• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Prompt acceleration of a μ+ beam in a toroidal wakefield driven by a shaped steeprising-front Laguerre-Gaussian laser pulse

    2022-06-01 07:56:18XiaonanWANG王曉南XiaofeiLAN蘭小飛YongshengHUANG黃永盛YougeJIANG蔣又歌
    Plasma Science and Technology 2022年5期
    關(guān)鍵詞:張昊春雷

    Xiaonan WANG (王曉南), Xiaofei LAN (蘭小飛),*,Yongsheng HUANG (黃永盛), Youge JIANG (蔣又歌),

    Chunlei ZHANG (張春雷)2, Hao ZHANG (張昊)5 and Tongpu YU (余同普)5

    1 School of Physics and Astronomy,China West Normal University,Nanchong 637009,People's Republic of China

    2 Key Laboratory of Beam Technology of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China

    3 School of Science,Shenzhen Campus of Sun Yat-sen University,Shenzhen 518107,People's Republic of China

    4 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China

    5 Department of Physics, National University of Defense Technology, Changsha 410073, People's Republic of China

    Abstract Recent experimental data for anomalous magnetic moments strongly indicates the existence of new physics beyond the Standard Model.Energetic μ+ bunches are relevant to μ+ rare decay,spin rotation, resonance and relaxation (μSR) technology, future muon colliders, and neutrino factories.In this paper, we propose prompt μ+ acceleration in a nonlinear toroidal wakefield driven by a shaped steep-rising-front Laguerre-Gaussian (LG) laser pulse.An analytical model is described,which shows that a μ+beam can be focused by an electron cylinder at the centerline of a toroidal bubble and accelerated by the front part of the longitudinal wakefield.A shaped LG laser with a short rise time can push plasma electrons,generating a higher-density electron sheath at the front of the bubble,which can enhance the acceleration field.The acceleration field driven by the shaped steep-rising-front LG laser pulse is about four times greater than that driven by a normal LG laser pulse.Our simulation results show that a 300 MeV μ+bunch can be accelerated to 2 GeV and its transverse size is focused from an initial value of w0=5 μm to w=2 μm in the toroidal bubble driven by the shaped steep-rising-front LG laser pulse with a normalized amplitude of a=22.

    Keywords: plasma wakefield acceleration, muon source, laser shaping

    1.Introduction

    Recently,there has been increasing interest in the exploration of new physics beyond the Standard Model using the μ+rare decay[1-3]and the anomalous magnetic moment[4-6].The unstable particle, μ+(μ-) with a rest mass mμ=207meand a rest lifetime τ=2.2 μs has been applied in many fields(meis the rest mass of the electron).Energetic μ+(μ-) bunches can be used to make future neutrino factories [7, 8] and muon colliders[9,10]become a reality.In the field of spin rotation,resonance, and relaxation (μSR) technology [11-14], an energetic μ+beam can pass through the wall of a container toprobe materials in complex environments.The two available types of μ+(μ-)are low-flux GeV cosmic muons[15,16]and low-energy muon sources produced by traditional accelerators[17-19].The cosmic muons are too low-flux and the muon sources produced by traditional accelerators are too shortlived to explore new physics.

    Plasma-based accelerators [20-23] can offer extremely high acceleration fields of several hundred GV/m and can be applied to the study of high-energy physics and particle sources.Recently, a μ-beam was accelerated to GeV or 10 GeV in a plasma wakefield [24, 25].However, the acceleration of a μ+beam in a laser plasma wakefield has not been explored.A μ+beam would be defocused by the transverse field in a regular bubble driven by a Gaussian laser pulse.

    Using three-dimensional (3D) particle-in-cell (PIC)simulations performed by Epoch3D [26], we propose a prompt μ+acceleration scheme in a nonlinear toroidal wakefield [27-29] driven by a shaped Laguerre-Gaussian(LG) laser pulse [30].A collimated muon bunch with a peak energy of several hundred MeV was recently produced by a GeV electron beam interacting with a high-Z target [31, 32].In our simulations, we focus on μ+acceleration and assume that the required μ+beam has been injected into the wakefield.An analytical model is given, which shows that a μ+beam can be focused by an electron cylinder at the centerline of the toroidal bubble and accelerated in the front part of the longitudinal wakefield Ex.The simulation results show that in the wakefield driven by a LG laser pulse, the transverse size of the μ+beam is focused from an initial value of w0=5 μm to w=2 μm within several picoseconds.In addition,the peak energy of the accelerated μ+bunch, which had an initial energy of 300 MeV, is about 500 MeV.A LG laser pulse shaped by a near-critical-density plasma has a shorter rise time.The shaped steep-rising-front LG laser pushes plasma electrons forward, causing an electron sheath with largerσe≡nshΔxnshto be formed at the front of the toroidal bubble,where nshandΔxnshare the density and width of the electron sheath, respectively.The acceleration field Exis proportional to σe.The simulation results show that in the toroidal wakefield driven by a shaped steep-rising-front LG laser, the peak energy of the accelerated μ+bunch with an initial energy of 300 MeV is about 2 GeV, and the transverse size of the μ+bunch is also focused from an initial value of w0=5 μm to w=2 μm within several picoseconds.

    In cylindrical coordinates, the transverse distribution of the normalized amplitude of an LG laser can be expressed as:

    where a0is the maximum normalized amplitude, cl,pis the normalizing factor, w is the laser spot size, andis the generalized Laguerre polynomial.In our simulations, the Gaussian model of the laser pulse used is the LG1,0model,which can be expressed as:

    where c1,0≈1.67w.Equation (2) shows that the laser intensity at r=0 is zero.Due to the ponderomotive force of the LG laser pulse, plasma electrons are squeezed into the center axis and form an electron cylinder.This center electron cylinder has a higher density than that of the background electrons.The ponderomotive force of the LG laser pulse can also exclude nearby plasma electrons.Plasma protons can be considered as unmovable.The homogeneous protons pull the excluded electrons back to the center axis.Therefore, a toroidal bubble is formed.

