Study of the optical properties and the carbonaceous clusters in DAM-ADC solid state nuclear track detectors

The impact of the broad range of gamma doses on follow-up fission fragment track parameters in CR-39 radiation detector

In this study, the effect of high γ-doses on the track parameters, structure as well as optical properties of pristine and γ-irradiation CR-39 nuclear track detector (NTD) were investigated. CR-39 detectors were exposed to γ-doses from 50 up to 500 kGy and then irradiated by fission ions (F.F) of fluence from 252CF source. The track diameter (D), bulk etch rate (VB), etch induction time (EIT), cut-off or saturated time (tcut-off) for saturated diameters and projected track length (Lo) of normally and inclined incident fission tracks were estimated for different removal layers (h). A linear relationship between D and γ-doses (Dγ) up to 500 k Gy was obtained. The VB for pristine and for γ-irradiated CR-39 was determined. A linear behaviour of VB was obtained up to 300 kGy. Etch induction time (EIT) and saturated time (tcut-off) of pristine and γ-irradiated detectors for normal and inclined fission ions tracks were evaluated respectively up to 500 kGy. Each EIT and tcut-off decreased exponentially fast with increasing γ-doses but the inclined incidence appeared earlier than normal case. Pristine and γ-irradiated CR-39 detectors were examined using FTIR and UV-Vis spectrophotometer. From this study, a linear relation of band gap energies (Egap) as a function of γ-doses, Dγ, was obtained. The value of (Egap) decreased when increasing γ-doses for direct and indirect transitions, respectively. In addition, a systematic increase of Urbach energy (EU) was recorded together with the Dγ increase. Moreover, a linear behavior of the refractive index (n) along with γ-irradiated CR-39 plastic detector was observed via direct and indirect methods.

The Annealing Impact on Properties of CN- 85 Polymer NTD

Samples of cellulose nitrate polymer (CN-85) were annealed at 100 °C, 120 °C, and 140 °C for 15 min before and after irradiation with alpha particles emitted from a²⁴¹Am source. Irradiation was performed at room temperature for 5 min. The changes in the optical and structural properties of CN-85 NTD, due to annealing and irradiation, were studied by using ultraviolet-visible spectroscopy (UV-VIS), and Fourier transform infrared spectroscopy (FTIR). Direct and indirect energy gap values, the number of carbon atoms, carbon clusters, and Urbach's energy values were determined. The UV-VIS analysis showed a shift in the absorption edge of the CN-85 polymer toward long wavelengths. The FTIR results revealed the changes in some bonds and the structural decomposition of CN-85 due to irradiation. The direct band gap energy was slightly decreased from 4.13 eV to 4.09 eV when the pristine samples were heated to 140 °C and irradiated. The indirect band gap energy was decreased from 3.9 eV to 3.8 eV under the same conditions. The Urbach's energy values showed a fluctuating rise with increasing annealing temperature for the irradiated and heated samples. When the pristine samples irradiated and heated, the band gap energy is reduced from 4.13 eV to 4.06 eV and from 3.90 eV to 3.84 eV for the direct and indirect transition, respectively. In conclusion, this technique showed promising benefits for a wide range of applications such as optoelectronics and microelectronic devices.