Nongchao Tan, Ping Wu, Ye Hua, Jun Sun, Yibing Cao, Guangshuai Zhang, Wenhui Huang, Wen-hua Huang
Radio frequency (RF) breakdown can result in pulse shortening and seriously degrade the stability and reliability of relativistic backward wave oscillators (RBWOs). This paper discusses the energy range of electrons causing breakdown traces in slow-wave structures (SWSs) through particle-in-cell (PIC) simulation, numerical calculation, and experimental verification. The PIC simulation and numerical calculation results reveal that the energy of the majority of the field-induced electrons bombarding the SWS surfaces after being accelerated is less than 120 keV. Furthermore, the micro appearances of the breakdown traces in SWSs and the witness targets bombarded directly by electrons of various energy levels have been analyzed. Scanning electron microscope (SEM) shows that the breakdown traces are featured with corrugated morphologies with a wide range and a shallow depth. A mass of craters emerge in the vicinity of the corrugated morphologies. These appearances are quite similar to destructive traces impacted directly by low-energy electrons (around 160 keV). Thus, it is confirmed that the breakdown traces result from the bombardment of low-energy electrons. Therefore, the breakdown mechanism of field-emitted electrons impacting on the structure surfaces in RBWOs has been further improved.
{"title":"Analysis of Destructive Effects with Electron Bombardment in Slow-Wave Structures","authors":"Nongchao Tan, Ping Wu, Ye Hua, Jun Sun, Yibing Cao, Guangshuai Zhang, Wenhui Huang, Wen-hua Huang","doi":"10.1155/2022/8327755","DOIUrl":"https://doi.org/10.1155/2022/8327755","url":null,"abstract":"Radio frequency (RF) breakdown can result in pulse shortening and seriously degrade the stability and reliability of relativistic backward wave oscillators (RBWOs). This paper discusses the energy range of electrons causing breakdown traces in slow-wave structures (SWSs) through particle-in-cell (PIC) simulation, numerical calculation, and experimental verification. The PIC simulation and numerical calculation results reveal that the energy of the majority of the field-induced electrons bombarding the SWS surfaces after being accelerated is less than 120 keV. Furthermore, the micro appearances of the breakdown traces in SWSs and the witness targets bombarded directly by electrons of various energy levels have been analyzed. Scanning electron microscope (SEM) shows that the breakdown traces are featured with corrugated morphologies with a wide range and a shallow depth. A mass of craters emerge in the vicinity of the corrugated morphologies. These appearances are quite similar to destructive traces impacted directly by low-energy electrons (around 160 keV). Thus, it is confirmed that the breakdown traces result from the bombardment of low-energy electrons. Therefore, the breakdown mechanism of field-emitted electrons impacting on the structure surfaces in RBWOs has been further improved.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"42 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88477566","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}
Chuliang Zhou, Ye Tian, Yushan Zeng, Z. Zeng, Ruxin Li
Relativistic surface high harmonics, combined with the use of polarization gating, present a promising route towards intense single attosecond pulses. However, they impose stringent requirements on ultra-high laser contrast and are restricted by large intensity losses in real experiments. Here, we numerically demonstrate that by setting an optimal time delay in the polarization gating scheme, the intensity of the generated single attosecond pulses can become approximately 100 times stronger than that with nonoptimal time delay in the coherent synchrotron emission process. When a petawatt-class driving laser irradiates a solid target, an ultra-dense electron nanobunch and a strong space-charge sheath develop, and the accumulated electrostatic energy is only released in half of the laser cycle when this electron nanobunch moves backward. This process results in the emission of intense high harmonics. Our study provides a reliable method for developing bright attosecond extreme ultraviolet pulses.
