 5 (2) May 04, 2011
Wow, that is very close minded. Cant be true because we don't understand it has been shown false time and again throughout history.
1 / 5 (7) May 04, 2011
Sounds great. But what is it good for?
1 / 5 (2) May 04, 2011
maybe ahead of the music, but if it turns that antimatter would have antigravity it might explain where the missing antimatter in the universe is, large clumps could have been repelled from matter during the big bang to form a spatially seperated universe

Unlikely. The difficulty is that matter / antimatter annihilation produces distinct gamma ray signatures. While its barely possible that these emissions are faint and have not yet been detected, there would be a distinctive glow around any significant collection of anti-matter. Can you say 'Stick out like a sore thumb'?

Rather like the 511 KeV "haze" surrounding the Shapely Center. (As if (m)any here even know what the Shapely Center is).
5 / 5 (2) May 05, 2011
That's Shapley Centre ... The Sapely Center is a women's gymnasium.
1 / 5 (12) May 05, 2011
THE scientists who brought you the device that may one day destroy the world by sucking it into a black hole have a whole new terror to reign upon you.

Everyone knows gravity attracts matter it's one of the reasons why we stick to the ground.

But how does gravity feel about antimatter?

According to the scientists at CERN the same organisation responsible for the Large Hadron Collider we're about to find out.
not rated yet May 05, 2011
If anti hydrogen falls up, why wouldn't an anti proton fall up? It would be great though.
2 / 5 (1) May 05, 2011
I'm far more interested in learning how to trap enough of this anti-matter to fuel a spacecraft / starship. With (if I recall correctly) approx. 50% of mass as antimatter fuel, and a system to collect matter fuel en route, feeding both into a huge sodium chloride crystal parabolic reflector (gamma ray reflector), we could put a starship on Proxima centuari (4 light yrs away), stop it for 2 years there, and bring it back in 18 earth-years total trip (16 yrs for the travelers).
5 / 5 (4) May 05, 2011
16 yrs for the travelers

Except that anyone going at that sort of speed (or even an appreciable fraction of it) would be instantly fried by all the hard X-rays produced from collision with the occasional stray atoms in space
2 / 5 (1) May 05, 2011
X-RAYS do not generally pass through metal. Also, free space tends to have 1 or 2 atoms per cubic meter. Even going at the speed of lite, the magnitude wouldn't compare to that of a chest x-ray. I beleive this to be a non-issue, but this isn't my field, just a hobby.
not rated yet May 05, 2011
I know there is a major concern for radiation poisoning in deep-space travel. And, you're right, gunslinger, x-rays aren't the problem... If I remember right, it's Gamma that is the culprit out there. Unless we can come up with some sort of composite material that will absorb most or all radiation types, we'll have to wait until we develop a system of electro-magnetic shielding that will protect the craft much in the same way the Earth protects us. The problem, of course, is a power supply that can generate enough power for the whole ship. Now, a matter-antimatter reaction engine would probably produce enough energy to drive engines, shielding, all the electronics, and still have enough power left over to keep their coffee warm.
not rated yet May 05, 2011

If antimatter were repelled by gravity, anti-atoms would also repeal each other.

you are assuming i think that these anti atoms would also create a normal, classical, gravity field when they would if it is in fact demonstrated act in a totally opposite fashion.... why?

about shielding ---

the earth is protecting us -- but its really that the atmosphere is so thick that 99% of everthing is absorbed before it gets to the ground -- cosmic rays are replelled by a magnetic field buts thats about it -- I THINK -- feel free to correct me
5 / 5 (1) May 05, 2011
Everything I've read/seen says that if our planet's magnetic shield failed, our atmosphere would be burned away by the solar winds.
not rated yet May 05, 2011
Everything I've read/seen says that if our planet's magnetic shield failed, our atmosphere would be burned away by the solar winds.

I beleive this to be true, however, we aren't talking about it being instantanious, rather, over millions of years.

My understanding is that the EM field protects us from charged particles only. It probably also protects us from cirtain frequencies of EM waves, but not all. There probably would also be a feedback effect where as our atmospher is erroded, atmospheric pressure is reduced and volcanic activity is increased as would water vaporization.... which would probably extend the degradation further.

it's Gamma that is the culprit out there.

I beleive this to be more accurate, but I think they are really talking about gamma ray bursts, the chances of which hitting a space craft is negligable. I don't think we are too worried about other trace types of gamma rays.

I think we should have reach proxima 40 years ago, we r slow.
5 / 5 (3) May 05, 2011
The other big problem they're worried about is micrometeroids... basically dust particles flying around so fast that they punch holes right through the spaceship and anything or anyone inside it. NASA even has a group devoted to studying protection technologies for spacecraft:
5 / 5 (4) May 05, 2011
Yeah, that is the biggest external danger I see, meteorites (micro). But I think that is a solvable problem. I thought about a solution: Imagin the hull of the spacecraft is a cylinder. Now take that cylinder and stick it inside a slightly larger cylinder. Inbetween the two cylinders, put a goopy material, possible one that hardens very fast when exposed to the cold of space. So, the idea is that the inner hull slowly rotates (maybe 1 Rev per year). If a meterite punctures the outer and inner hull, then the rotation is increased for a split second so that the holes on the inner and outer hull no longer align and, in effect, the hole is pluged. You could also slide the inner hull so that the holes do not align again on the next revolution. Also, the goopy stuff will plug the holes and harden, but the main idea is that your unaligning the holes.

