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Antimatter ANTIMATTER INTRODUCTION Antimatter rockets are what the majority of people think about when talking of rockets for the future. This is hardly surprising as it is such an attractive word for the writers of science fiction. It is, however, not only interesting in the realm of science fiction. Make no mistake; antimatter is real. Small amounts, in the order of nanograms, are produced at special facilities every year. It is also the most expensive substance of Earth; in 1999 the estimated cost for 1 gram of antimatter was about $62.5 trillion. The reason it is so attractive for propulsion is the energy density that it possesses. Consider that the ideal energy density for chemical reactions is 1 x 10 7 (10^7) J/kg, for nuclear fission it is 8 x 10 13 (10^13) J/kg and for nuclear fusion it is 3 x 10 14 (10^14) J/kg, but for the matter-antimatter annihilation it is 9 x 10 16 (10^16) J/kg. This is 10 10 (10 billion) times that of conventional chemical propellants. 1

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Page 1: Antimatter Seminar Report

Antimatter

ANTIMATTER INTRODUCTION

Antimatter rockets are what the majority of people think about when

talking of rockets for the future. This is hardly surprising as it is such an

attractive word for the writers of science fiction.

It is, however, not only interesting in the realm of science fiction.

Make no mistake; antimatter is real. Small amounts, in the order of nanograms,

are produced at special facilities every year. It is also the most expensive

substance of Earth; in 1999 the estimated cost for 1 gram of antimatter was

about $62.5 trillion.

The reason it is so attractive for propulsion is the energy density that

it possesses. Consider that the ideal energy density for chemical reactions is 1

x 107 (10^7) J/kg, for nuclear fission it is 8 x 1013 (10^13) J/kg and for nuclear

fusion it is 3 x 1014 (10^14) J/kg, but for the matter-antimatter annihilation it is

9 x 1016 (10^16) J/kg. This is 1010 (10 billion) times that of conventional

chemical propellants.

This represents the highest energy release per unit mass of any known

reaction in physics. The reason for this is that the annihilation is the complete

conversion of matter into energy governed by Einstein's famous equation

E=mc2, rather than just the part conversion that occurs in fission and fusion.

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WHAT IS ANTIMATTER?

Antimatter is exactly what you might think it is -- the opposite of

normal matter, of which the majority of our universe is made. Until just

recently, the presence of antimatter in our universe was considered to be only

theoretical. In 1928, British physicist Paul A.M. Dirac revised Einstein's

famous equation E=mc2. Dirac said that Einstein didn't consider that the "m"

in the equation -- mass -- could have negative properties as well as positive.

Dirac's equation (E = + or - mc2) allowed for the existence of anti-particles in

our universe. Scientists have since proven that several anti-particles exist.

These anti-particles are, literally, mirror images of normal matter.

Each anti-particle has the same mass as its corresponding particle, but the

electrical charges are reversed. Here are some antimatter discoveries of the

20th century:

Positrons - Electrons with a positive instead of negative charge.

Discovered by Carl Anderson in 1932, positrons were the first evidence

that antimatter existed.

Anti-protons - Protons that have a negative instead of the usual positive

charge. In 1955, researchers at the Berkeley Bevatron produced an

antiproton.

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Anti-atoms - Pairing together positrons and antiprotons, scientists at

CERN, the European Organization for Nuclear Research, created the

first anti-atom. Nine anti-hydrogen atoms were created, each lasting

only 40 nanoseconds. As of 1998, CERN researchers were pushing the

production of anti-hydrogen atoms to 2,000 per hour.

Particle Annihilation

When antimatter comes into contact with normal matter, these equal

but opposite particles collide to produce an explosion emitting pure radiation,

which travels out of the point of the explosion at the speed of light. Both

particles that created the explosion are completely annihilated, leaving behind

other subatomic particles. The explosion that occurs when antimatter and

matter interact transfers the entire mass of both objects into energy. Scientists

believe that this energy is more powerful than any that can be generated by

other propulsion methods.

