Pub Date : 2020-07-23DOI: 10.1007/978-3-662-61886-8_2
Juan Pablo Calderón Urbina
{"title":"State of the art","authors":"Juan Pablo Calderón Urbina","doi":"10.1007/978-3-662-61886-8_2","DOIUrl":"https://doi.org/10.1007/978-3-662-61886-8_2","url":null,"abstract":"","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"77 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89215408","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000117
A. Bret, R. Narayan
In a collisionless shock, there are no binary collisions to isotropize the flow. It is therefore reasonable to ask to which extent the magnetohydrodynamics (MHD) jump conditions apply. Following up on recent works which found a significant departure from MHD in the case of parallel collisionless shocks, we here present a model allowing to compute the density jump for collisionless shocks. Because the departure from MHD eventually stems from a sustained downstream anisotropy that the Vlasov equation alone cannot specify, we hypothesize a kinetic history for the plasma, as it crosses the shock front. For simplicity, we deal with non-relativistic pair plasmas. We treat the cases of parallel and perpendicular shocks. Non-MHD behavior is more pronounced for the parallel case where, according to MHD, the field should not affect the shock at all.
{"title":"Density jump for parallel and perpendicular collisionless shocks","authors":"A. Bret, R. Narayan","doi":"10.1017/s0263034620000117","DOIUrl":"https://doi.org/10.1017/s0263034620000117","url":null,"abstract":"In a collisionless shock, there are no binary collisions to isotropize the flow. It is therefore reasonable to ask to which extent the magnetohydrodynamics (MHD) jump conditions apply. Following up on recent works which found a significant departure from MHD in the case of parallel collisionless shocks, we here present a model allowing to compute the density jump for collisionless shocks. Because the departure from MHD eventually stems from a sustained downstream anisotropy that the Vlasov equation alone cannot specify, we hypothesize a kinetic history for the plasma, as it crosses the shock front. For simplicity, we deal with non-relativistic pair plasmas. We treat the cases of parallel and perpendicular shocks. Non-MHD behavior is more pronounced for the parallel case where, according to MHD, the field should not affect the shock at all.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"54 1","pages":"114-120"},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88712607","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000051
Y. Zeng, Chuliang Zhou, R. Qi, Zhongpeng Li, Haiyi Sun, Ye Tian, Jiansheng Liu, Zhi‐zhan Xu
We present the experimental optimization of electrons in the several hundred keV energy range originated from laser-irradiated wire targets. Accelerated by a femtosecond laser pulse, an electron pulse emitted from the wire target was collimated immediately along the wire to a filter unit for the manipulation of energy and spatial distributions. It is shown in simulation that with a pair of magnets as the filter unit, the optimized electrons could serve as a compact and tunable electron source. The proposed system was demonstrated in a proof-of-principle experiment where we attained 1 fC bunch charge with transverse coherence length approaching 1 nm based on a 0.2 TW laser platform. This indicates the scheme as a promising candidate for single-shot electron diffraction.
{"title":"Experimental optimization of the hundred-keV electron source from laser-driven wire target","authors":"Y. Zeng, Chuliang Zhou, R. Qi, Zhongpeng Li, Haiyi Sun, Ye Tian, Jiansheng Liu, Zhi‐zhan Xu","doi":"10.1017/s0263034620000051","DOIUrl":"https://doi.org/10.1017/s0263034620000051","url":null,"abstract":"We present the experimental optimization of electrons in the several hundred keV energy range originated from laser-irradiated wire targets. Accelerated by a femtosecond laser pulse, an electron pulse emitted from the wire target was collimated immediately along the wire to a filter unit for the manipulation of energy and spatial distributions. It is shown in simulation that with a pair of magnets as the filter unit, the optimized electrons could serve as a compact and tunable electron source. The proposed system was demonstrated in a proof-of-principle experiment where we attained 1 fC bunch charge with transverse coherence length approaching 1 nm based on a 0.2 TW laser platform. This indicates the scheme as a promising candidate for single-shot electron diffraction.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"80 1","pages":"94-100"},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78219657","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}
Pub Date : 2020-06-01DOI: 10.1017/s026303462000021x
{"title":"LPB volume 38 issue 2 Cover and Back matter","authors":"","doi":"10.1017/s026303462000021x","DOIUrl":"https://doi.org/10.1017/s026303462000021x","url":null,"abstract":"","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"7 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86360380","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000208
{"title":"LPB volume 38 issue 2 Cover and Front matter","authors":"","doi":"10.1017/s0263034620000208","DOIUrl":"https://doi.org/10.1017/s0263034620000208","url":null,"abstract":"","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"72 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82867655","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000142
F. Tan, Shaolong Wang, Bo Zhang, Z. Zhang, B. Zhu, Yu Chi Wu, Mingyang Yu, Yue Yang, Gang Li, Tiankui Zhang, Yong-hong Yan, F. Lu, W. Fan, Wei Zhou, Y. Gu
In this paper, the generation of relativistic electron mirrors (REMs) and the reflection of an ultra-short laser off this mirrors are discussed, applying two-dimensional particle-in-cell (2D-PIC) simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapidly expanding. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads the resonance between laser and REM. The reflected radiation near this interval and the corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, certain part of the reflected field could be selectively amplified or depressed, leading to the selectively adjusting of the corresponding spectra.
