1 | |
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2 | This README file provides instructions for reading the radioactive decay |
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3 | schemes in the files zXX.aYYY found in the directory RadioactiveDecay3.2 |
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4 | (most recent version). This directory, as well as previous versions, is |
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5 | available from the Geant4 download page |
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6 | |
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7 | http://geant4.web.cern.ch/geant4/support/download.shtml |
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8 | |
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9 | under the Data files heading. In order to use the radioactive decay module |
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10 | correctly, you must download and unpack the above directory in your local |
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11 | area, and set the environment variable |
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12 | |
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13 | G4RADIOACTIVEDATA |
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14 | |
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15 | to point to it. |
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16 | |
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17 | ************************************************************************** |
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18 | In each of the files, lines beginning with either a 'W' or a '#' are |
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19 | comments. |
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20 | |
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21 | Lines beginning with a 'P' are headers, each of which describes a level of |
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22 | the nucleus. The first number is the excitation energy in keV, the second |
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23 | is the half life in seconds. Indented lines under the 'P' lines are decay |
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24 | modes for that excitation. There are two type of records here, |
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25 | distinguished by the number of columns. |
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26 | |
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27 | If there are 3 columns only, this is a header which describes all decays of |
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28 | that type from this level. The first column is the decay mode, the second |
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29 | column is zero, and the third column in the branching ratio to this mode, |
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30 | as a fraction of unity. Therefore, the third columns of all the 3-column |
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31 | records under a given 'P' line should sum to 1.0. |
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32 | |
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33 | If there are four columns, this is a record which describes a subset of the |
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34 | decay type, specific to a given lower level in the daughter species. The |
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35 | first column is the decay type, the second column is the excitation level |
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36 | of the daughter (in keV), and the third column is the branching ratio as a |
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37 | percentage (! note... not a fraction of unity) of the total branching ratio |
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38 | which came from the 3-column record for this decay. |
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