Flexible antennas are widely used in mobile communications, the Internet of Things, personalized medicine, aerospace, and military technologies due to their superior performance in terms of adaptability, impact resistance, high degree of freedom, miniaturization of structures, and cost-effectiveness. With excellent flexibility and portability, these antennas are now being integrated into paper, textiles, and even the human body to withstand the various mechanical stresses of daily life without compromising their performance. The purpose of this paper is to provide a comprehensive overview of the basic principles and current development of flexible antennas, systematically analyze the key performance factors of flexible antennas, such as structure, process, material, and application environment, and then discuss in detail the design structure, material selection, preparation process, and corresponding experimental validation of flexible antennas. Flexible antenna design in mobile communication, wearable devices, biomedical technology, and other fields in recent years has been emphasized. Finally, the development status of flexible antenna technology is summarized, and its future development trend and research direction are proposed.
{"title":"The effect of feed mechanisms on the structural design of flexible antennas, and research on their material processing and applications","authors":"Xueli Nan, Bolin Qin, Zhikuan Xu, Qikun Jia, Jinjin Hao, Xinxin Cao, Shixuan Mei, Xin Wang, Tongtong Kang, Jiale Zhang, Tingting Bai","doi":"10.1063/5.0206788","DOIUrl":"https://doi.org/10.1063/5.0206788","url":null,"abstract":"Flexible antennas are widely used in mobile communications, the Internet of Things, personalized medicine, aerospace, and military technologies due to their superior performance in terms of adaptability, impact resistance, high degree of freedom, miniaturization of structures, and cost-effectiveness. With excellent flexibility and portability, these antennas are now being integrated into paper, textiles, and even the human body to withstand the various mechanical stresses of daily life without compromising their performance. The purpose of this paper is to provide a comprehensive overview of the basic principles and current development of flexible antennas, systematically analyze the key performance factors of flexible antennas, such as structure, process, material, and application environment, and then discuss in detail the design structure, material selection, preparation process, and corresponding experimental validation of flexible antennas. Flexible antenna design in mobile communication, wearable devices, biomedical technology, and other fields in recent years has been emphasized. Finally, the development status of flexible antenna technology is summarized, and its future development trend and research direction are proposed.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xianggang Hu, Jiancang Su, Bing Bai, Zengqiang Yu, Xiaogang Lu, Mei Li, Rui Li, Jie Cheng, Jiande Zhang, Shaotong Wu
Phase shifter (PS) is a key component of a phased array antenna (PAA) system, which controls the microwave phase and realizes the antenna beam forming and scanning. A ferrite PS (FPS) is a current-controlled PS that uses the ferrite’s gyromagnetic properties to realize phase shifting. It has the advantages of short phase switching time, low microwave loss, and high reliability and, therefore, has been widely used in low-power PAA systems. However, the power handling capability of the traditional Ku-band FPS is only a few kW, prohibiting FPS from being used in high-power microwave (HPM) PAA systems. Spurred by this concern, this paper proposes a new dual-toroid FPS structure with an external magnetic excitation. By optimizing the PS configuration, improving the integration process, and enhancing the performance of ferrite materials, a single FPS in the Ku band has reached the power handling capability of more than 300 kW with an insertion loss of less than −1.2 dB, the phase shift range of 0°–360°, the width less than 11.5 mm, and the ability of a one-dimensional array. The FPS has the potential to be used in the PAA of an HPM system, laying a foundation for the research of the HPM PAA system.
