LEXFOR H HALFLIVES HALFLIFE VALUES IN EXFOR ENTRIES

LEXFOR H HALFLIVES HALFLIFE VALUES IN EXFOR ENTRIES




Half-lives

LEXFOR

H

Half-lives

Half-life values in EXFOR entries may define an isomeric state, or they may be basic parameters for deducing the data value from the experiment.


Half-lives may be coded in one of the following ways.

  1. In the BIB section using the keyword DECAY-DATA (see Decay Data). This is the preferred method for the following:

    • for metastable states in all nuclei involved in a reaction,

  1. When the half-life is a variable for the data presented, e.g., delayed neutron groups, it must be coded in the COMMON or DATA section using data headings from Dictionary 24 with the family code 6, e.g., HL, HL11. These are linked to the BIB keyword HALF-LIFE (see below).

If more than one half-life is given, the relevant nuclei must be coded under this keyword. If only one half-life value is given under the data heading HL with no explanation, then it refers to the half-life of the residual nucleus.

NLEXFOR H HALFLIVES HALFLIFE VALUES IN EXFOR ENTRIES umerical uncertainties may be entered using data headings from Dictionary 24 with the family code 7, e.g., HL-ERR, with a free text explanation under ERR-ANALYS; see EXFOR Exchange Formats Manual, ERR-ANALYS.

Example:

BIB


REACTION

(…(N,F),DL/GRP,NU)

…


ENDBIB


COMMON






HL

DATA





SEC






…

…





ENDCOMMON






LEXFOR H HALFLIVES HALFLIFE VALUES IN EXFOR ENTRIES

See EXFOR Exchange Formats Manual Chapter 4 for the repetition of the data heading HL in coding half-lives in different units.


ILEXFOR H HALFLIVES HALFLIFE VALUES IN EXFOR ENTRIES nformation-identifier keyword half-life: used to explain to which nucleus a half-life value given in the COMMON or DATA section refers. The coded information contains the data-heading keyword used and the relevant nucleus. (See EXFOR Exchange Formats Manual Chapter 7: HALF-LIFE, for coding details).

The free text should include the source of the half-life value, if known.

History

The information-identifier keyword HISTORY is used to document the chronological handling of the work within a data center. In particular, important corrections or revisions to an entry or subentry must be documented under HISTORY.


TLEXFOR H HALFLIVES HALFLIFE VALUES IN EXFOR ENTRIES he coded information consists of a date and a one-character code, and is followed by free text. (See EXFOR Exchange Formats Manual Chapter 7: HISTORY, for coding details; see Dictionary 15 for list of codes).


Important alterations are flagged with the code A in order to automate, as far as possible, follow-up actions resulting from the alteration, such as informing users who have received an earlier version. The following items are considered sufficiently important to be flagged with the code A:


Less important changes that the compiler wishes to document may be flagged by the code U.2


Examples of possible entries under the HISTORY keyword

(19671119R) Data received from author on tape

(19680220L) Data entered into library

(19690411C) AB

(19691015R) Data on tape ND 1234 from Ribon.3

(19691223) Proof copy sent to author

(19701003T) Data converted from SCISRS-I, and checked for agreement with table 3 in Phys. Rev. 56, p. 784

(19721130A) Some errors in data table corrected

(19721130U) Spelling error in BIB corrected


The rules concerning BIB information apply to HISTORY, i.e., an entry under history in the common subentry (SAN=1) applies to all other subentries and should not be repeated in the data subentries.


1 For the decay of a nucleus, the use of DECAY-DATA is preferred.

2 Compilers are urged to document all changes under HISTORY

3 The origin of the numerical data may be given here or under STATUS.

4 For data converted from another data library, see also Status.

February 2008 1





Tags: entries may, possible entries, entries, halflives, values, lexfor, halflife, exfor