• D Kanjilal

Articles written in Pramana – Journal of Physics

• Modifications induced in the polycarbonate Makrofol KG polymer by Li (50 MeV) ion irradiation

Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 𝜇m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion ($+3$ charge state). Build-in modifications due to irradiation were studied using FTIR and XRD characterizations. Considerable changes have been observed in the polymer while varying the fluence from 1E11 ion/cm2 to 1E13 ion/cm2 Li ions. AFM images of the surface modifications caused by ion irradiation on the polymer are also presented.

• Electric field distribution and simulation of avalanche formation due to the passage of heavy ions in a parallel grid avalanche counter

Electric field distributions and their role in the formation of avalanche due to the passage of heavy ions in parallel grid avalanche type wire chamber detectors are evaluated using a Monte Carlo simulation. The relative merits and demerits of parallel and crossed wire grid configurations are studied. It is found that the crossed grid geometry has marginally higher gain at larger electric fields close to the avalanche region. The spatial uniformity of response in the two wire grid configurations is also compared.

• Opto-chemical response of Makrofol-KG to swift heavy ion irradiation

In the present study, the effects of swift heavy ion beam irradiation on the structural, chemical and optical properties of Makrofol solid-state nuclear track detector (SSNTD) were investigated. Makrofol-KG ﬁlms of 40 𝜇m thickness were irradiated with oxygen beam ($O^{8+}$) with ﬂuences ranging between 1010 ion/cm2 and 1012 ion/cm2. Structural, chemical and optical properties were investigated using X-ray diffraction, FTIR spectroscopy and UV–visible spectroscopy methods. It is observed that the direct and indirect band gaps of Makrofol-KG decrease after the irradiation. The XRD study shows that the crystalline size in the ﬁlms decreases at higher ﬂuences. The intensity plots of FTIR measurements indicate the degradation of Makrofol at higher ﬂuences. Roughness of the surface increases at higher ﬂuence.

• # Pramana – Journal of Physics

Current Issue
Volume 93 | Issue 5
November 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019