{"title":"Suppressing stimulated Raman side-scattering with vector light","authors":"Xiaobao Jia, Q. Jia, R. Yan, Jian Zheng","doi":"10.1063/5.0157811","DOIUrl":"https://doi.org/10.1063/5.0157811","url":null,"abstract":"Recent observations of stimulated Raman side-scattering (SRSS) in different laser inertial confinement fusion ignition schemes have revealed that there is an underlying risk of SRSS on ignition. In this paper, we propose a method that uses the nonuniform nature of the polarization of vector light to suppress SRSS, and we give an additional threshold condition determined by the parameters of the vector light. For SRSS at 90°, where the scattered electromagnetic wave travels perpendicular to the density profile, the variation in polarization of the pump will change the wave vector of the scattered light, thereby reducing the growth length and preventing the scattered electromagnetic wave from growing. This suppression scheme is verified through three-dimensional particle-in-cell simulations. Our illustrative simulation results demonstrate that for linearly polarized Gaussian light, there is a strong SRSS signal in the 90° direction, whereas for vector light, there is very little SRSS signal, even when the conditions significantly exceed the threshold for SRSS. We also discuss the impact of vector light on stimulated Raman backscattering, collective stimulated Brillouin scattering and two-plasmon decay.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"35 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75768114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Xingyu Tang, Xiao Dong, Chunfang Zhang, Kuo Li, Haiyan Zheng, H. Mao
{"title":"Triggering dynamics of acetylene topochemical polymerization","authors":"Xingyu Tang, Xiao Dong, Chunfang Zhang, Kuo Li, Haiyan Zheng, H. Mao","doi":"10.1063/5.0151609","DOIUrl":"https://doi.org/10.1063/5.0151609","url":null,"abstract":"Topochemical reactions are a promising method to obtain crystalline polymeric materials with distance-determined regio- or stereoselectivity. It has been concluded on an empirical basis that the closest intermolecular C⋯C distance in crystals of alkynes, d(C⋯C)min, should reach a threshold of ∼3 Å for bonding to occur at room temperature. To understand this empirical threshold, we study here the polymerization of acetylene in the crystalline state under high pressure by calculating the structural geometry, vibrational modes, and reaction profile. We find d(C⋯C)min to be the sum of an intrinsic threshold of 2.3 Å and a thermal displacement of 0.8 Å (at room temperature). Molecules at the empirical threshold move via several phonon modes to reach the intrinsic threshold, at which the intermolecular electronic interaction is sharply enhanced and bonding commences. A distance–vibration-based reaction picture is thus demonstrated, which provides a basis for the prediction and design of topochemical reactions, as well as an enhanced understanding of the bonding process in solids.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"69 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79681771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Di Peng, Qiaoshi Zeng, Fujun Lan, Zhenfang Xing, Yang Ding, Ho-kwang Mao
{"title":"The near-room-temperature upsurge of electrical resistivity in Lu-H-N is not superconductivity, but a metal-to-poor-conductor transition","authors":"Di Peng, Qiaoshi Zeng, Fujun Lan, Zhenfang Xing, Yang Ding, Ho-kwang Mao","doi":"10.1063/5.0166430","DOIUrl":"https://doi.org/10.1063/5.0166430","url":null,"abstract":"The recent report of superconductivity in nitrogen-doped lutetium hydride (Lu-H-N) at 294 K and 1 GPa brought hope for long-sought-after ambient-condition superconductors. However, the failure of scientists worldwide to independently reproduce these results has cast intense skepticism on this exciting claim. In this work, using a reliable experimental protocol, we synthesized Lu-H-N while minimizing extrinsic influences and reproduced the sudden change in resistance near room temperature. With quantitative comparison of the temperature-dependent resistance between Lu-H-N and the pure lutetium before reaction, we were able to clarify that the drastic resistance change is most likely caused by a metal-to-poor-conductor transition rather than by superconductivity. Herein, we also briefly discuss other issues recently raised in relation to the Lu-H-N system.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134919896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
