Dr. Arvind Sabharwal - Academia.edu (original) (raw)
Uploads
Papers by Dr. Arvind Sabharwal
Radiation Effects and Defects in Solids
Radiation Effects and Defects in Solids, 2017
Journal of Nuclear Physics, Material Sciences, Radiation and Applications, 2014
The present studies aimed to investigate the effects of energy dependence of parameters character... more The present studies aimed to investigate the effects of energy dependence of parameters characterizing multiply backscattering of gamma photons. The numbers of multiply backscattered events are found to be increasing with thickness of copper target, and saturate for a particular thickness known as saturation thickness. The saturation thickness is found to be decreasing with increase in incident gamma photon energy, and also is not altered by the variation in collimator opening. The number, energy and dose albedos, characterizing the reflection probability of a material, are also evaluated. For each of the incident gamma photon energy, the number and energy albedos show an increase with increasing target thickness, and finally saturate. Monte Carlo calculations support the results of present experimental work.
Indian journal of pediatrics, 2005
We report a case of congenital tuberculosis diagnosed by liver biopsy in a 8-week-old infant pres... more We report a case of congenital tuberculosis diagnosed by liver biopsy in a 8-week-old infant presented with acute abdomen. Liver biopsy showed multiple lymphoepitheloid cell granulomas with Langhans' giant cells and central necrosis. The culture of caseous material from the liver showed Mycobacterium tuberculosis . Antituberculous treatment was started. Endometrial biopsy in the asymptomatic mother confirmed the source of infection.
Indian Journal of Physics, 2009
Page 1. Indian J. Phys. 83(8) 1141-1146 (2009) © 2009 IACS *Corresponding Author Experimental eva... more Page 1. Indian J. Phys. 83(8) 1141-1146 (2009) © 2009 IACS *Corresponding Author Experimental evaluation of multiple Compton backscattering of gamma rays in copper Arvind D Sabharwal*, Manpreet Singh, Bhajan Singh ...
EPJ Web of Conferences, 2012
Radioactivity, natural and man-made, is omnipresent in the earth's crust in different amounts. Na... more Radioactivity, natural and man-made, is omnipresent in the earth's crust in different amounts. Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. 226 Ra, 232 Th and 40 K analysis has been carried out in soil samples collected from some areas of Punjab, India using gamma-ray spectrometry. The technique of gamma ray spectrometry was applied using high purity germanium gamma-ray detector and a PC based MCA. Radium equivalent activities are calculated for the analyzed samples to assess radiation hazards arising due to the use of these soil samples in construction of dwellings. The measured activity in the soil ranges from 23.17 to 57.87 Bq kg −1 , 59.03 to 160.40 Bq kg −1 and 228.06 to 501.03 Bq kg −1 for 226 Ra, 232 Th and 40 K with mean values of 37.93, 84.47 and 351.17 Bq kg −1 respectively. It has been observed that on the average the outdoor terrestrial gamma air absorbed dose rate is about 84.65 nGy h −1 .
Radiation Measurements, 2009
The present studies aimed to investigate the effects of detector collimation and target thickness... more The present studies aimed to investigate the effects of detector collimation and target thickness on multiply backscattered gamma photons. The numbers of multiply backscattered events, having energy the same as in singly scattered distribution, are found to be increasing with target thickness, and saturate for a particular thickness known as saturation thickness. The saturation thickness is not altered by the
Radiation Effects and Defects in Solids, 2011
ABSTRACT The backscattered peak and albedos are important for the estimation of exposure distribu... more ABSTRACT The backscattered peak and albedos are important for the estimation of exposure distribution and for better understanding the phenomenon of the backscattering of gamma photons. To characterize the backscattering probability of gamma photons interacting with different atomic numbers (Z), number (A N), energy (A E) and dose (A D) albedos are experimentally evaluated. The response function converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. For each of the incident gamma photon energies, the number and energy albedos show an increase with the increasing target thickness, and finally saturate. The energy albedos are found to be decreasing with the increase in the atomic number of the target material and incident gamma photon energy. The dose albedos do not differ significantly from the energy albedos for the chosen incident gamma photon energies.
Physica Scripta, 2011
Page 1. Multiple backscattering on monoelemental materials and albedo factors of 279, 320, 511 an... more Page 1. Multiple backscattering on monoelemental materials and albedo factors of 279, 320, 511 and 662 keV gamma photons This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 Phys. Scr. 83 025303 ...
