7.6 Linear Accelerators

Question 1

What is another name for a linear accelerator?

Answer 1

A linac

Question 2

What is a linear particle accelerator? - the structure

Answer 2

A long straight tube containing tube shaped electrodes

Question 3

What is a linear particle accelerator? - structure

Answer 3

A long straight tube containing tube shaped electrodes

Question 4

What is the charge of the tubes? Necessary for the function

Answer 4

Each consecutive tube has a different charge to previous

Question 5

How is the charge of the tube electrodes changed?

Answer 5

Using an alternating pd

Question 6

Why does the length of consecutive electrodes increase?

Answer 6

This is done to compensate for the increased speed of the charge particle so that the time spend in the electrodes is equal. This is done to make sure the synchronisation of alternating pd is correct

Question 7

Why does the pd alternate in this accelerator?and why is it timed

Answer 7

So that when a charged particle goes through the plate/electrode/tube the change of the charge of both tubes means the charged particle can be attracted to the next one and repelled from the previous one, making it accelerate. This is timed as time spent in each tube is equa.

Question 8

What is special about the velocity of charged particles in each tube?

Answer 8

It remains constant and the particle just drifts

Question 9

Where does the particle accelerate

Answer 9

In between the plates/electrodes so that the electric field accelerates it

Question 10

How would we calculate how long it takes to get through a linac when we have the amount of tubes and operating voltage frequency

Answer 10

F = 1/T

1/2 x 1/F to get time of 1 tube

Multiply time by amount of tubes

Question 11

Why do we half frequency on the last question ?

Answer 11

Since the particle will go through 2 tubes per 1 change of pd direction