Frascati National Laboratories Research Articles

The EuAPS Betatron Radiation Source: Status Update and Photon Science Perspectives

The EuPRAXIA EU project is at the forefront of advancing particle accelerator research and the development of photon sources through innovative plasma acceleration approaches. Within this framework, the EuAPS project aims to exploit laser wakefield acceleration to build and operate a betatron radiation source at the INFN Frascati National Laboratory. The EuAPS source will provide femtosecond X-ray pulses in the spectral region between about 1 and 10 keV, unlocking a realm of experimental ultrafast methodologies encompassing diverse imaging and X-ray spectroscopy techniques. This paper presents a description of the EuAPS betatron source, including simulations of the photon beam parameters, outlines the preliminary design of the dedicated photon beamline, and provides an insightful overview of its photon science applications.

Design of Machine Learning-Based Algorithms for Virtualized Diagnostic on SPARC_LAB Accelerator

Machine learning deals with creating algorithms capable of learning from the provided data. These systems have a wide range of applications and can also be a valuable tool for scientific research, which in recent years has been focused on finding new diagnostic techniques for particle accelerator beams. In this context, SPARC_LAB is a facility located at the Frascati National Laboratories of INFN, where the progress of beam diagnostics is one of the main developments of the entire project. With this in mind, we aim to present the design of two neural networks aimed at predicting the spot size of the electron beam of the plasma-based accelerator at SPARC_LAB, which powers an undulator for the generation of an X-ray free electron laser (XFEL). Data-driven algorithms use two different data preprocessing techniques, namely an autoencoder neural network and PCA. With both approaches, the predicted measurements can be obtained with an acceptable margin of error and most importantly without activating the accelerator, thus saving time, even compared to a simulator that can produce the same result but much more slowly. The goal is to lay the groundwork for creating a digital twin of linac and conducting virtualized diagnostics using an innovative approach.

The future search for low-frequency axions and new physics with the FLASH resonant cavity experiment at Frascati National Laboratories

We present a proposal for a new experiment, the FINUDA magnet for Light Axion SearcH (FLASH), a large resonant-cavity haloscope in a high static magnetic field which is planned to probe new physics in the form of dark matter (DM) axions, scalar fields, chameleons, hidden photons, as well as high frequency gravitational waves (GWs). Concerning the QCD axion, FLASH will search for these particles as the DM in the mass range (0.49–1.49)μeV, thus filling the mass gap between the ranges covered by other planned searches. A dedicated Microstrip SQUID operating at ultra-cryogenic temperatures will amplify the signal. The frequency range accessible overlaps with the Very High Frequency (VHF) range of the radio wave spectrum and allows for a search in GWs in the frequency range (100–300)MHz. The experiment will make use of the cryogenic plant and magnet of the FINUDA experiment at INFN Frascati National Laboratories near Rome (Italy); the operations needed to restore the functionalities of the apparatus are currently underway. We present the setup of the experiment and the sensitivity forecasts for the detection of axions, scalar fields, chameleons, hidden photons, and GWs.

Performance evaluation of an Ultra-Fast IR Detector for Astronomy Transients

In this work, we present the design of an ultra-fast IR (InfraRed) detector for the search of astronomical transients. Time-domain astronomy is a field in continuous growth in the last years, with interest in detectors with nanosecond performance, in order to observe potential fast transients with the time scale of GRBs (Gamma Ray Bursts) and FRBs (Fast Radio Bursts). An ultra-fast temporal detector based on HgCdTe photoconductors is under development in Italy, at the Frascati National Laboratory of the National Institute of Nuclear Physics, by tests at SINBAD, the DAFNE infrared beamline. The detector will be used for mid-IR observations together with a ground-based reflecting telescope or launched on a scientific balloon.