1 / 5 (1) May 05, 2011
Gunslingor, one hole, and the self sealing membrane would glue the inner shell to the outer shell. That is unless you keep it under pressure so that it seeps out of the puncture to seal on the outside of the craft?
not rated yet May 05, 2011
The metiorites we are talking about are millimeters in size, it would be easy to maintain pressure for a few milliseconds. Plus, we are talking hi teach custom tuned NASA sealent that could be like 10-W50,000,000. Each hull could be inches think. Anyway, multiple hulls is the way to go, figure out another way..
5 / 5 (4) May 06, 2011
cosmic rays are replelled by a magnetic field buts thats about it

Cosmic rays (X-rays, gamma rays) are photons which don't really care about magnetic fields. Neither do electrically neutral objects (non-ionized atoms, dust particles, etc. ) Only charged particles (e.g. free electrons and ionized atomic nuclei) are affected by magnetic fields in their path.

Here's a paper on the dangers of relativistic spaceflight:

But that is only a look at the average dangers. At that speeds your 'look ahead' and evasion capacity is virtually nil. Even if you 'only' go at 0.1c :
One interstellar object that is slightly larger than a grain of sand will spell the end of the mission

and at 0.1c you'll be travelling 40 years to reach the nearest star (which isn't of much interest since no planets have been found there yet)
not rated yet May 08, 2011
Speeds close to the speed of light are impractical, even in an "ideal" anti-matter rocket engine. Excluding some yet-to-be-discovered technology, such as warp drive, the costs of going faster increase more rapidly than the benefits, even in an ideal antimatter rocket engine.

Even if you ignore relativity, it would take exponentially more fuel in a real antimatter rocket to go to 0.8c than it does to go to 0.1c.

In fact, contrary to what most people think, "relativity of mass" really doesn't become the dominant limiting factor until somewhere around 0.9c.

Before about 0.9c, classical Newtonian mechanics remains the dominant limiting factor for interstellar travel, namely in the form of the rocket formula due to the mass of fuel plus mass of propellant problem.

In an anti-matter rocket, you still need a huge amount of propellant, and it still works on a formula of order greater than 1, just not as bad as the chemical rocket formula.
not rated yet May 08, 2011
Even in an ideal antimatter rocket, it would take 8 times as much energy to go from rest to 0.8c, or to stop on the other end, as it would to go from rest to 0.1c, or to stop on the other end.

And you don't even get a 1 to 1 cut in the duration of flight by increaseing maximum speed, because the faster your maximum speed the longer you must accelerate, so it takes longer to get to top speed. You can't accelerate any faster than maybe 10m/s to maybe 15m/s else your crew will die.

AT 10m/s^2 acceleration, you need to burn the engines for ~278 days to reach 0.8c, and again for that long on the other end to stop on the braking phase.

So even with a top speed of 0.8c it would actually take around 5.52 years to reach proxima centauri, since you spend about a quarter of the time accelerating at less than top speed, or braking on the other end.

Which ultimately means that even with ideal antimatter engines, you spend 8 times the resources to achieve not much better flight time...
not rated yet May 08, 2011
One interstellar object that is slightly larger than a grain of sand will spell the end of the mission

At impact velocity of 0.1c, a 1 milligram object has a kinetic energy equivalent to the energy released in burning 3.4 gallons of gasoline in the pressence of oxygen.

Only in a collision this energy would be released instantaneously.

It seems likely that this collision would produce a fireball and either destroy or severely damage the hull of the ship, even if you don't count secondary explosions of on-board systems such as oxygen tanks.

In the case of an anti-matter rocket, any damage whatsoever to the fuel tanks would be instant death by annihilation.
not rated yet May 08, 2011
At ~0.87c The kinetic energy of a proton hitting the front of a ship would be about the same as the energy released in a proton-anti-proton annihilation at rest. Thus serving as negative thrust in excess of the mass-energy of your fuel source...

So, for example, if you were hoping to collect ordinary matter hydrogen to annihilate with your antimatter, it won't work.

At this point, 0.87c, the drag force the captured hydrogen atom produces will equal the maximum mass energy released by annihilating that atom with an anti-hydrogen atom, EVEN in an ideal antimatter rocket.

And of course, real antimatter rockets are less than ideal, since you must spend significant amounts of energy on the containment system, and since no more than about 50% of the energy is available to do work anyway.

