Cockcroft 120 Challenge

Background:-

The Cockcroft Institute, based in Daresbury, Warrington, is a UK centre of excellence for particle accelerator physics research. The University of Liverpool Accelerator Science Cluster, a key academic research group within the institute, presents the Cockcroft 120 Challenge...

2017 marks the 120th anniversary of the birth of Sir John Cockcroft, the Nobel prize winner after whom the Cockcroft Institute is named.

Cockcroft, alongside Ernest Walton, was awarded the 1951 Nobel prize for the splitting of atoms, a feat made possible by the development of the Cockcroft-Walton voltage multiplier. The voltage multiplier allowed Cockcroft and Walton to generate the 100’s of thousands of volts needed to accelerate the charged particles used in their experiments.

To celebrate Cockcroft’s birth, we are asking you to conduct your own high voltage experiment and then to communicate your results. Electrostatic generators, such as Van de Graaff machines, can generate 100 kV+ at very low current, meaning that high voltage experiments can safely be carried out in the classroom. Remember, it requires around 30 kV for every cm of a spark’s length!

To discover more about our research, please visit our websites: www.liverpool.ac.uk/physics/research/accelerator-physics/ www.cockcroft.ac.uk

A Cockcroft Walton voltage multiplier. Located at the Cockcroft Institute, Daresbury Laboratory.

The Competition:- We invite you to create a video of up to 30 seconds in length that demonstrates a high voltage experiment and offers some explanation of the physics involved. The creation of a spark is offered as a suggestion, but feel free to follow your own path! You may also want to consider hair raising experiments using a Van de Graaff generator, or the exploration of a fine beam tube. Before you get started, here are a few tips:

• Keep up to date with competition developments by registering: www.cockcroftchallenge.link/register • The competition is open to all. The best UK based school entry will win a Wimshurst generator. • Be adventurous with your science communication style! • Make it personal. Introduce yourself/your group/your school. • Any equipment that you can make safe use of is permitted. • If you do not already have equipment, then why not make some? Here is our video on making a coke can Van de Graaff: https://www.youtube.com/watch?v=EnRbHK8zlyE Guides on producing Lord Kelvin’s Thunderstorm and Wimshurst generators can also be found online. • If your experiment does not work as expected, still make a video  Tell us what is going wrong, give possible solutions. • No equipment, or resources to build with? Then we will also accept entries aimed at communicating an idea found in related literature (example topic: what was known as Cockcroft’s folly?). Particle accelerator based content is especially welcomed. • Include the tag #cockcroft120 somewhere in your video. • Any doubts about the safety of an idea – don’t do it without first seeking expert advice!

Video format and submission We would like to make a compilation video that includes your contribution. To help make this process easier, please submit videos recorded in a 16:9 landscape format (HD preferred, 1920 x 1080 pixels). To submit your video: 1. Upload it to a cloud based service, such as Dropbox or Google Drive. 2. Email a sharing link for the video to [email protected]. Within the email, tell us a little about your group and project. Include your school twitter handle. 3. As well as the above, feel free to upload your video to YouTube, and tweet a link to @livuniphysics with #cockcroft120. Safety:- The University of Liverpool and Cockcroft Institute are unable to accept any responsibility for the safety of participants. Please follow your local rules to minimise the risk to participants. We offer the following as recommendations:

• Apart from the cases of PAT tested Van de Graaff generators or fine beam tubes (used in accordance with manufacturer guidelines), avoid using mains voltages. • If building a device, choose an electrostatic generator design. Be aware of the charge that your device may hold (the coke can design given earlier should pose little risk). • The Institute of Physics offers the following guidance on the safety of Van de Graaff generators (and on safe capacitance limits): http://practicalphysics.org/van-de-graaff-generator-safety.html • Avoid demonstrations that involve participants receiving any kind of electric shock. • Any doubts about the safety of an idea – don’t do it without first seeking expert advice! • Anyone under the age of 18 should complete this activity under the supervision of a teacher or other responsible adult. Judging criteria:- Following the closing date of the competition (July 7th), a panel will select the winning entry based on the following criteria:

• Creativity – how innovative is your video. Try to make it entertaining as well as informative! • Enthusiasm – how enthusiastic your presenters appear to be. • Clarity – how clearly the physics of the selected idea is communicated. • Technical ability – how do you make use of the resources available to you. The Prize:- A single prize of a Wimshurst generator will be offered to the UK school whose entry is deemed to best meet the judging criteria. In the event of a tie, the prize winner will be determined by means of a draw.

Some Rules:-

• Everyone is welcome to participate! Only school based entries are eligible to win the prize of a Wimshurst generator. • Entries that are deemed to promote unsafe practice will not be considered. • Videos must have been produced for this competition. • Where appropriate, permission must have been sought for any third-party materials that appear within your video. • By submitting a video, you are confirming that those appearing in the video, and their legal guardian (if appropriate), have given permission for the video to be shared on social media by the University of Liverpool and Cockcroft Institute. • Your video must be submitted by the end of July 7th (submission steps outlined above). • The decision of the judging panel is final. • These rules may be modified if necessary.

To register, go to: www.CockcroftChallenge.link/register

A copy of this guide, as well as the accompanying poster can be found at: www.CockcroftChallenge.link/guide www.CockcroftChallenge.link/poster Good luck & have fun! Any questions please contact Dr Chris Edmonds [email protected]