What happened to antimatter? - Rolf Landua

Me and Rolf Landua holding the antimatter container of DaVinci's Code

Do you remember the antimatter bomb in the DaVinci's Code movie?

In my journey at CERN, Rolf Landua gave a lecture about antimatter. Basically the topics in the lecture was this questions: What is it? Where is it create? How can be created? What is the mystery behind it? How can we study it? Can we use it as a energy font or a bomb? Is any antimatter in our daylife?

In particle physics, antimatter is material composed of antiparticles, which have the same mass as particles of ordinary matter but have opposite charge and quantum spin. Antiparticles bind with each other to form antimatter in the same way that normal particles bind to form normal matter. For example, a positron (the antiparticle of the electron, with symbol e+) and an antiproton (symbol p) can form an antihydrogen atom. Furthermore, mixing matter and antimatter can lead to the annihilation of both, in the same way that mixing antiparticles and particles does, thus giving rise to high-energy photons (gamma rays) or other particle–antiparticle pairs. The end result of antimatter meeting matter is a release of energy proportional to the mass as the mass-energy equivalence equation, E=mc² shows.

At this time, the apparent asymmetry of matter and antimatter in the visible universe is one of the greatest unsolved problems in physics.

Antimatter is created in the LHC, and the LHCb is the detector responsible to detect particles in the antiprotons' collisions. The antiprotons' production is achieved with the collisions between protons and nucleus of Iridium, Cupper, and others. The antiprotons are decelerated and keep trapped with a combination of electric and magnetic fields (so it doesn't touch matter). In this way, the resultant material is detected by the detector before the annihilation. That event is one of the biggest mysteries of the Big Bang, and scientist are trying to answer it: the domination of the matter over the antimatter.

FDG is a glucose molecule, with fluorine-18 attached

This antimatter cannot be used as energy or weapon because we need energy to create it. Imagine that we want to produce 0.5 g of antimatter. Well, we need 22 kton (22,000 ton) of TNT (almost the same value of the Hiroshima's bomb), to produce 0.5 g of matter and antimatter. The energy in this process is about 4.5 x 10¹³ J. The total energy that we need (because the efficiency is 10^-9 %) will be 4,5 x 10²² J. Even with CERN's discount made by French Electric Company [1 kwh = 3,6 x 10⁶ J= 0,1 €], the total cost will be 1 x 10⁸ € and it will be take a billion years to produce and supply this production to CERN.

But, antimatter is used in our body for PET scan detection. The glucose has a fluorine-18 attached that will emit positrons when that molecule travels in our body, and the scanner detects where the positrons go.

The next step that scientist at CERN are trying to develop is to use positrons and antiprotons as therapy in some deceases.

References:

• Antimatter - Wikipedia
• Having a Pet Scan
• Antimatter presentation - Rolf Landua, CERN

HST2012, CERN - Day 12

Rolf Landua and ME holding the antimatter bottle.

During this day we had two lectures and we continued into work group

The first lecture was the continuation about Accelerators. We leaved the technical details and we got into the Physics: energy, number of events, luminosity, etc.

It was emphasized that in the LHC does not circulate a steady stream of protons, they are sent in bunches and compressed by existing dipoles and quadrupoles in the accelerator. The curvature and focal power we use in optics is applied here at the LHC in terms of the strength of the different magnets. The magnetic field created at the LHC is 8.33 T, in the Earth is situated between 24 mT and 66 mT. There are approximately 6000 magnets in the LHC.

The second lecture was about Antimatter, performed by Rolf Landua based on the movie Angels and Demons. Basically, we tried to respond to seven questions related to the subject: What is it? Where is it created? How is it created? What is the mystery behind this? How to study it? Can be used as energy source or a bomb? There antimatter in our day-to-day?

Antimatter is real and is composed of antiparticles. For example, the hydrogen atom is formed by a proton and an electron, in the version of the antimatter, antihydrogen consists of a positron and antiproton. Antimatter is created in the LHC, the LHCb is the detector for those particles. 

To create antiprotons, LHC collide protons with cores of Iridium, copper, etc. .. Antiprotons are created, retarded and maintained as "prisoners" in a combination of electric and magnetic fields. Thus the material before the resulting annihilation is captured by the detector. 

This annihilation is one of the great mysteries of the Big Bang that scientists try to answer (the conversion of antimatter to matter in this dominance). 

This antimatter can not be used as energy or weapon because it requires a lot of energy to produce it. To have an idea, we use the following example: Let's try to create 0.5 g of antimatter. Therefore, it is necessary 22 kton (kilo ton) of TNT (approximately the same as Hiroshima's bomb) to produce a half gram of matter and antimatter. The energy associated with 0.5 g of antimatter is  4,5 x 10¹³ J. The total energy required (efficiency ~10^-9 %) would be  4,5 x 10²² J. Even with the CERN discount given by the French electricity company [1 kWh = 3.6 x 106 J = 0.1 €], the cost would be  1 x 10⁸ €  and would take one billion years deliver it.

Finally, it should be noted that antimatter is used in the body, where a proton is replaced by a positron in the glucose molecule to be detected by PET (Positron Emission Tomography) used in medicine. The next step for the scientists will be create a therapy using positrons.

 About the work we are developing in groups I will talk about later.

ScienceCasts: Alien Matter in the Solar System

Anti-Gravity

Image credit: NASA

Antimatter gravity could explain Universe's expansion

(PhysOrg.com) -- In 1998, scientists discovered that the Universe is expanding at an accelerating rate. Currently, the most widely accepted explanation for this observation is the presence of an unidentified dark energy, although several other possibilities have been proposed. One of these alternatives is that some kind of repulsive gravity – or antigravity – is pushing the Universe apart. As a new study shows, general relativity predicts that the gravitational interaction between matter and antimatter is mutually repulsive, and could potentially explain the observed expansion of the Universe without the need for dark energy.

Versão Portuguesa aqui.