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In the present paper, the surface modification of low-density polyethylene (LDPE) polymer is done by plasma-etching to tune its surface structure, wettability and optical behavior to make it useful for technical applications. For this purpose, two gasses (N[Formula: see text] and (O[Formula: see text] are used as the discharge precursors in a home-built plasma reactor. The plasma-treated LDPE surface etch-rate (control other surface properties) is high at the beginning and slows down as the treatment time increases due to surface restructuring. The etched surfaces are analyzed by scanning electron microscopy (SEM), which indicate greater surface changes due to O2 plasma compared to that of N2. Also, the surface hardness is slightly low at the first treatment time and increases rapidly at higher exposure durations. Besides, the friction coefficient is significantly changed by plasma treatment, suggesting the formation of cohesive surface skin. The obtained X-ray diffraction (XRD) patterns show that the plasma-treated LDPE samples suffer disordering and structural changes which increase with raising the treatment duration. Surface restructuring is attributed to the combined effects of active species (from plasma) bombardments and surface oxidation. Also, the surface chemistry changes are evaluated using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy which reveals chain scission after N2 plasma treatment. Whereas, the O2 plasma-treated samples suffer surface oxidation and formation of polar groups which offer some surface oxidation coatings. Furthermore, the surface wettability has been determined by the sessile drop method and shows enhancement upon plasma treatment due to the combined influence of surface chemistry and morphology. Also, the surface free energy (SFE) and adhesion are found to increase with the plasma exposure time due to surface activation. The optical behavior of LDPE is studied using ultraviolet–visible (UV–Vis) spectrophotometer which indicates that the optical bandgap performance depends on the amorphous or crystalline nature of the polymer. Also, the conjugated carbon atoms were examined and correlated to the reduced bandgap. In conclusion, the studied home-built glow discharge plasma reactor could be utilized efficiently to tune polymer surface properties to be used in high technology applications.

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In the present work, an investigation has been made for the ext raction characteristics and beam diagnosis for a Pierce-type electron gun with spherical anode to acquire an electron beam suitable for different applications. The acceleration voltage increases the electron beam currents up to 250 mA at Accelerat ion voltage 75kV and decreases the beam perveance, beam waist and beam emittance. The min imu m beam radius could be found at the min imu m beam perveance and maximu m convergence angle. Also the increase of the accelerating voltage affects the increase of the beam fluence rate up to 1.3 x 10 18 e/min.cm 2 , due to the increase of the extracted current. Tracing the electron beam profile by X-Y p robe scanner along the beam line at two different places reveals that the spherical anode affects the beam to be convergent. The electron beam could be suited for the two suggested experiments in our lab, p lasma acceleration and surface modifications of poly mers.