Low-power Radiation Research Articles

A robust, low power and high speed radiation hardened 12T SRAM cell for space applications

High-energy particles found in space environment can cause single event upsets (SEUs). The severe environments found in space are too harsh for conventional 6T static random-access memory (SRAM) cell as its data get altered when a radiation particle strikes a susceptible place of the cell. Therefore, creating an SRAM that can withstand these demanding space circumstances is essential. This paper proposes a High Speed Radiation Hardened 12T (HSRH12T) SRAM cell which is suitable for low power applications and mitigates the effect of both SEU and multi-bit soft errors. All of the HSRH12T sensitive nodes are capable of recovering their data, even in the event that a radiation impact flips the node values. The HSRH12T demonstrates up to 1.6×/7.88×/1.31×/23.37× reduction in read delay (TRA), write delay (TWA), leakage and dynamic power consumption, respectively. The proposed cell exhibits up to 1.64× greater critical charge compared to the other considered cells.

Modified Martin-Puplett interferometer for magneto-optical Kerr effect measurements at sub-THz frequencies.

We present a magneto-optical Kerr effect (MOKE) spectrometer based on a modified Martin-Puplett interferometer, utilizing continuous wave sub-THz low-power radiation in a broad frequency range. This spectrometer is capable of measuring the frequency dependence of the MOKE response function, both the Kerr rotation and ellipticity, simultaneously, with accuracy limited by a sub-milliradian threshold, without the need for a reference measurement. The instrument's versatility allows it to be coupled to a cryostat with optical windows, enabling studies of a variety of quantum materials such as unconventional superconductors, two-dimensional electron gas systems, quantum magnets, and other systems showing optical Hall response at sub-Kelvin temperatures and in high magnetic fields. We demonstrate the functionality of the MOKE spectrometer using an undoped InSb wafer as a test sample.

An Enhanced LPRAFF with Tri-State Inverter Embedded Non-Clock Gating via the CT-GWO Algorithm

Since a long time ago, it has been understood how radiation affects digital circuits, particularly those using the Complementary Metal Oxide Semiconductor (CMOS) model. Total Ionisation Dose (TID) and Single Event Effects (SEE) are the two most significant radiation effects. Depending on the gate input count, the complexity of the circuit will rise, which will worsen the radiation and raise the cumulative dose levels. The incremental dose level affects the circuit parameter failure, which affects how well the logic design functions. Many authors concentrate on minimising the effects of radiation while preventing function loss, but these extra efforts use excess energy. To improve the efficiency of the Low Power Radiation Aware (LPRA) circuit, this paper introduces optimisation concepts in a Flip Flop (FF) architecture named Chaos Theory-based Grey Wolf Optimised FF (CT-GWOFF). First, compute each component's radiation response using a physics-based modelling strategy. To minimise undesirable latches and disable the inverter chain when the input data remain constant, a tri-state inverter, incorporating a non-clocked gating mechanism, is provided. This prevents repeated transitions of delayed clock signals. Moreover, the proposed model is implemented in FFs for simulation purposes, making it more cognizant of radiation effects and power consumption. Using the HSPICE tool, the performance of the suggested circuit design is evaluated at the 16 nm CMOS Predictive Technology Model (PTM).

Observation of THz surface waves escaping from metal gratings through a dielectric substrate.

Extensive research has been conducted on generating THz waves using Smith-Purcell radiation, yet a portion of the electron bunch's interaction energy with the gratings is confined to the metal gratings' surface, leading to a low THz radiation power. This paper experimentally demonstrates that metal gratings with a dielectric substrate can emit the resonant modes in surface waves when excited by relativistic femtosecond electron bunches. The observed spectra of the resonant THz waves align well with the theoretical estimations derived from the configuration's dispersion relation and 3D simulations. In comparison to traditional Smith-Purcell radiation generated by the grating, these resonant THz waves exhibit significantly higher intensity and improved orientation. Additionally, we investigated the radiation characteristics of the resonant THz waves, including radiation angle, beam-grating distance, beam energy, and bunch length. This innovative approach presents a novel method for generating high-power coherent terahertz radiation.

Long-term field studies of a distributed network of sensors for environmental radiological monitoring

The W-MON project goal is to establish an automatic control mechanism of the presence of radioactive material in conventional waste containers at CERN using a distributed network of interconnected low-power radiation sensors. This network facilitates continuous data recording, transfer and storage in a database while allowing online and offline data analysis, in addition to alarm triggering. Data transmission, processing and evaluation is achieved by a centralized IoT end-to-end data architecture that has been developed for real-time monitoring and visualization of the radiation levels in waste containers. In this paper the results of field tests of the W-MON system described in two previous papers are presented for three different types of sensors. Estimation of failure detection probability, long-term stability tests and sensitivity studies carried out using radioactive samples of various activities placed in standard waste containers are described. A comparison between the manual monitoring procedure currently used at CERN and the W-MON system is discussed in detail.

