Antimatter Propulsion

Antimatter Propulsion Could Revolutionize Space Travel

Antimatter propulsion rockets would be using the propellant thousands of times more powerful than nuclear fuel and billions of times more efficient than the best jet engine humans will ever be able to make. These engines would allow us to extend our reach across our galactic and travel at nearly speed-of-light velocities.


Competitive Thrust-to-Weight Ratios Make Antimatter Propulsion Attractive Perspective
Thrust-to-weight ratio shows how many pounds of thrust are generated for each pound of engine weight. Though thrust-to-weight ratios are comparable to the ones of regular rocket propulsion, there is a profound advantage in energy density, leaving all other types of fuel way behind.
The Power of Antimatter Propulsion

Antimatter is a mirror reflected image of regular matter in many ways, except that most of its properties are reversed. The nucleus is a negative proton (antiproton) with positrons rotating around it. Even gravity of antimatter does not have the same properties matter does, in fact they gravitate away from each other. If however, antimatter is forced towards matter, the electrical forces kick in and it becomes possible for the two opposites to collide. When antimatter and matter particles meet, they terminate each other releasing tremendous amount of energy: thousands of times more than nuclear fusion reaction is able to release! Not only that, but the efficiency of the annihilation is worth noting since almost 100 percent of the mass is converted into energy, while only few percent of nuclear reaction gets converted into energy. The energy density is phenomenal and thrust-to-weight ratios are comparable to those of chemical propulsion. Consider this: it would take one ounce of antimatter to send the Space Shuttle on the orbit about 3000 times.

Different Types of Antimatter Propulsion and Power Generation 

Antimatter annihilation can be used in a few different ways: Direct antimatter propulsion, heating up of a working fluid which is then used as a propellant, and as a electricity generator.

The Propulsion of Reaction Products

In the subject we are discussing, the energy is released when antiproton is annihilated producing two types of mesons plus gamma rays. The charged mesons can be used as a propellant, directed through the magnetic nozzle to produce thrust. However, this model lacks efficiency because the rest of the particles - the uncharged mesons and gamma rays - would go to waste in this case, since gamma rays are not much help in generating thrust due to their low mass, and uncharged particles are not subject to magnetic fields therefore can’t be successfully used as a propellant. Building a mirror to reflect and redirect gamma rays towards one direction could improve the efficiency of this model somewhat.

Heating up a Working Fluid Propellant

Since the thrust is determined by the velocity and the mass of a propellant combined there is a way to increase it by adding the working fluid as a supplement propellant. The fluid is designed to expand profoundly when heated up by the products of antimatter annihilation. The main idea remains unchanged, however: the products of reaction are used to generate the thrust.

Generating Energy Using Antimatter

The idea of generating an electric power using antimatter annihilator or nuclear reactor has been around for a while and is not that far from becoming feasible. The real problem, however, lays in our inability to convert that power into thrust today. Most publications call this mysterious propulsion "some form of electric space propulsion system". Only inertial propulsion qualifies to be called a form of electric propulsion, all other forms belong to reaction propulsion category -they produce thrust as a reaction of exhausting the propellant at high speed in the opposite direction. 

The Secrets of Exhaust Velocity

The exhaust velocity of charged particles largely depends on two factors: the initial particle speed at the point of “creation” and the efficiency of the magnetic nozzle design. In the past, scientists have calculated that charged particles could potentially travel at up to 90% the speed of light at 100% nozzle efficiency. Unfortunately, the magnetic nozzle would be only 35% efficient. Therefore, reaching about 30% the speed of light was the realistic expectation of most research teams at that time.

New Findings: Beamed Core Approach

Improved results have been delivered by the group of scientists using new comprehensive software Geant 4 released by the CERN recently. Previous versions of Geant software calculated exhaust speeds of up to 33% the speed of light, but recent simulations using new version have proved that reaching speeds of almost 70% is possible using Beamed Core technology. Beamed core model proposes to generate thrust using magnetic nozzle where electrically charged annihilation products would be deflected, lined up and accelerated in one direction producing thrust. Magnetic nozzle able to produce electromagnetic fields of these magnitudes is no more science fiction.

Fuel Source is the Earth's geomagnetic belt

It has been proven that the geomagnetic field of the Earth attracts and maintains the mix of charged subatomic particles. Theoretically, positrons and antiprotons are thepart of that mix located at altitudes of several hundred miles. One of the recent studies reports the discovery of an antiproton radiation belt around the Earth. PAMELA experiment has calculated the measurements of the proposed belt and even the amount of energy it contains. The experiment confirms previous studies constituting that the Earth's geomagnetic belt is the closest abundant source of antiprotons.

References: NASA, Ronan Keane, Wei-Ming Zhang, General Physics, Popular Physics, British Interplanetary Society