EXFOR Basics
II. Overview of the EXFOR Exchange Format

(table of contents)

General Structure of the Exchange Format

Nuclear reaction data is exchanged within the EXFOR System on EXFOR exchange files (transmissions), sometimes also called TRANS files.

This section describes the general structure and the general format of an EXFOR exchange file. More specific information may be found in the following sections.

An exchange file contains a number of entries (works). Each entry is divided into a number of subentries (data sets). Each entry is assigned an accession number; each subentry is assigned a subaccession number (the accession number plus a subentry number). The subaccession numbers are associated with a data table throughout the life of the EXFOR system.

The subentries are further divided into:

The file may, therefore, be considered to be of the following form:

EntrySubentrySection
FileEntry #1Subentry #1Bibliographic Information
Common Data
Subentry #2Bibliographic Information
Common Data
Data Table
Subentry #3Bibliographic Information
Common Data
Data Table
...........
Entry #2Subentry #1Bibliographic Information
Common Data
Subentry #2Bibliographic Information
Common Data
Data Table
Subentry #3Bibliographic Information
Common Data
Data Table
...........
...........

In order to avoid repetition of information that is common to all subentries within an entry or to all lines within a subentry, information may be associated with an entire entry or with an entire subentry. To accomplish this, the first subentry of each work contains only information that applies to all other subentries. Within each subentry, the information common to all lines of the table precedes the table.

Two levels of hierarchy are thereby established:

EntrySubentries
Common Subentry→Bibliographic Information
Common Data
Data Subentry →Bibliographic Information
Common Data
Data Table

Permitted character set

The following characters are permitted for use in the exchange format:

All Roman characters, A to Z and a to z

All numbers, 0 to 9

The special characters:

+(plus) ;(semi-colon)
-(minus) !(exclamation mark)
.(decimal point/full stop)?(question mark)
)(right parenthesis) &(ampersand)
((left parenthesis) #(number symbol)
*(asterisk) [(opening bracket)
/(slash) ](closing bracket)
=(equals) "(quotation mark)
'(apostrophe) ~(varies as sign)
,(comma) @(at symbol)
%(percent) {(left curly brace)
<(less than) }(right curly brace)
>(greater than) |(vertical bar)
:(colon)

Identification of Files, Entries, and Subentries

In order to track, access, and identify data within the EXFOR Exchange System, the following labelling systems have been adopted for files, entries and subentries.

Each of these labels includes a center-identification character as the first character in the string. The table below lists the center-identification characters that have been assigned. These characters define both the center at which the information was compiled and the type of data compiled. (Neutron, charged-particle, and photonuclear reaction data are compiled in separate entries with appropriate identification, even if they were reported in the same reference.)

Center Identification Characters
1NNDC (Brookhaven) Neutron nuclear data
2NEA-DB (Paris) Neutron nuclear data
3NDS (Vienna) Neutron nuclear data, including also compilations from CNDC, UkrNDC and India
4CJD (Obninsk) Neutron nuclear data
ACAJaD (Moscow) Charged-particle nuclear data, including also earlier compilations from CNPD
BKaChaPaG (Karlsruhe)Charged-particle nuclear data (extinct centre)
CNNDC (Brookhaven) Charged-particle nuclear data
DNDS (Vienna) Charged-particle nuclear data, including also compilations from ATOMKI, UkrNDC and India
EJCPRG (Sapporo) Charged-particle nuclear data
FCNPD (Sarov) Charged-particle nuclear data
GNDS (Vienna) Photonuclear data, including also compilations from UkrNDC
JJCPRG (Sapporo) Charged-particle nuclear data for projectiles with nonpositive baryon number
KJCPRG (Sapporo) Photonuclear data
LNNDC (Brookhaven) Photonuclear data
MCDFE (Moscow) Photonuclear data
ONEA-DB (Paris) Charged-particle nuclear data
PNNDC (Brookhaven) Charged-particle nuclear data from MacGowen file
RRIKEN (Wako, Japan) Charged-particle nuclear data (extinct centre)
SCNDC (Beijing) Charged-particle nuclear data
TCNPD/NNDC Charged-particle nuclear data
VNDS (Vienna) Special use for selected evaluated neutron data 'VIEN' file (extinct series)

EXFOR Records

EXFOR Exchange files consist of 80 character ASCII records. The format of columns 1-66 varies according to the record type as outlined in the following sections. Columns 67-79 is used to uniquely identify a record within the file. The records on the file are in ascending order according to the record identification. Column 80 is presently not used.

Record identification.The record identification is divided into three fields: the accession number (entry), subaccession number (subentry), and record number within the subentry. The format of these fields is as follows.

Column67-71Center-assigned accession number
72-74Subaccession number
75-79Sequence number

System Identifiers

Each of the following basic system identifiers refers to one of the hierarchy of units contained on an exchange file. Each of the following system identifiers indicates the beginning of one of these sections.