{"title":"Ku-band 300 kW high power ferrite phase shifter","authors":"Xianggang Hu, Jiancang Su, Bing Bai, Zengqiang Yu, Xiaogang Lu, Mei Li, Rui Li, Jie Cheng, Jiande Zhang, Shaotong Wu","doi":"10.1063/5.0211304","DOIUrl":"https://doi.org/10.1063/5.0211304","url":null,"abstract":"Phase shifter (PS) is a key component of a phased array antenna (PAA) system, which controls the microwave phase and realizes the antenna beam forming and scanning. A ferrite PS (FPS) is a current-controlled PS that uses the ferrite’s gyromagnetic properties to realize phase shifting. It has the advantages of short phase switching time, low microwave loss, and high reliability and, therefore, has been widely used in low-power PAA systems. However, the power handling capability of the traditional Ku-band FPS is only a few kW, prohibiting FPS from being used in high-power microwave (HPM) PAA systems. Spurred by this concern, this paper proposes a new dual-toroid FPS structure with an external magnetic excitation. By optimizing the PS configuration, improving the integration process, and enhancing the performance of ferrite materials, a single FPS in the Ku band has reached the power handling capability of more than 300 kW with an insertion loss of less than −1.2 dB, the phase shift range of 0°–360°, the width less than 11.5 mm, and the ability of a one-dimensional array. The FPS has the potential to be used in the PAA of an HPM system, laying a foundation for the research of the HPM PAA system.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. E. Palmer, L. R. Benedetti, C. E. Vennari, P. R. Nyholm, R. B. Petre, N. Bhandarkar, A. C. Carpenter, S. R. Nagel, J. H. Eggert, D. K. Bradley, A. J. Mackinnon, Y. Ping
As part of a program to measure phase transition timescales in materials under dynamic compression, we have designed new x-ray imaging diagnostics to record multiple x-ray diffraction measurements during a single laser-driven experiment. Our design places several ns-gated hybrid CMOS (hCMOS) sensors within a few cm of a laser-driven target. The sensors must be protected from an extremely harsh environment, including debris, electromagnetic pulses, and unconverted laser light. Another key challenge is reducing the x-ray background relative to the faint diffraction signal. Building on the success of our predecessor (Target Diffraction In Situ), we implemented a staged approach to platform development. First, we built a demonstration diagnostic (Gated Diffraction Development Diagnostic) with two hCMOS sensors to confirm we could adequately protect them from the harsh environment and also acquire acceptable diffraction data. This allowed the team to quickly assess the risks and address the most significant challenges. We also collected scientifically useful data during development. Leveraging what we learned, we recently developed a much more ambitious instrument (Flexible Imaging Diffraction Diagnostic for Laser Experiments) that can field up to eight hCMOS sensors in a flexible geometry and participate in back-to-back shots at the National Ignition Facility (NIF). The design also allows for future iterations, such as faster hCMOS sensors and an embedded x-ray streak camera. The enhanced capabilities of the new instrument required a much more complex design, and the unexpected issues encountered on the first few shots at NIF remind us that complexity has consequences. Our progress in addressing these challenges is described herein, as is our current focus on improving data quality by reducing x-ray background and quantifying the uncertainties of our diffraction measurements.
作为测量动态压缩条件下材料相变时间尺度计划的一部分，我们设计了新型 X 射线成像诊断装置，用于在单次激光驱动实验中记录多次 X 射线衍射测量结果。我们的设计将几个 ns 门控混合 CMOS（hCMOS）传感器置于激光驱动目标的几厘米范围内。这些传感器必须受到保护，以免受到极端恶劣环境的影响，包括碎片、电磁脉冲和未转换的激光。另一个关键挑战是减少相对于微弱衍射信号的 X 射线背景。在我们的前身（原位目标衍射）取得成功的基础上，我们采用了一种分阶段的平台开发方法。首先，我们用两个 hCMOS 传感器制作了一个演示诊断仪（门控衍射开发诊断仪），以确认我们能够充分保护它们免受恶劣环境的影响，同时还能获取可接受的衍射数据。这使团队能够快速评估风险，解决最重大的挑战。我们还在开发过程中收集了有用的科学数据。利用我们所学到的知识，我们最近开发出了一种更加雄心勃勃的仪器（用于激光实验的柔性成像衍射诊断仪），它可以在灵活的几何形状中安装多达八个 hCMOS 传感器，并参与国家点火装置（NIF）的背靠背发射。该设计还允许未来的迭代，如更快的 hCMOS 传感器和嵌入式 X 射线条纹照相机。新仪器功能的增强需要更复杂的设计，而在 NIF 的前几次拍摄中遇到的意想不到的问题提醒我们，复杂性也会带来后果。本文介绍了我们在应对这些挑战方面取得的进展，以及我们目前通过减少 X 射线背景和量化衍射测量的不确定性来提高数据质量的工作重点。
