Papers by Anupam Bharadwaj
Neutrons are useful in a variety of modern day applications , spanning from laboratory
investigat... more Neutrons are useful in a variety of modern day applications , spanning from laboratory
investigations, to national energy ,or security and medical treatment. Therefore productions
of neutrons and their study is of very much helpful in developing the modern day science.
In this project the neutrons are produced by a neutron source called Neutron Howitzer
having Am-Be source with an activity of 4.6 curie at present. Indium (In115) foils of 99.99 %
purity with dimension (2.5 cm x 2.5 cm x 0.03 cm) are introduced through the holes of the
Howitzer for neutron exposure. A fraction of neutrons passing through the Indium foils get
absorbed, producing radioactive Indium (49In116*), which decay with a half-life of 54.12
minutes. After exposing 3 foils separately for 2.34, 3.75, 3.42 hours respectively, the foils
are taken out and counts were taken for 1, 1 and ½ hour respectively using a GM counter.
The process is repeated for an arrangement of the same 3 foils sandwiched together of
thickness 0.03 cm by exposing the same for 2.65 hours and taking counts for 1 hour. From
this readings we have calculated the flux of the Howitzer. This is a standard experiment
performed in the MSc Nuclear physics Lab , in the Department of Physics, Gauhati
University. Further to be added we have simulated the process of neutron transmission and
absorption through the Indium foils using Monte Carlo Method. In short, Monte Carlo is a
statistical method where a real process is simulated using random numbers in a computer.
In the simulation we have considered the flux calculated from the experiment. At the same
time we have also considered the neutron absorption and scattering process with known
cross sections. Simulation programs include: 1. Neutron transmission and absorption. 2.
Production of radioactive isotope (49In116*) and subsequent decay. These are run for different
experimental parameters and are compared with the analytical and experimental results. The
simulation of neutron transmission and absorption gives a clear information about the
dependency of the probabilities of transmission and absorption on the thickness if we
consider samples of similar chemical composition (since here we have used Indium (In115)
foils only). Also the comparison of the analytical results with the simulation program for
neutron transmission and absorption produces nearly the same result. Secondly, the
simulation program for radioactive isotope production and decay has produced plots that is
similar to the theoretically predicted plots. Also to be added, the measurement error due to
G M counting affects the uncertainty in the measuring the neutron flux. From our overall
study, we have found that Monte Carlo method can simulate the phenomenon of neutrons
absorption and transmission very successfully. Starting from the fundamental law of
radioactivity, and interaction cross section, the whole process of continuous neutron
absorption, creating radioactive isotope and subsequent decay can be simulated using
computer generated random numbers in perfect agreement with experiment.
Synchronization and clock recovery in a ferroelectric liquid crystal spatial light modulator based free-space optical communication link
Review of Scientific Instruments, May 1, 2023
Synchronization of the transmitter and receiver is crucial in a free-space optical communication ... more Synchronization of the transmitter and receiver is crucial in a free-space optical communication system for the proper transfer and retrieval of user information. In this work, we propose a method for the synchronization and recovery of the clock signal at the receiver from the optical signal modulated by a ferroelectric liquid crystal spatial light modulator (FLCSLM) in the transmitter. We have demonstrated our scheme by building an experimental arrangement that comprises an FLCSLM based computer generated holography assembly for modulating the laser beam in the transmitter and a photodiode cum micro-controller circuit in the receiver to generate the synchronized clock. We present the experimental results to demonstrate the accuracy of the recovered clock and the successful retrieval of the transmitted user information. The scheme can work for amplitude modulated, phase modulated, or complex amplitude modulated information transfer based on the FLCSLM.