TRANS - A file is the unit
(only on files for exchange between data centres. In user retrieval files this identifier may be missing or be replaced by another keyword such as 'REQUEST')
ENTRY - An entry (work) is the unit
SUBENT- A subentry (data set) is the unit
BIB - The Bibliographic Information section (hereafter referred to as the BIB section) of a complete work or sub-work is the unit
COMMON- The Common Data section of a complete work or sub-work is the unit
DATA - The Data Table section of a sub-work is the unit

These basic system identifiers may be combined with the modifiers

NO
END

to indicate three conditions:

The following system identifiers are defined.

1. A file is: Headed by: 

TRANS      cxxx       yyyymmdd

Ended by: 

ENDTRANS              N1

N1 = number of entries (accession numbers) on the file.

2. An entry is:

Headed by: 

ENTRY      N1         N2

Ended by: 

ENDENTRY   N1

3. A subentry is:

Headed by: 

SUBENT     N1         N2

Ended by: 

ENDSUBENT  N1

If a subentry has been deleted, the following record may be included in the file(should appear only on centre-to-centre transmission files): 

NOSUBENT   N1         N2

4. A BIB section is:

Headed by 

BIB        N1         N2

Ended by : 

ENDBIB     N1

If no BIB section is given the following record is included: 

NOBIB

5. A COMMON section is:

Headed by: 

COMMON     N1         N2

Ended by: 

ENDCOMMON  N1

If no COMMON section is given, the following record is included: 

NOCOMMON

6. A DATA section is:

Headed by: 

DATA       N1         N2

Ended by: 

ENDDATA    N1

If no DATA section is given, the following record is included: 

NODATA

BIB, COMMON and DATA Sections

BIB Section

The BIB section contains the bibliographic information (e.g., reference, authors), descriptive information (e.g., neutron source, method, facility), and administrative information (e.g., history) associated with the data presented. It is identified on an exchange file as that information between the system identifiers BIB and ENDBIB.

A BIB record consists of three parts:

columns 1-11:
information-identifier keyword field,
columns 12-66:
information field, which may contain coded information and/or free text,
columns 67-79:
record identification field.

BIB information for a given data set consists of the information contained in the BIB section of its subentry together with the BIB information in subentry 001. That is, information coded in subentry 001 applies to all other subentries in the same entry. A specific information-identifier keyword may be included in either subentry or both.

Information-identifier keywords

The information-identifier keyword is used to define the significance of the information given in columns 12-66. The keyword is left adjusted to begin in column 1, and does not exceed a length of 10 characters (column 11 is either blank, or contains a pointer, see page 29).

These keywords may, in general, appear in any order within the BIB section, however, an information-identifier keyword is not repeated within any one BIB section. If pointers (see page 29) are present, they appear on the first record of the information to which they are attached and are not repeated on continuation records.

Coded (machine-retrievable) information

Coded information may be used:

Coded information is enclosed in parentheses and left adjusted so that the opening parenthesis appears in column 12. Several pieces of coded information may be associated with a given information-identifier keyword.

Codes for use with a specific keyword are found in the relevant dictionary. However, for some keywords, the code string may include retrievable information other than a code from one of the dictionaries.

In general, codes given in the dictionaries may be used singly or in conjunction with one or more codes from the same dictionary. Two options exist if more than one code is used:

a) two or more codes within the same set of parenthesis, separated by a comma;
Example: 
(SOLST,NAICR)
b) each code on a separate record, enclosed in it's own set of parenthesis starting in column 12, followed by free text.
Example: 
(SOLST)  free text
(NAICR)  free text

For some cases, the information may be continued onto successive records. Information on continuation records does not begin before column 12 (columns 1-10 are blank and column 11 is blank or contains a pointer).

Note that some information-identifier keywords have no coded information associated with them and that, for many keywords that may have coded information associated with them, it need not always be present.

Free text

Free text may be entered in columns 12-66 under each of the information-identifier keywords in the BIB section. The text follows any coded information on the record or may begin on a separate record; it may be continued onto any number of records.

The language of the free text is English.

COMMON and DATA Sections

A data table is, generally, a function of one or more independent variables, e.g.,

When more than one representation of Y is present, the table may be X vs. Y and Y', with associated errors for X, Y and Y' (e.g., X = energy, Y = absolute cross section, Y' = relative cross section), and possible associated information. The criteria for grouping Y with Y' are that they both be derived from the same experimental information by the author of the data.

For some data, the data table does not have an independent variable X but only a function Y. (Examples: Spontaneousν; resonance energies without resonance parameters)

Additional variables may be associated with the data, e.g., errors, standards.

The format of the common data (COMMON) and data table (DATA) sections is identical. Each section is a table of data containing the data headings and units associated with each field. The difference between the common data and data table is:

Each physical record may contain up to six information fields, each 11 columns wide. If more than six fields are used, the remaining information is contained on the following records. Therefore, a data line consists of up to three physical records. The number of fields in a data line is restricted to 18.

