1. NAME AND TITLE

SC2N3N: Systematics of (n,2n) and (n,3n) Cross Sections.

2. CONTRIBUTORS

Institute of Atomic Energy, Beijing, China, through the International Atomic Energy Agency, Vienna, Austria, and the NEA Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; VAX family.

4. NATURE OF PROBLEM SOLVED

SC2N3N can be used to calculate the (n2n) and (n3n) cross section in the energy region from threshold to about 25 MeV with the systematics parameters which well reproduce the experiment in the mass region of 23.le.A.le.238 (especially between 45 and 197.)

5. METHOD OF SOLUTION

The parameterized formulas for fitting measured data and getting local parameters are based on the constant temperature evaporation model and the exciton model under some approximations. For the (n,2n) and (n,3n) reaction, the projectile neutron can be emitted from the direct reaction, the pre-equilibrium emission and the compound decay. Only inelastic scattering is considered in direct reaction for (n,2n); direct reaction is neglected in (n,3n) reactions.

6. RESTRICTIONS OR LIMITATIONS

The number of energy points should be less than 200.

7. TYPICAL RUNNING TIME

The sample input took only a few seconds on a VAX 6000 under the VAX/VMS operating system.

8. COMPUTER HARDWARE REQUIREMENTS

The code will run on the VAX family of computers.

9. COMPUTER SOFTWARE REQUIREMENTS

The code is Fortran 77 and uses the VAX/VMS Fortran compiler.

10. REFERENCES

Zhang Jin, Zhou Delin, Cai Dunjiu, Systematics of (n,2n) and (n,3n) Cross Sections, Institute of Atomic Energy, Beijing, China, IAEA-0917.

Wang Zisheng and Cai Dunjiu, ``Systematics of (n,2n) and (n,3n) Reaction Cross Sections,'' 436--445 in JAERI-M 91-032.

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one DS/DD (360 K) 5.25 inch diskette.

12. DATE OF ABSTRACT

January 1992.