Relative HCP Thermoluminescence and Optical Absorption Efficiencies: The Demise of Track Structure Theory

The thermoluminescence relative efficiency, ηTST, of LiF:Mg,Ti and LiF:Mg,Cu,P following heavy charged particle irradiation is calculated using track structure theory and compared with experimental measurements. The calculations use both 60Co generated values of secondary electron dose response and values of the dose response at lower photon energies. In both materials there is poor agreement with experiment. Optical absorption relative efficiencies are also in disagreement. For the F band, ηexpt’l/ηTST = 2.0 and 2.6 for He ions and protons, respectively. The values of ηexpt’l/ηTST for the 4.0-eV band, resulted in 0.18 (protons) and <0.12 (He ions). An indication that the 4.0-eV trapping structure is either destroyed or de-populated during the heavy charged particle (HCP) slowing down. The large deviations of ηexpt’l/ηHCP from unity demonstrate that TST, which predicts HCP induced radiation effects from the exclusive action of the released secondary electrons, is woefully inadequate.

Modeling the impacts of heavy charged particles on electrical characteristics of n-MOSFET device structure

The use of microelectronic products in outer space is possible if protection is provided against special external influencing factors, including radiation effect. For digital integrated circuits manufactured using submicron CMOS processes, the greatest influence is exerted by radiation effects caused by exposure to a heavy charged particle. The use of special design tools in the development of dual-purpose microcircuits, with increased resistance to the impact of heavy charged particles, prevents single events from occurring. Thus, the use of modern software products for device and technological modeling in microelectronics when developing the element base of radiation-resistant microcircuits for space purposes will cut the time to develop new products and make it possible to modernize (improve performance) already existing device and circuitry solutions. The paper delivers the results of modeling the impacts of heavy charged particles with a magnitude of linear energy transfer equal to 1.81, 10.1, 18.8, 55.0 MeV·cm2/mg, corresponding to nitrogen ions 15N+4 with an energy E = 1,87 MeV; argon 40Ar+12 with an energy E = 372 MeV; ferrum 56Fe+15 with an energy E = 523 MeV; xenon 131Xe+35 with an energy E = 1217 MeV, on electrical characteristics of n-MOSFET device structure. The dependences of the maximum drain current IС on the motion trajectory of a heavy charged particle and the ambient temperature are shown.

THE RECENT SUCCESS OF MICRODOSIMETRY

Recent successful microdosimetric calculations of heavy charged particle efficiencies are evaluated with suggestion for future research.