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The measurements of lifetimes and electromagnetic moments of the isomeric states in some of the nuclei around A ≈ 135 carried out at BARC-TIFR Pelletron Linac Facility at TIFR, Mumbai, are highlighted. The results from these measurements, along with similar studies reported in the literature, provide a wealth of nuclear structure information in Ba, La, and Ce isotopes in the A ≈ 135 region. Comparison of the measured moments with the calculations gives a unique testing ground for the predictive power of the nuclear models. Plans for similar studies in other mass regions are also described at the end. [ABSTRACT FROM AUTHOR]

Alternating current magnetic flux leakage (ACMFU technology has been used for sizing pipeline cracks. However, traditional ACMFL methods are limited in sensitively identifying arbitrary angles of pipeline cracks due to the complexity of crack morphology. To solve the problem, a multi-frequency balanced electromagnetic field measurement (MF-BEFM) method is proposed. First the distortion of the magnetic field and eddy current field caused by crack defects was studied. Then, the effects of the excitation frequency on balanced electromagnetic field measurement (BEFM) signals were considered to select optimal parameters. Next, the relationship between the BEFM signal and crack angle was studied. Finally, the MF-BERM experiment was conducted to prove the superiority of the proposed method. The results show that the BEFM method cannot only overcome the deficiency of directional detection of ACMFL methods but it call also achieve high detection sensitivity for identifying arbitrary angles of cracks on the pipeline surface. [ABSTRACT FROM AUTHOR]

This study presents the measurements of exposure to electromagnetic fields, carried out comparatively following standard methods from fixed sites using a broadband meter and using a smartphone on which an App designed for this purpose has been installed. The results of two measurement campaigns carried out on the campus of the University of Alcalá over an area of 1.9 km2 are presented. To characterize the exposure, 20 fixed points were measured in the first case and 860 points along the route made with a bicycle in the last case. The results obtained indicate that there is proportionality between the two methods, making it possible to use the smartphone for comparative measurements. The presented methodology makes it possible to characterize the exposure in the area under study in four times less time than that required with the traditional methodology. [ABSTRACT FROM AUTHOR]

Fluorescent nanodiamonds (FNDs) containing quantum defects enable the optical measurement of electromagnetic fields and temperature and are among the most developed nanoscale quantum sensors today. Yet, for many applications in biomedicine and beyond, FNDs must be integrated into biocompatible substrates that preserve FND sensitivity and bring FNDs within nanoscale distance of their sensing target. At the same time, the high excitation light intensity required for most quantum sensing protocols remains a major challenge for applications in biomedicine. Here, it is shown that FNDs embedded in polyvinyl‐alcohol (PVA) fibers are a powerful 3D platform for nanoscale quantum sensing via light guiding. First, it is demonstrated that biocompatible PVA fibers can guide light to excite FNDs >10 µm from the excitation beam. Using this light‐guiding‐enabled excitation, optically detected magnetic resonance (ODMR) and T1 spin relaxometry measurements are performed using the nitrogen‐vacancy (NV) center in FNDs. Through ODMR thermometry, it is shown that light‐guiding‐enabled excitation mitigates light‐induced heating. Finally, the quantum sensing capability of the platform is established by detecting paramagnetic gadolinium in a dry and aqueous environment using T1 relaxometry of the NV center in FNDs. These results pave the way for light‐guiding‐enabled optical quantum sensing in biomedicine using nanodiamond‐doped biosubstrates. [ABSTRACT FROM AUTHOR]

We consider a general case of a magnetotelluric (MT) study to reveal three-dimensional (3D) distribution of the electrical conductivity within the Earth based on measurements of electromagnetic (EM) fields by a two-dimensional (2D) array. Such an MT array observation can be regarded as a spatially discrete sampling of the MT responses (impedances), and each observation site can be regarded as a sampling point. This means that MT array measurements must follow the Nyquist–Shannon sampling theorem. This paper discusses how the sampling theorem is applied to MT array studies and what kind of consideration is required in the application on the basis of synthetic model calculations, with special attention to spatial resolutions. With an aid of the EM scattering theory and the sampling theorem, we can show that an observation array resolves some features of the MT impedance but does not others. We call the resolvable and unresolvable features the MT signal and noise, respectively. This study introduces the spatial Fourier transform of array MT data (impedances) which helps us investigating sampling effects of lateral heterogeneity from a different angle (in the wavenumber domain). Shallow heterogeneities cause a sharp spatial change of impedance elements near structural boundaries. High wavenumber Fourier components are required to describe such a feature, which means the site spacing must be sufficiently short to be able to resolve such features. Otherwise, a set of array MT data will suffer from aliasing, which is one of the typical causes of MT distortion (MT geologic noise). Conversely, a signal due to a deep-seated conductivity anomaly will have more reduced amplitude at higher wavenumbers, which means focused imaging of such an anomaly is generally difficult. Finally, it is suggested to properly consider the sampling theorem in an observation array design, so as to have best performance in resolving MT signals. [ABSTRACT FROM AUTHOR]

Radiated electromagnetic emission of photovoltaic systems, for example, adversely impacting radiocommunication, can pose a major barrier against further increase in photovoltaic penetration. This is particularly the case near sensitive infrastructure and activities such as hospitals, airports, search and rescue, and military. To understand the impact of each component and installation detail, we performed systematic radiated electromagnetic emission measurements on comparable commercial photovoltaic systems in the frequency range 150 kHz to 30 MHz. Our measurements indicate that string inverters are unlikely to interfere with radiocommunication when installed according to recommended standards, rules, guidelines, and regulations. It was shown that module-level power optimizers are the main cause of high levels of radiated emissions. The frameless bifacial module showed higher levels of radiated emissions than the monofacial module with frame. Changes in cable management and earthing have less impact on radiated emissions than the choice of solar inverter concept and module type. [ABSTRACT FROM AUTHOR]