The problem with developing antimatter propulsion is that there is a

lack of antimatter existing in the universe. If there were equal amounts of

matter and antimatter, we would likely see these reactions around us. Since

antimatter doesn't exist around us, we don't see the light that would result from

it colliding with matter.

It is possible that particles outnumbered anti-particles at the time of

the Big Bang. As stated above, the collision of particles and anti-particles

destroys both. And because there may have been more particles in the universe

to start with, those are all that's left. There may be no naturally-existing anti-

particles in our universe today. However, scientists discovered a possible

deposit of antimatter near the center of the galaxy in 1977. If that does exist, it

would mean that antimatter exists naturally, and the need to make our own

antimatter would be eliminated.

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PRODUCTION OF ANTIMATTER

There is technology available to create antimatter through the use of

high-energy particle colliders, also called "atom smashers." Atom smashers,

like CERN, are large tunnels lined with powerful super magnets that circle

around to propel atoms at near-light speeds. When an atom is sent through this

accelerator, it slams into a target, creating particles. Some of these particles are

antiparticles that are separated out by the magnetic field. These high-energy

particle accelerators only produce one or two picograms of antiprotons each

year. A picogram is a trillionth of a gram. All of the antiprotons produced at

CERN in one year would be enough to light a 100-watt electric light bulb for

three seconds.

Atom smasher

Antiproton Decelerator (AD)

The Antiproton Decelerator is a very special machine compared to

what already exists at CERN and other laboratories around the world. So far,

an "antiparticle factory" consisted of a chain of several accelerators, each one

performing one of the steps needed to produce antiparticles. The CERN

antiproton complex is a very good example of this.

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At the end of the 70's CERN built an antiproton source called the

Antiproton Accumulator (AA). Its task was to produce and accumulate high-

energy antiprotons to feed into the SPS in order to transform it into a "proton-

antiproton collider". As soon as antiprotons became available, physicists

realized how much could be learned by using them at low energy, so CERN

decided to build a new machine: LEAR, the Low Energy Antiproton Ring.

Antiprotons accumulated in the AA were extracted, decelerated in the PS and

then injected into LEAR for further deceleration. In 1986 a second ring, the

Antiproton Collector (AC), was built around the existing AA in order to

improve the antiproton production rate by a factor of 10.

The AC is now being transformed into the AD, which will perform all

the tasks that the AC, AA, PS and LEAR used to do with antiprotons, i.e.

produce, collect, cool, decelerate and eventually extract them to the

experiments.

What does the AD consist of?

The AD ring is an approximate circle with a circumference of 188 m.

It consists of a vacuum pipe surrounded by a long sequence of vacuum pumps,

magnets, radio-frequency cavities, high voltage instruments and electronic

circuits. Each of these pieces has its specific function:

- Antiprotons circulate inside the vacuum pipe in order to avoid contact with

normal matter (like air molecules), and annihilate. The vacuum must be

optimal, therefore several vacuum pumps, which extract air, are placed

around the pipe.

- Magnets as well are placed all around. There are two types of magnets: the

dipoles (which have a North and a South pole, like the well-known

horseshoe magnet) serve to change the direction of movement and make

sure the particles stay within their circular track. They are also called

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"bending magnets". Quadrupoles (which have four poles) are used as

'lenses'. These "focusing magnets" make sure that the size of the beam is

smaller than the size of the vacuum pipe.

- Magnetic fields can change the direction and size of the beam, but not its

energy. To do this you need an electric field: this is provided by radio-

frequency cavities that produce high voltages in synchronicity with the

rotation of particles around the ring.

- Several other instruments are needed to perform more specific tasks: two

cooling systems "squeeze" the beam in size and energy; one injection and

one ejection system let the beam in and out of the machine.

How does the AD work ?

Antiparticles have to be created from energy (remember: E = mc2).

This energy is obtained with protons that have been previously accelerated in

the PS. These protons are smashed into a block of metal, called a target. We

use Copper or Iridium targets mainly because they are easy to cool. Then, the

abrupt stopping of such energetic particles releases a huge amount of energy

into a small volume, heating it up to such temperatures that matter-antimatter

particles are spontaneously created. In about one collision out of a million, an

antiproton-proton pair is formed. But given the fact that about 10 trillion

protons hit the target (about once per minute), this still makes a good 10

million antiprotons heading towards the AD.

