Energy Measurements Research Articles

Design of multi-channel electronic prototype for 101Sn energy level lifetime measurement

In this study, a 32-channel front-end data acquisition unit (DAQU) with high temporal resolution and count rate was developed at the Heavy Ion Research Facility in Lanzhou (HIRFL), China, to measure the lifetime of 101Sn on the Spectrometer for Heavy Atoms and Nuclear Structure. The DAQU data analysis module uses a field programmable gate array (FPGA) to implement and time stamp extraction through an FPGA-based tapped delay line (TDL) time-to-digital converter. The energy measurements were implemented using a trapezoidal algorithm and a sliding baseline averaging method. The DAQU was tested and calibrated using a pulse generator and cosmic rays. The results show that the system had a dead time of less than 500 ns, a dynamic range of “0” to “500” mV, and an energy resolution of better than 4.8‰ (full width at the half-maximum, FWHM). In addition, the single-channel temporal resolution under multi-channel settings surpasses 111.2 ps (FWHM), satisfying the experiment's requirements for the electronics system.

Simulation of the 2E Technique on neutron multiplicity measurement as a function of fragment mass in spontaneous fission of 252Cf

A Monte Carlo simulation algorithm to investigate the measurement of the average prompt neutron multiplicity as a function of pre-neutron mass, ν(A), for fragments from the spontaneous fission of 252Cf is presented. The input data consist of experimental measurements of the kinetic energy and mass distributions obtained by Göök et al., and the values of ν(A) calculated using the FIFRELIN model by Piau et al., νth(A). We analyze the output curve, νsim(A), obtained by simulation of the 2E technique, which should ideally match νth(A). However, we find that νsim(A) exhibits a maximum value at A≈122, close to mass symmetry, while νth(A) has a maximum at A≈118. Additionally, we observe that νsim(A) > νth(A) for A< 90 and A> 169, respectively. We attribute this discrepancy to inaccuracies in the relationship between provisional mass and the pre-neutron mass used in the 2E technique for data processing in each fission event.

Studies on a hadronic calorimeter with MPGD technology for a future Muon Collider experiment

In the context of the European strategy for particle physics, the Multi-TeV Muon Collider has emerged as a compelling alternative for advancing our understanding of the Standard Model, after the full exploitation of the High-Luminosity LHC. The physics programme at the Muon Collider includes precise measurements in the Higgs boson sector and the search for new physics at the TeV scale. Achieving these goals relies on accurate full event reconstruction, including the identification and precise four-momentum estimation of various particles. The Particle Flow (PF) algorithm is one of the most suitable approach for this task, exploiting information from tracking, calorimeter, and muon detectors for particle identification and measurements of their momenta/energies. Tracking detectors measure charged particle momenta, while calorimeters provide energy measurements for photons and neutral hadrons. Therefore, a combination of an exceptional tracking system and high-granularity calorimeters is necessary. However, one of the biggest challenges for a future experiment at the Muon Collider is to discriminate the product of the μμ collisions from the intense beam-induced-background (BIB), due to the unstable nature of muons, whose decay products interact with the detector material. To address this, an innovative hadronic calorimeter (HCAL) based on Micro Pattern Gas Detectors (MPGDs) is proposed. MPGDs offer robust technology for high radiation environments and a high granularity for precise spatial measurements. Dedicated studies are needed to assess and optimize the performance of an MPGD-based HCAL, including the development of medium-scale prototypes for performance measurements. The response of HCAL to incoming particles is examined through Monte Carlo simulations using Geant4, comparing the performance of digital and semi-digital readouts, with energy resolution as the figure of merit. The simulated geometry will be integrated into the Muon Collider software to study its impact on jet reconstruction within the full apparatus and in the presence of BIB. The simulation will be also validated through the test of a small-size calorimeter cell equipped with advanced resistive MPGD technologies, namely resistive MicroMegas, resistive μRWELL and RP-WELL.

A state-selected continuous wave laser excitation method for determining CO2's rotational state distribution in a supersonic molecular beam.

State-resolved experiments can provide fundamental insight into the mechanisms behind chemical reactions. Here, we describe our methods for characterizing state-resolved experiments probing the outcome of the collision between CO2 molecules and surfaces. We create a molecular beam from a supersonic expansion that passes through an ultra-high vacuum system. The CO2 is vibrationally excited by a continuous wave infrared (IR) laser using rapid adiabatic passage. We attenuate the fractional excitation using a CO2 absorption cell in the IR beam path. We combine Monte Carlo simulations and molecular beam energy measurements to find the initial rotational state distribution of the molecular beam. We find that our pure CO2 beam from a 300K source has a rotational temperature of ∼26K.