This paper presents a groundbreaking Ku-band 20W RF front-end power amplifier (PA), designed to address numerous challenges encountered by satellite communication systems, including those pertaining to stability, linearity, cost, and size. The manuscript commences with an exhaustive discussion of system design and operational principles, emphasizing the intricacies of low-noise amplification, and incorporating key considerations such as noise factors, stability analysis, gain, and gain flatness. Subsequently, an in-depth study is conducted on various components of the RF chain, including the pre-amplification module, driver-amplification module, and final-stage amplification module. The holistic design extends to the inclusion of the display and control unit, featuring the power-control module, monitoring module, and overall layout design of the PA. It is meticulously tailored to meet the specific demands of satellite communication. Following this, a thorough exploration of electromagnetic simulation and measurement results ensues, providing validation for the precision and reliability of the proposed design. Finally, the feasibility of that design is substantiated through systematic system design, prototype production, and exhaustive experimental testing. It is noteworthy that, in the space-simulation environmental test, emphasis is placed on the excellent performance of the Star Ku-band PA within the 13.75GHz to 14.5GHz frequency range. Detailed power scan measurements reveal a P1dB of 43dBm, maintaining output power flatness < ± 0.5dBm across the entire frequency and temperature spectrum. Third-order intermodulation scan measurements indicate a third-order intermodulation of ≤ -23dBc. Detailed results of power monitoring demonstrate a range from +18dBm to +54dBm. Scans of spurious suppression and harmonic suppression, meanwhile, show that the PA evinces spurious suppression ≤ -65dBc and harmonic suppression ≤ -60dBc. Rigorous phase-scan measurements exhibit a phase-shift adjustment range of 0° to 360°, with a step of 5.625°, and a phase-shift accuracy of 0.5dB. Detailed data from gain-scan measurements show a gain-adjustment range of 0dB to 30dB, with a gain flatness of ± 0.5dB. Attenuation error is ≤ 1%. These test parameters perfectly align with the practical application requirements of the technical specifications. When compared to existing Ku-band PAs, our design reflects a deeper consideration of specific requirements in satellite communication, ensuring its outstanding performance and uniqueness. This PA features good stability, high linearity, low cost, and compact modularity, ensuring continuous and stable power output. These features position the proposed system as a leader within the market. Successful orbital deployment not only validates its operational stability; it also makes a significant contribution to the advancement of China's satellite PA technology, generating positive socio-economic benefits. [ABSTRACT FROM AUTHOR]

Conventional techniques that measure the concentration of light elements in metallic materials lack high-resolution performance due to their intrinsic limitation of sensitivity. In that context, scanning microwave microscopy has the potential to significantly enhance the quantification of element distribution due to its ability to perform a tomographic investigation of the sample. Scanning microwave microscopy associates the local electromagnetic measurement and the nanoscale resolution of an atomic force microscope. This technique allows the simultaneous characterization of oxygen concentration as well as local mechanical properties by microwave phase shift and amplitude signal, respectively. The technique was calibrated by comparison with nuclear reaction analysis and nanoindentation measurement. We demonstrated the reliability of the scanning microwave technique by studying thin oxygen-enriched layers on a Ti-6Al-4V alloy. This innovative approach opens novel possibilities for the indirect quantification of light chemical element diffusion in metallic materials. This technique is applicable to the control and optimization of industrial processes. [ABSTRACT FROM AUTHOR]

The geometric properties of the pore space govern the electrical and hydraulic properties of soils. Recognizing this commonality, this paper proposes a new approach to determine permeability from high-frequency electromagnetic (HF–EM) measurements on geomaterials undergoing evaporative dewatering. Two materials have been used; (1) kaolin, a reference geomaterial; and (2) a dredged sediment sample from the Port of Brisbane (PoB) reclamation site (Queensland, Australia). Based on a dielectric mixture equation that integrates Archie's parameters, the evolution of formation factors as a functions of porosity have been derived. Several models that are available in the literature have been used to estimate proxies for geometric length scales for pore radii. With knowledge of the formation factors and proxies for pore radii as functions of porosity, permeabilities of the materials under saturated conditions have been estimated. The results have been compared with experimentally obtained permeabilities. Using the formation factors from HF–EM measurements and two of the proxies for pore radii (hydraulic and characteristic pore radii, as defined in this paper), a good degree of agreement with the experimental data has been obtained within a variation in one-order of magnitude for kaolin. For the PoB material, the use of hydraulic pore radius yielded the best estimation of permeability. [ABSTRACT FROM AUTHOR]

Subsurface energy resources are often found in three‐dimensional and non‐spatially continuous rock formations that exhibit electrical anisotropy. Deep‐sensing tri‐axial borehole electromagnetic measurements are currently being used to detect three‐dimensional fluid‐bearing subsurface formations, but borehole environmental, geometrical and instrument‐design factors, together with measurement noise, constrain their practical range of detection and spatial resolution. By understanding the interplay of the above factors on the detectability and sensitivity of borehole deep electromagnetic measurements, one can potentially quantify the uncertainty of both target spatial location (relative to the well trajectory) and electrical resistivity contrast, thereby improving the certainty of three‐dimensional well navigation in real time. We implement a finite‐volume method to numerically solve Maxwell's equations for three‐dimensional electrically anisotropic heterogeneous rock formations in the calculation of magnetic fields measured with deep‐sensing tri‐axial borehole electromagnetic instruments. The calculated magnetic fields at measurement locations are described as the per cent difference between measurements acquired in rock formations with and without conductive or resistive three‐dimensional targets. We quantify the maximum radial distance of detection from the well trajectory and the spatial sensitivity of a commercially available deep‐sensing electromagnetic instrument with respect to environmental factors and measurement acquisition parameters by assuming that the borehole electromagnetic instrument can reliably detect offset three‐dimensional targets if the corresponding per cent measurement difference exceeds the threshold for measurement noise. Results indicate that commercially available tri‐axial deep‐sensing borehole electromagnetic instruments can achieve maximum detection distances between a quarter of and a full transmitter–receiver spacing. In addition, we show that radial detection distances vary from 0.3 to 2 skin depths depending on the geological environment, that is, target conductivity contrast with respect to the embedding background, electrical anisotropy of the background formation and targets and measurement acquisition parameters, that is, frequency and transmitter–receiver spacings. The above findings are not only important for instrument design and measurement‐acquisition planning but also for the effective implementation of real‐time inversion‐based measurement interpretation procedures. [ABSTRACT FROM AUTHOR]