{"title":"Developing time-resolved x-ray diffraction diagnostics at the National Ignition Facility (invited)","authors":"N. E. Palmer, L. R. Benedetti, C. E. Vennari, P. R. Nyholm, R. B. Petre, N. Bhandarkar, A. C. Carpenter, S. R. Nagel, J. H. Eggert, D. K. Bradley, A. J. Mackinnon, Y. Ping","doi":"10.1063/5.0219574","DOIUrl":"https://doi.org/10.1063/5.0219574","url":null,"abstract":"As part of a program to measure phase transition timescales in materials under dynamic compression, we have designed new x-ray imaging diagnostics to record multiple x-ray diffraction measurements during a single laser-driven experiment. Our design places several ns-gated hybrid CMOS (hCMOS) sensors within a few cm of a laser-driven target. The sensors must be protected from an extremely harsh environment, including debris, electromagnetic pulses, and unconverted laser light. Another key challenge is reducing the x-ray background relative to the faint diffraction signal. Building on the success of our predecessor (Target Diffraction In Situ), we implemented a staged approach to platform development. First, we built a demonstration diagnostic (Gated Diffraction Development Diagnostic) with two hCMOS sensors to confirm we could adequately protect them from the harsh environment and also acquire acceptable diffraction data. This allowed the team to quickly assess the risks and address the most significant challenges. We also collected scientifically useful data during development. Leveraging what we learned, we recently developed a much more ambitious instrument (Flexible Imaging Diffraction Diagnostic for Laser Experiments) that can field up to eight hCMOS sensors in a flexible geometry and participate in back-to-back shots at the National Ignition Facility (NIF). The design also allows for future iterations, such as faster hCMOS sensors and an embedded x-ray streak camera. The enhanced capabilities of the new instrument required a much more complex design, and the unexpected issues encountered on the first few shots at NIF remind us that complexity has consequences. Our progress in addressing these challenges is described herein, as is our current focus on improving data quality by reducing x-ray background and quantifying the uncertainties of our diffraction measurements.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We introduce an extreme ultraviolet (XUV)-beamline designed for the time-resolved investigation and coherent control of attosecond (as) electron dynamics in atoms and molecules by polarization-shaped as-laser pulses. Shaped as-pulses are generated through high-harmonic generation (HHG) of tailored white-light supercontinua (WLS) in noble gases. The interaction of shaped as-pulses with the sample is studied using velocity map imaging (VMI) techniques to achieve the differential detection of photoelectron wave packets. The instrument consists of the WLS-beamline, which includes a hollow-core fiber compressor and a home-built 4f polarization pulse shaper, and the high-vacuum XUV-beamline, which combines an HHG-stage and a versatile multi-experiment vacuum chamber equipped with a home-built VMI spectrometer. The VMI spectrometer allows the detection of photoelectron wave packets from both the multiphoton ionization (MPI) of atomic or molecular samples by the tailored WLS-pulses and the single-photon ionization (SPI) by the shaped XUV-pulses. To characterize the VMI spectrometer, we studied the MPI of xenon atoms by linearly polarized WLS pulses. To validate the interplay of these components, we conducted experiments on the SPI of xenon atoms with linearly polarized XUV-pulses. Our results include the reconstruction of the 3D photoelectron momentum distribution (PMD) and initial findings on the coherent control of the PMD by tuning the spectrum of the XUV-pulses with the spectral phase of the WLS. Our results demonstrate the performance of the entire instrument for HHG-based photoelectron imaging spectroscopy with prototypical shaped pulses. Perspectively, we will employ polarization-tailored WLS-pulses to generate polarization-shaped as-pulses.