The newly created antiprotons behave like a bunch of wild kids; they

are produced almost at the speed of light, but not all of them have exactly the

same energy (this is called "energy spread"). Moreover, they run randomly in

all directions, also trying to break out 'sideways' ("transverse oscillations").

Bending and focusing magnets make sure they stay on the right track, in the

middle of the vacuum pipe, while they begin to race around in the ring.

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At each turn, the strong electric fields inside the radio-frequency

cavities begin to decelerate the antiprotons. Unfortunately, this deceleration

increases the size of their transverse oscillations: if nothing is done to cure

that, all antiprotons are lost when they eventually collide with the vacuum

pipe. To avoid that, two methods have been invented: 'stochastic' and 'electron

cooling'. Stochastic (or 'random') cooling works best at high speeds (around

the speed of light, c), and electron cooling works better at low speed (still fast,

but only 10-30 % of c). Their goal is to decrease energy spread and transverse

oscillations of the antiproton beam.

Finally, when the antiparticles speed is down to about 10% of the

speed of light, the antiprotons squeezed group (called a "bunch") is ready to be

ejected. One "deceleration cycle" is over: it has lasted about one minute.

A strong 'kicker' magnet is fired in less than a millionth of a second,

and at the next turn, all antiprotons are following a new path, which leads them

into the beam pipes of the extraction line. There, additional dipole and

quadrupole magnets steer the beam into one of the three experiments.

The AD experiments

Three experiments are installed in the Antiproton Decelerator's

experimental hall:

ASACUSA:Atomic Spectroscopy and Collisions using Slow Antiprotons

ATHENA:Antihydrogen Production and Precision Experiments and

ATRAP:Cold Antihydrogen for Precise Laser Spectroscopy.

ATHENA and ATRAP's goal is to produce antihydrogen in traps, by

combining antiprotons delivered by the AD with positrons emitted by a

radioactive source.

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Antihydrogen atoms were first observed at CERN in 1995, and later

(1997) at Fermilab. In both cases they were produced in flight, that means they

moved at nearly the speed of light, i.e. much too fast to allow precise

measurements on any of their proprieties! They made unique electrical signals

in detectors that destroyed them almost immediately after they formed. Now

the idea is to produce slow antihydrogen atoms and store them into "traps",

allowing extremely accurate comparisons of the properties of hydrogen and

antihydrogen.

ASACUSA, on the other hand, will synthesize "exotic" atoms, in

which an electron is replaced by an antiproton. Precise laser spectroscopy of

these exotic atoms is expected to reveal lots of information on the behavior of

atomic systems.

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STORAGE

Antiparticles have either a positive or a negative electrical charge, so

they can be stored in what we call a trap which has the appropriate

configuration of electrical and magnetic fields to keep them confined in a

small place. Of course, this has to be done in good vacuum to avoid collisions

with matter particles. Antiatoms are electrically neutral, but they have

magnetic proprieties that can be used to keep them in "magnetic bottles".

Portable trap

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APPLICATION OF ANTIMATTER

PET Scan

Particle physicists regularly use collisions between electrons and their

antiparticles, positrons, to investigate matter and fundamental forces at high

energies. When electron and positron meet, they annihilate, turning into energy

which, at high energies, can rematerialize as new particles and antiparticles.

This is what happens at machines such as the Large Electron Positron (LEP)

collider at CERN.

At low energies, however, the electron-positron annihilations can be

put to different uses, for example to reveal the workings of the brain in the

technique called Positron Emission Tomography (PET). In PET, the

positrons come from the decay of radioactive nuclei incorporated in a special

fluid injected into the patient. The positrons then annihilate with electrons in

nearby atoms. As the electron and positron are almost at rest when they

annihilate, there is not enough annihilation energy to make even the lightest

particle and antiparticle (the electron and the positron), so the energy emerges

as two gamma rays, which shoot off in opposite directions to conserve

momentum.

