**1. NAME AND TITLE**

SWAN: Code System for Analysis and Optimization of Fusion Reactor Nucleonic
Characteristics.

**AUXILIARY ROUTINES**

AREAD: Input Data Processor.

LIBMAK: ANISN-Type Binary Data Library Manipulator

PPL-ANISN/SWAN Library Processor: Data Generator.

PPL-ANISN: One-Dimensional Discrete Ordinates Radiation Transport Module.

SIZERS: Storage Requirement Calculator.

SWIF: Perturbation Calculation and Optimization Module.

This code system combines the perturbation theory code SWIF and the transport theory code
ANISN with a control program for automatic iteration. Three auxiliary routines are also packaged
separately as: PSR-87/LIBMAK, PSR-88/AREAD and CCC-253/ANISN-PPL.

**2. CONTRIBUTOR**

Fusion Reactor Design Division, Plasma Physics Laboratory, Princeton University, Princeton,
New Jersey.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN IV; IBM 360/370.

**4. NATURE OF PROBLEM SOLVED**

Given the material density profiles which describe a one-dimensional reference system with a
neutron source, SWAN will calculate, and optionally implement, density changes so as to optimize
a single functional parameter of the system.

**5. METHOD OF SOLUTION**

The one-dimensional discrete-ordinate transport code ANISN is used to calculate flux and
adjoint distributions for specified sources. SWIF calculates first-order estimates of the effect of
material density changes on a goal functional, and from these evaluates effectiveness functions for
the substitution of one material for another. Density distribution changes are then calculated which
would optimize the goal functional, optionally subject to a constraint of holding another functional
constant (to first order).

**6. RESTRICTIONS OR LIMITATIONS**

SWAN is not designed to analyze critical systems; it assumes that there is a fixed source, as in
shielding or fusion reactor applications. Otherwise it is compatible with ANISN. All arrays are
variably-dimensioned, so that there are no restrictions on individual dimensions.

**7. TYPICAL RUNNING TIME**

It is difficult to choose a "typical" problem; the simple sample case executes in 6 seconds on
the IBM 360/91 computer. The bulk of the time is spent evaluating the fluxes and adjoints in
ANISN.

**8. COMPUTER HARDWARE REQUIREMENTS**

SWAN is operable on the IBM 360/370 computers. The following table represents RSIC
experience:

Running

Code Time Region I-O Units

AREAD TEST 6. sec. (75) 54 K 2

LIBMAK 1.9 sec. (91) 184 K 6

Library Processor 0.5 sec. (91) 72 K 4

ANISN 2.8 sec. (91) 166 K 9

SIZER 0.3 sec. (75) 54 K 2

SWIF 4.8 sec. (91) 188 K 14

**9. COMPUTER SOFTWARE REQUIREMENTS**

The codes are operable on the IBM 360/75/91 Operating System using an OS-360 FORTRAN H compiler.

ANISN and SWIF are processed using the OVERLAY feature.

**10. REFERENCES**

W. G. Price, Jr., "Notes on Installing the SWAN Package."

E. Greenspan, W. G. Price, Jr., and H. Fishman, * *"SWAN: A Code for the Analysis and
Optimization of Fusion Reactor Nucleonic Characteristics," MATT-1008 (November 1973).

W. G. Price, Jr., "A Revised Version of the ANISN Code," MATT-1035 (April 1974).

W. G. Price, Jr., "AREAD, An Input Data Processing Routine," MATT-1034 (March 1974).

W. G. Price, Jr., "LIBMAK: A Program to Manipulate ANISN-Type Binary Libraries," MATT-1036 (March 1974).

E. Greenspan, "A Method for the Optimization of Fusion Reactor Neutronic Characteristics,"
MATT-981 (April 1973).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced documents and one (1.2MB) DOS diskette which contains the
source code and sample problem input, and output from the sample problem.

**12. DATE OF ABSTRACT**

August 1975, revised April 1990.

**KEYWORDS**: OPTIMIZATION; NEUTRON; GAMMA-RAY; DISCRETE ORDINATES; ONE-DIMENSION