    A μ+beam can be accelerated and focused in a nonlinear toroidal wakefield [33, 34] driven by an LG laser pulse.Figure 1(a) shows a transverse density slice of a toroidal bubble.The red arrow in figure 1(a) shows the direction of the transverse electric field produced by the central electron cylinder.The transverse electric field of the central electron cylinder forms a focusing field for the μ+beam.In figure 1(b),negative momentum means that the central electrons are moving in the negative x direction.Therefore, their magnetic field is a focusing field.The toroidal wakefields shown in figures 1(c), (e) were driven by the same LG laser pulse at different plasma densities of ne=5×1024m-3and ne=1×1025m-3, and look like two spherical bubbles.Figure 1(c)shows that in a nonlinear scheme, the two spherical wakefields have overlapping ranges.Figure 1(d)shows that the longitudinal wakefield Exhardly varies with r,i.e.?Ex/?r ?0.Figure 1(e)shows that at the onset of the nonlinear scheme, the two spherical wakefields have no overlap.The longitudinal wakefield Exis close to zero at r=0, as shown in figure 1(f).Only the nonlinear toroidal wakefield can accelerate and focus the μ+beam.

    Figure 1.Simulation results illustrating focusing (a), (b) and acceleration (c), (d) fields for a μ+ beam in a nonlinear toroidal wakefield.(a)shows a transverse slice of the toroidal wakefield as shown in(c)at x=60 μm.(b)shows plots of the momentum in the x direction of the electrons and μ+at the centerline of the toroidal wakefield.(c)shows a longitudinal slice of the electron density at z=0 μm in a plasma with a density of ne=5×1024 m-3.(d) shows the longitudinal wakefield Ex corresponding to (c).(e) shows a longitudinal slice of the toroidal wakefield at z=0 μm in a plasma with a higher density of ne=1×1025 m-3.(f) shows the Ex corresponding to (e).

    2.A physical model

    We propose a simple physical model shown in figure 2 to illustrate the focusing and accelerating of the μ+beam in the nonlinear toroidal wakefield driven by a LG laser.The blue arrows is the direction of the focusing force.The red arrow is the direction of the longitudinal wakefield.nshis the density of the electron sheath at the front of the wakefield.Δxnshis the width of this electron sheath.The σeis defined asσe≡nshΔxnsh.The longitudinal wakefield Exis equal to zero at x=0, x0.For 0 <x <x1, the longitudinal wakefield Exis the acceleration field for positive particles.In the range of 0 <x <x1, y <y1and y >y0, the plasma electron density is close to zero.The electron cylinder at the centerline of the toroidal provides the focusing force for positive particles and the electron sheath at the front of the toroidal provides the acceleration field.In the wakefield coordinate, the acceleration field can be considered as a static electric field.The acceleration field in the wakefield coordinate is equal to that in the laboratory coordinate.The Gauss’s law for the static electric field can be expressed as:

    Figure 2.A physical model of the focusing and accelerating of a μ+beam in a toroidal wakefield driven by a LG laser pulse.The physical model is in the range of the red dotted line as shown in(c).The center red rectangle represents the center electron cylinder.The right red rectangle represents the electron sheath at the front of the toroidal wakefield.

    where ∮sis the integral of the closed surface S,is the electric field,q is the charge inner the closed surface S,ε0is the vacuum permittivity.The six surfaces of the blue cuboid form the closed surfaceS=s1+s1′ +s2+s2′ +s3+s3′.We assume that s1ands1′are infinitesimal,which causes the electric field on s2and s3almost equal to that ons2′ands3′,respectively.The electric field ons1′ is equal to zero.Therefore in the range of 0 <x <x0, y <y1and y >y0, the acceleration field on s1can be expressed as:

    where neis the electron density,npis the proton density and considered as a constant, e is the elementary charge.It is assumed that the density of the electron sheath at the front of the toroidal is a constant nsh.The σeis defined asσe≡nshΔxnsh.In the range of 0 <x <x0, y <y1and y >y0,the acceleration field Excan be simplified as:

    equation (5) shows that for a given position on the x-axis,the acceleration field Exis proportional to σe.

    3.Three-dimensional simulations of the μ+acceleration in a toroidal wakefield driven by a LG laser pulse

    We implement PIC simulations to explore the focusing and accelerating of a μ+beam in a toroidal wakefield driven by a LG laser pulse.Those simulation results as shown in figure 3 are obtained using a LG laser with the spot size, w=15 μm, normalized amplitude, a0=22, and pulse width, τ=25 fs.At the beginning of the simulation, a 300 MeV μ+beam is placed at the front part of the acceleration field where the LG laser pulse also exists as shown in figures 3(a) and (g).Compared with positrons,μ+has a slower response to the oscillating field of the LG laser pulse.Therefore,the μ+beam and the LG laser pulse can be placed at the same position in the toroidal wakfield,which ensures that the μ+beam can be accelerated with a longer acceleration length.Detailed simulation parameters are shown in configuration A of table 1.The Gauss(x, x0, w) function as shown in table 1 calculate a Gaussian profile in variable x centred on x0with a characteristic width w and be expressed as:

    The snapshots shown in figure 3 are taken at the beginning, middle, and end of the acceleration, corresponding to simulation times of t=0.2 ps, t=2.0 ps, and t=5.0 ps.Figures 3(a)-(c) show that an LG laser pulse can be selfguided,which is attributed to the distribution of the refractive index at the front of the toroidal wakefield.Figures 3(d)-(f)show that the toroidal wakefield propagates stably within 5 ps, and provides continuous acceleration and focusing fields for the μ+beam.The acceleration field is separated at five picoseconds, since the central electron cylinder retroacts on the LG laser pulse.Figures 3(g)-(i) show that the transverse size of the μ+bunch is focused from a value of w0=5 μm to w=2 μm within several picoseconds by the central electron cylinder.During the acceleration process the μ+bunch always moves back toward the rear edge of the toroidal wakefield and finally enters the decelerating field at five picoseconds.The final peak energy of the μ+beam is about 500 MeV.The energy spread iswhere △E is the full width at half maximum (FWHM) and E is the peak energy.

    Figure 3.The μ+acceleration in a toroidal wakefield driven by a LG laser pulse.(a)-(i)show the longitudinal slices of the simulation box at the plane of z=0 μm.(a)-(c)show the evolution of the laser pulse.(d)-(f)show the longitudinal structure of the toroidal wakefield.(g)-(i)show the longitudinal wakefield Ex and the density of the μ+ bunch.(j)-(l) are the energy spectrum of the μ+ bunch.

    4.The stronger acceleration field driven by a shaped steep-rising-front LG laser for positive particle

    Table 1.Detailed simulation parameters for three configurations:(A),(B),and(C).We only list the parameters of configurations B and C that differ from those of configuration A.

    The shaping of a Gaussian laser pulse was proposed by H W Wang and coworkers [35].They demonstrate that as relativistic self-focusing (RSF) [36, 37], relativistic self-phase modulation (RSPM) [38, 39], and relativistic transparency occur in the interaction between a laser pulse and a nearcritical plasma,three shaping effects take place:laser intensity enhancement, laser profile steepening, and absorption of the nonrelativistic prepulse.Our simulation results show that an LG laser pulse can also be shaped by a near-critical plasma.The shaping effect is controlled by the length of the nearcritical plasma.Figure 4 shows the transverse oscillating electric fields of LG laser pulses shaped by near-criticaldensity plasmas with lengths of 1 μm, 5 μm and 10 μm,respectively.The rise time of the shaped LG laser pulse shown in figure 4(a) is longer compared with that of the shaped LG laser pulse shown in figure 4(b), which limits the maximum transversal wakefield driven by this shaped LG laser pulse.Figure 4(c) shows that if the length of the nearcritical plasma is 10 μm, the maximum amount of LG laser pulse energy is consumed by the near-critical plasma.Therefore, in our simulations, the length of the near-critical plasma is set to 5 μm.Figure 5 shows the influences of the shaping of the LG laser pulse and the plasma density on the acceleration field.The simulation results in figures 5(a), (b),and (c) are obtained using the parameters shown in configurations A, B, and C, respectively.Compared with the blue line in figure 5(a), the blue line in figure 5(b) shows that the electron sheath generated by the shaped laser pulse has a larger σe.Furthermore,the blue line in figure 5(c)shows that in a higher-density plasma, σeis larger.Corresponding to those black lines,the red lines in figure 5 show the theoretical results of equation(5).The electron density neof equation(5)is represented by the blue lines.The theoretical results agree with the simulation results.The red line in figure 5(c) shows that in a higher-density plasma, the acceleration field driven by a shaped steep-rising-front LG laser is the largest and can reach about 2.4 TV/m.

    Figure 4.Comparison of LG laser pulses shaped by near-critical-density plasmas with different lengths: 1 μm, 5 μm, and 10 μm.Figures 4(a)-(c) are all one-dimensional simulation results located at y=0 μm, z=10 μm in the three-dimensional simulation box.

    Figure 5.Comparison of the wakefields driven by an LG laser pulse (a) and a shaped LG laser pulse (b)-(c), illustrating that the shaped steep-rising-front LG laser can stimulate a higher acceleration gradient.The blue lines represent the simulated results for the electron density.The black and red lines represent the simulated and theoretical results for the acceleration field Ex.The blue and black lines are located at y=0 μm, z=10 μm in the three-dimensional simulation box.

    5.Three-dimensional simulations of μ+ acceleration in a toroidal wakefield driven by a shaped steeprising-front LG laser pulse

    Figure 6 shows the evolution of the μ+acceleration process in a toroidal wakefield driven by a shaped steep-rising-front LG laser.The laser parameters are the same as those of figure 3.A μ+bunch with an initial energy of 300 MeV can be located at the front part of the wakefield by adjusting its injection time.The detailed simulation parameters are listed in configuration C of table 1.Figure 6 shows that in a plasma with a density of ne=1×1025m-3, a shaped steep-rising-front LG laser pulse can drive the acceleration field at the centerline of the toroidal bubble for positive particles.Although the central electron cylinder is unstable during acceleration, the transverse size of the μ+beam is also focused.The snapshots shown in figure 6 are taken at the beginning, middle, and end of the acceleration corresponding to simulation times of t=0.1 ps, t=1.5 ps,and t=3.0 ps.Figure 6(a) shows that an LG laser pulse is shaped by a near-critical-density plasma.The shaped LG laser has a shorter rise time of tr=13 fs and a higher amplitude of Ey=5×1013V/m,compared to the LG laser shown in figure 3(a) with a rise time of tr=33 fs and an amplitude of Ey=4×1013V/m.Figures 6(b)and(c)show that the LG laser pulse is self-guided.A large proportion of the laser energy is depleted at t=3 ps.Figures 6(e),(f),(h),and (i) show that the acceleration field is stable within 3 ps and at up to 4×1012V/m.Figures 6(g)-(i) show that the transverse size of the μ+bunch is focused from the initial value of w0=5 μm to w=2 μm within several picoseconds by the central electron cylinder.At the beginning of the acceleration,the μ+bunch with an initial energy of 300 MeV moves backward relative to the toroidal bubble and is simultaneously accelerated.When the velocity of the μ+bunch is larger than that of the toroidal wakefield,it moves forward relative to the toroidal bubble and finally overtakes the acceleration field.In the toroidal wakefield driven by a shaped steep-rising-front LG laser pulse, the final peak energy of an accelerated μ+bunch with an initial energy of 300 MeV is about 2 GeV.The energy spread is

