last modified: 09-MAY-1989 | catalog | categories | new | search |

IAEA0942 TRAX.

TRAX, Resolution Matrix of Slow Neutron Spectrometers

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1. NAME OR DESIGNATION OF PROGRAM:  TRAX.
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2. COMPUTERS
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Program name Package id Status Status date
TRAX IAEA0942/01 Tested 09-MAY-1989

Machines used:

Package ID Orig. computer Test computer
IAEA0942/01 CDC CYBER 720 CDC CYBER 830
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3. DESCRIPTION OF PROGRAM OR FUNCTION

TRAX computes the resolution matrix and characteristic line-widths and intensities for three-axis slow-neutron spectrometers with flat or curved, mosaic or perfect crystals, with or without Soller collimators or limiting diaphragms, neutron guide in the incoming beam allowed for. The optimization of  the spectrometer configuration from the point of view of intensity-  resolution compromise can be performed analytically or numerically,  depending on the option specified in the input data. In the analytical optimization the monochromator and analyzer radii of curvature are computed together with either the sample inclination angle, or monochromator-sample distance, or sample- analyzer distance. For numerical optimization there are 16 possible variables: monochromator and analyzer radii of curvature, cutting angles mosaic spreads and thicknesses; sample inclination angle and  thickness; distance monochromator-sample or sample-analyzer; and four Soller collimators angular divergences.
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4. METHOD OF SOLUTION

The matrix computational technique is used. A library of data on crystal monochromators is built into the program. The analytical optimization is computed through formulae valid for perfect curved thin crystals. The numerical optimization is performed by searching iteratively for the minimum of an optimization parameter with the aid of the IMSL library subroutine ZXMIN for minimizing functions of many variables.
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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:
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6. TYPICAL RUNNING TIME

Less than 1 CPU second PER CASE on the CDC-CYBER 170-720 per case with no optimization or with analytical optimization only. For numerical optimization the running time increases rapidly with the number of variables and depends on the values of the variables strat. For three variables it is less than 1 minute and  for 6 variables it is less than 10 minutes CPU.
IAEA0942/01
The test case included in this package has been run at  NEA-DB on a CDC CYBER 830 computer in 1.4 seconds of CPU time.
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7. UNUSUAL FEATURES OF THE PROGRAM:
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8. RELATED AND AUXILIARY PROGRAMS:
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9. STATUS
Package ID Status date Status
IAEA0942/01 09-MAY-1989 Tested at NEADB
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10. REFERENCES

- M. Popovici
  On the Resolution of Slow-Neutron Spectrometers. IV. The
  Triple-Axis Spectrometer Resolution Function, Spatial Effects
  Included.
  Acta Cryst (1975) A31,507-513.
IAEA0942/01, included references:
- M. Popovici, A.D. Stoica and I. Ionita:
  Optics of Curved-Crystal Neutron Spectrometers,
  I. Three-Axis Spectrometers.
- Description of IMSL Subroutine ZXMIN (June 1980)
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11. MACHINE REQUIREMENTS:  Main storage 18 Kwords (60 bits) on the CDC CYBER 170.
IAEA0942/01
62,000 (octal) words are required to run the test case  on a CDC CYBER 830.
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12. PROGRAMMING LANGUAGE(S) USED
Package ID Computer language
IAEA0942/01 FORTRAN-IV
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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  NOS-1 Operating system on the 170.
IAEA0942/01
NOS2.5.1 (CDC CYBER 830).
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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:
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15. NAME AND ESTABLISHMENT OF AUTHORS

          M. Popovici, A.D. Stoica and I. Ionita
          Institute for Nuclear Power Reactors
          Pitesti, POB 78, Romania
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16. MATERIAL AVAILABLE
IAEA0942/01
File name File description Records
IAEA0942_01.001 Information file 48
IAEA0942_01.002 TRAX how to use 319
IAEA0942_01.003 JCL and control information 9
IAEA0942_01.004 TRAX source program 2680
IAEA0942_01.005 Sample problem input 29
IAEA0942_01.006 Sample problem output 493
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17. CATEGORIES
  • O. Experimental Data Processing

Keywords: covariance matrices, resolution, scattering, spectrometers, thermal neutrons.