Lecture 1: Accelerators

Question 1

What are the main uses of high energy particles?

Answer 1

• Nuclear and particle physics research
• Synchrotron light sources
• Spallation neutron sources
• Medical imaging
• Cancer treatment (radiotherapy)
• Food sterilisation
• Ion implantation
• Lithography

Question 2

High energy particles occur naturally from _________ _____ but it is often useful to increase their energy using a ________ __________.

Answer 2

Radioactive decay
Particle accelerator

Question 3

How can a particles energy be increased?

Answer 3

By decreasing its de Broglie wavelength (λ = h/p).

Question 4

What is a Livingstone diagram?

Answer 4

A graph that charts the development of accelerators over time in terms of particle energy.

Question 5

What is the equation for the force on a charged particle subject to an E-field and B-field?

Answer 5

F = force
q = charge
E = electric field
B = magnetic field
v = velocity

Question 6

An electric field causes a change in a particle’s ______ whereas a magnetic field causes a change in _________ (_______ __________).

Answer 6

Energy
Direction
Radial acceleration

Question 7

What is the equation that relates a particles mass and velocity to the magnetic field that it is in?

Answer 7

q = charge
v = velocity
B = magnetic field
m = mass
R = bending radius

Question 8

What is the equation for the bending radius of a particle?

Answer 8

R = bending radius
m = mass
v = velocity
q = charge
B = magnetic field
p = momentum

Question 9

Define magnetic rigidity

Answer 9

The reluctance of a particle to be bent by a magnetic field, given by BR. This ignores relativistic particles.

Question 10

What is the equation for magnetic rigidity?

Answer 10

BR = magnetic rigidity
p = momentum
q = charge