15. Extreme Energy Events (EEE) - Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi

Extreme Energy Events (EEE) – La Scienza nelle Scuole

In short

The Extreme Energy Events (EEE) Project combines research and scientific dissemination, representing a unique example in the world. Through a network of 59 Multi-Gap Resistive Plate Chambers telescopes, distributed throughout the national territory inside high schools and research institutes, it offers the possibility to study the flux of secondary cosmic rays and to detect, over a region of hundreds of km, the possible appearance of extended events. About a thousand students per year are involved in all stages of the process, from the construction of telescopes to the analysis of the collected data, and participate in videoconferences, workshops, and masterclasses. The know-how developed as part of this project made possible the creation of sophisticated, portable cosmic-ray detectors, used in the PolarQuest2018 and PolarquEEEst-2019 expeditions. These detectors will make it possible to carry out new experimental measurements at arctic latitudes.

The Extreme Energy Events (EEE) Project is a joint effort between CREF and INFN. It is a scientific experiment with a twofold goal: on the one hand, it is devoted to the study of the secondary cosmic radiation at the ground level and on the other to the dissemination of science in high schools. The peculiarity of the EEE project is its geographical extension: The detectors are distributed throughout the whole Italian territory. EEE is also the largest experiment—in terms of total surface—based on the Multi-Gap Resistive Plate Chamber (MRPC) technology. However, the most relevant feature characterizing the uniqueness of this project is represented by the participation of secondary school students, who are directly and actively involved in all the phases of the experiment.

The EEE network currently includes 60 cosmic muon tracking telescopes, each consisting of three MPRC detectors (arranged one above the other at a distance of 50 cm). The MRPC detectors are built at CERN by teams of teachers and students and installed in high schools, universities and public research centers (CREF, INFN sections), spread out across Italy. The data acquired by the individual telescopes are used to study the characteristics of the local flux of secondary cosmic rays such as variations of flux as a function of environmental parameters—temperature and atmospheric pressure—or parameters associated with solar events, or absorption effects due to nearby or more distant obstacles (e.g., the Moon or the Sun), or to the east–west asymmetry.

The EEE Project telescopes are equipped with a GPS receiver that associates an absolute time to each detected cosmic ray, providing time synchronization between various telescopes. Thanks to the synchronization, it is possible to study extensive air showers and then search for events in time coincidence between stations at distances up to a few km. The detectors are distributed throughout Italy in clusters or in single stations. The large area covered by the network provides the possibility, unique in the world, to search for correlations between stations located hundreds of km apart. Any correlation signal from a distant telescope would be a direct indication of the production mechanisms hypothesized, but not yet experimentally verified, such as the Gerasimova–Zatsepin effect. The EEE experiment can provide a contribution in multi-messenger astronomy which is based on the simultaneous detection of different signals produced by the same astrophysical object or phenomenon: from photons, to charged and neutral particles, or gravitational waves. The EEE network can detect anomalies in the cosmic ray flux simultaneous to events of astrophysical interest such as, for example, the emission of gravitational waves or Supernovae explosions.

The EEE Project plays, in an innovative way, an important role in the dissemination of scientific culture, involving students and teachers of about one hundred Italian high schools in all phases of the experiment: from the construction of the detectors at CERN to their maintenance once installed in the schools, as well as in the data acquisition and analysis phase. Currently, more than a thousand students from all over Italy participate in the EEE project each year.

Data Acquisition

Since 2014, the experiment has been organized in coordinated phases of data taking called Run.

The duration of each Run coincides temporally with the school year. During the Run, all the telescopes remain in data-acquisition mode, and the data are directly transferred to the CNAF storage and analysis centre in Bologna. During the Run all the participants work actively to ensure the maximum efficiency of the network. At the end of Run 5, in may 2019, with more than 100 billion reconstructed tracks have been collected a maintenance phase of the EEE telescopes began as the stations have been in operation for several years. This maintenance was divided into a series of interventions involving all the telescopes devoted to the improvement of the performance of any single station and, consequently, of the whole network. The maintenance phase of the telescopes was interrupted due to the beginning of Covid-19 pandemic which led to the interruption of all activities in presence. Due to the protraction of the emergency the restart of maintenance activities on the telescopes installed in schools and the subsequent of the data acquisition phase are scheduled to start in fall 2021.

