IAEA0953: BASACF, Integral Neutron Spectra Adjustment and Dosimetry

OECD Nuclear Energy Agency / L'Agence pour l'énergie nucléaire

OECD-OCDE

[Program Service | Recent programs]

IAEA0953 BASACF. (Abstract last modified 27-MAR-1996)

BASACF, Integral Neutron Spectra Adjustment and Dosimetry

Abstract Table of Contents:

OPERATING SYSTEM

OTHER RESTRICTIONS

1. NAME OR DESIGNATION OF PROGRAM - BASACF.

2. COMPUTER FOR WHICH PROGRAM IS DESIGNED AND OTHER MACHINE VERSION PACKAGES AVAILABLE -

To request or retrieve programs click on the one of the active versions below. A password and special authorization is required.

Explanation of the status codes.

Program-name Package-ID Status BASACF IAEA0953/01 Obsolete BASACF IAEA0953/02 Tested

Machines used: Package-ID Orig.Computer Test Computer IAEA0953/02 Many Computers Many Computers

3. DESCRIPTION OF PROGRAM OR FUNCTION - Adjustment of a neutron spectrum based on integral detector measurements and calculation of an integral dosimetric quantity (integral flux, d.p.a., dose equivalent) and its variance. The program requires measured data (activities and their covariance matrix) and apriori information (spectrum, dosimetry cross sections, integral quantity conversion factor and their covariance matrices). ALL apriori covariance matrices can be read in from a file prepared by some other code or can be generated by means of three different methods (by subroutines included in the program). A subroutine which can normalize the apriori flux to measured data is also included.
The program provides also adjusted domisetry cross sections (with covariance matrix) so that it can be used for an adjustment of cross sections (or response functions of e.g. Bonner balls) by measurements in well-known neutron spectra.

4. METHOD OF SOLUTION - Bayesian theorem on conditional probability applied to linearized relation between activities, dosimetry cross sections and flux. All probability distributions are supposed to be normal and this supposition leads to minimizing of the same functional as least squares method (STAY'SL). This task is solved by a covariance filter method which avoids any matrix inversion and is numerically robust and stable.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - This version can use 45 energy groups and 5 detectors and occupies 310 KB of main memory. This restriction can be modified according to available memory.
The covariance matrix of activities is supposed diagonal.
A solution is produced for any set of input data but in the case of non-consistent data, when measured activities do not match the apriori flux, the solution is not very meaningful.

6. TYPICAL RUNNING TIME - The adjustment of one spectrum with ready covariance matrices takes approximately 90 s. Generation of an apriori covariance matrix of 5 detectors in 45 groups depends on the used method: 9 min for block (STAY'SL) and Gaussian methods and 70 min for AILDV method. This time is relative to the ES-4 computer. Typical time on DEC-VAX 6000 is between 8-24 seconds.

IAEA0953/02:

The three test problems included in this package were executed at the NEA DB on a DEC VAX6600 computer in 40 seconds.

7. UNUSUAL FEATURES OF THE PROGRAM - BASACF solves the same problem as STAY'SL, but on a different theoretical basis, and employs a different numerical algorithm. Compared to STAY'SL it is equipped with additional features: utilization of SAND II type spectrum and cross section libraries, two more methods for generation of covariance matrices, normalisation of the apriori flux and output of the adjusted cross sections and their covariance matrix. These advantages call for larger requirements in memory and computing time in comparison with STAY'SL. The tests do not show any difference of results between these programs.
The main program is a framework of many subroutines and can be easily tailored to a special problem (adjustment of dosimetry cross sections, special prints etc.). Especially the subroutine which provides all apriori data can be replaced by user written one in case that a different format is used for the apriori data.

8. RELATED AND AUXILIARY PROGRAMS - The program can use SAND II type libraries of spectra and cross sections generated by auxiliary programs CSTAPE and SLTAPE.
Data for STAY'SL auxiliary programs FCOV and XCOV can be used for generation of covariance matrices by the block method.

9. STATUS
IAEA0953/01: 27-MAR-1996 Obsolete
IAEA0953/02: 27-MAR-1996 Tested at NEADB

10. REFERENCES  -
- Tichy M.
  Bayesian Approach to Neutron Spectrum Adjustment,
  Nucl. Instr. & Meth. in print.
IAEA0953/02:
- Milos Tichy:
  The Program BASACF - PC Version, Description and User's Guide
  UDZ 254/88 (March 1990)

11. MACHINE REQUIREMENTS - 310 KB of the main memory. Maximum 8 and minimum 3 logical units are used (all files are sequential i.e. magnetic tapes or discs can be employed).

12. PROGRAMMING LANGUAGE(S) USED -
IAEA0953/02: FORTRAN-77

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED - OS/EC MVT 6.1 M9B; compatible with IBM 360/370 systems.

IAEA0953/02:

The tests were performed at the NEA DB on a VAX-6600 computer running under VMS and on a PC/80486 running MS-DOS.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS - The program can be used without any change on any computer with a Fortran compiler and a sufficient amount or directly addressable memory.

15. NAME AND ESTABLISHMENT OF AUTHORS -
          Milos Tichy
          SEVEN
          The Energy Efficiency Centre
          Slezska 7
          CS-120 56 Prague 2
          Czech Republic

16. MATERIAL AVAILABLE -
IAEA0953/02:
IAEA0953_02.001   Information File                                  102 records
IAEA0953_02.002   Manual in CHI-writer Format                      3929 records
IAEA0953_02.003   BASACF Control Statements for VMS                  79 records
IAEA0953_02.004   BASADAT Fortran Source                           1043 records
IAEA0953_02.005   BASAUNF Fortran Source                           1024 records
IAEA0953_02.006   TEST.CSI Cross Sections for Sample Problems        37 records
IAEA0953_02.007   TEST.FLI Flux File for Sample Problems              6 records
IAEA0953_02.008   TEST1D.DAT BASADAT S.P. 1 Input                    24 records
IAEA0953_02.009   TEST1.BDP  BASADAT S.P. 1 Output                   54 records
IAEA0953_02.010   TEST1U.DAT BASAUNF S.P. 1 Input                    14 records
IAEA0953_02.011   TEST1.BUP  BASAUNF S.P. 1 Output                  233 records
IAEA0953_02.012   TEST2D.DAT BASADAT S.P. 2 Input                    33 records
IAEA0953_02.013   TEST2.BDP  BASADAT S.P. 2 Output                   53 records
IAEA0953_02.014   TEST2U.DAT BASAUNF S.P. 2 Input                    14 records
IAEA0953_02.015   TEST2.BUP  BASAUNF S.P. 2 Output                  233 records
IAEA0953_02.016   TEST3D.DAT BASADAT S.P. 3 Input                    76 records
IAEA0953_02.017   TEST3.BDP  BASADAT S.P. 3 Output                  121 records
IAEA0953_02.018   TEST3U.DAT BASAUNF S.P. 3 Input                    14 records
IAEA0953_02.019   TEST3.BUP  BASAUNF S.P. 3 Output                  233 records
IAEA0953_02.020   Manual in ASCII Format                           1288 records

17. CATEGORIES -

- O. Experimental Data Processing

Keywords: EXPERIMENTAL DATA, NEUTRON, NEUTRON DETECTORS, NEUTRON SPECTRA

Home - About Us - Work Areas - Data Bank - Publications - Press Room - List of acronyms - Search