The current and next observation seasons will detect hundreds of gravitational waves (GWs) from compact binary systems coalescence at cosmological distances. When combined with independent electromagnetic measurements, the source redshift will be known, and we will be able to obtain precise measurements of the Hubble constant H 0 via the distance–redshift relation. However, most observed mergers are not expected to have electromagnetic counterparts, which prevents a direct redshift measurement. In this scenario, one possibility is to use the dark sirens method that statistically marginalizes over all the potential host galaxies within the GW location volume to provide a probabilistic source redshift. Here we presented H 0 measurements using two new dark sirens compared to previous analyses using DECam data: GW190924 |$\_$| 021846 and GW200202 |$\_$| 154313. The photometric redshifts of the possible host galaxies of these two events are acquired from the DECam Local Volume Exploration Survey (DELVE) carried out on the Blanco telescope at Cerro Tololo. The combination of the H 0 posterior from GW190924 |$\_$| 021846 and GW200202 |$\_$| 154313 together with the bright siren GW170817 leads to |$H_{0} = 68.84^{+15.51}_{-7.74}\, \rm {km\, s^{-1}\, Mpc^{-1}}$|⁠. Including these two dark sirens improves the 68  per cent confidence interval (CI) by 7  per cent over GW170817 alone. This demonstrates that the addition of well-localized dark sirens in such analysis improves the precision of cosmological measurements. Using a sample containing 10 well-localized dark sirens observed during the third LIGO/Virgo observation run, without the inclusion of GW170817, we determine a measurement of |$H_{0} = 76.00^{+17.64}_{-13.45}\, \rm {km\, s^{-1}\, Mpc^{-1}}$|⁠. [ABSTRACT FROM AUTHOR]

Electromagnetic (EM) composites have stimulated tremendous fundamental and practical interests owing to their flexible electromagnetic properties and extensive potential engineering applications. Hence, it is necessary to systematically understand the physical mechanisms and design principles controlling EM composites. In this Tutorial, we first provide an overview of the basic theory of electromagnetism about electromagnetic constitutive parameters that can represent the electromagnetic properties of materials. We show how this corpus allows a consistent construction of effective medium theories and allows for numerical simulation of EM composites to deal with structure–property relationships. We then discuss the influence of spatial dispersion of shaped inclusions in the material medium on the EM properties of composites, which has not been systematically illustrated in the context of this interdisciplinary topic. Next, artificial composites or metamaterials with peculiar properties not readily available in nature are highlighted with particular emphasis on the control of the EM interaction with composites. We conclude by discussing appropriate methods of electromagnetic measurement and practical aspects for implementing composites for specific applications are described. Overall, this Tutorial will serve the purpose of introducing the basics and applications of electromagnetic composites to newcomers in this field. It is also anticipated that researchers from different backgrounds including materials science, optics, and electrical engineering can communicate to each other with the same language when dealing with this interdisciplinary subject and further push forward this advancement from fundamental science to technological applications. [ABSTRACT FROM AUTHOR]

The presence and importance of small drones (unmanned aerial vehicles) are increasing. With traditional radar detection the target radar cross section and its statistical properties are needed in order to design the detector and to assess detection performance. The authors make a statistical analysis of the radar cross section of two small fixed‐wing drones using measured data from typical flights. Using data from a typical flight instead of measurements or electromagnetic calculations as a function of aspect angle is a convenient method. Work results of the authors in mean values, medians and standard deviations, in analyses of common target probability distributions and in decorrelation times for the radar cross section, are necessary for design and assessment of the detection performance. The authors suggest a new target probability distribution which agrees better with the measured data than the others tested. The authors also note significant differences between the drones. [ABSTRACT FROM AUTHOR]

This paper proposes a nondestructive, separate transmitter-receiver (TX-RX) electromagnetic measurement system for near-surface detection. Different from the traditional dual-coil integrated design, the proposed transient electromagnetic (TEM) system performs shallow subsurface detection using independent TX coil and movable RX coils. This configuration requires a large primary field so that the far-away secondary field is able to generate reliably induced voltages. To achieve this goal, a bipolar current-pulsed power supply (BCPPS) with a late resonant charging strategy is designed to produce a sufficiently large magnetic moment for the exciting coil with low source interference. The magnetic dipole source (MDS) with a large proportion of weight is separated from the field observation device and does not need to be dragged or transported during the detection process. This setup lowers the weight of the scanning device to 3 kg and greatly improves the measurement efficiency. The results of the laboratory test verify the effectiveness of the separate MDS and RX module system. Field experimental detection further demonstrates that the proposed system can realize highly efficient and shallow surface detection within a 200 m range of the MDS device. [ABSTRACT FROM AUTHOR]

Detection of induced polarization (IP) effects in airborne electromagnetic measurements does not yet have an established methodology. This work contributes a Bayesian approach to the IP detectability problem using decoupled transdimensional layered models and applies an approach novel to geophysics whereby transdimensional proposals are used within the embarrassingly parallelizable and robust sequential Monte Carlo class of algorithms for the simultaneous inference of parameters and models. This algorithm allows for adaptivity considerations for multiple models and proposal types. Methodological contributions to solid Earth geophysics include the decoupled layered model approach and proposal of a statistic that uses posterior model odds for IP detectability. A case study is included investigating the detectability of IP effects in airborne electromagnetic data at a broad scale. [ABSTRACT FROM AUTHOR]

The technological development in measuring devices is massive due to the need for accurate flow measurements in various industries. However, the problem is choice of the flow meter for the complex and harsh environmental industrial applications. Due to the varied characteristic of gas and liquids, the mass flow meter provides an inaccurate result. Hence, this paper introduces the advancements in volumetric flow meters that provide highly accurate flow measurements. The various volumetric flow meter investigated in the paper are used for measurement of liquid, gas, and multi-phase flow. The study shows that electromagnetic is more suitable for complex environments of chemical and petroleum industries. The ultrasonic flow meter is a better alternative than the electromagnetic meter when the price is not a major concern. The ultrasonic flow meter also provides higher accuracy than other measurement techniques in multiple-phase-flow condition. However, electromagnetic measurements are only suitable for conducting liquids. [ABSTRACT FROM AUTHOR]

Direct contact, frequency-dependent, electrical relaxation effects in soils are well documented in both conductivity and dielectric permittivity-dominated frequency regimes. These relaxation signatures result from charge displacement in physical processes at varying scales ranging from conductivity-dominated ionic transport at soil–grain pore-fluid interfaces to permittivity-dominated water molecule rotation. Given the physical mechanisms associated with these relaxation signatures, it is possible to gain vital soil characteristics needed for a variety of civil and environmental applications. Yet, at the field scale, these direct contact geophysical methods are generally time-consuming and cumbersome hindering the extent at which data can be reasonably acquired. Here, we evaluate a standoff high-frequency electromagnetic induction (HFEMI) instrument, designed for remote, non-contact detection of non-metallic unexploded ordinance and repurposed as a means to measure soil relaxation effects remotely. The instrument offers a proven interrogation range of 100 kHz–10 MHz but has the ability to record data as low as 100 Hz. In this laboratory study, we demonstrate the effects of sample volume using NaCl solutions, where greater volume samples are necessary to overcome low signal-to-noise signatures. Further, pyrite, a mineral known to exhibit relaxation signatures at low frequencies was used in sand mixtures of varying concentrations and varying pore-fluid conductivity to explore the lower frequency range of the HFEMI instrument. The resulting measured HFEMI responses demonstrated sensitivity to the changes in conductivity due to increased pyrite and pore-fluid NaCl concentrations at high frequencies, but the lower frequency range of 100 Hz to 100 kHz was dominated by system noise, disallowing interrogation of low-frequency relaxation effects. This initial investigation compiles the comparative knowledge for relaxation responses in both direct electrical and standoff electromagnetic measurements while demonstrating high-frequency signatures of low-conductivity soils and sample volume effects. As a result of this research, a new EMI system is in development addressing a lower range of frequencies for continued relaxation process investigations. [ABSTRACT FROM AUTHOR]

