A newly developed molecular beam method allowed the differential elastic and double-differential inelastic electron scattering cross sections of triethylamine to be measured absolutely for the first time. These data provide the basis for a Monte Carlo simulation model with the aid of which the track structures measured with the particle track chamber OPAC can be analyzed.


The experimental determination of the differential elastic and double-differential inelastic-electron scattering cross sections of triethylamine (TEA) is of interest for the investigation of radiation damages in nanometric areas of living organisms, as the chemical components and bonding types of TEA frequently occur in biomolecular systems such as the DNA. Here, the cross sections for electrons are of special importance, as electrons are generated as secondary particles in matter by all beam types. Moreover, due to its favourable optical properties, TEA is used as a counting gas in optical particle track detectors such as the OPAC chamber, and knowledge of the electron scattering cross sections of TEA is indispensable for a more exact analysis of the ionization density of high-energy ions which can be measured with this chamber.

The differential elastic cross sections and the double-differential inelastic scattering cross sections were measured with the aid of a newly developed molecular beam measuring method, which allows the electron cross sections to be determined by experiment without knowing the interacting volume between electron beam and molecular beam. This method has successfully been tested on inert gas atoms.

The cross sections were measured for electrons with primary energies from 20 eV to 1 keV in the scattering angle range between 35° and 135°. The energy of the secondary electrons extended from 4 eV up to the primary electron energy. Together with the total electron scattering cross sections which were also measured within the scope of the experiment, these data sets allow the track structures of electrons in nanometric ranges to be calculated in detail. As an example of the results, the figure shows the double-differential inelastic scattering cross sections of TEA for electrons with a primary energy of 100 eV as a function of the energy and the polar angle of the emitted electrons.

Figure: Double-differential inelastic cross section d²σ/dEdΩ of TEA for 100 eV electrons as a function of the energy E and the polar angle θ of the electrons emitted into the solid angle dΩ.

W. Y. Baek, Dep. 6.6, WG 6.61, E-Mail: WoonYong.Beak@ptb.de pdf (362 kB)

---

© Physikalisch-Technische Bundesanstalt Page created: 2006-04-10, last update: 2006-07-26, Webmaster Abt. 6