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Study of nuclear tracks on different polycarbonate foils and their feasibility for use in personnel monitoring
No full textCR-39 (PADC) a Solid State Nuclear Track Detector., is used as a routine
personnel monitor. 1800 workers are being monitored quarterly for fast neutron using
CR-39 foils. These foils procured from Pershore Mouldings, UK are very expensive and
indigenous development will make the foils cost effective. The aim of this paper is
to find a suitable alternative to the imported CR-39 foils for use in personnel
monitoring. The foils from three different manufacturers have been compared with the
CR-39 foils from Pershore Moulding, UK, presently in use. Out of the three, only
sample no 1 is promising. It has a background and sensitivity comparable with CR-39
presently used. The sample 2 is CR-39 being developed in India, has a relatively
high background and poor sensitivity. Efforts are being made to improve the quality
of this sample. The sample 3 was a poly carbonate from local manufacturer which
produced very few tracks and the standard deviation of track counts was very large
and hence not useful for Personnel Monitoring.Study of nuclear tracks on different polycarbonate foils and their feasibility for
use in personnel monitoring
V Jayalaskmi*, Rupali Rohatgi, Deepa Sathian, P K Marathe, Sarala Nair,
G Chourasiya and S Kannan
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre,
Mumbai-400 085, India
E-mail : [email protected] Physics and Advisory Division, Bhabha Atomic Research Centre,
Mumbai-400 085, Indi
Factors affecting the registration and counting of alpha tracks in solid state nuclear track detectors
No full textIn view of the fact that the radon progeny contribute the highest to the
natural radiation dose to general populations, large scale and long-term
measurements of radon and its progeny in the houses have been receiving considerable
attention. Solid State Nuclear Track Detector (SSNTD) based systems, being the best
suited for large scale passive monitoring, have been widely used for the radon gas
(using a cup closed with a semi-permeable membrane) and to a limited extent, for the
measurement of radon progeny (using bare mode in conjunction with the cup). These
have been employed for radon mapping and indoor radon epidemiological studies with
good results. In this technique, alpha tracks recorded on SSNTD films are converted
to radon/thoron concentrations using corresponding conversion factors obtained from
calibration experiments carried out in controlled environments.
The detector response to alpha particles depends mainly on the registration
efficiency of the alpha tracks on the detector films and the subsequent counting
efficiency. While the former depends on the exposure design, the latter depends on
the protocols followed for developing and counting of the tracks. The paper
discusses on parameters like etchant temperature, stirring of the etchant and
duration of etching and their influence on the etching rates on LR-115 films.
Concept of break down thickness of the SSNTD film in spark counting technique is
discussed with experimental results. Error estimates on measurement results as a
function of background tracks of the films are also discussed in the paper.Factors affecting the registration and counting of alpha tracks in solid state
nuclear track detectors
K P Eappen* and Y S Mayya
Environmental Assessment Division, Bhabha Atomic Research Centre, Mumbai-400 085,
India
E-mail : [email protected] Assessment Division, Bhabha Atomic Research Centre, Mumbai-400 085,
Indi
Electrochemical etching technique for neutron dosimetry
No full textIn the present work we have employed allyl diglycol carbonate (CR-39) and
cellulose triacetate (CTA) plastic for detection of neutron recoil tracks without
radiator. For CR-39, the results reveal that registration efficiency is a function
of duration of chemical pre-etching and the best results are obtained with chemical
pre-etching of 3 hours. It was also investigated that the ac field strength of 28
kV/cm having 2.5 kHz frequency was optimum for revelation of tracks. Interestingly
the sensitivity is fluence dependent and it was constant up to a fluence of about
108 n.cm2. The sensitivity abruptly decreased with increased fluence. At optimum