Commissioning and first results of an x-band LLRF system for TEX test facility at LNF-INFN

In the framework of LATINO project (Laboratory in Advanced Technologies for INnOvation) funded by Lazio regional government, the commissioning of the TEst stand for X-band (TEX) facility has started in 2021 at Frascati National Laboratories of INFN. Born as a collaboration with CERN to test high gradient accelerating structures, during 2022 TEX aims at feeding the first EuPRAXIA@SPARC_LAB X-band structure prototype. During 2021 the commissioning has been successfully carried out up to 48 MW. The power unit is driven by an X-band low level RF system, that employs a commercial S-band (2.856 GHz) Libera digital LLRF (manufactured by Instrumentation Technologies), with an up/down conversion stage and a reference generation and distribution system able to produce coherent frequencies for the American S-band and European X-band (11.994 GHz), both designed and realized at LNF. The performance of the system, with a particular focus on amplitude and phase resolution, together with klystron and driver amplifier jitter measurements, will be reviewed in this paper. Moreover, considerations on its suitability and main limitations in view of EuPRAXIA@SPARC_LAB project will be discussed.

Using Artificial Intelligence in the Reconstruction of Signals from the PADME Electromagnetic Calorimeter

The PADME apparatus was built at the Frascati National Laboratory of INFN to search for a dark photon (A′) produced via the process e+e−→A′γ. The central component of the PADME detector is an electromagnetic calorimeter composed of 616 BGO crystals dedicated to the measurement of the energy and position of the final state photons. The high beam particle multiplicity over a short bunch duration requires reliable identification and measurement of overlapping signals. A regression machine-learning-based algorithm has been developed to disentangle with high efficiency close-in-time events and precisely reconstruct the amplitude of the hits and the time with sub-nanosecond resolution. The performance of the algorithm and the sequence of improvements leading to the achieved results are presented and discussed.

Crystal slow extraction of positrons from the Frascati DA Φ NE collider

The slow high-efficiency extraction from a ring positron accelerator (SHERPA) project's aim is to develop an efficient technique to extract a positron beam from one of the accelerator rings composing the $\mathrm{DA}\mathrm{\ensuremath{\Phi}}\mathrm{NE}$ complex at the Frascati National Laboratory of INFN, setting up a new beam line able to deliver positron spills of O(ms) length, excellent beam energy spread and emittance. The most common approach to slowly extract from a ring is to increase betatron oscillations approaching the third order tune resonance to gradually eject particles from the circulating beam. SHERPA proposes a paradigm change for lepton machines using coherent processes in bent crystals to kick out positrons from the ring, a cheaper and less complex alternative. A description of this innovative nonresonant extraction technique is reported in this manuscript, including its performance preliminary estimation.

The reserach activity of the Frascati Laboratory

The Frascati National Laboratory (LNF) is the largest and the oldest among the National Laboratories of the Italian Institute for Nuclear Physics (INFN). Since its foundation in 1954, it has been devoted to two main activities: the development, construction and operation of particle accelerators; the design and construction of forefront detectors for particle, nuclear and astroparticle physics. The research program of LNF is focused on fundamental research, but interdisciplinary activity has grown of importance along the years, with a perfect balance between internal and external activities. The scientific program taking place at LNF, at present, is still centered on the DAΦNE complex, but in the last years, a second accelerator infrastructure, SPARC\\_LAB, devoted to the study and development of new technique of particle acceleration is marking the path toward the future: EuPARXIA. This will be an European infrastructure for plasma acceleration development. In this paper, an overview of the research program of the Laboratory and of the future perspectives is presented.

Molybdenum Oxides Coatings for High Demanding Accelerator Components

Large electric gradients are required for a variety of new applications, notably including the extreme high brightness electron sources for X-ray free electron lasers (FELs), radio-frequency (RF) photo-injectors, industrial and medical accelerators, and linear accelerators for particle physics colliders. In the framework of the INFN-LNF, SLAC (USA), KEK (Japan), UCLA (Los Angeles) collaboration, the Frascati National Laboratories (LNF) are involved in the modelling, development, and testing of RF structures devoted to particles acceleration by high gradient electric fields of particles through metal devices. In order to improve the maximum sustainable gradients in normal-conducting RF-accelerating structures, both the RF breakdown and dark current should be minimized. To this purpose, studying new materials as well as manufacturing techniques are mandatory to identify better solutions to such extremely requested applications. In this contribution, we discuss the possibility of using a dedicated coating on a solid copper sample (and other metals) with a relatively thick film to improve and optimize breakdown performances and to minimize the dark current. We present here the first characterization of MoO3 films deposited on copper by pulsed-laser deposition (PLD).

