High-energy Response Research Articles

Measurement principle and electric field analysis of tissue equivalent proportional counter

Abstract TEPC is the preferred device for measuring microdoses due to its excellent organizational equivalence and high energy response. The most important factor affecting its energy response is the electric field distribution in the avalanche region. This paper uses finite element analysis to examine the electric field distribution of a spherical structure with a sensitive area diameter of 2 cm and a cylindrical structure with a sensitive area of 2 cm × 2 cm. While the spherical structure exhibits better isotropy, it has significant distortions in the electric field at the anode wire end, making compensation optimization complex and hindering miniaturization. Cylindrical structures can compensate for the electric field by adding insulators at the anode wire end. When the insulator diameter is 3mm, the optimal protrusion length into the chamber is also 3mm. This lays the foundation for the miniaturization of TEPCs in subsequent research.

A new cloud-based method for composition of healthcare services using deep reinforcement learning and Kalman filtering

Healthcare has significantly contributed to the well-being of individuals around the globe; nevertheless, further benefits could be derived from a more streamlined healthcare system without incurring additional costs. Recently, the main attributes of cloud computing, such as on-demand service, high scalability, and virtualization, have brought many benefits across many areas, especially in medical services. It is considered an important element in healthcare services, enhancing the performance and efficacy of the services. The current state of the healthcare industry requires the supply of healthcare products and services, increasing its viability for everyone involved. Developing new approaches for discovering and selecting healthcare services in the cloud has become more critical due to the rising popularity of these kinds of services. As a result of the diverse array of healthcare services, service composition enables the execution of intricate operations by integrating multiple services' functionalities into a single procedure. However, many methods in this field encounter several issues, such as high energy consumption, cost, and response time. This article introduces a novel layered method for selecting and evaluating healthcare services to find optimal service selection and composition solutions based on Deep Reinforcement Learning (Deep RL), Kalman filtering, and repeated training, addressing the aforementioned issues. The results revealed that the proposed method has achieved acceptable results in terms of availability, reliability, energy consumption, and response time when compared to other methods.

Gamma-Ray Burst Observations by the High-Energy Particle Detector on board the China Seismo-Electromagnetic Satellite between 2019 and 2021

In this paper we report the detection of five strong gamma-ray bursts (GRBs) by the High-Energy Particle Detector (HEPD-01) mounted on board the China Seismo-Electromagnetic Satellite, operational since 2018 on a Sun-synchronous polar orbit at a ∼507 km altitude and 97° inclination. HEPD-01 was designed to detect high-energy electrons in the energy range 3–100 MeV, protons in the range 30–300 MeV, and light nuclei in the range 30–300 MeV n−1. Nonetheless, Monte Carlo simulations have shown HEPD-01 is sensitive to gamma-ray photons in the energy range 300 keV–50 MeV, even if with a moderate effective area above ∼5 MeV. A dedicated time correlation analysis between GRBs reported in literature and signals from a set of HEPD-01 trigger configuration masks has confirmed the anticipated detector sensitivity to high-energy photons. A comparison between the simultaneous time profiles of HEPD-01 electron fluxes and photons from GRB190114C, GRB190305A, GRB190928A, GRB200826B, and GRB211211A has shown a remarkable similarity, in spite of the different energy ranges. The high-energy response, with peak sensitivity at about 2 MeV, and moderate effective area of the detector in the actual flight configuration explain why these five GRBs, characterized by a fluence above ∼3 × 10−5 erg cm−2 in the energy interval 300 keV–50 MeV, have been detected.

A spherical neutron long counter for 4[formula omitted] neutron detection in the energy range of 0.01 eV to 20 MeV

Neutron detection using a long counter is the most commonly used method for accurate neutron flux measurement. It is desirable to design a long counter with a flat energy response and a consistent angular response. This requires counters to have neutron-energy-independent efficiency over a wide range of energies and a very slight dependence on the direction of neutron incidence in the 4π space. In this work, we designed a spherical neutron long counter using the Monte Carlo method, with a model consisting of a polyethylene ball, built-in air rings, and boron carbide material. The internal air rings enhance the energy response of thermal neutrons, spherical polyethylene improves the energy response of fast neutrons, and boron carbide material solves the problem of high local neutron energy response. We analyzed the energy response, angular response, and detection efficiency of long counters using neutron sources such as Pu–Be and Am–Be. The results show that the neutron energy response is relatively flat in the energy region of 0.01 eV to 20 MeV, the angular response is consistent in 2π space, and the maximum relative angular response deviation in 4π space is no more than 16.5%. We focus on the applicability of long counters in complex neutron fields, such as scattered neutron fields, and provide a reference for their use of long counters in neutron detection.