Journal of Physics: Conference Series, 2011
Page 1. Investigations of energy dependence of saturation thickness of multiply backscattered gam... more Page 1. Investigations of energy dependence of saturation thickness of multiply backscattered gamma photons in elements and alloys - an inverse matrix approach This article has been downloaded from IOPscience. Please scroll down to see the full text article. ...
Isotopes in environmental and health studies, 2011
Radon concentration levels in water and soil gas from 36 locations pertaining to some areas of Ma... more Radon concentration levels in water and soil gas from 36 locations pertaining to some areas of Malwa region of Punjab have been measured on an in situ basis using a continuous active radon detector (AlphaGuard, Model - PQ 2000 PRO, Genitron instruments, Germany). Exhalation rate measurements have also been carried out at these places, using a closed-circuit technique. The radon concentrations in soil and water varied from 1.9 to 16.4 kBq m(-3) and 5.01 to 11.6 kBq m(-3), respectively. The exhalation rate (E (Rn)) ranged between 7.48 and 35.88 mBq m(-2) s(-1) with an average value of 18.17 mBq m(-2) s(-1). Annual dose rates have been calculated for water radon concentrations. The minimum to maximum values of dose rates were found to be 13.42-31.08 μSv y(-1). The recorded values of radon concentration in water are within the safe limit of 11 Bq l(-1) recommended by the US Environment Protection Agency [National Research Council, Risk Assessment of Radon in Drinking Water (Academy Pres...
Radiation protection dosimetry, 2012
LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for est... more LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for estimating radon ((222)Rn) and thoron ((220)Rn) concentrations in dwellings of south-western Punjab, India. The present study region has shown pronounced cases of cancer incidents in the public [Thakur, Rao, Rajwanshi, Parwana and Kumar (Epidemiological study of high cancer among rural agricultural community of Punjab in Northern India. Int J Environ Res Public Health 2008; 5(5):399-407) and Kumar et al. (Risk assessment for natural uranium in subsurface water of Punjab state, India. Hum Ecol Risk Assess 2011;17:381-93)]. Radon being a carcinogen has been monitored in some dwellings selected randomly in the study area. Results show that the values of radon ((222)Rn) varied from 21 to 79 Bq m(-3), with a geometric mean of 45 Bq m(-3) [geometric standard deviation (GSD 1.39)], and those of thoron ((220)Rn) from minimum detection level to 58 Bq m(-3) with a geometric mean of 19 Bq m(-3) (GSD...
Review of Scientific Instruments
Radiation Effects and Defects in Solids
Radiation Effects and Defects in Solids, 2017
Journal of Nuclear Physics, Material Sciences, Radiation and Applications, 2014
The present studies aimed to investigate the effects of energy dependence of parameters character... more The present studies aimed to investigate the effects of energy dependence of parameters characterizing multiply backscattering of gamma photons. The numbers of multiply backscattered events are found to be increasing with thickness of copper target, and saturate for a particular thickness known as saturation thickness. The saturation thickness is found to be decreasing with increase in incident gamma photon energy, and also is not altered by the variation in collimator opening. The number, energy and dose albedos, characterizing the reflection probability of a material, are also evaluated. For each of the incident gamma photon energy, the number and energy albedos show an increase with increasing target thickness, and finally saturate. Monte Carlo calculations support the results of present experimental work.
Indian journal of pediatrics, 2005
We report a case of congenital tuberculosis diagnosed by liver biopsy in a 8-week-old infant pres... more We report a case of congenital tuberculosis diagnosed by liver biopsy in a 8-week-old infant presented with acute abdomen. Liver biopsy showed multiple lymphoepitheloid cell granulomas with Langhans' giant cells and central necrosis. The culture of caseous material from the liver showed Mycobacterium tuberculosis . Antituberculous treatment was started. Endometrial biopsy in the asymptomatic mother confirmed the source of infection.
Indian Journal of Physics, 2009
Page 1. Indian J. Phys. 83(8) 1141-1146 (2009) © 2009 IACS *Corresponding Author Experimental eva... more Page 1. Indian J. Phys. 83(8) 1141-1146 (2009) © 2009 IACS *Corresponding Author Experimental evaluation of multiple Compton backscattering of gamma rays in copper Arvind D Sabharwal*, Manpreet Singh, Bhajan Singh ...