Meaningful student involvement. Students as “researchers”: a physics laboratory experience from space to microworld

Teaching physics and technology is a challenging, rewarding and exciting arena where teachers share the fascinating concepts of physics and technology evolution in a room full of young and inquisitive minds. Every day teaching experience confirms that Science learning motivation is correlated to real world applications. According to the last PISA-OECD survey, the performance of Italian students in STEM is below the OECD average. In the last years the Italian Ministry of Education, University and Research (MIUR) has been active in promoting a wide plan to improve STEM learning. These actions strongly supported the connections and collaborations between high schools, universities and research centers. In this framework, the Frascati National Laboratories (LNF) play a very important role in science dissemination through a rich program of physics education activities addressed to Italian teachers and students from all the world. The main idea is that meaningful involvement of students can take the form of engaging students as researchers. In this article the LNF activities for schools are presented with a focus on a case study of a work-related learning program attended by seventeen students of the high school “Liceo Siciliani” from Catanzaro (Italy) in February/March 2017. The students had the possibility to participate in two different experiences related to particle physics and nanotechnology. The project concerning particle physics will have a follow up, since the school “Liceo Siciliani” proposed an experiment on cosmic rays that will take place in the Calabria region, based on the experimental setup the students studied and used at LNF.

The cylindrical-GEM inner tracker detector of the KLOE-2 experiment

The KLOE-2 experiment represents the continuation of KLOE. It acquired 5.5 fb−1 data from November 2014 to March 2018 with the aim of collecting the largest sample of ϕ mesons at the DAΦNE e+e− collider at Frascati National Laboratory of INFN.A new tracking device, the Inner Tracker, was installed at the interaction region of KLOE-2 and it was operated together with the Drift Chamber to improve track and vertex reconstruction capabilities of the new experimental apparatus. The Inner Tracker is a four-layer cylindrical triple-GEM detector with each layer equipped with an X-V strips-pads stereo readout. Although GEM detectors have been extensively used in high energy physics experiments, the IT, with its fully-cylindrical geometry is a frontier detector and KLOE-2 is the first experiment which benefited of this novel detector technology operated at a collider.The operation of the Inner Tracker will be presented, together with the results of the alignment and calibration and tracking–vertexing performance of such a unique detector.

The Investigation on the Dark Sector at the PADME Experiment

In this paper, we present the design and expected performance of the various detectors of the PADME experiment. The experiment design has been optimized for the detection of the final state photons produced along with a “Dark Photon”, decaying to invisible particles, in the annihilation a of 550 MeV positron with an atomic electron of a thin target. The PADME experiment has been built in a new dedicated experimental hall at the Beam Test Facility (BTF) of the INFN Frascati National Laboratories and has been taking data since the third quarter of 2018.

The calorimeters of the PADME experiment

Abstract The PADME experiment is under construction at the Frascati National Laboratories of INFN to explore the coupling between ordinary and dark matter. This will be done through the detection of Standard Model photons produced in the reaction e + e − → γ A ′ . The measurement of the photons 4-momentum allows to reconstruct the missing mass spectrum of this process, where the A ′ could appear as a peak. To this purpose, two independent electromagnetic calorimeters are used. The layout of the two detectors, and their expected performance measured during prototypes tests, are here presented.

Design and test of the Mu2e undoped CsI + SiPM crystal calorimeter

The Mu2e experiment at Fermilab will search for the charged-lepton flavour violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. The calorimeter plays an important role in providing a fast trigger filter, excellent particle identification and a seeding for track reconstruction. Its requirements are to provide an energy (timing) resolution better than 10% (0.5 ns) and a position resolution below 1 cm, for 100 MeV electrons. The calorimeter consists of two disks, each one made of 674 un-doped CsI crystals readout by two large area arrays of 2 × 3 UV-extended SiPMs of 6 × 6 mm^2 dimensions. A large scale prototype (Module-0) has been constructed and tested with an electron beam in the energy range between 60 and 120 MeV at the BTF of Frascati National Laboratories. Results demonstrated that this calorimeter satisfies the Mu2e requirements.