{"title":"Bright High-Harmonic Generation through Coherent Synchrotron Emission Based on the Polarization Gating Scheme","authors":"Chuliang Zhou, Ye Tian, Yushan Zeng, Z. Zeng, Ruxin Li","doi":"10.1155/2022/6948110","DOIUrl":"https://doi.org/10.1155/2022/6948110","url":null,"abstract":"Relativistic surface high harmonics, combined with the use of polarization gating, present a promising route towards intense single attosecond pulses. However, they impose stringent requirements on ultra-high laser contrast and are restricted by large intensity losses in real experiments. Here, we numerically demonstrate that by setting an optimal time delay in the polarization gating scheme, the intensity of the generated single attosecond pulses can become approximately 100 times stronger than that with nonoptimal time delay in the coherent synchrotron emission process. When a petawatt-class driving laser irradiates a solid target, an ultra-dense electron nanobunch and a strong space-charge sheath develop, and the accumulated electrostatic energy is only released in half of the laser cycle when this electron nanobunch moves backward. This process results in the emission of intense high harmonics. Our study provides a reliable method for developing bright attosecond extreme ultraviolet pulses.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"226 9","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72447618","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}
M. Rafiei, M. Sahrai, M. Hosseinpour, A. Esfandyari-Kalejahi
Two-dimensional electromagnetic particle-in-cell simulations are carried out to investigate the effect of ion-to-electron mass ratio on the evolution of warm electron beam-plasma instability. Four cases are considered: A: mi/me = 0 (two-electron stream instability); B: mi/me = 1 (pair plasma); C: mi/me = 100; and D: mi/me = 1000. It is shown that the generation of Langmuir waves in the fundamental mode of electron plasma frequency and the subsequent dynamics of large-amplitude solitons are not affected by the ion species. However, it determines the decay process of solitons and the excitation of electromagnetic waves in the second harmonic. In the first two cases, mi/me = 0 and 1, there is no sign of emission in the second harmonic, while the strongest emission in the second harmonic is found for the case of largest mass ratio, mi/me = 1000. This confirms the two-step wave-wave coupling mechanism for the generation of second harmonic electromagnetic waves, which requires the excitation of ion-acoustic waves in the first step. Moreover, the dispersion diagrams of all excited waves are presented.
{"title":"The Effect of Ion-to-Electron Mass Ratio on the Electron Beam-Plasma Interaction","authors":"M. Rafiei, M. Sahrai, M. Hosseinpour, A. Esfandyari-Kalejahi","doi":"10.1155/2021/9216171","DOIUrl":"https://doi.org/10.1155/2021/9216171","url":null,"abstract":"Two-dimensional electromagnetic particle-in-cell simulations are carried out to investigate the effect of ion-to-electron mass ratio on the evolution of warm electron beam-plasma instability. Four cases are considered: A: mi/me = 0 (two-electron stream instability); B: mi/me = 1 (pair plasma); C: mi/me = 100; and D: mi/me = 1000. It is shown that the generation of Langmuir waves in the fundamental mode of electron plasma frequency and the subsequent dynamics of large-amplitude solitons are not affected by the ion species. However, it determines the decay process of solitons and the excitation of electromagnetic waves in the second harmonic. In the first two cases, mi/me = 0 and 1, there is no sign of emission in the second harmonic, while the strongest emission in the second harmonic is found for the case of largest mass ratio, mi/me = 1000. This confirms the two-step wave-wave coupling mechanism for the generation of second harmonic electromagnetic waves, which requires the excitation of ion-acoustic waves in the first step. Moreover, the dispersion diagrams of all excited waves are presented.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"41 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78077988","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}
D. Mancelli, I. Errea, A. Tentori, O. Turianska, H. Larreur, K. Katagiri, N. Ozaki, N. Kamimura, D. Kamibayashi, K. Ishida, H. Ogura, K. Kawasaki, Y. Maeda, Y. Hironaka, K. Shigemori, K. Batani, G. Schaumann, O. Rosmej, P. Neumayer, B. Zielbauer, A. Martynenko, E. Filippov, S. Pikuz, D. Batani
In this work, we present experimental results on the behavior of liquid water at megabar pressure. The experiment was performed using the HIPER (High-Intensity Plasma Experimental Research) laser facility, a uniaxial irradiation chamber of GEKKO XII (GXII) at the Institute of Laser Engineering (ILE), and the PHELIX at GSI (GSI Helmholtz Centre for Heavy Ion Research), a single-beam high-power laser facility, to launch a planar shock into solid multilayered water samples. Equation-of-state data of water H 2 O are obtained in the pressure range 0.50–4.6 Mbar by tuning the laser-drive parameters. The Hugoniot parameters (pressure, density, etc.) and the shock temperature were simultaneously determined by using VISAR and SOP as diagnostic tools and quartz as the standard material for impedance mismatch experiments. Finally, our experimental results are compared with hydrodynamic simulations tested with different equations of state, showing good compatibility with tabulated SESAME tables for water.