An original ZnO nanowire (NW) architecture has been developed, entirely based on a soft chemistry approach, and thoroughly assessed through optical measurements and electromagnetic simulations. This architecture relies on the photoimprinting of a sol–gel ZnO‐based photosensitive seed layer combined with the subsequent localized hydrothermal growth of ZnO NWs. The optimization of the elaboration protocol has been shown to lead to uniform and reproducible linear and periodic gratings of ZnO NWs with a width/pitch of 2/4 µm. The NW gratings are compared with full‐covered samples (NWs coating) elaborated from a nonimprinted seed layer. A morphological study reveals that NW gratings present a peculiar hedgehog‐like profile. Standard and angle‐resolved photoluminescence studies demonstrate that the ZnO NWs visible emission is strongly modified by the presence of NW gratings and that its red part is directionally extracted and enhanced by a factor of up to 2. The electromagnetic simulations performed for both samples highlight the role of the gratings acting as coupled microcavities that boost the ZnO emission through light localization and diffractive mechanisms. It enables the extraction of the resonant photons at specific angles and wavelengths. [ABSTRACT FROM AUTHOR]

We present the design and the performance evaluation of a new interconnect for large-scale densely packed electronically scanned antenna arrays that utilize a high-speed digital board-to-board vertical connector. The application targets microwave tissue, imaging in the frequency range from 3 GHz to 8 GHz. The tissue-imaging arrays consist of hundreds of active antenna elements, which require low-reflection, low-loss, and low-crosstalk connections to their respective receiving and transmitting circuits. The small antenna size and the high array density preclude the use of coaxial connectors, which are also expensive and mechanically unreliable. Modern board-to-board high-speed connectors promise bandwidths as high as 12 GHz, along with high pin density, mechanical robustness, and low cost. However, their compatibility with the various transmission lines leading to/from the miniature printed antenna elements and microwave circuitry is not well studied. Here, we focus on the design of the transitions from coplanar waveguide transmission lines to/from a high-speed vertical connector. The performance of the interconnect is examined through electromagnetic simulations and measurements. Comparison is carried out with the expensive sub-miniature push-on sub-micro coaxial connectors commonly used in miniature radio-frequency electronics. The results demonstrate that high-speed vertical connectors can provide comparable performance in the UWB frequency range. [ABSTRACT FROM AUTHOR]

Optical thermometers are advantageous for temperature measurement in electromagnetic fields and aggressive environments; however, their composition mostly relies on materials doped with expensive and resource-limited rare earth ions. In this article, we describe the application of calcium aluminate doped with transition metal ions (Mn2+ and Cr3+) in optical thermometry, employing optical fibres for signal transmission. Upon excitation with 450 nm laser diode radiation, changes in the luminescence of Mn2+ ions in the 500–550 nm band are followed along with changes in the Cr3+ band at 750–800 nm. The application has been tested in the temperature range from 20 °C to 800 °C. The temperature dependence of Cr3+ luminescence encompasses the high-temperature range, whereas the luminescence band of Mn2+ ions gives an increase in the total intensity and provides a more consistent change in the range from 400 °C to 550 °C. [ABSTRACT FROM AUTHOR]

One of the shortcomings of the classical electromagnetic method of Zavoisky is sensitivity to the non-one-dimensionality of the flow behind the wave front. In this paper, it is proposed to use a four-pin gauge to correct measurements. Two signals are recorded from -shaped gauges, one of which is located in a plane tangent to the front, and the other in a plane parallel to the direction of wave propagation. Next, the two signals are combined into a true velocity signal that is insensitive to the curvature of the front. The second difficulty that arises in electromagnetic measurements is the rather large size of the gauges. Typically, the length of the working arm is about 1 cm. An analysis of the potential distribution in the gauge shows that the proposed combined gauge is equivalent to two sensors of zero width, and the effective length is the distance between the midlines of the leads. It is shown that the value of can be reduced to 1.5–2 mm with a lead width of about 0.5 mm. This makes it possible to perform local measurements at spots of millimeter size and use small-size charges. These improvements bring electromagnetic measurements closer to the level of modern optical techniques while using much cheaper equipment. [ABSTRACT FROM AUTHOR]

In this paper, a prediction system has been developed using machine learning techniques to obtain the conduction emission levels ensure they remain below the limit values specified in test standards. An LED (Light-emitting diode) driver circuit based on a buck-boost type DC-DC converter has been employed in the experiments. Standards-compliant conducted emission testing processes have been performed and measurement results have been used to generate datasets. These datasets have been organized and processed according to the targeted machine learning methods. GPR, has achieved the highest success rate of 99% among ANN and regression methods. In order to improve the performance in EMI harmonic prediction, training was conducted using deep learning, and the obtained model has a mean squared error of 0.78. The harmonics are well captured with the method and the results are in good agreement with measurements. Consequently, the number of required pre-compatibility tests for a similar topology can be significantly reduced. [ABSTRACT FROM AUTHOR]

Possible interference sources for our aerosol lidar setup with transient recorders have been assessed. This was done by two methods: a spectrum analysis of the lidar signals in order to detect radio-frequency interference and measurements of the electromagnetic interference caused by the laser power supply. We found disturbances in the analog channels of the transient recorders, presumably caused by aging effects of our older recorders. An easy method on how the signal-to-noise ratio can be improved retrospectively is presented. We also show that the usage of two-way radio at our location leads to a noticeable radio-frequency interference in the lidar profiles. Further, we present measurements of the electromagnetic interference caused by the laser power supply, which may lead to disturbances in the lidar profiles if the transient recorders are placed next to it. [ABSTRACT FROM AUTHOR]