S. Kojima, T. Miyatake, H. Sakaki, Hiroyoshi Kuroki, Yusuke Shimizu, Hisanori Harada, N. Inoue, T. Dinh, M. Hata, N. Hasegawa, M. Mori, M. Ishino, M. Nishiuchi, K. Kondo, M. Nishikino, M. Kando, T. Shirai, K. Kondo
{"title":"Induction heating for desorption of surface contamination for high-repetition laser-driven carbon-ion acceleration","authors":"S. Kojima, T. Miyatake, H. Sakaki, Hiroyoshi Kuroki, Yusuke Shimizu, Hisanori Harada, N. Inoue, T. Dinh, M. Hata, N. Hasegawa, M. Mori, M. Ishino, M. Nishiuchi, K. Kondo, M. Nishikino, M. Kando, T. Shirai, K. Kondo","doi":"10.1063/5.0153578","DOIUrl":"https://doi.org/10.1063/5.0153578","url":null,"abstract":"This study reports the first experimental demonstration of surface contamination cleaning from a high-repetition supply of thin-tape targets for laser-driven carbon-ion acceleration. The adsorption of contaminants containing protons, mainly water vapor and hydrocarbons, on the surface of materials exposed to low vacuum (>10−3 Pa) suppresses carbon-ion acceleration. The newly developed contamination cleaner heats a 5-μm-thick nickel tape to over 400 °C in 100 ms by induction heating. In the future, this heating method could be scaled to laser-driven carbon-ion acceleration at rates beyond 10 Hz. The contaminant hydrogen is eliminated from the heated nickel surface, and a carbon source layer—derived from the contaminant carbon—is spontaneously formed by the catalytic effect of nickel. The species of ions accelerated from the nickel film heated to various temperatures have been observed experimentally. When the nickel film is heated beyond ∼150 °C, the proton signal considerably decreases, with a remarkable increase in the number and energy of carbon ions. The Langmuir adsorption model adequately explains the temperature dependence of desorption and re-adsorption of the adsorbed molecules on a heated target surface, and the temperature required for proton-free carbon-ion acceleration can be estimated.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"18 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87497109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Qian Wang, Zhi-chao Li, Zhanjun Liu, T. Gong, Wen-shuai Zhang, T. Xu, Bin Li, Ping Li, Xin Li, C. Zheng, L. Cao, Xincheng Liu, K. Pan, Hang Zhao, Yonggang Liu, B. Deng, Lifei Hou, Yingjie Li, Xiangming Liu, Yulong Li, X. Peng, Zanyang Guan, Qiangqiang Wang, X. Che, Sanwei Li, Qiang Yin, Wei Zhang, Liqiong Xia, Peng Wang, Xiaohua Jiang, Liang Guo, Qi Li, M. He, L. Hao, H. Cai, Wudi Zheng, S. Zou, Dong Yang, Feng Wang, Jiamin Yang, Bao-han Zhang, Yongkun Ding, Xiantu He
{"title":"The effects of incident light wavelength difference on the collective stimulated Brillouin scattering in plasmas","authors":"Qian Wang, Zhi-chao Li, Zhanjun Liu, T. Gong, Wen-shuai Zhang, T. Xu, Bin Li, Ping Li, Xin Li, C. Zheng, L. Cao, Xincheng Liu, K. Pan, Hang Zhao, Yonggang Liu, B. Deng, Lifei Hou, Yingjie Li, Xiangming Liu, Yulong Li, X. Peng, Zanyang Guan, Qiangqiang Wang, X. Che, Sanwei Li, Qiang Yin, Wei Zhang, Liqiong Xia, Peng Wang, Xiaohua Jiang, Liang Guo, Qi Li, M. He, L. Hao, H. Cai, Wudi Zheng, S. Zou, Dong Yang, Feng Wang, Jiamin Yang, Bao-han Zhang, Yongkun Ding, Xiantu He","doi":"10.1063/5.0151372","DOIUrl":"https://doi.org/10.1063/5.0151372","url":null,"abstract":"The first laser–plasma interaction experiment using lasers of eight beams grouped into one octad has been conducted on the Shenguang Octopus facility. Although each beam intensity is below its individual threshold for stimulated Brillouin backscattering (SBS), collective behaviors are excited to enhance the octad SBS. In particular, when two-color/cone lasers with wavelength separation 0.3 nm are used, the backward SBS reflectivities show novel behavior in which beams of longer wavelength achieve higher SBS gain. This property of SBS can be attributed to the rotation of the wave vectors of common ion acoustic waves due to the competition of detunings between geometrical angle and wavelength separation. This mechanism is confirmed using massively parallel supercomputer simulations with the three-dimensional laser–plasma interaction code LAP3D.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"107 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78090629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