在这项工作中，我们给出了在兆巴压力下液态水行为的实验结果。实验使用激光工程研究所(ILE)的高强度等离子体实验研究(HIPER)激光设备，GEKKO XII (GXII)的单轴照射室和GSI (GSI亥姆霍兹重离子研究中心)的PHELIX(单束高功率激光设备)，向固体多层水样中发射平面激波。在0.50 ~ 4.6 Mbar压力范围内，通过调整激光驱动参数，获得了水h2o的状态方程数据。以VISAR和SOP作为诊断工具，石英作为阻抗失配实验的标准材料，同时测定Hugoniot参数(压力、密度等)和冲击温度。最后，将实验结果与不同状态方程下的水动力模拟结果进行了比较，结果表明，我们的实验结果与芝麻水表具有良好的相容性。
{"title":"Shock Hugoniot Data for Water up to 5 Mbar Obtained with Quartz Standard at High-Energy Laser Facilities","authors":"D. Mancelli, I. Errea, A. Tentori, O. Turianska, H. Larreur, K. Katagiri, N. Ozaki, N. Kamimura, D. Kamibayashi, K. Ishida, H. Ogura, K. Kawasaki, Y. Maeda, Y. Hironaka, K. Shigemori, K. Batani, G. Schaumann, O. Rosmej, P. Neumayer, B. Zielbauer, A. Martynenko, E. Filippov, S. Pikuz, D. Batani","doi":"10.1155/2021/4141522","DOIUrl":"https://doi.org/10.1155/2021/4141522","url":null,"abstract":"In this work, we present experimental results on the behavior of liquid water at megabar pressure. The experiment was performed using the HIPER (High-Intensity Plasma Experimental Research) laser facility, a uniaxial irradiation chamber of GEKKO XII (GXII) at the Institute of Laser Engineering (ILE), and the PHELIX at GSI (GSI Helmholtz Centre for Heavy Ion Research), a single-beam high-power laser facility, to launch a planar shock into solid multilayered water samples. Equation-of-state data of water \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 H\u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 O\u0000 \u0000 \u0000 \u0000 are obtained in the pressure range 0.50–4.6 Mbar by tuning the laser-drive parameters. The Hugoniot parameters (pressure, density, etc.) and the shock temperature were simultaneously determined by using VISAR and SOP as diagnostic tools and quartz as the standard material for impedance mismatch experiments. Finally, our experimental results are compared with hydrodynamic simulations tested with different equations of state, showing good compatibility with tabulated SESAME tables for water.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"24 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81689562","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}
M. Rinawa, P. Chauhan, Sintu Kumar, M. K. Singh, H. Singh, Amit Sharma, R. Sharma
In the present paper, filamentous structure formation, associated turbulent spectrum, and density cavity formation phenomena have been investigated for low- β plasma β ≪ m e / m i applicable to the auroral region. A set of dimensionless equations governing the dynamics of three dimensionally propagating inertial Alfvén wave (3D-IAW) and perpendicularly propagating magnetosonic wave (PMSW) has been developed. Ponderomotive force due to 3D-IAW has been included in the dynamics of the PMSW. Numerical simulation has been performed to study the nonlinear coupling of these two waves. From the obtained results, we found that the field intensity localization takes place which may further lead to the additional dissipation/turbulence process for particle heating and acceleration in space plasma. The associated turbulent spectrum is obtained with scaling nearly k − 4.28 at smaller scales (in the dissipation range). Relevance of the obtained results with the observations reported by various spacecrafts such as Hawkeye and Heos 2 has been discussed. Also, density fluctuations (depletion) of ∼ 0.10 n 0 are calculated, which are consistent with the FAST spacecraft observation reported.