A sampling of the environment around inert space objects has determined, which linear and nonlinear waves are created by moving space debris of all sizes. Plasma waves excited by satellites and space debris moving through the Earth's plasma in low earth orbit have been measured with in situ electric field sensors on other satellites. These orbit driven plasma waves are of interest for proximity detection of space debris and sources of electrostatic and electromagnetic noise on spacecraft. Satellites and other space objects moving through the near-earth ionosphere between 200 and 1000 km altitude become electrically charged by both electron collection and photo emission in sunlight. These hypersonic, charged objects can excite a wide range of plasma waves. Measurements with the Radio Receiver Instrument (RRI) on the Swarm-E satellite have shown that electromagnetic plasma waves from known objects can be observed out to ranges of tens of kilometers. The amplitude, spectral, and polarization changes of the RRI data are consistent with electromagnetic, compressional Alfvén waves launched by charged space objects traveling across magnetic field lines. In addition, electrostatic lower hybrid waves or nonlinear ion acoustic pinned oscillations may have been self-generated and measured on the Swarm-E satellite. It is proposed that measurements of these waves with local electric field measurements or remote electromagnetic wave scatter may be useful to design systems for the location of orbiting objects. Spatial and temporal details of spacecraft charging are key to understanding the extent of waves associated with the object motion in space plasmas. [ABSTRACT FROM AUTHOR]

We present time‐correlated ultra‐high‐speed video camera and electromagnetic field measurements of the attachment processes in a natural negative cloud‐to‐ground stroke. The video camera frame exposure time and pixel resolution were 740 ns and 0.91 m/pixel, respectively. The common streamer zone (CSZ) was first observed 2.52 µs preceding the first frame showing the return stroke (RS) in progress, when the upward and downward leader‐tips were 9.8 m apart. In the next frame, the two leaders were observed to have propagated toward each other within the CSZ, with their tips being 0.91 m apart. Our observations show with unprecedented precision/clarity that (a) the slow front in the field waveform is associated with the CSZ, and (b) the "proper" start of the RS is marked by the onset of the fast transition in the field waveform which occurs at the completion of the attachment processes (when the upward and downward leaders have merged). Plain Language Summary: Detailed observations of how cloud‐to‐ground lightning attaches to ground remain very difficult to obtain. This is because the associated processes occur on a microsecond‐scale (or faster), making it challenging to perform time‐correlated multi‐instrument measurements. In this study, we present time‐correlated observations of ultra‐high‐speed video and electromagnetic fields, which provide new insights regarding the lightning attachment processes. These processes comprise the so‐called breakthrough phase of lightning attachment when two oppositely charged leaders (one from the thundercloud and one from ground or ground‐based object) merge with each other. Key Points: Time‐correlated multi‐sensor observations (with camera exposure time of 740 ns) of the natural lightning attachment processes were madeThe slow front portion of the field waveform is associated with the time‐evolution of the common streamer zoneFast‐transition onset in the field waveforms occurs when the upward and downward leaders fully merge ("proper" start of return stroke) [ABSTRACT FROM AUTHOR]

In recent decades, the background level of electromagnetic fields (EMFs) has increased extremely. One of the decisive factors influencing this increase is the increase in the quality, volume, and speed of voice and data services of mobile operators. This paper deals with the protection of the internal environment from the negative effects of EMFs through elements made of metal materials that absorb this radiation. For the purposes of this research, a series of measurements were carried out on individual days of the week and hours during the day. The results of the measurements were evaluated by the ANOVA method. The aim was to obtain a summary overview of the effects of electromagnetic fields and propose measures for their elimination in the interior. Therefore, measurements of electromagnetic fields were also carried out using shielding elements made of various metal materials, and a comparison of their shielding efficiency was subsequently made. Applications of shading blinds with the highest shading efficiency were recommended to increase safety, protect people's health from its effects, and prevent electromagnetic fields. [ABSTRACT FROM AUTHOR]

This study proposed a simple method to evaluate the spectral reflectance of the inner wall of a vacuum chamber. A method for calculating spectral emission coefficients by taking the spectral reflectance of the chamber inner wall into account was proposed. Furthermore, plasma diagnosis based on optical emission spectroscopic (OES) measurement was performed so as to obtain radial dependence of electron temperature Te and density Ne of a radio frequency inductively coupled Argon (Ar) plasma by applying a collisional-radiative model to radially resolved emission spectra of the Ar plasma assuming axial symmetry. In addition, Langmuir probe measurement and electromagnetic simulation were performed and compared with the OES-based plasma diagnosis results. The spectral radiance compensation improved the diagnostic result by 0.6% and 3.1% for Te and Ne, respectively. [ABSTRACT FROM AUTHOR]

A model is proposed for group chase and escape using chemotactic movements only. In the proposed model, the movement depends on the concentration of the chemical substances released by each agent. Chemotaxis-based interactions propagate slower and later, and exist locally between agents, making groups chase and escape under more uncertain circumstances than in cases where agent distance measurements use electromagnetic waves, such as visible light. Numerical results with the model demonstrate that maintaining a longer distance between the chasers and targets is a better strategy for each group. [ABSTRACT FROM AUTHOR]

In this study, we investigated the capacitive effect and the electromagnetic coupling on the measurement chain induced by impact experiments with a gas gun or powder gun. Reduced bandwidth and noise were noticed on experimental signals. Rogowski coil measurements were added on the cables to characterize the electromagnetic coupling. The perturbation currents on the cables were quantified depending on the configuration. The gauge, the transmission line and the conditioning system were modeled. The calculations reproduced the electrical wave arrival time, the transmission line transfer impedance and the conditioning system transfer impedance; and the bandwidth limitation has been displayed. A capacitive effect with the piezoresistive manganin gauge embedded into the sample was identified, depending on the experimental setup. [ABSTRACT FROM AUTHOR]

The quantum zeno effect slows down the quantum system's time evolution under frequent measurements. This paper aims to study this quantum effect by introducing the definition of time based on an irreversible thermodynamic analysis of quantum systems. Consequently, the quantum zeno effect requires (i) high values of the electromagnetic entropy generation rate related to the spontaneously down-converted light and (ii) a decrease in the quantum system's entropy value. So, the quantum zeno effect is a quantum process related to the interaction between a quantum system and the electromagnetic waves of the measurement device, causing a quantum thermodynamic stationary state. Last, the fundamental role of irreversibility emerges. [ABSTRACT FROM AUTHOR]

