Experimental Nuclear Reaction Data
- Introduction
- EXFOR database contents
- Brief description of the EXFOR format
- Complete description of the EXFOR format
- Search the database
- Search the EXFOR database
Introduction
EXFOR database contents
EXFOR is the name given to the database containing experimental data. In addition to storing the data and its bibliographic information, experimental information, including source of uncertainties, is also compiled.
The data presently included in the EXFOR database include:
- a "complete" compilation of experimental neutron-induced reaction data;
- a selected compilation of charged-particle induced reaction data;
- a selected compilation of photon-induced reaction data.
Brief description of the EXFOR format
EXFOR is also the name of the exchange format designed to allow transmission of nuclear data between the Nuclear Reaction Data Centres. It has evolved to allow a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in an easily machine-readable format.
An EXFOR entry (or "work" as it is commonly known) is divided into bibliographic and descriptive information (alphanumeric) and data (numeric). The entries are further divided into subentries (data sets). Bibliographic or descriptive information and common data may be associated with the whole entry and/or with each subentry. A set of system identifiers has been devised for separating these logical blocks of information within an entry.
- A set of information identifiers (keywords) has been devised so that each item of bibliographic information may be identified for computer processing.
- Each piece of bibliographic or descriptive information may have associated with it a standard set of codes. These codes, enclosed in parentheses, may be used, for example for retrieval or for identifying a data set. A set of dictionaries is provided for defining the meaning of those codes which are not self-explanatory.
- Unlimited free text is permitted with each information identifier.
- The data for a subentry are presented in the form of a table of fixed field widths, but with no positional meaning. Each table is preceded by its data heading and data units; dictionaries are provided to define a standard set of heading and unit codes.
Complete description of the EXFOR format
For a complete description of the EXFOR format, including examples, and the use of keywords please see the EXFOR Basics Manual produced by the National Nuclear Data Center at Brookhaven National Laboratory, USA on behalf of the Nuclear Reaction Data Centres.
Search the database
Tips on searching the EXFOR database
There are two web pages to choose from: the Simple Exfor form, which is the main search page and the Advanced Exfor form with more parameters for a precise search.
Step 1: Enter the search criteria
The EXFOR web retrieval system provides an easy way to make searches of the EXFOR database. To specify a nuclide, enter either the Atomic Number (Z) or Symbol (or a list, separated by commas but no spaces e.g. 3,4 or Li,Be). Likewise, enter the Atomic Mass (A).
The reaction is specified either by selecting values from the scrolling lists of permissible values for Particle, Process, Branch and Parameter, or by entering the reaction string in the space provided. The reaction is broken down into eight subfields as follows:
sf1 (sf2, sf3) sf4, sf5, sf6, sf7, sf8, sf9
where:
| sf1 - | target isotope |
| sf2 - | incident particle |
| sf3 - | product particle |
| sf4 - | reaction process |
| sf5 - | branch code |
| sf6 - | parameter code |
| sf7 - | particle considered |
| sf8 - | modifier code |
| sf9 - | data type |
In addition to the nine subfield specifiers listed above, the energy range of the data and a range of years of publication may be provided as search crietria. Alternatively, if the EXFOR work number is already known, this may be entered in preference to all other search parameters.
The database search is initiated by clicking on the Retrieve button.
Step 2: Retrieve the data
An index of the available data corresponding to the specified search criteria will be displayed. This shows the unique EXFOR work number, the nuclide name and mass, the reaction described in the data set, the energy range of the data in the data set, the laboratory where the measurement was performed and the year of publication. If you are satisfied that these data meet your requirements, then the data may be retrieved by clicking on the View Exfor result button.
Alternatively, each EXFOR work may be retrieved individually by clicking on the EXFOR work number.
Step 3: Plot the data
The data can be saved in the tabular/computational format, which is useful for third party plotting packages. Use the "Generate tabular data format" button for that. The EXFOR data can also be plotted using JANIS, the Java based display software that has been developed at the NEA.
Last update: 30 September 2010