T. Shelkovenko, I. N. Tilikin, A. Oginov, A. R. Mingaleev, V. Romanova, S. Pikuz
{"title":"Methods of controlled formation of instabilities during the electrical explosion of thin foils","authors":"T. Shelkovenko, I. N. Tilikin, A. Oginov, A. R. Mingaleev, V. Romanova, S. Pikuz","doi":"10.1063/5.0146820","DOIUrl":"https://doi.org/10.1063/5.0146820","url":null,"abstract":"The results of a study of the electrical explosion of aluminum foils with an artificial periodic surface structure created by laser engraving are presented. Experiments were carried out on pulsed high-current generators BIN (270 kA, 300 kV, 100 ns) and KING (200 kA, 40 kV, 200 ns) with Al foil of thicknesses 16 and 4 μm, respectively. Images of the exploded foils were recorded by point projection radiography in the radiation from hybrid X-pinches. It is found that the application of an artificial periodic structure to the foil leads to a much more uniform and well-defined periodic structure of the exploded foil. Images recorded in the UV range using a microchannel-plate-intensified detector show that the radiation from a surface-modified foil is more uniform along the entire length and width of the foil than that from a foil without modification.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"10 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75192106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"The role of charge-exchange processes in probing hydrogen plasma with a heavy ion beam","authors":"I. Tolstikhina, V. P. Shevelko","doi":"10.1063/5.0157170","DOIUrl":"https://doi.org/10.1063/5.0157170","url":null,"abstract":"Charge-changing processes of low-charged ions, used in hydrogen plasma probing by the heavy ion beam probe method, are considered. Along with the ionization of beam ions by plasma electrons and protons, the charge-exchange processes of ions on H atoms and protons are also studied. It is shown that charge exchange of beam ions on plasma protons and H atoms, which is rarely taken into account, plays an important role in beam–plasma interaction. New data on the cross sections and rates of ionization and charge-exchange processes are presented for Tl+ and Tl2+ ions, which are frequently used for plasma diagnostics. Calculations are performed for hydrogen plasma temperatures Te = 1 eV–10 keV and densities Ne = 1012–1014 cm−3 at relatively low and high ion-beam velocities vb = 0.2 and 1.0 a.u., respectively. Special attention is paid to the determination of the electron temperatures at which the charge-exchange processes on H atoms and protons are important. Multiple ionization of beam ions by plasma electrons and protons is briefly discussed.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"11 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86648032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
R. Rossi, M. Gelfusa, T. Craciunescu, L. Spolladore, I. Wyss, E. Peluso, J. Vega, C. Maggi, J. Mailloux, M. Maslov, A. Murari
{"title":"A systematic investigation of radiation collapse for disruption avoidance and prevention on JET tokamak","authors":"R. Rossi, M. Gelfusa, T. Craciunescu, L. Spolladore, I. Wyss, E. Peluso, J. Vega, C. Maggi, J. Mailloux, M. Maslov, A. Murari","doi":"10.1063/5.0143193","DOIUrl":"https://doi.org/10.1063/5.0143193","url":null,"abstract":"To produce fusion reactions efficiently, thermonuclear plasmas have to reach extremely high temperatures, which is incompatible with their coming into contact with material surfaces. Confinement of plasmas using magnetic fields has progressed significantly in the last years, particularly in the tokamak configuration. Unfortunately, all tokamak devices, and particularly metallic ones, are plagued by catastrophic events called disruptions. Many disruptions are preceded by anomalies