Overview

High-energy Particle physics is one of the coolest branches of physics! Particles travelling close to the speed of light, collisions realising a plethora of new particles, and massive setups researching at very high energies. Not only do particle physics experiments give us insight into the mysteries that lie beyond our current understanding of the world, but they also contribute to many of the applications and inventions that make our lives better. You like tv? well, we definitely wouldn’t have those without particle physics.

This website serves as a resource for high-school physics teachers who are teaching grade 11/12 physics. We’ll focus on the basic concepts of particle accelerators and detectors, their importance and use in modern physics, as well as go through the constructions and presentation of two demonstrations, a ping-pong ball cyclotron, and a DIY cloud chamber.

Background

The presentation focuses on a base introduction to particle accelerators and the role they play in physics.

here's a possible outline with slide titles and talking points for your presentation:

Slide 1: Introduction

• Briefly introduce yourself and the topic

• Explain that the presentation will cover the physics of particle accelerators

• Highlight the importance of particle accelerators in scientific discovery and real-world applications

• Mention that you will be using a model cyclotron and a DIY dry ice cloud chamber to demonstrate some of the concepts

Slide 2: What is a particle accelerator?

• Explain what a particle accelerator is in simple terms

• Highlight the many ways in which particle accelerators can be used, from medical treatments to exploring the nature of the universe

• Mention that today we will focus on the use of particle accelerators in particle physics

Slide 3: How do particle accelerators work?

• Explain the basic principles of how particle accelerators work, using electric and magnetic fields to accelerate charged particles and guide them towards a target or collision point

• Highlight the importance of mass-energy equivalence in particle physics and how it relates to particle acceleration

Slide 4: The importance of particle physics

• Explain why particle physics is an important field of study

• Highlight some of the major discoveries made using particle accelerators, such as the discovery of the Higgs boson

• Discuss how these discoveries have advanced our understanding of the universe and opened up new possibilities for scientific discovery

Slide 5: Real-world applications of particle accelerators

• Discuss some of the real-world applications of particle accelerators, such as medical treatments and materials science

• Highlight the importance of radiation therapy in cancer treatment

• Discuss some of the ways in which particle accelerators can be used to create new materials with unique properties

Slide 6: Demo 1 - Model Cyclotron

• Demonstrate the model cyclotron and explain how it works

• Discuss the similarities and differences between the model cyclotron and a real cyclotron accelerator

• Encourage students to ask questions and make observations about the demo

Slide 7: Demo 2 - DIY Dry Ice Cloud Chamber

• Demonstrate the DIY dry ice cloud chamber and explain how it works

• Show the patterns created by the mildly radioactive source of americium

• Discuss the importance of studying these patterns and how they help us understand the behavior of subatomic particles

• Encourage students to ask questions and make observations about the demo

Slide 8: Food for thought questions

• Pose some thought-provoking questions for students to consider, such as:
  • What do you think the next big discovery in particle physics will be?
  • How can we use particle accelerators to solve real-world problems?
  • What impact will particle physics have on our lives in the future?

• Encourage students to discuss their thoughts and ideas with their peers

Slide 9: Conclusion

• Summarize the main points of the presentation

• Thank the students for their attention and engagement

• Encourage them to continue learning about physics and consider pursuing a career in science

• Remind them that the world of particle physics is always changing and evolving, and there are many exciting discoveries yet to be made

Demonstrations

Ball Cyclotron

Particle accelerators don’t need to be as a massive as the LHC, that’s where the ball cyclotron comes in. It demonstrates many of the principles behind industrial grade accelerators: charge repulsion, object acceleration, cyclic movement.

In industrial accelerators subatomic particles are accelerated to near light speed, in order to have enough energies to break apart. LINACS are acommin way of doing so. They’re fairly simple. A charged particle is placed in a tube under vaccum, and an alternanting electric field is applied down the length of the tube at a frequency that the particles are pushed along in a linear trajectory and accelerated by each incrementa charge osscilation. We can create the same effect by alternating the charge of the particle and keeping the surrounding at a steady charge. The ping ball swithces from pasitive to negative back and forth as it spins around. like charges repel , and opposites attract. As it rolls, it comes in contact with alternating strips of aluinum tape, it shares the same charge as the strip as its conductive and it pushed to the next strip of opposite charge.

Materials

• Aluminum Tape and Foil

• Glass Base

• Ping-pong ball

• Volatage multiplier

• 5V AC/DC adapter (typical phone charger)

Putting it together

Construction: Take the bowl and clean thoroughly. Using the Aluminum tape create the pattern on the inside of the bowl shown above.

Place two strips of aluminum foil making an x pattern, so that they intersect right down the middle, as shown below. Then, place more tape in the middle of the four quadrants, do not connect this to the center, leave about 4 centimeters of space from the other strips, leave about 2 centimeters at the ends to wind to the bottom of the bowl.

On the underside connect up all the wound down edges of tape in a square sound the whole bottom as shown. Round off the tape from the top as shown.

That is it for the initial construction of the bowl. We’ll need something lightweight, and charged to accelerate. Ping-pong balls work great. We make it conductive by spraying it with conductive zinc paint, 2 layers should be enough to get an even finish, use more if necessary but remember to keep it light.

To run it we need a high voltage power supply, a Wimshurst machine or Van de graff generator would work very well. We don’t need high current and anything in the 10,000 volt range would be ideal.

Alternatively, a voltage multiplier could be bought such as the one used in the current setup. This one has an input rating of upto 6V DC, and effectively outputs 14 kV with a 5V, 3A input. I ended up using a USB-C phone charger to provide the DC input, simply cut one end of the USB-C cable, find the 2 power-carrying wires (the green ones in my case) and solder them to the input wires of the voltage multiplier.

Another possibility is to build a Cockcroft-Walton generator, with instructions here.

Then connect the negatives to the underside, and positive to the strips that are exclusively on top. (polarity does not matter, as long as both poles don’t get into direct contact). Turn on the power supply and ensure that there are no arc overs. If arcing occurs, trim some tape off the problem areas.

With the supply off, throw the ping pong ball into the bowl so it runs around the bottom of the bowl. Turn on the supply. The ball should accelerate and maintain velocity around the bowl.

Cloud Chamber

A basic Setup with a Dry Ice and Alcohol mist cloud chamber.

Materials:

• 2 see-through containers

• Felt

• Dry Ice

• Isopropyl alcohol

• Mild Radiation Source

Construction:

Use a glue gun to attach felt to the bottom of one of the see through containers. Place this inverted, over a container of dry-ice pellets after soaking the felt in the chamber with isopropanol. Place the second container on top of the first after filling it with hot water. Ensure a tight fit.

Achieving proper ‘clouding’ depends on many of the factors, humidity and temperature of the room being one of them, but after a couple of resets and ensuring a high tempereature differential, as well as tight fit will result in a good cloud.