loasis4.inp

pic 模拟程序！面向对象

loasis4.inp
{

Here we make an initial attempt to model the effects of small-scale
variations in the neutral gas density, and how it might be impacting
the laser plasma experiments in the l'OASIS laboratory of Wim Leemans
et al. at LBNL.

Pulse with transverse Gaussian profile and y polarization is launched from
the left boundary. 

Cartesian geometry, no plasma initially, background of neutral H gas.

This is derived from loasis2.inp -- here we turn off the moving window
and run the laser pulse through a saw-shaped density profile.
}

Variables
{
// General numerical parameters
  PI = 3.14159

// **********************************************************************
// General physical parameters
// **********************************************************************
  electronMass = 9.1094e-31 
  electronCharge = -1.6022e-19
  permit = 8.8542e-12 
  speedLight = 2.9979e8
  speedLight2 = speedLight*speedLight 
  electronCharge2 = electronCharge*electronCharge 
  qOverM = electronCharge/electronMass

  ionCharge = -electronCharge
  unitMassMKS = electronMass / 5.48579903e-04
  hydrogenMassNum = 1.00797
  hydrogenMass = unitMassMKS * hydrogenMassNum

// **********************************************************************
// Plasma parameters
// **********************************************************************
//   Here, we have zero initial plasma density.
  elecPlasmaDensity =  0.0 
  elecPlasmaFreq = sqrt(electronCharge*qOverM*elecPlasmaDensity/permit)
 
// **********************************************************************
// Laser pulse parameters - y polarization
// **********************************************************************
//   We are modeling a laser pulse with wavelength of 0.8 micron and
//   FHWM pulse length of 50 fs to 200 fs, and a peak intensity of
//   10^14 to 10^15 W/cm^2
//
  peakLaserIntensity = 1e+16  // W/cm^2
  pulseLengthFWHM = 50.e-15
  laserWavelength = 0.8e-06
  laserFrequency = 2.*PI*speedLight/laserWavelength
  // We must convert the intensity to MKS units
  peakLaserIntensityMKS = peakLaserIntensity * 1.0e+04
  peakElectricField = sqrt(2.*peakLaserIntensityMKS/speedLight/permit)

// **********************************************************************
// Grid parameters
// **********************************************************************
// We must resolve the laser wavelength
  Nx = 512
  Ny = 256
  numGridsPerWavelength = 16
  dx = laserWavelength / numGridsPerWavelength
  gridSizeRatio = 10
  dy = dx * gridSizeRatio
  Lx = Nx * dx
  Ly = Ny * dy

  d = 1. / sqrt( 1./(dx*dx) + 1./(dy*dy) )
  timeStep = 0.7 * d / speedLight

// **********************************************************************
// More laser parameters:
// **********************************************************************
// We model the laser pulse envelope as a Gaussian (nPulseShape=1).
  nPulseShape = 1
  pulseLength  = pulseLengthFWHM * speedLight

// Here we specify the waist size, Rayleigh length, etc.
// These parameters are for a pulse with y-polarization.
  waistSize = 6.0e-06 
  angFreq = laserFrequency
  angFreq2 = angFreq * angFreq
  waveVector = sqrt( (angFreq2-elecPlasmaFreq*elecPlasmaFreq) / speedLight2 )
  rayleighLength = waistSize * waistSize * waveVector / 2.
  waistLocation = 3.0 * rayleighLength

// **********************************************************************
// Define gas density, pressure and other MCC parameters
// **********************************************************************
  gasTempEV       = 1.0e-06  // make gas cold (cannot set temperature to zero)
  gasDensityMKS   = 2.e25
  gasPressureTorr = 1.20e-21 * gasDensityMKS * gasTempEV

  nRamp1 = Nx / 2
  nRamp2 = Nx / 2
  offSet = 0.5 * dx
  xRamp1 = offSet + nRamp1 * dx
  xRamp2 = xRamp1 + nRamp2 * dx
}

Region
{
Grid
{
  J = Nx 
  x1s = 0.0
  x1f = Lx 
  n1 = 1.0 
  K = Ny 
  x2s = 0.0
  x2f = Ly 
  n2 = 1.0
  Geometry = 1
}

Control
{
  dt = timeStep
}

Species
{
  name = electrons
  m = electronMass 
  q = electronCharge 
  particleLimit = 2.5e+05 // prevents out-of-control growth in # of ptcls
}

Species
{
  name = ions
  m = hydrogenMass
  q = ionCharge
// -- you can't subcycle the ions, because they are moved by the high-frequency
//    oscillations of the laser pulse
//  subcycle = 20
  particleLimit = 1.0e+05 // prevents out-of-control growth in # of ptcls
}

// Specify the Monte Carlo collision parameters for background gas
MCC
{
  gas                         = H
  pressure                    = gasPressureTorr
  temperature                 = gasTempEV

  analyticF = gasDensityMKS * ( ramp(x1/xRamp1)*step(xRamp1-x1) + (1.-ramp((x1-xRamp1)/(xRamp2-xRamp1)))*step(xRamp2-x1)*step(x1-xRamp1) )

  // to discard the ngd data from the dump file set 
  // discardDumpFileNGDDataFlag to a nonzero int value
  // discardDumpFileNGDDataFlag = 1

  eSpecies                    = electrons
  iSpecies                    = ions
 
  // turn OFF electron/ion collisions, including impact ionization
  collisionFlag = 0

  // turn on tunneling ionization in linearly polarized alternating field
  tunnelingIonizationFlag     = 1       
  // specify static field / circular polarization
  ETIPolarizationFlag         = 1
  // fix the number of macro particles to be created in each cell
  TI_numMacroParticlesPerCell = 8
}
Diagnostic
{
	j1 = 0
	j2 = Nx
	k1 = 0
	k2 = Ny
	VarName = WaveDirDiagnostic
        polarizationEB = EzBy
        psd1dFlag = 1 // calculate the 1d power spectral density
        windowName = Blackman
	title = Wave Energy
	x1_Label = x
	x2_Label = y
	x3_Label = Wave Energy
}
PortGauss
{
  j1 = 0 
  k1 = 0 
  j2 = 0 
  k2 = Ny 
  normal = 1

  A = 0
  C = 1.0 

// Wave (0)
  pulShp_p0 = nPulseShape
  tdelay_p0 = 0.0 
  pulLeng_p0 = pulseLength
  chirp_p0 = 0.0
  spotSize_p0 = waistSize
  waveLeng_p0 = laserWavelength
  focus_p0 = waistLocation
  amp_p0 = 0.0

// Wave (1)
  pulShp_p1 = nPulseShape
  tdelay_p1 = 0.0
  pulLeng_p1 = pulseLength
  chirp_p1 = 0.0
  spotSize_p1 = waistSize
  waveLeng_p1 = laserWavelength
  focus_p1 = waistLocation
  amp_p1 = peakElectricField

  EFFlag = 0 
  name = PortGauss
}


ExitPort
{
  j1 = 0
  k1 = Ny 
  j2 = Nx 
  k2 = Ny 
  normal = -1
  EFFlag = 0 
  name = ExitPort
  C = 0
  A = 0
}

ExitPort
{
  j1 = 0
  k1 = 0 
  j2 = Nx 
  k2 = 0 
  normal = 1
  EFFlag = 0 
  name = ExitPort
  C = 0
  A = 0
}

Conductor
{
  j1 = Nx
  k1 = 0
  j2 = Nx
  k2 = Ny
  normal = -1
  EFFlag = 0 
  name = ExitPort
  C = 0
  A = 0
}

}