Influence of laser marking parameters on data matrix code quality on polybutylene terephthalate/glass fiber composite surface using microscopy and spectroscopy techniques

<abstract> <p>Laser marking on polymer composite surfaces can be difficult to read and cause readability problems for electronic decoding equipment on production lines due to poor interaction between the laser and the fibers used to reinforce these materials. This problem can be solved with the right choice of marking parameters, resulting in savings for companies by avoiding production problems such as rejection, scrap and customer complaints. The present work uses the polybutylene terephthalate/glass fiber (PBT/GF) composite used in the manufacture of instrument panels for motorcycles. The tests were carried out with different laser marking parameters using a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Subsequently, the laser-marked data matrix codes (DMC) were analyzed using a microscope verifier to evaluate the quality according to the ISO/IEC 29158:2020 standard. A detailed analysis of these surfaces was also carried out to observe some physical and chemical changes using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The optical analysis showed that lower radiation power and pulse frequency and higher marking speed corresponded to weaker laser marking and therefore poorer DMC code quality, which was confirmed by the SEM. EDS showed that the laser marking process did not cause the chemical changes on the sample surface.</p> </abstract>

Design and Performance Analysis of New Coupling Magnetic Core Structure for Dynamic Wireless Charging System of Electric Vehicle

Aiming at the problems of high cost, low efficiency, low power, and high electromagnetic radiation in the dynamic wireless charging system for electric vehicles (EVs), the cover‐like coupling structure and the return‐like coupling structure are designed, and the unique concave structure has excellent engineering practicability. Using Ansoft software for simulation and analysis, the newly proposed two coupling structures have significantly improved the induced voltage and electromagnetic induction strength at the pickup end compared with other commonly used coupling core structures. According to the advantages of practical applications, the application of its composite core structure for simulation and analysis proves that the cover‐like structure of the magnetic field strength at the pickup end not only enhances the magnetic field strength on the coil but also has a good magnetic field shielding effect. The lateral displacement of the EV is kept within the range of 10 cm, the coupling distance is 0–5 cm, the charging is stable, and the transmission efficiency is high. Finally, a dynamic wireless charging experimental platform for small EVs is constructed, which verifies that the new coupling core structure can significantly improve the transmission power and efficiency of the charging system and significantly reduce the economic cost.

Design and research of wireless optical power meter based on IoT big data and physical quantity

In response to the problems of low accuracy, high radiation, and high power consumption in industrial UV power detection, the author proposes a design scheme based on a low-power microcontroller MSP430 as the core controller, two UV photoelectric sensors as detectors, and wireless LoRa as the data transmission method. This scheme adopts dual sensors and achieves photoelectric conversion and ambient light filtering through a subtractive amplification circuit. It also uses high-precision programmable AD acquisition chips to achieve controllable amplification of the signal and convert analog signals into digital quantities for transmission to the main controller MSP430. The improved sliding average filtering method is used to perform digital filtering on the collected data and calculate the corresponding power value, data is transmitted to the upper computer for real-time display through wireless Lora. Research and experiments have shown that the dual sensors have a good agreement with the standard values. The difference between the measured values after digital filtering and the standard values is small, and the linearity of digital filtering is good. It can be seen from the two figures that the higher the power value, the higher the lighting temperature. It has been proven that the entire system operates stably, with high accuracy, low power consumption, and can remotely and real-time detect changes in ultraviolet light power. It can be widely used in the field of industrial ultraviolet light detection.

Fast fabrication of mesostructured MCM-41-type nanoparticles by microwave-induced synthesis

This work reports the synthesis of mesoporous MCM-41 nanoparticles by applying microwave radiation (MWR) in the range of 400–1000 W. Silica nanoparticles were produced at short time (10 min) and low power radiation (400 W) which showed large surface area (SBET ∼1000 m2g-1) and a suitable chemical surface composition. Both, scanning and transmission electron microscopies (SEM and TEM) revealed that the mesoporous silica had a nanometric size close to 100 nm with a predominant spherical morphology. Also, it was found that the particles were smaller and agglomerated at higher microwave radiation power (>600 W) and longer heating time (>10 min). On the other hand, low microwave radiation power (400 W) was sufficient to obtain MCM-41 with high surface area (1182 m2g-1) keeping the same particle size. Under MWR synthesis, pore diameters slightly expanded up to ∼4.00 nm which are larger for those obtained by the hydrothermal method (∼2.0 nm). According to the FTIR results, the surface of the sample labeled as MCM400W10 exhibited a number of free silanol groups (αΟΗ) of ∼4.08 per nm2 which could improve their surface modification for being used in diverse biomedical applications including drug delivery.

