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scintillation Arc from FRB 20220912A

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 134-142页

作者： Zi-Wei Wu Robert AMain Wei-Wei Zhu Bing Zhang Peng Jiang Jia-Rui Niu Jin-Lin Han Di Li Ke-Jia Lee Dong-Zi Li Yuan-Pei Yang Fa-Yin Wang Rui Luo Pei Wang Chen-Hui Niu Heng Xu Bo-Jun Wang Wei-Yang Wang Yong-Kun Zhang Yi Feng De-Jiang Zhou Yong-Hua Xu Can-Min Deng Yu-Hao Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Max-Planck-Institut für Radioastronomie Bonn 53121Germany Institute for Frontier in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Nevada Center for Astrophysics and Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy University of Chinese Academy of SciencesBeijing 100049China NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa Department of Astronomy Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Cahill Center for Astronomy and Astrophysics California Institute of TechnologyPasadena 91125USA South-Western Institute For Astronomy Research Yunnan UniversityKunming 650504China School of Astronomy and Space Science Nanjing UniversityNanjing 210093China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210023China CSIRO Space and Astronomy Epping 1710Australia Department of Astronomy School of Physics and Materials ScienceGuangzhou UniversityGuangzhou 510006China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Guangxi Key Laboratory for Relativistic Astrophysics Department of PhysicsGuangxi UniversityNanning 530004China

We present the interstellar scintillation analysis of fast radio burst(FRB)20220912A during its extremely active episode in 2022using data from the Five-hundred-meter Aperture Spherical Radio Telescope(FAST).We detect a scintillation arc in the FRB’s secondary spectrum,which describes the power in terms of the scattered FRB signals’time delay and Doppler shift.The arc indicates that the scintillation is caused by a highly localized region.Our analysis favors a Milky Way origin of the ionized interstellar medium(IISM)for the localized scattering medium but cannot rule out a host galaxy origin.We present our method for detecting the scintillation arc,which can be applied generally to sources with irregularly spaced bursts or pulses.These methods could help shed light on the complex interstellar environment surrounding the FRBs and in our Galaxy.

关键词： fast radio burst scintillation FRB 20220912A

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scintillation and optical properties of Ce-doped YAGG transparent ceramics

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Journal of Rare Earths 2016年第8期34卷 763-768页

作者： Masaki Mori Jian Xu Go Okada Takayuki Yanagida Jumpei Ueda Setsuhisa Tanabe Graduate School of Materials' Science Nara Institute of Science and Technology (NAIST) 8916-5 Takayama-cho Ikoma-shi Nara 630-0192 Japan Graduate School of Human and Environmental Studies Kyoto University Yoshida-nihonmatsu-eho Sakyo-ku Kyoto 606-8501 Japan

We investigated photoluminescence （PL） and scintillation properties of Ce3＋-doped Y3A12Ga3OI2 （Ce：YAGG） trans- parent ceramics synthesized by vacuum sintering with different Ce3＋ concentrations （mol.%） from 0.3% to 1% （0.3%Ce：YAGG, 0.5%Ce：YAGG, 0.8%Ce：YAGG and I%Ce：YAGG）. The samples were synthesized by the vacuum sintering technique. The obtained samples showed a very strong and broad PL emission by the 5dl-4f transition of Ce3＋ in the wavelength range from 470 to 600 nm. The PL decay profiles were approximated by a single exponential decay function with the time constants of around 33-39 ns, Fur- thermore, the scintillation spectra induced by X-rays showed similar features with those observed in PL. The scintillation decay time profiles followed a second-order exponential decay function. The fast component group （ranged 3542 ns） were dominantly contrib- uted by the 5d1-4f transition of Ce3＋. The pulse height spectra utilizing the latter emissions showed a clear photoabsorption peak. Among those samples tested, 0.5%Ce：YAGG sample showed the highest scintillation light yield of 21,400 ph/MeV under 13VCs y-ray irradiation.

