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Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes/issues, but are citable by Digital Object Identifier (DOI).
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, Available online , doi: 10.11884/HPLPB202537.250247
Abstract:
Background Purpose Methods Results Conclusions
The investigation of radioactive source terms serves as a critical basis for formulating reactor decommissioning plans, estimating costs and schedules, and ensuring adequate radiation protection and emergency preparedness.
During neutron irradiation, reactor components undergo neutron activation reactions that generate significant quantities of radionuclides. The decay photons emitted by these nuclides constitute the primary source of radiation exposure for personnel during reactor decommissioning.
A combined approach using Monte Carlo particle transport programs (cosRMC, MCNP) and activation calculation programs (DEPTH, ALARA) was employed to calculate the nuclide atom density, activity, and radiation dose rates for key components after a specified operational period.
Comparing results from the two activation programs shows relative deviations within acceptable limits.
The comparison demonstrates the reliability and accuracy of cosRMC’s activation calculations and dose rate assessment capabilities for reactor decommissioning analysis.
, Available online , doi: 10.11884/HPLPB202537.250085
Abstract:
Background Purpose Methods Results Conclusions
Transient intense electromagnetic pulses, characterized by extremely high peak field strength and broad frequency domain distribution, pose severe electromagnetic safety threats to electronic systems. Their accurate measurement is crucial for evaluating radiation source performance and the effectiveness of protection measures. However, ground-reflected waves often cause significant waveform distortion in far-field measurements. Existing narrow-spectrum suppression methods fail due to bandwidth limitations, while environmental adjustment approaches are impractical in complex scenarios, and traditional array beamforming techniques are restricted by signal correlation requirements.
To address the waveform distortion caused by ground-reflected waves in far-field measurements of transient intense electromagnetic pulses, this study proposes a monopole array-based waveform recovery algorithm. It aims to eliminate ground scattering interference and accurately extract direct waves, providing support for related measurements and evaluations.
The principle of direct wave extraction based on monopole array was derived in both frequency and time domains. Potential error sources and corresponding optimization schemes were analyzed. A measurement system was built under ground reflection conditions for experimental tests, and the performance of different algorithms was compared.
Experimental results show that the direct waves extracted by the proposed algorithm match the reference direct waves well, with amplitude error within 0.2 dB and main waveform fidelity coefficient greater than 0.99. The time-domain algorithm is more concise and less affected by interference, while the frequency-domain algorithm enables direct wave recovery with a single system, making it more cost-effective. Compared with traditional technologies, the algorithm expands the applicable frequency band and significantly reduces amplitude calculation error.
The proposed waveform recovery algorithm can effectively suppress ground scattering effects and accurately extract direct waves. It provides reliable support for parameter separation in transient pulse measurements and state evaluation of radiation systems.
, Available online , doi: 10.11884/HPLPB202537.250120
Abstract:
Background Purpose Methods Results Conclusions
Unmanned aerial vehicles (UAVs), representing advanced combat capabilities in new domains, have become essential weaponry in modern warfare. The proliferation of frequency-dependent equipment and rapid advancements in counter-UAV technologies have resulted in increasingly complex electromagnetic environments. High-power microwave (HPM) radiation, characterized by high power, tunable carrier frequency, and complex coupling effects, can effectively jam or damage UAV systems. Datalinks, acting as the UAV’s ‘brain’, are particularly vulnerable to HPM interference. Consequently, research into HPM coupling mechanisms and protection methods for UAV datalink is vital for enhancing UAV resilience.
This study investigates the coupling laws and protection methods of HPM radiation on the RF front-end of UAV datalinks.
Models of the datalink antenna and RF front-end PCB were developed using Computer Simulation Technology (CST) software. The antenna was irradiated with HPM pulses with variations in carrier frequency, pulse width, polarization direction, and rise time. The coupled voltage waveforms at the antenna output ports were analyzed. These voltages were injected into the receiver circuit model to determine the coupled voltage at the pins of the RF chip (Si24R1), thus simulating the complete HPM field-to-circuit coupling process. A 2.45 GHz PIN limiter was implemented for electromagnetic protection.