    Figure 6.The acceleration process of a μ+ beam in a toroidal wakefield driven by a shaped steep-rising-front LG laser pulse.(a)-(i) show longitudinal slices of the simulation box at the plane z=0 μm.The scaling factor for (d) is ×10.The scaling factor for the other figures is×1.(a)shows the shaping of an LG laser pulse in a near-critical-density plasma.(b),(c)show the evolution of the laser pulse.(d)shows the density distribution of a near-critical-density plasma.(e), (f) show the longitudinal structure of a toroidal bubble.(g) shows the initial density distribution of the μ+beam.(h),(i)show the longitudinal field Ex and the density distribution of the μ+beam.(j)-(l)show the energy spectrum of the μ+ beam.

    6.Comparison of the peak energies of the accelerated muon beam for three different simulation configurations

    Figure 7 mainly shows the influences of the shaping of the LG laser pulse and the plasma density on the peak energy of the accelerated μ+bunch.The circles, triangles, and squares represent simulation times of 3 ps,4.5 ps,and 5 ps,using the simulation parameters shown in configurations(A),(B),and(C)of table 1,respectively.For the red circles shown in figure 7,the maximum LG laser pulse energy was consumed at a simulation time of t=3 ps.When the initial energy is 100 MeV, most muons cannot catch up with the focusing and acceleration fields.With an initial energy increase from 100 MeV to 300 MeV, the peak energy and number of muons in the accelerated μ+bunch both increase.When the initial energy increases from 300 MeV to 450 MeV, the number of muons still increases, but the peak energy decreases; the reason for this is that with a higher initial energy,the μ+bunch overtakes the wakefield earlier and has a shorter acceleration time.For the green triangles, the wakefield collapsed at the simulated time of t=4.5 ps.When the initial energy is increased, the peak energy and the number of muons in the accelerated μ+bunch also both increase.For the blue squares, the wakefield collapsed at a simulated time of t=5 ps.When the initial energy is increased, the peak energy of the accelerated μ+bunch increases and the number of muons almost remains constant due to the stable focusing field driven by a normal LG laser pulse.Compared with the blue solid line shown in figure 7, the red solid line shows that in the toroidal wakefield driven by a shaped steep-rising-front LG laser pulse, the peak energy of the μ+beam can be increased by three to four times compared to that of a μ+beam accelerated in a toroidal wakefield driven by a normal LG laser pulse.

    Figure 7.The initial energy E0 of the μ+ bunch versus the peak energy Eacc and the total number of muons after the μ+ bunch is accelerated.The solid lines represent the peak energy Eacc of the accelerated μ+bunch.The y error bars only represent the FWHM of the energy spectrums.The dashed lines represent the total number of the muons at the corresponding moment.

    7.Discussion

    We also considered the synchronization of the laser and muon beam.In PIC simulations, synchronization can be realized by controlling the injection times of the laser and the muon beam.However, in experiments, the synchronization will be very complicated.Here, we propose the preliminary time control system as shown in figure 8 to realize synchronization.We assume that the time of muon beam injection into the plasma accelerator from the muon source,tμ,is fixed.The time of the laser pulse injection into the plasma accelerator is modulated by the distance between the upper and lower mirrors, L, as shown in figure 8.When L is changed by 0.15 μm, the timing of the laser pulse injected into the plasma accelerator is altered by 1 fs.The main difficulty in realizing the synchronization is finding a way to precisely confirm tμ, which will be included in our next work plan.

    Figure 8.A preliminary time control system to realize the synchronization of the laser and muon beam.Here, tμ is the time at which the muon beam is injected into the plasma accelerator by the muon source.L is the distance between the upper and lower mirrors.The time control system is in the blue dotted box.

    8.Conclusions

    In conclusion, based on our PIC simulations, we propose an analytical physical model to illustrate the acceleration and focusing of μ+bunches in a donut wakefield driven by a LG laser or a shaped steep-rising-front LG laser.The transverse electric field and the magnetic field of the central electron cylinder are both focusing fields for positive particles.The acceleration field Exis proportional to the σeof the pushed electron sheath at the front of the donut bubble.An LG laser pulse can be shaped by a near-critical-density plasma.A shaped LG laser pulse with a shorter rise time can push plasma electrons,generating a electron sheath with a larger σeat the front of the donut bubble.A donut bubble driven by an LG laser can provide a stable focusing field but a lower acceleration field.The acceleration field driven by a shaped steep-rising-front LG laser pulse is four times higher than that driven by an unshaped LG laser pulse.Although the central electron cylinder generated by a shaped LG laser pulse is unstable during the acceleration process,the transverse size of the μ+beam is also focused.The μ+beam is accelerated from 300 MeV to 2 GeV in the donut wakefield driven by a shaped steep-rising-front LG laser pulse with a normalized amplitude of a=22.In 2017,a laser pulse with a wavelength of 800 nm,an output energy of 300 J,a maximum peak power of 10 PW and a pulse width of 21 fs was obtained at the Shanghai Superintense Ultrafast Laser Facility[40],which supports the feasibility of the compact prompt acceleration scheme.This new compact prompt acceleration scheme for μ+beams will provide higher-energy muon sources than those of traditional accelerators.An energetic μ+source will be an attractive way to realize future muon colliders and neutrino factories and has the potential to unlock new physics beyond the Standard Model.

