Communication: Electron ionization of DNA bases

Area of Science:

• Atomic and Molecular Physics
• Radiation Chemistry
• Biophysics

Background:

• Accurate electron ionization cross section data for DNA bases are essential for modeling radiation damage to genetic material.
• Existing experimental data are scarce and often unreliable, leading to discrepancies with theoretical models.

Purpose of the Study:

• To measure absolute partial and total electron ionization cross sections for DNA bases for the first time.
• To provide reliable experimental data for use in radiation damage modeling.
• To resolve existing discrepancies between theoretical and experimental results.

Main Methods:

• Utilized the relative flow technique to measure absolute partial electron ionization cross sections up to 500 eV for DNA bases.
• Summed partial cross sections to determine total ion cross sections for all four DNA bases.
• Compared experimental results with existing theoretical calculations and previous measurements.

Main Results:

• Presented a complete set of absolute partial electron ionization cross sections for DNA bases.
• Obtained reliable total ion cross sections for adenine, guanine, cytosine, and thymine.
• Resolved discrepancies between theoretical predictions and experimental findings in electron ionization cross sections.

Conclusions:

• The study provides the first reliable experimental dataset for electron ionization cross sections of DNA bases.
• These findings are critical for accurate modeling of radiation-induced DNA damage.
• Fragmentation analysis of adenine offers insights into its potential extraterrestrial formation.