Particle Accelerators Focus Group 8

1. Particle Accelerators Focus Group 8 Elisa appiani adriangollerizofernandez chrissarkonak sadiyajamal isaacmuserere International High School Teacher Programme 2019

2. Curriculum & Classroom Connections • None of our curricula explicitly include particle accelerators as part of current teaching practice, however they are easily introduced into a variety of topics that already are. • Throughout kinematics we learn about accelerated motion that would allow students to make calculations in regards to the time and scale needed to achieve the energies in the LHC. • In electromagnetism, in particular through the Lorentz law (ie. The right-hand rule), they will be able to understand how the direction of the magnetic field, and thereby the direction of the magnetic force, influence the trajectory and velocity of the charged particles moving through the accelerator. • Through dynamics students will learn how these forces create an acceleration of the charged particles and with a background in circular motion they will understand how why it is necessary to constantly bend the beam back to a circular trajectory. • The conservation of energy will help students to develop an understanding of why such tremendous energies are required to create new particles (which may be a good place to introduce some basics of the standard model – this is already part of the Spanish curriculum). International High School TeacherProgramme 2019 Focus Group 8

3. Curriculum & Classroom Connections Kinematics Linear motion Circularmotion Electromagnetism Conservationlaws Energy and momentum XXth Century Physics Special Relativity Quantum Mechanics Dynamics http://cds.cern.ch/record/2636343 International High School TeacherProgramme 2019 Focus Group 8

4. Key ideas • Main goal is to accelerate particles or particle-systems as they pass through to a high energy, alter their trajectory (to accommodate for bending through the circular collider), and focus the beam to make collisions more frequent. • By achieving higher energies it becomes possible to create the particles that we seek. For example, the Higgs boson has a high mass and very limited interactions, therefore we need high energies to make it more statistically probable that it will show up in a collision • It is also important to note the LHC is not perfectly circular and so it is always necessary to make corrections to the trajectory of the beam • Compact beams will mean a higher likelihood of collisions in the detectors giving us more data to analyze and that there is a higher probability of discovering new physics International High School TeacherProgramme 2019 Focus Group 8

5. Key ideas • The principle underlying this mechanism is the Lorentz force which describes the force that results from the application of an electromagnetic field on a charged particle (this force will apply to any charged particle or particle-system such as leptons, hadrons, or ions) • The LHC accomplishes this acceleration through large electromagnets that guide two particle beams that travel in opposite directions and collide head-on at the various experiments along the path • A little hand-waving algebra givesus and we can seethat in order to increase the momentum of the particles, and therefore the energies, we must eitherincrease the magnetic field strength or the radius of the accelerator (whichiswhywe are alwaystrying to build largerparticleaccelerators with strongermagnetic fields) International High School TeacherProgramme 2019 Focus Group 8

6. Potentialstudents’ conceptions • Students often will not have a good understanding of particle physics and so they likely won’t be able to relate to the purpose of a particle accelerator • Students will likely have difficulty with understanding the difference between elementary particles and particle systems, therefore they likely won’t understand what is being collided in an accelerator and how new particles are produced • There will also be issues with students’ conceptions of forces and fields as there is often confusion between how these relate to each other • Students have issues with understanding the mass-energy equivalence (ie. ) • There will be misconceptions about what students see in the media in regards to propaganda about what is done here at CERN (ie. Creating black holes, etc) International High School TeacherProgramme 2019 Focus Group 8

7. Potentialstudents’ challenges • There will be challenges with developing student understanding of these ideas as it is not practical to build an LHC in your classroom • There will also be an issue with students developing a solid understanding of these as particle accelerators merge together much of what students learn throughout their high school physics education • Students will also struggle due to the fact that there are experts who struggle with these concepts and so it is impossible to expect our students to have a strong understanding of some of these ideas International High School TeacherProgramme 2019 Focus Group 8

8. Helpfulmaterial and resources • Web-basedresources • https://home.cern/science/accelerators • http://particleadventure.org/accel.html • https://www2.physics.ox.ac.uk/accelerate/resources • Projects and Experiments for the Physicsclassroom • https://www.scienceinschool.org/2014/issue30/accelerator • https://ideas.lego.com/projects/c81dfa92-81f0-45aa-821c-e068d215ce75 • Research Papers • https://www.if.ufrj.br/~pef/producao_academica/artigos/2006_toni_1.pdf • https://iopscience.iop.org/article/10.1088/0031-9120/44/1/011/meta • https://indico.cern.ch/event/803074/attachments/1832320/3001969/PED_51_035001.pdf International High School TeacherProgramme 2019 Focus Group 8

9. Best practiceexample • To gain a better understanding of these concepts, it is possible to build simple particle accelerators for demonstration in your classroom. A simple linear accelerator would include a linear track made of a non-magnetic material (ie. Plastic or aluminum) with magnets, that have steel balls on the far side, spaced throughout. By introducing a small steel ball (our particle for this experiment) the magnetic force will accelerate it towards the first magnet, transferring energy to the furthest ball, accelerating it into the next magnet, and so on. With each transfer of energy the ball leaving the system will be faster than the ball entering the system, effectively demonstrating the concept of a linear particle accelerator. International High School TeacherProgramme 2019

10. Best practiceexample • We can expand on this by replacing the permanent magnets with coils of wire to create small electromagnets and a circuit to coordinate the timing of these (or for more fun, have the students try to hit each band to create an electromagnetic accelerator!). International High School TeacherProgramme 2019 Focus Group 8

11. Best practiceexample https://www.i-cpan.es/concurso3/docs/premio_experimentos.pdf International High School TeacherProgramme 2019 Focus Group 8

12. Are you ready to accelerate some particle systems? International High School TeacherProgramme 2019 Focus Group 8 Thank you!