    Acknowledgments

    Our work was supported in part by the National Key R&D Program of China (No.2018YFA0404802), National Natural Science Foundation of China (No.11 875 319), the Hunan Provincial Science and Technology Program (No.2020RC4020), Innovation Project of IHEP (Nos.542 017IHEPZZBS11820, 542 018IHEPZZBS12427), the CAS Center for Excellence in Particle Physics (CCEPP), the Meritocracy Research Funds of China West Normal University (No.17YC504).

    ORCID iDs

    猜你喜歡
    張昊春雷
    春雷響
    幼兒100(2024年11期)2024-03-27 08:32:56
    Quantum correlation enhanced bound of the information exclusion principle
    惜物
    做人與處世(2022年2期)2022-05-26 22:34:53
    花事
    愛情順風車
    一道考題
    My Dream Weekends
    豐 碑
    春雷
    春雷乍響活驚蟄
    久久精品久久精品一区二区三区| 男女免费视频国产| 精品酒店卫生间| 亚洲成人国产一区在线观看 | 最近的中文字幕免费完整| 99久国产av精品国产电影| 大片免费播放器 马上看| 精品国产国语对白av| 五月天丁香电影| 曰老女人黄片| 水蜜桃什么品种好| 久久久久精品性色| 日韩 亚洲 欧美在线| 一二三四在线观看免费中文在| 99久国产av精品国产电影| 丝袜脚勾引网站| 午夜福利影视在线免费观看| 啦啦啦啦在线视频资源| 亚洲三区欧美一区| 丰满饥渴人妻一区二区三| 一级黄片播放器| 亚洲成人一二三区av| 欧美亚洲日本最大视频资源| 在线亚洲精品国产二区图片欧美| 成年av动漫网址| 国产深夜福利视频在线观看| 欧美亚洲日本最大视频资源| 女人被躁到高潮嗷嗷叫费观| 亚洲精品在线美女| 悠悠久久av| 久久久久久久大尺度免费视频| 亚洲精品一区蜜桃| 丝袜喷水一区| 久久久欧美国产精品| 亚洲成av片中文字幕在线观看| 宅男免费午夜| 在线天堂中文资源库| 99精国产麻豆久久婷婷| 高清黄色对白视频在线免费看| 一级片免费观看大全| 最近最新中文字幕大全免费视频 | 久久99一区二区三区| 色精品久久人妻99蜜桃| 欧美亚洲 丝袜 人妻 在线| 99香蕉大伊视频| 国产精品秋霞免费鲁丝片| 欧美日韩福利视频一区二区| 亚洲美女视频黄频| 可以免费在线观看a视频的电影网站 | 别揉我奶头~嗯~啊~动态视频 | 久久久久久久久免费视频了| 欧美久久黑人一区二区| 久久久精品94久久精品| 久久人人爽av亚洲精品天堂| 国产人伦9x9x在线观看| 成人影院久久| 啦啦啦视频在线资源免费观看| 亚洲欧美清纯卡通| 少妇人妻精品综合一区二区| 亚洲精品中文字幕在线视频| 成年动漫av网址| 19禁男女啪啪无遮挡网站| 国产成人精品久久久久久| 成人毛片60女人毛片免费| 中文欧美无线码| 免费不卡黄色视频| 亚洲欧洲精品一区二区精品久久久 | 免费久久久久久久精品成人欧美视频| 日本猛色少妇xxxxx猛交久久| 9色porny在线观看| 99久久综合免费| 日韩 亚洲 欧美在线| 飞空精品影院首页| 久久久久久人人人人人| av在线app专区| 国产伦理片在线播放av一区| 成人免费观看视频高清| 中文天堂在线官网| 91aial.com中文字幕在线观看| 桃花免费在线播放| 色吧在线观看| 久久久国产一区二区| 两个人看的免费小视频| 午夜福利视频精品| 国产片特级美女逼逼视频| 亚洲av综合色区一区| 高清在线视频一区二区三区| 久久天堂一区二区三区四区| av有码第一页| 最近中文字幕2019免费版| 国产一区二区三区av在线| 国产一区亚洲一区在线观看| 我的亚洲天堂| 国产老妇伦熟女老妇高清| 18禁观看日本| 亚洲人成网站在线观看播放| 人体艺术视频欧美日本| 亚洲熟女精品中文字幕| 性少妇av在线| 国产精品一区二区在线不卡| 精品卡一卡二卡四卡免费| 日本欧美国产在线视频| 国产成人欧美| 一个人免费看片子| 欧美黄色片欧美黄色片| 国产男女超爽视频在线观看| av网站免费在线观看视频| 亚洲av成人精品一二三区| 