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FUTURE OF ANTIMATTER

Antimatter as a propulsion system

This is not some incredible new technology that will power us

throughout the galaxy. At the most basic level the antimatter rocket is still a

Newtonian rocket, governed by the three laws of motion and it still conforms

to Einstein's theory of special relativity, in other words it cannot exceed the

speed of light.

Still if we are enable to develop such a propulsion system in the

future it will surely render any other Newtonian rocket obsolete overnight, the

system has the highest predicted efficiency, specific impulse and probably the

highest thrust to weight ratio. There does seem to be a serious amount of

disagreement over this last point, the general feeling seems to be that the thrust

to weight will at least comparable to today's very powerful chemical rockets.

What this means is that only 100 milligrams (1/10 gram) of antimatter would

be needed to match the total propulsive energy of the Space Shuttle (all those

huge tanks of fuel!).This fact has led to the interesting observation that future

advanced spacecraft, such as the antimatter rocket, will not be designed around

their propellant tank like conventional craft. Instead the craft will be designed

around the reactors (for nuclear craft) or around the systems and chambers to

cause annihilation (for antimatter craft). Radiation shielding will also become

a key component of spacecraft design.

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Antimatter propulsion systems

Once we have produced and stored the antimatter we can use it in

propulsion by releasing it into a chamber and allowing it to annihilate with

normal matter which produces its tremendous energy in the form of energetic

sub-atomic particles. There are actually two choices for propulsion. Well

electron-positron annihilation produces high energy gamma rays which are

impossible to control, hence useless for propulsion, and on top of this are

potentially very dangerous. Whereas the proton-antiproton annihilation

produces charged particles (mostly pions moving at velocities close to that of

light) that can be directed with magnetic fields, maximizing propellant mass.

The fact that there is this mass left over after the annihilation means that the

full conversion of mass to energy has not occurred as it does in the electron-

positron annihilation, therefore slightly less energy has been produced.

This energy, however, still far exceeds any other method and the

resulting particles allow this energy to be harnessed by directing it with

magnetic forces. In other words the perfect reaction does not produce perfect

propulsive result. Another important advantage for antimatter rockets over

nuclear rockets is that heavy reactors are not required, the reaction is

spontaneous. There are four main designs for an antimatter rocket, they are

listed here in increasing specific impulse:

Solid Core - Annihilation occurs inside a solid-core heat exchanger, the

reaction superheats hydrogen propellant that is expelled through a nozzle.

High efficiency and high thrust, but due to the materials the specific

impulse is only 1000secs at best.

Gas Core - Annihilation occurs in the hydrogen propellant. The charged

pions are controlled in magnetic fields and superheat the hydrogen; there

is some loss in the form of gamma rays that cannot be controlled. specific

impulse of 2500secs.

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Plasma Core - Annihilation of larger

amounts of antimatter in hydrogen

to produce a hot plasma. Plasma

contained in magnetic fields, again

some loss in form of gamma

radiation, the plasma is expelled to

produce thrust. There are no

material constraints here so higher specific impulse is possible

(anywhere from 5,000 to 100,000secs).

Beam Core - Direct one to one annihilation, magnetic fields focus the

energetic charged pions that are used directly as the exhausted

propellant mass. These pions travel close to speed of light so the

specific impulse could be greater than 10,000,000secs.

The spacecraft will have to be designed to be very long as the

annihilation products travel close to the speed of light.

Journey time

Estimates for travel times to Mars for an advanced antimatter rocket

using the beam core approach are anywhere from 24 hours to 2 weeks, it is

probable that it will be somewhere in between. Compare this to the space

shuttle using its conventional chemical propulsion when a trip to Mars would

take between 1 and 2 years.

