Department of Nuclear and Atomic Physics
Welcome to the Department of Nuclear and Atomic Physics! Our department
boasts of a vast and diverse canvas of experimental and theoretical research
activities ranging from nuclear structure and emergent nuclear properties, ionatom collisions, molecular dynamics, intense light-matter interactions, physicsbiology interfaces, and nano-optics. The DNAP is equipped with several state-ofthe-art equipment and facilities that enable even the obscurest of studies easily
accessible in the lab. We do take a lot of pride in building our instruments
ourselves! Given the multitude of high-profile research publications routinely
emanating from the department, you surely can expect an inspiring and a
rewarding research career in the DNAP.
Browse through the following pages to acquaint yourselves with our researchers
and their interests. We are also at http://www.tifr.res.in/~dnap.
Faculty members
Prof S N Mishra (Chair)
Prof E Krishnakumar
Prof M Krishnamurthy
Prof S V K Kumar
Prof G Ravindra Kumar
Prof Deepak Mathur
Prof Indranil Mazumdar
Dr Deepankar Misra
Prof Sushil Mujumdar
Prof Vandana Nanal
Prof Subrata Pal
Prof Rudrajyoti Palit
Prof R G Pillay
Dr Vaibhav Prabhudesai
Prof Lokesh Tribedi
Molecular Dynamics and Control Laboratory
Research Interests:
We aim to study the structure and dynamics of negative ion states of molecules, which are
formed under low energy electron-molecule interactions. These states, which generally have
lifetimes of picosecond or lower are ideal to study the mixing between electronic and nuclear
degrees of freedom, conical intersections of molecular potential energy surfaces, the role of
symmetry in orientation specific electron attachment, site specific cleavage of molecular bonds
and control of electron induced chemistry. We probe these states by selectively preparing
them at different points on their potential energy surfaces using electron beam of variable
energy or in combination with coherent population transfer technique using nanosecond or
femtosecond lasers. In addition to their very fundamental nature, these studies have
important consequences to other areas of science, technology and medicine like planetary and
space science, astrochemistry, plasma devices, nanolithography and radiation therapy.
Facilities and Equipments:
We use mass spectrometry along with a very versatile ion momentum imaging spectrometry
developed by us. UV to visible tunable nanosecond lasers and a femtosecond laser system with
pulse shaping and wavelength changing capability are used for population transfer to specific
states. A pulsed supersonic beam, specially built effusive molecular beams, custom designed
electron guns, a FTIR spectrometer and closed cycle He cryo head are other tools that we use
for probing the negative ion states in gas phase as well condensed phase .
Momentum distribution of Clfrom Cl2 produced by (a) 2.5eV
(b) 4.5 eV and (c) 6.5 eV electron
impact. The arrow indicates the
direction of the electron beam.
Recent Results:
• Control of molecular dissociation using low energy electrons: First demonstration of selective breaking
of O-H, C-H, and N-H bonds in simple organic molecules using electron energy as a control parameter.
• Unravelling the structure and dynamics of transient molecular negative ions: Developed the very first
ion momentum imaging technique to study the dynamics of transient molecular anions formed in low
energy electron molecule interaction.
• Catalytic action of low energy electrons: Demonstrated the
catalytic action of low energy electron in chemical transformation
of simple molecules by studying the resonant CO2 formation from
condensed formic acid on interaction with low energy electrons
• Electron interaction with crystalline v/s amorphous CO2 films.
• Sub-ionization low energy
Current Members:
electrons break DNA, &
E. Krishnakumar, S. V. K. Kumar, Vaibhav S. Prabhudesai,
protein
Vishvesh Tadsare, Krishnendu Gope, Sramana Kundu, Atiq-urRahman, Yogesh Upalekar, Satej Tare, Julia Chellia, Thupten Tsering
Location and Contact Details:
Room W145 (Prof. E. Krishnakumar) – Extn: 2502
Room W144 (Prof. S. V. K. Kumar) – Extn: 2400
Room P309 (Dr. Vaibhav S. Prabhudesai) – Extn: 2821
Room W140 (Lab) – Extn: 2729/2401/2043;
PhD positions available
Ultrashort Pulse High Intensity Laser Laboratory (UPHILL)
Research Interests:
Imagine the earth as a giant lens, focusing the solar energy it receives on the tip of a pencil!
