The nucleus and elementary particle outreach center operates within Experimental nuclear and particle center of the Faculty of Physics (FP) at Vilnius University (VU). It organizes educational activities for the general public. High school students and their teachers are welcome to visit our center, to take part in particle physics experiments, attend a lecture on CERN activities and research, or participate in a video bridge. Students will deepen their knowledge in the field of nuclear and elementary particles, learn scientific work and learn how to apply their knowledge in a new situation. Teachers can raise their qualifications by sharing experiences and ideas.
Our Center aims to attract students to the field of physics, to motivate them by lectures about particle physics, simple and easy experiments. Our current services for school teachers and students are:
Day at the Center
Program “Day at the Center” offers a unique opportunity for high school students (16-18 years old) and their teachers to get familiar with the research conducted at CERN. During this activity, students and their teachers will visit the VU CERN research facilities and get acquainted with the research performed in Lithuania, carry out an experiment at the VU Physics Training Laboratory and the Physics Research Center. For the optimal use of time, students needs to be familiar with the educational material provided on this website before the arrival. Questionnaires given before, during, and after the visit allow the Center to collect empirical survey data on teachers and students experiences.
Teachers who wants to visit the Center, should get acquainted with:
Before – excursion planning and the preparation of students for the trip
During - information important for the teachers during the activity
After - suggestions and recommendations to the organizers of the "Day at the Center"
Students should be acquainted with theoretical basis for practical work.
1. Absorption of alpha and beta particles in material: during the work, alpha and beta absorption curves are measured when the particles are absorbed by various materials. The action ranges of the particles are established according to the data points; in the case of alpha particles, the energy of particles is determined. The obtained results are compared with known values, which are presented in the literature or calculated according to the empirical formulas. The absorption properties of alpha and beta particles are compared.
2. Absorption of gamma rays in material: gamma radiation absorption curves are measured at different energies using a variety of absorbents. The regularities of gamma radiation interaction with the material are checked: 1) exponential law of attenuation, 2) the decrease of attenuation coefficient with increasing energy of gamma quantum; 3) the increase of the attenuation coefficient with increasing atomic number of material.
3. Measurement of alpha particles energy: alpha particles energy spectrum is measured using a semiconductor spectrometer; some characteristics of the alpha particles energy spectrum and its measurement method (discrete nature of particle energy, typical alpha particles energy, proportionality of the average amplitude of the detector‘s pulse to the energy of the particle) are investigated, the influence of the interaction of alpha particles with the material on the shape of particle spectrum is studied (the decrease of the average energy of particles and the spread of energy distribution as they penetrate the absorber).
4. Gamma spectrum measurement: the properties of gamma spectrum (peak of absolute absorption, continuous Compton spectrum) are investigated. Introduction to the gamma spectrometer calibration methodology and photon energy measurement methodology.
Students need to know what alpha, beta, and gamma radiation is, as well as their action range. After registering and obtaining a registration confirmation, descriptions of the chosen workshops will be sent to teachers.
"Day at the Center" Programme:
10.00 – 11.00 Lecture “The Big Bang and the Large Hadron Collider at CERN”, prof. E. Norvaišas. VU ITPA.
11.10 – 12.00 Practical activity “Particles traces”, assoc. Prof. A. Acus, dr. A. Mekys
12.00 – 13.00 Lunch break
13.00 – 14.00 Lecture “CERN and Lithuania”
14.30 – 16.00 Practical activities VU FP, assoc. prof. A. Poškus
Questionnaires for teachers (coming soon)
Prof. E. Norvaišas (VU ITPA): The Big Bang and the Large Hadron Collider at CERN
Cosmologists – scientists who are interested in the origin and evolution of our universe – agree: it all started with the Big Bang. A vast amount of energy was concentrated in a tiny volume which expanded along with space. From elementary particles and atoms to planets, stars, and galaxies – everything that our universe consists of – were created during this process. By studying elementary particles, physicists have built a 27-km-length Large Hadron Collider at the CERN laboratory near Geneva, which successfully reproduces the density and other conditions that are close to those that existed during the first seconds of the Big Bang.