Antimatter Spacecraft

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ANTIMATTER DETONATION

Over 99.9% of the mass of neutral antimatter is accounted for by

antiprotons and antineutrons. Their annihilation with protons and neutrons is a

complicated process. A proton-antiproton pair can annihilate into a number of

charged and neutral relativistic pions. Neutral pions, in turn, decay almost

immediately into gamma rays; charged pions travel a few tens of meters and

then decay further into muons and neutrinos. Finally, the muons decay into

electrons and more neutrinos. Most of the energy (about 60%) is thus carried

away by neutrinos, which have almost no interaction with matter and thus

escape into outer space.

The overall structure of energy output from an antimatter bomb is

highly dependent on the amount of regular matter in the area surrounding the

bomb. If the bomb is shielded by sufficient amounts of matter, the gamma rays

are absorbed and the pions slow down before decaying. Part of the kinetic

energy is thus transferred to the surrounding atoms, which heat up. In the event

of an antimatter detonation in the open atmosphere, most of the energy will

ultimately be carried away by the neutrinos, and the remainder by 10-100 MeV

gamma rays. The neutrinos would pass through the earth without being

attenuated, while gamma rays are relatively weakly absorbed by matter: they

lose roughly half of their energy per 500-1000 m of air, compared to only

20 cm of concrete. The explosion would not cause much physical damage

because its energy would be evenly dispersed over large area, although the

gamma rays may harm people standing nearby. Thus even if the impossible

problem of producing enough antimatter were solved, the antimatter bomb

would not be as practical or destructive as a conventional nuclear weapon.

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ANTIMATTER IN NATURE

About 15 billion years ago, matter and antimatter were created in a

gigantic Big Bang in equal amounts, at least according to today's best theory. It

is therefore surprising that our Earth, the solar system, and our galaxy (the

Milky Way) do not contain any antimatter.

To explain this absence, scientists have come out with two

possibilities: either antimatter completely disappeared during the history of

universe, or matter and antimatter have been separated from each other to form

different regions of the universe.

In the second case, we would be located in a region where only

matter exists (or rather what we call 'matter'), but some antimatter coming

from an 'anti' region outside our galaxy could still have a chance to reach us.

This antimatter would be in the form of anti-nuclei (like anti-Helium, anti-

Carbon, etc..) as opposed to lighter antiparticles (such as antiprotons) which

are also created in high energy collisions between ordinary matter. To search

for this extragalactic antimatter, the best way is to place a particle detector in

space.

AMS

A worldwide collaboration of physicists, lead by Nobel prize laureate

Prof. Samuel Ting of MIT, decided to build the 'Alpha Magnetic

Spectrometer', or AMS. AMS is a high-energy particle detector, which will

try to detect the passage of such very small amounts of antimatter, while

orbiting at an altitude of a few hundred kilometers above the atmosphere.

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Some of the main challenges of the project are very technical: having

to be carried on the Space Shuttle, each component of the apparatus has to be

miniaturized as much as possible to keep the total volume to a maximum of 10

cubic meters and the weight to a maximum of 3 tons (a typical high energy

apparatus at LEP with the similar detecting principles is about 1000 cubic

meters in volume and 100 tons in weight). Even more important is the power

consumption: AMS should not need more than 2 kW (kilowatts) of electricity,

provided by the solar panels of the Space Station. And 2kW is less than what a

kitchen oven needs!

AMS-01

A first simpler version of the experiment, AMS-01, traveled on the

Space Shuttle Discovery for a ten-day mission in 1998. The apparatus

consisted of a 6-layer 'silicon microstrip track detector' surrounded by a

permanent magnet and a few other systems.

Silicon microstrips can localize the passage of charged particles with

a precision of a few hundredth of a millimeter (less than a human hair). The

magnet produced a magnetic field where incoming particles were deflected in

opposite directions. Nuclei are thus identified by measuring both their mass

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and charge. During the 10 days that AMS was in space, not a single

antinucleus was seen among the 3 million nuclei that traversed the experiment.

In 2004, a new version of the experiment, called AMS-02, will be installed on

the International Space Station. AMS-02 will again be searching for any

extragalactic antimatter, but this time with more sensitivity, over a longer time

period and in a wider energy range.

