IEEE Transactions on Plasma Science最新文献

{"title":"A Method Based on STFT and Improved Itoh for the Phase Processing of J-TEXT Polarimeter-Interferometer","authors":"Mengxiang Xie;Weijie Lin;Li Gao;Nengchao Wang;ZeKai Guo;Mingqiao Wen;Jiale Wang;Haolei Wei;Hanyi Wang","doi":"10.1109/TPS.2026.3662484","DOIUrl":"https://doi.org/10.1109/TPS.2026.3662484","url":null,"abstract":"Plasma electron density is a critical parameter in tokamak physics, essential for both discharge control and performance evaluation. With advanced tokamak operations requiring higher accuracy and real-time capability, a high-precision density parameter is significant for the J-TEXT research program. This work presents an optimized signal processing scheme for electron density measurement using the polarimeter-interferometer system on the J-TEXT tokamak. To achieve high-precision processing of electron density signals in noisy environments, the fast Fourier transform (FFT) with inverse FFT (FFT-IFFT) method and the short-time Fourier transform (STFT) are rigorously benchmarked based on their absolute phase error, with the STFT algorithm identified as superior owing to its robust noise immunity, achieving a mean absolute error of approximately 0.02 rad under Gaussian white noise (intensity of 0.1)—an order of magnitude lower than the 0.5 rad error of the FFT-IFFT method. In addition, to address the common issue of phase wrapping in practical measurements, an outlier detection method and an error identification mechanism are introduced to refine the phase unwrapping process, thereby effectively preventing error accumulation. The proposed algorithm has been successfully implemented in J-TEXT experiments, yielding a notable improvement in phase unwrapping accuracy and considerably enhancing the reliability of density measurements.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1270-1274"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Approach to Refractive Index Sensing Using Fano Resonance in Optical Fiber Platforms","authors":"Rajiv Maurya;Ayushi Rawat;Ankit Mishra;Chandan Singh Yadav;Abhishek Upadhyay;Gaurav Sharma;Vivek Singh","doi":"10.1109/TPS.2026.3660719","DOIUrl":"https://doi.org/10.1109/TPS.2026.3660719","url":null,"abstract":"A novel optical fiber sensor, clad with three distinct materials of finite thickness as inspired by planar waveguide-coupled surface plasmon resonance (SPR) configurations, is proposed to excite Fano resonance (FR) for ultrasensitive refractive index detection. The transmission power of the sensor exhibits a pronounced asymmetric line shape, a hallmark of FR. Using the intensity-interrogation method, it achieves a remarkable figure of merit (FOM) of 91 410.90 a.u./RIU, compared to 114.95 a.u./RIU for conventional fiber SPR sensors, representing approximately 795 times enhancement of sensitivity. This remarkable FOM improvement arises from the ultranarrow linewidth and steep spectral slope of the FR mode, enabling superior sensing performance over traditional SPR-based sensors.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1192-1199"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable Control of Optical Wave Characteristics in High-Power Laser Systems via Two-Beam Coupling in Plasma","authors":"Ali Adineh;Mehran Shahmansouri","doi":"10.1109/TPS.2025.3640966","DOIUrl":"https://doi.org/10.1109/TPS.2025.3640966","url":null,"abstract":"In the present study, tunable manipulation of the optical wave properties is investigated via the two-beam coupling phenomenon in both homogeneous and inhomogeneous nonlinear media, considering the parallel-beam configuration. The proposed model comprises two optical waves that enter the medium, and in addition to their interaction with the host material, they mutually exchange energy. This interaction engenders modifications in the amplitude, phase, and polarization state of the waves. Given the inherent flexibility in adjusting plasma parameters, plasma is employed as the nonlinear medium in this investigation. Considering the critical importance of tailoring optical characteristics—particularly the polarization state—for applications such as high-power lasers in electrodynamic systems, high-harmonic generation, laser fusion, and optical switching, the results of this study bear significant practical implications.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1150-1163"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FBG Sensors Assisted Programmable Device for Plantar Pressure Measurement","authors":"Anand Prakash Narayan;Ibrar Jahan Mohammed Aslam;Sunit Goel;Parimal Sah;Yogendra Kumar Awasthi;Gaurav Kumar Bharti","doi":"10.1109/TPS.2026.3653497","DOIUrl":"https://doi.org/10.1109/TPS.2026.3653497","url":null,"abstract":"This article presents a programmable device for plantar pressure measurement using fiber Bragg grating (FBG) sensors, integrated with a Python-based interface for data visualization, foot classification, and report generation. The device measures pressure at five key foot locations, classifying feet into categories such as normal, flat, pronated, supinated, and abnormal. The system demonstrates high sensitivity (355.98 pm/kPa for left foot, 384.60 pm/kPa for right foot) and operates efficiently with a calibration factor of 6.4474. The interface features data storage, email functionality, and pdf report generation, making it suitable for clinical and healthcare applications. The study includes calibration and experimental validation with 70 subjects, and discusses potential future integrations, such as screen mounting for enhanced usability.