Upgrade of the EEE Network

Because of the Covid-19 Pandemic also the network upgrade phase has been interrupted. Till that moment a total of 50 new MRPC detectors were built at CERN in the last years. Students and teachers from Italian high schools participating to the project always carry out the construction of the chambers. The new detectors will be used either for the installation of new EEE stations or to replace old chambers. The activity will continue during the next years. In October 2019, on the occasion of the opening of the institutional headquarters of the Enrico Fermi Research Center in the historic building in via Panisperna, three of these new built detectors were used to install a telescope at CREF that started its operation during the opening event. It had been equipped to be usable also for demonstration purposes, as part of the guided tours of the “Fermi Museum” housed in the historic building and for outreach events. Further network upgrades and maintenance activities include the study of new gas mixtures to be used in the detectors to improve their performance and to limit supply costs. Studies intended to identify alternative solutions for the detector power-supply system are also on going. Completion of the installations started at the end of 2019 is foreseen by fall 2021 provided the improvement of the pandemic emergency.

Data Analysis and Publications

In 2020, the data analysis activities of the EEE Project continued. The results of the analysis of the data acquired during the PolaQuest2018 mission regarding the measurement, with unprecedented precision, of the flux of cosmic charged particles at sea level in a latitude interval between 66 ° and 82 ° N. A further analysis on the variation of the cosmic ray flux with latitude in a wider latitudinal interval will be finalized in 2021. The detectors of the PolarQuest Mission, now permanently installed in the Svalbard Islands, are acquiring data since summer 2019; the data will be used for further analysis also related to the study of extensive air showers. The analysis to search for long distance coincidences (LDC) between stations hundreds of km apart is continuing; the EEE network has unique characteristics particularly suitable for this analysis. Finally, the development of Monte Carlo simulations of the detectors of the EEE Project and of the environments that host them to obtain an increasingly accurate evaluation of the efficiencies of the individual telescopes and systematic uncertainties continued and the results were merged into a publication in an international journal; the simulation tools will be extended for the study of PolarQuEEEst detectors. The members of the collaboration participated in national and international conferences and the contributions have merged into the publications of the proceedings of the conferences themselves.

PolarquEEEst

The experience of the PolarQuest2018 expedition (http://www.polarquest2018.org), which sparked the EEE collaboration to the design and construction of a cosmic ray detector installed on board the ship Nanuq, continued in 2019 with fresh measurements of cosmic ray flux. The POLA-01 detector, which showed high reliability and efficiency during the PolarQuest2018 mission, was used to continue the cosmic-ray flux measurement campaign in Italy (Bologna, Cosenza, Erice, Catania), in Germany, and in Switzerland. These measurements allowed the study of the variation of the cosmic ray flux as a function of latitude. In May 2019, the POLA-01, POLA-03, and POLA-04 detectors (the latter built in the first months of 2019) were installed at the Ny Alesund international scientific station, located in the Svalbard Islands, while POLA-02 was brought back to Italy for maintenance and for its future installation on board a boat for a new measurement campaign. The detectors installed at ny Alesund, in collaboration with CNR, were taking data (continuosly since may 2019) that will be used to study the cosmic ray flux on a large time scale, in a latitudinal region where there are have not been any experimental measurements. Having three detectors at a distance of about 1 km from each other will make it possible to study extended showers at arctic latitudes.