(1) The amplitude of the coupled voltage at the Si24R1 RF chip pins exhibited spiking behavior at high carrier frequencies. (2) Coupled voltage decreased significantly with increasing polarization angle. (3) Variations in pulse width and rise time had minimal effect on coupled voltage amplitude. (4) The PIN limiter significantly reduced the coupled voltages while maintaining signal reception quality, enhancing the datalink’s electromagnetic protection.
This work quantifies HPM coupling laws on RF front-end circuits under varying parameters. Implementing PIN limiter on the RF front-end significantly attenuates electromagnetic interference, providing a validated reference for UAV electromagnetic protection.
, Available online , doi: 10.11884/HPLPB202537.250152
Abstract:
Background Purpose Methods Results Conclusions
High Power Microwave (HPM) can destroy key components of communication systems through front-door coupling, resulting in system performance degradation or failure. For receivers with a single RF channel, the degree of system performance degradation can generally be evaluated using the effect results at the device level.
However, for phased array communication systems, the assessment of the system-level damage effect of HPM is a challenge. This is because there are numerous RF channels in the system, and the damage to each channel is inconsistent, making it difficult to apply the effect results at the device level to evaluate the system performance.
To verify the asymmetric damage effect of HPM on phased array communication systems and assess the impact of such asymmetric damage on system performance, this paper based on theoretical analysis, established a semi-physical simulation experiment and system-level irradiation experiment method, and conducted research on the asymmetric damage effect of typical phased array communication systems. The study investigated the additional impact of amplitude and phase inconsistency on system performance and carried out system-level verification experiments.
The results show that when the phased array communication system is damaged by HPM, asymmetric damage occurs between channels, affecting the synthesis of the phased array antenna beam, and further deteriorating the system performance.
Moreover, the greater the amplitude and phase inconsistency, especially the greater the phase inconsistency, the greater the additional loss in system performance.
, Available online , doi: 10.11884/HPLPB202537.250073
Abstract:
Background Purpose Method Result Conclusion
Radio frequency (RF) front-end components are among the most vulnerable elements in integrated circuit systems when exposed to intense electromagnetic environments. Investigating their degradation mechanisms and failure thresholds is therefore critical for identifying system weak points and devising effective protection and reinforcement strategies. However, existing high power microwave (HPM) injection tests rely on manual operation, lack standardized procedures and deliver limited repeatability.
In order to achieve precise and efficient evaluation of device degradation and failure thresholds and to establish standardized test methods and assessment procedures.
This work developed a high power microwave (HPM) automatic measurement platform grounded in the interaction mechanism between HPM and devices, and designed two testing protocols—single pulse excitation for electrical stress characterization and continuous pulse excitation for thermal failure evaluation.
A commercial low noise amplifier (LNA) served as the test device; synchronous measurements of time domain response, frequency domain characteristics and operating current, combined with pre/post test parameter comparison, pinpointed damage thresholds. Furthermore, we conducted a comprehensive evaluation of first, second, and third damage events, correlating cumulative damage effects with key device parameters through microphysical analysis to elucidate the dominant failure mechanisms.
The proposed measurement system and evaluation methodology offer a robust framework for reliability assessment of semiconductor devices in high power electromagnetic environments and provide essential experimental support for damage resilience analysis and optimized device design.
, Available online , doi: 10.11884/HPLPB202537.250143
Abstract:
Background Purpose Methods Results Conclusions
Precision-guided ammunition for electromagnetic railguns is gradually becoming a key area of competition among nations, which imposes new requirements on fuzes for electromagnetic railgun ammunition. Modern fuzes contain a large number of electronic components, and during the launch of electromagnetic railgun projectiles, the fuze is exposed to strong magnetic fields. These fields can interfere with the fuze's electronic components, leading to malfunctions or even damage. As a result, most mature electromagnetic railguns currently use kinetic energy projectiles or mechanical fuzes.
A reasonable arrangement of the fuze circuit module can reduce the structural thickness and weight of the electromagnetic shielding shell for the fuze circuit, while effectively ensuring the performance of the fuze circuit.
In this paper, a quasi-steady-state simulation model of the electromagnetic railgun is established. The electromagnetic induction performance of the circuit module under two different arrangement schemes is calculated and analyzed. The responses such as the magnetic field distribution, induced current, electromagnetic volume force density, and induced electromotive force on the fuze circuit module are obtained respectively.
