A particle traversing a crystal aligned with one of its crystallographic axes experiences a strong electromagnetic field that is constant along the direction of motion over macroscopic distances. For and γ -rays with energies above a few GeV , this field is amplified by the Lorentz boost, to the point of exceeding the Schwinger critical field ℰ_0 ∼ 1.32 × 10^16 V/cm . In this regime, nonlinear quantum-electrodynamical effects occur, such as the enhancement of intense electromagnetic radiation emission and pair production, so that the electromagnetic shower development is accelerated and the effective shower length is reduced compared to amorphous materials. We have investigated this phenomenon in lead tungstate ( PbWO_4 ), a high-Z scintillator widely used in particle detection. We have observed a substantial increase in scintillation light at small incidence angles with respect to the main lattice axes. Measurements with 120 GeV electrons and γ -rays between 5 and 100 GeV demonstrate up to a threefold increase in energy deposition in oriented samples. These findings challenge the current models of shower development in crystal scintillators and could guide the development of next-generation accelerator- and space-borne detectors.

The Spin Physics Detector collaboration proposes to install a universal detector in the second interaction point of the NICA collider under construction (JINR, Dubna) to study the spin structure of the proton and deuteron and other spin-related phenomena using a unique possibility to operate with polarized proton and deuteron beams at a collision energy up to 27 GeV and a luminosity up to 10^32 cm^-2 s^-1. As the main goal, the experiment aims to provide access to the gluon TMD PDFs in the proton and deuteron, as well as the gluon transversity distribution and tensor PDFs in the deuteron, via the measurement of specific single and double spin asymmetries using different complementary probes such as charmonia, open charm, and prompt photon production processes. Other polarized and unpolarized physics is possible, especially at the first stage of NICA operation with reduced luminosity and collision energy of the proton and ion beams. This document is dedicated exclusively to technical issues of the SPD setup construction.

Electromagnetic calorimeters used in high-energy physics and astrophysics rely heavily on high-Z inorganic scintillators, such as lead tungstate (PbWO4 or PWO). The crystalline structure and lattice orientation of inorganic scintillators are frequently underestimated in detector design, even though it is known that the crystalline lattice strongly modifies the features of the electromagnetic processes inside the crystal. A novel method has been developed for precisely bonding PWO crystals with aligned atomic planes within 100 μrad, exploiting X-ray diffraction (XRD) to accurately measure miscut angles. This method demonstrates the possibility to align a layer of crystals along the same crystallographic direction, opening a new technological path towards the development of next-generation electromagnetic calorimeters.

Progress in experimental high-energy physics has been closely tied to developments of high-performance calorimeters. Since their invention, crystal calorimeters have consistently achieved the best resolution for measurements of the energies of electromagnetic (e.m.) particles (electrons and photons). Recently, we experimentally demonstrated the possibility of significantly accelerating the e.m. shower development inside lead tungstate (PWO) crystal when the incident beam is aligned with the crystal axes within some tenths of a degree. Here, we present the innovative photodetection system, based on Silicon PhotoMultipliers, implemented for the direct measurement of the scintillation light enhancement in case of beam aligned to the main crystal axes, along with its characterization performed with cosmic rays at the Insulab laboratory (Insubria University, Como). In 2021 we performed a test at H2 beam line of CERN SPS with a hundred-GeV electron beam with two PWO samples (1 and 2 X0 thick) directly coupled with SiPMs. Since the angular acceptance of the crystal strong field depends weakly on particle energy, while instead the decreasing of the shower length remains pronounced at very high-energy, a crystal calorimeter based on oriented crystals would feature a consistent compactness enhancement while rivaling the current state of the art in terms of resolution in the range of interest of present and future forward detectors, beam dumps for light dark matter search and source-pointing space-borne γ-ray telescopes.

. - Recently, the particle physics community has put an increasing effort in developing radiation detectors and equipment based on oriented crystals. A key feature that distinguishes an oriented crystal from the ordinary matter is the reduc-tion of the radiation length (X0) seen by electrons, positrons and photons crossing the lattice along one of its symmetry axes. This effect has been experimentally ob-served only in the last few decades and with samples limited in number, composition and length. In order to characterize a variety of oriented crystals with a standardized procedure, the STORM Collaboration has developed an advanced modular setup, which allows to study the features of any crystal sample with both electron (or positron) and photon beams. This contribution describes the key elements of this setup, namely silicon strip tracking detectors, plastic scintillators, Silicon Photo -Multipliers (SiPMs) coupled to the crystal under test, a photon calorimeter and an electromagnetic spectrometer.