Records are not packed; rather, individual point information is kept on individual records; i.e., if only four fields are associated with a data line, the remaining two fields are left blank, and, in the case of the data table, the information for the next line begins on the following record. These rules also apply to the headings and units associated with each field.

The content of the COMMON and DATA sections are as follows:

The values are either zero or have absolute values between 1.0000E-38 and 9.999E+38.

COMMON Section

The COMMON section is identified as that information between the system identifiers COMMON and ENDCOMMON. In the common data table, only one value is entered for a given field, and successive fields are not integrally associated with one another.

An example of a common data table with more than 6 fields: 

1          12         23         34         45         56        66
COMMON
EN         EN-ERR     EN-RSL     E-LVL      E-LVL      MONIT
MONIT-ERR
MEV        MEV        MEV        MEV        MEV        MB
MB
2.73       0.02       0.05       2.73       2.78       3.456
0.123
ENDCOMMON

DATA Section

The DATA section is identified as that information between the system identifiers DATA and ENDDATA. In the DATA table, all entries on a record are integrally associated with an individual point. Independent variables precede dependent variables, and are monotonic until the value of the preceding independent variable, if any exist, changes.

Every line in a data table gives data information. This means, for example, that a blank in a field headed DATA is permitted only when another field contains the data information on the same line, e.g., under DATA-MAX. In the same way, each independent variable occurs at least once in each line (e.g., either under data headings E-LVL or E-LVL-MIN, E-LVL-MAX, see example below). Supplementary information, such as resolution or standard values, is not given on a line of a data table unless the line includes data information. Blanks are permitted in all fields.

An example of a point data table is shown below with its associated DATA and ENDDATA records. 

1          12         23         34         45         56        66
DATA
ANG        ANG-ERR    DATA       DATA-ERR   DATA-MAX
ADEG       ADEG       MB/SR      MB/SR      MB/SR
10.7       1.8        138.       8.5
22.9       1.2        127.       4.2
39.1       0.9                              83.2      
46.7       0.7        14.8       2.9
ENDDATA

Pointers

Different pieces of EXFOR information may be linked together by pointers. A pointer is a numeric or alphabetic character (1,2...9,A,B,...Z) placed in the eleventh column of the information-identifier keyword field in the BIB section and in the field headings in the COMMON or DATA section.

Pointers may link, for example,

In general, a pointer is valid for only one subentry. A pointer used in the first subentry applies to all subentries and has a unique meaning throughout the entire entry.

Pointers applied to a BIB keyword appear on the first record of the information to which they are attached and are not repeated on continuation records. A pointer is assumed to refer to all BIB information until either another pointer or a new keyword is encountered. As this implies, pointer-independent information for each keyword appears first.

Nuclide and reaction specification

Coding of nuclides and compounds

Nuclides appear in the coding of many keywords. The general code format is Z-S-A-X, where:

Z is the charge number; up to 3 digits, no leading zeros
S is the element symbol; 1 or 2 characters
A is the mass number; up to 3 digits, no leading zeroes. A single zero denotes natural isotopic composition.
X is an isomer code denoting the isomeric state; this subfield is not used if there are no known isomeric states.
X may have the following values:
G for ground state (of a nucleus which has a metastable state; may sometimes be omitted)
M if only one metastable state is regarded
M1 for the first metastable state
M2for the second, etc.
M2for the second, etc.
Lif only one quasi-metastable state [1] is regarded
L1for the first quasi-metastable state, etc.
Tfor sum of all isomers (limited to use within an isomeric ratio in SF4 of the reaction string)

Examples: 

92-U-235
49-IN-115-M/T

Compounds may in some cases replace the nuclide code. The general format for coding compounds is either the specific compound code, taken from a special compounds dictionary, or the general code for a compound of the form Z-S-CMP. The element coded is the major component of the compound.

Examples:

26-FE-CMPIron compound (details given in free text)
1-H-WTRWater

Reaction Specification

The reaction and quantity for the data coded in the data table is specified using the information-identifier keyword REACTION, therefore, this keyword must always be present in a data set. The keyword REACTION defines the data given in the DATA section under the heading DATA or a similar heading such as DATA-MIN, DATA-MAX, etc. The general format of the code is (reaction, quantity, data-type).

Reaction field.The reaction field consists of 4 subfields.

SF1. Target nucleus.Contains either:

a) a nuclide code.
A = 0 denotes natural isotopic mixture
-G for ground state is not used in this field
b) a compound code
c) a variable nucleus code ELEM and/or MASS
Example: (ELEM/MASS(0,B-),,PN)

SF2. Incident projectile. Contains one of the following:

a) a particle code from Dictionary 33
b) for particles heavier than an α, a nuclide code.