{"title":"XUV-beamline for photoelectron imaging spectroscopy with shaped pulses","authors":"M. Behrens, L. Englert, T. Bayer, M. Wollenhaupt","doi":"10.1063/5.0223450","DOIUrl":"https://doi.org/10.1063/5.0223450","url":null,"abstract":"We introduce an extreme ultraviolet (XUV)-beamline designed for the time-resolved investigation and coherent control of attosecond (as) electron dynamics in atoms and molecules by polarization-shaped as-laser pulses. Shaped as-pulses are generated through high-harmonic generation (HHG) of tailored white-light supercontinua (WLS) in noble gases. The interaction of shaped as-pulses with the sample is studied using velocity map imaging (VMI) techniques to achieve the differential detection of photoelectron wave packets. The instrument consists of the WLS-beamline, which includes a hollow-core fiber compressor and a home-built 4f polarization pulse shaper, and the high-vacuum XUV-beamline, which combines an HHG-stage and a versatile multi-experiment vacuum chamber equipped with a home-built VMI spectrometer. The VMI spectrometer allows the detection of photoelectron wave packets from both the multiphoton ionization (MPI) of atomic or molecular samples by the tailored WLS-pulses and the single-photon ionization (SPI) by the shaped XUV-pulses. To characterize the VMI spectrometer, we studied the MPI of xenon atoms by linearly polarized WLS pulses. To validate the interplay of these components, we conducted experiments on the SPI of xenon atoms with linearly polarized XUV-pulses. Our results include the reconstruction of the 3D photoelectron momentum distribution (PMD) and initial findings on the coherent control of the PMD by tuning the spectrum of the XUV-pulses with the spectral phase of the WLS. Our results demonstrate the performance of the entire instrument for HHG-based photoelectron imaging spectroscopy with prototypical shaped pulses. Perspectively, we will employ polarization-tailored WLS-pulses to generate polarization-shaped as-pulses.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thomas Rood, Sonu Yadav, Gustavo Bartolo, Earl Scime
An array of compact, high-bandwidth (>200 MHz) and low-cost optical photodiodes has been developed and implemented on the PHASe MApping (PHASMA) experiment. Using purpose-built electronics, an array of 16 photodetectors was constructed and used to monitor broadband (1–5 MHz) fluctuations in light intensity emitted by flux ropes undergoing electron-only magnetic reconnection. These measurements reveal a swath of oscillatory behavior, including wave propagation inward toward the diffusion region at approximately the local electron Alfvén speed. Custom 3D-printed collection optics and mounting hardware allow quick reconfiguration of the array for radial or axial measurements. The electronics design is flexible enough to be used with other current-sourcing transducers, such as avalanche photodiodes; silicon photomultipliers; and infrared, x-ray, and UV photodiodes. A noise-rejecting electrical layout allows for low-noise operation close to pulsed plasma discharges. A 16-channel, 64-pixel tomographic array was constructed and initial reconstructions are presented.