A Low-Power Radiation Detection SoC With Neural Network Accelerator for Radioisotope Identification

This work presents a low-power radiation detection and radioisotope identification System on Chip (SoC) featuring mixed-signal sensory electronics and on-chip neural network (NN) acceleration hardware. The chip electronics form a multichannel analyzer (MCA) to process the signal from an external radiation detector and produce an energy spectrum of the incoming radiation detections. The NN hardware accelerator then provides a novel means of using the spectrum to perform radioisotope identification. The chip is, thus, able to determine which radioisotopes are present in the radiation source. An on-chip 32-bit microcontroller (MCU) configures the analog front-end (AFE) electronics, oversees the NN hardware, and provides an interface to retrieve the histogram and NN data. The chip is fabricated on a 65-nm CMOS technology and consumes 8.8 mW while acquiring a histogram. In the tested configuration, the radioisotope identification NN takes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$694~\mu \text{s}$ </tex-math></inline-formula> to execute, consuming <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.94~\mu \text{J}$ </tex-math></inline-formula> of energy and using 13.8 kB of RAM in the process. After training, the system correctly identified which isotopes were present in all histograms in a test set composed of combinations of four trained isotopes.

Ultra-Broadband NPE-Based Femtosecond Fiber Laser

A dissipative soliton mode-locked Yb-doped fiber laser is investigated experimentally and numerically from the point of view of generating ultra-broadband ultrashort pulses. An energy up to 2.2 nJ and a spectral bandwidth over 60 nm (at the −10 dB level) were obtained experimentally without dispersion compensation in the cavity. Almost a 100-fold compression coefficient has been achieved, so the resulting pulse duration was 149 fs. The numerical simulation has shown that a further scaling up to 3.5 nJ and a 100 nm spectral bandwidth is possible by reducing the low power transmission coefficient of the NPE-based SAM and increasing the amplification. At the same time, the tolerance of the SAM to a low power radiation is responsible for the transition to a multi-pulse operation regime.

Numerical study on THz radiation of two-dimensional plasmon resonance of GaN HEMT array

The GaN high electron mobility transistor (HEMT) has been considered as a potential terahertz (THz) radiation source, yet the low radiation power level restricts their applications. The HEMT array is thought to improve the coupling efficiency between two-dimensional (2D) plasmons and THz radiation. In this work, we investigate the plasma oscillation, electromagnetic radiation, and the integration characteristics of GaN HEMT targeting at a high THz radiation power source. The quantitative radiation power and directivity are obtained for integrated GaN HEMT array with different array periods and element numbers. With the same initial plasma oscillation phase among the HEMT units, the radiation power of the two-element HEMT array can achieve 4 times as the single HEMT radiation power when the array period is shorter than 1/8 electromagnetic wavelength. In addition, the radiation power of the HEMT array varies almost linearly with the element number, the smaller array period can lead to the greater radiation power. It shows that increasing the array period could narrow the main radiated lobe width while weaken the radiation power. Increasing the element number can improve both the radiation directivity and power. We also synchronize the plasma wave phases in the HEMT array by adopting an external Gaussian plane wave with central frequency the same as the plasmon resonant frequency, which solves the problem of the radiation power reduction caused by the asynchronous plasma oscillation phases among the elements. The study of the radiation power amplification of the one-dimensional (1D) GaN HEMT array provides useful guidance for the research of compact high-power solid-state terahertz sources.

Interfacial Flows and Interfacial Shape Modulation Controlled by the Thermal Action of Light Energy

The review covers the research on thermocapillary convection caused by the thermal action of laser radiation in single-layer and bilayer liquid systems of capillary thickness. The advantages of using optical radiation are the instantaneous delivery of thermal energy to a place on demand (a bulk phase, interfaces); low radiation power required; concentrating heat flux on a spot of a few micrometers; the production of arbitrary spatial distributions of radiation intensity; and, as a result, corresponding thermal fields at a liquid interface and their fast reconfiguration. Thermocapillary stresses at the liquid interfaces lead to the transfer of the liquid and a change in the shape of the interface, in accordance with the distribution of the light-induced thermal field. Studies concerned with the methods of non-destructive testing of liquid media and solids, which are based on a photothermocapillary signal emitted by a laser-induced concave deformation of a thin layer, are considered. Features of thermocapillary deformation of a liquid–air interface caused by local heating of thin and thick (exceeding the capillary length) layers are demonstrated. A part of the review addresses the results of the study of thermocapillary rupture of films in the heating zone and the application of this effect in semiconductor electronics and high-resolution lithography. The works on the light-induced thermocapillary effect in bilayer (multilayer) liquid systems are analyzed, including early works on image recording liquid layer systems, liquid IR transducers, and nonlinear optical media.