关键词： YAGG cerium transparent ceramic scintillation photoluminescence rare earths

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Galactic interstellar scintillation observed from four globular cluster pulsars by FAST

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中国科学:物理学、力学、天文学英文版 2023年第9期66卷 119-127页

作者： Dandan Zhang Zhenzhao Tao Mao Yuan Jumei Yao Pei Wang Qijun Zhi Weiwei Zhu Xun Shi Michael Kramer Di Li Lei Zhang Guangxing Li School of Mathematical Sciences School of Physics and Electronic SciencesGuizhou Normal UniversityGuiyang 550001China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guiyang 550001China Department of Astronomy Beijing Normal UniversityBeijing 100875China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China South-Western Institute for Astronomy Research(SWIFAR) Yunnan UniversityKunming 650000China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Max-Planck Institut fr Radioastronomie Bonn D-53121Germany Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China Computational Astronomy Platform Zhejiang LabHangzhou 311121China

We report detections of scintillation arcs for pulsars in globular clusters M5,M13 and M15 for the first time using the Fivehundred-meter Aperture Spherical radio Telescope(FAST).From observations of these arcs at multiple epochs,we infer that screen-like scattering medium exists at distances 4.1_(-0.3)^(+0.2),6.7_(-0.2)^(+0.2)and 1.3_(-1.0)^(+0.7) kpc from Earth in the directions of M5,M13 and M15,respectively.This means M5's and M13's scattering screens are located at 3.0_(-0.2)^(+0.1) and 4.4_(-0.1)^(+0.1) kpc above the galactic plane,whereas,M15's is at 0.6_(-0.5)^(+0.3) kpc below the plane.We estimate the scintillation timescale and decorrelation bandwidth for each pulsar at each epoch using the one-dimensional auto-correlation in frequency and time of the dynamic spectra.We found that the boundary of the Local Bubble may have caused the scattering of M15,and detected the most distant off-plane scattering screens to date through pulsar scintillation,which provides evidence for understanding the medium circulation in the Milky Way.

关键词： pulsars scintillation globular clusters

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Relationships between ionospheric parameters derived from ionosonde observations and characteristics of post-sunset GHz scintillation during high solar activities(2012−2013)at Sanya(18.3°N,109.6°E),China

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Earth and Planetary Physics 2023年第3期7卷 389-406页

作者： JunJie Luo Ying Xiong WeiHua Luo ZhengPing Zhu ChaoWan Fan College of Electronic and Information Engineering South-Central Minzu University430074 WuhanChina Hubei Key Laboratory of Intelligent Wireless Communications South-Central Minzu University430074 WuhanChina Hubei Engineering Research Center of Intelligent Internet of Things Technology South-Central Minzu University430074 WuhanChina

In this study,we present characteristics of post-sunset GHz scintillation occurrence and their correlations with ionospheric parameters derived from ionosonde observations in high solar activity years(2012−2013)of solar cycle 24 at Sanya(18.3°N,109.6°E;dip lat.:12.8°N),China.The analyzed data include the F_(2)-layer’s critical frequency(foF_(2)),peak height(h_(m)F_(2)),and minimum virtual height(h’F),as well as the scale height around the F_(2)-layer peak(H_(m)),and virtual height(h’F_(5))and true height(hF_(5))measured at 5 MHz.We have investigated relationships between the equinoctial asymmetry of these scintillations and these ionospheric parameters.In addition,we calculate the growth rates of Rayleigh−Taylor instability on the basis of the ionosonde measurements and theoretical models,respectively.We find that the equinoctial asymmetry of scintillation onset time is associated with the scale length of the vertical electron density gradient(L),which has been shown to affect the growth of Rayleigh−Taylor instability at the bottom of the F-layer.The seasonal variations of foF_(2),H_(m)and scale length of vertical electron density gradient appear to cause the seasonal variations of scintillation occurrence;the equinoctial asymmetry of scintillation occurrence rate over low latitudes appears to be related to background electron density and vertical drifts in the F-layer around time of sunset.Further study is required to explain the observed correlational weakness in low latitudes between scintillation strength,represented by the daily maximum S4,and daily maximum values of foF_(2),h_(m)F_(2),h’F,H_(m),and also the drifts.

