1 General FAQ's for BL4S

Are there any costs involved in taking part in the competition?

There are no fees or anything similar, taking part is completely free. For the winning teams, BL4S will cover the full costs of the winners' participation to the competition, including travel, accommodation and three meals per day.

Who is eligible?

High-school students from all over the world aged 16 and older on the first day of their visit at the laboratory (usually September or October of the year of the competition) are eligible. Younger students may be part of a team, but they cannot be invited on site in case of winning the competition. Participants must be in high/secondary school when submitting the proposal.

Is it possible for students under the age of 16 to participate in the competition?

Yes, but... For the participation to the competition there is no age limit. Students under the age of 16 can be members of a team and will receive certificates. The only limitation is that if team wins, only students that are at least 16 years old in September can be invited.

Who can be a team coach?

The team coach needs to be an adult. Very often this person is a teacher at the students’ school, but this is not mandatory. The coach can be a mentor from another institution or even a parent or student at university. Please keep in mind that, in case of winning the competition, the team coach will need to obtain the consent of the parents of all minors in the team, and probably also of the school(s) the team members are erolled in.

What is being offered?

2018 edition and before
A chance to win a trip to CERN and conduct a student-led particle physics experiment at the world’s largest particle physics laboratory. Before coming to CERN the winning teams will have the opportunity to work together with CERN scientists on their ideas on how to use the beam line and plan out a particle physics experiment. For short-listed teams there will be additional prizes such as CosmicPi particle detectors and t-shirts. All participants will receive a certificate.

from 2019 edition to 2021 edition
A chance to win a trip to DESY and conduct a student-led particle physics experiment at a world-leading accelerator centre. Before coming to DESY the winning teams will have the opportunity to work together with DESY and/or CERN scientists on their ideas on how to use the beam line and plan out a particle physics experiment. For shortlisted teams there will be additional prizes. All participants will receive a certificate. Please note that all prizes on this website are indicative. CERN reserves the right to modify or exchange the prize should it so require. CERN also does not bear any responsibilities for lost prizes during the course of shipping.

Where will it happen?

In 2014 - 2018 at CERN’s fixed-target beam facilities, near Geneva, Switzerland.
2019 - 2021 at DESY in Hamburg, Germany.

When will it happen?

The registration opens the year before the competition. in 2021 proposals can be submitted until the deadline: midnight CET on 15 April. The winning teams are notified in June. The winning teams will be invited to the research laboratory in September and/or October.

Why is CERN doing this?

This is an ideal opportunity to expose today’s cutting-edge physics to tomorrow’s scientists. The Beamline for Schools competition began in 2014 to celebrate CERN’s 60th Anniversary and had already some successful runs.

How do we enter?

Have a look how to apply  and at our useful documents and follow the instructions you’ll find there. Remember, you must submit your written proposal by midnight CET on 15 April 2021.

Who can make a team?

Students can be from a single school, from multiple classes, from different schools or even countries. Each team has to have at least 5 members and has to be represented by an adult coach.

How many people per team?

The minimum is 5. There is no upper limit but for the winners a maximum of nine students will be invited, with one or two adults acting as coaches. Data transmission and web link-ups will allow additional students to participate and analyse data remotely.

Can we use the logos in our written proposal and video?

The CERN and DESY logo are legally protected and any use by third parties is forbidden. However, the BL4S logo could be used if desired.

How do we submit videos?

Publish your video on a video platform such as Vimeo or YouTube and submit your full proposal via the submission form including the link to your video. Note that the video in 2021 is not mandatory, but encouraged.

In what languages can we submit our proposals?

All submissions must be made in English. Please note that we cannot consider submissions made in other languages. 

What kind of experiments can we do?

It is up to you and your team how you want to use the beam line facility. The beam line will be fully equipped; with a pre-determined set of detectors that you can choose from to design your own experiment. Have a look at the beam and detector document in our useful documents to learn more about the beam line facilities and its possibilities. In addition to the equipment provided, you may also bring your own detectors (maybe you can even build one yourself as previous winners have done).

How are the proposals judged?

We will evaluate the proposals on these criteria:

  • The feasibility of the experiment
  • The ability to follow the scientific method
  • The motivation of the experiment and why you want to come to DESY
  • The creativity of the experiment

We are not expecting fully developed experimental proposals. Your motivation and creativity are very important to us.