The new apparatus will be equipped with a superconducting magnet,

providing a much higher magnetic field, and an enhanced silicon tracker, able

to record billions of tracks of matter (and antimatter?) particles. Other

detectors have also been added to the design to better identify and measure

incoming particles and nuclei. AMS-02 will be installed on the long arm of the

ISS and exposed to cosmic rays for three years.

This very moment, a few modules of ISS are already orbiting over

our heads. With the experimental data collected during this second mission,

AMS hopes to find the last traces of big-bang antimatter, if there are any left!

AMS-02

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PROBLEMS

Problems in Production

We would need at least several milligrams of antimatter to fuel a

beam core antimatter engine in local operations and several kilograms for

interstellar travel to Alpha Centuri. Given that currently 1-10 nanograms of

antiprotons are produced a year at Fermilab (Chicago) and CERN (Geneva), a

beamed core engine is not feasible in the near future.

Problems in Storage

The Penning trap has been developed, it is a portable antiproton trap

which is capable of storing 1010 (10^10) antiprotons for one week using the

superposition of electric and magnetic fields. The next stage is an

improvement to 1012 (10^12) antiproton storage. For complete antimatter

propulsion it is thought that 1020 (10^20) anti-protons will need to be stored.

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FAQ’S ABOUT ANTIMATTER

• What can antimatter be used for?

There are several different uses for antimatter, the main one being for

medical diagnostics where positrons are used to help identify different diseases

with the Positron Emission Tomography (or PET scan). For other uses, we are

still in the first phases of development and it's difficult to foresee what will

happen in the next ten years.

• Can we use antimatter to propel a car or a spaceship?

In principle, yes, but in practice it is very difficult. You all know that

the Star Trek Spaceship Enterprise flies around powered by antimatter. But in

reality, making antimatter is so difficult that it is hard to foresee it ever being

used as a propellant fuel. In order to propel a matter spacecraft weighing

several tons up to the speed of light, you would need an equal amount of

antimatter and, using the present technology, it would take millions and

millions of years to produce a sufficient amount. However, if you had a gram

of antimatter, you could drive your car for about 100.000 years.

• What does antimatter look like?

Matter and antimatter are identical. Looking at an object means

seeing the photons coming from that object; however, photons come from both

matter and antimatter. If there were a distant galaxy made out of antimatter,

you couldn't distinguish it from a matter galaxy just by seeing the light from it.

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• How can you be so sure there is not antimatter around?

If there was antimatter here, around us, it would annihilate with

matter and we would see light coming out. But we don't...About the possibility

of antimatter in space (antistars or antigalaxies), theorist have reasons to

believe that the Universe is all made of matter. But we are not 100% sure, and

that's way there are experiments, like AMS, which are going to look for it.

• If the only difference between a particle and its antiparticle is the

charge, how do you distinguish a neutron from an antineutron ?

Neutrons are made of quarks, and antineutrons are made of

antiquarks. Quarks and antiquarks have opposite charges, even though they

sum up to zero in both cases. And a very good way to recognize them is to put

a neutron close to an antineutron and see how they immediately annihilate.

• What about antiphotons?

Photons have zero charge and do not contain inside objects that are

charged, so a photon can not be distinguished from an antiphoton. Photon and

antiphotons are the same thing, i.e. the photon is its own antiparticle.

• How do sound waves propagate in antimatter?

If there is a difference between matter and antimatter, it is very very

tiny, that's why we are doing experiments here at CERN to investigate it. They

are so similar that sound waves, that are vibrations of matter or antimatter,

would be identical. An antimatter piano would sound exactly as a matter one.

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• How does the gravitational field act on antimatter?

 The gravitational force depends from the energy of an object, and

since matter and antimatter have both positive energy, gravitation acts on them

in the same way. This means that an object made of matter and one made of

antimatter would both stand on the floor, the latter one not flying off the sky.

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CONCLUSION

Due to the highest energy release per unit mass of any known

reaction ,we can say that antimatter will be a future energy source but first

need a reliable method of producing large amount of it.

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GLOSSARY

Cooling: By analogy with the kinetic theory of gases where heat is equivalent

to disorder, the term “cooling” designates the reduction of beam’s transverse

dimensions and energy spread. Different techniques can be used to this effect.