In the present work, some tests on the electromagnetic interference issues of a new designed and constructed axial flux permanent magnet generator have been presented. The machine itself has multiple special laminated cores (i.e., 12) and 24 windings in the stator component with two active sides. Machine operates in 3 phases and uses disc type permanent magnets on two rotors at two sides in a sandwiched formation. Rotors have 32 magnets and freely rotates at the vicinity of stable stator within a certain air gap. The electromagnetic interference measurements have been realized for different distances and directions from the machine. Besides, the effects of different frequencies are also evaluated following the tests. It has been concluded that the shielding material shape is very important for the optimum shielding results. [ABSTRACT FROM AUTHOR]

Whistler mode quasiperiodic (QP) emissions are electromagnetic waves at frequencies between about 0.5 and 4 kHz observed in the Earth's inner magnetosphere, which are characterized by their nearly periodic time modulation of the wave intensity. Although they have been studied using both ground-based and satellite instruments for already a few decades, their origin remains unclear. Recent studies of these emissions revealed that, on top of the main modulation period, some of the events exhibit an additional fine inner intensity modulation. We use high-resolution electromagnetic wave measurements obtained by the low-altitude DEMETER spacecraft to systematically study the presence/absence of such fine inner structure and the corresponding fine inner modulation periods. Altogether, as many as 251 events are analyzed. Out of these, the clear fine inner modulation is observed for 71 events, only unclear fine inner modulation is observed for 63 events, and the fine inner modulation is completely absent for 117 events. We show that the fine inner structure tends to occur primarily for QP events with shorter modulation periods. The fine inner modulation periods are on the order of few seconds, corresponding to bounce times of whistler mode waves in between the hemispheres. They typically stay quite constant within a single event, and they tend to be lower at larger geomagnetic latitudes (L-shells). Interestingly, the fine inner modulation periods are positively correlated with the main QP modulation periods. The results obtained are of interest for understanding possible mechanisms responsible for the generation of QP events. [ABSTRACT FROM AUTHOR]

The concept of a "smoke ring" in electromagnetic fields can be used to describe the spatial distribution and diffusion of electromagnetic fields with either frequency or time. This provides an intuitive basis for the qualitative interpretation of artificial-source electromagnetic measurement results. The existing discussions regarding this field of study have mainly focused on the smoke rings of a magnetic dipole or loop source. In the present work, smoke rings of other commonly used grounded-wire sources in the time domain are investigated. The results show that the smoke ring of grounded-wire sources is more complex than that of magnetic sources. A grounded-wire source can generate an induced current in both horizontal and vertical directions. The horizontal induced current includes positive and negative parts. Both parts of the horizontal induced current maximum diffuse downward perpendicular to the surface, but the diffusion velocity of the negative part is faster, approximately 5.6 times that of the positive part. The vertical induced current maximum diffuses at 45° from the grounded surface with a velocity approximately 5 times that of the positive horizontal induced current. The smoke ring of the horizontal induced current closely resembles a basin, while that of the vertical induced current is more similar to two separate cylinders. Finally, the imaging depth based on horizontal and vertical induced currents is obtained by the statistical relationship between the induced current maximums and the diffusion depth, which are equal to 1.4 times and 1.25 times the diffusion depth, respectively. [ABSTRACT FROM AUTHOR]

To solve scientific and practical problems in the field of electromagnetic measurements, a detailed magnetic characteristic of inhomogeneous media used in various devices is required. The characteristic was obtained from the magnetization of the basic element of the medium — a chain of granules, spheres. To measure magnetic fluxes in a chain along its cores of different radii, it is proposed to use circular sensors-contours on printed circuit boards. The placement of circular sensors between the contacting spheres of the magnetized chain made it possible to determine the magnetic properties of not only the cores of the chain, but also its quasi-continuous tube-layers bounded by adjacent sensors. According to the values of the magnetic flux experimentally measured by sensor-circuits in eight cores of the chain with relative radii of 0.2–0.9 at a magnetizing field strength in the range of 10–55 kA/m, we established the values of the magnetic flux in seven tube-layers with relative radii of 0.25–0.85. The values of the magnetic susceptibility of the tube-layers were determined, which decrease according to an inverse power dependence with an exponent of 2.4 with increasing relative radius. In relatively short chains with the number of spheres 2–8, the values of the demagnetizing factor of tube-layers are established and functionally approximated. The results obtained can be used to study the conditions for the formation of zones responsible for the magnetic capture of magnetically active particles between the granules of the working elements (matrix type) of polygradient magnetic separators and analyzers. [ABSTRACT FROM AUTHOR]

Abstract. Possible interference sources for our aerosol lidar setup with transient recorders have been assessed. This was done by two methods: a spectrum analysis of the lidar signals in order to detect radio-frequency interference and measurements of the electromagnetic interference caused by the laser power supply. We found disturbances in the analog channels of the transient recorders, presumably caused by ageing effects of our older recorders. An easy method on how the signal-to-noise-ratio can be improved retrospectively is presented. We also show that the usage of two-way radio at our location leads to a noticeable radio-frequency interference in the lidar profiles. Further, we present measurements of the electromagnetic interference caused by the laser power supply, which may lead to disturbances in the lidar profiles if the transient recorders are placed next to it. [ABSTRACT FROM AUTHOR]

The 2011 Tohoku-oki earthquake (Mw 9.0) was characterized by a huge fault slip on the shallowest part of the plate interface, where fault behavior had been believed to be aseismic. In this study, we modeled the two-dimensional resistivity distribution across the slip area based on ocean-bottom electromagnetic measurements to understand the physical properties around the plate interface controlling fault rupture processes. The optimal 2D resistivity model showed a conductive area around the shallowest plate interface where the huge coseismic slip was observed, whereas the deeper plate interface where the fault rupture was nucleated was relatively more resistive. The shallowest plate interface was interpreted to have a high pore seawater fraction, whereas the deeper interface was interpreted as a dry area. These findings are consistent with the hypothesis that aseismic frictional conditions changed to conditions enhancing fault rupture when the rupture propagated to the wet, clay-rich shallowest plate area. The optimal resistivity model also revealed a conductive area under the outer-rise area of the Pacific Plate. This finding supports the existence of a hydrated oceanic crust that supplied aqueous water to the subduction zone, including to the huge fault slip area. [ABSTRACT FROM AUTHOR]