Development of methods and models to improve the noise immunity of wireless communication channels

It has been shown that existing methods and models for improving the noise immunity of communication channels are not capable of meeting requirements for the quality of information in mobile infocommunication systems. In addition, the compromised quality of information fails to protect it and provide the speed of information transmission and density of access channels. It has been proven that reducing the level of electromagnetic radiation is the main method of ensuring noise immunity in wireless mobile communication systems of infocommunication systems. Therefore, one way to ensure the stable interference-free operation is to reduce the level of the information signal at the receiver input to the noise level when the signal/noise ratio is equal to one. This paper reports the results of studying methods and models with correlation reception of ultra-wideband signals. It is proved that according to the level of potential noise immunity, the best indicators are shown by the model of encoding an ultra-wideband information signal by phase manipulation, followed by the coding model with opposite chips, and the code-time manipulation model. It is shown that with a large base of the signal B&gt;300 when the intensity of the received signals is below the level of interference, reliable transmission of information is carried out with a probability of error of less than 10-6. This proves that the use of ultra-wide signal technology allows for wireless hidden transmission of information with low radiation power and a low probability of error. Thus, at a speed of 12 Mb/s, it is possible to chain the transmission of information with a probability of error less than 10-6 if there is a large signal base used, B =500‒1000.

Болевой синдром при варикозной болезни под влиянием эндовенозной лазерной абляции

Параллельное с эндовазальной (эндовенозной) лазерной абляцией проведение кроссэктомии повышает аналгетическую эффективность оперативного лечения варикозной болезни нижних конечностей на начальных этапах наблюдения за больными (через 1 неделю). Интегральная динамика физико-химических показателей адсорбционно-реологических свойств венозной крови у больных с кроссэктомией и без таковой не отличается, причем независимо от выполненной кроссэктомии к первому месяцу после лазерной эндовенозной коагуляции происходит нормализация параметров поверхностной вязкости и упругости, модуля вязкоэластичности, улучшение значений объемной вязкости и поверх­ностной релаксации. Маломощная эндовенозная лазерная абляция с излучением 10 ватт и менее через 4 недели после операции превосходит по аналгетической эффективности выполненное хирургическое лечение варикозной болезни нижних конечностей с излучением в 15 ватт, при этом способствует уменьшению релаксационных свойств сыворотки венозной крови, а интегральные параметры адсорбционно-реологических свойств сыворотки зависят от влияния энергии лазера на длину и площадь просвета стриппинга.

Nonlinear optical properties of single-walled carbon nanotubes/water dispersed media exposed to laser radiation with nano- and femtosecond pulse durations

The constant increase in the power of laser systems and the growth of potential fields for the application of lasers make the problem of protecting sensitive elements of electro-optical systems and visual organs from high-intensity radiation an urgent issue. Modern systems are capable of generating laser radiation in a wide range of wavelengths, durations, and pulse repetition rates. High-quality protection requires the use of a universal limiter capable of attenuating laser radiation, not causing colour distortion, and having a high transmission value when exposed to low-power radiation. For this, dispersed media based on carbon nanotubes with unique physicochemical properties can be used. Such media have constant valuesof their absorption coefficient and refractive index when exposed to low-intensity laser radiation and change their properties only when the threshold value is reached.The aim of this work was the study of the nonlinear optical properties of an aqueous dispersion of single-walled carbon nanotubes exposed to nano- and femtosecond radiation. For the characterization of the studied medium, Z-scan and fixed sample location experiments were used. The optical parameters were calculated using a threshold model based on the radiation transfer equation.As a result of the experiments, it was shown that the aqueous dispersion of single-walled carbon nanotubes is capable of limiting radiation with wavelengths from the visible and near-IR ranges: nano- (532, 1064 nm) and femtosecond (810 nm). A description of nonlinear optical effects was proposed for when a medium is exposed to radiation with a nanosecond duration due to reverse saturable absorption and two-photon absorption. When the sample exposed for a femtosecond duration the main limiting effect is spatial self-phase modulation. The calculated optical parameters can be used to describe the behaviour of dispersions of carbon nanotubes when exposed to radiation with different intensities. The demonstrated effects allow us to conclude that it is promising to use the investigated media as limiters of high-intensity laser radiationin optical systems to protect light-sensitive elements.

