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Manuscript Title: Program system for analysing positron lifetime spectra and angular correlation curves.
Authors: P. Kirkegaard, M. Eldrup, O.E. Mogensen, N.J. Pedersen
Program title: PATFIT
Catalogue identifier: AANN_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 23(1981)307
Programming language: Fortran.
Computer: BURROUGHS 6700.
Operating system: B6700 MCP MARK III.0.1, CDC NOS.VER.1.4-509/508-A.
RAM: 70K words
Word size: 48
Peripherals: disc.
Keywords: Solid state physics, Atomic physics, Positron annihilation, Lifetime, Angular correlation Curve, Least squares, Fitting, Convolution, Resolution function, Minimization, Marquardt, Constraints, Correlation matrix, Experiment.
Classification: 2.3, 7.4.

Other versions:
Cat Id Title Reference
AAGK_v1_0 POSITRONFIT CPC 3(1972)240
AAGZ_v1_0 DBLCON CPC 13(1977)371
ACKX_v1_0 PFPOSFIT CPC 30(1983)359

Nature of problem:
In the field of positron annihilation research two of the experimental methods used are positron lifetime and angular correlation measurements. In both cases a measured spectrum normally consists of a sum of several components. The experimenter wants to extract from the spectra characteristic parameters for each component.

Solution method:
A measured spectrum is fitted with a mathematical model by a constrained semilinear least-squares technique. This results in estimates of the model function parameters.

There are certain limitations on the number of fitting parameters and data points, which are listed in the context of the four programs.

Running time:
(CYBER 173 CPU-seconds for the test cases) POSITRONFIT: 8.4 s, RESOLUTION: 9.8 s, PAACFIT: 3.2 s, PARAFIT 3.1 s.