{"title":"Fast photodiode arrays for high frequency fluctuation measurements of reconnecting flux ropes","authors":"Thomas Rood, Sonu Yadav, Gustavo Bartolo, Earl Scime","doi":"10.1063/5.0219515","DOIUrl":"https://doi.org/10.1063/5.0219515","url":null,"abstract":"An array of compact, high-bandwidth (>200 MHz) and low-cost optical photodiodes has been developed and implemented on the PHASe MApping (PHASMA) experiment. Using purpose-built electronics, an array of 16 photodetectors was constructed and used to monitor broadband (1–5 MHz) fluctuations in light intensity emitted by flux ropes undergoing electron-only magnetic reconnection. These measurements reveal a swath of oscillatory behavior, including wave propagation inward toward the diffusion region at approximately the local electron Alfvén speed. Custom 3D-printed collection optics and mounting hardware allow quick reconfiguration of the array for radial or axial measurements. The electronics design is flexible enough to be used with other current-sourcing transducers, such as avalanche photodiodes; silicon photomultipliers; and infrared, x-ray, and UV photodiodes. A noise-rejecting electrical layout allows for low-noise operation close to pulsed plasma discharges. A 16-channel, 64-pixel tomographic array was constructed and initial reconstructions are presented.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu Liu, Utkarsh Pratiush, Jason Bemis, Roger Proksch, Reece Emery, Philip D. Rack, Yu-Chen Liu, Jan-Chi Yang, Stanislav Udovenko, Susan Trolier-McKinstry, Sergei V. Kalinin
The rapid development of computation power and machine learning algorithms has paved the way for automating scientific discovery with a scanning probe microscope (SPM). The key elements toward operationalization of the automated SPM are the interface to enable SPM control from Python codes, availability of high computing power, and development of workflows for scientific discovery. Here, we build a Python interface library that enables controlling an SPM from either a local computer or a remote high-performance computer, which satisfies the high computation power need of machine learning algorithms in autonomous workflows. We further introduce a general platform to abstract the operations of SPM in scientific discovery into fixed-policy or reward-driven workflows. Our work provides a full infrastructure to build automated SPM workflows for both routine operations and autonomous scientific discovery with machine learning.
{"title":"Integration of scanning probe microscope with high-performance computing: Fixed-policy and reward-driven workflows implementation","authors":"Yu Liu, Utkarsh Pratiush, Jason Bemis, Roger Proksch, Reece Emery, Philip D. Rack, Yu-Chen Liu, Jan-Chi Yang, Stanislav Udovenko, Susan Trolier-McKinstry, Sergei V. Kalinin","doi":"10.1063/5.0219990","DOIUrl":"https://doi.org/10.1063/5.0219990","url":null,"abstract":"The rapid development of computation power and machine learning algorithms has paved the way for automating scientific discovery with a scanning probe microscope (SPM). The key elements toward operationalization of the automated SPM are the interface to enable SPM control from Python codes, availability of high computing power, and development of workflows for scientific discovery. Here, we build a Python interface library that enables controlling an SPM from either a local computer or a remote high-performance computer, which satisfies the high computation power need of machine learning algorithms in autonomous workflows. We further introduce a general platform to abstract the operations of SPM in scientific discovery into fixed-policy or reward-driven workflows. Our work provides a full infrastructure to build automated SPM workflows for both routine operations and autonomous scientific discovery with machine learning.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Jeet, B. D. Appelbe, A. J. Crilly, L. Divol, M. Eckart, K. D. Hahn, E. P. Hartouni, A. Hayes, S. Kerr, Y. Kim, E. Mariscal, A. S. Moore, A. Ramirez, G. Rusev, D. J. Schlossberg
In the push to higher performance fusion plasmas, two critical quantities to diagnose are α-heat deposition that can improve and impurities mixed into the plasma that can limit performance. In high-density, highly collisional inertial confinement fusion burning plasmas, there is a significant probability that deuterium–tritium (DT) fusion products, 14.1 MeV neutrons and 3.5 MeV α-particles, will collide with and deposit energy onto (“up-scatter”) surrounding deuterium and tritium fuel ions. These up-scattered D and T ions can then undergo fusion while in-flight and produce an up-scattered neutron (15–30 MeV). These reaction-in-flight (RIF) neutrons can then be uniquely identified in the measured neutron energy spectrum. The magnitude, shape, and relative size of this spectral feature can inform models of stopping-power in the DT plasma and hence is directly proportional to α-heat deposition. In addition, the RIF spectrum can be related to mix into the burning fuel, particularly relevant for high-Z shell and other emerging National Ignition Facility platforms. The neutron time-of-flight diagnostic upgrades needed to obtain this small signal, ∼10−5 times the primary DT neutron peak, will be discussed. Results from several gain > 1 implosions will be shown and compared to previous RIF spectra. Finally, comparisons of experimental data to a simplified computational model will be made.