ALD prepared silver nanowire/ZnO thin film for ultraviolet detectors

Ultraviolet (UV) detectors have played an important role in military communication, natural disaster warning, biomedical detection and other fields. In the ultraviolet region, ZnO has the advantages of a wide band gap, high exciton binding energy and intrinsic response band, which is an excellent semiconductor material for ultraviolet detectors. However, to improve the performance of ZnO-based UV detectors, it requires the control of their oxygen vacancy defects by keeping the free carrier concentration at a low level, which can be depleted to achieve the cutoff state of the detector. Therefore, it is necessary to modify the ZnO thin film material to reduce defects and improve crystallinity. In this paper, ZnO films with optical advantages nonpolar structure, AgNW/ZnO enhanced UV detectors and silver nanowires/ZnO (AgNW/ZnO) electrodes were prepared by atomic layer deposition (ALD) and heat treatment. The XPS analysis shows that the crystallinity and oxygen vacancy of ZnO films are improved after heat treatment at 600 ℃. The surface resistance of ZnO films reaches the level of MΩ per centimetre. In the comparison of the properties of the detectors after heat treatment at 500–800 ℃, the detector obtained the best comprehensive performance after heat treatment at 600 ℃. The light responsiveness (5 V, 365 nm) can reach 120.4 A/W, with a light-to-dark current ratio of 6686 times, and a light detection value of 3.4 × 1011 Jones. It is found that the number of deposition cycles has little effect on the transmittance of AgNW/ZnO electrodes in the visible range (380–780 nm), and AgNW/ZnO electrodes for 500 times have excellent thermal stability, which the square resistance is only increased by 1.9 times when heated at 400 ℃ for 180 min.

Crystal phase control and ignition properties of HNS/CL-20 composite microspheres prepared by microfluidics combined with emulsification techniques

Improved controllability and energy density of ignition agents are of great significance for the development of energetic composite materials. In this study, droplet microfluidics and emulsification techniques were combined to prepare HNS/CL-20 composite microspheres with polyglycidyl azide polymer (GAP) as the binder. The influence of binder content on the morphology of microspheres was investigated, and the microspheres were characterized and tested for particle size, crystal structure, thermal decomposition, dispersibility, mechanical sensitivity, combustion behavior and detonation performance. The results showed that microspheres prepared with a binder content of 3% had higher sphericity and particle size uniformity. The microspheres retained the crystal structure of both HNS and CL-20 (ε-type). Compared with raw HNS, the microspheres had higher apparent activation energy, better safety performance, and good dispersibility. The ignition experiments and detonation performance tests show that HNS/CL-20 composite microspheres have excellent ignition performance, obvious combustion flame, and significant energy release effects, which are expected to achieve high energy and high-speed response of the igniter, thus improving the ignition reliability in special environments or systems.

High-energy response activation for bistable energy harvester with variable damping control

High-energy response activation for bistable energy harvester with variable damping control

Merging technologies and supervised classification methods to quantify capture behavior on hook-and-line

Animal behavior varies in response to capture between/within species and fisheries, and its expression may contribute to incidental mortality when behaviors result in physiological ramifications that cannot be resolved. However, this relationship between capture behavior and animal health is poorly understood, and it remains a logistical challenge to evaluate behavior during capture. We describe an experimental technique that characterizes and quantifies capture behavior in hook-and-line fisheries. This technique includes (1) simultaneously monitoring the behavioral response to capture with accelerometers and cameras, (2) characterizing behavior from video footage and linking discrete behaviors to acceleration data, and (3) predicting behavior based solely on acceleration data using an ensemble of supervised classification methods. We captured oceanic whitetip sharks, Carcharhinus longimanus, with experimental (hook-and-line) gear to test these techniques (n = 38 capture events), with capture durations ranging from 4 to 68 min. In all, 145,589 tri-axial acceleration observations were collected across these events, including simultaneous video footage (six hours total) from 10 capture events. Three discrete capture behaviors were characterized: steady swimming, a high-energy response consisting of thrashing and burst swimming, and a loss of body orientation while hanging motionless from the gear. The latter two behaviors can lead to physiological stress if exhibited for prolonged periods. Our trained ensemble of supervised classification methods successfully predicted behaviors from acceleration data with up to 95.2% accuracy. This technique provides a better understanding of the behavioral response to hook-and-line capture and, if paired with health or fate assessments, can characterize the influence of behavior on mortality. Our technique also provides a method for predicting behavior based on acceleration data alone, which can be more feasible to collect across the spectrum of fishing conditions and practices within a fishery. Such information will assist in understanding how species respond to capture on hook-and-line gear and in the formulation of species- and fishery-specific strategies for mitigating mortality.