On the Achievable Rate and Capacity for a Sample-Based Practical Photon-Counting Receiver

We investigate the achievable rate and capacity of a non-perfect photon-counting receiver. For the case of long symbol duration, the achievable rate under on-off keying modulation is investigated based on Kullback-Leibler (KL) divergence and Chernoff $\alpha$-divergence. We prove the tightness of the derived bounds for large peak power with zero background radiation with exponential convergence rate, and for low peak power of order two convergence rate. For large peak power with fixed background radiation and low background radiation with fixed peak power, the proposed bound gap is a small positive value for low background radiation and large peak power, respectively. Moreover, we propose an approximation on the achievable rate in the low background radiation and long symbol duration regime, which is more accurate compared with the derived upper and lower bounds in the medium signal to noise ratio (SNR) regime. For the symbol duration that can be sufficiently small, the capacity and the optimal duty cycle are is investigated. We show that the capacity approaches that of continuous Poisson capacity as $T_s=\tau\to0$. The asymptotic capacity is analyzed for low and large peak power. Compared with the continuous Poisson capacity, the capacity of a non-perfect receiver is almost lossless and loss with attenuation for low peak power given zero background radiation and nonzero background radiation, respectively. For large peak power, the capacity with a non-perfect receiver converges, while that of continuous Poisson capacity channel linearly increases. The above theoretical results are extensively validated by numerical results.

Lightweight SiPM-based CeBr3 gamma-ray spectrometer for radiation-monitoring systems of small unmanned aerial vehicles

The radiation-monitoring systems of miniaturized unmanned aerial vehicles (UAVs) have wide-ranging applications. However, the load capacity and flight time of radiation-monitoring systems of UAVs are limited. Thus, a lightweight and low-power radiation monitoring load is significant to develop. Herein, a lightweight CeBr3 gamma-ray spectrometer based on Silicon photomultiplier (SiPM) was developed for small-UAV radiation-monitoring systems. Experiments were conducted to test the performance of the spectrometer. Excellent linearity and high energy resolution were achieved. Compared with the traditional CeBr3 scintillator gamma-ray spectrometer, the volume, mass, and power consumption of the spectrometer decreased by 73%, 55%, and 38%, respectively. Carrying the spectrometer developed in this paper can increase the compactness and flight time of small-UAV radiation-monitoring systems.

Comparison between Up-Conversion Detection in Glow-Discharge Detectors and the Schottky Diode for MMW/THz High-Power Single Pulse

Generally, glow-discharge detectors (GDD), acting on miniature neon indicator lamps, and Schottky diode detectors serve as efficient, fast, and room-temperature millimeter wave (MMW)/THz detectors. Previous studies on GDD implemented a repetition of terahertz sources, and low-power radiation, and showed good results in terms of detection, responsivity, and noise-equivalent power. This paper presents a comparison between a detector based on a GDD lamp and a Schottky diode detector for the detection of a high-power single pulse. With this comparison, we touch upon two GDD detection methods, the visual light emitting from the GDD and the electrical current of the GDD detector. Results showed better response time and better sensitivity for the GDD detection method compared to with the Schottky diode.

Effect of low power lasers on prokaryotic and eukaryotic cells under different stress condition: a review of the literature.

Radiations emitted by low power radiation sources have been applied for therapeutic proposals due to their capacity of inactivating bacteria and cancer cells in photodynamic therapy and stimulating tissue cells in photobiomodulation. Exposure to these radiations could increase cell proliferation in bacterial cultures under stressful conditions. Cells in infected or not infected tissue injuries are also under stressful conditions and photobiomodulation-induced regenerative effect on tissue injuries could be related to effects on stressed cells. The understanding of the effects on cells under stressful conditions could render therapies based on photobiomodulation more efficient as well as expand them. Thus, the objective of this review was to update the studies reporting photobiomodulation on prokaryotic and eukaryotic cells under stress conditions. Exposure to radiations emitted by low power radiation sources could induce adaptive responses enabling cells to survive in stressful conditions, such as those experienced by bacteria in their host and by eukaryotic cells in injured tissues. Adaptive responses could be the basis for clinical photobiomodulation applications, either considering their contraindication for treatment of infected injuries or indication for treatment of injuries, inflammatory process resolution, or tissue regeneration.