experimental conditions the minimum detection limit for CR-39 was found to be 0.47
mSv. For CTA, the tracks have been revealed by electrochemical etching (ECE) only
and the minimum detection limit was found to be 0.85 mSv at optimum experimental
parameters.Electrochemical etching technique for neutron dosimetry
Ravi Chand Singh1*, Manwinder Singh2 and H S Virk3
1Department of Physics, Guru Nanak Dev University, Amritsar-143 005, Punjab, India
2Chemistry Division, Irrigation & Power Research Institute, Amritsar-143 001,
Punjab, India
3360, Sector 71, Mohali-160 071, Punjab, India
E-mail : [email protected] of Physics, Guru Nanak Dev University, Amritsar-143 005, Punjab, India
2Chemistry Division, Irrigation & Power Research Institute, Amritsar-143 001,
Punjab, India
3360, Sector 71, Mohali-160 071, Punjab, Indi
Solitons of the KP equation in dusty plasma with variable dust charge and two temperature ions : energy and stability
No full textThe propagation of nonlinear waves in dusty plasmas with variable dust
charge and two temperature ions is analyzed. By using the reductive perturbation
theory, the Kadomtsev-Petviashivili (KP) equation is derived. A Sagdeev potential
has been investigated. This potential is used to study the stability conditions for
existence of solitonic solutions. Also, it is shown that a rarefactive soliton can
exist in most of the cases. The energy of the soliton has been calculated and by
using the standard normal-mode analysis a linear dispersion relation has been
obtained. The effects of variable dust charge on the amplitude, width and energy of
soliton and its effects on the angular frequency of linear wave are also discussed.Solitons of the KP equation in dusty plasma with variable dust charge and two
temperature ions : energy and stability
Hamid Reza Pakzad* and Kurosh Javidan1
Department of Physics, Azad University of Bojnourd, Bojnourd, Iran
1Department of Physics, Ferdowsi University of Mashhad, 91775-1436 Mashhad, Iran
E-mail : [email protected] of Physics, Azad University of Bojnourd, Bojnourd, Iran
1Department of Physics, Ferdowsi University of Mashhad, 91775-1436 Mashhad, Ira
Effect of neutron-irradiation on optical properties of SiO2-Na2O-MgO-Al2O3 glasses
No full textSilica based glasses are used as nuclear shielding materials. The effect of radiation on these
glasses varies as per the constituents used in these glasses. Glasses of different composition of SiO2-Na2OMgO-
Al2O3 were made by melt casting techniques. These glasses were irradiated with neutrons of different
fluences. Optical absorption measurements of neutron-irradiated silica based glasses were performed at room
temperature (RT) to detect and characterize the induced radiation damage in these materials. The absorption
band found for neutron-irradiated glasses are induced by hole type color centers related to non-bridging oxygen
ions (NBO) located in different surroundings of glass matrix. Decrease in the transmittance indicates the formation
of color-center defects. Values for band gap energy and the width of the energy tail above the mobility gap have
been measured before and after irradiation. The band gap energy has been found to decrease with increasing
fluence while the Urbach energy shows an increase. The effects of the composition of the glasses on these
parameters have been discussed in detail in this paper.Amanpreet Kaur Sandhu1, Surinder Singh1* and Om Prakash Pandey2
1Department of Physics, Guru Nanak Dev University, Amritsar-143 005, Punjab, India
2School of Physics and Materials Science, Thapar University, Patiala-147 004, Punjab, India
E-mail : [email protected] of Physics, Guru Nanak Dev University, Amritsar-143 005, Punjab, India
School of Physics and Materials Science, Thapar University, Patiala-147 004, Punjab, Indi
Dispersion of quasi-particles in high Tc cuprates
No full textThe interplay between superconductivity (SC) and antiferromagnetism (AFM)
is studied in strongly correlated systems of high TcCuprate superconductors. It is
assumed that superconductivity arises due to BCS pairing mechanism in presence of
AFMin Culattices of Cu–Oplanes. The total Hamiltonian of the system is mean field
one and has been solved exactly by writing the equations of motion for the single
particle Green’s functions. Equations for the appropriate single particle