关键词： equatorial ionosphere scintillation low latitude iononsonde equinoctial asymmetry

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scintillation of partially coherent Gaussian–Schell model beam propagation in slant atmospheric turbulence considering inner- and outer-scale effects

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Chinese Physics B 2014年第7期23卷 409-416页

作者：李亚清吴振森张元元王明军 School of Physics and Optoelectronic Engineering Xidian University School of Physics and Electronic Engineering Xianyang Normal College

Based on the modified Rytov theory and the international telecommunication union-radio （ITU-R） slant atmospheric structure constant model, the uniform scintillation index of partially coherent Gaussian-Schell model （GSM） beam propa- gation in the slant path is derived from weak- to strong-turbulence regions considering inner- and outer-scale effects. The effects of wavelength of beams and inner- and outer-scale of turbulence on scintillation are analyzed numerically. Compar- ison between the scintillation of GSM beams under the von Karman spectrum and that of beams under the modified Hill spectrum is made. The results obtained show that the scintillation index obtained under the von Karman spectrum is smaller than that under the modified Hill spectrum. This study can find theory bases for the experiments of the partially coherent GSM beam propagation through atmospheric turbulence.

关键词： atmospheric turbulence partially coherent beam scintillation atmospheric propagation

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scintillation index of optical wave propagating in turbulent atmosphere

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Chinese Physics B 2009年第2期18卷 581-587页

作者：饶瑞中 Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences

A concise expression of the scintillation index is proposed for a plane optical wave and a spherical optical wave both propagating in a turbulent atmosphere with a zero inner scale and a finite inner scale under an arbitrary fluctuation condition. The expression is based on both the results in the Rytov approximation under a weak fluctuation condition and the numerical results in a strong fluctuation regime. The maximum value of the scintillation index and its corresponding Rytov index are evaluated. These quantities are affected by the ratio of the turbulence inner scale to the Fresnel size.

关键词： atmospheric optics scintillation atmospheric turbulence

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A measure of ionospheric irregularities:zonal velocity and its implications for L-band scintillation at low-latitudes

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Earth and Planetary Physics 2021年第5期5卷 450-461页

作者： Claudio Cesaroni Luca Spogli Giorgiana De Franceschi Juliana Garrido Damaceno Marcin Grzesiak Bruno Vani Joao Francisco Galera Monico Vincenzo Romano Lucilla Alfonsi Massimo Cafaro Istituto Nazionale di Geofisica e Vulcanologia Italy SpacEarth Technology Italy Space Research Centre of the Polish Academy of Sciences Poland Instituto Federal de Educação Ciência e Tecnologia de São PauloBrazil Universidade Estadual Paulista“Júlio de Mesquita Filho” Brazil University of Salento Italy

We estimate the zonal drift velocity of small-scale ionospheric irregularities at low latitude by leveraging the spaced-receivers technique applied to two GNSS receivers for scintillation monitoring installed along the magnetic parallel passing in Presidente Prudente(Brazil,magnetic latitude 12.8°S).The investigated ionospheric sector is ideal to study small-scale irregularities,being located close to the expected position of the southern crest of the equatorial ionospheric anomaly.The measurement campaign took place between September 2013 and February 2014,i.***.equinox and summer solstice seasons under solar maximum,during which the probability of formation of small-scale irregularities is expected to maximize.We found that the hourly average of the velocity increases up to 135 m/s right after the local sunset at ionospheric altitudes and then smoothly decreases in the next hours.Such measurements are in agreement with independent estimations of the velocity made by the Incoherent Scatter Radar located at the Jicamarca Radio Observatory(magnetic latitude 0.1°N),by the Boa Vista Ionosonde(magnetic latitude 12.0°N),and by applying a recently-developed empirical regional short-term forecasting model.Additionally,we investigated the relationship with the percentage occurrence of amplitude scintillation;we report that it is exponentially dependent on the zonal velocity of the irregularities that cause it.