We don’t know about particle physics. Is this a problem?

All students enthusiastic about learning are encouraged to participate. We recognize that most students have little to no experience with particle physics when they begin the competition, but will learn as they progress through the competition. Volunteers are available for providing help to the team. In addition CERN’s website has several resources for introducing particle physics.

Who will evaluate our experiment proposal?

A group of physicists and engineers will pre-select the proposals. From 2014-2018 the short-listed experiments were sent to the SPSC, the committee that validates all proposals for experiments at the laboratory’s Super Proton Synchrotron (SPS) and Proton Synchrotron (PS) accelerators, which selected the winners. From 2019 on a joined committee of DESY and CERN scientists select the winners.


What is DESY and what is DESY II?

DESY, like CERN, is an acronym. It stands for "Deutsches Elektronen Synchrotron” (German electron synchrotron). Originally it was the name of an accelerator. Today the acronym refers to a large research institute that operates many different accelerators. For more information please visit this website. The Acronym “DESY II” refers to the second generation electron / positron accelerator of DESY.

The beams at DESY ONLY provide electrons and positrons. What can we do with them?

We have collected many ideas for experiments. You can find them in our example experiments document in our useful documents It is perfectly OK if you take one of them as the basis of your proposal. They can be refined in many ways. You can, of course, also use your own creativity to think about an experiment. The contact persons are happy to help you in case of questions.

What is the typical energy of the electron/positron beam provided by DESY II?

The DESY II particle beam production process is described in our beam and detector document  available here useful documents. The energy of the electrons/positrons in the beam spans from 500 MeV to 6 GeV (eV: Electron Volt, more explanations in the technical document), and you can select a value with a precision of 0.15 GeV. This is a crucial information to plan your experiments because you won't be able to study a phenomenon that requires a particle energy lower or higher than these values. Keep in mind that the particles are in the relativistic regimes and that the beam line provides mostly one particle at a time, it lends itself well to experiments that focus on effects that can be seen with individual high speed particles.

Can atoms or molecules be accelerated at DESY II?

No. DESY II can accelerate only electrons. When they hit a target, they produce, via one intermediate step, a secondary beam composed of electrons and positrons (the anti-matter twins of electrons). Additional details can be found in our beam and detector document in our useful documents.

What are the professional physicists at DESY doing with the beam?

Most of the time we use the beam to test prototypes of new detectors before they are installed in the large experiments. While some of these detectors are quite complicated we sometimes also use very simple detectors that can even be built at a school. Examples are scintillators or silicon detectors based on commercial image sensors.

Can we bring our own equipment/detectors to the beam?

In principle, this is possible, but we have to evaluate it individually, in particular if the material has potential hazards (e.g. fire, toxicity, etc..). So please contact us during your early planning phase.

Can we control the collimators?

Yes, the collimators can be controlled. Please note that if you close the collimators in order to select a more narrow spectrum of particle momenta, you reduce at the same time the number of particles that enter into the experimental zone.

Do we have to prepare in advance the data acquisition and analysis softwares?

No, the winning teams will receive full support to set-up their data acquisition system and to start their data analysis during the experiment preparation time, and during their stay at DESY.

Is it feasible to recombine molecules (i.e. helium) at DESY II?

No. Our professional physicists just managed to produce hydrogen from protons and electrons. Recombining helium is more difficult. In addition the beam does not contain alpha particles. Its exact composition can be found in our beam and detector document in our useful documents.

Can we get an antimatter beam?

Yes. The beam at DESY II contains anti-electrons as described in our beam and detector document in our useful documents.

Is it possible to use a virus sample or bacteria in the experiment? What about other biological material?

Unfortunately is not possible to irradiate any kind of samples that contain living organisms including seeds, roots or cells. Inactive organic material such as wood or leather can be exposed to the beam.

Can we find a Higgs boson?

No. Higgs bosons can only be observed in the Large Hadron Collider (LHC) at CERN, the largest accelerator in the world. The beams at DESY don’t have enough energy for the production of Higgs particles.

I still have some technical questions. Who can I ask for help?

Please feel free to send us your questions to bl4s.team@cern.ch. For obtaining quickly the most useful answer, you should include some short information about your ideas/your proposal and how our answers would influence your experiment.