Fabrication and Characterization of Planar on-Chip Micro-Supercapacitors Based on Nitrogen and Oxygen Co-Doped Graphene Quantum Dots by Modified Liquid-Air Interface Self-Assembly Method

Planar micro-supercapacitors stand out among micro/nano energy storage components for their high power, high energy, long life and fast time response. In this paper, all-solid-state planar on-chip micro-supercapacitors with high power characteristics were prepared by modified liquid-air interface self-assembly method, photolithography and sputtering gold. The nitrogen and oxygen co-doped graphene quantum dots electrode films are continuous and uniform, and the surface contains a large number of nitrogen and oxygen chemical bonds and functional groups. The finger width of the supercapacitors is 50 μm, the gap width is 50 μm and a number of electrode fingers is 100. In terms of performance, the supercapacitors had a very short time constant (2.16 μs), high power density (15.80 μW cm−2) and excellent cycle stability (94.5% capacity retention after 10000 cycles).

Multiattribute analysis of channel architectural elements within the deepwater Taranaki Basin, 3D Romney data

The Taranaki Basin is located offshore west of North Island, New Zealand. Within the study area, deepwater channel systems are present as a result of plate boundary movement and clastic deposition during the Plio-Pleistocene. Multiattribute analysis revealed a few interesting features that we identified and interpreted. After refining the horizon of focus, we have concluded some interpretations as noise, whereas others were confirmed as geologic deposits. In one funny-looking thing (FLT 1), we interpreted high energy and high sweetness response along the northwestern portion of the main channel body as a sand-rich levee deposit and, in a second funny-looking thing (FLT 2), scalloping and elongate “finger-like” geometries as noise. The visualization and interpretation of these features through seismic attributes allow for optimized exploration, and therefore an opportunity for hydrocarbon extraction, within the Taranaki Basin. Geologic feature: Deep marine channel system: sandy channel fill to the northwest (FLT 1); interesting features in the center of the time slice (FLT 2) Seismic appearance: Chaotic, discontinuous reflectors with a high-energy response (FLT 1); chaotic high-variance features (FLT 2) Alternative interpretations: Overlapping sand-dominated channel (FLT 1); crevasse splays, fan lobes, distributary channels, ravines, and incisions (FLT 2) Age: Plio-Pleistocene Location: Taranaki Basin, western offshore North Island, New Zealand Seismic data: Provided by Anadarko Taranaki Company Analysis tool: A 3D reflection seismic, geometric, and physical seismic attributes

Experimental study of the adaptive gain feature for improved position-sensitive ion spectroscopy with Timepix2

In the present work, we study the Timepix2 pixels’ high energy response in the so-called adaptive gain mode. Therefore, Timepix2 with a 500 μm thick silicon sensor was irradiated with protons of energies in the range from 400 keV to 2 MeV and α-particles of 5.5 MeV from 241Am. A novel method was developed to determine the energy deposit in single pixels of particle imprints, which are spread out over a set of neighbor pixels (cluster). We show that each pixel is capable of measuring the deposited energy from 4 keV up to ∼3.2 MeV. Reconstructing the full energy content of the clusters, we found relative energy resolutions () better than 2.7% and better than 4% for proton and α-particle data, respectively. In a simple experiment with a 5.5 MeV α-particle source, we demonstrate that energy losses in thin (organic) specimen can be spatially resolved, mapping out sample thickness variations, with a resolution around 1–2 μm, across the sensor area. The inherent spatial resolution of the device was determined to be 350 nm in the best case.

