An upgraded track structure model: experimental validation

Area of Science:

• * Physics
• * Radiation Science
• * Nanotechnology

Background:

• * The track nanodosemeter at Legnaro National Laboratories (LNL) enables direct study of particle track characteristics.
• * It measures ionization-cluster-size distributions in nanometer-sized target volumes.
• * Accurate simulation of these distributions is crucial for understanding radiation interactions.

Purpose of the Study:

• * To enhance the quantitative agreement between experimental measurements and Monte Carlo simulations of particle track structure.
• * To refine the cross-section data used in the Monte Carlo model, particularly for secondary electron energy.
• * To validate the HKS and Rudd models for impact ionization cross-sections.

Main Methods:

• * Development and application of a dedicated Monte Carlo code for simulating ionization cluster sizes.
• * Direct measurement of ionization-cluster-size distributions using the track nanodosemeter.
• * Re-evaluation of cross-section data based on extensive track structure measurements.

Main Results:

• * The Monte Carlo code successfully reproduces the general shape of measured cluster-size distributions.
• * Quantitative differences between simulated and measured data were reduced through cross-section refinement.
• * Specific focus was placed on impact ionization cross-sections for secondary electrons.

Conclusions:

• * The study demonstrates the effectiveness of the track nanodosemeter for particle track investigation.
• * Revisiting cross-section validity significantly improves simulation accuracy.
• * The findings contribute to a more precise understanding of radiation interactions at the nanoscale.