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&MODEL

 

This record is used to describe the simulation model and related quantities.

AHISV --- Maximum Depth Simulating Auger Electrons

This variable specifies the maximum depth for Auger electron generation. Auger electrons which are generated in a depth greater than specified in AHISV from sample surface are neglected. See Chapter A.5 for more detailed information.

AUGMUL --- Auger Electron Multiplication Factor

This variable actually describes the amount of CPU time which is to be spent simulating Auger electrons. For more information refer to Chapter A.5.

FMAT --- Filenames of Dielectric Data

This variable is a string specifying the datafiles of each region which contain the dielectric data to be used when simulating plasmon losses. Dielectric data is required to use the direct simulation model and in simulating Auger electrons. Appropriate file names are: "mat".diel Possible materials ("mat") can be found in Table A.1.

ION --- Ionization of Shells

This variable specifies the shells of the atoms to be explicitly taken into account for the calculation of ionizations. In that way it is possible to explicitly take ionizations into account during the simulation although their generation is not needed for any output specified in the input deck (see Chapter 9.9). Additionally, all shells specified in the &OUTPUT namelist for output to the screen or to a file and all shells which have to be taken into account according to the specification of characteristic x-ray lines in XCHAR are automatically taken into account. This means that shells specified for output in &OUTPUT do not need to be specified here. ION(I) is a string specifying the element (chemical abbreviation) EL and then the shell(s) SH, all separated by commas: ION(I)='EL,SH,SH,...'. I is only a running index. Possible shells are: K, L1, L2, L3, M1, M2, M3, M4, M5. Additionally, all shells may be chosen at once by specifying 'ALL' or '*', all L-shells by specifying 'L', and all M-shells by specifying 'M'. All elements of the target (according to ATOM in &TARGET) may be chosen by simply specifying 'ALL' or '*' instead of the chemical abbreviation. For a compact overview of possible methods of specifying ionizations see Table 9.4.

IONCRS --- Ionization Cross Section

This variable specifies the ionization cross section which should be taken for the calculation of ionizations (and characteristic x-rays) when the single scattering model, SIN (see MODR), is applied. Two different ionization cross sections may be chosen, one from Gryzinski ( GRY) and the other one from Pouchou ( POU) (see Chapter A.2). If in at least one region the hybrid model ( HYB) is specified then the Gryzinski ionization cross section ( GRY) is automatically applied in all regions where the single scattering model ( SIN) is taken. This guarantees consistent results since the Gryzinski ionization cross section is applied for taking into account inelastic scattering in the hybrid model ( HYB). For more information on the implemented models see Chapter A.

LSECON --- Simulation of Secondary Electrons

This variable specifies whether secondary electrons shall be simulated. If set to try then secondary electrons are simulated. The default value is F.

MODR --- Model in Region

This variable specifies which model be to applied to the different regions. If no model is explicitly specified then the model according to the TECHQU and/or SIGNAL key in the &INIT record is taken (see Tables 9.2 and 9.1). If a model is only explicitly specified for the first region then the same model will be also applied to all other regions. Three different models are implemented in version 1.1, a single scattering model ( SIN), a hybrid model ( HYB) and a direct simulation model ( DIR). For more information concerning these three models see Appendix A. The default model is SIN for the Signals XC and IO, HYB for BE and TE, and DIR for SE and AE. For more information on SIGNAL see Chapter 9.1, the description of the &INIT namelist.

STOPP --- Stopping Power

This variable specifies the stopping power which should be taken to calculate the energy loss of electrons if either the single scattering model, SIN (see MODR), or the hybrid model, HYB (see MODR), is applied. Two different stopping power formulas may be chosen, one from Luo and Joy ( LUO) and the other one from Bethe ( BET) In both cases the stopping power for energies higher than 60 keV are calculated using the relativistic Bethe stopping poser formula. For more information on the implemeted sopptin power euations see Chapter A.2. For low energies the Luo and Joy expression seems to give somehow better results. Therefore this formula is taken as the default stopping power.

XCHAR --- Characteristic X-ray Line(s)

This variable specifies the characteristic x-ray lines to be taken into account during the simulation additionally to the lines specified by one of the possible variables of the &OUTPUT namelist (see Chapter 9.9). XCHAR(I) is a string specifying the element (chemical abbreviation) EL and then the characteristic x-ray line(s) CL, all separated by commas: XCHAR(I)='EL,CL,CL,...'. I is only a running index. Possible lines are: Ka1, Ka2, Kb, La1, La2, Lb1, Lb2, Lb3, Ma, and Mb. Additionally, all lines may be chosen at once by specifying 'ALL' or '*', all K-alpha lines by specifying Ka, all L-lines by specifying 'L', all L-alpha lines by specifying La, all L-beta lines by specifying Lb, and all M-lines by specifying 'M'. All elements of the target (according to ATOM in &TARGET) may be chosen by simply specifying 'ALL' or '*' instead of the chemical abbreviation. For more information on such specifications and their default values see Table 9.5



next up previous contents
Next: &MSETUP Up: Input Records Previous: &TARGET



Horst Wagner
Tue Mar 19 10:24:55 MET 1996