Reaction directories

Each reaction directory contains such things as the identity of the reaction, plus a list of the secondary particles and their atomic masses. It also gives data locations relative to the start of the data for this target. This reference point is given in the target directory.

1:

The length of the reaction directory (22 plus 2 times the number of secondary particles for the reaction plus the number given in item 17 below).

2:

The date of the latest modification, with 10 March 1993 coded as 930310.

3:

The C reaction identifier. See Section 2.2.

4:

The S reaction switch, to tell the meaning of the variable x1, item 13 on this list. See Section 2.3.

5:

The atomic number and mass number of the target, coded as 1000*Z + A.

6:

The number of entries in the cross-section table ( $\tt I\_number$ = 0).

7:

The location of the cross-section table.

8:

The index of the energy group for the first nonzero cross section. This amounts to an energy threshold.

9:

The index of the energy group for the last nonzero cross section. This amounts to a maximum energy.

10:

The location of the data on total available energy. The number of entries is the same as the number of cross sections, and it is given in item 6.

11:

Unused.

12:

The energy of the reaction q0 in Mev, computed from the mass balance.

13:

The parameter x1, with meaning specified by the switch S given in item 4 above. This is commonly the excitation level.

14:

The number of products, not including photons, but including residual nucleus when that is appropriate.

15:

The location in the reaction directory of the list of product atomic numbers and mass numbers 1000*Z + A, relative to the start of the first reaction directory for this target.

16:

The location in the reaction directory of the list of product atomic weights, relative to the start of the first reaction directory for this target.

17:

The number of additional offsets. This number is currently one, to provide a slot for the location of energy production data for production cross section reactions ( $\tt C$ = 5).

18:

The location of the additional offsets, relative to the start of the first reaction directory for this target.

19:

The kinematics type. This is one of the numbers 0, 1, ... 7, and its significance is explained in Section 2.5.

20:

The location of the kinematics directory for this reaction, relative to the start of the target directory.

21:

The length of the kinematics directory for this reaction.

22:

The number of secondary particles for this reaction, including photons and not including a residual nucleus.

Particles:

What follows is a list of the numbers 1000*Z + A for the secondary particles produced by the reaction, including the residual nucleus but not photons. The location of this list is also given by item 15 above. Multiple particles are listed repeatedly, according to their number.

Atomic masses:

The particle list is followed by a list of their atomic masses, and the location of the first atomic mass is given by item 16 above.

Additional descriptors:

Finally, we have the location of the energy production data for the $\tt C$ = 5 reaction. For other reactions this entry is zero.