by Lucile HERVET . Published: 18 October 2013

Profiting from the LHC long shutdown, CERN organized Open Days for the public. The weekend of the 28 and 29 September was a good opportunity to show and explain to the public the purpose of ALICE.


No fewer than 3600 persons had the chance to visit the ALICE cavern and to touch (with the eyes) the experiment. “Despite the rain we had many visitors on Sunday” says Fernando Baltazar, deputy site manager. Around 1900 persons visited the experiment on Sunday and 1400 on Saturday. Taking into account all issues of safety and capabilities, 200 visitors per hour could go in the cavern “ which represents one group of fourteen people every four minutes” explains Fernando Baltazar. The unlucky ones who could not get a ticket through the online booking system had the pleasant surprise to be given the precious pass at the entrance. “We gave a number of extra tickets on both days because we had a margin”.




As an international organization and the biggest particle accelerator in the world, CERN and LHC attract wordwide interest. The Open Days gathered visitors from different countries and transformed the hall of ALICE to a melting pot.


The Hall


Converted to a big exhibition, the hall was the place where visitors could chill over a cup of coffee and learn a little bit more about physics. An LHC dipole magnet was placed for the event in the big hall. Different detectors such as ITS, TOF, DCAL and TRD had exhibition stands where they showed pieces of detectors or whole modules. Some stands were particularly popular with children; such were the cosmic piano and the kids’ corner, where they could build the papercraft of ALICE and make different experiments. The ALICE DAQ and DCS had also stands, where they showed pieces of equipment and video animations and had the opportunity to explain to the public how these complex systems work. Moreover, a ten-minute video was projected in the tent in front of the hall and in the control room. A good way for visitors to apprehend the physics made at ALICE. Inside the permanent exhibition physicist were present, ready to explain the ALICE physics, the different detector technologies and to answer questions; also videos were shown about the different ALICE detectors subtitled in French and English. The Open Days brought closer physicists and the public. Every hour and a half there were presentations in English or French by ALICE physicists. During these the public had the possibility to learn more about ALICE and ask all the questions they wanted. Before going down to the ALICE cavern, visitors could also watch The Digital Graffiti


The DCal



The TOF



The TRD



“ There was a cozy atmosphere all the weekend” confesses Fernando. After hours of discovery, many visitors left with stars in their eyes and souvenirs from the ALICE shop.



The entrance of the site



The team of the ALICE shop


The organization of the event


The success of the Open Days is not due to chance. It is the result of six months of hard work by the organizers. Fernando Baltazar, Arturo Tauro, André Augustinus and Despina Hatzifotiadou were in charge of organizing all the activities at the ALICE site during the Open Days “It was big workload” confesses Arturo Tauro, site manager. A big workload awarded by seeing the smiles of the visitors. “ We came from the north of France to see the biggest particle accelerator of the world, it was a unique opportunity to visit and it was amazing “ says Christophe. “ In terms of numbers we don’t really know the exact number of visitors that came to the experiment but we can estimate that there were two or three times the number of visitors that came down “ says Fernando Baltazar. Do not forget the volunteers without whom “ the event would not have been a success “ adds Arturo Tauro. 140 volunteers participated in the smooth running of the event.



The volunteers


The Open Days at the ALICE experiment were a big success for all the volunteers, the organizers, visitors … and physics.