Changes for generating input to XGEN.

- Use xgen for the material number to get a xgen input file
- Examples using dry air
- New Windows executable
- Notes for this version of the code

DryAir_NoXGEN.inp

@@ -0,0 +1,13 @@
+Dry Air
+3
+Standard Density:  1.205e-3 g/cc @ 20 deg C, 1 atm
+See "Introduction to Radiological Physics 
+       and Radiation Dosimetry" by Attix p.531-532
+1.205e-3
+weight
+4
+nat 6   0.000124
+nat 7   0.755268
+nat 8   0.231781
+nat 18  0.012827
+100

DryAir_NoXGEN.out

@@ -0,0 +1,43 @@
+C
+C  Dry Air                                                          
+C
+C  Standard Density:  1.205e-3 g/cc @ 20 deg C, 1 atm                      
+C  See "Introduction to Radiological Physics                               
+C         and Radiation Dosimetry" by Attix p.531-532                      
+C
+C   Summary of MatMCNP (Version 4.1) Calculations:
+C
+C  Isotope  Number Fraction    Weight Fraction       Atoms/b-cm
+C   C-12        0.000149           0.000123          0.0000000
+C   C-13        0.000002           0.000001          0.0000000
+C   N-14        0.781575           0.752324          0.0000390
+C   N-15        0.002855           0.002944          0.0000001
+C   O-16        0.210236           0.231153          0.0000105
+C   O-17        0.000080           0.000094          0.0000000
+C   O-18        0.000432           0.000535          0.0000000
+C  Ar-36        0.000016           0.000039          0.0000000
+C  Ar-38        0.000003           0.000008          0.0000000
+C  Ar-40        0.004653           0.012781          0.0000002
+C
+C  The total compound atom density (atom/b-cm):  0.0000499
+C
+C
+C  This material contains an isotope that is often modified by 
+C  an S(alpha,beta). Check MCNP Manual Appendix G to see if an
+C  S(alpha,beta) card (i.e., an MTn card) is required.
+C
+M100    06012.00c   0.000149
+        06013.00c   0.000002
+        07014.00c   0.781575
+        07015.00c   0.002855
+        08016.00c   0.210236
+        08017.00c   0.000080
+        08018.00c   0.000432
+        18036.00c   0.000016
+        18038.00c   0.000003
+        18040.00c   0.004653
+C
+C  To convert a particle flux to rad[Material]
+C  use FM  6.6316863E-10 100  -4  1 for neutrons
+C   or FM  6.6316863E-10 100  -5 -6 for photons.
+C

DryAir_XGEN.inp

@@ -0,0 +1,13 @@
+Dry Air
+3
+Standard Density:  1.205e-3 g/cc @ 20 deg C, 1 atm
+See "Introduction to Radiological Physics 
+       and Radiation Dosimetry" by Attix p.531-532
+1.205e-3
+weight
+4
+nat 6   0.000124
+nat 7   0.755268
+nat 8   0.231781
+nat 18  0.012827
+xgen

DryAir_XGEN.out

@@ -0,0 +1,43 @@
+C
+C  Dry Air                                                          
+C
+C  Standard Density:  1.205e-3 g/cc @ 20 deg C, 1 atm                      
+C  See "Introduction to Radiological Physics                               
+C         and Radiation Dosimetry" by Attix p.531-532                      
+C
+C   Summary of MatMCNP (Version 4.1) Calculations:
+C
+C  Isotope  Number Fraction    Weight Fraction       Atoms/b-cm
+C   C-12        0.000149           0.000123          0.0000000
+C   C-13        0.000002           0.000001          0.0000000
+C   N-14        0.781575           0.752324          0.0000390
+C   N-15        0.002855           0.002944          0.0000001
+C   O-16        0.210236           0.231153          0.0000105
+C   O-17        0.000080           0.000094          0.0000000
+C   O-18        0.000432           0.000535          0.0000000
+C  Ar-36        0.000016           0.000039          0.0000000
+C  Ar-38        0.000003           0.000008          0.0000000
+C  Ar-40        0.004653           0.012781          0.0000002
+C
+C  The total compound atom density (atom/b-cm):  0.0000499
+C
+C
+C  This material contains an isotope that is often modified by 
+C  an S(alpha,beta). Check MCNP Manual Appendix G to see if an
+C  S(alpha,beta) card (i.e., an MTn card) is required.
+C
+Mxgen   06012.00c   0.000149
+        06013.00c   0.000002
+        07014.00c   0.781575
+        07015.00c   0.002855
+        08016.00c   0.210236
+        08017.00c   0.000080
+        08018.00c   0.000432
+        18036.00c   0.000016
+        18038.00c   0.000003
+        18040.00c   0.004653
+C
+C  To convert a particle flux to rad[Material]
+C  use FM  6.6316863E-10 xgen -4  1 for neutrons
+C   or FM  6.6316863E-10 xgen -5 -6 for photons.
+C

