1. XS file

For the macro XS cases, user needs to write case related XS file. Comments are supported in the input file. All characters following an exclamation mark ! are commentary and are ignored by NECP-X. All strings in input card are case insensitive.

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The XS file is like:

    <ng>
    
    mixture <id_mat> <order>             !material
    <tr_1> <nf_1> <kf_1> <chi_1>         !group 1
    <tr_2> <nf_2> <kf_2> <chi_2>         !group 2
     .
     .
     .
    <tr_ng> <nf_ng> <kf_ng> <chi_ng>     !group ng
    <sc_1-1> <sc_2-1> ... <sc_ng-1>      !to group 1
    <sc_1-2> <sc_2-2> ... <sc_ng-2>      !to group 2
     .
     .
     .
    <sc_1-ng> <sc_2-ng> ... <sc_ng-ng>   !to group ng
    
    
    [ mixture <id_mat> <order>           !material
      <tr_1> <nf_1> <kf_1> <chi_1>       !group 1
      <tr_2> <nf_2> <kf_2> <chi_2>       !group 2
       .
       .
       .
      <tr_ng> <nf_ng> <kf_ng> <chi_ng>   !group ng
      <sc_1-1> <sc_2-1> ... <sc_ng-1>    !to group 1
      <sc_1-2> <sc_2-2> ... <sc_ng-2>    !to group 2
       .
       .
       .
      <sc_1-ng> <sc_2-ng> ... <sc_ng-ng> !to group ng
    ]

ng

·        integer value

·        group number of XS

mixture keyword

Specifies the information of the mixture for the macro problems.

id_mat

·        String value

·        id of material

order

·        Integer value

·        Order of scattering matrix,

·        Only support 0 for the macro problems

tr_1

·        Real value

·        transport corrected xs of group 1

nf_1

·        Real value

·        mu*fission of group 1

kf_1

·        Real value

·        kappa*fission of group 1

chi_1

·        Real value

·        fission sepctrum of group 1

sc_2-1

·        Real value

·        scattering xs from group 2 to group 1