1How to read and modify
XSDIR file
Japan Atomic Energy Agency (JAEA)
Kenichi TADA

2Contents• Overview of XSDIR file
• Data in XSDIR file
• Modification of XSDIR file when user add newACE file• Automated XSDIR generation tool3

What is XSDIR file?
• XSDIR: Information list of ACE files• XSDIR contains information, e.g., nuclide/material ID,
path of ACE file, and numbers of data, to handle ACE file.
• Nuclear calculation codes, e.g., MCNP and PHITS,

required nuclide ID and material ID for their inputfiles.

• For example, 1001.50c for H-001, 92235.10c for U-235,

and lwtr.10t for HinH2O.

Example of XSDIR

4Ratio of mass of material tothat of neutron (AWR)

atomic weight ratios
0001 1.000000
0001 1.000000
1000 0.99931697 1001 0.99916733 1002 1.99679968
2000 3.96821760 2003 2.99012018 2004 3.96821897
3000 6.88131188 3004 3.99259010 3005 4.96947769
3006 5.96345000 3007 6.95573370
19/10/2016
ACE file directory path informationdirectory
1001.80c 0.999167 j40/H001.ace 0 1 4 17969 0 0 2.5301E-8
2003.80c 2.989032 j40/He003.ace 0 1 4 10004 0 0 2.5301E-8
92235.80c 233.0248 j40/U235.ace 0 1 4 837481 0 0 2.5301E-8 ptable
92235.70c 233.0248 j40f01j 0 1 1238702 832644 0 0 2.5301E-08 ptable
92235.71c 233.0248 j40f01j 0 1 1446875 689688 0 0 5.1704E-08 ptable
lwtr.20t 0.999167
j40tsl/lwtr.20t 0 1 1 1228849 0 0 2.530E-08
lwtr.21t 0.999167
j40tsl/lwtr.21t 0 1 1 1201502 0 0 3.016E-08
lwtr.22t 0.999167j40tsl/lwtr.22t 0 1 1 1165553 0 0 3.447E-08

nuclide/material ID, .suffix number, ACE data class, AWR, File name and path, 0, 1,Data position (Start data position/Total data number), 0, 0, Temperature [MeV], Useprobability table
Ref.：“MCNP USER’S MANUAL Code Version 6.2,” LA-UR-17-29981

5Features of XSDIR• XSDIR contains several temperature data and several

library data with one file.

• Transport codes distinguish these different data by suffixnumber.

• Available suffix number: .00～.99• The last character of nuclide/material name means ACE dataclass.

HinH2O U-235• c：continuous-energy neutron data, t：thermal scattering law data
92235.80c 233.0248 j40/U235.ace 0 1 1 837481 0 0 2.5301E-8 ptable
92235.70c 233.0248 j40f01j 0 1 1238702 832644 0 0 2.5301E-08 ptable
92235.71c 233.0248 j40f01j 0 1 1446875 689688 0 0 5.1704E-08 ptable
lwtr.20t 0.999167
j40tsl/lwtr.20t 0 1 1 1228849 0 0 2.530E-08
lwtr.21t 0.999167
j40tsl/lwtr.21t 0 1 1 1201502 0 0 3.016E-08
lwtr.22t 0.999167
j40tsl/lwtr.22t 0 1 1 1165553 0 0 3.447E-08

6ACE data class list
ZAID suffix
ctypu
hor
sa

ACE Data Class
continuous-energy neutron data
thermal S(α, β)data
dosimetry data
photo-atomic data
Photonuclear data
continuous-energy proton data
continuous-energy deuteron data
continuous-energy triton data
continuous-energy 3He data
continuous-energy alpha data

Ref.: “The NJOY Nuclear Data Processing System, Version 2016,” LA-UR-17-20093.

7Notes on Nuclide/Material name (1/2)• Suffix number must be different if user adds other

ACE file to a XSDIR file.

• Suffix number depends on ACE file generator.
• Transport code user has to read the ACE file manual andcheck the suffix number.