Designing miniature x-ray optics for the SmallSat lunar science mission concept CubeX

Planetary remote-sensing instruments are often required to cover a relatively large field of view, ideally with a uniform angular resolution over the field, due to relatively large apparent sizes of planetary targets at close proximities. They also have to comply with relatively tight mass and volume constraints. For these reasons, planetary x-ray telescopes in the past were mainly collimation-based x-ray spectrometers without focusing optics. Recent advances in x-ray optics technology now enable compact focusing x-ray telescopes suitable for planetary science (e.g., BepiColombo). We present two design options for compact Wolter-I x-ray optics for a SmallSat lunar mission concept—the CubeSat X-ray telescope (CubeX). The primary objectives of CubeX are to map surface elemental abundances of selected lunar impact craters and to assess the feasibility of millisecond x-ray pulsar timing navigation in realistic deep space navigation environments. The Miniature X-ray Optics (MiXO) in CubeX utilizes electroformed NiCo alloy replication (ENR) technology, which provides many advantages over micro-pore optics (MPO) employed in BepiColombo. We carry out extensive ray traces over a grid of mirror parameters and explore a novel tapered shaped design of tightly nested shells, where both shell length and focal-plane offsets vary with shell diameter. One of the two configurations is optimized for large effective areas at low energies, while the other for lower mass and high-energy response. We compare their performances with those of conventional designs through the spatial resolution and effective area estimated by ray traces.

Toward Wideband Piezoelectric Harvesters Through Self-Powered Transitions to High-Energy Response

Abstract Convergence to low-energy responses arising from coexistence of multiple stable nodes is the main drawback of a nonlinear energy harvester preventing it from efficient wideband operation. A switching circuit with a boost-like topology has been proposed in this paper to overcome this substantial challenge. The circuit uses the energy harvested by the device to trigger it to jump from the low- to high-energy response. The performance of the proposed harvesting system when subjected to single harmonic excitations covering a wide range of frequencies is verified through both analytical and numerical investigations. Results indicate that by proper selection of timing parameters of the circuit including ON-time period of the switches together with the phase differences between the switching signals and the mechanical excitation, the applied electrical perturbation will be able to trigger the nonlinear resonating beam to jump from a low-energy response to the basin of attraction of the high-energy one within the whole frequency band in which a multivalued solution exists. Also, a probabilistic study is performed on a system with random phases of switching signals which shows that a successful switching from low- to high-energy response is achievable with a probability more than 80% by just controlling the ON-time period of the switch within the proper ranges with respect to the excitation frequency.

Toward self-powered nonlinear wideband vibration energy harvesting with high-energy response stabilization

This paper describes an effort to develop a nonlinear wideband vibration energy harvester with self-powered stabilization control of its high-energy response. In a Duffing-type nonlinear wideband energy harvester, a well-recognized difficulty of coexisting attractors arises so that the emergence of the response in the high-energy branch is not guaranteed because it depends on the initial conditions to which steady-state solutions the state is attracted. The response stabilization control technique introduces a negative resistance which returns the harvested power to the nonlinear resonator to destabilize the undesirable low-energy solution and make the high-energy solution globally stable. In this paper, the power balance of the response stabilization control under intermittent disturbances is first experimentally studied, and a charging circuit to self-power the negative impedance converter (NIC) in the control circuit is then developed. It is concluded that the energy consumed by the NIC can be retrieved by the energy harvesting in 100 seconds even in the worst case.

Simulation study of the dose and energy responses of FNTD personal neutron dosimetry

The objective of this work was to use the Geant4 toolkit to perform simulation studies on the personal dose response of fluorescent nuclear track detectors (FNTDs). The entire structure of the FNTD response can be designed, and the detector’s energy and dose responses can be optimized in a broad energy range (0.01 eV–20 MeV). In general, the detectors used 6LiF and CH2 converters that have high energy and high dose response at neutron energies lower than 10 eV and greater than 1 MeV, respectively. The method of least squares was used to optimize the dose response of H*(10) and the energy response corresponding to Rtotal. The values of the optimized response of H*(10) lie between 0.8 and 1.4, corresponding to the energy ranges 0.01 eV–70 keV and 4–14 MeV, respectively. This occupies nearly eight out of the nine orders of the total energy range. Even though the optimized response of Rtotal is constrained between 0.89 and 1.1 in the energy range of 0.01 eV–20 MeV, it is suitable for obtaining the broad neutron spectrum of fluence with good accuracy.

Development of neutron survey meter using prescila neutron probe

This paper presents the design and validation of a neutron survey meter. The meter consists of a PRESCILA neutron probe (with good sensitivity, directional response, gamma rejection, and enhanced high-energy response to 20 MeV) and an electrometer developed at Non-Destructive Evaluation center. The homogeneity response of the PRESCILA neutron probe was investigated as a function of distances from the 241Am - 9Be source in order to obtain the appropriate distance for accurate count-rate measurements using the neutron survey meter. A system consists of the PRESCILA neutron probe and the Ludlum Model 2326 electrometer was then used for measuring neutron ambient dose equivalent rates in the range from 50 cm to 200 cm with the step of 25 cm. The relationship between the count-rates and neutron dose equivalent rates (in the distance ranged from 50 to 200 cm) were deduced to validate the proper operation of the neutron survey meter.

