Nanoscale modeling of the response of luminescent detectors for measuring different radiation qualities

SCK•CEN Mentor

Parisi Alessio, aparisi@sckcen.be, +32 (0)14 33 28 08

Expert group

Research in Dosimetric Applications

Introduction

The increasing utilization of luminescent detectors in complex radiation environments as space and hadron therapy beams requires an accurate knowledge of their efficiency for measuring a wide range of charged particles and energies. Hence, in the last decades a lot of effort has been put in assessing the relative efficiency of these detectors by means of calibrated exposures at ground based particle accelerators (Berger and Hajek, 2008, Sawakuchi et al., 2008). However, this process is time consuming and very expensive. Furthermore, due to technical limitations it is often not possible to irradiate the detectors with energies above 1 GeV/u or with less common isotopes. In addition, the efficiency determination for very low energies is biased with big uncertainties of all parameters (i.e. LET, range, absorbed dose). Nevertheless, a complete characterization of the efficiency of these detectors is needed, especially for space applications where particles with a really broad energy spectrum and exotic isotopes are present

Using the Monte Carlo code PHITS (Sato et al., 2018), a model has been recently developed to predict the relative efficiency of luminescent detectors for measuring different radiation qualities (Microdosimetric d(z) Model, Parisi et al., 2017 a, Parisi et al., 2017 b, Parisi, 2018). The model is based on microdosimetry (i.e. the study of the stochastic nature of energy deposition in microscopic targets (International Commission on Radiation Units and Measurements, 1983) and it is able to relate the microscopic changes in the pattern of energy deposition with the detector efficiency for measuring different radiation qualities.

The Microdosimetric d(z) Model has been successfully applied for describing/predicting the relative efficiency of three types of luminescent detectors, namely LiF:Mg,Ti (MTS and MTT) and LiF:Mg,Cu,P (MCP), exposed to charged particles from 1H to 132Xe ions, thermal neutrons, photons, exotic particles and antimatter.

Objective

The aim of this work is to extend the validity of the Microdosimetric d(z) Model to other detector types such as CaF2:Tm thermoluminescent detectors and Al2O3:C optically stimulated luminescent detectors.

The structure of the work is summarized hereunder.

  • Creation of a database of relative efficiency of luminescent detectors including SCK•CEN and literature data
  • Simulations of the radiation-detector interaction at a nanometric scale using the Monte Carlo code PHITS in different sensitive sizes ranging from 1 to 2000 nm.
  • Experimental determination of the dose response of the detectors by experimental irradiations at SCK•CEN and/or by using literature data
  • Application of the Microdosimetric d(z) Model for predicting the efficiency of the detector as function of the dimension of the sensitive sites
  • Identification of the optimal sensitive size dimension
  • Validation of the obtained results by an in depth comparison with experimentally determined efficiency data
  • Uncertainty assessment
  • Writing of the thesis/internship report

 

References
Berger, T. and Hajek, M., 2008. TL-efficiency—overview and experimental results over the years. Radiation Measurements, 43(2-6), pp.146-156.


Parisi, A., Van Hoey, O. and Vanhavere, F., 2017 a. Microdosimetric modeling of the relative luminescence efficiency of LiF:Mg,Ti (MTS) detectors exposed to charged particles. Radiation protection dosimetry, pp.1-4.

Parisi, A., Van Hoey, O., Mégret, P. and Vanhavere, F., 2017 b. Microdosimetric modeling of the relative luminescence efficiency of LiF:Mg,Cu,P (MCP) detectors exposed to charged particles. Radiation protection dosimetry, accepted for publication.

Parisi, A., 2018. Space and Hadron Therapy with Luminescent Detectors: Microdosimetric Modeling and Experimental Measurements. PhD Thesis, Polytech of Mons.

Sato, T., Iwamoto, Y., Hashimoto, S., Ogawa, T., Furuta, T., Abe, S.I., Kai, T., Tsai, P.E., Matsuda, N., Iwase, H. and Shigyo, N., 2018. Features of Particle and Heavy Ion Transport code System (PHITS) version 3.02. Journal of Nuclear Science and Technology, pp.1-7.

Sawakuchi, G.O., Yukihara, E.G., McKeever, S.W.S., Benton, E.R., Gaza, R., Uchihori, Y., Yasuda, N. and Kitamura, H., 2008. Relative optically stimulated luminescence and thermoluminescence efficiencies of Al 2 O 3: C dosimeters to heavy charged particles with energies relevant to space and radiotherapy dosimetry. Journal of Applied Physics, 104(12), p.124903.

 

The minimum diploma level of the candidate needs to be

Professional bachelor , Academic bachelor , Master of industrial sciences , Master of sciences , Master of sciences in engineering

The candidate needs to have a background in

Physics