SF3. Process. Contains one of the following:

a) a process code from Dictionary 30, e.g., TOT.
b) a particle code from Dictionary 33 which may be preceded by a multiplicity factor, whose value may be 2→99, e.g., 4A.
c) for particles heavier than α, a nuclide code.
Examples:8-O-16, 8-O-16+8-O-16
d) combinations of a), b) and c), with the codes connected by '+'.
Examples:HE3+8-0-16, X+N

If SF5 contains the branch code (DEF) (it is not evident from the publication whether the reaction channel is undefined or defined), the particle codes given in SF3 may represent only the sum of emitted nucleons, implying that the product nucleus coded in SF4 has been formed via different reaction channels.

SF4. Reaction Product. In general, the heaviest of the products is defined as the reaction product (also called residual nucleus). In the case of two reaction products with equal mass, the one with the larger Z is considered as the heavier product. Exceptions or special cases are:

This subfield contains:

Quantity consists of four subfields, each separated by a comma. All combinations of codes allowed in the quantity field are given in Dictionary 236.

SF5 Branch.Indicates a partial reaction, e.g., to one of several energy levels.

SF6 Parameter.Indicates the reaction parameter given, e.g., differential cross section.

SF7 Particle Considered.Indicates to which of several outgoing particles the quantity refers. [2] When more than one particle or nuclide is entered, they are separated by a slash; if they are correlated particles, they are separated by a plus sign.

SF8 Modifier.Contains information on the representation of the data, e.g., relative data.

Data Type Field.Indicates whether the data are experimental, theoretical, evaluated, etc. Codes are found in Dictionary 35. The default value is 'experimental', therefore this field is very often omitted.

Variable Nucleus.For certain processes, the data table may contain yield or production cross sections for several nuclei which are entered as variables in the data table. In this case, either SF1 or SF4 of the REACTION keyword contain one of the following codes:

ELEM- if the Z (charge number) of the nuclide is given in the data table.
MASS- if the A (mass number) of the nuclide is given in the data table.
ELEM/MASS- if the Z and A of the nuclide are given in the data table.

The nuclei are entered in the common data or data table as variables under the data headings ELEMENT and/or MASS with the units NO-DIM.

If the data headings ELEMENT and MASS are used, a third field with the data heading ISOMER is used when isomer states are specified:

Decay data for each entry under ELEMENT/MASS(ISOMER) and their related parent or daughter nuclides may be given in the usual way under the information-identifier keyword DECAY-DATA. Entries under the data headings ELEMENT/MASS(ISOMER) are linked to entries under DECAY-DATA (and RAD-DET, if present) by means of a decay flag. [3]

Example: 

BIB
REACTION   (..(..,F)ELEM/MASS,IND,FY)
DECAY-DATA ((1.)60-ND-138,5.04HR,DG,328.,0.65)
           ((2.)60-ND-141,2.49HR,DG,.........)
ENDBIB
NOCOMMON
DATA
EN         ELEMENT    MASS       ISOMER     DATA       DECAY-FLAG
MEV        NO-DIM     NO-DIM     NO-DIM     PC/FIS     NO-DIM
           60.        138.                  ..         1.
           60.        140.                  ..         2.
..         61.        148.       0.         ..
..         61.        148.       1.         ..
..         61.        149.                  ..
..         62.        149.                  ..

Variable Number of Emitted Particles

If the data table contains yields or production cross sections as a function of the number of secondary particles, and the number of particles is entered as a variable in the data table, SF4 of the REACTION keyword contains the code NPART, SF5 contains the code NUM, and SF7 contains the particle considered.

Example: 

BIB
REACTION   (..(..,X)NPART,NUM,P)
..
ENDBIB
NOCOMMON
DATA
EN         PART-OUT   DATA
MEV        NO-DIM     B
..
..
..
ENDDATA

Reaction Combinations.For experimental data sets referring to complex combinations of materials and reactions, the code units defined in this section can be connected into a single machine-retrievable field, with appropriate separators and properly balanced parentheses. The complete reaction combination is enclosed in parentheses.

The following reaction combinations are defined:

((------)+(-----))Sum of 2 or more quantities.
((------)-(-----))Difference between 2 or more quantities.
((------)*(-----))Product of 2 or more quantities.
((------)/(-----))Ratio of 2 or more quantities.
((------)//(-----))Ratio of 2 quantities, where the numerator and denominator refer to different values for one or more independent variables.
((------)=(-----))Tautologies.

When a reaction combination contains the separator "//", the data table will contain at least one independent variable pair with the data heading extensions -NM and -DN.

Example: 

BIB
REACTION   (((92-U-238(N,F)ELEM/MASS,CUM,FY,,FIS)/
           (92-U-238(N,F)42-MO-99,CUM,FY,,FIS))//
           ((92-U-235(N,F)ELEM/MASS,CUM,FY,,MXW)/
           (92-U-235(N,F)42-MO-99,CUM,FY,,MXW)))
RESULT     (RVAL)
..
ENDBIB
COMMON
EN-DUM-NM  EN-DUM-DN
MEV        EV
1.0        0.0253
ENDCOMMON
DATA
ELEMENT    MASS       DATA
..
ENDDATA

Information Identifier Keywords

This section provides a listing of all information-identifier keywords, along with details about their use. The keywords appear in alphabetical order.