The influence of ripple on DC energy measurement and the improvement of wavelet threshold function filtering method

DC energy has been applied in the construction of DC power grids, photovoltaic power generation, energy storage, and rapid charging of electric vehicles. The application of DC energy is of great significance for energy conservation, emission reduction, carbon reduction, and efficiency increase. In this paper, the reasons for the decrease in DC energy measurement accuracy caused by ripples in voltage and current are analyzed. The minimum requirements of ripples for DC energy meters are analyzed, and the traditional filtering method based on wavelet threshold is studied. An optimized and fast iterative wavelet threshold function was designed, the current signal of electric vehicle charging was selected, and the effectiveness of the algorithm proposed in this paper was verified through simulation.

Direct numerical simulations of an airfoil undergoing dynamic stall at different background disturbance levels

Thin airfoil dynamic stall at moderate Reynolds numbers is typically linked to the sudden bursting of a small laminar separation bubble close to the leading edge. Given the strong sensitivity of laminar separation bubbles to external disturbances, the onset of dynamic stall on a NACA0009 airfoil section subject to different levels of low-amplitude free stream disturbances is investigated using direct numerical simulations. The flow is practically indistinguishable from clean inflow simulations in the literature for turbulence intensities at the leading edge of ${Tu} = 0.02\,\%$ . At slightly higher turbulence intensities of ${Tu} = 0.05\,\%$ , the bursting process is found to be considerably less smooth and strong coherent vortex shedding from the laminar separation bubble is observed prior to the formation of the dynamic stall vortex (DSV). This phenomenon is considered in more detail by analysing its appearance in an ensemble of simulations comprising statistically independent realisations of the flow, thus proving its statistical relevance. In order to extract the transient dynamics of the vortex shedding, the classical proper orthogonal decomposition method is generalised to include time in the energy measure and applied to the time-resolved simulation data of incipient dynamic stall. Using this technique, the dominant transient spatiotemporally correlated features are distilled and the wave train of the vortex shedding prior to the emergence of the main DSV is reconstructed from the flow data exhibiting dynamics of large-scale coherent growth and decay within the turbulent boundary layer.

Compact meta-models to estimate the effects of energy efficiency policies and measures

Compact meta-models to estimate the effects of energy efficiency policies and measures

Upconversion photoluminescence and optical temperature probe of Er3+/Yb3+ co-doped LAZT glass prepared by containerless aerodynamic levitation method

xEr3+/yYb3+ co-doped La2O3-Al2O3-ZrO2-TiO2 ([30-(30/88) × (x + y)]La2O3-[58-(58/88) × (x + y)]Al2O3-4ZrO2-8TiO2: x mol% Er2O3/y mol% Yb2O3, x = 2 mol%, and y = 4, 8, 12, 16, 20 mol%, abbreviated as: LAZT: xEr/yYb) glasses were synthesized using a containerless aerodynamic levitation technique. The maximum phonon energy, fluorescence performance and optical temperature measurement performance of the prepared glasses were studied. Raman test shows that the maximum phonon energy of all glasses is less than 355 cm−1, in which the low phonon energy can provide an excellent internal environment for the induction of fluorescence effects. Under excitation at 980 nm, all samples exhibit noticeable red emission peak centering at 662 nm and feeble green emission peak centering at 549 nm at room temperature. The luminous intensity reaches the highest value at x = 2 mol% and y = 12 mol%, at which the concentration quenching phenomenon occurs. The fluorescence mechanism of LAZT: xEr/yYb involves a double-photon process, in which the energy transfer process (ET) accounts for the main part and the excited state absorption process (ESA) accounts for the secondary part. The fluorescence intensity ratio (FIR) can be used for temperature sensing, and the absolute sensitivity FIR reaches maximum value of 1.3 × 10−2 K−1 at 79 K. These results indicate that the LAZT: 2Er/12Yb glass is expected to become a candidate material for non-contact optical temperature probe.

Bond dissociation energy of O2 measured by fully state-to-state resolved threshold fragment yield spectra.