{"title":"Diagnosing up-scattered deuterium–tritium fusion neutrons produced in burning plasmas at the National Ignition Facility (invited)","authors":"J. Jeet, B. D. Appelbe, A. J. Crilly, L. Divol, M. Eckart, K. D. Hahn, E. P. Hartouni, A. Hayes, S. Kerr, Y. Kim, E. Mariscal, A. S. Moore, A. Ramirez, G. Rusev, D. J. Schlossberg","doi":"10.1063/5.0219671","DOIUrl":"https://doi.org/10.1063/5.0219671","url":null,"abstract":"In the push to higher performance fusion plasmas, two critical quantities to diagnose are α-heat deposition that can improve and impurities mixed into the plasma that can limit performance. In high-density, highly collisional inertial confinement fusion burning plasmas, there is a significant probability that deuterium–tritium (DT) fusion products, 14.1 MeV neutrons and 3.5 MeV α-particles, will collide with and deposit energy onto (“up-scatter”) surrounding deuterium and tritium fuel ions. These up-scattered D and T ions can then undergo fusion while in-flight and produce an up-scattered neutron (15–30 MeV). These reaction-in-flight (RIF) neutrons can then be uniquely identified in the measured neutron energy spectrum. The magnitude, shape, and relative size of this spectral feature can inform models of stopping-power in the DT plasma and hence is directly proportional to α-heat deposition. In addition, the RIF spectrum can be related to mix into the burning fuel, particularly relevant for high-Z shell and other emerging National Ignition Facility platforms. The neutron time-of-flight diagnostic upgrades needed to obtain this small signal, ∼10−5 times the primary DT neutron peak, will be discussed. Results from several gain > 1 implosions will be shown and compared to previous RIF spectra. Finally, comparisons of experimental data to a simplified computational model will be made.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Salas-Suárez-Bárcena, L. F. Delgado-Aparicio, J. Segado-Fernández, A. Rodríguez-González, K. A. McKay, D. J. Cruz-Zabala, J. Hidalgo-Salaverri, J. García-Domínguez, M. García-Muñoz, E. Viezzer, J. Galdón-Quiroga
A multi-energy soft x-ray diagnostic is planned to operate in the small aspect ratio tokamak (SMART), consisting of five cameras: one for core measurements, two for edge, and two for divertors. Each camera is equipped with four absolute extreme ultra-violet diodes, with three of them filtered by Ti and Al foils for C and O line emissions, respectively, and Be foils for temperature measurements. In addition, two spectrometers will be installed with a vertical line of sight for impurity control. This study introduces a synthetic model designed to characterize radiated power and soft x-ray emissions. The developed code extracts the radiated power and Zeff values by leveraging distributions of electron density, temperatures, and impurity concentrations. The investigation is centered on the predicted scenarios of SMART’s first phase of operation (Ip = 100 kA; Bt = 0.1 T), employing a double-null configuration with positive and negative triangularity. The anticipated impurities encompass C (1%) and Fe (0.01%) from the vessel, as well as O and N (0.1%) from air and water. For simplicity, the distribution is assumed to be homogeneous within the plasma, considering different mixtures with Zeff values ranging between 1 and 2. Finally, the model estimates signal strength for the diagnostic design, proving its feasibility.