Transport code reads first 92235.80c data if identical suffix number is found.
92235.80c 233.0248 j40/U235.ace 0 1 1 837481 0 0 2.5301E-8 ptable
92235.80c 233.0248 j40f01j 0 1 1238702 832644 0 0 2.5301E-08 ptable
92235.80c 233.0248 j40f01j 0 1 1446875 689688 0 0 5.1704E-08 ptable
Transport code cannot readthese ACE files

8Notes on Nuclide/Material name (2/2)• Transport codes do not need suffix number in their

input file.

• With suffix number: 92235.80c, lwtr.20t, …
• Transport code checks suffix number in XSDIR file and reads
corresponding nuclide/material data.
• Without suffix number: 92235, lwtr, …
• Transport code does not check suffix number and read firstnuclide/material data.
• User has to check whether this nuclide/material data is chosentemperature and evaluated data library or not.
Transport code reads 92235.80c if user sets 92235 (without suffix number).
92235.80c 233.0248 j40/U235.ace 0 1 1 837481 0 0 2.5301E-8 ptable
92235.70c 233.0248 j40f01j 0 1 1238702 832644 0 0 2.5301E-08 ptable
92235.71c 233.0248 j40f01j 0 1 1446875 689688 0 0 5.1704E-08 ptable9

How to modify nuclide/material name?

• Transport code users sometimes wants to modify

material name and suffix number.

• Suffix number is overlapped.
• Material name of transport code is different to that of ACE file.

• User only modifies XSDIR file and first line of ACE file
• Number of characters in each data must not be changed.
• User has to add blank character if number of characters is changed.
• “HinH2O.20t” -> “lwtr.20t ” (Add two blank characters)

92235.71c 233.0248 j40f01j 0 1 1446875 689688 0 0 5.1704E-08 ptable
lwtr.20t 0.999167 j40tsl/lwtr.20t 0 1 1 1228849 0 0 2.530E-08
92235.71c 233.024800 5.1704e-08 20171005
U235 from JENDL-4mat9228
00000000lwtr.20t 0.999167 2.5300e-08 20161017
01_h_in_h2o from JENDL-4
10010000000mat 125

XSDIRfile
1st-3rd linesof ACE files

10Data in XSDIR file

• XSDIR has two data region, i.e., “atomic weightratios” and “directory”.
• Atomic weight ratios (AWR)• List of ratio of mass of material to that of neutron• LANL provides atomic weight ratios list
• https://nucleardata.lanl.gov/ACE/install.html#AWR• Released XSDIR files are also useful to make AWR list.

• Directory• ACE file directory path information• Nuclide/material name, file path, …
nuclide/material ID, .suffix number, ACE data class, AWR, File name and path, 0, 1,Data position (Start data position/Total data number), 0, 0, Temperature [MeV], Useprobability table11ACE file directory path information• ACE file directory path information consists of 11 data.
• (1) Nuclide/material name (Maximum: 10 characters)• (2) Atomic weight ratio (AWR)• (3) File name (Maximum: 60 characters)• (4) Directory path (Maximum: 70 characters)• (5) ACE file mode (1: ASCII, 2: binary)• (6) Start line number of ACE file• (7) Total data number of ACE file
• (8), (9) Used for binary mode
• (10) Temperature [MeV]• (11) Whether probability table is contained or not.
92235.70c 233.0248 j40f01j 0 1 1238702 832644 0 0 2.5301E-08 ptable• (1), (2), and (5)-(11) are output in a XSDIR file which isgenerated with ACE file generation.

• Data that need to be modified: (1), (3), and (4).

12Notes on XSDIR modification• Maximum number of characters per line: 80• Please add “+” at the end of line and write next line if
number of characters is larger than 80.
• Number of characters per line including “+” mustbe less than 80.
92235.80c 233.0248 j40/rev1/U235.ace 0 1 1 837481 0 0 2.5301E-8 +ptable• Relative path from XSDIR file is directory path/filename”• “File name” is only available when directory pathis “0”• “j40/rev1/U235.ace” is relative path from XSDIR file.