We have determined the bond dissociation energy of O2 by measuring fully state-to-state resolved threshold fragment yield spectra in the XUV energy region, O2X3Σg-,N″,J″→O(PJ3)+O(S1o3)/O(S2o5). Our results have yielded a bond dissociation energy value of 41 269.19 ± 0.10cm-1, which is consistent with previous measurements but exhibits a significantly lower uncertainty, approximately five times smaller. It is noteworthy that this study is the first to simultaneously achieve fine structure state resolution for the parent O2molecule and spin-orbit state resolution for the O(3PJ) fragments in the measurement of O2 bond dissociation energy. As a result, our findings have established a solid foundation for the obtained data.

The bond energy of UN+: Guided ion beam studies of the reactions of U+ with N2 and NO.

A guided ion beam tandem mass spectrometer was used to study the reactions of U+ with N2 and NO. Reaction cross sections were measured over a wide range of energy for both systems. In each reaction, UN+ is formed by an endothermic process, thereby enabling the direct measurement of the threshold energy and determination of the UN+ bond dissociation energy. For the reaction of U+ + N2, a threshold energy (E0) of 4.02 ± 0.11eV was measured, leading to D0 (UN+) = 5.73 ± 0.11eV. The reaction of U+ + NO yields UO+ through an exothermic, barrierless process that proceeds with 94 ± 23% efficiency at the lowest energy. Analysis of the endothermic UN+ cross section in this reaction provides E0 = 0.72 ± 0.11eV and, therefore, D0 (UN+) = 5.78 ± 0.11eV. Averaging the values obtained from both reactions, we report D0 (UN+) = 5.76 ± 0.13eV as our best value (uncertainty of two standard deviations). Combined with precise literature values for the ionization energies of U and UN, we also derive D0 (UN) = 5.86 ± 0.13eV. Both bond dissociation energies agree well with high-level theoretical treatments in the literature. The formation of UN+ in reaction of U+ with NO also exhibits a considerable increase in reaction probability above ∼3eV. Theory suggests that this may be consistent with the formation of UN+ in excited quintet spin states, which we hypothesize are dynamically favored because the number of 5f electrons in reactants and products is conserved.

Inverse source problem for two-term time-fractional diffusion equation with nonlocal boundary conditions

This paper explores an inverse source problem related to the heat equation, incorporating nonlocal boundary conditions and featuring two-term time-fractional derivatives. The task is to identify a source term that is independent of the spatial variable, as well as to define the temperature distribution based on energy measurements. Since the stated problem cannot be solved by direct use of the generalized Fourier method, we divide the problem into two sub-problems. The well-posedness of each problem is established through the application of the generalized Fourier method.

Microdosimetry at the nanometre level with different techniques

Microdosimetry provides the capability to measure probabilistic distributions of lineal energy in micrometer or sub-micrometer-sized volumes. The shape of these distributions is dependent on the size of the sensitive volume used for scoring, meant to approximate that of the relevant biological target. Recognizing that biological damage and its repair processes occur at different length scales, initiated by damages at the DNA level, single-event distributions can be measured with proportional counters in simulated sites as small as about 30 nm, but hardly below. However, direct measurement of dose-mean lineal energy can be achieved in even smaller site sizes, down to a few nm, using integrated current measurements with an ionization chamber and applying the variance-covariance technique. In this study, we investigate the agreement between dose-mean lineal energy values calculated from single-event distributions and those measured using the variance-covariance technique in photon radiation fields.

Energy efficiency and performance analysis of a legacy atomic scale materials modeling simulator (VASP)

This work tackles the performance and energy consumption analysis of a legacy scientific application, the VASP (Vienna Ab-initio Simulation Package), an application commonly used by physicists and chemists for modeling materials at the atomic scale. Many of these scientific applications have been implemented in Fortran, where energy metrics instrumentation is not straightforward. We obtained performance figures (execution time and energy consumption) by instrumenting the source code using EML. This energy measurement library has been modified to introduce Fortran interfaces for these metrics. The analysis was carried out using different matrix algebra libraries, parallelization techniques, and hardware platforms, emphasizing on the MPI, OpenMP, and CUDA parallel implementations of the algorithms used in VASP. We employ various material specifications (atomic structures) and molecular sizes of a silicon-based crystal to create a set of benchmarks for these specifications, leading to some recommendations for final users regarding performance improvements. The proposed benchmarking technique assists the user in selecting the right combination of problem size, compilers, and parallelization options available in VASP. For a given system platform, the user will be able to determine not only the architecture to use (GPU or multicore processors), but also the appropriate library and parallelization according to the atomic structure and molecular size.

