Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
You can change this under Settings & Account at any time.
Transcript of Antimatter
anti-helium 4 nuclei. •Later, even higher energy accelerators at Serpukhov, Russia, and at CERN allowed scientists to produce and observe anti-helium 3 nuclei. •At the Proton Synchrotron at CERN, Antonino Zichichi and other colleagues announced that they had created the nuclei of anti-deuterium in 1965. How Positrons are Made •As mentioned before, collisions of particles with high amounts of energy produce antimatter. •Eventually a whole "shower" of electrons, positrons, and photons is made. At this point, positrons can be collected with magnets and placed in particle accelerators for more experiments. •The second nucleus is there to exchange energy and momentum with, otherwise you cannot start with a photon (zero mass) and end up with two objects with mass and conserve energy and momentum. • As electrons are deflected from their straight path, they release some energy in the form of high-energy photons. These photons can then travel near another nucleus and spontaneously become an electron-positron pair. •When high energy electrons are shot near the nuclei of atoms, the electrons will get deflected due to the electric field around the charged nuclei. If the charge of the nuclei is larger, the electrons will be deflected more frequently and at greater angles. •The electron-positron pairs created can then go scattering towards other nuclei, radiate photons which can then produce more electron-positron pairs. •In summary, electrons travelling fast enough towards a piece of material called a target (preferably made out of atoms that have a large atomic number), will have a shower of electrons, positrons and photons. How Antiprotons are Made •At CERN, the Proton Synchrotron accelerates protons to energies of 26 GeV which then collide into an iridium rod. •The composition of an antiproton is two up antiquarks and one down antiquark. •At Fermi National Accelerator Laboratory (Fermilab), antiprotons are produced in a similar way. •The antiprotons are collected using magnets in vacuum. • The protons bounce off the iridium nuclei with enough energy for matter to be created. A range of particles and antiparticles are formed. How is Antimatter Stored? •Antimatter is not something that can easily be stored in a container because it will annihilate with matter as soon as it touches. •This is how on April 26, 2011, CERN announced that they had trapped 309 anti-hydrogen atoms, for about 1,000 seconds. •It is more difficult to trap neutral antiparticles because most of them hit the walls of the trapping chamber where they annihilate with the ordinary atoms of normal matter. •Charged antimatter can be contained in a device called Penning Trap which uses electric and magnetic fields. •However the spins (angular momentum) of their subatomic particles produce a magnetic moment. This magnetic field can be influenced by an outside magnetic field which means that some anti-hydrogen atoms are attracted to it. By interacting with this magnetic field it is possible to trap anti-hydrogen atoms. •For example, anti-hydrogen is neutral and therefore is unaffected by the electric and magnetic fields used to trap the charged positrons and antiprotons. Cost of Production Uses in Medicine Antimatter as an Alternative Source of Fuel •With current technology it would cost over $ 100 000 000 000 to produce just 1 milligram of antimatter. •Also, storing antimatter is another problem because it doesn’t last very long. •It is created at such tremendous inefficiencies that making substantial quantities would drain the entire planet's power supply. •The reason for this is that the production of antiprotons is complicated since few are produced during reactions inside particle accelerators. The production rate of antimatter is very small. •Creating anti-matter is important in Positron Emission Tomography (PET) scans. •Small amounts of a radioactive substance are inserted into a person’s body. As this substance decays, positrons are produced. •A PET scan uses the gamma photons released from the annihilation of electrons and positrons. •PET scans are used for medical purposes. It is used to measure blood flow, detect cancer, and detect coronary artery disease. •When positrons annihilate with electrons in the body, gamma rays (high energy photons) are emitted. These gamma rays are detected to make a map of where this substance has spread inside the body. •As of today, antimatter is not an appropriate source of fuel because there is hardly any of it found on Earth. •Since the energy density of antimatter is higher than that of conventional fuels, an antimatter fueled spacecraft would have a higher thrust-to-weight ratio than a conventional spacecraft. Small amounts of antimatter could provide longer rocket propulsion. •If there was enough antimatter, it could be used as a fuel source to power rockets for interplanetary trips or even long interstellar voyages. •It would take about 100 000 000 000 years for the facilities at CERN to produce 1 gram or 1 mole of anti-hydrogen. •Antimatter could be used as a renewable and efficient source of fuel but the cost of producing it outweighs the benefits of the energy it could produce. Antimatter production would take a really long time to produce in today’s particle accelerators. In a magnetic field, charged particles follow curved paths, with opposite charges curving in opposite directions. Positron emitting radioisotopes are prepared by bombarding stable atomic nuclei with protons. Protons are speeded up in a particle accelerator which then collide with the stable nuclei, and knocks out one neutron from its nucleus. The proton now occupies the position where the ousted neutron once stayed. But this atomic configuration is unstable, so the proton now decays by emitting positron. Fluorine-18 is the most commonly used radioisotope. Antimatter Rockets for Long Space Mission According to NASA, antimatter could be the most potent fuel source known to man. Once idea is to create a rocket that is propelled by a positron reactor. This is why positrons are the best choice because their annihilation releases gamma rays with about 400 times less energy than antiproton annihilation. One danger of using antimatter is that when it annihilates with matter, it can release high energy gamma rays which are dangerous. These gamma rays can penetrate matter and even break up molecules. The NASA Institute for Advanced Concepts (NIAC) is funding a team of researchers who are currently working on a new design for an antimatter-powered spaceship. When antimatter meets matter, both annihilate in a complete conversion to energy and this is what makes antimatter so powerful. A trip to Mars would require tons of chemical fuel. But a couple of milligrams of antimatter could be enough. Antimatter Theories that need more Research One Electron Theory Any Questions? Gravitational Polarization of the Quantum Vacuum Tully-Fisher Experiment Gravitational dipole fluid • The theory derives the famous Tully-Fisher Experiment
The Tully-Fisher experiment is an empirical that is based on numerical data collected by numerous observations of galaxies and clusters Time Space During his nobel prize lecture, Feynman told a story about Wheeler calling him in the middle of the night
Wheeler told him he derived the solution to the indistinguishability of electrons
They are all the SAME electron