Progress in high-energy physics has been closely tied to the development of high-performance electromagnetic calorimeters. Recent experiments have demonstrated the possibility to significantly accelerate the development of electromagnetic showers inside scintillating crystals typically used in homogeneous calorimeters based on scintillating crystals when the incident beam is aligned with a crystallographic axis to within a few mrad. In particular, a reduction of the radiation length has been measured when ultrarelativistic electron and photon beams were incident on a high- Z scintillator crystal along one of its main axes. Here, we propose the possibility to exploit this physical effect for the design of a new type of compact e.m. calorimeter, based on oriented ultra-fast lead tungstate (PWO-UF) crystals, with a significant reduction in the depth needed to contain electromagnetic showers produced by high-energy particles with respect to the state-of-the-art. We report results from tests of the crystallographic quality of PWO-UF samples via high-resolution X-ray diffraction and photoelastic analysis. We then describe a proof-of-concept calorimeter geometry defined with a Geant4 model including the shower development in oriented crystals. Finally, we discuss the experimental techniques needed for the realization of a matrix of scintillator crystals oriented along a specific crystallographic direction. Since the angular acceptance for e.m. shower acceleration depends little on the particle energy, while the decrease of the shower length remains pronounced at very high energy, an oriented crystal calorimeter will open the way for applications at the maximum energies achievable in current and future experiments. Such applications span from forward calorimeters, to compact beam dumps for the search for light dark matter, to source-pointing space-borne γ -ray telescopes, to decrease the size and the cost of the calorimeter needed to fully contain e.m. showers initiated by GeV to TeV particles.

We have observed a significant enhancement in the energy deposition by 25– 100 GeV photons in a 1 cm thick tungsten crystal oriented along its ⟨ 111 ⟩ lattice axes. At 100 GeV , this enhancement, with respect to the value observed without axial alignment, is more than twofold. This effect, together with the measured huge increase in secondary particle generation is ascribed to the acceleration of the electromagnetic shower development by the strong axial electric field. The experimental results have been critically compared with a newly developed Monte Carlo adapted for use with crystals of multi- X_0 thickness. The results presented in this paper may prove to be of significant interest for the development of high-performance photon absorbers and highly compact electromagnetic calorimeters and beam dumps for use at the energy and intensity frontiers.

a scintillating crystal can influence the development of the electromagnetic processes inside it. For electron and photon beams aligned with the symmetry axis of a crystal, if the Strong Field condition is satisfied, a reduction of the radiation length (X 0 ) is expected. However, these effects have been experimentally observed only in the last few years, with crystal samples limited in number, composition and length. The lack of experimental data for these phenomena makes it harder to properly account for them in the design and simulation of innovative radiation detectors and equipment, such as active beam dumps or compact electromagnetic calorimeters. Recent experiments, performed by the STORM and KLEVER collaborations at the CERN SPS extracted beam lines, demonstrated a significant reduction of X 0 for photon beams impinging on a crystal within ∼ 0 . 1 ◦ from one of its symmetry axes. This contribution will describe such experiments, reporting preliminary results for a 2 X 0 PbF 2 crystal and a 1 X 0 PbWO 4 crystal. 2 sample: the high-energy tail grows by a factor 10 ÷ 50, while the average PH by a factor ≈ 1 . 35. Similar results are observed for incidence angles ≤ 1 Θ 0 , where Θ 0 ≈ 1 mrad is the expected angular range of the SF regime. At 4 Θ 0 the enhancement effect is seen to be still evident, even if somewhat less significant. Similar results have been obtained also for the PbWO 4 sample: the high-energy tail of the spectrum grows by a factor 10 ÷ 70, while the average PH is enhanced by a factor ≈ 1 . 55. These results already suggest that the radiation length of the two materials is reduced by ≈ ( 20 ÷ 30 ) %; a more accurate estimate of this reduction will be soon given by directly studying how the energy deposited in the crystal, measured by the SiPMs, changes as a function of the beam-crystal alignment.

The Spin Physics Detector, a universal facility for studying the nucleon spin structure and other spin-related phenomena with polarized proton and deuteron beams, is proposed to be placed in one of the two interaction points of the NICA collider that is under construction at the Joint Institute for Nuclear Research (Dubna, Russia). At the heart of the project there is huge experience with polarized beams at JINR. The main objective of the proposed experiment is the comprehensive study of the unpolarized and polarized gluon content of the nucleon. Spin measurements at the Spin Physics Detector at the NICA collider have bright perspectives to make a unique contribution and challenge our understanding of the spin structure of the nucleon. In this document the Conceptual Design of the Spin Physics Detector is presented.

In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and adding novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100TeV. Its unprecedented centre of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries.

We announce a proposal for collaboration, intended to build the antineutrino detector under the Belarus Nuclear Power Plant. Here we discuss the reactor antineutrino spectra, the reactions to detect neutrino, possible design and location of detector.