Prof. E. Norvaišas (VU ITPA): Antimatter in Large Hadron Collider at CERN
In 1928, English physicist-theoretician Paul Dirac “with the tip of his pen” predicted the existence of the antiparticle of electron – positron. Later, the antiparticles of electron, proton, and other particles were detected experimentally. All this merged into a symmetrical view of the physical world. However, the universe we are able to observe solely consists of matter. This lecture will try to answer the following question: where did all the antimatter disappear after the Big Bang? The properties of antimatter will be discussed, as well as the „factory“ of antimatter operating at CERN will be reviewed.
Prof. E. Norvaišas (VU ITPA): How does it work: the largest microscope in the World – the Large Hadron Collider
The Large Hadron Collider at the CERN laboratory near Geneva restarted its activities. During the pause that took one and a half year the collider was renewed to accelerate the opposite proton flows up to 13 teraelectronvolts. Prior to this upgrade, the protons reached the energy of 8 teraelectronvolts, which in turn allowed to discover one of the most “hunted” elementary particles – the Higgs boson. The lecture discusses how the world's largest 27-km-length collider, engineered by the international team of 10,000 scientists, actually works, records the elementary particles, and what are the future expectations..
Prof. E. Norvaišas (VU ITPA): Will the black hole eat CERN and all of us?
CERN is the European Nuclear Research Laboratory in Geneva, which operates the largest and most powerful proton collider in the world. The opposite proton flows are allowed to collide creating a high energy concentration in a tiny volume of space, which is very similar to the conditions that existed during the very first seconds of the Big Bang. Collision of protons generates a variety of different particles. Maybe a tiny black hole, formed during this process, will eat CERN and the whole Earth? What is a black hole? These questions will be answered in a lecture.
After a brief introduction about the history of the Wilson cloud chamber, students are taught how to create it. Every small group of 2-4 participants creates its own cloud chamber. Most of the workshop‘s time is spent monitoring the particles traces in the chamber and capturing them in photos and videos. The task is to identify the particles captured in the photos and videos according to the provided particles identification patterns.
Experiment takes 60-75 minutes.
In case you are a teacher, who has been approved to visit the “Particles traces” activity, please read the practical information about the performed experiment.
“Particles traces” in your classroom
If you are interested in creating Wilson chamber at your own classroom, please have a look at this do-it-yourself manual.
Information for teachers
It is worth mentioning that elementary particles like positron and muon were discovered with the help of Wilson chamber (the Nobel Prizes for these discoveries were dedicated in 1932 and 1936, respectively). Nowadays, however, Wilson chamber is mostly used for educational purposes, except for the CLOUD experiment in CERN, where a specialized cloud chamber is still utilized to explore the possible connection between the galactic cosmic rays and formation of the clouds.
Students construct Wilson chamber using dry ice and isopropanol to visualize cosmic particles and natural radiation, capture and study different traces, identify particles.
Desired students‘ knowledge
Different particle types: protons, neutrons, electrons, photons, helium nuclei (alpha particles), muons, positrons, neutrinos, natural radiation (alpha, beta, gamma), different states of matter, ionization and condensation (optional).
The things the students will learn
- How to construct Wilson chamber and identify some particular particles within it
- Where do these particles come from
- Recommended age: 16 years or more. The younger participants must be accompanied by an adult.
Group size: minimum 12 people, 24 at most.
Experiments at the Center:
- Absorption of alpha particles and electrons. Experiment No. 1
- Attenuation of gamma rays. Experiment No. 2
- Study of the alpha-energies of radium. Experiment No. 3
- Measuring the spectrum of gamma radiation. Experiment No. 4
Activities at school:
- Avogadro constant (theoretical task)
- Measurement of the molecular size of oil (experiment)