Tanmoy Bar - Academia.edu (original) (raw)

Papers by Tanmoy Bar

Journal of physics. G, Nuclear and particle physics, May 17, 2024

Journal of physics. G, Nuclear and particle physics, Apr 15, 2024

arXiv (Cornell University), Jan 11, 2024

Neutron deficient nuclei from 74 Se− 196 Hg are thought to be produced by γ-induced reactions (γ,... more Neutron deficient nuclei from 74 Se− 196 Hg are thought to be produced by γ-induced reactions (γ,n), (γ,p) and (γ, α) processes. The relatively high abundance of 113 In odd A p-nuclei has inspired to study its production processes. As reaction with γ-beam is difficult to perform in the laboratory, γ-induced reaction rate is calculated from the inverse reaction data employing reciprocity theorem. Stacked foil activation method was used to measure the 113 In(α, γ) and 113 In(α, n) reactions cross-section near the astrophysical energies. Theoretical statistical model calculations were performed with different nuclear input parameters and compared with the experimental results. An appropriate α-optical potential has been identified from the (α, γ) and (α, n) fitting, which provides the major source of uncertainty in the statistical model calculations. The other nuclear input parameters like level density, and γ-ray strength function were also constrained for theoretical calculations. 113 In(α, γ) 117 Sb and 117 Sb(α, γ) 113 In reaction rates were calculated using best-fitted input parameters.

arXiv (Cornell University), Jan 6, 2024

The cross-section measurement of 144 Sm(p, γ) 145 Eu (T 1/2 =5.93(4) days) reaction has been perf... more The cross-section measurement of 144 Sm(p, γ) 145 Eu (T 1/2 =5.93(4) days) reaction has been performed at proton energies around 2.

arXiv (Cornell University), Jan 19, 2024

The detailed process of preparing enriched 108 Cd targets on mylar and copper backing using the v... more The detailed process of preparing enriched 108 Cd targets on mylar and copper backing using the vacuum evaporation technique is described. These targets were employed in an experiment to measure the proton capture cross-section at energies significantly below the Coulomb barrier, for the astrophysical pprocess studies [1][2]. Due to the low melting point and high vapor pressure of cadmium, some adjustments were implemented in the Telemark multipocket e-beam setup. The target thickness was determined through the measurement of alpha particle energy loss from a triple alpha source and also by RBS measurements. The thickness of the 108 Cd films varies between 290 to 660 µg/cm 2 , with a non-uniformity of approximately 10%. X-ray Photoelectron Spectroscopy (XPS) and X-ray Fluorescence (XRF) analyses were conducted to examine the presence of impurities and to assess surface morphology, phase, and chemical composition.

EPJ Web of Conferences

In this article, a detailed theoretical investigation has been done on the long-lived gamma backg... more In this article, a detailed theoretical investigation has been done on the long-lived gamma background due to neutron emitting reactions. It mainly focused on the experiments that will be used to calibrate energy with the terminal voltage of an upcoming Facility for Research in Experimental Nuclear Astrophysics (FRENA). Many reactions like (p, n), (p, γ) have been utilized in various accelerator facilities around the globe for energy calibration purposes. Neutron emitting reactions like 7Li(p, n), 13C(p, n), 19F(p, n), 27Al(p, n), etc. have been very commonly used. For such reactions, a significant number of neutrons produced from such experiments can interact with surrounding elements like copper, tantalum, stainless steel (SS304 and SS316), concrete materials,etc. These interactions may create long-lived gamma activity in the vicinity of the accelerator and detection area. Background gammas from these radioactive isotopes can interfere with gamma measurements in future experiments...

arXiv (Cornell University), Mar 3, 2022

In this article, a detailed investigation has been done for the long lived gamma activity due to ... more In this article, a detailed investigation has been done for the long lived gamma activity due to neutron emitting experiments. These calculations mainly focused on the experiments used for energy calibration purposes. Calibrated energy is one of the most essential features of any accelerator facility. Several experiments have been used for this purpose. Generally, experiments having sharp curvature change in cross section of yield are used. Neutron emitting experiments are one of such. Around the globe reactions like 7 Li(p, n), 13 C(p, n), 19 F(p, n), 27 Al(p, n) etc. are used to calibrate energy of the beam with accelerator terminal voltage. Neutrons coming from these experiments can interact with surrounding elements. These interactions with neutrons can create long lived gamma activity which may interfere with future measurements. The present study has been done keeping in mind the new Facility for Research in Experimental Nuclear Astrophysics (FRENA) at Saha Institute of Nuclear Physics. It is a 3MV tandetron low energy high current machine.

