Purushottam Chakraborty | |
---|---|
Born | 1953 Kolkata |
Nationality | Indian |
Alma mater | Brahmananda Keshab Chandra College, Presidency College, Kolkata, University of Calcutta |
Known for | Secondary Ion Mass Spectrometry, Ion Beam Analysis of Materials and Photonics |
Purushottam Chakraborty is an Indian physicist who is one of the renowned experts in materials analysis using ion beams and secondary ion mass spectrometry (SIMS). [1] [2]
He is a former senior professor of Physics at Saha Institute of Nuclear Physics, Kolkata, India [3] & former adjunct professor of Physics at University of Pretoria, South Africa. [4]
Prof Chakraborty did his Ph.D. on the "Design and development of a radio-frequency (RF) quadrupole mass spectrometer (QMS) for the study of secondary-ions emitted from ion-bombarded metal surfaces". The QMS was initially fabricated by Profs S D Dey, S B Karmohapatro and B M Banerjee at Saha Institute of Nuclear Physics, Kolkata, India.
Prof Chakraborty upgraded the equipment by appropriately lowering the frequency of the RF voltage so that the QMS could handle the masses above 200 amu and also by converting the system into a full-fledged UHV-based Secondary Ion Mass Spectrometry (SIMS) Setup at Saha Institute of Nuclear Physics, Kolkata. Making use of the indigenous SIMS instrument, he initiated the experimental research on Ion-Matter Interactions, for which he was awarded "Premchand Roychand Scholarship (PRS)" and conferred "Mouat Medal" by the University of Calcutta in 1986. Later, he pursued research on Atomic Collisions in Solids, Inelastic Ion-Surface Collisions and Ion-Beam Modifications & Analysis of Materials. His other research areas include Low-Dimensional Materials and Nanoscale Systems, X-UV Optics, Optoelectronics, Nonlinear Optics, Photonics, Plasmonics, etc.
Prof Chakraborty's work on the fabrication of ‘layered Synthetic Microstructures (LSM)’, at the FOM-Institute for Atomic and Molecular Physics – Amsterdam (AMOLF), in collaboration with the Philips Research Laboratories Netherlands, was recognized as a pioneering contribution in the "realization of optical devices for the extreme ultraviolet to soft X-rays". [5] [6]
The methodology of fabricating aspherically-curved mirrors for reflecting soft x-rays at near-normal incidence was employed to construct ‘Soft X-ray Telescopes’ for imaging Solar Corona and Solar Flakes in the X-UV domain of electromagnetic spectrum. The European Space Agency, Netherlands also used this technique for reflecting X-rays with wavelengths of 1.85 and 10 to 17 Angstroms.
Prof. Chakraborty's "Alkali-element based MCsn+ Molecular-ion SIMS" approach has been used for the quantitative analysis of materials without calibration standards, in general and for the composition analysis of surfaces and interfaces of ultrathin films, superlattices and nanostructured materials, in particular. The technique has been recognized as an important contribution in the field of ion-beam analysis of materials. [7]
Prof Chakraborty's work on ‘Ion-beam Synthesis of Metal-Glass Nanocomposites’ has led to the development of novel photonic materials, thereby opening the way for advances in all-optical switching, coupled waveguides and optical computation. [8] [9]
Professor Chakraborty visited and delivered invited lectures at various renowned universities and research institutes across the globe such as Imperial College London, UK; Vanderbilt University, USA; [10] Yale University, USA; Asian Institute of Technology, Thailand; [11] Kyoto University, Japan; and CERN (Geneva), Switzerland [12] to name a few.
Prof Chakraborty was the visiting professor of Pontifical Catholic University of Rio de Janeiro, Brazil; Osaka Electro-Communication University, Japan; Universite Laval, Quebec, Canada; Friedrich Schiller University, Jena, Germany; University of Padova, Italy; International Centre for Theoretical Physics (ICTP), Trieste, Italy; FOM - Institute for Atomic and Molecular Physics, The Netherlands to name a few.[ citation needed ]
Prof Chakraborty organized and delivered keynote address at various international conferences; to name a few:
Purushottam Chakraborty has published more than 120 research papers in international journals that includes monographs, reviews and book-chapters.
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Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum.
An ion source is a device that creates atomic and molecular ions. Ion sources are used to form ions for mass spectrometers, optical emission spectrometers, particle accelerators, ion implanters and ion engines.
Gold fingerprinting is a method of identifying an item made of gold based on the impurities or trace elements it contains.