Such gargantuan light intensities can be reproduced in our laboratory by a femtosecond laser
pulse. We work at the frontier of intense laser-matter interactions by exciting matter with
intense femtosecond laser pulses of terawatt peak powers.
Facilities and Equipments
• 20 terawatt, 30 femtosecond Ti-sapphire
laser
• 100 terawatt, 25 femtosecond, ‘ultrahigh
contrast’ Ti-sapphire laser
Peak intensities up to 1020 W/cm2 that can
drive electrons to relativistic speeds.
State of the art 100 TW laser that can produce stellar
conditions in laboratory
Recent Results:
Some recent publications
• Generation of picosecond-bursts of the largest terrestrial magnetic fields, nearly a billion
times that of the earth, with far-reaching implications in inertial confinement fusion and
laboratory astrophysics (Sandhu PRL 2002, Mondal PNAS 2012, Chatterjee PRL 2012).
• Table-top acceleration of neutral atoms to mega-electronvolt energies (Rajeev Nature Phys.
2013) as a result of the interaction of intense lasers with cluster nanoplasmas (Trivikram PRL
2013).
• Generation of hard x-ray pulses from nanostructures (Rajeev PRL 2003) and even bacterial
cells (Krishnamurthy Opt. Exp. 2012).
Mechanism of charge transfer in
the generation of MeV neutrals
Current members:
G. Ravindra Kumar, M. Krishnamurthy
Prashant Kumar Singh, Amitava Adak, Amit D. Lad,
P. Brijesh, Malay Dalui, Sheroy Tata, Jagannath Jha,
Moniruzzaman Shaikh, Deep Sarkar, Soubhik Sarkar
Location and Contact details:
Room B133 (Prof. G. Ravindra Kumar) – Extn: 2381
Room B114 (Prof. M. Krishnamurthy) – Extn: 2685
Room B136/137 (Lab) – Extn: 2650
Room B122 (Office) – Extn: 2745
URL: http://www.tifr.res.in/~uphill/
PhD positions available
Atomic and Molecular Sciences group
Research Interests:
Our experiments focus on ultrafast phenomena in atoms, molecules, clusters in the gas-phase
as well as atoms, molecules and biological entities in the condensed phase.
Facilities and Equipments:
• ultrafast laser pulses.. they are “on” for only 5 fs: lasting for
barely 2 optical cycles of 800 nm light!
• optical traps.. using tightly focused laser beams to create a
dipole trap…we work on LIVE single cells!
• spectroscopy integrated with traps…Raman Tweezers!
• time-of-flight spectrometry...”looking” at SINGLE ions!
• IR & fibre lasers for photonics; nonlinear optics.
Recent Results:
We create plasma channels in condensed media
for basic studies (like DNA damage caused
plasma constituents) and applications, like
“writing” waveguides and photonic structures
within glasses and other bulk materials.
• With only 2 optical cycles, the carrier envelope phase (CEP) within
a pulse becomes important: we stabilize and control it!
• This allows us to explore how ionization and dissociation of
molecules depend on CEP…opens new vistas for attosecond
dynamics. [Mathur et al., Phys. Rev. Lett. 110 (2013) 083602]
• We’ve shown that ultrafast molecular rearrangements, like proton
migration, can occur on timescales of only one vibrational period!
[Garg et al., J. Chem. Phys. 136 (2012) 024320]
• By created hot plasma in water containing DNA we’ve shown that
DNA damage can be induced by very low-energy electrons and by
OH-radicals. [D’Souza et al., Phys. Rev. Lett. 106 (2011) 118101]
• We trap healthy and malaria-infected red blood cells to probe
changes in cell membrane elasticity and birefringence.