Review of Scientific Instruments, 2020

In this article, a simple and efficient deuterated polyethylene target preparation method is desc... more In this article, a simple and efficient deuterated polyethylene target preparation method is described. The method of convenient removal of the targets from a casting surface without any cryogenic freezing has been adopted. The difference in thermal expansion properties of the target material and casting surface (glass) is utilized. The target thickness was determined from 3 − α energy loss in the prepared targets. The target thickness varies from 100 µg/cm2 to 350 µg/cm2. The thickness variation in these foils was between 4% and 10%. The material retention property of a deuterated foil has been verified by Fourier-transform infrared spectroscopy and an attenuated total reflection method.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2019

This work presents time-dependent numerical calculations of heat generation and dissipation in ta... more This work presents time-dependent numerical calculations of heat generation and dissipation in targets used in high ion-beam current nuclear astrophysics experiments. The simulation is beneficial for choosing the thickness of targets, maximum ion-beam current and design setup for cooling of such targets. It is found that for the very thin target (27 Al(p, p), 12 C(p, p)) heat generation inside target is relatively low and a fair amount of high current (few μA)can be used without any melting issue. But in case of thick targets (27 Al(p, γ), 12 C(p, γ)) cooling became essential for the survival of reaction target.

EPJ Web of Conferences

The majority of astrophysical reactions have very low cross-sections (nanobarn to picobarn range)... more The majority of astrophysical reactions have very low cross-sections (nanobarn to picobarn range) and significant error bars [1, 2]. Hence γ-ray background studies up to 3 MeV have been performed inside the Facility for Research in Experimental Nuclear Astrophysics (FRENA), Saha Institute of Nuclear Physics, Kolkata, India. A meticulous background calculation has been performed at different positions inside the accelerator hall and beam hall using two NaI(Tl) detectors [3]. An XPS measurement has been carried out to identify elements present in the FRENA wall concrete. Activity calculations done in [4] shows that neutrons produced by various experiments may combine with any nearby elements and form various radioactive isotopes with long half-lives, which may produce a γ-ray background .

Journal of physics. G, Nuclear and particle physics, May 17, 2024

Journal of physics. G, Nuclear and particle physics, Apr 15, 2024

arXiv (Cornell University), Jan 11, 2024

Neutron deficient nuclei from 74 Se− 196 Hg are thought to be produced by γ-induced reactions (γ,... more Neutron deficient nuclei from 74 Se− 196 Hg are thought to be produced by γ-induced reactions (γ,n), (γ,p) and (γ, α) processes. The relatively high abundance of 113 In odd A p-nuclei has inspired to study its production processes. As reaction with γ-beam is difficult to perform in the laboratory, γ-induced reaction rate is calculated from the inverse reaction data employing reciprocity theorem. Stacked foil activation method was used to measure the 113 In(α, γ) and 113 In(α, n) reactions cross-section near the astrophysical energies. Theoretical statistical model calculations were performed with different nuclear input parameters and compared with the experimental results. An appropriate α-optical potential has been identified from the (α, γ) and (α, n) fitting, which provides the major source of uncertainty in the statistical model calculations. The other nuclear input parameters like level density, and γ-ray strength function were also constrained for theoretical calculations. 113 In(α, γ) 117 Sb and 117 Sb(α, γ) 113 In reaction rates were calculated using best-fitted input parameters.

arXiv (Cornell University), Jan 6, 2024

The cross-section measurement of 144 Sm(p, γ) 145 Eu (T 1/2 =5.93(4) days) reaction has been perf... more The cross-section measurement of 144 Sm(p, γ) 145 Eu (T 1/2 =5.93(4) days) reaction has been performed at proton energies around 2.

arXiv (Cornell University), Jan 19, 2024

The detailed process of preparing enriched 108 Cd targets on mylar and copper backing using the v... more The detailed process of preparing enriched 108 Cd targets on mylar and copper backing using the vacuum evaporation technique is described. These targets were employed in an experiment to measure the proton capture cross-section at energies significantly below the Coulomb barrier, for the astrophysical pprocess studies [1][2]. Due to the low melting point and high vapor pressure of cadmium, some adjustments were implemented in the Telemark multipocket e-beam setup. The target thickness was determined through the measurement of alpha particle energy loss from a triple alpha source and also by RBS measurements. The thickness of the 108 Cd films varies between 290 to 660 µg/cm 2 , with a non-uniformity of approximately 10%. X-ray Photoelectron Spectroscopy (XPS) and X-ray Fluorescence (XRF) analyses were conducted to examine the presence of impurities and to assess surface morphology, phase, and chemical composition.

