M8- Topic 5 deep inside the atom

Question 1

what are the types of particles (2)

Answer 1

Force particles (gauge bosons)
Matter particles

Question 2

what are the types of force particles (4)

Answer 2

gravitons
weakons
Photons
Gluons

Question 3

what are the types of matter particles (2)

Answer 3

• Fundamental particles

- Composite particles or Hadrons

Question 4

what are the types of fundamental particles (2)

Answer 4

• quarks

- leptons

Question 5

what are the types of quarks are there (6) and what are there charges

Answer 5

up: 2/3
down: -1/3
Top:2/3
Bottom: -1/3
charm: 2/3
strange: -1/3

Question 6

what are the types of leptons (4 (lowest to highest energy)

Answer 6

electrons
neutrinos
muons
Tau

Question 7

what types of composite particles/ hadrons are there (2)

Answer 7

Baryons

Mesons

Question 8

what types of Baryons are there(2)

Answer 8

protons (uud)

neutrons(dud)

Question 9

what types of mesons are there (2)

Answer 9

(particles with a quark antiquark pair)

• Pion (uđ)
• Kaon (us̅)

Question 10

What experimental evidence was there for positrons

Answer 10

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

Question 11

what was the evidence for muons

Answer 11

1937, physicists used the collisions of cosmic rays on a cloud chamber that left a unique trail dubbed the muon

Question 12

Who theorised pions and how did they describe how it acted

Answer 12

• 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)

Question 13

What was the evidence of pions

Answer 13

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

Question 14

who predicted the neutrino, why did he predict it and what did they say it would do

Answer 14

• wolfgang pauli
• 1931, to account for the apparent loss in energy and momentum
• predicting the energy was taken from another particle called the neutrino

Question 15

what is the experimental evidence for the neutrino (2)

Answer 15

• 1956, detected in nuclear reactors

- where an antineutrino and protons reacted to create neutrons and a positron

Question 16

What evidence was there for protons and neutrons not being fundamental (2)

Answer 16

• 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
  
  1. baryons (3 quarks)
  2. mesons (2 quarks)

Question 17

what is an accelerator

Answer 17

a machine used to increase particles to higher speeds (thus higher energy) to hit a target

Question 18

what are colliders

Answer 18

an accelerator in which two beams travelling in opposite directions, are steered together to create a high energy collision

Question 19

what are accelerators and colliders used for

Answer 19

to gain more evidence about the internal structure of the nucleus and the forces holding it together

Question 20

How these new particles detected in accelerators and colliders

Answer 20

through analysis of the arc of ionisation paths and combining it with information with conservation laws (momentum, mass-energy and quantum number)

Question 21

what are the types of accelerators

Answer 21

• linear accelerators (linacs)
• cyclotrons
• synchrotrons

Question 22

what is the structure of a linear accelerator (linacs) (2)

Answer 22

• 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

Question 23

what is the structure of a cyclotron (2)

Answer 23

• 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

Question 24

what is the structure of a synchrotron (3)

Answer 24

• 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

Question 25

what are the limiting factors of a synchotron (2)

Answer 25

• 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.