@physics.aec.ac.in
Assistant Professor, Department of Physics
Assam Engineering College
Radiation, Nuclear Energy and Engineering, Multidisciplinary, Surfaces, Coatings and Films
Scopus Publications
Scholar Citations
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D. Bhattacharjee, N. Buzarbaruah, and S. R. Mohanty
AIP Publishing
Table-top neutron/x-ray sources are of great interest for uses in neutron activation analyses, in neutron/x-ray radiography, and also in medical applications. Inertial electrostatic confinement fusion (IECF) is a multiple neutron source that can emit neutrons, protons, x rays, etc., as basic products when operated in both continuous and pulsed modes. In this work, D-D neutrons are produced in the steady-state mode using a cylindrical IECF device. The neutron production rate has been optimized by using cathodes having different dimensions and geometrical transparencies. The maximum neutron production rate is found to be approaching 107n/s, using a cathode having eight grid wires and a diameter of 3 cm. The neutrons are successfully used for neutron activation analysis of materials containing explosive elements. X-ray spectrum having a wide range of photon energies (30–70 keV) has been detected from this device while operated in the continuous mode. X-ray radiography of high density objects has also been performed and reported for the first time using the cylindrical IECF source with negative polarity of the central grid in this paper.
S. R. Mohanty, N. Buzarbaruah, D. Bhattacharjee, and D. Jigdung
AIP Publishing
Tabletop and compact fusion sources are in much demand because of their efficiency in producing mono- energetic particles that find application in various societal usages. Inertial Electrostatic Confinement Fusion (IECF) based source, in particular, stands as one of the vital sources for producing neutrons, protons, X-rays, etc. The most promising applications of the device include neutron activation analyses (NAA), neutron radiography, medical isotope production, explosive detection, etc. IECF is basically a fusion concept wherein the lighter fuel ions (deuterium, tritium) are trapped in a converging electrostatic field inside a cylindrical or spherical geometry. A cylindrical IECF device is in operation at our center and it has been emitting a copious amount of 2.45 MeV DD fusion neutrons. The device primarily consists of a cylindrical wire grid electrode assembly housed inside a cylindrical vacuum chamber, a gas insertion system, a high voltage feedthrough, and a high voltage power supply of negative polarity. On the application of a high negative potential of few tens of kV (∼ 80 kV) to the inner grid of the device, the energetic ions overcome the coulomb barrier force and thus fuse together to produce neutrons of the order 106 n s−1. The emitted neutrons from the device are characterized by employing various detectors such as neutron area monitor, He-3 proportional counter, bubble dosimeters etc. The neutrons emitted from the device were utilized for the detection of explosive. The detailed results are discussed in the paper.
D. Bhattacharjee, N. Buzarbaruah, S. R. Mohanty, and S. Adhikari
American Physical Society (APS)
The kinetic analyses are quite important when it comes to understanding the particle behavior in any device as they start to deviate from a continuum nature. In the present study, kinetic simulations are performed using the particle-in-cell method to analyze the behavior of ions inside a cylindrical inertial electrostatic confinement fusion (IECF) device which is being developed as a tabletop neutron source. Here, the lighter ions, like deuterium, are accelerated by applying an electrostatic field between the chamber wall (anode) and the cathode (cylindrical gridded wire), placed at the center of the device. The plasma potential profiles obtained from the simulated results indicate the formation of multiple potential well structures inside the cathode grid depending upon the applied cathode potential (from -1 to -5 kV). The ion density at the core region of the device is found to be of the order of 10^{16}m^{-3}, which closely resembles the experimental observations. Spatial variation of ion energy distribution function has been measured in order to observe the characteristics of ions at different cathode voltages. Finally, the simulated results are compared and found to be in good agreement with the experimental profiles. The present analysis can serve as a reference guide to optimize the technological parameters of the discharge process in IECF devices.
D. Bhattacharjee, D. Jigdung, N. Buzarbaruah, S. R. Mohanty, and H. Bailung
AIP Publishing
An experiment on the formation of virtual electrode and ion sheath characteristics has been carried out in a hot cathode discharge plasma produced inside a cylindrical inertial electrostatic confinement fusion device. The plasma parameters such as electron temperature and plasma density are evaluated by using a Langmuir probe. Transition from a single potential well to multiple potential wells, i.e., virtual electrodes inside the cathode grid, is observed when the bias voltage applied to the cathode is increased from –1000 to –5000 V. An emissive probe has been used for the measurement of plasma potential due to its greater accuracy than the conventional Langmuir probe. Ion sheath potential structures and presheath characteristics for different cathode potentials have been investigated using the emissive probe and are found to be consistent with the Debye sheath model. A detailed discussion on the obtained results has been presented in this paper.
N. Buzarbaruah, S.R. Mohanty, and E. Hotta
Elsevier BV
N.J. Dutta, S.R. Mohanty, N. Buzarbaruah, M. Ranjan, and R.S. Rawat
Elsevier BV
N. Buzarbaruah, N.J. Dutta, D. Borgohain, S.R. Mohanty, and H. Bailung
Elsevier BV
N.J. Dutta, S.R. Mohanty, and N. Buzarbaruah
Elsevier BV
N. Buzarbaruah, N.J. Dutta, J.K. Bhardwaz, and S.R. Mohanty
Elsevier BV
N.J. Dutta, N. Buzarbaruah, and S.R. Mohanty
Elsevier BV