Wavelength-dispersive X-ray spectroscopy is a non-destructive analysis technique used to obtain elemental information about a range of materials by measuring characteristic x-rays within a small wavelength range. The technique generates a spectrum in which the peaks correspond to specific x-ray lines and elements can be easily identified. WDS is primarily used in chemical analysis, wavelength dispersive X-ray fluorescence (WDXRF) spectrometry, electron microprobes, scanning electron microscopes, and high precision experiments for testing atomic and plasma physics.
A microprobe is an instrument that applies a stable and well-focused beam of charged particles to a sample.
Elemental analysis is a process where a sample of some material is analyzed for its elemental and sometimes isotopic composition. Elemental analysis can be qualitative, and it can be quantitative. Elemental analysis falls within the ambit of analytical chemistry, the instruments involved in deciphering the chemical nature of our world.
Characterization, when used in materials science, refers to the broad and general process by which a material's structure and properties are probed and measured. It is a fundamental process in the field of materials science, without which no scientific understanding of engineering materials could be ascertained. The scope of the term often differs; some definitions limit the term's use to techniques which study the microscopic structure and properties of materials, while others use the term to refer to any materials analysis process including macroscopic techniques such as mechanical testing, thermal analysis and density calculation. The scale of the structures observed in materials characterization ranges from angstroms, such as in the imaging of individual atoms and chemical bonds, up to centimeters, such as in the imaging of coarse grain structures in metals.
Institute of Physics, Bhubaneswar is an autonomous research institution of the Department of Atomic Energy (DAE), Government of India. The institute was founded by Professor Bidhu Bhusan Das, who was Director of Public Instruction, Odisha, at that time. Das set up the institute in 1972, supported by the Government of Odisha under the patronage of Odisha's education minister Banamali Patnaik, and chose Dr. Trilochan Pradhan as its first director, when the Institute started theoretical research programs in the various branches of physics. Other notable physicists in the institute's early days included Prof. T. P. Das, of SUNY, Albany, New York, USA and Prof. Jagdish Mohanty of IIT Kanpur and Australian National University, Canberra. In 1981, the Institute moved to its present campus near Chandrasekharpur, Bhubaneswar. It was taken over by the Department of Atomic Energy, India on 25 March 1985 and started functioning as an autonomous body.
Gas cluster ion beams (GCIB) is a technology for nano-scale modification of surfaces. It can smooth a wide variety of surface material types to within an angstrom of roughness without subsurface damage. It is also used to chemically alter surfaces through infusion or deposition.
Static secondary-ion mass spectrometry, or static SIMS is a secondary ion mass spectrometry technique for chemical analysis including elemental composition and chemical structure of the uppermost atomic or molecular layer of a solid which may be a metal, semiconductor or plastic with insignificant disturbance to its composition and structure. It is one of the two principal modes of operation of SIMS, which is the mass spectrometry of ionized particles emitted by a solid surface upon bombardment by energetic primary particles.
Semiconductor characterization techniques are used to characterize a semiconductor material or device. Some examples of semiconductor properties that could be characterized include the depletion width, carrier concentration, carrier generation and recombination rates, carrier lifetimes, defect concentration, and trap states.
Instrumental analysis is a field of analytical chemistry that investigates analytes using scientific instruments.
The following outline is provided as an overview of and topical guide to biophysics:
Nuclear forensics is the investigation of nuclear materials to find evidence for the source, the trafficking, and the enrichment of the material. The material can be recovered from various sources including dust from the vicinity of a nuclear facility, or from the radioactive debris following a nuclear explosion.
Operando spectroscopy is an analytical methodology wherein the spectroscopic characterization of materials undergoing reaction is coupled simultaneously with measurement of catalytic activity and selectivity. The primary concern of this methodology is to establish structure-reactivity/selectivity relationships of catalysts and thereby yield information about mechanisms. Other uses include those in engineering improvements to existing catalytic materials and processes and in developing new ones.
The index of physics articles is split into multiple pages due to its size.
Resonance ionization is a process in optical physics used to excite a specific atom beyond its ionization potential to form an ion using a beam of photons irradiated from a pulsed laser light. In resonance ionization, the absorption or emission properties of the emitted photons are not considered, rather only the resulting excited ions are mass-selected, detected and measured. Depending on the laser light source used, one electron can be removed from each atom so that resonance ionization produces an efficient selectivity in two ways: elemental selectivity in ionization and isotopic selectivity in measurement.