Dissemination

The EEE Project was conceived to bring a real scientific experiment inside Italian high schools. During the school year, about 1,000 students are directly involved in the experiment. In the schools where EEE telescopes are installed, the students are responsible for the proper operation of the detector. The work is organized locally and supervised by the researchers involved in the EEE Project. The schools participating in the experiment can access the data acquired by the network even if they do not have a telescope itself: All schools are therefore engaged in data-analysis activities, both independently and with the supervision of scientific personnel. The EEE collaboration organizes monthly meetings via a videoconference system (forming more than 100 connections with schools) during which students can participate in masterclasses and present their work to the entire collaboration. The 2020 Covid-19 Pandemic prevented the continuation of experimental activities on telescopes and made it impossible to organize the usual in-person workshops dedicated to the discussion of the project. For this reason, in 2020 and 2021 various remote seminars were organized on various scientific topics directly or not connected to EEE: the “Cherenkov Telescope Array” seminar was followed by about 400 students and teachers; the seminars “Quantum Mechanics” and “Female scientific thought. Our ancestors ”and“ Physics applied to cultural heritage ”, were followed by about 500 participants. On November 4, 2020, the online version of the International Cosmic Day—the best-known educational event in the field of cosmic rays, organized by the Desy research center. Hundreds of students of the EEE Project joined the initiative, participating in the day’s work, confirming the internationalization process underway in the EEE Project.

Recent Publications

[1] M. Abbrescia, C. Avanzini, L. Baldini, R. B. Ferroli, L. Batignani, M. Battaglieri,S. Boi, E. Bossini, F. Carnesecchi, A. Chiavassa, et al., First results from the upgrade of the extreme energy events experiment. Journal of Instrumentation, 14(08):C08005, 2019.
[2] M. Abbrescia, C. Avanzini, L. Baldini, R. B. Ferroli, L. Batignani, M. Battaglieri, S.Boi, E. Bossini, F. Carnesecchi, C. Cicalo, et al., The eee mrpc telescopes as tracking tools to monitor building stability with cosmic muons, Journal of Instrumentation, 14(06):P06035, 2019.
[3] M. Abbrescia et al. Gli studenti del progetto eee sulle orme di eratostene per la misura del raggio della terra, Giornale di Fisica , 60(107), 2019.
[4] Cicalò et al. The extreme energy events experiment, Iìin ICRC , volume 36, page 389,2019.
[5] D. De Gruttola, M. Abbrescia, C. Avanzini, L. Baldini, R. B. Ferroli, G. Batignani, M.Battaglieri, S. Boi, E. Bossini, F. Carnesecchi, et al., Performance of the multigap resistive plate chambers of the extreme energy events project, Journal of Instrumentation, 14(05):C05022, 2019.
[6] Garbini M. et. al. (EEE Collaboration), Performance of the multigap resistive plate chambers of the Extreme Energy Eventsp project, Nuclear Instruments and Methods in Physics Research A936 (2019) 474, doi: 10.1016/J.nima.2018.09.007.
[7] M. P. Panetta, M. Abbrescia, C. Avanzini, R. B. Ferroli, L. Baldini, G. Batignani, M. Battaglieri, S. Boi, E. Bossini, F. Carnesecchi, et al., The new trigger/gps module for the eee project, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 936:376–377, 2019.
[8] C. Pellegrino, F. Noferini, M. Abbrescia, C. Avanzini, L. Baldini, R. Baldini Ferroli, G. Batignani, M. Battaglieri, S. Boi, E. Bossini, et al., First results from polarqueeest, in ICRC , volume 36, page 371, 2019.
[9] S. Pisano, M. Abbrescia, C. Avanzini, L. Baldini, R. B. Ferroli, L. Batignani, M. Battaglieri, S. Boi, E. Bossini, F. Carnesecchi, et al. New eco-gas mixtures for the extreme energy events mrpcs: results and plans, Journal of Instrumentation, 14(08):C08008, 2019.

[10] M. Trimarchi, M. Abbrescia, C. Avanzini, L. Baldini, R. B. Ferroli, L. Batignani, M. Battaglieri, S. Boi, E. Bossini, F. Carnesecchi, et al., Test of new eco-gas mixtures for the multigap resistive plate chambers of the eee project, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 936:493–494, 2019.

Project Contact Person

Marco Garbini

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