在本文中，研究了适用于极光区域的低β等离子体的丝状结构形成、相关的湍流光谱和密度空腔形成现象。建立了三维传播惯性alfvsamn波(3D-IAW)和垂直传播磁声波(PMSW)动力学的一组无量纲方程。由于3D-IAW的有源动力已经包括在PMSW的动力学中。通过数值模拟研究了这两种波的非线性耦合。从得到的结果来看，我们发现场强局域化可能进一步导致空间等离子体中粒子加热和加速的额外耗散/湍流过程。在较小的尺度(在耗散范围内)，相关的湍流谱的标度接近k−4.28。讨论了所获得的结果与鹰眼和Heos 2等各种航天器报告的观测结果的相关性。此外，还计算了密度波动(损耗)为~ 0.10 n / 0，这与FAST航天器观测报告一致。
{"title":"Field Localization and Density Cavitation in Low-Beta Plasmas","authors":"M. Rinawa, P. Chauhan, Sintu Kumar, M. K. Singh, H. Singh, Amit Sharma, R. Sharma","doi":"10.1155/2021/2891080","DOIUrl":"https://doi.org/10.1155/2021/2891080","url":null,"abstract":"In the present paper, filamentous structure formation, associated turbulent spectrum, and density cavity formation phenomena have been investigated for low-\u0000 \u0000 β\u0000 \u0000 plasma \u0000 \u0000 \u0000 \u0000 β\u0000 ≪\u0000 \u0000 \u0000 \u0000 \u0000 m\u0000 \u0000 \u0000 e\u0000 \u0000 \u0000 \u0000 /\u0000 \u0000 \u0000 \u0000 m\u0000 \u0000 \u0000 i\u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 \u0000 applicable to the auroral region. A set of dimensionless equations governing the dynamics of three dimensionally propagating inertial Alfvén wave (3D-IAW) and perpendicularly propagating magnetosonic wave (PMSW) has been developed. Ponderomotive force due to 3D-IAW has been included in the dynamics of the PMSW. Numerical simulation has been performed to study the nonlinear coupling of these two waves. From the obtained results, we found that the field intensity localization takes place which may further lead to the additional dissipation/turbulence process for particle heating and acceleration in space plasma. The associated turbulent spectrum is obtained with scaling nearly \u0000 \u0000 \u0000 \u0000 k\u0000 \u0000 \u0000 −\u0000 4.28\u0000 \u0000 \u0000 \u0000 at smaller scales (in the dissipation range). Relevance of the obtained results with the observations reported by various spacecrafts such as Hawkeye and Heos 2 has been discussed. Also, density fluctuations (depletion) of \u0000 \u0000 ∼\u0000 0.10\u0000 \u0000 \u0000 \u0000 n\u0000 \u0000 \u0000 0\u0000 \u0000 \u0000 \u0000 are calculated, which are consistent with the FAST spacecraft observation reported.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"104 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76075649","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}
D. Yin, J. Liu, G. Shen, H. Du, J. Yang, L. Mao, F. Cai, W. Chai
To accelerate high-intensity heavy-ion beams to high energy in the booster ring (BRing) at the High-Intensity Heavy-Ion Accelerator Facility (HIAF) project, we take the typical reference particle 238U35+, which can be accelerated from an injection energy of 17 MeV/u to the maximal extraction energy of 830 MeV/u, as an example to study the basic processes of longitudinal beam dynamics, including beam capture, acceleration, and bunch merging. The voltage amplitude, the synchronous phase, and the frequency program of the RF system during the operational cycle were given, and the beam properties such as bunch length, momentum spread, longitudinal beam emittance, and beam loss were derived, firstly. Then, the beam properties under different voltage amplitude and synchronous phase errors were also studied, and the results were compared with the cases without any errors. Next, the beam properties with the injection energy fluctuation were also studied. The tolerances of the RF errors and injection energy fluctuation were dictated based on the CISP simulations. Finally, the effect of space charge at the low injection energy with different beam intensities on longitudinal emittance and beam loss was evaluated.
