Modification Induced by Neutron Irradiation to Different Polymeric Nuclear Detectors

The development and the characterization of new reliable and inexpensive precise neutron dosimeters can present an effective alternative to the expensive dosimeters existing on the market. To do this, the correlations between various physical and chemical changes versus neutron doses must be optimized. Detectors based on polymeric materials are of great interest in different fields and widely used nowadays. Understanding the nature of polymers used in nuclear detectors is crucial to enhance the behavior of these detectors. Therefore, in this study, the induced modifications in the wettability and etching properties of Hostaphan and Makrofol solid state nuclear track detectors irradiated by different fluences of thermal neutrons were investigated. The wetting property is studied by contact angle method. The resulting decrease in the contact angle was attributed to the change in surface morphology, roughness, structure, hardness, chemistry and free energy. The neutrons induced changes in surface chemistry were studied using Fourier transform infrared spectroscopy, which shows an increase in surface polarity due to the formation of polar groups over the surface of both polymeric detectors. Surface morphology and roughness of both polymers were recorded and shows a drastic changes after irradiation. Additionally, surface structure and hardness of pristine and irradiated polymers were discussed and correlated to the enhancement in surface wettability as well. Surface free energy of both polymeric materials are calculated through three different methods. Surface free energy values were found to increase after neutrons irradiation. Also, the differences in the calculated values of surface free energy by the three applied techniques were attributed to the differences in the intermolecular interactions in the liquid/polymer system. Finally, the etching characteristics of the studied detectors were discussed. In conclusion, thermal neutrons show efficiency in improving surface wettability and etching properties of Hostaphan and Makrofol in a controlled way. This happen through inducing several physical and chemical changes inside the material which could be optimized in accordance which neutron fluence to calibrate the detectors in a controlled way