[FLASH-USERS] laser setup in cylindrical geometry

[Shu Zhang]

Hi Ke, 

After 3D-in-2D projection, the simulation is working like you have a ring of lasers injected at 45 deg. So at the pole, you have higher overlapped intensity, but at the equator, the averaged intensity is lower. This is real when multiple large spot beams are injected at 45 deg. 

-Shu

> On Sep 9, 2020, at 8:32 PM, 方可 <kfang at iphy.ac.cn> wrote:
> 
> Shu:
> 
> 
> 
> Thank you very much for your answer, but i think there is still some problem.  What i mean is when i inject the laser with 45 deg, truly the intensity and energy is not uniform, but i think it should be symmetrically to the 45 degree injection axis.  
> 
> 
> When i use the cartesian geometry without 3Din2D laser setup, the results is symmetrical, but I need run this in cylindrical geometry. I added 2 screenshot of these results of pressure distribution in the mail attachment.
> 
> 
> 
> Thank you for your help! 
> 
>   
> -Ke Fang
> 
> 
> 
> -----原始邮件-----
> 发件人:"Shu Zhang" <shuzhang at princeton.edu>
> 发送时间:2020-09-10 10:56:45 (星期四)
> 收件人: "方可" <kfang at iphy.ac.cn>
> 抄送: "flash-users at flash.uchicago.edu" <flash-users at flash.uchicago.edu>
> 主题: Re: [FLASH-USERS] laser setup in cylindrical geometry
> 
> Hi Ke,
> 
> Your settings are correct. The 3D in 2D laser ray tracing is calculating the laser ray deflection and the energy deposition in 3D and then project the energy deposition on the 2D RZ coordinates. Thus, when the laser is injected in 45 deg, naturally the projected energy deposition is not really uniform. It would look like uniform if you have a planar target normal to the Z(Y) axis. 
> 
> -Shu
> 
>> On Sep 9, 2020, at 7:42 PM, 方可 <kfang at iphy.ac.cn <mailto:kfang at iphy.ac.cn>> wrote:
>> 
>> Hi, everyone:
>> 
>> My simulation is using one laser beam irradiate on a spherical shell, and this laser beam have a 45 degree angle to x-axis. I used the cylindrical geometry, and from the output hdf5 files, I found that the intensity of laser is not symmetrically on the surface of the shell. But when i used the cartesian geometry with same 45 degree incident laser, the intensity on the shell is uniform and symmetrically.
>> 
>> I guess here are some problems when i'm seting up the laser beam. My laser setup in the .par file is as follows:
>> 
>> useEnergyDeposition = .true.
>> ed_maxRayCount      = 20000
>> ed_gradOrder        = 2
>> 
>> # Activate 3D-in-2D ray trace:
>> ed_laser3Din2D           = .true.
>> ed_laser3Din2DwedgeAngle = 0.1
>> 
>> ### LASER IO OPTIONS ###
>> ed_useLaserIO                  = .true.
>> ed_laserIOMaxNumberOfPositions = 10000
>> ed_laserIOMaxNumberOfRays      = 128
>> 
>> ### SETUP LASER PULSES ###
>> ed_numberOfPulses = 1 
>> 
>> # Define Pulse 1:
>> ed_numberOfSections_1 = 4 
>> 
>> ed_time_1_1  = 0.0
>> ed_time_1_2  = 0.01e-09
>> ed_time_1_3  = 0.50e-09
>> ed_time_1_4  = 0.51e-09
>> 
>> ed_power_1_1 = 0.0
>> ed_power_1_2 = 1.52e+012
>> ed_power_1_3 = 1.52e+012
>> ed_power_1_4 = 0.0
>> 
>> 
>> ### SETUP LASER BEAM ###
>> ed_numberOfBeams = 1
>> 
>> # Setup Gaussian Beam:
>> 
>> ed_lensX_1                    =  10.0 
>> ed_lensZ_1                    =  10.0
>> ed_lensY_1                    =  0.0
>> ed_lensSemiAxisMajor_1        =  3.0e-01
>> 
>> ed_targetX_1                  =  212.0e-04
>> ed_targetZ_1                  =  212.0e-04
>> ed_targetY_1                  =  0.0
>> 
>> ed_targetSemiAxisMajor_1      =  225.0e-04
>> ed_targetSemiAxisMinor_1      =  225.0e-04
>> 
>> ed_pulseNumber_1              =  1
>> ed_wavelength_1               =  0.351
>> ed_crossSectionFunctionType_1 = "gaussian2D"
>> ed_gaussianExponent_1         =  4.0
>> ed_gaussianRadiusMajor_1      =  212e-04
>> ed_gaussianRadiusMinor_1      =  212e-04
>> ed_numberOfRays_1             =  4096
>> ed_gridType_1                 = "radial2D"
>> ed_gridnRadialTics_1          =  64
>> ed_semiAxisMajorTorsionAngle_1=  0.0
>> ed_semiAxisMajorTorsionAxis_1 = "x"
>> 
>> 
>> And in mesh parameters:
>> geometry = "cylindrical"  
>> 
>> And, this shell is a hollow spherical shell with outer radius 300 microns and inner radius 150 microns.
>> 
>> So, what should i do to let the intensity of the laser on the shell to be symmetrically to the 45 degree incident axis? 
>> 
>> Thank you for your attention and help !
>> 
>> Best regards,
>> 
>> Ke Fang
>> 
>> phd student
>> Chinese Academy of Sciences
> 
> <45degree_cartesian.PNG><45degree_cylindrical.PNG>

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