{"title":"Longitudinal Beam Dynamics for the Heavy-Ion Synchrotron Booster Ring at HIAF","authors":"D. Yin, J. Liu, G. Shen, H. Du, J. Yang, L. Mao, F. Cai, W. Chai","doi":"10.1155/2021/6665132","DOIUrl":"https://doi.org/10.1155/2021/6665132","url":null,"abstract":"To accelerate high-intensity heavy-ion beams to high energy in the booster ring (BRing) at the High-Intensity Heavy-Ion Accelerator Facility (HIAF) project, we take the typical reference particle 238U35+, which can be accelerated from an injection energy of 17 MeV/u to the maximal extraction energy of 830 MeV/u, as an example to study the basic processes of longitudinal beam dynamics, including beam capture, acceleration, and bunch merging. The voltage amplitude, the synchronous phase, and the frequency program of the RF system during the operational cycle were given, and the beam properties such as bunch length, momentum spread, longitudinal beam emittance, and beam loss were derived, firstly. Then, the beam properties under different voltage amplitude and synchronous phase errors were also studied, and the results were compared with the cases without any errors. Next, the beam properties with the injection energy fluctuation were also studied. The tolerances of the RF errors and injection energy fluctuation were dictated based on the CISP simulations. Finally, the effect of space charge at the low injection energy with different beam intensities on longitudinal emittance and beam loss was evaluated.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"55 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73966522","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}
Zhaoyang Wu, Weiguo Lu, Enyan Ding, Xiangyang Bao, Zhoubing Yang, F. Song
A compact high-power ultra-wideband bipolar pulse generator based on a modified Marx circuit is designed, which is mainly composed of a primary power supply, Marx generator, sharpening and cutoff subnanosecond spark gap switches, and coaxial transmission lines. The Marx generator with modified circuit structure has thirty-two stages and is composed of eight disk-like modules. Each module consists of four capacitors, two spark gap switches, four charging inductors, and a mechanical support. To simplify the design of the charging structure and reduce the number of switches, four groups of inductors are used to charge the capacitors of the Marx generator, two of which are used for positive voltage charging and the other two for negative voltage charging. When the capacitor of each stage is charged to 35 kV, the maximum output peak voltage can reach 1 MV when the Marx generator is open circuit. The high-voltage pulse generated by the Marx generator charges the transmission line and forms a bipolar pulse through sharpening and cutoff switches. All transmission lines used for bipolar pulse generation have an impedance of 10 Ω. When the 950 kV pulse voltage generated by the Marx generator is fed into the transmission line, the bipolar pulse peak voltage can reach 390 kV, the center frequency of the pulse is about 400 MHz, and the output peak power is about 15.2 GW.
