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java.lang.Objectspis.Surf.InteractModel.FunctionOfParticle
spis.Surf.InteractModel.FunctionOfParticleETheta
spis.Surf.InteractModel.SEEPYieldFunction1
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)
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 number Author (name, e-mail) Corrections/Modifications
0.1 JF Roussel, roussel@onecert.fr Creation
Field Summary | |
private ParameterSet[] |
c1c2Params
c1 [eV-1] and c2 [m-1] params stored as parameter sets (cf. |
private float[] |
cF
array of c parameters (cf. |
private ParameterSet[] |
cParams
c params stored as parameter sets |
private ParameterSet[] |
EmaxParams
Emax parameters [eV] (extracted from params) |
private static ParamSetExtractor |
EmaxParamsExtractor
Emax parameters extractor |
private static int[] |
EmaxParamsPosition
position of the Emax parameter to be extracted from params parameters |
private ParameterSet[] |
params
input parameters from database (in SPIS units): SEEP yield [-] at 1 keV and energy [eV] at which SEEP is maximum |
private RangeFunction |
range
range function R(E) this SEE yield function is based upon (E in eV, R in meters) |
private static float |
refE
energy [eV] at which the yield is provided in params (normally 1000 eV) |
Fields inherited from class spis.Surf.InteractModel.FunctionOfParticle |
defaultParamsId, materialRange, modelId, particleId, partTable |
Constructor Summary | |
SEEPYieldFunction1(ParameterSet[] params,
ParameterSet[] c1c2Params,
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 float |
computeC(float Y1k,
float Emax,
float c1,
float c2)
Compute the c parameter in proton range function |
protected ParameterSet[] |
getC()
|
RangeFunction |
getProtonRange()
|
private void |
init()
performs initialisations, mostly c 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 |
private ParameterSet[] params
private ParameterSet[] c1c2Params
SEEPYieldFunction1
private ParameterSet[] EmaxParams
private ParameterSet[] cParams
private float[] cF
private RangeFunction range
private static float refE
private static int[] EmaxParamsPosition
private static ParamSetExtractor EmaxParamsExtractor
Constructor Detail |
public SEEPYieldFunction1(ParameterSet[] params, ParameterSet[] c1c2Params, int modelId, int particleId, PartTable partTable)
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] paramspartTable
- Method Detail |
private void init()
protected ParameterSet[] getC()
SEEPYieldFunction1
protected float compute(float E, float cosTheta, int matId)
compute
in class FunctionOfParticleETheta
E
- particle energy [eV]cosTheta
- cosine of indicence angle (1 <=> normal)matId
-
protected float compute(float E, int matId)
compute
in class FunctionOfParticleETheta
E
- particle energy [eV]matId
-
private float computeC(float Y1k, float Emax, float c1, float c2)
Y1k
- yield [-] for protons of energy 1000 eV (refE)Emax
- energy [eV] at which yield is maximumc1
- [eV-1]c2
- [m-1]
SEEPYieldFunction1
public RangeFunction getProtonRange()
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