日韩av免费高清视频| 欧美日韩视频高清一区二区三区二| 久久久久久久久免费视频了| 你懂的网址亚洲精品在线观看| 午夜久久久在线观看| 亚洲精品av麻豆狂野| 午夜久久久在线观看| 桃花免费在线播放| 亚洲综合色网址| 国产一区二区 视频在线| 大片免费播放器 马上看| 黄色视频在线播放观看不卡| 丝袜在线中文字幕| 日韩 欧美 亚洲 中文字幕| 午夜福利一区二区在线看| 午夜福利免费观看在线| 一级毛片黄色毛片免费观看视频| 国产福利在线免费观看视频| 99热国产这里只有精品6| 女人精品久久久久毛片| 亚洲情色 制服丝袜| 亚洲成人手机| 精品久久久精品久久久| 精品少妇内射三级| 精品久久久精品久久久| 欧美日韩国产mv在线观看视频| 亚洲精品成人av观看孕妇| 国产亚洲精品第一综合不卡| 99re6热这里在线精品视频| 亚洲一码二码三码区别大吗| 国产极品粉嫩免费观看在线| 免费久久久久久久精品成人欧美视频| 久久99热这里只频精品6学生| 欧美国产精品va在线观看不卡| 婷婷成人精品国产| 久久婷婷青草| 国产精品.久久久| 亚洲av中文av极速乱| 视频区图区小说| 欧美精品av麻豆av| 国产 精品1| 亚洲精品一区蜜桃| 亚洲男人天堂网一区| 人成视频在线观看免费观看| 极品人妻少妇av视频| 日韩人妻精品一区2区三区| 极品人妻少妇av视频| 欧美日韩视频高清一区二区三区二| 欧美国产精品va在线观看不卡| 亚洲精品一区蜜桃| 国产成人精品福利久久| 成人黄色视频免费在线看| 成人影院久久| 亚洲欧美精品综合一区二区三区| 天天影视国产精品| 午夜福利免费观看在线| 久久性视频一级片| 一级毛片电影观看| 欧美人与性动交α欧美软件| 国产成人欧美| 国产成人一区二区在线| 精品福利永久在线观看| 国产精品秋霞免费鲁丝片| 在线观看国产h片| 婷婷色综合www| 久久精品国产a三级三级三级| 国产在线视频一区二区| 亚洲精品视频女| 亚洲伊人久久精品综合| 国产成人av激情在线播放| 国产片特级美女逼逼视频| 韩国精品一区二区三区| 午夜福利,免费看| 亚洲第一区二区三区不卡| 别揉我奶头~嗯~啊~动态视频 | 19禁男女啪啪无遮挡网站| 男女边摸边吃奶| 午夜激情久久久久久久| 国产成人a∨麻豆精品| 丝袜脚勾引网站| 99久久人妻综合| 亚洲欧美成人精品一区二区| 啦啦啦 在线观看视频| 一级毛片黄色毛片免费观看视频| 欧美日韩视频精品一区| 日本猛色少妇xxxxx猛交久久| 咕卡用的链子| 久久久久久免费高清国产稀缺| 欧美精品高潮呻吟av久久| 日韩,欧美,国产一区二区三区| 51午夜福利影视在线观看| 男人操女人黄网站| 熟女少妇亚洲综合色aaa.| 中文字幕av电影在线播放| 国产精品一区二区精品视频观看| 老熟女久久久| 赤兔流量卡办理| 欧美日韩一区二区视频在线观看视频在线| 91aial.com中文字幕在线观看| 国产精品免费大片| 大片免费播放器 马上看| 啦啦啦啦在线视频资源| 欧美av亚洲av综合av国产av | 亚洲伊人久久精品综合| 精品少妇久久久久久888优播| 无限看片的www在线观看| 久热爱精品视频在线9| 新久久久久国产一级毛片| 男女床上黄色一级片免费看| 亚洲av日韩在线播放| 人人妻人人澡人人看| 国产精品女同一区二区软件| 最近2019中文字幕mv第一页| 天天影视国产精品| 久久精品人人爽人人爽视色| 久久99精品国语久久久| 午夜激情久久久久久久| 亚洲精品国产av成人精品| 人人妻,人人澡人人爽秒播 | 麻豆乱淫一区二区| 欧美成人午夜精品| 另类亚洲欧美激情| 欧美日韩成人在线一区二区| 欧美少妇被猛烈插入视频| 九色亚洲精品在线播放| 国产精品麻豆人妻色哟哟久久| 精品免费久久久久久久清纯 | 久久久国产精品麻豆| 婷婷色综合大香蕉| 精品第一国产精品| 天堂俺去俺来也www色官网| 80岁老熟妇乱子伦牲交| 人成视频在线观看免费观看| xxx大片免费视频| 国产精品熟女久久久久浪| 丁香六月天网| 天天添夜夜摸| 少妇被粗大猛烈的视频| 天美传媒精品一区二区| 久久久久久免费高清国产稀缺| 亚洲国产精品999| 国产黄色免费在线视频| 男女高潮啪啪啪动态图| 青春草国产在线视频| 尾随美女入室| 欧美精品一区二区免费开放| 日韩成人av中文字幕在线观看| 国产精品久久久久久精品古装| 欧美黑人欧美精品刺激| 欧美日韩视频精品一区| 久久久久久久久免费视频了| 老汉色∧v一级毛片| 在线精品无人区一区二区三| 91aial.com中文字幕在线观看| 久久人人爽av亚洲精品天堂| 亚洲精品国产区一区二| 国产成人一区二区在线| 国产 一区精品| 久久97久久精品| 亚洲国产精品国产精品| 人体艺术视频欧美日本| 亚洲精品乱久久久久久| 国产av国产精品国产| 久久久久久久国产电影| 性高湖久久久久久久久免费观看| 日韩精品有码人妻一区| 午夜91福利影院| 男女午夜视频在线观看| 五月开心婷婷网| 色吧在线观看| 五月天丁香电影| 成人午夜精彩视频在线观看| 亚洲精品视频女| 精品一区二区三区av网在线观看 | 99久久99久久久精品蜜桃| 亚洲国产精品国产精品| 国产熟女欧美一区二区| 七月丁香在线播放| 欧美国产精品va在线观看不卡| 国产色婷婷99| 伊人亚洲综合成人网| www.