[Dharmadhikari et al., J. Biomed. Opt. 18 (2013) 125001]
a)
b)
c)
Defeating Jahn Teller instability in a
Folding of a single red blood
polyatomic molecule, tetramethylsilane,
cell under the influence of our
using intense laser pulses lasting only 5 fs,
dipole optical trap: the folding
much shorter than typical vibrational times
dynamics depends on the
5 fs
in this molecule. As a result, the TMS
extent of malarial infection!
1
molecular ion, which is normally not
“seen”, now becomes visible in our mass
22 fs
spectrum! [Dota et al., Phys. Rev. Lett. 108
(2012) 073602]
100 fs
0
Current members:
60
70
80
90
100 110
m/q
Deepak Mathur
We also use tightly-focused laser beams Aditya Dharmadhikari, Rodney Bernard, Vijay Pawaskar
to generate nano-bubbles encrusted with Location:
carbon nanotubes (CNT); these generate B-124; also labs in SAMEER, IIT-B as well as at Manipal Univ.
broadband radiation and open new URL: www.tifr.res.in/~atmol
possibilities of highly-localized whitelight
Research positions available
therapy in biomedical environments.
Ion yield (arb.units)
2
High-energy gamma-ray lab
Research Interests:
The major activities are centred around two broad topics.
• To study the real time response of the nuclear many-body system at finite temperature and
angular momentum. This is achieved through exclusive measurements of high energy Giant
Dipole Resonance (GDR) gamma-rays. The measurements are carried out at TIFR, Mumbai
and IUAC, Delhi using state-of-the art detection facilities, namely, large volume NaI(Tl) and
LaBr3:Ce detectors, a 4p sum-spin spectrometer, and gas-filled magnetic spectrometer. Our
primary goal is to search for very rare quantum shape-phase transitions and discovering
higher order giant multipole oscillations in hot nuclei.
• Detailed theoretical investigations of the structural properties of newly discovered light
neutron-rich halo nuclei using full three-body Faddeev calculations. We search for the
elusive and fascinating Efimov effect in nuclei like, 11Li, 14Be, 20C, 36Ne, 38Mg etc.
Facilities and Equipments:
The TIFR 4p Spin-Spectrometer and high energy
g-ray setup.
The large volume LaBr3:Ce g-ray detectors
Recent Results:
2000
Measured
Simulated
E = 30 MeV
Counts
1500
1000
500
0
21000
24000
27000
30000
33000
Energy (keV)
First measurement of the linear response of
large volume LaBr3:Ce up to 22.5 MeV
monochromatic g-rays.
First measurement of monochromatic 30
MeV photons in the large cylindrical
LaBr3:Ce
compared with the GEANT4
simulation
Current members:
Indranil Mazumdar,
S. Roy, P. B. Chavan, S.M. Patel
Contact Details:
Prof. Indranil Mazumdar E-mail: indra@tifr.res.in
PhD positions available
Accelerator-based Condensed Matter Physics
Research Interests:
We study solid state phenomenon at short length and time scales using high energy heavy-ion
accelerator and hyperfine interactions as tools. A range of nuclei produced by nuclear reaction
are used to probe solid state properties at a microscopic level. The spin of these nuclei
precesses under the influence of the fields produced by the atoms of the solid (hyperfine
fields) and modulate the γ-ray intensity emitted by them. By measuring the spin precession
we obtain information regarding properties of the material. We are currently engaged in
studies of narrow band phenomenon like, magnetism and Kondo interaction, correlated
electrons, nano-metals, critical phenomenon, charge and spin fluctuation etc.
We also perform band structure calculations to support our experiments. Measurement of
nuclear moments is another area of our research activities.
Magnetism and Kondo interaction in small solids.
Atoms of transition and f-block elements carry magnetic moments described by Hund’s rule.
