| Geant4 Cross Reference |
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2 This README file provides instructions for rea 2 This README file provides instructions for reading the radioactive decay
3 schemes in the files zXX.aYYY found in the dir 3 schemes in the files zXX.aYYY found in the directory RadioactiveDecay3.2
4 (most recent version). This directory, as wel 4 (most recent version). This directory, as well as previous versions, is
5 available from the Geant4 download page
5 available from the Geant4 download page
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7 http://geant4.web.cern.ch/geant4/support/downl 7 http://geant4.web.cern.ch/geant4/support/download.shtml
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9 under the Data files heading. In order to use 9 under the Data files heading. In order to use the radioactive decay module
10 correctly, you must download and unpack the ab 10 correctly, you must download and unpack the above directory in your local
11 area, and set the environment variable
11 area, and set the environment variable
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12
13 G4RADIOACTIVEDATA
13 G4RADIOACTIVEDATA
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15 to point to it.
15 to point to it.
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17 ********************************************** 17 **************************************************************************
18 In each of the files, lines beginning with eit 18 In each of the files, lines beginning with either a 'W' or a '#' are
19 comments.
19 comments.
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21 Lines beginning with a 'P' are headers, each o 21 Lines beginning with a 'P' are headers, each of which describes a level of
22 the nucleus. The first number is the excitati 22 the nucleus. The first number is the excitation energy in keV, the second
23 is the half life in seconds. Indented lines un 23 is the half life in seconds. Indented lines under the 'P' lines are decay
24 modes for that excitation. There are two type 24 modes for that excitation. There are two type of records here,
25 distinguished by the number of columns.
25 distinguished by the number of columns.
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27 If there are 3 columns only, this is a header 27 If there are 3 columns only, this is a header which describes all decays of
28 that type from this level. The first column i 28 that type from this level. The first column is the decay mode, the second
29 column is zero, and the third column in the br 29 column is zero, and the third column in the branching ratio to this mode,
30 as a fraction of unity. Therefore, the third 30 as a fraction of unity. Therefore, the third columns of all the 3-column
31 records under a given 'P' line should sum to 1 31 records under a given 'P' line should sum to 1.0.
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33 If there are four columns, this is a record wh 33 If there are four columns, this is a record which describes a subset of the
34 decay type, specific to a given lower level in 34 decay type, specific to a given lower level in the daughter species. The
35 first column is the decay type, the second col 35 first column is the decay type, the second column is the excitation level
36 of the daughter (in keV), and the third column 36 of the daughter (in keV), and the third column is the branching ratio as a
37 percentage (! note... not a fraction of unity) 37 percentage (! note... not a fraction of unity) of the total branching ratio
38 which came from the 3-column record for this d 38 which came from the 3-column record for this decay.