EPJ Web of Conferences

In this article, a detailed theoretical investigation has been done on the long-lived gamma backg... more In this article, a detailed theoretical investigation has been done on the long-lived gamma background due to neutron emitting reactions. It mainly focused on the experiments that will be used to calibrate energy with the terminal voltage of an upcoming Facility for Research in Experimental Nuclear Astrophysics (FRENA). Many reactions like (p, n), (p, γ) have been utilized in various accelerator facilities around the globe for energy calibration purposes. Neutron emitting reactions like 7Li(p, n), 13C(p, n), 19F(p, n), 27Al(p, n), etc. have been very commonly used. For such reactions, a significant number of neutrons produced from such experiments can interact with surrounding elements like copper, tantalum, stainless steel (SS304 and SS316), concrete materials,etc. These interactions may create long-lived gamma activity in the vicinity of the accelerator and detection area. Background gammas from these radioactive isotopes can interfere with gamma measurements in future experiments...

arXiv (Cornell University), Mar 3, 2022

In this article, a detailed investigation has been done for the long lived gamma activity due to ... more In this article, a detailed investigation has been done for the long lived gamma activity due to neutron emitting experiments. These calculations mainly focused on the experiments used for energy calibration purposes. Calibrated energy is one of the most essential features of any accelerator facility. Several experiments have been used for this purpose. Generally, experiments having sharp curvature change in cross section of yield are used. Neutron emitting experiments are one of such. Around the globe reactions like 7 Li(p, n), 13 C(p, n), 19 F(p, n), 27 Al(p, n) etc. are used to calibrate energy of the beam with accelerator terminal voltage. Neutrons coming from these experiments can interact with surrounding elements. These interactions with neutrons can create long lived gamma activity which may interfere with future measurements. The present study has been done keeping in mind the new Facility for Research in Experimental Nuclear Astrophysics (FRENA) at Saha Institute of Nuclear Physics. It is a 3MV tandetron low energy high current machine.

Review of Scientific Instruments, 2020

In this article, a simple and efficient deuterated polyethylene target preparation method is desc... more In this article, a simple and efficient deuterated polyethylene target preparation method is described. The method of convenient removal of the targets from a casting surface without any cryogenic freezing has been adopted. The difference in thermal expansion properties of the target material and casting surface (glass) is utilized. The target thickness was determined from 3 − α energy loss in the prepared targets. The target thickness varies from 100 µg/cm2 to 350 µg/cm2. The thickness variation in these foils was between 4% and 10%. The material retention property of a deuterated foil has been verified by Fourier-transform infrared spectroscopy and an attenuated total reflection method.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2019

This work presents time-dependent numerical calculations of heat generation and dissipation in ta... more This work presents time-dependent numerical calculations of heat generation and dissipation in targets used in high ion-beam current nuclear astrophysics experiments. The simulation is beneficial for choosing the thickness of targets, maximum ion-beam current and design setup for cooling of such targets. It is found that for the very thin target (27 Al(p, p), 12 C(p, p)) heat generation inside target is relatively low and a fair amount of high current (few μA)can be used without any melting issue. But in case of thick targets (27 Al(p, γ), 12 C(p, γ)) cooling became essential for the survival of reaction target.

EPJ Web of Conferences

The majority of astrophysical reactions have very low cross-sections (nanobarn to picobarn range)... more The majority of astrophysical reactions have very low cross-sections (nanobarn to picobarn range) and significant error bars [1, 2]. Hence γ-ray background studies up to 3 MeV have been performed inside the Facility for Research in Experimental Nuclear Astrophysics (FRENA), Saha Institute of Nuclear Physics, Kolkata, India. A meticulous background calculation has been performed at different positions inside the accelerator hall and beam hall using two NaI(Tl) detectors [3]. An XPS measurement has been carried out to identify elements present in the FRENA wall concrete. Activity calculations done in [4] shows that neutrons produced by various experiments may combine with any nearby elements and form various radioactive isotopes with long half-lives, which may produce a γ-ray background .