for Wear Measurement
TLA is a technique to determine material losses from the investigated surfaces caused by friction forces, chemical or physical erosion or corrosion processes. The technique provides effective and precise on-line remote monitoring methods of wear, corrosion and erosion processes of critical parts in machines under real operating conditions. This work is a collection of evaluated cross sections for 55 selected charged particle induced nuclear reactions on 32 elements suitable for TLA applications .
The activity depth profile depends on the bombarding energy, the cross section of the nuclear reaction, the stopping power of the matrix material and the irradiation angle. The presented values were calculated for standard parameters which are listed for each reaction and are presented in figures for two reference times, at the end of bombardment (EOB) and after one week of cooling time to allow decay of other radioisotopes produced in side reactions simultaneously. Tabulated fitted cross section data and corresponding figures are given for each reaction together with references.
Beside the evaluated cross section data here we give help for planning the irradiation by giving optimal irradiation parameters for selected materials and nuclear reactions for two generally used irradiation conditions.
Irradiation Type 1: The selected bombarding energy is just above the energy for which the excitation function has a local maximum. The depth profile of the produced activity can be approximated as constant in the surface layer with thickness of about 10 to 50 microns in depth (production of constant activity layer).
Irradiation Type 2: The selected bombarding energy is below the maximal energy point of the excitation function. The produced activity depth profile can be approximated by a linear function in the surface layer with depth of about 10 to 100 microns (production of linear activity layer).
For TLA applications a calculation tool TLA2017 was developed to help planning irradiations and determining wear of friction surfaces from the measured activities. It requires Microsoft Excel XP or higher versions.
TLA2017 can be downloaded in compressed form here (RAR, 2.8 MB).
Help on use of the calculation tool TLA2017 is given (PDF, 119 kB).
Short description of TLA2017 in given in IAEA-NDS-xxx (PDF, xxx kB).
Comprehensive description of TLA method can be found in IAEA-TECDOC-924 (PDF, 7.3 MB).
Definitions of the quantities given - production yields, cross sections, stopping power - can be found here (PDF, 15 kB).
This work is to replace the calculation package: TLAPrfl, IAEA-NDS-192 (PDF, 15 kB).
Developed in 2010, January by S. Takacs, and updated by F. Ditrói in 2017 Atomki, Debrecen, Hungary.