熟女人妻精品国产| 国产黄色视频一区二区在线观看| 国产又色又爽无遮挡免| 国产精品一国产av| 啦啦啦在线免费观看视频4| 伊人久久国产一区二区| 天堂中文最新版在线下载| 中文精品一卡2卡3卡4更新| 五月天丁香电影| 蜜桃在线观看..| 国产精品一国产av| 99久久99久久久精品蜜桃| 国产免费又黄又爽又色| 成人手机av| 国产1区2区3区精品| 国产野战对白在线观看| 人成视频在线观看免费观看| 国产一区二区 视频在线| 欧美亚洲日本最大视频资源| 九草在线视频观看| 亚洲欧洲国产日韩| 中文字幕精品免费在线观看视频| 日韩视频在线欧美| 久久天躁狠狠躁夜夜2o2o | 日日摸夜夜添夜夜爱| 伊人久久国产一区二区| 精品国产乱码久久久久久男人| xxx大片免费视频| 曰老女人黄片| 欧美黑人欧美精品刺激| 精品国产乱码久久久久久小说| 亚洲婷婷狠狠爱综合网| 天天影视国产精品| 视频在线观看一区二区三区| 91老司机精品| 国产深夜福利视频在线观看| 国产伦人伦偷精品视频| 日韩av免费高清视频| 啦啦啦啦在线视频资源| 国产成人一区二区在线| 操出白浆在线播放| 国产熟女午夜一区二区三区| 国产一区二区 视频在线| 韩国精品一区二区三区| 免费女性裸体啪啪无遮挡网站| 国产片内射在线| 三上悠亚av全集在线观看| 天天添夜夜摸| 亚洲国产精品一区三区| 日韩制服丝袜自拍偷拍| 国产伦人伦偷精品视频| 制服人妻中文乱码| 老司机靠b影院| 美女脱内裤让男人舔精品视频| 午夜久久久在线观看| 免费看av在线观看网站| 大香蕉久久网| 啦啦啦在线观看免费高清www| 久热爱精品视频在线9| 十八禁网站网址无遮挡| 精品一区二区免费观看| av女优亚洲男人天堂| 亚洲,欧美精品.| 菩萨蛮人人尽说江南好唐韦庄| 99久国产av精品国产电影| 亚洲视频免费观看视频| 日韩伦理黄色片| 超碰成人久久| 国产一卡二卡三卡精品 | 97人妻天天添夜夜摸| 亚洲国产精品999| 精品一区二区三区四区五区乱码 | 青春草亚洲视频在线观看| 如何舔出高潮| 国产av码专区亚洲av| 黑人猛操日本美女一级片| 女人被躁到高潮嗷嗷叫费观| 亚洲第一区二区三区不卡| 美女扒开内裤让男人捅视频| 亚洲精品国产av蜜桃| 男的添女的下面高潮视频| 久久97久久精品| 秋霞伦理黄片| 人人妻人人澡人人看| 一二三四在线观看免费中文在| 五月开心婷婷网| 亚洲欧洲精品一区二区精品久久久 | 又黄又粗又硬又大视频| 亚洲视频免费观看视频| av福利片在线| 老司机亚洲免费影院| a级片在线免费高清观看视频| 午夜老司机福利片| 色婷婷久久久亚洲欧美| 亚洲成av片中文字幕在线观看| 爱豆传媒免费全集在线观看| 精品少妇一区二区三区视频日本电影 | 亚洲,欧美,日韩| 一级毛片 在线播放| 国产亚洲av高清不卡| 国产精品一区二区在线观看99| 国产男女内射视频| 三上悠亚av全集在线观看| 电影成人av| 亚洲国产欧美网| 久热这里只有精品99| 日韩精品有码人妻一区| 免费黄色在线免费观看| 大陆偷拍与自拍| 中国国产av一级| 免费黄频网站在线观看国产| 中文欧美无线码| 欧美人与性动交α欧美软件| 老汉色av国产亚洲站长工具| 亚洲国产欧美在线一区| 中文字幕亚洲精品专区| 婷婷色麻豆天堂久久| 国产1区2区3区精品| 精品一品国产午夜福利视频| 操出白浆在线播放| 亚洲欧美一区二区三区国产| 亚洲av电影在线进入| 国产亚洲最大av| 免费黄频网站在线观看国产| 国产熟女午夜一区二区三区| av女优亚洲男人天堂| 一级毛片黄色毛片免费观看视频| 天美传媒精品一区二区| h视频一区二区三区| 桃花免费在线播放| 亚洲精品国产区一区二| 人成视频在线观看免费观看| 久久99热这里只频精品6学生| 青春草视频在线免费观看| 日韩制服骚丝袜av| 国产无遮挡羞羞视频在线观看| 男女免费视频国产| 卡戴珊不雅视频在线播放| 1024香蕉在线观看| 国产亚洲欧美精品永久| 亚洲图色成人| 国产精品无大码| 欧美日韩精品网址| 亚洲第一区二区三区不卡| 黄色怎么调成土黄色| 两个人免费观看高清视频| 国产成人91sexporn| 亚洲av综合色区一区| 午夜福利网站1000一区二区三区| av卡一久久| 捣出白浆h1v1| 成人影院久久| 国产日韩欧美在线精品| 国产一区二区在线观看av| 悠悠久久av| 亚洲av中文av极速乱| 老司机影院成人| 成人亚洲精品一区在线观看| 