Solids formed from these atoms, especially the 3d metals like Cr, Mn, Fe, Co, Ni and f-block
metals (rare earth and actinide) and their alloys often show long range magnetic ordering –
ferro-, antiferro or complex. When dilute concentrations of these atoms are placed inside a
nonmagnetic solid (host), the moment may or may not survive. If it survives in an infinite
solid, will it remain intact in small solids (nano- metals)? For the last few years we have been
asking these questions and carrying out experimental and theoretical studies to find some
answers. For example, using hyperfine interaction technique we have shown conclusive
evidence that lattice size plays a decisive role not only on the formation of local moment but
also on the Kondo interaction which is directly linked to spin fluctuations. Evidence for size
induced localization of 4f electrons have also been observed in strongly correlated electron
systems.
Facilities and Equipments:
Recent Results:
Spin precession of
54Fe nuclei in
nano-Nb
Recent Publications:
Phys. Rev. Lett., 85, 1978 (2000);
Phys. Rev. Lett., 105, 147203 (2010);
Phys. Rev. B, 71, 094429 (2005);
Phys. Rev. B, 87, 125125 (2013)
A 7T; 1.5-320K experimental
set up for accelerator based
hyperfine interaction studies.
Current Members:
S. N. Mishra,
S K Mohanta, S M Davane
Location and Contact Details:
Room P114. (Lab) - Extn: 2344
Prof. S. N. Mishra Email: mishra@tifr.res.in
Ph.D positions available
Accelerator-based Atomic Physics Laboratory
Research Interests:
We, at the Accelerator Based Atomic Physics lab, mostly focus on the study of Interaction of
highly charged ions and fast electrons with simple atomic and molecular systems like H, He, H2,
complex molecular systems like C60 and large bio-molecules. We address questions related to
the quantum mechanical interference in ionization of molecules like H2 , N2 and O2 etc. Also we
study the collective behaviour of electrons in large molecules like C60. Recently, we have also
been interested in the study of fragmentation dynamics of small di- and tri-atomic molecular
systems in collisions with highly charged ions from ECRIA.
Facilities and Equipments:
We carry out our experiments with slow and highly charged ion beams from an ECR based ion
accelerator facility (ECRIA) as well as fast highly charged ion beams from the BARC-TIFR 14 MV
tandem Pelletron-Linac accelerator facility at TIFR. We use different measurement techniques
such as electron spectroscopy, time-of-flight mass spectrometry and high resolution x-ray
spectrometry. Recently we have developed a Recoil Ion Momentum Spectrometer (RIMS) to
study the fragmentation dynamics of small molecular systems.
Recent Results:
• Radiative decay of auto ionizing doubly
excited states in He like highly charged ions.
First observation of the fluorescence-active
doubly excited states in He-like Si, S, and Cl
ions measured using a bent crystal x-ray
spectrometer.
• Total ionization cross section of Uracil in
collisions with highly charged ions from
ECRIA and Pelletron. A comparative study of
total ionization cross sections measured
over a wide range of energies which covers
the Bragg peak region in hadron therapy.
ECR based Ion Accelerator at TIFR
First Hit
Second Hit
Fragmentation of N2 : Momentum Distribution
Current Members
Lokesh C. Tribedi, Deepankar Misra,
W. A. Fernandes, K. V. Thulasiram, Nilesh Mhatre,
S. Manjrekar, A. H. Kelkar, M. Rundhe, S. Nandi, A.
Khan, S. Biswas, S. Bhattacharjee
Location and Contact Details:
Room: PG-06/W-134 Extn: 2465
Prof. Lokesh Tribedi E-mail: lokesh@tifr.res.in;
Dr. Deepankar Misra E-mail: dmisra@tifr.res.in
URL: http://www.tifr.res.in/~abap
Ph.D positions available
Nano-optics and Mesoscopic Optics Laboratory
Research Interests:
We study the transport of optical waves through media which have a variation in the
refractive index over length‐scales comparable to the wavelength. These experiments
deal with visible or near‐infrared radiation. The structure can be ordered, disordered or
even a combination of both. Given that light can experience amplification and nonlinear
effects, fascinating phenomena, hitherto unpredicted by theory, are unravelled in these
systems. Sophisticated laser sources, ultrasensitive detectors, and nanofabrication
techniques makes it possible to observe even the most elusive of phenomena!
