Author: Gordana Medin

The third Hands-on Edition of the EPS Technology & Innovation Group on optics, powerful lasers, wakefield, plasma accelerators, and intense terahertz pulses, usually organized at CERN in Geneva, this time took place at Petrovac, Montenegro, between July 7 and 9, 2023. 34 students from Poland, Czech Republic, Croatia, and the Balkans were present to build absorption/emission spectroscopy experiments and measure transient currents in state-of-the-art timing detectors developed for CMS and ATLAS High Energy Physics experiments at the HL-LHC in CERN. For the first time, the Workshop was organized in a hybrid mode: in-person and online. Eight students attended the Workshop remotely (from Germany, Spain, Italy, and Portugal).

On the first day, students received introductory lectures. Dusan Medin, representing the local community, gave a talk titled: "Montenegro from West to East" after the Chairperson of the event, Prof. Gordana Lastovicka-Medin from the University of Montenegro welcomed participants. This was followed by a talk given by Markus Nordberg from CERN:  "The importance and role of serendipity in instrumentation innovation".  Massimo Ferrario, senior scientist at INFN Frascati, coordinator of the SPARC_LAB facility at the Frascati INFN Laboratories, where the first FEL driven by a plasma accelerator has been recently demonstrated, brought an outstanding talk: "Accelerating the future". In his fascinating talk, Massimo introduced students to new acceleration technique mechanisms and discussed the most interesting and inspiring results and applications obtained so far, including a description of the new accelerator facility EuPRAXIA based on plasma modules to built in the next decade.  A week later we learned that Massimo was one of the three winners of the prestigious “2023 Enrico Fermi Prize” of the Italian Physical Society (SIF). Congratulations to him!   The president of the EPS and research scientist at CEA (French Commission for Atomic Energy and Alternative Energies), Luc Bergé, who is also a member of the EPS-TIG Board gave a talk on THz Physics. Located between microwaves and optical waves in the electromagnetic spectrum, terahertz waves can now be exploited in molecular spectroscopy from plasma emitters produced by femtosecond laser pulses ionizing gases such as air. Luc Berge firstly overviewed the recent results on the plasma-based terahertz spectroscopy of materials in the context of the project ALTESSE; secondly, new THz radiation originating from the ponderomotively driven in strongly magnetized plasmas was discussed. Mateusz Rebarz, a laser expert from ELI Beamlines (Prague) who was also a demonstrator at the Workshop, introduced students to the potential of the laser facility, ELI ERIC while Prof. Gordana Lastovicka-Medin gave an overview of the R&D on the Low Gain Avalanche Detectors (LGAD) that are now a mature technology and baseline for the timing detectors at the ATLAS and the CMS #experiments at LHC. She also overviewed the main features of the Technique of transient currents (TCT). On the evening of day 1, participants also enjoyed exploring the historical points of Petrovac, local fortress and Gallery.

The second day started with the students' poster presentations. The poster session was aimed to give the students a chance to present the piece of research that they are particularly proud of. At the same time, it was an effective way for students to get to know each other, as well as for the lecturers to get to know the participants of the workshop. Additionally, Anna Grigoryan from Republic of Armenia, participating as the and hands-on training.  Representative of EPS Young Mind (on-line) introduced students to the association “EPS Young Minds”. For the Hands-on training, the two experiments were set: 1) Absorption and emission spectroscopy, and 2) Exploring sensors LGAD with TCT set up. The students were assigned into groups, each being in charge of realizing one subcomponent of a tutorial experiment on said topics. Since eventually all pieces had to be integrated into a complete experiment they did not only have to work on the technical tasks, e.g., assembling the electromechanical and optical setup or establishing the data acquisition, but also on the coordination of their work with other teams, where communication and interpersonal skills in technology and scientific environments was key. Lunch was offered on the beautiful sandy beach where students enjoyed a break while swimming and enjoying the local street food.   In the evening they played some games (such as chess and cards) at the beach and worked on creating presentations about their experiments (focused on reflecting on what they learnt).

On the third day, in the morning, before the resumption of the experiments, each group was tasked with presenting the results obtained the previous day. This allowed the students to think about what they were doing after performing the experiment, and through the presentation to make a recapitulation of what was done and think about the interpretation and meaningfulness of the results. This session was moderated by Eugenio Nappi from INFN Frascati. For us seniors, it was inspiring to watch and observe how the diversity of the “collaborators” backgrounds including their knowledge was brought into and affected the co-developing process. Students had different disciplinary backgrounds and they have been at different academic levels, so, all this brought different but necessary pieces necessary for them to overtake personal limits and grow up with a new skill needed not only for the sake of intellectual development but also to grow as people.  All over it was very successful event, with a lot of fun!

Images by Gordana Medin and Nevena Živković