Proposal for Using DAΦNE as Pulse Stretcher for the Linac Positron Beam

The PADME experiment [1] aims at searching for the dark photon (A’) in the e+e− → Aγ′ process in a positron-on-target experiment, exploiting the positron beam of the DAΦNE Linac at the INFN Frascati National Laboratory (Italy). The Linac can provide a number of positrons in excess of 1010 in a 200 ns long pulse but, in order to keep the pile-up probability in the calorimeter at an acceptable level, the number of positrons for PADME has to be below 105/pulse, in particular by using the attenuating target in the BTF beam-line. The experiment is then essentially limited by the low duty factor (10−5 = 200 ns/20 ms). In this paper, an alternative proposal to use the DAΦNE positron ring as a Linac pulse stretcher, by injecting each pulse into the ring and extracting it by a slow resonant extraction using the m/3 resonance, is presented. This would allow for distributing the positrons of a single Linac pulse over a much longer time interval (0.2-0.5 ms), increasing the duty factor up to ∼1%. The required modifications of the DAΦNE positron transfer line and ring are described. A dedicated lattice for the positron ring has been designed and tracking of the positrons injected in the ring has been performed in order to optimize the extraction parameters and to give a preliminary estimate of the extracted beam characteristics.

Polycapillary based μXRF station for 3D colour tomography

The “Rainbow X-Ray” (RXR) experimental station at XLab Frascati of the Frascati's National Laboratories (LNF) INFN is a dedicated station for X-ray fluorescence studies based on the use of polycapillary lenses in a confocal geometry. The flexible RXR layout allows investigating specimens of the dimensions ranging from several millimeters up to half meter and weighting up to several tens of kilograms. Compared to similar existing XRF stations, apart of the possibility for investigating large samples, the main advantage of this equipment is the detection system with two spectrometers optimized to work separately at high and at low X-ray energies. The confocal geometry combined with a 3-axes fine motion system makes possible 3D μXRF elemental tomographic acquisitions (colour tomography). At present this station in operation at high XRF energies is used for cultural heritage and geological applications. We present and discuss here the analytical performances of this experimental station pointing out the advantages in different application areas.

The PADME calorimeters for missing mass dark photon searches

In this paper we will present the design and expected performance for the Electromagnetic and Small Angle Calorimeters (ECAL, SAC) of the PADME experiment. The design of the calorimeters has been optimized for the detection of the final state γ from the annihilation production (and subsequent “invisible” decay) of a “Dark Photon” produced by a positron beam on a thin, low Z target. Beam tests have been made in 2016 and 2017 at the INFN Frascati National Laboratories Linac Beam Test Facility (BTF) with positron beams of energy 100–400 MeV and results are presented. The PADME experiment will be built at the INFN Frascati National Laboratories by the end of 2017 and will be taking data in 2018 (and possibly also 2019). At the moment the collaboration is composed by the following institutions: INFN Roma and “La Sapienza” University of Roma, INFN Frascati, INFN Lecce and University of Salento, MTA Atomki Debrecen, University of Sofia, Cornell University, U.S. William and Mary College.

Status of the KLOE-2 experiment

The KLOE-2 experiment is steadily taking data since November 2014 at DAFNE, the Φ-factory in the Frascati National Laboratories. 3.5 fb−1 of integrated luminosity have been collected up to now, with an average rate of 10 pb−1/day. Performance of the detector, data taking conditions and data quality monitoring are briefly summarized.

Status of the KLOE-2 experiment at the Frascati National Laboratory of INFN

The KLOE-2 experiment is steadily taking data since November 2014 at DAΦNE, the ϕ-factory in the Frascati National Laboratories. An integrated luminosity of 3.5 fb−1 has been collected up to now, with an average rate of 10 pb−1/day. Performances of the detector, data taking conditions, data quality monitoring and physics perspectives will be discussed.

The cylindrical GEM detector of the KLOE-2 experiment

The KLOE-2 experiment started its data taking campaign in November 2014 with an upgraded tracking system at the DAΦNE electron-positron collider at the Frascati National Laboratory of INFN. The new tracking device, the Inner Tracker, operated together with the KLOE-2 Drift Chamber, has been installed to improve track and vertex reconstruction capabilities of the experimental apparatus. The Inner Tracker is a cylindrical GEM detector composed of four cylindrical triple-GEM detectors, each provided with an X-V strips-pads stereo readout. Although GEM detectors are already used in high energy physics experiments, this device is considered a frontier detector due to its fully-cylindrical geometry: KLOE-2 is the first experiment benefiting of this novel detector technology. Alignment and calibration of this detector will be presented together with its operating performance and reconstruction capabilities.