Anderson localization: A most exotic optical
phenomenon, realized by disorder-induced
interferences, directly observed in the lab.
Anderson-localized mode (exponentially decaying
wings) in an array of amplifying microresonators.
Facilities and Equipments:
Schematic of a near-field measurement.
The lab is equipped with several laser sources,
sensitive spectral and temporal detectors at
various wavelengths , sample making facilities
etc. Thin metal-film plasmonic media are
fabricated inhouse, while nanostructured lowdimensional semiconductor membranes are
obtained from collaborators. Sub-wavelength
topographic and optical measurements can be
made using an indigenous near-field scanning
optical microscope.
Recent Results:
Exponentially‐tempered Levy sums, Phys.
Rev. Lett., (2015)
Super‐critical angle fluorescence, App. Opt.,
(2015)
Super‐reflection from a random laser, Phys.
Rev. A (2014)
Gap‐state random lasing, Phys. Rev. Lett.,
(2013)
Simultaneous topographic and
near-field optical measurement of a
plasmonic
nanowire,
showing
decaying fronts of intensity.
Current Members:
Sushil Mujumdar,
Randhir Kumar, Tajinder Singh, Shadak Alee, Arpit
Rawankar, Sreeman Kumar.
Location and Contact Details:
Room AB101 (Lab) - Extn 2195.
Room P109 (Prof. Sushil Mujumdar) - Extn 2459
Prof. Sushil Mujumdar Email: mujumdar@tifr.res.in
URL: http://www.tifr.res.in/~mujumdar
Ph.D positions available
Nuclear Physics Laboratory
Research Interests:
Search for Neutrinoless Double Beta Decay (0νββ):
The mass and nature of neutrinos play an important role in theories beyond the
standard model. Presently, 0νββ, which can
occur if neutrinos have mass and are their own
antiparticles, is perhaps the only experiment
that can tell us whether the neutrino is a Dirac
or a Majorana particle. Further, 0νββ can
provide the information on absolute effective
mass of the neutrinos. In India, a feasibility
study to search for 0νββ in 124Sn has been
initiated. The TIN.TIN experiment (The INdia’s
TIN detector) will be housed at The India-based
http://www.tifr.res.in/~tin.tin Neutrino Observatory (INO), an underground
facility with
~1000 m rock cover all around.
124
Development of cryogenic bolometer of Sn operating around 10 mK is in progress
Nuclear structure studies with GDR:
The Giant Dipole Resonance (GDR) gamma rays
provide a very unique probe to study structure of
excited nuclei at high angular momentum. Study of
the shape evolution of nuclei with angular momentum
in A~160 region, has been the main focus in recent
years. The group is actively engaged in the
development of a novel detector array comprising
LaBr3(Ce)+ NaI Phoswich as a part of PARIS (Photon
Array for studies with Radioactive Ion and Stable
beams) collaboration, for studying GDR in highly
Energy spectra with 241Am-9Be
unstable nuclei.
source with PARIS prototype
detector
Reactions with Weakly Bound nuclei:
Reactions with weakly bound stable and unstable nuclei provide opportunities to
explore unusual features of nuclei like halo/skin structures, extended shapes and large
breakup probabilities. We study this with experiments using stable beams like 6,7Li at
PLF, Mumbai and using Radioactive ion beams like 6,8He at GANIL (France).