ADD-RES.

Gives information about any additional results obtained in the experiment, but which are not compiled in the data tables. Codes are given in Dictionary 20.

Example: 

ADD-RES    (RANGE) Range of recoils measured.

ANALYSIS.

Gives information as to how the experimental results have been analyzed to obtain the values given under the heading DATA which actually represent the results of the analysis. Codes are found in Dictionary 23.

Example: 

ANLAYSIS   (MLA) Breit-Wigner multilevel analysis

ASSUMED

Gives information about values assumed in the analysis of the data, and about COMMON or DATA fields headed by ASSUM or its derivatives. The format of the code is:

(heading,reaction,quantity)

Heading field: data heading to be defined.

Reaction field and quantity field: coded as under the keyword REACTION.

Example: 
ASSUMED   (ASSUM,6-C-12(N,TOT),,SIG)

AUTHOR.

Gives the authors of the work reported.

Example: 

AUTHOR    (R.W.McNally Jr,A.B.JONES)

COMMENT.

Gives pertinent information which cannot logically be entered under any other of the keywords available.

CORRECTION.

Gives information about corrections applied to the data in order to obtain the values given under DATA.

COVARIANCE.

Gives covariance information provided by the experimentalist, or to flag the existence of a covariance data file. See page 44 for covariance file format.

Example: 

COVARIANCE (COVAR) Covariance file exists and may be obtained on request.

CRITIQUE.

Gives comments on the quality of the data presented in the data table.

DECAY-DATA.

Gives the decay data for any nuclide occurring in the reaction measured as assumed or measured by the author for obtaining the data given [4] . The general format of the coding string consists of three major fields which may be preceded by a decay flag:

((decay flag)nuclide,half-life,radiation).

Flag. A fixed-point number that also appears in the data section under the data heading DECAY-FLAG. If the flag is omitted, its parentheses are also omitted.

Nuclide field.A nuclide code. For ground states, the use of the extension G is optional.

Half-life field.The half-life of the nuclide specified, coded as a floating-point number, followed by a unit code with the dimension of TIME.

Radiation field.Consists of three subfields: (type of radiation, energy, abundance). This field may be omitted, or repeated (each radiation field being separated by a comma). The absence of any subfield is indicated by a comma; trailing commas are not included.

SF1. Type-of-radiation.
A code from Dictionary 33. Where two or more different decay modes are possible and are not distinguished in the measurement, two or more codes are given; each separated by a slash. (See Example b below).
SF2. Energy.
The energy of the radiation in keV, coded as a floating-point number. In the case of two or more unresolved decays, two or more energies, or a lower and upper energy limit, are given, each separated by a slash. (See Example e).
SF3. Abundance.
The abundance of the observed per decay, coded as a floating-point number.

Example: 

a) DECAY-DATA (60-ND-140,3.3D)

(radiation field omitted) 

b) DECAY-DATA (59-PR-140,,B+/EC,,0.500)

(half-life and decay energy omitted) 

c) DECAY-DATA (25-MN-50-G,0.286SEC,B+,6610.)

(abundance omitted) 

d) DECAY-DATA ((1.)60-ND-138,5.04HR,DG,328.,0.065)

(decay flag, all fields present) 

e) DECAY-DATA (60-ND-139-M,5.5HR,DG,708./738.,0.64)

(the abundance given is the total abundance of both γ rays) 

f) DECAY-DATA (60-ND-139-G,30.0MIN,B+,,0.257,
                                   DG,405.,0.055)
              (60-ND-139-M,5.5HR,DG,738.,0.37,
                                 DG,982.,0.29,
                                 DG,708.,0.27,
                                 DG,403.,0.03,
                                 B+,,0.006)

DECAY-MON.

Gives the decay data assumed by the author for any nuclide occurring in the monitor reaction used. The coding rules are the same as those for DECAY-DATA, except that, instead of the flag field, there may be a heading field which links the data to the heading of the monitor value, if more than one monitors are given.

Example: 
DECAY-MON  ((MONIT1)26-SC-46-G,83.81D,DG,889.3,0.99984,
                                      DG,1120.5,0.99870)
           ((MONIT2)26-SC-47,3.345D,DG,159.4,0.683)

DETECTOR.

Gives information about the detector(s) used in the experiment. Codes are found in Dictionary 22. If the code COIN is used, then the codes for the detectors used in coincidence follow within the same parenthesis;

Example: 
DETECTOR   (COIN,NAICR,NAICR)

Similarly, the code PS (position-sensitive detector) will be followed by a specific detector code.

EN-SEC.

