Development of a motorized system for the characterization of the RQR reference x-ray beams at the KFSHRC's SSDL using an extrapolation chamber.

An extrapolation chamber of type Böhm 23392, used for the dosimetry of RQR beam qualities at the Secondary Standard Dosimetry Laboratory of King Faisal Specialist Hospital, is presented. A computer-based motorized system consisting of a stepping motor coupled to the chamber's built-in micrometer screw was designed to expedite the measurements process, giving a linear relationship between the number of motor steps and the chamber depth with a Coefficient of Determination (COD) equal to 0.9990.

A study of laser-induced blue emission with nanosecond decay of silicon nanoparticles synthesized by a chemical etching method.

Silicon nanoparticles (Si NPs), exhibiting a strong visible photoluminescence (PL), have found many applications in optoelectronics devices, biomedical tags and flash memories. Chemical etching is a well-known method for synthesizing orange-luminescent, hydride-capped silicon nanoparticles (H/Si NPs). However, a blueshift in emission wavelength occurs when reducing the particle size to exciton Bohr radius or less.