{"title":"A Compact High-Power Ultra-Wideband Bipolar Pulse Generator","authors":"Zhaoyang Wu, Weiguo Lu, Enyan Ding, Xiangyang Bao, Zhoubing Yang, F. Song","doi":"10.1155/2021/2204782","DOIUrl":"https://doi.org/10.1155/2021/2204782","url":null,"abstract":"A compact high-power ultra-wideband bipolar pulse generator based on a modified Marx circuit is designed, which is mainly composed of a primary power supply, Marx generator, sharpening and cutoff subnanosecond spark gap switches, and coaxial transmission lines. The Marx generator with modified circuit structure has thirty-two stages and is composed of eight disk-like modules. Each module consists of four capacitors, two spark gap switches, four charging inductors, and a mechanical support. To simplify the design of the charging structure and reduce the number of switches, four groups of inductors are used to charge the capacitors of the Marx generator, two of which are used for positive voltage charging and the other two for negative voltage charging. When the capacitor of each stage is charged to 35 kV, the maximum output peak voltage can reach 1 MV when the Marx generator is open circuit. The high-voltage pulse generated by the Marx generator charges the transmission line and forms a bipolar pulse through sharpening and cutoff switches. All transmission lines used for bipolar pulse generation have an impedance of 10 Ω. When the 950 kV pulse voltage generated by the Marx generator is fed into the transmission line, the bipolar pulse peak voltage can reach 390 kV, the center frequency of the pulse is about 400 MHz, and the output peak power is about 15.2 GW.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"16 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77249459","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}
Jinyong Fang, Jiangniu Wu, Huijun Huang, Haoliang Zhang, Jing Sun, Jianjun Wang, Li Li
Based on the path encoding pulse compression teleology, a novel method for obtaining high-power microwave (HPM) pulse with ultrahigh repetition frequency is proposed in this paper. The mechanism of the path encoding pulse compression teleology is first introduced. And then, the obtained HPM pulse is analyzed. Theoretical analysis shows that the peak power of MW level and the repetition frequency of MHz level for the generated HPM pulse can be easily reached. To demonstrate the effectiveness of this method for obtaining HPM pulse with ultrahigh repetition frequency characteristic, a HPM-obtaining experiment was carried out based on an S-band microwave source. The HPM pulses with the width of 1 ns, 2 ns, and 3 ns are studied, respectively. The measured results show that the HPM pulse with the power higher than 100 kW and the repetition frequency of 250 kHz at the frequency of 2.856 GHz is easily obtained. The repetition frequency of the generated HPM pulse can be easily changed. Because the pulse with the power higher than 100 kW and the repetition frequency of several hundreds of kHz is obtained for the first time, this type of pulse will have a broad prospect of application in the communication, radar, and electronic countermeasure fields. In addition, the effect experiment of interfering communication and control links was carried out by utilizing the ultrahigh repetition frequency characteristic of the generated HPM pulse. Also, the experiment results show the feasibility of this pulse for interfering the communication and control links.
{"title":"Path Encoding Pulse Compression for Obtaining Novel HPM with Ultrahigh Repetition Frequency","authors":"Jinyong Fang, Jiangniu Wu, Huijun Huang, Haoliang Zhang, Jing Sun, Jianjun Wang, Li Li","doi":"10.1155/2021/3259950","DOIUrl":"https://doi.org/10.1155/2021/3259950","url":null,"abstract":"Based on the path encoding pulse compression teleology, a novel method for obtaining high-power microwave (HPM) pulse with ultrahigh repetition frequency is proposed in this paper. The mechanism of the path encoding pulse compression teleology is first introduced. And then, the obtained HPM pulse is analyzed. Theoretical analysis shows that the peak power of MW level and the repetition frequency of MHz level for the generated HPM pulse can be easily reached. To demonstrate the effectiveness of this method for obtaining HPM pulse with ultrahigh repetition frequency characteristic, a HPM-obtaining experiment was carried out based on an S-band microwave source. The HPM pulses with the width of 1 ns, 2 ns, and 3 ns are studied, respectively. The measured results show that the HPM pulse with the power higher than 100 kW and the repetition frequency of 250 kHz at the frequency of 2.856 GHz is easily obtained. The repetition frequency of the generated HPM pulse can be easily changed. Because the pulse with the power higher than 100 kW and the repetition frequency of several hundreds of kHz is obtained for the first time, this type of pulse will have a broad prospect of application in the communication, radar, and electronic countermeasure fields. In addition, the effect experiment of interfering communication and control links was carried out by utilizing the ultrahigh repetition frequency characteristic of the generated HPM pulse. Also, the experiment results show the feasibility of this pulse for interfering the communication and control links.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"35 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86525766","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}
Huiya Liu, A. Lei, N. Kang, H. An, Zhi-yong Xie, Yao Zhao, Shenlei Zhou, Mingying Sun, B. Zhu, Wei Wang, Jianqiang Zhu
The characterization of energetic protons generated in the ShenGuang-II UP petawatt laser interactions with foil targets has been systematically studied. The proton energy spectra and angular distributions are measured with a radiochromic film stack. It shows that the proton energy spectra have a Boltzmann distribution with temperature of about 2.8 MeV and cutoff energy of about 20 MeV. The divergence angles of protons vary from 10° to 60°, dependent on the proton energy. The proton source size and location are investigated via the proton point-projection mesh imaging. The proton virtual sources are found to locate tens to hundreds of microns in front of the foil target, depending on the proton energies. A Monte Carlo simulation estimates the diameter of the virtual proton source to be about 12 μm for the protons with energy of 16.8 MeV, which is much smaller than the laser focus size of about 50 μm. The spatial resolution of the 16.8 MeV proton imaging is quantified with the point spread function to be about 15 μm, which is consistent with the proton virtual source size. These results will be important for the users conducting experiments with the protons as a backlighting source on the ShenGuang-II UP petawatt laser.
