Physical Science Laboratory

Dr. Buddharam Shah



Dr. Buddha Ram Shah
Tel : +97715550828
Email: physicalscience@nast.gov.np



Physical Science Unit

  • Environmental Radioactivity
  • Personnel Dosimetry
  • Household Radon Survey
  • Radiation from Cell Phone Towers
  • Development of Thin films & Nano-particles

Environmental Radioactivity: A national network of radioactivity is established for measuring terrestrial radioactivity in environmental samples and in the air. The assessment of radioactivity due to Uranium and Thorium series, Potassium-40 along with total radioactivity will provide the baseline information of our radiation environment. Thus obtained data on environmental radioactivity will be represented in thematic useful for health, environment and education services.

NaI(Tl) Detector Coupled with MCA                  Roentzen Gamma Dosimeter                                        NaI(Tl) Detector Coupled with MCA                                         Roentzen Gamma Dosimeter

Personnel Dosimetry: Thermoluminescent Dosimeters (TLD) are used to monitor radiation doses absorbed by personnel (especially technician, radiographer, radio-therapist, medical physicist, etc.). Under the TLD based personnel-monitoring system, the radiation workers wear the dosimeter for a specific period and the radiation exposure is estimated on the basis of TL dosimetric reading on the TLD Badge Reader. The purpose is to establish radiation safety culture by providing TLD service on periodic and regular basis to all persons involved in radiation work in the country. 

TLD Badge Reader
TLD Badge Reader   

Household Radon Survey: Radon and its radioactive daughters present in the environment results into the largest contribution to the average effective natural radiation dose received by human beings. Radon has been identified as the second leading cause of lung cancer after tobacco smoking. The study of radon and its progeny exposure in dwellings is important as it can result in to a significant inhalation risk to population particularly to those living in homes. A Solid State Nuclear Track Detector (SSNTD) technique has been employed to study radon exposure in the dwellings of Kathmandu Valley. 

Kodalpha Radon Dosimeter
Kodalpha Radon Dosimeter

Radiation from Cell Phone Towers: Cell phone technology has revolutionized the telecommunication scenario in Nepal. Due to its various advantages, cell phone technology has grown exponentially in the last decade and similarly the numbers of cell phones and cell towers are increasing without giving due respect to its disadvantages. All over the world, people have been debating about associated health risk due to radiation from cell phone and cell tower. Assessment of power density due to RF (radio-frequency) exposure from the cell phone towers in the Kathmandu valley is in the process.

RF Field Strength Meter (TM-196)

RF Field Strength Meter (TM-196)

Development of Thin films & Nano-particles: Our research stresses on the investigation of advanced oxide materials – both thin film and nanostructures – in pursuit of three major research thrusts: 1) Optical and electrical properties of materials, 2) Functional Materials and Devices, and 3) Metal oxides for Solar Energy Conversion. The foundation of the research is based on the growth of metal oxide thin films and nanostructures via a wet chemical route.  

Optical and Electrical Properties of Materials: This area of research aims to elucidate realm of solid state materials science – the physics and control of doping effects in materials. Our comprehensive approach includes aspects of materials design, synthesis and advanced characterization development and utilization. 

Spin coater  UV-Vis Spectophotometer
Spin coater                        UV-Vis Spectophotometer

Functional Materials and Devices:  Driven by recent advances in the production of high quality thin films of metal oxide materials and nanoparticles, immense attention has been given to recognize their possible applications in photo-catalyst, gas sensors, self-cleaning material etc. 

D2 phaser Bruker XRD
D2 phaser Bruker XRD

Metal Oxides for Solar Energy Applications: Motivated by the escalating need for alternative energy, we are studying the creation of oxide-based photovoltaic devices.  An effort has been made on applying fundamental understanding of semiconducting properties (i.e. band gap, carrier mobility and absorption) in these materials.


Team Members


1. Dr. Buddha Ram Shah

2. Dr. Deependra Das Mulmi

3. Mr. Bipin Rijal