The format for `mcf.asc'

The purpose of the code mcfgen is to produce an ASCII file `mcf.asc'. The information in this file is used by the code mcfbin to produce a binary file `mcf.bin' for use in all-particle Monte Carlo codes. The `mcf.asc' file begins with two introductory lines, followed by a loop over the targets. For each target the first few lines provide its identity and some basic information, including a list of the reactions. The first target is special, in that its data starts with the energy group boundaries and the temperature.

For each of the targets we have a loop over the reactions, and for each reaction the file contains data for various reaction properties, such as cross section, angular distribution of secondary particles, or their energy distribution. Each of these data blocks is preceded by an identification flag and a header, and this flag and header information are essential to the mcfbin code. The end of the data for a target is marked by a flag (the number 99).

The notification for the end of the file is a particular phoney target ZA = 999999.

In summary, the form of an `mcf.asc' file is as follows.

First line:

The date this `mcf.asc' file was created, and its type.

Second line:

Identify the library source and the date of the latest modification of the library.

Loop over the target nuclei.

Identify the target:

A new target is marked by ` *' at the end of the line. The rest of the line contains this target's atomic number and mass number, the number of incident energy groups, and the number of reactions.

Basic target data:

Identify the incident particle, the halflife, the excitation level of the target, the temperature of the target, the target's atomic mass, and the library date.

List the reactions:

Next in the file follows the list of values of the C reaction identifier for this target.

For the first target:

If this is the first target in the `mcf.asc' file, then come the energy groups and the target temperature as follows.

Energy group block:

One line for the energy-group flag and the number of groups. Then come the energy group boundaries.

Temperature block:

This option exists in case we someday implement Doppler broadening inside mcfgen. For now, there is just one target temperature. The file has one line for the temperature flag and the number of temperatures, and it has another line for the temperature.

Loop over the reactions:

We go through the reactions for this target.

Loop over the data for a reaction:

For each reaction for this target there are various blocks of data, given by increasing value of I_number. Each block is of the following form. The first line of the block starts with the flag for the type of data, and it may have other information. The second line is a header giving the amount of data and further identification of the data. The data then follows.

Flag 99:

A special flag marks the end of data for a target.

End of file:

The phoney target 1000*Z + A = 999999 marks the end of the file.