Dosimetry in mixed neutron-gamma fields with a Timepix detector. (December 2018)

• Record Type: Journal Article
• Authors: Rubovič, Peter; Ekendahl, Daniela; Vykydal, Zdeněk; Hůlka, Jiří; Bergmann, Benedikt; Pospíšil, Stanislav; Štekl, Ivan
• Is Part Of: Radiation measurements. Volume 119(2018:Dec.)
• Page Start: 22
• Page End: 26
• Publication Date: 2018-12
• Subjects: Timepix -- Gamma -- Neutron -- Dosimetry -- Fission; Nuclear emulsions -- Periodicals; Particle tracks (Nuclear physics) -- Periodicals; Thermoluminescence -- Periodicals; Cosmic rays -- Periodicals; Radiation -- Measurement -- Periodicals; Radiometry -- Periodicals; Radiation Monitoring -- Periodicals; Émulsions nucléaires -- Périodiques; Particules (Physique nucléaire) -- Traces -- Périodiques; Thermoluminescence -- Périodiques; Rayonnement cosmique -- Périodiques; Radiométrie -- Périodiques; 539.77
• DOI: 10.1016/j.radmeas.2018.08.018
• Languages: English
• ISSNs: 1350-4487

Abstract

Abstract: We used the hybrid semiconductor pixel detector Timepix as an area dosimeter in mixed neutron-gamma fields. The surface of the detector was covered with several converters based on 6 Li, polyethylene, Th and enriched U. We used three different neutron sources for calibration of the device – thermal neutrons from graphite pile, 241 Am-Be and 252 Cf. The desired neutron component of dosimetry and operational quantities can be determined by counting events under the converters. The segmentation of the Timepix detector and its capability to measure energy deposition of each interacting quantum of ionizing radiation allows a separation of neutron events from X-ray/gamma or electron interaction. Thus, the device can also be used for simultaneous X-ray and gamma dosimetry, where it is in some aspects superior to most of the commercial devices, given its detection threshold of 3–5 keV. Highlights: Concept of using Timepix detector as a dosemeter in unknown mixed neutron-gamma fields. Several converters based on 6LiF, PE and fission radiators are used. Both neutron and gamma component of desired dosimetry or operational quantities are determined simultaneously. Efficient discrimination of fission fragments and alpha particles is presented.