spis.Surf.InteractModel
Class SEEPYieldFunction1

java.lang.Object
  extended byspis.Surf.InteractModel.FunctionOfParticle
      extended byspis.Surf.InteractModel.FunctionOfParticleETheta
          extended byspis.Surf.InteractModel.SEEPYieldFunction1
All Implemented Interfaces:
ScalFunctionOf2Scal, ScalFunctionOf4Scal, ScalFunctionOf5Scal, ScalFunctionOfScal

public class SEEPYieldFunction1
extends FunctionOfParticleETheta

Class Name : SEEPYieldFunction1
Project ref : SPIS project
File name : SEEPYieldFunction1.java
File type : class
Copyright : ONERA, 2 Av. E. Belin, 31055 Toulouse cedex, France http://www.onecert.fr
Status : under development
Creation : 21 oct. 2004
Modification :

Description : Simple yield for secondary electron emission from proton 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 c1 and c2 passed to the constructor (they are to be determined previously from SEE from electrons, cf SEEEYieldFunction1).
The range function for protons is defined by:
R(E) = 1/c (2E^(1/2) + 2/3 E^(3/2)/Emax)
(derived from NASCAP manual Eq 3.14: -dE/dx = cE^1/2 / (1+E/Emax)

Version:
0.1
Author:
JF Roussel
See Also:
spis.Surf.InteractModel.ProtonRangeFunction1)
where Emax is a NASCAP parameter and c is determined so as to give the right SEEP yield at 1 kev.
This class handles 3 different ParameterSet arrays (there is one set per material in each of the 3 ParameterSet[] parameter arrays).
ParameterSet[] params passed to the constructor are NASCAP parameters in SPIS units:
- 0: NASCAP param 11: Secondary electron yield due to impact of 1 keV protons [-]
- 1: NASCAP param 12: Incident proton energy that produces maximum secondary electron yield [eV].
ParameterSet[] c1c2Params are passed to the constructor and have to be computed somewhere else (normally in SEEEYieldFunction1):
- 0: c1 [eV-1] in yield function above (energy conversion efficiency)
- 1: c2 [m-1] in yield function above ("transfer to surface" parameter).
ParameterSet[] cParams are computed here and contain only:
- c parameter [m-1.eV1/2] in proton range function above.
It may be requested from this class (to compute proton range function).

Summary of units policy for this Function:
everything is SPIS units (eV, m...).

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



Constructor Summary
SEEPYieldFunction1(ParameterSet[] params, ParameterSet[] c1c2Params, int modelId, int particleId, PartTable partTable)
           
 
Method Summary
 RangeFunction getProtonRange()
           
 
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, setDefaultParams, setDefaultParamsId, setMaterialRange, setModelId, setParticleId, setPartTable
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SEEPYieldFunction1

public SEEPYieldFunction1(ParameterSet[] params,
                          ParameterSet[] c1c2Params,
                          int modelId,
                          int particleId,
                          PartTable partTable)
Parameters:
params - NASCAP params 11 and 12: Secondary electron yield due to impact of 1 keV protons [-] and incident proton energy that produces maximum secondary electron yield in SPIS units [eV]
c1c2Params - c1 [eV-1] and c2 [m-1] params
partTable -
Method Detail

getProtonRange

public RangeFunction getProtonRange()
Returns:
Returns the range.