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1171-1179"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband Cross-Polarization Conversion in a Graphene-Assisted Metasurface for Chemical Detection","authors":"Taha Sheheryar;Bo Lv;Sijie Wang;He Sun;Huibin Tao","doi":"10.1109/TPS.2026.3658827","DOIUrl":"https://doi.org/10.1109/TPS.2026.3658827","url":null,"abstract":"A graphene-integrated reflective design is proposed that breaks the bandwidth, tunability, and single-function limits of typical terahertz polarization converters. The structure achieves linear-to-cross conversion above 90% from 9.823 to 17.844 THz with an 8.021-THz span and a mean polarization conversion of 98.93%. Within 10.08–17.71 THz, polarization conversion ratio (PCR) remains above 95% with a 99.25% average while segmented windows totaling 7.2 THz exceed 98% with 99.40% average and peak values surpass 99.99% at multiple resonances. Performance is stable under oblique incidence retaining band-averaged PCRs of 98.21% and 98.49% at 24°. Real-time reconfiguration is aided through electrical control of the graphene Fermi level requiring no geometric change. As a sensor, the design resolves small refractive-index shifts with a maximum sensitivity of 2.20 THz/RIU and differentiates representative chemical analytes through consistent frequency shifts. The combined attributes of ultraefficient broadband conversion, strong angular tolerance, electrical tunability, and high sensing accuracy establish this design as a compact and fabrication-friendly candidate for integrated terahertz polarization control and chemical sensing.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1236-1249"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blank Page","authors":"","doi":"10.1109/TPS.2026.3669327","DOIUrl":"https://doi.org/10.1109/TPS.2026.3669327","url":null,"abstract":"","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"C4-C4"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11440024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation of Plasma Vertical Growth Rate in Vertical Displacement Events on EAST","authors":"Guojiang Wu;Yong Guo;Chengyue Liu","doi":"10.1109/TPS.2026.3662360","DOIUrl":"https://doi.org/10.1109/TPS.2026.3662360","url":null,"abstract":"Vertical instability in elongated plasmas presents a critical challenge for tokamak operation, as it may initiate vertical displacement events (VDEs) capable of causing severe device damage. The Tokamak Simulation Code (TSC) has been proven to be a valuable tool for simulating and understanding these phenomena on the Experimental Advanced Superconducting Tokamak (EAST). In this study, we employ TSC’s validated free-drift model to simulate the temporal evolution of the plasma vertical position <inline-formula> <tex-math>$boldsymbol {Z}_{boldsymbol {c}}$ </tex-math></inline-formula> across various EAST equilibrium configurations. The plasma vertical growth rate <inline-formula> <tex-math>$boldsymbol {gamma }$ </tex-math></inline-formula>, a fundamental parameter for instability characterization and control, is extracted from <inline-formula> <tex-math>$boldsymbol {Z}_{boldsymbol {c}}$ </tex-math></inline-formula> dynamics. Through comprehensive parameters scans, we investigate the dependence of <inline-formula> <tex-math>$boldsymbol {gamma }$ </tex-math></inline-formula> on key equilibrium parameters, such as major radius <inline-formula> <tex-math>$boldsymbol {R}_{boldsymbol {0}}$ </tex-math></inline-formula>, minor radius <inline-formula> <tex-math>$boldsymbol {a}$ </tex-math></inline-formula>, plasma current <inline-formula> <tex-math>$boldsymbol {I}_{boldsymbol {p}}$ </tex-math></inline-formula>, elongation <inline-formula> <tex-math>$boldsymbol {kappa }$ </tex-math></inline-formula>, poloidal beta <inline-formula> <tex-math>$boldsymbol {beta }_{boldsymbol {P}}$ </tex-math></inline-formula>, and internal inductance <inline-formula> <tex-math>$boldsymbol {l}_{boldsymbol {i}}$ </tex-math></inline-formula>. Furthermore, the artificial neural network (ANN) method is trained on extensive TSC-generated equilibrium datasets. Such a data-driven approach enables the identification of the plasma vertical growth rate through global plasma parameters within a reasonable error range.