Electron cooling, more effective at low energy, uses an electron beam merged

with the antiproton beam, and acts as a heat exchanger between the two beams.

In the case of stochastic cooling, an error signal generated in a monitor is fed

back, via a collector, to the beam sample which created it, eventually centering

the sample’s characteristics towards the average value, after a large number of

passages through the apparatus.

Muon: an elementary particle having a mass 209 times that of the electron, a

negative electric charge, and mean lifetime of 2.210-6 seconds.

Neutrino: An electrically neutral particle that is often emitted in the process of

radioactive decay of nuclei. Neutrinos are difficult to detect, and their

existence was postulated twenty years before the first one was actually

discovered in the laboratory. Millions of neutrinos produces by nuclear

reactions in the sun pass through your body every second without disturbing

any atom.

Pion: it is produced either in a neutral form with a mass 264 times that of an

electron and a mean lifetime of 8.410-7 seconds or in a positively or

negatively charged form with a mass 273 times that of an electron and a mean

life time of 2.610-8 seconds.

Quarks: Subatomic particles which possess a fractional electric charge, and of

which protons, neutrons etc. are believed to be composed.

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Radio-Frequency or RF: The alternating voltage that provide (or takes)

energy to (or from) the beam to accelerate (or decelerate) it.

Specific impulse: It is an important parameter in spacecraft propulsion. It is

the thrust produced per unit weight flow rate of the propellant. The unit is in

seconds.

Synchrotron: Modern circular accelerator, where the particles are guided by

dipole magnets, focused by quadrupole magnets, and accelerated by RF

electric fields.

eV: The electron-Volt (eV) is the energy unit which corresponds to the

acceleration of a particle having the charge of the electron through a voltage

difference of one volt.

LEAR: CERN’s Low Energy Antiproton Ring, where the first nine atoms of

anti- hydrogen were observed.

PS: CERN’s Proton Synchrotron, which accelerated protons to its nominal

energy of 25 GeV for the first time in 1959, it has been upgraded to also

accelerate heavy ions, leptons (electrons and positrons), and antiprotons. Its

now at the heart of CERN’s accelerator complex.

LEP: CERN’s 100 GeV Large Electron-Positron collider, started in 1989, and

due to stop at the end of 2000. Its collision energy has now been upgraded to

202 GeV.

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REFERENCE

Fundamentals of Compressible Flow with Aircraft & Rocket

propulsion by S. M. Yahiya

http://livefromcern.web.cern.ch

http://public.web.cern.ch

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ABSTRACT

Antimatter is exactly what you might think it is -- the opposite of

normal matter, of which the majority of our universe is made. Until just

recently, the presence of antimatter in our universe was considered to be only

theoretical. In 1928, British physicist Paul A.M. Dirac revised Einstein's

famous equation E=mc2. Dirac said that Einstein didn't consider that the "m"

in the equation -- mass -- could have negative properties as well as positive.

Dirac's equation (E = + or - mc2) allowed for the existence of anti-particles in

our universe. Scientists have since proven that several anti-particles exist.

When antimatter comes into contact with normal matter, these equal

but opposite particles collide to produce an explosion emitting pure radiation,

which travels out of the point of the explosion at the speed of light. Both

particles that created the explosion are completely annihilated, leaving behind

other subatomic particles. The explosion that occurs when antimatter and

matter interact transfers the entire mass of both objects into energy. Scientists

believe that this energy is more powerful than any that can be generated by

other propulsion methods.

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CONTENTS

ANTIMATTER INTRODUCTION 1

WHAT IS ANTIMATTER? 2

PRODUCTION OF ANTIMATTER 4

STORAGE 9

APPLICATION OF ANTIMATTER 10

FUTURE OF ANTIMATTER 11

ANTIMATTER DETONATION 14

ANTIMATTER IN NATURE 15

PROBLEMS 18

FAQ’S ABOUT ANTIMATTER 19

CONCLUSION 22

GLOSSARY 23

REFERENCE 25

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