{"title":"Selective amplification of the chirped attosecond pulses produced from relativistic electron mirrors","authors":"F. Tan, Shaolong Wang, Bo Zhang, Z. Zhang, B. Zhu, Yu Chi Wu, Mingyang Yu, Yue Yang, Gang Li, Tiankui Zhang, Yong-hong Yan, F. Lu, W. Fan, Wei Zhou, Y. Gu","doi":"10.1017/s0263034620000142","DOIUrl":"https://doi.org/10.1017/s0263034620000142","url":null,"abstract":"In this paper, the generation of relativistic electron mirrors (REMs) and the reflection of an ultra-short laser off this mirrors are discussed, applying two-dimensional particle-in-cell (2D-PIC) simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapidly expanding. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads the resonance between laser and REM. The reflected radiation near this interval and the corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, certain part of the reflected field could be selectively amplified or depressed, leading to the selectively adjusting of the corresponding spectra.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"60 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80561513","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000063
Saurabh Kumar, D. N. Gupta
The energy of protons accelerated by ultra-intense lasers in the target normal sheath acceleration (TNSA) mechanism can be greatly enhanced by the laser parameter optimization. We propose to investigate the optimization of laser parameters for proton acceleration using double laser pulses in TNSA mechanism. The sheath field generation at the rear side of the target is significantly affected by the introduction of second laser pulse in TNSA mechanism, and consequently, the energy of the accelerated protons is also modified. The second laser pulse was introduced with different delays to study its impact on proton acceleration. Our study shows that the interplay of laser intensity and pulse duration of both laser pulses affects the proton acceleration. It was found that the proton maximum energy is the function of both laser intensity and pulse duration. A number of simulations have been performed to obtain maximum proton energy data under different combinations of laser intensity and pulse duration for the two laser pulses. The simulation results account for the underline physics for the proton bunch energy and the sheath field as a function of pulse intensity and pulse delay.
{"title":"Optimization of laser parameters for proton acceleration using double laser pulses in TNSA mechanism","authors":"Saurabh Kumar, D. N. Gupta","doi":"10.1017/s0263034620000063","DOIUrl":"https://doi.org/10.1017/s0263034620000063","url":null,"abstract":"The energy of protons accelerated by ultra-intense lasers in the target normal sheath acceleration (TNSA) mechanism can be greatly enhanced by the laser parameter optimization. We propose to investigate the optimization of laser parameters for proton acceleration using double laser pulses in TNSA mechanism. The sheath field generation at the rear side of the target is significantly affected by the introduction of second laser pulse in TNSA mechanism, and consequently, the energy of the accelerated protons is also modified. The second laser pulse was introduced with different delays to study its impact on proton acceleration. Our study shows that the interplay of laser intensity and pulse duration of both laser pulses affects the proton acceleration. It was found that the proton maximum energy is the function of both laser intensity and pulse duration. A number of simulations have been performed to obtain maximum proton energy data under different combinations of laser intensity and pulse duration for the two laser pulses. The simulation results account for the underline physics for the proton bunch energy and the sheath field as a function of pulse intensity and pulse delay.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"74 1","pages":"73-78"},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73215864","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000105
S. Lugomer
We study dynamics, structure and organization of the new paradigm of wavewrinkle structures associated with multipulse laser-induced RayleighTaylor (RT) instability in the plane of a target surface in the circumferential zone ( C -zone) of the spot. Irregular target surface, variation of the fluid layer thickness and of the fluid velocity affect the nonlinearity and dispersion. The fluid layer inhomogeneity establishes local domains arranged (organized) in the «domain network». The traveling wavewrinkles become solitary waves and latter on become transformed into stationary soliton wavewrinkle patterns. Their morphology varies in the radial direction ofaussian-like spot ranging from the compacton-like solitons to the aperiodic rectangular waves (with rounded top surface) and to the periodic ones. These wavewrinkles may be successfully juxtapositioned with the exact solution of the nonlinear differential equations formulated in the KadomtsevPetviashvili sense taking into account the fluid conditions in particular domain. The cooling wave that starts at the periphery by the end of the pulse causes sudden increase of density and surface tension: the wavewrinkle structures become unstable what causes their break-up. The onset of solidification causes formation of an elastic sheet which starts to shrink generating lateral tension on the wavewrinkles. The focusing of energy at the constrained boundary causes the formation of wrinklons as the new elementary excitation of the elastic sheets.