Synchronization and clock recovery in a ferroelectric liquid crystal spatial light modulator based free-space optical communication link
Review of Scientific Instruments
Synchronization of the transmitter and receiver is crucial in a free-space optical communication ... more Synchronization of the transmitter and receiver is crucial in a free-space optical communication system for the proper transfer and retrieval of user information. In this work, we propose a method for the synchronization and recovery of the clock signal at the receiver from the optical signal modulated by a ferroelectric liquid crystal spatial light modulator (FLCSLM) in the transmitter. We have demonstrated our scheme by building an experimental arrangement that comprises an FLCSLM based computer generated holography assembly for modulating the laser beam in the transmitter and a photodiode cum micro-controller circuit in the receiver to generate the synchronized clock. We present the experimental results to demonstrate the accuracy of the recovered clock and the successful retrieval of the transmitted user information. The scheme can work for amplitude modulated, phase modulated, or complex amplitude modulated information transfer based on the FLCSLM.
Study of Velocity Distribution of Thermionic electrons with reference to Triode Valve
Velocity distribution of the elements of a thermodynamic system at a given temperature is an impo... more Velocity distribution of the elements of a thermodynamic system at a given temperature is an important phenomenon. This phenomenon is studied critically by several physicists with reference to different physical systems. Most of these studies are carried on with reference to gaseous thermodynamic systems. Basically velocity distribution of gas molecules follows either Maxwell-Boltzmann or Fermi-Dirac or Bose-Einstein Statistics. At the same time thermionic emission is an important phenomenon especially in e lectronics. Vacuum devices in electronics are based on this phenomenon. Different devices with different techniques use this phenomenon for their working. Keeping all these in mind we decided to study the velocity distribution of the thermionic electrons emitted by the cathode of a triode valve. From our work we have found the velocity distribution of the thermionic electrons to be Maxwellian.
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Papers by Anupam Bharadwaj
investigations, to national energy ,or security and medical treatment. Therefore productions
of neutrons and their study is of very much helpful in developing the modern day science.
In this project the neutrons are produced by a neutron source called Neutron Howitzer
having Am-Be source with an activity of 4.6 curie at present. Indium (In115) foils of 99.99 %
purity with dimension (2.5 cm x 2.5 cm x 0.03 cm) are introduced through the holes of the
Howitzer for neutron exposure. A fraction of neutrons passing through the Indium foils get
absorbed, producing radioactive Indium (49In116*), which decay with a half-life of 54.12
minutes. After exposing 3 foils separately for 2.34, 3.75, 3.42 hours respectively, the foils
are taken out and counts were taken for 1, 1 and ½ hour respectively using a GM counter.
The process is repeated for an arrangement of the same 3 foils sandwiched together of
thickness 0.03 cm by exposing the same for 2.65 hours and taking counts for 1 hour. From
this readings we have calculated the flux of the Howitzer. This is a standard experiment
performed in the MSc Nuclear physics Lab , in the Department of Physics, Gauhati
University. Further to be added we have simulated the process of neutron transmission and
absorption through the Indium foils using Monte Carlo Method. In short, Monte Carlo is a
statistical method where a real process is simulated using random numbers in a computer.
In the simulation we have considered the flux calculated from the experiment. At the same
time we have also considered the neutron absorption and scattering process with known
cross sections. Simulation programs include: 1. Neutron transmission and absorption. 2.
Production of radioactive isotope (49In116*) and subsequent decay. These are run for different
experimental parameters and are compared with the analytical and experimental results. The
simulation of neutron transmission and absorption gives a clear information about the
dependency of the probabilities of transmission and absorption on the thickness if we
consider samples of similar chemical composition (since here we have used Indium (In115)
foils only). Also the comparison of the analytical results with the simulation program for
neutron transmission and absorption produces nearly the same result. Secondly, the
simulation program for radioactive isotope production and decay has produced plots that is
similar to the theoretically predicted plots. Also to be added, the measurement error due to
G M counting affects the uncertainty in the measuring the neutron flux. From our overall
study, we have found that Monte Carlo method can simulate the phenomenon of neutrons
absorption and transmission very successfully. Starting from the fundamental law of
radioactivity, and interaction cross section, the whole process of continuous neutron
absorption, creating radioactive isotope and subsequent decay can be simulated using
computer generated random numbers in perfect agreement with experiment.