国产精品女同一区二区软件| 少妇被粗大的猛进出69影院| 成人国产av品久久久| 久久久久久免费高清国产稀缺| 久久人妻熟女aⅴ| av卡一久久| 国产精品二区激情视频| 国产片内射在线| 少妇精品久久久久久久| 免费不卡黄色视频| 久久久久久人妻| 久久性视频一级片| 国产乱来视频区| 亚洲精品自拍成人| 亚洲一区中文字幕在线| 天天添夜夜摸| 国产免费视频播放在线视频| 亚洲精品视频女| 成人国语在线视频| 成年av动漫网址| 如日韩欧美国产精品一区二区三区| 97人妻天天添夜夜摸| 欧美激情高清一区二区三区 | 人人妻人人爽人人添夜夜欢视频| 中文精品一卡2卡3卡4更新| 精品亚洲成国产av| 精品国产一区二区久久| 国产精品蜜桃在线观看| 国产精品国产三级专区第一集| 久久精品亚洲熟妇少妇任你| 亚洲av日韩精品久久久久久密 | 久久久精品国产亚洲av高清涩受| 黄网站色视频无遮挡免费观看| 国产女主播在线喷水免费视频网站| 王馨瑶露胸无遮挡在线观看| 欧美黄色片欧美黄色片| 欧美另类一区| 久久精品aⅴ一区二区三区四区| 久久久久国产一级毛片高清牌| 亚洲图色成人| 国产欧美日韩综合在线一区二区| 热re99久久精品国产66热6| 啦啦啦 在线观看视频| 精品第一国产精品| 宅男免费午夜| 国产成人啪精品午夜网站| 国产日韩欧美在线精品| 国产男人的电影天堂91| 一个人免费看片子| 国产精品亚洲av一区麻豆 | 亚洲av成人精品一二三区| 黄色 视频免费看| 91aial.com中文字幕在线观看| 久久人人爽人人片av| 久久久亚洲精品成人影院| 久久久久网色| 亚洲七黄色美女视频| 无限看片的www在线观看| 亚洲成人av在线免费| av在线播放精品| 亚洲精品美女久久久久99蜜臀 | 嫩草影院入口| 日韩熟女老妇一区二区性免费视频| 国精品久久久久久国模美| 亚洲成av片中文字幕在线观看| 欧美另类一区| 欧美97在线视频| 99热网站在线观看| 97在线人人人人妻| 久久久久精品久久久久真实原创| 国产精品熟女久久久久浪| 精品酒店卫生间| 国产1区2区3区精品| 两个人免费观看高清视频| 在线观看免费午夜福利视频| 国产无遮挡羞羞视频在线观看| 亚洲美女黄色视频免费看| 韩国高清视频一区二区三区| 18在线观看网站| 韩国av在线不卡| 只有这里有精品99| 妹子高潮喷水视频| 街头女战士在线观看网站| 热re99久久精品国产66热6| 亚洲人成电影观看| 韩国av在线不卡| 街头女战士在线观看网站| 在线观看www视频免费| 欧美精品一区二区免费开放| 亚洲精品在线美女| 欧美人与性动交α欧美精品济南到| 晚上一个人看的免费电影| 美女主播在线视频| 纯流量卡能插随身wifi吗| 少妇人妻 视频| 涩涩av久久男人的天堂| 色吧在线观看| 久久国产精品男人的天堂亚洲| 国产男人的电影天堂91| 日韩 欧美 亚洲 中文字幕| 国产精品免费大片| 久热这里只有精品99| 久久影院123| 99re6热这里在线精品视频| 人人妻人人添人人爽欧美一区卜| 在线天堂中文资源库| 久久热在线av| 午夜免费男女啪啪视频观看| 国产男女内射视频| 日韩欧美一区视频在线观看| 2018国产大陆天天弄谢| 一区福利在线观看| 男女国产视频网站| 免费看不卡的av| 久久人人爽av亚洲精品天堂| 亚洲,欧美,日韩| 91精品国产国语对白视频| 色网站视频免费| 国产精品熟女久久久久浪| 亚洲国产欧美一区二区综合| 欧美日韩av久久| 亚洲精品,欧美精品| 飞空精品影院首页| 男人操女人黄网站| 天天躁夜夜躁狠狠躁躁| 亚洲伊人久久精品综合| 免费黄频网站在线观看国产| 中文精品一卡2卡3卡4更新| 久久精品aⅴ一区二区三区四区| 精品一区在线观看国产| 国产毛片在线视频| 欧美日韩视频高清一区二区三区二| 久久久久精品人妻al黑| 日本爱情动作片www.在线观看| 久久久国产精品麻豆| 一本久久精品| 国产成人精品无人区| 久热爱精品视频在线9| 91aial.com中文字幕在线观看| 18禁动态无遮挡网站| 色婷婷av一区二区三区视频| 亚洲欧美色中文字幕在线| 亚洲国产中文字幕在线视频| 尾随美女入室| 高清不卡的av网站| 国产高清不卡午夜福利| 一本大道久久a久久精品| 电影成人av| 国产亚洲av高清不卡| 成人黄色视频免费在线看| 晚上一个人看的免费电影| 久久久精品国产亚洲av高清涩受| 欧美av亚洲av综合av国产av | 国产成人系列免费观看| 国产男女内射视频| 亚洲成人国产一区在线观看 | 99久久综合免费| 中文字幕另类日韩欧美亚洲嫩草| 黄色视频在线播放观看不卡| 麻豆av在线久日| 欧美成人精品欧美一级黄| 国产成人91sexporn| 国产xxxxx性猛交| 搡老乐熟女国产| 久久久国产精品麻豆| 免费在线观看视频国产中文字幕亚洲 | 午夜久久久在线观看| 黄片小视频在线播放|