ALARA output is always written to the standard output of the system in question. The standard methods of your system should be used to capture this output to a file, if desired. A sample output is available here.

As described in the section on command-line arguments, various levels of output are available during the calculation. The first part of the output file will contain this verbose output, including confirmation of the input data and details of the cross-referencing and preprocessing of the input.

The second part of the output file shows details on the tree building process, ranging from a simple list of the root isotopes being solved and statistics on the size and speed of the solution, to details on the chain growth and truncation calculations (depending on the verbosity specified on the command-line).

The final part of the output files are the results, as requested by the user in the input file. This output will include one section for each output format description given by the user. Each of these sections will be divided into blocks as shown in the following block diagram.

ALARA also optionally produces a so-called tree file to allow some rudimentary pathway analysis. The tree file contains much information about the creation and truncation of the trees and chains used to calculate the transmutation and activation in the problem.

One tree will be created for each initial isotope. All the information given for this isotope is based on the flux chosen for the truncation calculations of this isotope, namely, the group-wise maximum flux across all the intervals in which the initial isotope exists. An entry for an isotope in the tree will look like this:

-(na)->h-3 - (0.00306937)

The level of indentation indicates the rank of this isotope:doc:[G] <glossarytext> in the tree. This can be best seen by viewing the whole file and noting the line’s relative indentation. The information given in such an entry is as follows:

reaction type: (na)

This indicates the reaction type(s).

If multiple reactions lead to this product, the reactions will be separated by commas. The information indicates the emitted particles only. Therefore, in this example, the reaction is an (n,na) reaction. Generally, standard symbols are used, such as ‘n’ for neutrons, ‘a’ for alpha particles, ‘p’,’d’,’t’ for the three isotopes of hydrogen, respectively, and ‘h’ for helium-3. For all neutron reactions, an additional ‘ * ‘ is used to indicate that the product is in an excited isomeric state. Finally, for decay reactions the symbol ‘ * D’ is used.

product nuclide: h-3

The product isotope’s chemical symbol and atomic number.

In cases where the product is in an isomeric state, this will be followed by a letter (m,n,…) indicating which isomeric state.

truncation mode: - This single character indicates the result of the truncation calculation at this node.

There are four possible results as follows:

Result Description

- This code indicates that the chain continues normally

because this isotope passed all the tests.

* This code indicates that only the radioactive decays

of the chain will be followed after this node. This arises when the production does not pass the truncation tolerance test, but ensures that the result includes all the radioactive products. Stable products which are descendants of this node may be calculated if they themselves pass the ignore tolerance test.

/ This code indicates that the chain will be fully

truncated at this node, and the result will include this node. This arises when the node is a stable isotope and does not pass the truncation tolerance test, but does pass the ignore tolerance test.

< This code indicates that the chain will be fully

truncated at this node and will not be included in the result. This arises when the production of this nuclide does not pass either the truncation or the ignore tolerance test.

truncation production: (0.00306937)

This indicates the relative production at the end of operation of this nuclide from the initial isotope during the truncation calculation.

As explained in the ALARA Technical Manual], this represents the total production of this nuclide during the whole problem, assuming that none of it is transmuted or decays further. If this production is not calculated, for example, because the chain is only being followed on radioactive reactions and this nuclide is stable, then this entry will be ‘-‘.

The gamma source files created by ALARA currently has a very simple (if not unweildy) format. This file is only created if the photon_src option is used in one of the output blocks of the input file where the filename is also given. The spatial resolution of this file is that specified by the output block.

For each spatial region, there is a section for each isotope responsible for gamma emissions and a section for the total gamma emissions. Each of these sections has a header line consisting of the isotope’s identifier (chemical symbol and mass number) or the keyword “TOTAL”, respectively. Within each section, there is one block of gamma source values for each output time, that is, one for shutdown and one for each cooling time. Finally, each of these blocks contains the group-wise gamma source values in photons per second, arranged in lines of 6 values per line.