Gives information about secondary energies, and to define secondary-energy fields given in the data table. The format of the coded information is:

(heading,particle).

Heading Field.
Contains the data heading or the root of the data heading to be defined.
Particle Field.
Contains the particle or nuclide to which the data heading refers. The code is: either a particle code from Dictionary 13. or a nuclide code.
Example: 
EN-SEC    (E1,G)
          (E2,N)
          (E-EXC,3-LI-7)

ERR-ANALYS.

Explains the sources of uncertainties and the values given in the COMMON or DATA sections under data headings of the type ERR- or -ERR. The general code format is

(heading,correlation factor) free text

Heading Field.
Contains the data heading or the root [5] of the data heading to be defined.
Correlation Factor Field
contains the correlation factor, coded as a floating point number.
Example: 
BIB
...
ERR-ANALYS (EN-ERR) followed by explanation of energy error
           (ERR-T) followed by explanation of total uncertainty
           (ERR-S) followed by explanation of statistical uncertainty

EXP-YEAR.

Defines the year in which the experiment was performed when it differs significantly from the data of the references given (e.g., classified data published years later).

Example: 

EXP-YEAR   (1965)

FACILITY.

Defines the main apparatus used in the experiment. The facility code from Dictionary 18 may be followed by an institute code from Dictionary 3, which specifies the location of the facility.

Example: 

FACILITY   (CHOPF,1USACOL)
           (SPECC,1USABNL)

FLAG.

Provides information to specific lines in a data table, similar to a footnote.

Example: 

BIB
..
FLAG       (1.) Data averaged from 2 runs
           (2.) Modified detector used at this energy
ENDBIB
..
DATA
EN         DATA       FLAG
KEV        MB         NO-DIM
1.2        123.       1.
2.3        234.      
3.4        456.       2.
ENDDATA

HALF-LIFE.

Gives information about half-life values and defines half-life fields given in the data table. The general coding format is:

(heading,nuclide)

Example: 

HALF-LIFE  (HL1,41-NB-94-G)
           (HL2,41-NB-94-M)

HISTORY.

Documents the handling of an entry or subentry. The general format of the code is:

(yyyymmddX)

, where yyyymmdd is the date (year,month,day) and X is a code from Dictionary 15.

Example: 

HISTORY    (19940312C)
           (19960711A) Data units corrected.

INC-SOURCE.

Gives information on the source of the incident particle beam used in the experiment. Codes are found in Dictionary 19.

Example: 

INC-SOURCE (POLNS,D-T)
INC-SOURCE (MPH=(13-AL-27(N,A)11-NA-24))

INC-SPECT.

Provides free text information on the characteristics and resolution of the incident-projectile beam.

INSTITUTE.

Designates the laboratory, institute, or university at which the experiment was performed, or with which the authors are affiliated. Codes are given in Dictionary 3.

Example: 

INSTITUTE  (1USAGA, 1USALAS)
INSTITUTE  (2FR SAC)

LEVEL-PROP.

Gives information on the spin and parity of excited states. The general format of the code is

((flag) nuclide, level identification, level properties)

Flag. Coded as a fixed-point number that appears in the data section under the data heading LVL-FLAG. When the flag is omitted, its parentheses are also omitted.

Nuclide. Coded is a nuclide, except that the use of the extension G is optional.

Level identification. Identification of the level whose properties are specified, given as either a level energy or level number. If the field omitted, its separating comma is omitted.

Level Energy.
The field identifier E-LVL= followed by the excited state energy in MeV, coded as a floating-point number which also appears in the data section under the data heading E-LVL.
Level Number.
The field identifier LVL-NUMB= followed by the level number of the excited state, coded as a fixed-point number which also appears in the data section under the data heading LVL-NUMB.
Isobaric analog state number.
The level identifier IAS-NUMB= followed by the level number of the isobaric analog state, n, where n has a numerical value which also appears in the data section under the data heading IAS-NUMB.

Level properties. Properties for the excited state, each preceded by a subfield identification. At least one of the subfields must be present.

Spin.
The field identifier SPIN=, followed by the level spin coded as a floating point number. For an uncertain spin assignment, two or more spins may be given, each separated by a slash.
Parity.
The field identifier PARITY=, followed by the level parity, coded as e.g., +1. or -1.

Example: 

LEVEL-PROP (82-PB-206,E-LVL=0.,SPIN=0./1.,PARITY=+1.)
           (82-PB-206,E-LVL-1.34,SPIN+3.,PARITY=+1.)
LEVEL-PROP ((1.)82-PB-206,,SPIN=0./1.,PARITY=+1.)  
           ((2.)82-PB-206,,SPIN=3.,PARITY=+1.) 
LEVEL-PROP (82-PB-207,LVL-NUMB=2.,SPIN=1.5,PARITY=-1)

METHOD.

Describes the experimental technique(s) employed in the experiment. Codes are found in Dictionary 21.