co-relation functions are derived and the order parameters corresponding to SC and
AFM are determined. It is assumed that the Fermi energy .F = 0 and the renormalized
localized f energy level coincide with the Fermi level. All the quantities in the
final equation for h and . are made dimensionless by dividing by 2t, where t is the
hopping integral. The temperature dependent values of staggered magnetic field (h)
and SC gap (.) were determined by solving self-consistent equations for h and .. The
quasiparticle energy bands are function of AFM gap (h), SC gap (.) and
hybridization (V ). Then the dispersion of quasi-particles are studied at different
temperatures by considering temperature dependent values of h and . and varying
other different model parameters.Author Affiliation: B N Panda, B K Sahoo1 and G C Rout
1.D A V College, Koraput-764 021, Orissa, India
2.Condensed Matter Group, Govt. Science College, Chatrapur-761 020, Orissa, India
E-mail : [email protected] A V College, Koraput-764 021, Orissa, India
2Condensed Matter Group, Govt. Science College, Chatrapur-761 020, Orissa, Indi
Trace element analysis of fly ash samples by EDXRF technique
No full textTrace element analysis of some fly ash samples and soil samples have been
carried out by Energy Dispersive X-Ray Fluorescence technique. Fourteen elements
namely K, Ca, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Sr and Pb have been quantified
in the fly ash samples by this technique. It was found that there is no huge
concentration difference between the fly ash and soil samples as a result of which
fly ash can be used as soil manure without any adverse impact on the plants.Trace element analysis of fly ash samples by EDXRF technique
T R Rautray1*, B Behera1, T Badapanda1, V Vijayan2 and S Panigrahi1
1Department of Physics, National Institute of Technology, Rourkela-769 008, Orissa,
India
2Department of Physics, Valliammai Engineering College, SRM Nagar, Chennai-603 203,
Tamil Nadu, India
E-mail : [email protected] of Physics, National Institute of Technology, Rourkela-769 008, Orissa,
India
2Department of Physics, Valliammai Engineering College, SRM Nagar, Chennai-603 203,
Tamil Nadu, Indi
Effect of thermal annealing on the structure and microstructure ofTiO2 thin films
No full textNanostructured TiO2 thin films have been prepared through chemical route
using sol-gel and spin coating techniques. The deposited films were annealed in the
temperature range 400–1000°C for 1 h. The structure and microstructure of the
annealed films were characterized by GAXRD, micro-Raman spectroscopy and AFM. The
as-deposited TiO2 thin films are found to be amorphous. Micro-Raman and GAXRD
results confirm the presence of the anatase phase and absence of the rutile phase
for films annealed up to 700°C. The diffraction pattern of the film annealed at 800
to 1000°C contains peaks of both anatase and rutile reflections. The intensity of
all peaks in micro-Raman and GAXRD patterns increased and their width (FWHM)
decreased with increasing annealing temperature, demonstrating the improvement in
the crystallinity of the annealed films. Phase transformation at higher annealing
temperature involves a competition among three events such as : grain growth of
anatase phase, conversion of anatase to rutile and grain growth of rutile phase. AFM
image of the as-deposited films and annealed films indicated exponential grain
growth at higher temperature.Effect of thermal annealing on the structure and microstructure ofTiO2 thin films
Haripriya Rath1*, S Anand2, M Mohapatra2, Priyadarshini Dash1, T Som3,
U P Singh4 and N C Mishra1
1Department of Physics, Utkal University, Bhubaneswar-751 004, Orissa, India
2Institute of Minerals and Materials Technology, Bhubaneswar-751 013, Orissa, India
3Institute of Physics, Bhubaneswar-751 005, Orissa, India
4KIIT University, Bhubaneswar-751 024, Orissa, India
E-mail : [email protected] of Physics, Utkal University, Bhubaneswar-751 004, Orissa, India
2Institute of Minerals and Materials Technology, Bhubaneswar-751 013, Orissa, India
3Institute of Physics, Bhubaneswar-751 005, Orissa, India
4KIIT University, Bhubaneswar-751 024, Orissa, India
1Department of Physics, Utkal University, Bhubaneswar-751 004, Orissa, India
2Institute of Minerals and Materials Technology, Bhubaneswar-751 013, Orissa, India