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1200-1209"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Terahertz Band Backward-Wave Oscillator Based on Folded Waveguide Slow Wave Structure With Multiple Sheet Beams","authors":"Yanan Ma;Rui Zhang;Fengying Lu;Yong Wang","doi":"10.1109/TPS.2026.3661339","DOIUrl":"https://doi.org/10.1109/TPS.2026.3661339","url":null,"abstract":"A terahertz (THz) backward-wave oscillator (BWO) based on a folded waveguide (FW) structure and driven by multiple sheet beams (MSBs) is proposed and investigated. The BWO employs three parallel sheet beams to enhance beam–wave interaction. By conducting particle-in-cell (PIC) simulations, the MSB-FW BWO demonstrates self-oscillation at a beam voltage of 13.5 kV and a beam current of 0.3 A, delivering an output power exceeding 95 W. The BWO supports a voltage-controlled tuning range of 27 GHz, spanning from 228 to 255 GHz. Throughout the entire tuning range, the BWO maintains a high spectral purity, with clear single-frequency output observed. These results confirm that the MSB-FW BWO is a competitive solution for THz radiation sources.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"1229-1235"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-Evolved Constant Voltage Conductivity Measurements of Common Spaceborne Polymeric Materials","authors":"Brian Wood;David King;J. R. Dennison","doi":"10.1109/TPS.2025.3596532","DOIUrl":"https://doi.org/10.1109/TPS.2025.3596532","url":null,"abstract":"Long-duration current measurements were made for low-density polyethylene (LDPE), polyimide (PI), polyether ether ketone (PEEK), and biaxially oriented polypropylene (BOPP) to determine their bulk conductivity near room temperature as a function of time. These common thin-film spacecraft material samples were vacuum baked to remove moisture and volatile contaminants to better simulate space conditions. The constant voltage conductivity (CVC) method used a very stable, low-noise dc voltage source and measured the resulting current in a parallel plate geometry. Due to the extremely low conductivity of these four polymeric materials, extended experiments of up to ten days were necessary to establish equilibrium current flow and determine the saturated conductivity. The lower instrumental limit of conductivity measurements with this setup is <inline-formula> <tex-math>$2cdot {10}^{-21} (Omega cdot mathrm {cm})^{-1}$ </tex-math></inline-formula>. Changes in conductivity due to field-enhanced conductivity and radiation induced conductivity (RIC) as well as varying voltages, temperatures and dose rates are also considered. Current data for each material are fit to a multiterm model to account for the different electric and displacement charge transport contributions within highly disordered insulating materials (HDIMs), including polarization, dispersive transport, and saturated current. The regimes of disorder-induced dispersive transport demarcated by the transit time are observed in all materials, indicative of hopping transport between trap states in HDIM. Information on the energy distribution of localized trap states responsible for electron conduction in HDIM is extracted from the fitting parameters. Magnitudes and time-dependence of conductivity are reported, along with estimated polarization, transit, equilibrium, and decay times; these are compared favorably with previous measurements using constant voltage and charge storage decay conductivity test methods. These fits can be used with model simulations of time-dependent spacecraft charging to determine nonequilibrium transient conductivity for specific applications.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"900-910"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-Dependent Radiation Induced Conductivity of Polyimide: Effects of Dose Rate and Temperature on Dynamic RIC","authors":"Tyler Heggenes;Jenny R. Whiteley;Jodie Corbridge Gillespie;J. R. Dennison","doi":"10.1109/TPS.2025.3615922","DOIUrl":"https://doi.org/10.1109/TPS.2025.3615922","url":null,"abstract":"Radiation induced conductivity (RIC) can impact charge dissipation within highly insulating materials used in spacecraft in harsh space plasma environments. Previous Utah State University (USU) research analyzed only the equilibrium portions of an extensive RIC database for polymeric materials, including Kapton HN (Trademark). This confirmed that equilibrium RIC follows a standard theoretical model that is temperature and dose rate dependent. The current study provides a new analysis of RIC’s time-dependent behavior of the Kapton HN data from this database. With the onset of radiation, the material response is characterized by an exponential increase in conductivity, while a hyperbolic inverse time-dependent decline characterizes the decay of delayed RIC. A model with dual fast and slow time constants, representing the capture and release of charges from shallow and deep traps, respectively, produces the best fits to time-dependent RIC from successive dosing cycles at fixed temperatures. This dual-defect model provides information about the dose rate and temperature dependence of material properties in response to dynamic (time-dependent) RIC and helps infer relative trap state distributions and occupancy of the material.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"54 3","pages":"889-899"},"PeriodicalIF":1.5,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147558017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}