Example: 

METHOD     (RCHEM) Radiochemical separation

MISC-COL.

Defines fields in the COMMON or DATA sections headed by MISC and its derivatives.

Example: 

MISC-COL   (MISC1) Free text describing 1st miscellaneous field
           (MISC2) Free text describing 2nd miscellaneous field

MOM-SEC.

Gives information about secondary linear momentum, and defines secondary-momentum fields given in the data table. The general code format is:

(heading,particle)

Heading Field:the data heading or root [6] of the data heading to be defined.

Particle Field:the particle or nuclide to which the data heading refers. The code is: either a particle code from Dictionary 33. or a nuclide code. 

MOM-SEC    (MOM-SEC1,26-FE-56)
           (MOM-SEC2,26-FE-57)

MONITOR.

Gives information about the standard reference data (standard, monitor) used in the experiment and defines information coded in the COMMON and DATA sections under the data heading MONIT, etc. The general coding format is

((heading) reaction)

Heading Field. Contains the data heading of the field in which the monitor value is given. If the heading is omitted, its parenthesis is omitted.

Reaction Field. The coding rules are identical to those for REACTION, except that subfields 5 to 9 may be omitted when only the reaction is known.

Example: 

MONITOR    (92-U-235(N,F),,SIG)

If more than one monitor is given, they are linked to the respective columns in the COMMON or DATA section either with pointers, or using the heading field.

Example: 

MONITOR    ((MONIT1)1-H-1(N,EL),,SIG)
           ((MONIT2)13-AL-27(N,A)11-NA-24,,SIG))

MONIT-REF.

Gives information about the source reference for the standard (or monitor) data used in the experiment. The general code format is

((heading)subaccession#,author,reference)

Heading Field:Data heading of the field in which the standard value is given. If the heading is omitted, its parentheses are also omitted.

Subaccession Number Field: Subaccession number for the monitor data, if the data is given in an EXFOR entry. Cnnnn001 refers to the entire entry; Cnnnn000 refers to a yet unknown subentry. This field may be omitted.

Author Field. The first author, followed by "+" when more than one author exists.

Reference Field. May contain up to 6 subfields, coded as under REFERENCE. References to evaluated data libraries are coded

(...,3,code-version,,date) or

(...,3,code-version,MAT-number,date) with a code from Dictionary 144 (Data Libraries).

Example: 

MONIT-REF  ((MONIT1)BOO17005,J.Goshal,J,PR,80,939,1950)
           ((MONIT2),A.G.Panontin+,J,JIN,30,2017,1968)
MONIT-REF  (,L.W.Weston+,3,JEFF-3.1,9228,2005)

PART-DET.

Gives information about the particles detected directly in the experiment. Particles detected in a standard/monitor reaction are not coded under this keyword. The code is either a code from Dictionary 33, or, for particles heavier than α particles, a nuclide code. Particles detected pertaining to different reaction units within a reaction combination are coded on separate records in the same order as the corresponding reaction units.

Example: 

PART-DET   (A)
PART-DET   (3-LI-6)

RAD-DET.

Gives information about the decay radiations (or particles) and nuclides observed in the reaction measured. The general format of the code is

((flag)nuclide, radiation).

Flag is a fixed-point number which appears in the data section under the data heading DECAY-FLAG. If the field is omitted, its parentheses are also omitted.

Nuclide contains a nuclide code.

Radiation contains one or more codes from Dictionary 33, each separated by a comma.

Example: 

RAD-DET    (25-MN-52-M,DG,B+)
RAD-DET    (48-CD-115-G,B-)
           (49-IN-115-M,DG)
RAD-DET    ((1.)48-CD-115-G,B-)
           ((2.)49-IN-115-M,DG)

REACTION.

Specifies the data presented in the DATA section in fields headed by DATA or a similar heading such as DATA-MAX, DATA-MIN. See preceding Chapter for details.

REFERENCE.

Gives information on references that contain information about the data coded. Other related references are not coded under this keyword (see REL-REF, MONIT-REF). The general coding format is

(reference type, reference, date).

The format of the reference field is dependent on the reference type. The general format for each reference type follows.

Type of Reference = B or C: Books and Conferences.

General code format: (B or C,code,volume,(part),page(paper #),date). Codes from Dictionary 7 (Conferences) or 207 (Books).

Example: 

(C,67KHARKOV,,(56),196702)

Kharkov Conference Proceedings, paper #56, February 1967. 

(C,66WASH,1,456,196603)

Washington Conference Proceedings, Volume 1, page 456, March 1966 

(B,ABAGJAN,,123,1964)

Book by Abagjan, page 123, published in 1964.

Type of Reference = J or K: Journals or Journal Abstracts.

General code format is (J,code,volume,(issue #),page,date). Codes are from Dictionary 5.

