spis.Surf.InteractModel
Class SEEEYieldFunction1

java.lang.Object
  extended byspis.Surf.InteractModel.FunctionOfParticle
      extended byspis.Surf.InteractModel.FunctionOfParticleETheta
          extended byspis.Surf.InteractModel.SEEEYieldFunction1
All Implemented Interfaces:
ScalFunctionOf2Scal, ScalFunctionOf4Scal, ScalFunctionOf5Scal, ScalFunctionOfScal

public class SEEEYieldFunction1
extends FunctionOfParticleETheta

Class Name : SEEEYieldFunction1
Project ref : SPIS project
File name : SEEEYieldFunction1.java
File type : class
Copyright : ONERA, 2 Av. E. Belin, 31055 Toulouse cedex, France http://www.onecert.fr
Status : under development
Creation : May 3, 2004
Modification :

Description : Simple yield for secondary electron emission from electron impact. This function is based on the asumption of a constant energy loss rate for a particle (simple version of NASCAP SEE model, cf (3.4) to (3.6) of NASCAP "a three dimensional dynamic study of electrostatic charging i nmaterials", Katz et al., NASA CR-135256).
It gives the SEE yield(E, theta) = c1 * § dE/dx * exp(-c2*x*cos(theta)) = c1 * (1-exp(-c2*cos(theta)*E*dR/dE)) / (c2*cos(theta)*dR/dE), with the c1 [eV-1] and c2 [m-1] parameters to be determined from SEE yield maximum.
In each ParameterSet (one set per material in ParameterSet[] parameter array), passed to the constructor, parameters must be:
- 0: NASCAP param 5: Maximum secondary electron emission (SEE) yield for electron impact [-].
- 1: modified NASCAP param 6: Primary electron energy that produces maximum SEE yield, in [eV] here, while it is in [keV] in NASCAP.

Versions and anomalies correction :

Version numberAuthor (name, e-mail) Corrections/Modifications
0.1 JF Roussel, roussel@onecert.frCreation


Version:
0.1
Author:
JF Roussel

Field Summary
private  float[][] c1c2F
          array of c1 [eV-1], c2 [m-1] parameters (cf.
private  ParameterSet[] c1c2Params
          c1-c2 params stored as parameter sets
private  ParameterSet[] params
          Double power law parameters
private  RangeFunction range
          range function R(E) this SEE yield function is based upon (E in eV, R in meters)
 
Fields inherited from class spis.Surf.InteractModel.FunctionOfParticle
defaultParamsId, materialRange, modelId, particleId, partTable
 
Constructor Summary
SEEEYieldFunction1(ParameterSet[] params_, RangeFunction range_, int modelId, int particleId, PartTable partTable)
           
 
Method Summary
protected  float compute(float E, float cosTheta, int matId)
          Returns the SEEE yield [-]
protected  float compute(float E, int matId)
          Returns the average SEEE yield for an isotropic distribution [-]
private  void computeC1C2(float Ym, float Em, RangeFunction range, float[] c1c2)
          Compute the c1 [eV-1] and c2 [m-1] parameters
protected  ParameterSet[] getC1C2params()
           
private  void init()
          performs initialisations, mostly c1 and c2 coefficients computation
 
Methods inherited from class spis.Surf.InteractModel.FunctionOfParticleETheta
compute, compute, compute, compute, compute, compute
 
Methods inherited from class spis.Surf.InteractModel.FunctionOfParticle
getDefaultParamsId, getMaterialRange, getModelId, getParticleId, getPartTable, selectParamSet, setDefaultParams, setDefaultParamsId, setMaterialRange, setModelId, setParticleId, setPartTable
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

params

private ParameterSet[] params
Double power law parameters


range

private RangeFunction range
range function R(E) this SEE yield function is based upon (E in eV, R in meters)


c1c2F

private float[][] c1c2F
array of c1 [eV-1], c2 [m-1] parameters (cf. NASCAP manual for their definition): c1c2F[i][0] is c1 for material i, c1c2F[i][1] is c2 for material i


c1c2Params

private ParameterSet[] c1c2Params
c1-c2 params stored as parameter sets

Constructor Detail

SEEEYieldFunction1

public SEEEYieldFunction1(ParameterSet[] params_,
                          RangeFunction range_,
                          int modelId,
                          int particleId,
                          PartTable partTable)
Parameters:
params_ -
partTable -
Method Detail

init

private void init()
performs initialisations, mostly c1 and c2 coefficients computation


getC1C2params

protected ParameterSet[] getC1C2params()
Returns:
the c1 [eV-1] and c2 [m-1] parameters (cf. NASCAP manual for their definition)
See Also:
SEEEYieldFunction1

compute

protected float compute(float E,
                        float cosTheta,
                        int matId)
Returns the SEEE yield [-]

Specified by:
compute in class FunctionOfParticleETheta
Parameters:
E - particle energy [eV]
cosTheta - cosine of indicence angle (1 <=> normal)
matId -
Returns:
yield [-]

compute

protected float compute(float E,
                        int matId)
Returns the average SEEE yield for an isotropic distribution [-]

Overrides:
compute in class FunctionOfParticleETheta
Parameters:
E - particle energy [eV]
matId -
Returns:
yield [-]

computeC1C2

private void computeC1C2(float Ym,
                         float Em,
                         RangeFunction range,
                         float[] c1c2)
Compute the c1 [eV-1] and c2 [m-1] parameters

Parameters:
Ym - yield at maximum [-]
Em - energy with maximum yield [eV]
range - range function (default non-material-indexed method compute(E) is used here)
c1c2 - results, c1 [eV-1] in c1c2[0] and c2 [m-1] in c1c2[1]