Speaker
Description
One of the primary Ion Beam Analysis (IBA) techniques employed for the determination of sample composition and depth profile analysis is Time of Flight – Elastic Recoil Detection Analysis (ToF – ERDA). The silicon-based detectors (SSB) are used to conventionally record the energy of the recoiled particles that are analyzed following the implementation of the specific technique. The quality of the measurement can be considerably impacted by the SSB detector's low depth and mass resolution capabilities [1][2]. In the specific technique, the detection of heavy particles requires high energy, depth, and mass resolution, as well as the ability to withstand radiation damage. Consequently, it is essential to replace the silicon energy detector with a Gas Ionisation Detector (GID) in the ToF – ERDA spectrometer at N.C.S.R. "Demokritos."
The new GID is a custom-built in-house assembly. The technical attributes of the detector are in accordance with the requirements of the ToF-ERDA technique. The anode and cathode electrodes are two parallel copper plates, separated by a Frisch grid to shield the anode from the active volume of the detector. The electromagnetic field between the various components was estimated through the completion of related simulations. The properties and quality of the detector's performance were determined using dedicated measurements with a variety of configurations and settings. The outcome of employing various gas types under varying pressure conditions was also evaluated. The associated findings of the initial evaluation exams will be presented and discussed.
[1] Z. Siketić, N. Skukan, and I. Bogdanović Radović, “A gas ionisation detector in the axial (Bragg) geometry used for the time-of-flight elastic recoil detection analysis,” Rev. Sci. Instrum., vol. 86, no. 8, Aug. 2015, doi: 10.1063/1.4927605/357185.
[2] J. Julin, M. Laitinen, and T. Sajavaara, “Time-of-flight ERD with a 200 mm2 Si3N4 window gas ionization chamber energy detector,” Nucl. Instruments Methods Phys. Res. Sect. B Beam Interact. with Mater. Atoms, vol. 332, pp. 271–274, Aug. 2014, doi: 10.1016/J.NIMB.2014.02.076.