| 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 RadioactiveDecay5.0
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://cern.ch/geant4/support/download.shtml
7 http://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.
16
16
17 ********************************************** 17 **************************************************************************
18 In each of the files, lines beginning with '#' 18 In each of the files, lines beginning with '#' are comments.
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20 Lines beginning with a 'P' are headers, indica 20 Lines beginning with a 'P' are headers, indicating metastable states of the
21 nucleus which may be parent nuclei for further 21 nucleus which may be parent nuclei for further decays. The first number is
22 the excitation energy in keV, followed by a ch 22 the excitation energy in keV, followed by a character representing the floating
23 level. If this is "-", the level is assumed t 23 level. If this is "-", the level is assumed to be fixed. If it is
24 +X, +Y, +Z, +W, +U or +V, the level is floatin 24 +X, +Y, +Z, +W, +U or +V, the level is floating, or undetermined. The number
25 following this is the half life in seconds. I 25 following this is the half life in seconds. Indented lines under the 'P' lines
26 are decay modes for that excitation. There ar 26 are decay modes for that excitation. There are two types of records here,
27 distinguished by the number of columns.
27 distinguished by the number of columns.
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29 If there are four columns only, this is a head 29 If there are four columns only, this is a header describing the total strength
30 of each type of decay from this level. The fi 30 of each type of decay from this level. The first column is the decay mode,
31 the second column is always zero, the third co 31 the second column is always zero, the third column indicates whether the level
32 is floating or not, as mentioned above, and th 32 is floating or not, as mentioned above, and the fourth column is the total
33 branching ratio going through this mode, as a 33 branching ratio going through this mode, as a fraction of unity. Therefore,
34 the fourth column of all the 4-column records 34 the fourth column of all the 4-column records under a given 'P' line should sum
35 to 1.0.
35 to 1.0.
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37 If there are five columns, this is a record wh 37 If there are five columns, this is a record which describes a subset of the
38 decay type, specific to a given lower level in 38 decay type, specific to a given lower level in the daughter species. The
39 first column is the decay type, the second and 39 first column is the decay type, the second and third columns are the excitation
40 level (keV) of the daughter reached after the 40 level (keV) of the daughter reached after the decay and its floating level
41 indicator, and the fourth column is the branch 41 indicator, and the fourth column is the branching ratio as a percentage
42 (! note... not a fraction of unity) of the tot 42 (! note... not a fraction of unity) of the total branching ratio which came
43 from the 4-column record for this decay.
43 from the 4-column record for this decay.
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45 In the case of beta- or beta+ decay, there wil 45 In the case of beta- or beta+ decay, there will often be a sixth column
46 describing the "forbiddenness" of the particul 46 describing the "forbiddenness" of the particular decay channel. This is
47 indicated by the tags firstForbidden, secondFo 47 indicated by the tags firstForbidden, secondForbidden, thirdForbidden,
48 uniqueFirstForbidden, uniqueSecondForbidden, u 48 uniqueFirstForbidden, uniqueSecondForbidden, uniqueThirdForbidden, which
49 determine the shape of the beta spectrum.
49 determine the shape of the beta spectrum.
50 ********************************************** 50 **************************************************************************
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