In this video we go over the basics of what are particle accelerators, why they are built for, how physicist use them to probe and push the boundaries of quantum and particle physics, and how particle accelerators are able to generate tiny amounts of antimatter.
Particle accelerators are massive underground facilities that accelerate beams of particles curved by magnetic fields until they collide inside of a detector, which is able to study and collect data from the high energy colliions.
The largest and most powerful current particle accelerator is the Large Hadron Collider operated by CERN, outside of Geneva, Switzerland. Previously it used to be the Tevatron operated by Fermilab in Illinois, USA.
Mysterious fundamental particle (Lepton). Here is the transcript of the video if you’d prefer the content in text form:
There exists a particle so small that billions if not trillions are traveling through you right now. They are so small and have such a small charge that they go right through molecules and atoms. Forged in high-energy environments like the nuclear furnace in the core of our sun. Particles that can travel through hundreds of miles of matter as if it wasn’t there, and they are so small they make an electron look as big as the sun. These particles are called neutrinos.
Neutrinos are subatomic particles that have very little or no mass and virtually no electrical charge. They are the most abundant particles in the universe and are produced in vast numbers in high-energy particles such as those observed in cosmic rays and other radioactive processes. Neutrinos interact extremely weakly with matter, making them difficult to detect. Neutrinos are mind-bogglingly tiny. They are hundreds of thousands of times lighter than the next lightest particle, which is the electron. They’re also ubiquitous. Tens of trillions of neutrinos pass through your body every second, originating mostly from the sun. But because of their small size and lack of charge, they rarely interact with your tissues—or anything else.
Neutrinos can pass through matter because they interact extremely weakly with other particles. This means that they do not interact with the atoms and molecules that make up matter, and thus can pass through it almost unimpeded. This makes them ideal for studying the universe, as they can travel vast distances in a relatively short amount of time.
Neutrinos come in three types, or flavors: electron, muon, and tau. The different types of neutrinos differ in terms of their mass, with electron neutrinos having the least mass and tau neutrinos having the most. They also differ in terms of how they interact with matter. Electron neutrinos interact weakly with matter, while muon and tau neutrinos interact more strongly. Finally, each type of neutrino oscillates between the other two types as they travel through space, so that an electron neutrino may eventually become a muon or tau neutrino.
Neutrinos are formed when a neutron inside of an atom decays into a proton and an electron, sending the electron away from the atom. This electron is known as an electron neutrino and is released from the atom in the form of a neutrino particle. Neutrinos can also be produced during various types of nuclear reactions, such as those that occur in a nuclear reactor. Or the fusion that occurs in the sun and stars
In 1930 renowned physicist Wolfgang Pauli was puzzled over a seemingly impossible conundrum. Over multiple experiments, Pauli’s contemporaries had noticed an accounting error when observing beta decay, a process by which certain radioactive atoms break down. Rather than being emitted as electrons, a small fraction of the decaying atom’s energy had apparently vanished.
This observation broke the first law of thermodynamics, which states that energy cannot be created or destroyed. So Pauli proposed what he described as a “desperate remedy”: a new type of small, chargeless fundamental particle that was emitted alongside the electrons and accounted for the missing energy. The idea of the neutrino was born.
Neutrinos were first detected in 1956 by American physicist Clyde Cowan and Frederick Reines in the neutrino experiment at the Savannah River Site in South Carolina.
It is estimated that around 65 billion neutrinos pass through every square centimeter of the Earth’s surface every second. This means that billions of trillions of neutrinos pass through the Earth each second. The weak force has a very short range, the gravitational interaction is extremely weak due to the very small mass of the neutrino, and neutrinos do not participate in the strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected.
Supernovae are violent stellar explosions that occur when the core of a massive star collapses in on itself. During a supernova, huge amounts of energy are released in the form of gamma rays, X-rays, visible light, and high-energy particles, including neutrinos. Supernovae can be used to study the structure and evolution of galaxies, and can even be used to measure the expansion of the universe.
Neutrinos are formed in supernovae as a result of the high-energy reactions taking place inside the collapsing star. During the explosion, protons and neutrons are fused together to form heavier elements, releasing a tremendous amount of energy in the form of neutrinos. These neutrinos carry away a large portion of the energy released by the supernova, allowing it to cool and eventually fade away.
Neutrinos are everywhere in the universe, but they are difficult to detect because they have virtually no mass and interact weakly with other particles. Neutrinos are created in the sun, in Earth’s atmosphere by cosmic rays, and in nuclear reactions in stars and supernovae. They can also be created artificially in particle accelerators.
Neutrinos are detected by measuring the tiny amount of energy they deposit when they interact with matter. This is usually done using very large, specialized detectors filled with a medium such as water or liquid scintillator. These detectors are designed to detect the Cherenkov radiation or scintillation light produced when a neutrino interacts with the medium.
Cherenkov radiation and scintillation are two different types of light emission that occur when high-energy particles pass through a medium. Cherenkov radiation is the blue glow that is seen when a charged particle passes through a medium at a speed faster than the speed of light in that medium. Scintillation is the flash of light that is produced when an ionizing particle passes through a material such as a crystal or liquid scintillator.
Some examples of neutrino detectors on Earth include:
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