EPJ Web of Conferences, 2012
Radioactivity, natural and man-made, is omnipresent in the earth's crust in different amounts. Na... more Radioactivity, natural and man-made, is omnipresent in the earth's crust in different amounts. Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity levels in soil to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. 226 Ra, 232 Th and 40 K analysis has been carried out in soil samples collected from some areas of Punjab, India using gamma-ray spectrometry. The technique of gamma ray spectrometry was applied using high purity germanium gamma-ray detector and a PC based MCA. Radium equivalent activities are calculated for the analyzed samples to assess radiation hazards arising due to the use of these soil samples in construction of dwellings. The measured activity in the soil ranges from 23.17 to 57.87 Bq kg −1 , 59.03 to 160.40 Bq kg −1 and 228.06 to 501.03 Bq kg −1 for 226 Ra, 232 Th and 40 K with mean values of 37.93, 84.47 and 351.17 Bq kg −1 respectively. It has been observed that on the average the outdoor terrestrial gamma air absorbed dose rate is about 84.65 nGy h −1 .
Radiation Measurements, 2009
The present studies aimed to investigate the effects of detector collimation and target thickness... more The present studies aimed to investigate the effects of detector collimation and target thickness on multiply backscattered gamma photons. The numbers of multiply backscattered events, having energy the same as in singly scattered distribution, are found to be increasing with target thickness, and saturate for a particular thickness known as saturation thickness. The saturation thickness is not altered by the
Radiation Effects and Defects in Solids, 2011
ABSTRACT The backscattered peak and albedos are important for the estimation of exposure distribu... more ABSTRACT The backscattered peak and albedos are important for the estimation of exposure distribution and for better understanding the phenomenon of the backscattering of gamma photons. To characterize the backscattering probability of gamma photons interacting with different atomic numbers (Z), number (A N), energy (A E) and dose (A D) albedos are experimentally evaluated. The response function converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. For each of the incident gamma photon energies, the number and energy albedos show an increase with the increasing target thickness, and finally saturate. The energy albedos are found to be decreasing with the increase in the atomic number of the target material and incident gamma photon energy. The dose albedos do not differ significantly from the energy albedos for the chosen incident gamma photon energies.
Physica Scripta, 2011
Page 1. Multiple backscattering on monoelemental materials and albedo factors of 279, 320, 511 an... more Page 1. Multiple backscattering on monoelemental materials and albedo factors of 279, 320, 511 and 662 keV gamma photons This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 Phys. Scr. 83 025303 ...
Journal of Physics: Conference Series, 2011
Page 1. Investigations of energy dependence of saturation thickness of multiply backscattered gam... more Page 1. Investigations of energy dependence of saturation thickness of multiply backscattered gamma photons in elements and alloys - an inverse matrix approach This article has been downloaded from IOPscience. Please scroll down to see the full text article. ...
Isotopes in environmental and health studies, 2011
Radon concentration levels in water and soil gas from 36 locations pertaining to some areas of Ma... more Radon concentration levels in water and soil gas from 36 locations pertaining to some areas of Malwa region of Punjab have been measured on an in situ basis using a continuous active radon detector (AlphaGuard, Model - PQ 2000 PRO, Genitron instruments, Germany). Exhalation rate measurements have also been carried out at these places, using a closed-circuit technique. The radon concentrations in soil and water varied from 1.9 to 16.4 kBq m(-3) and 5.01 to 11.6 kBq m(-3), respectively. The exhalation rate (E (Rn)) ranged between 7.48 and 35.88 mBq m(-2) s(-1) with an average value of 18.17 mBq m(-2) s(-1). Annual dose rates have been calculated for water radon concentrations. The minimum to maximum values of dose rates were found to be 13.42-31.08 μSv y(-1). The recorded values of radon concentration in water are within the safe limit of 11 Bq l(-1) recommended by the US Environment Protection Agency [National Research Council, Risk Assessment of Radon in Drinking Water (Academy Pres...
Radiation protection dosimetry, 2012
LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for est... more LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for estimating radon ((222)Rn) and thoron ((220)Rn) concentrations in dwellings of south-western Punjab, India. The present study region has shown pronounced cases of cancer incidents in the public [Thakur, Rao, Rajwanshi, Parwana and Kumar (Epidemiological study of high cancer among rural agricultural community of Punjab in Northern India. Int J Environ Res Public Health 2008; 5(5):399-407) and Kumar et al. (Risk assessment for natural uranium in subsurface water of Punjab state, India. Hum Ecol Risk Assess 2011;17:381-93)]. Radon being a carcinogen has been monitored in some dwellings selected randomly in the study area. Results show that the values of radon ((222)Rn) varied from 21 to 79 Bq m(-3), with a geometric mean of 45 Bq m(-3) [geometric standard deviation (GSD 1.39)], and those of thoron ((220)Rn) from minimum detection level to 58 Bq m(-3) with a geometric mean of 19 Bq m(-3) (GSD...
Review of Scientific Instruments