{"title":"Characterization of Energetic Protons Generated in the ShenGuang-II UP Petawatt Laser Interactions with Foil Targets","authors":"Huiya Liu, A. Lei, N. Kang, H. An, Zhi-yong Xie, Yao Zhao, Shenlei Zhou, Mingying Sun, B. Zhu, Wei Wang, Jianqiang Zhu","doi":"10.1155/2021/7205383","DOIUrl":"https://doi.org/10.1155/2021/7205383","url":null,"abstract":"The characterization of energetic protons generated in the ShenGuang-II UP petawatt laser interactions with foil targets has been systematically studied. The proton energy spectra and angular distributions are measured with a radiochromic film stack. It shows that the proton energy spectra have a Boltzmann distribution with temperature of about 2.8 MeV and cutoff energy of about 20 MeV. The divergence angles of protons vary from 10° to 60°, dependent on the proton energy. The proton source size and location are investigated via the proton point-projection mesh imaging. The proton virtual sources are found to locate tens to hundreds of microns in front of the foil target, depending on the proton energies. A Monte Carlo simulation estimates the diameter of the virtual proton source to be about 12 μm for the protons with energy of 16.8 MeV, which is much smaller than the laser focus size of about 50 μm. The spatial resolution of the 16.8 MeV proton imaging is quantified with the point spread function to be about 15 μm, which is consistent with the proton virtual source size. These results will be important for the users conducting experiments with the protons as a backlighting source on the ShenGuang-II UP petawatt laser.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"38 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74120761","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}
D. Raffestin, D. Batani, J. Caron, J. Baggio, G. Boutoux, P. Nicolaï, J. Feugeas, V. Tikhonchuk, E. D'humieres
The advent of high-energy short-pulse laser beams poses new problems related to radiation protection. The radiation generated in experiments using multipetawatt laser systems leads to prompt doses and potentially to the activation of the materials within the interaction chamber and the experimental hall. Despite many new PW laser facilities are nowadays entering into operation, this question has received little attention until now. In this paper, we evaluate the radiological effects induced by the operation of a high-power laser facility. Two working regimes are considered related to the production of hard X-rays and energetic protons. The methodology is general and may be applied for the design of experiments with any high-power laser systems.
{"title":"Modeling of High-Energy Particles and Radiation Production for Multipetawatt Laser Facilities","authors":"D. Raffestin, D. Batani, J. Caron, J. Baggio, G. Boutoux, P. Nicolaï, J. Feugeas, V. Tikhonchuk, E. D'humieres","doi":"10.1155/2021/3355928","DOIUrl":"https://doi.org/10.1155/2021/3355928","url":null,"abstract":"The advent of high-energy short-pulse laser beams poses new problems related to radiation protection. The radiation generated in experiments using multipetawatt laser systems leads to prompt doses and potentially to the activation of the materials within the interaction chamber and the experimental hall. Despite many new PW laser facilities are nowadays entering into operation, this question has received little attention until now. In this paper, we evaluate the radiological effects induced by the operation of a high-power laser facility. Two working regimes are considered related to the production of hard X-rays and energetic protons. The methodology is general and may be applied for the design of experiments with any high-power laser systems.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73336074","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}
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