计划在小长径比托卡马克（SMART）中运行多能量软 X 射线诊断仪，该诊断仪由五台照相机组成：一台用于核心测量，两台用于边缘测量，两台用于分流器测量。每台照相机都配备了四个绝对极紫外二极管，其中三个分别由用于 C 和 O 线发射的钛箔和铝箔以及用于温度测量的铍箔过滤。此外，还将安装两台垂直视线的光谱仪，用于杂质控制。本研究介绍了一个合成模型，旨在描述辐射功率和软 X 射线发射的特征。开发的代码利用电子密度、温度和杂质浓度的分布提取辐射功率和 Zeff 值。研究以 SMART 第一阶段运行（Ip = 100 kA；Bt = 0.1 T）的预测情景为中心，采用了具有正负三角形的双空配置。预期杂质包括来自容器的 C（1%）和 Fe（0.01%），以及来自空气和水的 O 和 N（0.1%）。为简单起见，假设等离子体内的分布是均匀的，同时考虑到 Zeff 值在 1 到 2 之间的不同混合物。最后，该模型估算了诊断设计的信号强度，证明了其可行性。
{"title":"Radiated power and soft x-ray diagnostics in the SMART tokamak","authors":"J. Salas-Suárez-Bárcena, L. F. Delgado-Aparicio, J. Segado-Fernández, A. Rodríguez-González, K. A. McKay, D. J. Cruz-Zabala, J. Hidalgo-Salaverri, J. García-Domínguez, M. García-Muñoz, E. Viezzer, J. Galdón-Quiroga","doi":"10.1063/5.0219506","DOIUrl":"https://doi.org/10.1063/5.0219506","url":null,"abstract":"A multi-energy soft x-ray diagnostic is planned to operate in the small aspect ratio tokamak (SMART), consisting of five cameras: one for core measurements, two for edge, and two for divertors. Each camera is equipped with four absolute extreme ultra-violet diodes, with three of them filtered by Ti and Al foils for C and O line emissions, respectively, and Be foils for temperature measurements. In addition, two spectrometers will be installed with a vertical line of sight for impurity control. This study introduces a synthetic model designed to characterize radiated power and soft x-ray emissions. The developed code extracts the radiated power and Zeff values by leveraging distributions of electron density, temperatures, and impurity concentrations. The investigation is centered on the predicted scenarios of SMART’s first phase of operation (Ip = 100 kA; Bt = 0.1 T), employing a double-null configuration with positive and negative triangularity. The anticipated impurities encompass C (1%) and Fe (0.01%) from the vessel, as well as O and N (0.1%) from air and water. For simplicity, the distribution is assumed to be homogeneous within the plasma, considering different mixtures with Zeff values ranging between 1 and 2. Finally, the model estimates signal strength for the diagnostic design, proving its feasibility.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Prabhudesai, J. Chen, D. L. Brower, D. Finkenthal
Near ion-cyclotron frequency (fci) fluctuations, such as those originating from Global and Compressional Alfvén Eigenmodes (GAEs/CAEs), are expected to be present in future fusion reactors but are not well understood due to the limited availability of core measurements in present-day tokamaks. The measurement bandwidth of the Radial Interferometer–Polarimeter (RIP) diagnostic has been upgraded from 1 to 5 MHz to detect these fluctuations in DIII-D. RIP adopts the three-wave technique for simultaneous polarimetric and interferometric measurements. Solid-state microwave sources operating at 650 GHz are used as probe beams and provide 5 MHz bandwidth for both polarimetric and interferometric measurements. Bandwidths of related hardware, including mixer amplifier, signal cable, and digital phase demodulator, are increased correspondingly. Measurement noise is minimized by reducing the time delay between reference and probe signals to nanosecond level and employing correlation-based techniques. Using the upgraded diagnostic, CAE/GAE-like bursting fluctuations are observed in neutral-beam heated plasmas with toroidal magnetic field Bφ ≈ 1 T. Current upgrades being undertaken would enable the evaluation of toroidal mode number for these modes. This work opens the possibility of better understanding near ion-cyclotron frequency fluctuations in fusion relevant plasmas.
