Manveer Singh

A new high sensitivity Na2LiPO4:Eu OSL phosphor

A new high sensitivity Na2LiPO4:Eu optically stimulated luminescence dosimeter (OSLD) material was prepared by a simple solid-state diffusion method. The formation of the material was confirmed by comparing the experimental data with that available in the literature (JCPDF # 80-2110). The dosimetric properties of the phosphor material using a continuous wave-optically stimulated luminescence (CW-OSL) technique were studied. The material was studied for different concentrations of the impurity and also for different heating treatments. The material doped with 1.0 mol% and annealed at 873 K was found to be the most sensitive. The phosphor was found to have all the good dosimetric characteristics, such as tissue equivalence (low-Z, Zeff ∼ 10.8), high sensitivity (∼3 times less than the commercially available Al2O3:C, Landauer Inc., USA and BeO, Thermalox® 995, Materion Inc., USA), low fading (∼6.2% in 40 days), wide range of dose response (0.1–1.0 kGy), excellent reusability, easy optical bleaching (annealing) for its reuse, etc., which makes the material useful for dosimetry of high-energy radiations using OSL. The advantages of our OSLD phosphor are the easily available and inexpensive ingredients and a very simple method of preparation that makes it cost effective as compared to the commercially available OSLD phosphors. Also, it is easy to handle, unlike the Thermalox® 995 (BeO) dosimeters which are very toxic, and require a special method of preparation and handling.

Characterization of Nano‐Crystalline Diamond like Carbon (DLC) Films with Substrate Temperature Using Dense Plasma Focusing Method

Nano‐crystalline Diamond like Carbon (DLC) film has been grown by Dense Plasma Focusing Method (DPF) using pure graphite Plasma, on different substrate (glass/silica) at different substrate temperature. The films were grown at substrate temperature 100° C, 150° C & 300° C by the high dense plasma of energy 1.3 k Joule on glass and silica. Raman spectra confirmed that sp3 content is grown in the films under various conditions. The Raman spectra of these films show a broad asymmetric peak which narrow with sp2 decreasing contents. We believe that our data presented here may be used as reference of DLC characterization.