{"title":"Nano-wrinkles, compactons, and wrinklons associated with laser-induced Rayleigh–Taylor instability: I. Bubble environment","authors":"S. Lugomer","doi":"10.1017/s0263034620000105","DOIUrl":"https://doi.org/10.1017/s0263034620000105","url":null,"abstract":"We study dynamics, structure and organization of the new paradigm of wavewrinkle structures associated with multipulse laser-induced RayleighTaylor (RT) instability in the plane of a target surface in the circumferential zone ( C -zone) of the spot. Irregular target surface, variation of the fluid layer thickness and of the fluid velocity affect the nonlinearity and dispersion. The fluid layer inhomogeneity establishes local domains arranged (organized) in the «domain network». The traveling wavewrinkles become solitary waves and latter on become transformed into stationary soliton wavewrinkle patterns. Their morphology varies in the radial direction ofaussian-like spot ranging from the compacton-like solitons to the aperiodic rectangular waves (with rounded top surface) and to the periodic ones. These wavewrinkles may be successfully juxtapositioned with the exact solution of the nonlinear differential equations formulated in the KadomtsevPetviashvili sense taking into account the fluid conditions in particular domain. The cooling wave that starts at the periphery by the end of the pulse causes sudden increase of density and surface tension: the wavewrinkle structures become unstable what causes their break-up. The onset of solidification causes formation of an elastic sheet which starts to shrink generating lateral tension on the wavewrinkles. The focusing of energy at the constrained boundary causes the formation of wrinklons as the new elementary excitation of the elastic sheets.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"50 12 1","pages":"101-113"},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83399912","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}
Pub Date : 2020-06-01DOI: 10.1017/s026303462000004x
Zul Irfan, S. Bashir, S. Butt, Asma Hayat, R. Ayub, K. Mahmood, M. Akram, Amna Batool
The plasma parameters of laser-ablated Zirconium (Zr) using a Langmuir probe technique have been investigated by employing a Q-switched Nd:YAG laser (532 nm, 6 ns) at various irradiances ranging from 8.6 to 15.5 GW/cm 2 . All the measurements have been performed under an ultra-high vacuum condition while keeping the probe at a fixed distance of 4 mm from the target. By varying the biasing voltages from 1 to 75 V, the corresponding values of electric currents are measured by the probe on the oscilloscope. Laser-induced Zr plasma parameters such as electron temperature, electron number density, plasma potential, Debye length, and thermal velocity have been evaluated from I–V characteristic curves of Langmuir probe data. It is found that both the electron temperature and thermal velocity of Zr plasma reveal an increasing trend from 18 to 41 eV and 2.8 × 10 8 to 4.3 × 10 8 cm/s, respectively, with increasing laser irradiance which is attributed to more energy deposition and enhanced ablation rate. However, the electron number density of Zr plasma exhibits a non-significant increase from 6.5 × 10 14 to 6.7 × 10 14 cm −3 with increasing irradiance from 8.6 to 10.9 GW/cm 2 . A further increase in irradiance from 12 to 15.5 GW/cm 2 causes a reduction in the number density of Zr plasma from 6.1 × 10 14 to 5.6 × 10 14 cm −3 which is attributed to the formation of thick sheath, ambipolar electric field, and laser-supported detonation waves (Shock front). Scanning electron microscope analysis has been performed to reveal the surface morphology of irradiated Zr. It reveals the formation of cracks, ridges, cones, and grains. It was observed at high irradiances the ridges are vanished, whereas cones and cracks are dominant features. By controlling plasma parameters, surface structuring of materials can be controlled, which has a vast range of applications in the industry and medicine.