MatMCNP.bat

@@ -20,7 +20,7 @@ rem
 rem
 rem   Copy the executable file to working directory
 rem
-  COPY bin\MatMCNP.exe  MatMCNP.exe
+  COPY bin\MatMCNP_vXGEN.exe  MatMCNP.exe
 rem
 rem
 rem   Run the job

VersionXGEN_Notes.txt

@@ -0,0 +1,40 @@
+Notes on changes for MatMCNP Version XGEN
+ - February 2021
+-------------------------------
+
+This modification allows the user to create material files for use with the xgen program. XGEN
+is a utility code for producing continuous energy electron/photon cross sections for use with the
+Integrated Tiger Series (ITS) code system. This modification to MatMCNP does not change any of the 
+calculations previously discussed and verified. It is simply a new format to output the results.
+
+To invoke the XGEN input generation, simply replace the material number intended for the MCNP
+material number with "xgen". The xgen input uses a default energy of 1.0 MeV which must be changed if
+your ITS problem has a different maximum energy. The density output in the xgen input file will need
+verification if you are using less density (< 1.0e-5 g/cc) materials.
+
+With these changes, MatMCNP expects no arguments, 2 arguments, or 3 arguments.
+ (1) No arguments on the command line:
+     - Input file:  matmcnp.inp
+     - Output file: matmcnp.out
+     - XGEN input:  matxgen.inp
+
+ (2) Two arguments on the command line:
+     - Input file:  First argument
+     - Output file: Second argument
+     - XGEN input:  matxgen.inp
+
+ (3) Three arguments on the command line:
+     - Input file:  First argument
+     - Output file: Second argument
+     - XGEN input:  Third argument
+
+An example using Dry Air has been added.
+
+New Files:
+(1) VersionXGEN_Notes.txt - This file
+(2) DryAir_NoXGEN.inp - An input file using original MatMCNP input format
+(3) DryAir_NoXGEN.out - Output file from (2)
+(4) DryAir_XGEN.inp - A MatMCNP input file that will generate an xgen input
+(5) DryAir_XGEN.out - Output file from (4)
+(6) XGEN_DryAir.inp - A file that can be used by xgen to generate cross sections for ITS
+(7) bin/MatMCNP_vXGEN.exe - A Windows executable built with gfortran using the makefile in /source

XGEN_DryAir.inp

@@ -0,0 +1,35 @@
+TITLE
+... Dry Air                                                         
+energy 1.00
+*                                                                                
+*   Standard Density:  1.205e-3 g/cc @ 20 deg C, 1 atm                           
+*   See "Introduction to Radiological Physics                                    
+*          and Radiation Dosimetry" by Attix p.531-532                           
+*                                                                                
+*    Summary of MatMCNP (Version 4.1) Calculations:                              
+*                                                                                
+*   Isotope  Number Fraction    Weight Fraction       Atoms/b-cm                 
+*    C-12        0.000149           0.000123          0.0000000                  
+*    C-13        0.000002           0.000001          0.0000000                  
+*    N-14        0.781575           0.752324          0.0000390                  
+*    N-15        0.002855           0.002944          0.0000001                  
+*    O-16        0.210236           0.231153          0.0000105                  
+*    O-17        0.000080           0.000094          0.0000000                  
+*    O-18        0.000432           0.000535          0.0000000                  
+*   Ar-36        0.000016           0.000039          0.0000000                  
+*   Ar-38        0.000003           0.000008          0.0000000                  
+*   Ar-40        0.004653           0.012781          0.0000002                  
+*                                                                                
+*   The total compound atom density (atom/b-cm):  0.0000499                      
+*                                                                                
+*                                                                                
+*   This material contains an isotope that is often modified by                  
+*   an S(alpha,beta). Check MCNP Manual Appendix G to see if an                  
+*   S(alpha,beta) card (i.e., an MTn card) is required.                          
+*                                                                                
+MATERIAL
+  C    0.0001240
+  N    0.7552680
+  O    0.2317810
+  Ar   0.0128270
+DENSITY    0.0012050