Millijoule Terahertz Radiation from Laser Wakefields in Nonuniform Plasmas.

We report the experimental measurement of millijoule terahertz (THz) radiation emitted in the backward direction from laser wakefields driven by a femtosecond laser pulse of few joules interacting with a gas target. By utilizing frequency-resolved energy measurement, it is found that the THz spectrum exhibits two peaks located at about 4.5 and 9.0THz, respectively. In particular, the high frequency component emerges when the drive laser energy exceeds 1.26J, at which electron acceleration in the forward direction is detected simultaneously. Theoretical analysis and particle-in-cell simulations indicate that the THz radiation is generated via mode conversion from the laser wakefields excited in plasma with an up-ramp profile, where radiations both at the local electron plasma frequency and its harmonics are produced. Such intense THz sources may find many applications in ultrafast science, e.g., manipulating the transient states of matter.

The impact of size on middle-ear sound transmission in elephants, the largest terrestrial mammal.

Elephants have a unique auditory system that is larger than any other terrestrial mammal. To quantify the impact of larger middle ear (ME) structures, we measured 3D ossicular motion and ME sound transmission in cadaveric temporal bones from both African and Asian elephants in response to air-conducted (AC) tonal pressure stimuli presented in the ear canal (PEC). Results were compared to similar measurements in humans. Velocities of the umbo (VU) and stapes (VST) were measured using a 3D laser Doppler vibrometer in the 7-13,000 Hz frequency range, stapes velocity serving as a measure of energy entering the cochlea-a proxy for hearing sensitivity. Below the elephant ME resonance frequency of about 300 Hz, the magnitude of VU/PEC was an order of magnitude greater than in human, and the magnitude of VST/PEC was 5x greater. Phase of VST/PEC above ME resonance indicated that the group delay in elephant was approximately double that of human, which may be related to the unexpectedly high magnitudes at high frequencies. A boost in sound transmission across the incus long process and stapes near 9 kHz was also observed. We discuss factors that contribute to differences in sound transmission between these two large mammals.

Energy Consumption for Furniture Joints during Drilling in Birch Plywood.

The purpose of this study is to support eco-design ideas and sustainable manufacturing techniques by examining the energy consumption related to drilling holes for different furniture connections. The experimental model is a simple piece of furniture made from birch plywood with three different types of joints. Eccentric joints, confirmat screws, and dowel measurements of energy consumption with a CNC drilling and milling machine show different values for every kind of connector. The energy consumption was measured using a portable power quality analyzer, specifically the PQ-box 150 manufactured by A:Eberle GmbH & Co. KG Nürnberg, Germany. This device likely adheres to industry standards for energy measurement, ensuring accurate and reliable results. The measurement process involved recording energy consumption at different stages of the machining process, allowing for the analysis of specific cutting work and total energy consumption for various joint types. Dowels exhibit the lowest energy consumption at 0.105 Wh for one furniture joint, confirmat screws at 0.127 Wh, while eccentric joints, despite their higher energy consumption (0.173 Wh), offer enhanced transportability and assembly flexibility of a piece of furniture. Specific cutting power for one selected piece of furniture was 227.89 J/mm3 for dowels, 190.63 J/mm3 for eccentric joints and 261.68 J/mm3 for confirmat screws.

The environmental impact of the zero energy ready home program on manufactured housing

Manufactured homes, which are built in the factory and shipped to the site, provide economical housing for more than 20 million Americans. To improve energy measures and facilitate deployment of renewable energy systems to achieve net zero energy in manufactured homes, the U.S. Department of Energy (DOE) made public the Zero Energy Ready Home (ZERH) National Program Requirements for manufactured housing in 2022. To understand how these changes will impact the environment and the building’s durability, life cycle assessment and hygrothermal simulations were carried out for a standard manufactured home design and two ZERH designs in Knoxville, Tennessee. The embodied carbon and operational emissions were compared for the standard design and two ZERH designs for a service life of 60 years. Operational emissions were determined using the Building Energy Optimization tool, BEopt, and durability assessment was carried out using WUFI Pro. Life cycle assessment was performed in accordance with ISO 14040 using Athena’s Impact Estimator for buildings. Results indicate that the investment in embodied carbon of the zero energy ready homes is small relative to the savings in operational emissions. The increase in embodied carbon in the zero energy ready homes is offset by the reduction in operational emissions compared to the standard home for the first year of operation. With an investment of 59 kg CO2 eq in embodied carbon, the reduction in operational emissions is approximately 680 kg CO2 eq after one year compared to a construction that meets the prescriptive performance of the building code for manufactured housing.