in the radiation patterns, particularly in ITER-relevant scenarios. These specific forms of radiation emission either directly cause or reveal the approaching collapse of the configuration. Detecting the localization of these radiation anomalies in real time requires an innovative and specific elaboration of bolometric measurements, confirmed by visible cameras and the inversion of sophisticated tomographic algorithms. The information derived from these measurements can be interpreted in terms of local power balances, which suggest a new quantity, the radiated power divided by the plasma internal energy, to determine the criticality of the plasma state. Combined with robust indicators of the temperature profile shape, the identified anomalous radiation patterns allow determination of the sequence of macroscopic events leading to disruptions. A systematic analysis of JET campaigns at high power in deuterium, full tritium, and DT, for a total of almost 2000 discharges, proves the effectiveness of the approach. The warning times are such that, depending on the radiation anomaly and the available actuators, the control system of future devices is expected to provide enough notice to enable deployment of effective prevention and avoidance strategies.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"43 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85418959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Feng Chen, Haibo Xu, Junhui Shi, Xinge Li, Na Zheng
{"title":"A multi-material diagnosis method based on high-energy proton radiography","authors":"Feng Chen, Haibo Xu, Junhui Shi, Xinge Li, Na Zheng","doi":"10.1063/5.0138725","DOIUrl":"https://doi.org/10.1063/5.0138725","url":null,"abstract":"Diagnosis of fluids is extremely significant at high temperatures and high pressures. As an advanced imaging technique, high-energy proton radiography has great potential for application to the diagnosis of high-density fluids. In high-energy proton radiography, an angular collimator can control the proton flux and thus enable material diagnosis and reconstruction of density. In this paper, we propose a multi-material diagnostic method using angular collimators. The method is verified by reconstructing the density distribution from the proton flux obtained via theoretical calculations and numerical simulations. We simulate a 20 GeV proton imaging system using the Geant4 software toolkit and obtain the characteristic parameters of single-material objects. We design several concentric spherical objects to verify the method. We discuss its application to detonation tests. The results show that this method can determine the material and boundary information about each component of a multi-material object. Thus, it can be used to diagnose a mixed material and reconstruct densities in a detonation.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"1 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75201053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Dongdi Zhao, Yongpeng Zhao, Bo An, Jiaqi Li, H. Cui
{"title":"Demonstration of multi-pass amplification of 46.9 nm laser pumped by capillary discharge","authors":"Dongdi Zhao, Yongpeng Zhao, Bo An, Jiaqi Li, H. Cui","doi":"10.1063/5.0150165","DOIUrl":"https://doi.org/10.1063/5.0150165","url":null,"abstract":"Using a plane–plane resonator composed of silicon carbide mirrors, we achieve for the first time multi-pass amplification of a 46.9 nm laser pumped by capillary discharge. In terms of the temporal characteristics, for an initial argon pressure of 17 Pa, triple-pass amplification of the laser is obtained at a delay time between the pre-pulse and the main pulse currents of 40 µs, and quadruple-pass amplification is obtained at a delay time of 50 µs. The experimental results show that the gain duration of the plasma column is more than 6 ns. In terms of spatial characteristics, the spot of the output laser has a reduced full width at half maximum divergence compared with that from a laser without a resonator.","PeriodicalId":54221,"journal":{"name":"Matter and Radiation at Extremes","volume":"1 2","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72608663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}