A broadband energy harvester using leaf springs and stoppers with response stabilization control

This paper presents the design, fabrication and experimental verification of a broadband vibration energy harvester having a nonlinear oscillator using leaf springs and stoppers. In the conventional vibration energy harvester having a linear oscillator, there is a trade-off relationship between the magnitude of the resonance peak and the resonance band. Since the resonance band is expanded by using the nonlinear oscillator, the harvester can more efficiently generate electric energy in a wider frequency band. In this study, we designed and fabricated a nonlinear vibration energy harvester with leaf springs and stoppers, and verified the frequency response characteristics and the power generation performance of the proposed harvester by sinusoidal sweep tests with the input acceleration amplitude of 0.2 Grms. The overall resonance bandwidth was approximately 33 Hz, which was over 75 % of the linear natural frequency of 42 Hz. The response stabilization control successfully destabilized the coexisting low-energy solution, and activated only the high-energy response in the resonance band.

A new controlled superconducting magnetic energy storage for dynamic stabilization of distributed generation in islanding mode of operation

Summary According to IEEE std. 1547, islanding mode is “a condition in which a portion of an Electric Power System (EPS) is energized solely by one or more local EPSs through the associated Point of Common Coupling (PCC) while that portion is electrically separated from the rest of the area EPS”. Therefore, the dynamic instability due to islanding may result in power swing and finally loss of synchronism. Hence, many studies have been done for islanding detection and disconnection of distributed generation (DG) in an EPS. But, these conventional methods eventually lead to the disconnection of the DG units. To improve DG dynamic stability, superconducting magnetic energy storage (SMES) can be used effectively, because SMES have a high-energy density and fast response. This paper proposes a new method to damp the power swing after DG islanding and to maintain synchronism conditions based on SMES. Hence, the disconnection of the DG units is not required. Also, new controllers are developed for SMES including voltage source converter (VSC), and DC-DC chopper. The controller structures of VSC and DC-DC chopper are of PI and fuzzy logic-based type, respectively. Superconducting coil charging is controlled by the DC-DC chopper. SMES sizing is performed, based on power swing equations. Hereupon, dynamic load model is considered. Performance of the proposed method is evaluated by defining 12 scenarios such as strong and weak networks with load changing simulated in PSCAD. Simulation results show that the islanded DG stabilization (IDGS) method has good performance to maintain stability margin in a weak network.

Terahertz-infrared electrodynamics of single-wall carbon nanotube films

Broad-band (4–20 000 cm−1) spectra of real and imaginary conductance of a set of high-quality pristine and AuCl3-doped single-walled carbon nanotube (SWCNT) films with different transparency are systematically measured. It is shown that while the high-energy (≥1 eV) response is determined by well-known interband transitions, the lower-energy electrodynamic properties of the films are fully dominated by unbound charge carriers. Their main spectral effect is seen as the free-carrier Drude-type contribution. Partial localization of these carriers leads to a weak plasmon resonance around 100 cm−1. At the lowest frequencies, below 10 cm−1, a gap-like feature is detected whose origin is associated with the energy barrier experienced by the carriers at the intersections between SWCNTs. It is assumed that these three mechanisms are universal and determine the low-frequency terahertz-infrared electrodynamics of SWCNT wafer-scale films.

Development of high resolution dual-energy KBA microscope with large field of view for RT-instability diagnostics at SG-III facility.

High resolution X-ray diagnosis is a significant method for obtaining ablation-front and trajectory measurements targeting Rayleigh-Taylor (RT)-instability growth in initial confinement fusion (ICF) experiments. In this paper, a novel Kirkpatrick-Baez-type structure, as a kind of essential X-ray micro-imaging apparatus, has been developed that realizes a large field of view (FOV) and images with high resolution and energy response. Zoned multilayer coating technology is applied to the Kirkpatrick-Baez mirrors to transmit two specific quasi-monochromatic light through the same mirror and enables a compact dual-channel structure. This microscope has been assembled in the laboratory and later implemented at the Chinese SG-III laser facility. The characterization results show that this imaging system can achieve a good spatial resolution of 5 µm in a large FOV of 500 µm, while maintaining a strong monochromatic performance with bandwidth of 0.5 keV at 2.5 keV and 4.3 keV respectively.