When the fuze circuit module is arranged parallel to the projectile axis, although the overall magnetic field strength is greater than when it is arranged perpendicular to the projectile axis, the peak magnetic field strength in the perpendicular arrangement covers an entire surface of the circuit board, whereas in the parallel arrangement, the peak magnetic field strength is only at the edge of the circuit module’s end. When the fuze circuit module is arranged parallel to the projectile axis, the induced eddy current, electromagnetic volume force density, and induced electromotive force are all significantly smaller than those in the perpendicular arrangement.
For the fuze circuit module of electromagnetic railgun ammunition, arranging it parallel to the projectile axis can more effectively reduce the impact of the electromagnetic field during launch. Additionally, sensitive components should be avoided being placed at the ends and edges of the circuit module. This can greatly reduce the structural size, thickness and, weight of the shell for electromagnetic shielding of the fuze circuit components, so as to optimize the overall structure of the fuze and reduce the total weight of the fuze.
, Available online , doi: 10.11884/HPLPB202537.250118
Abstract:
Background Purpose Methods Results Conclusions
Unmanned aerial vehicle (UAV) data links operating in battlefield environments are highly susceptible to electromagnetic interference (EMI), frequently causing frame synchronization failures. direct sequence spread spectrum (DSSS) systems, while offering inherent interference resistance, remain vulnerable to intentional EMI attacks through front-door coupling pathways.
This study aims to establish loss-of-lock threshold models for DSSS-based UAV data links under two critical interference scenarios: in-band single-source single-tone and dual-source dual-tone EMI. The research further seeks to experimentally validate these models.
Through rigorous EMI mechanism analysis with emphasis on front-door coupling effects, the theoretical threshold models were developed for both interference scenarios. Test validation employed EMI injection testing on an operational UAV data link platform. Controlled variables included working signal power, interference frequencies, and interference power. The interference thresholds were obtained from the tests.
The test loss-of-lock thresholds demonstrated strong alignment with theoretical predictions across both interference scenarios. For single-source interference, the thresholds exhibited positive correlation with working signal power, and the absolute value of the frequency offset. Under dual-source interference, the thresholds of interference 1 showed inverse correlation with the power of interference 2.
The validated threshold models provide a theoretical foundation for EMI sensitivity assessment and test design in UAV data link systems. Key findings indicate: (1) The closer the interference frequency is to the carrier frequency of the working signal, the worse the anti-interference ability of the data link is. (2) Increasing the power of the working signal can improve the anti-interference ability of the data link. (3) Front-door coupling is an important way for EMI to enter the receiver in tactical scenarios. These findings could provide optimized EMI protection for the next generation of UAV data links.
, Available online , doi: 10.11884/HPLPB202537.250076
Abstract:
Background Purpose Methods Results Conclusions
Electromagnetic (EM) emissions from electronic devices can inadvertently carry sensitive information, posing significant threats to information security. EM fingerprinting techniques have become vital for security inspection and leakage source localization, yet existing approaches often suffer from poor adaptability across sampling rates and insufficient extraction of high-frequency features.
This study aims to develop a robust EM fingerprint recognition method that maintains high accuracy across different sampling rates while effectively capturing high-frequency characteristics, thereby improving security detection and adaptability in practical scenarios.
We propose an enhanced neural network architecture, termed ELEC-TDNN, which integrates a channel attention mechanism with multi-scale temporal modeling capabilities. A local signal enhancement layer is introduced to improve the representation of subtle EM features. Experiments were conducted on a self-constructed dual-sampling-rate USB device EM emission dataset (1.25 GHz and 500 MHz) to evaluate performance. The evaluation used equal error rate (EER) as the primary metric to measure recognition accuracy under varying frequency conditions.
The proposed ELEC-TDNN achieved superior adaptability and accuracy compared with conventional methods. At 500 MHz, the model attained a minimum EER of 0.35%, while in the high-frequency 1.25 GHz scenario, it achieved an EER of 5.23%. These results indicate that the architecture effectively preserves recognition performance despite significant differences in sampling rates.
By combining attention-based channel feature selection, multi-scale temporal modeling, and local signal enhancement, the method addresses both cross-sampling-rate adaptability and high-frequency feature extraction challenges. This work demonstrates practical value in enhancing EM security detection systems and offers a scalable approach for future EM analysis in multi-rate environments.
