On the 21st of November 2015, 1.903 people attended the ALBA Open Day. On its 4th edition, the event has become a successful activity among families and general public. The activities were related to the celebration of the International Year of Light 2015.

Following an itinerary of about two hours, the nearly 2,000 visitors had the chance to discover what a synchrotron is, how it works and which its main applications are.

The event was a big science party where many different activities were organized for all ages. The visit was organized around a circuit composed by different exhibition areas. The participants were able to see the equipments where the electrons pass through or those used for manipulating the synchrotron light, as well as to observe the interior of the accelerator's tunnel which was opened on that occasion. Besides, several demonstrations were organized to make the experience more interactive and direct: a small particle accelerator for explaining the Lorentz force, a laser demonstration for showing the diffraction technique, explaining how different light sources are perceived, discovering your real height with micrometer precision, etc. The kids could follow a treasure hunt around the facility that ended up with a diploma ceremony. The most prominent surprise was a music band, composed by members of the ALBA staff, who adapted some popular songs for explaining what a synchrotron is. This year, another of the novelties was the celebration of four conferences for giving complementary information about particle accelerators (by Caterina Biscari), the nature of light (Salvador Ferrer), the science behind a synchrotron (Josep Nicolàs) and how a synchrotron works (Montse Pont).

"The ALBA Open Day has been a day of celebration. I am sure that scientific vocations were strengthened or born in many of the young people visiting us and we are very proud of it", says Caterina Biscari, director of the ALBA Synchrotron.

The visitors were very active at the social media, uploading images and comments followed by the hashtag #ALBAOpenDay.

The ALBA Open Day was held thanks to the contribution of 78 volunteers from the ALBA Synchrotron who helped in the coordination of the event and also giving explanations and informing the visitors. It is also worth mentioning the support from Civil Protection, who generously offered their experience during the whole day.

Like in previous editions, the tickets for the ALBA Open Day ran out two weeks before the event. The access was free however required booking through the internet.

The ALBA Synchrotron has developed an outreach programme, which includes the organization of the ALBA Open Day as well as guided tours inside the facility. Both activities together welcome more than 5,000 visitors every year.

The ALBA Open Day was organized with the support of the Spanish Ministry of Economy and Competitiveness, the Catalan Government and the sponsorship of La Caixa Foundation.

Left, view of the experimental hall with the Accelerators exhibition area. Next, one moment during the music performance and a girl completing the treasure hunt.

@Pepo Segura - Sincrotrón ALBA

Diploma photo at the Kids area. Next, a volunteer explains the difference between the magnets used in ALBA.  @Pepo Segura - Sincrotrón ALBA