{"title":"Evaluation of electron temperature and electron density of laser-ablated Zr plasma by Langmuir probe characterization and its correlation with surface modifications","authors":"Zul Irfan, S. Bashir, S. Butt, Asma Hayat, R. Ayub, K. Mahmood, M. Akram, Amna Batool","doi":"10.1017/s026303462000004x","DOIUrl":"https://doi.org/10.1017/s026303462000004x","url":null,"abstract":"The plasma parameters of laser-ablated Zirconium (Zr) using a Langmuir probe technique have been investigated by employing a Q-switched Nd:YAG laser (532 nm, 6 ns) at various irradiances ranging from 8.6 to 15.5 GW/cm 2 . All the measurements have been performed under an ultra-high vacuum condition while keeping the probe at a fixed distance of 4 mm from the target. By varying the biasing voltages from 1 to 75 V, the corresponding values of electric currents are measured by the probe on the oscilloscope. Laser-induced Zr plasma parameters such as electron temperature, electron number density, plasma potential, Debye length, and thermal velocity have been evaluated from I–V characteristic curves of Langmuir probe data. It is found that both the electron temperature and thermal velocity of Zr plasma reveal an increasing trend from 18 to 41 eV and 2.8 × 10 8 to 4.3 × 10 8 cm/s, respectively, with increasing laser irradiance which is attributed to more energy deposition and enhanced ablation rate. However, the electron number density of Zr plasma exhibits a non-significant increase from 6.5 × 10 14 to 6.7 × 10 14 cm −3 with increasing irradiance from 8.6 to 10.9 GW/cm 2 . A further increase in irradiance from 12 to 15.5 GW/cm 2 causes a reduction in the number density of Zr plasma from 6.1 × 10 14 to 5.6 × 10 14 cm −3 which is attributed to the formation of thick sheath, ambipolar electric field, and laser-supported detonation waves (Shock front). Scanning electron microscope analysis has been performed to reveal the surface morphology of irradiated Zr. It reveals the formation of cracks, ridges, cones, and grains. It was observed at high irradiances the ridges are vanished, whereas cones and cracks are dominant features. By controlling plasma parameters, surface structuring of materials can be controlled, which has a vast range of applications in the industry and medicine.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"58 1","pages":"84-93"},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83462241","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}
Pub Date : 2020-06-01DOI: 10.1017/s0263034620000038
Ram Jeet, Asheel Kumar
Electron dynamics in an axially localized large amplitude electron Bernstein mode in a magnetic mirror is studied. The mode is localized due to plasma density and magnetic field profiles and could be driven by an electron cyclotron wave, launched from outside, via linear mode conversion. Energetic electrons of finite gyro-radius resonantly interact with the mode and gain primarily transverse energy favoring stronger mirror confinement. At Bernstein wave normalized amplitude of A00 = 0.01 and for other normalized parameters Zn0 = 40, k⊥c/ω = 10, ${L}^{prime}_m = 215$, ωc0/ω = 0.9, ψn0 = 3π/2, the electrons can gain energy in the hundreds of keV range.
{"title":"Bernstein mode acceleration of electrons in a magnetic mirror","authors":"Ram Jeet, Asheel Kumar","doi":"10.1017/s0263034620000038","DOIUrl":"https://doi.org/10.1017/s0263034620000038","url":null,"abstract":"Electron dynamics in an axially localized large amplitude electron Bernstein mode in a magnetic mirror is studied. The mode is localized due to plasma density and magnetic field profiles and could be driven by an electron cyclotron wave, launched from outside, via linear mode conversion. Energetic electrons of finite gyro-radius resonantly interact with the mode and gain primarily transverse energy favoring stronger mirror confinement. At Bernstein wave normalized amplitude of A00 = 0.01 and for other normalized parameters Zn0 = 40, k⊥c/ω = 10, ${L}^{prime}_m = 215$, ωc0/ω = 0.9, ψn0 = 3π/2, the electrons can gain energy in the hundreds of keV range.","PeriodicalId":49925,"journal":{"name":"Laser and Particle Beams","volume":"3 1","pages":"79-83"},"PeriodicalIF":0.9,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81594854","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}