Рассмотрены результаты измерений энергетического разрешения перспективного сцинтилляционного кристалла Се : GAGG, выращенного в Научно-исследовательском институте ядерных проблем Белорусского государственного университета. Исследования проводились в диапазоне энергий регистрируемых гамма-квантов от 20 кэВ до 3 МэВ. Изучался образец прямоугольной формы размером 12 × 12 × 9 мм. В качестве фотоприемников использовались фотоумножители Hamamatsu R3998-100-02, лавинный фотодиод S8664-1010 и кремниевые матрицы (SiPM) производства фирмы SensL. Энергетическое разрешение на линии 137 Cs (662 кэВ) составило порядка 7,5 %, что не уступает разрешению широко используемых сцинтилляторов NaI(Tl), CsI(Tl) аналогичного размера. С учетом того что кристаллы Се : GAGG не гигроскопичны и по сравнению с NaI(Tl), CsI(Tl) характеризуются существенно более коротким временем высвечивания (~ 80 нс) и более высокой эффективностью, они представляются весьма перспективными для использования в гамма-спектрометрах и в качестве позиционно-разрешаемых элементов пространственно-чувствительных детекторов энергичных частиц и гамма-квантов.

3D printing of electronics is very prospective technology, so it has strong demand for the research and application. Nowadays 3D printing can be applied from rapid prototyping using simple and inexpensive table-top commercially available 3D printers to the low-cost 3D fabrication of functional electronic circuits combining printed and mounted components. Implementation of the 3D printing technologies to electronics depends on a material printability, its electric properties and mechanical stability. Extensive research devoted to the development of the printable materials with new functionality, e.g. nanocomposites. Nanocomposites based on polymer binders filled with structured carbon nano-objects showed, for example, good prospects as electromagnetic screens in microwave and infrared spectral regions. 3D printing technology can produce from these materials complicated supports and housings of various shapes providing charge transfer and electromagnetic shielding. Development of 3D structures made of conductive polymers requires exact modeling of their electric and electromagnetic properties. In this article we describe 3D printing technology with thermoplastics including carbon nanocomposites and share an example of 3D conductive lattice modeling.

Nanocomposites, i.e., polymer composites filled with conductive nano-fillers have been shown to be promising materials as broadband microwave absorbers. However, increasing the filler content above a critical value cannot provide further improvements of nanocomposite electromagnetic properties. Herein, the electromagnetic interference shielding efficiency of gamma-irradiated polymer composites was investigated. For that purpose, nine types of nanocomposites based on various polymers and various nanocarbon fillers were prepared and treated with gamma irradiation from Co-60 source by cumulative absorption doses up to 750 kGy. The corresponding electromagnetic properties (reflection, transmission, and absorption) were then measured in the K-a microwave frequency range. The experiments revealed two distinct behaviors, depending on the polymer matrix and the filler: either an improvement of the electromagnetic response under gamma-irradiation of about 90 kGy, or a high tolerance to irradiation up to 750 kGy.

A prototype of a 2D detector based on specially designed straw tubes with cathode data readout has been developed and tested. This detector exhibits comparable accuracies in measuring radial and longitudinal coordinates. Its rate capability is similar to the capabilities of traditional detectors whose tubes are smaller by half in diameter.

Crystalline collimators can potentially considerably improve the cleaning performance of the presently used collimator systems using amorphous collimators. A crystal-based collimation scheme which relies on the channeling particle deflection in bent crystals has been proposed and extensively studied both theoretically and experimentally. However, since the efficiency of particle capture into the channeling regime does not exceed ninety percent, this collimation scheme partly suffers from the same leakage problems as the schemes using amorphous collimators. To improve further the cleaning efficiency of the crystal-based collimation system to meet the requirements of the FCC, we suggest here a double crystal-based collimation scheme, to which the second crystal is introduced to enhance the deflection of the particles escaping the capture to the channeling regime in its first crystal. The application of the effect of multiple volume reflection in one bent crystal and of the same in a sequence of crystals is simulated and compared for different crystal numbers and materials at the energy of 50 TeV. To enhance also the efficiency of use of the first crystal of the suggested double crystal-based scheme, we propose: the method of increase of the probability of particle capture into the channeling regime at the first crystal passage by means of fabrication of a crystal cut and the method of the amplification of nonchanneled particle deflection through the multiple volume reflection in one bent crystal, accompanying the particle channeling by a skew plane. We simulate both of these methods for the 50 TeV FCC energy.

The development of high-energy electromagnetic showers in long oriented lead tungstate crystals, accelerated by the effects induced by the strong field of atomic strings, is simulated for the first time. For that the characteristics of pair production and gamma-radiation by electrons or positrons were first simulated by the direct application of Baier-Katkov formulae in a thin PWO crystal to derive the scaling coefficients of the corresponding Bethe-Heitler cross sections to be incorporated into GEANT4 for the simulation of the electromagnetic shower development in a long crystal. Simulation results demonstrate the significant influence of the crystal structure on the e± and gamma-quanta registration processes in the existing homogeneous electromagnetic calorimeters and gamma-telescopes as well as wide possibilities of improving their performance in future developments.

Precise measurement of straw axial coordinate (along the anode wire) with accuracy compatible with straw radial coordinate determination by drift time measurement and increase of straw detector rate capability by using straw cathode readout instead of anode readout are presented.