关键词： ionospheric irregularities GNSS scintillation plasma drift velocity low-latitude ionosphere spaced receivers Equatorial Plasma Bubbles

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Optical and scintillation properties of Bi_4Si_3O_(12):RE(RE=Eu^(3+), Sm^(3+),Ho^(3+), Tb^(3+))single crystals

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Journal of Rare Earths 2019年第3期37卷 260-264页

作者： Xuefeng Xiao Jiayue Xu Haicheng Wei Yaoqing Chu Bobo Yang Xuefeng Zhang Key Laboratory of Physics and Photoelectric Information Functional Materials Sciences and Technology North Minzu University College of Electric and Information Engineering North Minzu University School of Materials Science and Engineering Tongji University School of Materials Science and Engineering Shanghai Institute of Technology Ningxia Ju Jing Yuan Crystal Technology Company Limited

Bi_4 Si_3 O_(12):RE(BSO:RE, RE = Eu^(3+), Sm^(3+), Ho^(3+), Tb^(3+)) crystals were grown by the modified vertical Bridgeman method, and doping effects on scintillation properties were investigated. Under γ-ray irradiation, the light yield of BSO doped with small doses of Eu^(3+) increases slightly, and the energy resolution improves significantly compared to pure BSO, therefore the ability of distinguishing between particles will be improved for BSO crystals with a small amount of Eu^(3+) dopant. The results show that a small amount of Eu^(3+) doping can sensitize the Bi^(3+) ions. The sensitization effect enables the reduction of intrinsic defects, and thus improves the scintillation properties. However, the relative light yield of BSO:Tb(1.0 mol%) crystal is 4.3%, which is smaller than 5.0% of pure BSO. The improved light yield and energy resolution in the BSO:Eu and BSO:Sm crystals are considered an impressive achievement in the optimization of this scintillator which is already suitable for applications such as dual-readout calorimeters and homogeneous hadron calorimeters.

关键词： BSO crystal Vertical Bridgeman method scintillation characteristics Relative light yield Rare earths

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Optical and scintillation properties of Nd-doped SrAl2O4 crystals

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Journal of Rare Earths 2016年第8期34卷 757-762页

作者： Daisuke Nakauchi Go Okada Masanori Koshimizu Takayuki Yanagida Graduate School of Materials Science.Nara Institute of Science and Technology(NAIST)8916-5 Takayama-cho lkoma-shiNara 630-0192Japan Department of Applied Chemistry Graduate School of EngineeringTohoku University 6-6-07 AobaAramakiAoba-ku.Sendai 980-8579.Japan

Nd-doped SrA1204 （Nd：SrA1204） crystals were prepared by a floating zone （FZ） method with different dopant concentra- tions. The photoluminescence （PL） measurements under visible light excitations confirmed strong near infrared （NIR） emissions around 890 nm, which is due to the 4f-4f transitions of Nd3＋, and the decay time constants were 300-400 μs. Furthermore, VUV ex- citations revealed two broad emissions around 250450 and 500-700 run, which were attributed to self-trapped excitons （STEs） perturbed by Nd3＋. Moreover, the X-ray induced scintillation spectra showed some small peaks at around 380 nm in addition to NIR emissions at 1064 nm similarly seen in PL. The former scintillation decay time constants were 30-40 Its. In the undoped sample, these emissions mentioned above were not present but a weak broad emission around 450 nm appeared. In thermally stimulated lu- minescence （TSL） after X-ray irradiation, strong TSL glow peaks were observed in the Nd-doped samples at around 100 and 250 ℃.

关键词： scintillation photoluminescence storage luminescence single crystal rare earths

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scintillation Characteristics of Doped PbWO4 Crystals

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Chinese Physics Letters 2001年第4期18卷 513-515页

作者：邵明陈宏芳李澄许彤施朝淑伍健陈辉许咨宗汪兆民汪晓莲邓群殷之文 Department of Modern Physics University of Science and Technology of ChinaHefei 230027 Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050

Emission spectra,longitudinal transmission and light output for the Sb-doped and Y-doped PbWO_(4) crystals are presented.scintillation decay kinetics has been measured by using gate integration and single photon counting method with blue and green filters.Radiation hardness has also been measured by using ^(60)Coγ-ray irradiation under different dose rates and different dose rate profiles.The light yield and radiation hardness of the Sb-doped and Y-doped PbWO_(4) crystals are improved as compared to the undoped crystals and are suitable for the requirements of compact muon solenoid.

关键词： PbWO4 scintillation kinetics

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