The 2011 Tohoku-oki earthquake (Mw 9.0) was characterized by a huge fault slip on the shallowest part of the plate interface, where fault behavior had been believed to be aseismic. In this study, we modeled the two-dimensional resistivity distribution across the slip area based on ocean-bottom electromagnetic measurements to understand the physical properties around the plate interface controlling fault rupture processes. The optimal 2D resistivity model showed a conductive area around the shallowest plate interface where the huge coseismic slip was observed, whereas the deeper plate interface where the fault rupture was nucleated was relatively more resistive. The shallowest plate interface was interpreted to have a high pore seawater fraction, whereas the deeper interface was interpreted as a dry area. These findings are consistent with the hypothesis that aseismic frictional conditions changed to conditions enhancing fault rupture when the rupture propagated to the wet, clay-rich shallowest plate area. The optimal resistivity model also revealed a conductive area under the outer-rise area of the Pacific Plate. This finding supports the existence of a hydrated oceanic crust that supplied aqueous water to the subduction zone, including to the huge fault slip area. [ABSTRACT FROM AUTHOR]

Even in the field of electromagnetic compatibility, low measurement uncertainty means high measurement quality. Although there are standardized procedures for obtaining the uncertainty of such a measurement, which facilitate uncertainty estimation, modern approaches show further reduction possibilities. The paper presents an alternative approach to reducing measurement instrument uncertainty in the case of electromagnetic interference measurement based on many years of our experience and a large number of measurements in this field. In the paper, two different methods of uncertainty reduction are described. The first method is based on a detailed analysis of the sources of uncertainty and the subsequent division of the analyzed frequency band into more subranges. Another method uses the choice of the antenna factor, which also contains information about the test site where the measurement is carried out. In this way, despite a lengthy analysis, it is relatively easy to achieve a measurement instrument uncertainty that is below the maximum measurement uncertainty given by the CISPR standard. [ABSTRACT FROM AUTHOR]

We propose a method to reconstruct the electrical current density from acousticallymodulated boundary measurements of time-harmonic electromagnetic fields. We show that the current can be uniquely reconstructed with Lipschitz stability. We also report numerical simulations to illustrate the analytical results. [ABSTRACT FROM AUTHOR]

Periodically testing the performance of any biological safety cabinet or other sterilization chambers is mandatory; hence, the importance of evaluating the effects of error factors on this performance arises. Until now, despite the necessity of disinfection against many microorganisms, particularly protection against the current pandemic, international standards for the manufacturing and evaluation of safety cabinets did not recommend testing the ultraviolet C performance inside these safety cabinets. The main aim of this paper is to use the sensitivity coefficient as one of the essential terms in uncertainty evaluation, to study the effect of different distances and tilt angles on the irradiance and, hence, the uniformity inside the cabinet or chamber. It was found that the homogeneity of the distribution of irradiance levels along the irradiated area was significantly affected by the distance and angle. The results obtained utilizing the sensitivity coefficient indicated that a simple increase in distance will result in a considerable loss in the irradiance value reaching around 30%. Every 5° increment in the tilt angle causes a decrement in the irradiance value by about 14% compared to the original value (0°); hence, the uniformity decreased significantly by around 45%. These effects may reflect on the sterilization performance of the cabinet as an essential process. At the end of this paper, due to the importance of considering these measurements and the effect of the two parameters on irradiance and, hence, the uniformity, the author recommends that these measurements be added to international standards for safety cabinets manufacturing and evaluation. The recommendation may help to focus more on evaluating the ultraviolet C homogeneity performance inside biosafety cabinets. [ABSTRACT FROM AUTHOR]

Wireless communication devices such as wireless LANs and RFIDs are essential for smart home appliances and IoT (Internet of Things) devices in Smart Cities. When measuring the high‐frequency noise generated by devices, wireless signals of wireless communication devices and high‐frequency noise are measured at the same time. As a result, spectrum analyzers have insufficient dynamic range, or the excess signal from wireless communication devices causes harmonic distortion of the mixer inside the receiver, resulting in inaccurate measurements. Accordingly, a band rejection filter (BRF) is required to attenuate the radio signal. CISPR 16‐2‐3:2016+A1: 2019 assumes that impedances are matched for measurement, so if the impedance mismatch is large, the expanded uncertainty specified in CISPR 16‐4‐2:2011+A1:2014+A2:2018 increases. In this study, we propose a new BRF with impedance matching in the attenuation range and show its principle. As a result, the extended uncertainty could be reduced to 3.96 dB for the BRF of this study compared to 10.63 dB for the conventional BRF. In addition, the method comparison of CISPR 16‐2‐3:2016+A1: 2019 and vector network analyzer shows that the difference in attenuation of the conventional BRF was about −0.8 to 3.3 dB, whereas the BRF in this study were about −0.2 to 0.3 dB. The reduction of the expanded uncertainty and the good measurement results confirm the high usefulness of the CISPR 16‐2‐3 measurement system for the measurement of weak electromagnetic noise. [ABSTRACT FROM AUTHOR]

It was recently suggested that the sparking of grape dimers in microwave ovens is due to the interaction of morphology-dependent resonances in aqueous spheres. However, evidence for microwave resonances in individual grape-sized aqueous spheres has remained weak and is open to interpretation. In this work, we provide new experimental evidence for size-dependent resonances in hydrogel spheres via calorimetric measurement of the electromagnetic energy absorbed by hydrogel spheres under microwave irradiation. Using finite-element simulations, we predict the resonant behavior of grape-sized aqueous spheres and further explore the differences between mode intensities in free-space and various in situ positions of a microwave oven. The lowest morphology-dependent resonance—a magnetic dipolar mode—is experimentally confirmed, appearing at the predicted diameter of ∼1.35 cm. Finally, experimental evidence for higher order modes in larger spheres is suggestive but remains unresolved. [ABSTRACT FROM AUTHOR]

The measurement of the transient pulsed electromagnetic (EM) field is essential for analyzing electromagnetic compatibility. Due to their good performance, D-dot sensors, combined with numerical integration computation for signal recovery, are commonly used to measure electromagnetic pulses (EMPs). However, the integration approach is occasionally flawed due to a non-ideal frequency response or noise, causing distortions in the reconstructed signal. In order to better understand the dynamic performance of the sensor, a nonlinear Hammerstein model is employed in the system identification for the sensor with the calibration data collected in the laboratory environment. When identifying the linear component based on the ultra-wideband characteristics of the measured transient pulse, a two-step identification approach with two different pulse excitation modes, low frequency and high frequency, is utilized to conduct the modeling across the entire frequency range. Based on the reliable identification and modeling of the D-dot sensor, a compensation system that corresponds to the nonlinear Hammerstein model has been developed for the practical signal recovery of the incident E-field. After compensation, the dynamic characteristics of the sensor are significantly improved, and the system compensation approach outperforms the integration method in signal recovery for the incident E-field. [ABSTRACT FROM AUTHOR]