By the time you get to 0.87c, you will definitely have negative net thrust from the interestellar gas medium, even if you can somehow magically survive colliding with said gases...
not rated yet May 08, 2011
The reason that last statement is true is because the relativistic mass has increased to slightly more than double the rest mass.

So when you plug in the kinetic energy formula, you get.

Ek = (0.5)*M*V^2

But M' = 2.028M when V = 0.87c

So then you have:

Ek = (0.5) * (2.028M) * 6.8121E16 m^2/s^s

Ek = 6.907E16 Joules (assuming M is a kilogram)

By comparison, the mass energy of annihilating a kilogram of matter with a kilogram of antimatter is:

1.8E17 joules

Ok, so sue me, my guesstimate of the equilibrium velocity is off by a couple hundredths of c, but you get the point.

Ok, in an ideal antimatter rocket, the actual equilibrium point would be somewhere between 0.97c and 0.98c.

In a "realistic" antimatter rocket, the equilibrium point is more like 0.75c.

See, when you consider real world obstacles and engineering, the limits are always far lower than ideals.

When you consider structural integrity, the limits are far lower, maybe 0.1c...
not rated yet May 09, 2011
"You can't accelerate any faster than maybe 10m/s to maybe 15m/s else your crew will die."
-Well, at least we solved the gravity plating problem =).

-Anyway, I think no one here doubts that it is mans destiny to reach the stars, it will get easier... That being said, we shouldn't wait for it.
5 / 5 (1) May 09, 2011
Those interested in the prospects of interstellar travel may be interested in finding a copy of "Can Star Systems Be Explored?: The Physics of Probes" by Lawrence B. Crowell:

Dr. Crowell is a published theoretical physicist interested in astrophysical topics related to black holes and quantum gravity, among others (he also has a book out concerning quantum fluctuation of spacetime: )

As a regular poster at Universe Today, he regularly comments on many aspects of interstellar travel. He currently has some interesting comments on interstellar travel in the article "Update on Gliese 581ds Habitability": http://www.univer...comments

Some good stuff (and minus the "woo" factor so commonly found on some blogs). Highly recommended.
3 / 5 (2) May 09, 2011
wrt practical limits on the speed of interstellar craft Dr. Crowell notes(from my last link to Gliese 581ds habitability, above):

The practical limit for [current] propulsion systems is .1c. Fusion is the only plausible propulsion system now, and that is still a technical TBD. To get beyond .1c with a propulsion system on the craft will require some direct conversion of mass to energy. The obvious one is antimatter, but as yet we have no way of producing large amounts of antimatter. The understanding of quantum field theory as it connects to gravity, or quantum gravity, might give rise to physics which permits the violation of baryon numbers. If so then we might be able to convert matter into energy. However, that is what might be called exotic physics and technology. This would be a relativistic rocket, which I do discuss at some length in my book."
not rated yet May 10, 2011
Thanks most of you for confirming my proposition. I did this as an off-the-cuff presentation at an undergrad tutor session at UofT physics in 1969 and haven't re-visited it since as no possibility of trapping significant masses of antimatter were even on the horizon, so my recall of the precise numbers may be off but those are close.

Proposed dangers of acceleration are not a problem, as the craft is designed to accelerate outward at 1 g for 4 years, then turn around and decelerate at 1 g for the next 4 years.

Agreed, shielding will be the problem, as well as finding some usefull destination within the restricted range of such a craft
not rated yet May 10, 2011
On the issue of "insufficient energy due to capturing H2 atoms en route", not the case, as the average velocity of the captured atoms will be "about 0 m/s" and they will be entirely converted into reaction mass expelled backward at (the speed of light minus the speed of the spaceship), a significant gain even when the craft is travelling at its maximum velocity.

Not really sure of the 4 year 1/4 path time either. It may have been 8 years?
not rated yet May 10, 2011
Wouldn't the hydrogen atoms be in currents of various solar winds? If that's the case, then they would most definately be in-motion...
not rated yet May 10, 2011
I really like the idea from stargate universe, though i'm sure it didn't originate there. The ship in that show could fly on in the outer atmosphere of a star to collect its energy... That would be ideal since we will always be traveling to areas with stars.

I really think our next BIG thing when the shuttle is killed should be a reusable interplanetary real space ship, something flexible that can't land but has plenty of landing modules. Something that could be flone all over the solar system with the right prep work, something that will allow us to toe back iron rich asteroids so that we can start to build more ships directly in space, building on earth or even transporting the materials from earth is a waste of energy in my eyes. We need to build a ship for purposes of exploring our solar system flexibly, and with the ability to bring raw large quantities of raw materials back.
not rated yet May 10, 2011
As soon as such a ship is built, one of us geeks out there, that just happens to have the last name of Kirk... Well, you know what you'll have to do...
not rated yet May 10, 2011
Do what we always seem to do with space exploration... use it for military research and only give lip service to science?
not rated yet May 10, 2011
Well, I was thinking have a son named James Tiberius... but it'd probably go more like you said...