Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] aann_v1_0.gz(68 Kbytes)
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
AAGX_v1_0 POSITRONFIT EXTENDED CPC 7(1974)401
AAGZ_v1_0 DBLCON CPC 13(1977)371
AAHI_v1_0 INTERACTIVE POSITRONFIT CPC 15(1978)97
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.

Restrictions:
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.