It is highly desirable for electromagnetic wave (EMW) absorbers to have a low high filler ratio in matrix and low matching thickness. Herein, atomically dispersed Mn sites are introduced into N-doped carbon nanotubes (Mn−N x /NCNT) to this aim. Structural characterizations indicate that the as-fabricated Mn−N x /NCNT exhibits tubular morphology with a large surface area of 295.56 m2 g−1 and the Mn sites are atomically dispersed in the NCNT with a loading of 1.56 wt%. Benefiting from the unique structural advantages, Mn−N x /NCNT has excellent EMW absorption property, showing an effective absorption bandwidth of 4.15 GHz at a filler ratio of only 7% and a matching thickness of only 1.7 mm. The experimental measurements of electromagnetic parameters and density functional theory calculation results indicate that electronic structure and polarizability of the NCNTs are adjusted by the atomically dispersed Mn sites, leading to the increase in conduction and polarization losses of Mn−N x /NCNT, and thus in the EMW property. Our results demonstrate that hollow nanotubes containing metal single-atoms are potential EMW absorbers with a lightweight feature. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract—The technology of ground-based and airborne helicopter-based electromagnetic survey measurements aimed at the assessment of prospective areas for water is described. For the complex geocryological conditions of Yakutia, the effectiveness of the time-domain and frequency-domain transient electromagnetics in identifying the zones recommended for water-well drilling is demonstrated. [ABSTRACT FROM AUTHOR]

This article presents local shielding techniques applied to a half-bridge inverter leg with the aim to reduce the common-mode (CM) current noise at converter’s dc input. The research study is conducted for 650-V enhancement mode Gallium Nitride power transistor switches. Main contributors of parasitic capacitances referred to the inverter-leg middle point node are identified. Then, shielding solutions are proposed to reduce the CM current emission by these capacitances. Respecting the precautions concerning the isolation of CM currents of the half-bridge inverter leg, the electromagnetic compatibility measurement setup is developed. Experimental step-by-step addition of local shielding copper layers to different contributors of middle point capacitance shows progressive attenuation of CM noise spectra. [ABSTRACT FROM AUTHOR]

Electromagnetic waves emitted during a tokamak discharge can be partially ascribed to coupling with plasma waves. In particular, in the presence of runaway electrons, the electromagnetic waves deliver information, otherwise inaccessible, about kinetic instabilities excited by the fast particles. Experiments aimed at studying radio frequency emissions from runaway electron scenarios during different stages of plasma discharge have been carried out at the Frascati Tokamak Upgrade. Frequencies in the range of lower hybrid and whistler waves have been explored, in the presence of relativistic electrons with different energies, ranging from a few to tens of MeV. A pronounced sensitivity of the radio frequency measurements in detecting driven instabilities is observed, providing the possibility to exploit this kind of technique as a monitor of the instability processes and for studies of the fast electron activity. In particular, in this work, we propose a simplified analysis of the frequency scaling of a specific family of kinetic instabilities arising at the lower hybrid frequency range during the current ramp-up stage. The study is performed with respect to the density profile and the wave vector coupling conditions and is aimed at obtaining a rough estimate of the most likely radial location of the interaction between the runaway electron beam and plasma waves at the emission times of the observed signals. [ABSTRACT FROM AUTHOR]

The advent of fast sensing technologies allow for real-time model updates in many applications where the model parameters are uncertain. Once the observations are collected, Bayesian algorithms offer a pathway for real-time inversion (a.k.a. model parameters/inputs update) because of the flexibility of the Bayesian framework against non-uniqueness and uncertainties. However, Bayesian algorithms rely on the repeated evaluation of the computational models and deep learning (DL) based proxies can be useful to address this computational bottleneck. In this paper, we study the effects of the approximate nature of the deep learned models and associated model errors during the inversion of borehole electromagnetic (EM) measurements, which are usually obtained from logging while drilling. We rely on the iterative ensemble smoothers as an effective algorithm for real-time inversion due to its parallel nature and relatively low computational cost. The real-time inversion of EM measurements is used to determine the subsurface geology and properties, which are critical for real-time adjustments of the well trajectory (geosteering). The use of deep neural network (DNN) as a forward model allows us to perform thousands of model evaluations within seconds, which is very useful to quantify uncertainties and non-uniqueness in real-time. While significant efforts are usually made to ensure the accuracy of the DL models, it is widely known that the DNNs can contain some type of model-error in the regions not covered by the training data, which are unknown and training specific. When the DL models are utilized during inversion of EM measurements, the effects of the model-errors could manifest themselves as a bias in the estimated input parameters and as a consequence might result in a low-quality geosteering decision. We present numerical results highlighting the challenges associated with the inversion of EM measurements while neglecting model-error. We further demonstrate the utility of a recently proposed flexible iterative ensemble smoother in reducing the effect of model-bias by capturing the unknown model-errors, thus improving the quality of the estimated subsurface properties for geosteering operation. Moreover, we describe a procedure for identifying inversion multimodality and propose possible solutions to alleviate it in real-time. [ABSTRACT FROM AUTHOR]

The ALICE Collaboration completed the upgrade of the detector and is now commissioning for the beginning of the data taking during LHC Run 3. In parallel, R&D activities and simulation studies are being performed to define the future of the experiment beyond LHC Run 3. Two detector upgrades are foreseen for the next long shutdown (LS3). The first is the replacement of the three layers of the inner tracking system closest to the beam with a novel vertex detector consisting of curved wafer-scale ultra-thin silicon sensors arranged in perfectly cylindrical layers to improve impact parameter resolution and significantly extend the physics capability for the study of the heavy-flavor production and the low-mass dielectrons. The second upgrade for the LS3 is the addition of a Forward Calorimeter detector at large rapidity consisting of a Si-W electromagnetic calorimeter with pad and pixel readout, that will equip the experiment with unique capabilities to measure small-x gluon distributions via prompt photon production. A proposal of a next-generation heavy-ion experiment for LHC Run 5 is also in preparation and will be discussed. The aim is to perform novel measurements of the electromagnetic and hadronic probes of the QGP, such as the production of multiply-charmed baryons, which have so far been inaccessible, both because of detector performance and luminosity. The concept of the new apparatus foresees an extensive usage of thin silicon sensors for tracking and a modern particle identification system, combining a silicon-based time of flight detector, a RICH detector, an electromagnetic calorimeter and a muon system. [ABSTRACT FROM AUTHOR]