A Comparative Study of the Life Cycle Inventory of Thermally Sprayed WC-12Co Coatings

In this research, a life cycle inventory (LCI) is developed for tungsten carbide–cobalt (WC-Co) coatings deposited via atmospheric plasma spray (APS), high-velocity oxy-fuel (HVOF), and cold gas spray (CGS) techniques. For the APS process, a mixture of Ar/H2 was used, while the HVOF process was fueled by H2. The carrier gas for CGS was N2. This study aims to determine and quantify the inputs (consumption of inputs and materials) and outputs (emissions to air, soil, water, and waste generation) that could be used in the life cycle analysis (LCA) of these processes. The dataset produced will allow users to estimate the environmental impacts of these processes using WC-Co feedstock powder. To obtain a complete and detailed LCI, measurements of electrical energy, gas, WC-CO powder, and alumina powder consumption were performed (the use of alumina was for sandblasting). Furthermore, emissions like carbon dioxide (CO2), carbon monoxide (CO), and noise were also measured. This practice allowed us to determine the input/output process quantities. For the first time, it was possible to obtain LCI data for the APS, HVOF, and CGS deposition processes using WC-12Co as a feedstock powder, allowing access to the LCI data to a broader audience. Comparisons were made between APS, HVOF, and CGS processes in terms of consumption and emissions. It was determined that the APS process consumes more electrical energy and that its deposition efficiency is higher than the other processes, while the HVOF process consumes a large amount of H2, which makes the process costlier. CGS has comparatively low electricity consumption, high N2 consumption, and low deposition efficiency. The APS, HVOF, and CGS processes analyzed in this study do not emit CO, and CO2 emissions are negligible.

A review on the evaluation models and impact factors of greenhouse gas emissions from municipal solid waste management processes.

The total amount of global municipal solid waste (MSW) will reach 3.5 billion tons by 2050, thereby bringing tremendous environmental pressure, especially global warming. Large amounts of greenhouse gases (GHGs) have been released during MSW management (MSWM). Accounting for GHG emissions is a prerequisite for providing recommendations on appropriate treatment options to mitigate emissions from MSWM systems. There are many methods involved in estimating emissions. This paper summarizes the computing models commonly used in each process of the integrated MSWM system and emphasizes the influence of parameters and other factors. Compared with other disposal methods, landfilling has the highest emissions, commonly estimated using first-order decay (FOD) methods. Emission reduction can be realized through waste to energy (WtE) and resource recovery measures. IPCC is commonly used for calculating direct emissions, while LCA-based models can calculate emissions including upstream and downstream processes, whose results depend on assumptions and system boundaries. The estimation results of models vary greatly and are difficult to compare with each other. Besides, large gaps exist between the default emission factors (EFs) provided by models and those F measured in specific facilities. These findings provide a systematic view for a bettering understanding of MSW emissions as well as the estimating methods and also reveal the key points that need be developed in the future.

Global low carbon transitions in the power sector: A machine learning clustering approach using archetypes

This study presents an archetype-based approach to designing effective strategies for low-carbon transitions in the power sector. To achieve global energy transition goals, a renewable energy transition is critical, and understanding diverse energy landscapes across different countries is essential to designing effective renewable energy policies and strategies. Using a clustering approach, this study identifies 12 power system archetypes based on several features, including energy and socio-economic indicators of 187 UN countries. Each archetype is characterised by distinct challenges and opportunities, ranging from high dependence on fossil fuels to low electricity access, low economic growth, and insufficient contribution potential of renewables. Archetype A, for instance, consists of countries with low electricity access, high poverty rates, and limited power infrastructure, while Archetype J comprises developed countries with high electricity demand and installed renewables. The study findings have significant implications for renewable energy policymaking and investment decisions, with policymakers and investors able to use the archetype approach to identify suitable renewable energy policies and measures and assess renewable energy potential and risks. Overall, the archetype approach provides a comprehensive framework for understanding diverse energy landscapes and accelerating decarbonisation efforts for the power sector.