{"title":"Upgrade of DIII-D radial interferometer–polarimeter for large bandwidth, low noise, and toroidal mode number measurements","authors":"G. Prabhudesai, J. Chen, D. L. Brower, D. Finkenthal","doi":"10.1063/5.0217020","DOIUrl":"https://doi.org/10.1063/5.0217020","url":null,"abstract":"Near ion-cyclotron frequency (fci) fluctuations, such as those originating from Global and Compressional Alfvén Eigenmodes (GAEs/CAEs), are expected to be present in future fusion reactors but are not well understood due to the limited availability of core measurements in present-day tokamaks. The measurement bandwidth of the Radial Interferometer–Polarimeter (RIP) diagnostic has been upgraded from 1 to 5 MHz to detect these fluctuations in DIII-D. RIP adopts the three-wave technique for simultaneous polarimetric and interferometric measurements. Solid-state microwave sources operating at 650 GHz are used as probe beams and provide 5 MHz bandwidth for both polarimetric and interferometric measurements. Bandwidths of related hardware, including mixer amplifier, signal cable, and digital phase demodulator, are increased correspondingly. Measurement noise is minimized by reducing the time delay between reference and probe signals to nanosecond level and employing correlation-based techniques. Using the upgraded diagnostic, CAE/GAE-like bursting fluctuations are observed in neutral-beam heated plasmas with toroidal magnetic field Bφ ≈ 1 T. Current upgrades being undertaken would enable the evaluation of toroidal mode number for these modes. This work opens the possibility of better understanding near ion-cyclotron frequency fluctuations in fusion relevant plasmas.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. N. Lobanov, K. A. Sharypov, V. G. Shpak, S. A. Shunailov, M. I. Yalandin, N. M. Zubarev
This paper presents the results of research, development, and testing of magnetically insulated air diodes with replaceable graphite and stainless-steel tubular and coaxial cathodes of various configurations capable of generating directed bunches of runaway electrons. At the anode, the bunches have cross sections shaped as circles or rings with an outer diameter of 1–2 cm. The durations of the bunches, which carry currents of a few to tens of amperes, range from tens of picoseconds to 100 ps, and their charges range from tenths of a nanocoulomb to a few nanocoulombs. The kinetic energy of the bunch electrons at the peak of the current pulse is typically of the order of 150 keV. The bunch parameters are set (and varied) by varying the amplitude and duration of the subnanosecond high-voltage pulse driving the diode; they depend on the cathode material and on the strength and profile of the applied external magnetic field. The bunches, retaining their cross-sectional structure, are brought out from the diode, along the field lines, through a thin foil or mesh anode into the open space with a quasi-uniform magnetic field between two Helmholtz coils. In this space, the samples to be irradiated with electrons, similarly to objects exposed to radiation in various experiments and technological applications, can be placed.
{"title":"Formation of directed wide-aperture flows of runaway electrons in air-filled magnetized diodes","authors":"L. N. Lobanov, K. A. Sharypov, V. G. Shpak, S. A. Shunailov, M. I. Yalandin, N. M. Zubarev","doi":"10.1063/5.0218882","DOIUrl":"https://doi.org/10.1063/5.0218882","url":null,"abstract":"This paper presents the results of research, development, and testing of magnetically insulated air diodes with replaceable graphite and stainless-steel tubular and coaxial cathodes of various configurations capable of generating directed bunches of runaway electrons. At the anode, the bunches have cross sections shaped as circles or rings with an outer diameter of 1–2 cm. The durations of the bunches, which carry currents of a few to tens of amperes, range from tens of picoseconds to 100 ps, and their charges range from tenths of a nanocoulomb to a few nanocoulombs. The kinetic energy of the bunch electrons at the peak of the current pulse is typically of the order of 150 keV. The bunch parameters are set (and varied) by varying the amplitude and duration of the subnanosecond high-voltage pulse driving the diode; they depend on the cathode material and on the strength and profile of the applied external magnetic field. The bunches, retaining their cross-sectional structure, are brought out from the diode, along the field lines, through a thin foil or mesh anode into the open space with a quasi-uniform magnetic field between two Helmholtz coils. In this space, the samples to be irradiated with electrons, similarly to objects exposed to radiation in various experiments and technological applications, can be placed.","PeriodicalId":21111,"journal":{"name":"Review of Scientific Instruments","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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