Example: 

(J,PR,104,1319,195612)

Phys. Rev. Volume 104, page 1319, Dec. 1956 

(J,XYZ,5,(2),89,196602)

Journals XYZ, Volume 5, issue #2, page 89, February 1966

Type of Reference = P or R or S: Reports (Progress, Lab, Conference Reports)

General code format: (P or R or S,code-number,date). Codes from Dictionary 6.

Example: 

(R,JINR-P-2713,196605)

Dubna report, series P, number 2713, May 1966. 

(P,WASH-1068,185,196603)

WASH progress report number 1068, page 185, March 1966.

Type of Reference = T, or W or X: Thesis or Private Communication or Preprint

General code format: (W or T or X,author,page,date)

The page field may be omitted, in which case the following comma is also omitted.

Example: 

(W,BENZI,19661104)

private communication from Benzi, November 4, 1966. 

(T,ANONYMOUS,58,196802)

thesis by Anonymous, page 58, February 1968.

REL-REF.

Gives information on references related to, but not directly pertaining to, the work coded. The general code format is:

(code,subaccession#,author,reference).

Code:code from Dictionary 17.

Subaccession #:EXFOR subaccession number for the reference given, if it exists. Cnnnn001 refers to the entire entry Cnnnn. Cnnnn000 refers to a yet unassigned subentry within the entry Cnnnn.

Author:first author, coded as under AUTHOR, followed by + when more than one author exists.

Reference:coded as for REFERENCE.

Example: 

(C,B9999001,A.B.NAME+,J,XYZ,5,(2),90,197701)

Critical remarks by A.B.Name, et al., in journal XYZ, volume 5, issue #2, p. 90, January 1977.

RESULT.

Describes commonly used quantities that are coded as REACTION combinations. Codes from Dictionary 37.

Example: 

REACTION   ((Z-S-A(N,F)ELEM/MASS,CUM,FY)/
           (Z-S-A(N,F)MASS,CHN,FY))
RESULT     (FRCUM)

SAMPLE.

Used to give information on the structure, composition, shape, etc., of the measurement sample.

STATUS.

Gives information on the status of the data presented. Entered in one of the general code formats, or, for cross reference to another data set, the general code format is: (code,subaccession#)

Code: code from Dictionary 16.

Subaccession# Field: cross-reference to an EXFOR subaccession number.

Example: 

STATUS (SPSDD,10048009)

- this subentry is superseded by subentry 10048009.

TITLE.

Gives the title for the work referenced.

Covariance Data File Format

Covariance data may be stored on a separate covariance file. This is mandatory if

  1. the file is too big to be included conveniently as free text within the EXFOR entry (under the keyword COVARIANCE); and/or
  2. the file is in a format which does not fit within columns 12 - 66 available for free text (e.g. ENDF-6 File 33 format).

The covariance file is named

aaaaasss.cov

with aaaaa being the accesssion number, sss the subentry number of the corresponding subentry (e.g. 35001002.cov).

There are three record types in the covariance file:

The actual covariance data can be given either in a free format, defined in the comment records, or in ENDF-6 File 33 format. In the latter case, the cross section may be included also (in File 3 format) for easy processing.

Comment record format

Column1 C
2 - 9 Data set number (subaccession number)
10 (blank)
11- 80Comment which includes covariance type and format

Data record format

a) Free format:

Column1 D
2 - 9 Data set number (subaccession number)
10 (blank)
11- 80Data in format given on comment record

b) ENDF 6 File 3/33 format:

First record:

Column1 F
2 - 9 Data set number (subaccession number)
10 (blank)
11- 14MAT number used
15 (blank)
16- 25File numbers given, separated by commas (e.g. 3,33)
26- 80Comment

Following records:

Column1- 80 As in ENDF-6

End record format

Column1 D
2 - 9 Data set number (subaccession number)
10- 80(blank)

Example 1: Covariance data in free format as defined in comment records 

C10034002 Values given only for elements below diagonal of
C10034002 symmetric matrix on same energy grid as data
C10034002 format.
C10034002 FORMAT(9E5.2)
D10034002 1.0
D10034002 0.98 1.0
D10034002 0.90 0.97 1.0
D10034002 0.70 0.82 0.93 1.0
D10034002 0.54 0.68 0.83 0.96 1.0
D10034002 0.64 0.75 0.85 0.92 0.95 1.0
E10034002

Example 2: Cross section and Covariance data in ENDF-6 File 3/33 format

[1] These are states with a measurable half-life of less than 0.1 seconds

[2] Note that the particle considered is not necessarily identical to the particle detected, e.g., the angular distrib ution of an outgoing particle which has been deduced from a recoil particle detected.

[3] If the half-life is the only decay data given, this may be entered in the data table under the data heading HL, al though this is not recommended.

[4] Decay data relevant to the monitor reaction are coded under the keyword DECAY-MON and not under DECAY-DATA.

[5] Root means that the data heading given also defines the heading preceded by + or -.

[6] Root means that the data heading given will also define the same heading followed by -MIN, -MAX or -APRX.