13Addition of ACE file information• Nuclear data processing code automatically generates

XSDIR file when user generates ACE file.

• “ace_dif_file_name” for FRENDY (default is “~.ace.dir”)• “tapeXX” for NJOY (set in ndir in ACER card 1)• User has to add the data of generated XSDIR to combined

XSDIR file.

• Combined XSDIR file: Used for transport calculations• Suffix number must not be overlapped.
• Material name, e.g., lwtr, must be identical to input file of transport

code.
• Modify filename and route• Number of characters per line must be less than 80.

• Add “+” at the end of line and write next line if number of characters is larger

than 80.

[Examples of automatically generated XSDIR file using FRENDY and NJOY]

92235.80c 233.048 filename route 1 1 837481 0 0 2.585E-8 ptable
lwtr.20t
0.999167 filename route 1 1 2431237 0 0 2.585E-8

14

Example of addition of ACE file information[Examples of automatically generated XSDIR file using FRENDY and NJOY]
92235.80c 233.048 filename route 1 1 837481 0 0 2.585E-8 ptable
lwtr.20t0.999167 filename route 1 1 2431237 0 0 2.585E-8[Example of addition of ACE file information]
1) Modify
suffix numberof92235.80c 233.0248
j40/U235.ace
0 1 1 837481
0 0 2.5301E-8 ptable
92235.70c 233.0248XSDIR
j40f01j and0 1 1238702
ACE files832644 0 0 2.5301E-08 ptable
92235.71c 233.0248 j40f01j 0 1 1446875 689688 0 0 5.1704E-08 ptable
92235.60c 233.048 mod/u235.ace 0 1 1 837481 0 0 2.585E-8 +ptable2) Modify ACE file namelwtr.20t 0.999167 j40tsl/lwtr.20t
0 1 1 1228849 0 0 2.530E-08
lwtr.21t 0.999167 j40tsl/lwtr.21t
0 1 1 1201502 0 0 3.016E-08
lwtr.22t 0.999167 j40tsl/lwtr.22t
0 1 1 1165553 0 0 3.447E-08
lwtr.60t 0.999167 mod/hinh2o.ace 0 1 1 2431237 0 0 2.585E-84) Add “+” at the end of line
and write next line if number ofcharacters is larger than 80.

3) Modify directory pathfrom “route”to “0”Automated XSDIR generation tool15• FRENDY prepares the tool to generate XSDIR file.
• This tool automatically collect ACE files and modify XSDIR file.
• tools/make_xsdir_list[Example of generated XSDIR file]1001.50c
2004.50c
3007.50c

Modified by tool

0.999167 ｊ40/j40f00fa 0 1
19751 0 0 2.551e-08
3.968200 j40/j40f00fa 0 1 76161 25308 0 0 2.551e-08
6.955730 j40/j40f00fa 0 1 89852 29277 0 0 2.551e-08• Input of collection tools (See tools/README_tools)• Type of ACE data file• 1: neutron, 2: Thermal scattering law (TSL) data, 3: dosimetry data

• Modified ACE file name
• New XSDIR file name
• ACE file directory name that user

wants to collet ACE files.
• Suffix number• Processing mode (option)[Example of neutron[Example of TSL data]induced data]

1./j40f00f./j40f00f.xsdir./ace/j4050c
individual2./j40f00t./j40f00t.xsdir./ace/j40/sab20t
individual

16

Improvement of XSDIR generation tool (1/2)• XSDIR generation tool is improved in FRENDY Ver.2.
• The old version combined multiple ACE files in to one.
• The new version can generate XSDIR file without
combination of ACE files.

ACE file name isidentical to nuclear ID

17

Improvement of XSDIR generation tool (2/2)• Automatically generation of atomic weight ratios(AWR) data at the top of the XSDIR file.

• AWR values of natural materials e.g., 1000 and 2000, areobtained from XSDIR of ENDF/B-VIII.0.

• Number of significant digits of this tool is smaller than that of ENDF/B-VIII.0. (12 -> 9)

Date is also
automatically output.

AWR in ACE file