3Institute of Physics, Bhubaneswar-751 005, Orissa, India
4KIIT University, Bhubaneswar-751 024, Orissa, Indi
Track-etch membranes as templates enabled nano/micro technology : a review
No full textMany techniques are being used in order to synthesize nano.micro materials falling under the realm of nanotechnology. It need not be overemphasized that the miniaturization of devices and synthesis of new materials have a tremendous role in the development of powerful electronics as well as material based technologies in other areas but for the laws of quantum mechanics posing limitations besides the increasing cost and difficulties in manufacturing in such a small scale. The quest, therefore, for the alternative technologies, have stimulated a surge of interest in nano-meter scale materials and devices in the recent years. Metallic as well as semiconducting nano wires are the most attractive materials because of their unique properties having myriad of applications like interconnects for nano-electronics, magnetic devices, chemical and biosensors, whereas the hollow tubules are equally considered to be candidates for more potent applications both in physical as well as biosciences. Materials processing for nano-structured devices is indispensable to their rational design. The technique, known as Template Synthesis , using electrochemical.electro less deposition is one of the most important processes for manufacturing nano.micro structures, nano-composites and devices and is relatively inexpensive and simple. The technique involves using membranes ion crafted ones (popularly known as Particle Track-Etch Membranes or Nuclear Track Filters), alumite substrate membranes, besides other types of membranes as templates. The parameters viz., diameter as well as length i.e., aspect ratio, shape and wall surface traits in these membranes are controllable.
In the present article a detailed review of this technique using track-etch membranes as templates in synthesis of nano.micro materials including hybrid materials and devices like field-ion emitters, resonant tunneling diodes (RTDs) etc. is presented including most of the results obtained in our laboratory.rack-etch membranes as templates enabled nano/micro technology : a review
S K Chakarvarti
Department of Applied Physics, National Institute of Technology (Deemed University),
Kurukshetra-136 119, Haryana, India
E-mail : [email protected] of Applied Physics, National Institute of Technology (Deemed University),
Kurukshetra-136 119, Haryana, Indi
Measurement of uranium and its isotopes at trace levels in environmental samples using mass spectrometry
No full textActinides have widely entered the environment as a result of nuclear
accidents and atmospheric weapon testing. These radionuclides, especially uranium,
are outstanding radioactive pollutants, due to their high radiotoxicity and long
half-lives. In addition to this, since depleted uranium (DU) has been used in the
Balkan conflict in 1999, there has been a concern about the possible consequences of
its use for the people and environment. Therefore, accurate, precise and simple
determination methods are necessary in order to evaluate the human dose and the
concentration and effects of these nuclides in the environment. The principal
isotopes of uranium e.g.235U and 238U are of primordial origin and 234U present in
radioactive equilibrium with 238U. 236U occurs in nature at ultra trace
concentrations with a 236U : 238U atom ratio of 10–14. Concentrations of uranium in
soil samples were determined using inductively coupled plasma mass spectrometry
(ICP-MS) and isotope ratios of uranium were measured using a thermal ionisation mass
spectrometer. Radioactive dis-equilibrium of 234U.238U, depletion of 235U.238U and
significant evidence of 236U.238U were noticed in soil samples.Measurement of uranium and its isotopes at trace levels in environmental samples
using mass spectrometry
S K Sahoo
Environmental Radiation Effects Research Group, Research Centre for Radiation
Protection,
National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba
263-8555, Japan
E-mail : [email protected] Radiation Effects Research Group, Research Centre for Radiation
Protection,
National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba
263-8555, Japa