M8- Topic 5 deep inside the atom Flashcards
what are the types of particles (2)
Force particles (gauge bosons) Matter particles
what are the types of force particles (4)
gravitons
weakons
Photons
Gluons
what are the types of matter particles (2)
- Fundamental particles
- Composite particles or Hadrons
what are the types of fundamental particles (2)
- quarks
- leptons
what are the types of quarks are there (6) and what are there charges
up: 2/3
down: -1/3
Top:2/3
Bottom: -1/3
charm: 2/3
strange: -1/3
what are the types of leptons (4 (lowest to highest energy)
electrons
neutrinos
muons
Tau
what types of composite particles/ hadrons are there (2)
Baryons
Mesons
what types of Baryons are there(2)
protons (uud)
neutrons(dud)
what types of mesons are there (2)
(particles with a quark antiquark pair)
- Pion (uđ)
- Kaon (us̅)
What experimental evidence was there for positrons
1932 Carl Anderson discovered the positron in a cloud chamber, observed it’s circular motion in a magnetic field to be the exact opposite of a electron
what was the evidence for muons
1937, physicists used the collisions of cosmic rays on a cloud chamber that left a unique trail dubbed the muon
Who theorised pions and how did they describe how it acted
- Japanese physcist Hideki Yukawa
- the mediating particle for the strong force where the pion is ejected to apply a force on another particle (this was wrong it was actually gluons, but at a large scale it seem that way)
What was the evidence of pions
1946, use of photographic plates created by occhialini and powell allowed for a more sensitive detection of particles present in cosmic waves thus finding the pion as described in Yukawa’s prediction
who predicted the neutrino, why did he predict it and what did they say it would do
- wolfgang pauli
- 1931, to account for the apparent loss in energy and momentum
- predicting the energy was taken from another particle called the neutrino
what is the experimental evidence for the neutrino (2)
- 1956, detected in nuclear reactors
- where an antineutrino and protons reacted to create neutrons and a positron
What evidence was there for protons and neutrons not being fundamental (2)
- increase discovery of new subatomic particles, made it seem unlikely that they where fundamental
- hypothesising the existence of quarks which were discovered through the use of particle accelerators and analysing ionisation paths of these quarks
- created two groups
- baryons (3 quarks)
- mesons (2 quarks)
what is an accelerator
a machine used to increase particles to higher speeds (thus higher energy) to hit a target
what are colliders
an accelerator in which two beams travelling in opposite directions, are steered together to create a high energy collision
what are accelerators and colliders used for
to gain more evidence about the internal structure of the nucleus and the forces holding it together
How these new particles detected in accelerators and colliders
through analysis of the arc of ionisation paths and combining it with information with conservation laws (momentum, mass-energy and quantum number)
what are the types of accelerators
- linear accelerators (linacs)
- cyclotrons
- synchrotrons
what is the structure of a linear accelerator (linacs) (2)
- a series of cylinders that increase in size, and are separated by a disk with hole to allow a beam through
- an alternating electric field in between each cylinder to accelerate the particles
what is the structure of a cyclotron (2)
- charged particles are accelerated in a alternating electric field in between two separated hollow metal plates called dees
- Magnetic field steers the particles in a semicircular shape until it exits a dee where the electric field will alternate accelerating the charged particle until leaves the accelerator as a beam
what is the structure of a synchrotron (3)
- are circular accelerators where a beam travels ina evacuated pipe which is steered by electromagnetic plates
- the particles go around millions of times
- allows it to be used as both an accelerator and collider
what are the limiting factors of a synchotron (2)
- accelerate charged particles to emit radiation and loose energy in the form of photons
- the superconductors (magnets) have a upper limit preventing it from operating if gone over.