Current Members:
V. Nanal, R.G. Pillay
Chandan Ghosh, Abhijit Garai, Harisree, Ghanshyam Gupta
and Balaram Dey
Location and Contact Details:
Room P106 (Lab) - Extn: 2511/2333
Prof. V. Nanal Email: nanal@tifr.res.in
Prof. R. G. Pillay Email: pillay@tifr.res.in
Ph.D positions available
Theoretical Physics
Research Interests:
The theoretical physics program focuses on the development of fundamental and
phenomenological models to identify various new phases of dense nuclear matter with
an emphasis to study the:(i) Equation of state of neutron-rich asymmetric nuclear
matter formed at intermediate energy heavy ion collisions,(ii) Properties of the novel
state of matter viz. the Quark-Gluon Plasma formed at ultra-relativistic energy heavy ion
collisions at RHIC/BNL and LHC/CERN.
Density dependence of symmetry energy:
The density dependence of asymmetry energy has wide-ranging implications for the
physics with radioactive ion beams to neutron stars. However, it is poorly known. Our
group has developed relativistic mean-field and transport models that could constrain
the asymmetry energy over wide density range by comparison with measurements of:
neutron skin of various nuclei at subsaturation nuclear densities and mass-radius of
neutrons stars at supranormal densities.
The Quark-Gluon Plasma:
In ultra-relativistic heavy-ion collisions high temperature and density are reached. The
quarks and gluons confined within the atomic nuclei are liberated to form the QuarkGluon Plasma (QGP). Our group has developed very sophisticated transport models that
encompasses all stages of the collision. Within this model, we have shown that the QGP
formed at RHIC and LHC is a (strongly coupled) near perfect fluid that has large
anisotropic collective flow and long range dihadron correlations. We have also
formulated relativistic dissipative fluid dynamics from kinetic theory which could explain
the observed femtoscopic radii of emerging particles from QGP.
Nuclear Matter Phase diagram
Current Members:
Subrata Pal,
Sreemoyee Sarkar,
Ananta Mishra,
Chandrodoy Chattopadhyay
Room P309 (Prof. Subrata Pal) – Extn 2820
Prof. Subrata Pal Email: spal@tifr.res.in
Ph.D positions available
Discrete Gamma Spectroscopy of Atomic Nuclei
Research Interests:
We investigate the low energy response of atomic nuclei to rotational stress using a powerful
“femtoscope‘’ consisting of segmented high purity Germanium detectors. The nuclei are
prepared in excited states (with 1021 rotations per second) using energetic beams from the
heavy ion accelerators. The fast rotating nucleus decays to its ground state, through the
intermediate excited states, emitting copious gamma rays that are measured by the
femtoscope. By casting the nuclei to various shapes and studying their decays, the emergent
properties of complex nuclear many-body system are elucidated.
The Quest
How does a simple pattern emerge in excitation of complex nuclei?
How are the patterns of the excited states related with symmetry and shape of nuclei?
What are the different correlations present in the nuclei?
Facilities and Equipments:
Members in the group are involved in the
simulation, design and testing of state-of-the-art
radiation detectors required for the investigation
of nuclear structure. The young investigators in the
group get the opportunities to work on advanced
digital signal processing scheme and data analysis.
Current Members:
Rudrajyoti Palit
B.S. Naidu, R. Donthi, S. Jadhav, S. Saha, J.
Sethi, S. Biswas, D. Choudhury, P. Singh
Location and Contact Details:
Room: P309 (Prof. Rudrajyoti Palit) – Extn 2562
URL: http://www.tifr.res.in/~nsg
PhD positions available
Facilities
The Pelletron LINAC facility, a joint venture of
TIFR and BARC, has been a major research centre
for the heavy ion accelerator based research in
India. The Pelletron accelerator was inaugurated
on 30th December 1988 and marked an
important milestone in nuclear physics research
in India. The facility was augmented in July 2007
with
the
indigenously
developed
superconducting LINAC booster to enhance the
energy of the accelerated beams. A number of
state-of-the-art experimental facilities have been
developed at this centre to pursue frontier
research in nuclear, atomic, condensed matter
and bio-environmental physics.
Joint TIFR-BARC Facility
http://www.tifr.res.in/~pell
Experiment hall
LINAC hall