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Centre for Astroparticle Physics and Space Sciences – A National Facility at Bose Institute ( A project under IRHPA Scheme ) Sibaji Raha Bose Institute Kolkata. Acharya J.C. Bose (1858 – 1937).
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Centre for Astroparticle Physics and Space Sciences – A National Facility at Bose Institute (A project under IRHPA Scheme) Sibaji Raha Bose Institute Kolkata
“India is drawn into the vortex of international competition. She has to become efficient in every way – through spread of education, through performance of civic duties and responsibilities, through activities both industrial and commercial. Neglect of these essentials of national duty will imperil her very existence.”– Acharya J.C.Bose
Origin • In-house expertise : Need for consolidation • Darjeeling Campus : Location & Opportunities (a) Cosmic Ray (b) Atmospheric Chemistry (c) Radiometric studies
Four major programmes 1. Cosmic ray studies at high altitude 2. Changing airspace environment in Eastern Himalayas 3. Children’s science resource centre 4. Manpower development – training programmes
Electrons – electric cherge - EM force – Photon Quarks - Colour Charge - Strong force – Gluon
Quark – three colours - Red , Blue , Green Gluons – eight - red + anti-blue and other combinations Mesons – quark+antiquark – colour+anticolour – WHITE Baryons – three quarks – red+blue+green - WHITE
H- matter P.T. Q – matter SQM Ground state of matter First idea : Bodmer (1971) Resurrected : Witten (1984) Stable SQM : Conflict with experience ???? 2-flavour energy > 3-flavour Lowering due to extra Fermi well Stable QM 3-flavour matter Stable SQM significant amount s quarks For nuclei high order of weak interaction to convert u & d to s
SQM & Strangelet Search : • SQM : • Early universe quark-hadron phase transition • Quark nugget MACHO • 2. Compact stars (Core of Neutron Stars or Quark Stars) • Strangelets : • Heavy Ion Collision • Short time • Much smaller size A ~ 10-20 • Stability Problem at high temperature • 2. Cosmic Ray events : • Collision of Strange stars or other strange objects Shower
Detection of strangelets Propagation mechanism of strangelets How far can it travel through atmosphere How does it interact with atmosphere ? Important observations Stability of strange matter Small positive charge massive s quark Z/A 1
Remarks : Detection of strangelets : Passive detectors Active detectors : Air shower studies in collaboration
Study of Changing airspace environment in Eastern Himalayas
Indo-Gangetic plane : Agricultural as well as Industrial activity Source of atmospheric pollutants Vulnerable place from changing environment • Himalaya is subject to (a) emissions from IGP regions (b) pollutants transported from long distances • Himalaya : Unique place to monitor airspace environment
Eastern Himalaya : wet with rich forest cover and lesser population Western Himalaya : dry, scanty forest cover and high population Monitoring stations : Mostly in western Himalaya
Eastern Himalaya Monitoring stations Pyramid Station 5034 meters Sandakphu 4200 meters Kathmandu ICIMOD-UCSD Station Darjeeling 2500 meters North Bengal University, Siliguri
Physical Environment Chemical Environment Monitoring of trans-boundary pollutants H2O: mm waves O3, CO, NOx, SO2: Trace Species Aerosols: Scattering/ Absorbing Met Data 3-D Trajectories Eastern Himalayas 23.8 GHz (Water Vapour) 31.4 GHz (Liquid Water) Distrometers (DSD) Radio Environment Emission Inventories Air Pollutant Dispersal 3-D Chemical Modeling Chemical, Physical, and Radio Mapping of the region
Workshops and summer schools on various aspects of the : cosmic ray physics Instrumentation Environmental science Weather modeling studies Numerical simulation with hands-on training Aimed at : Masters level and beginning doctoral students
Active detectors : Air shower studies What are Cosmic Rays?? • “Cosmic Rays” = subatomic particles • Cosmic Rays= unknown origin ( Some clue – Image of supernova debris-Nature’04) • Composed of various types of particle: • Primary Cosmic Rays • Hydrogen nuclei (87%) • Helium nuclei (12%) – “alpha particle” • Nuclei from heavier elements • High speed electrons – “beta particles” • Secondary Cosmic Rays • Particles slam into gas atoms in upper atmosphere • Fragments shower down and/or disintegrate: • pions muons + neutrinos pion electron + positron + gamma rays • Muon and neurtrinos make it to the surface of the earth
Climate and Sun relationship * First suggested by William Herschel 1801 : variation in solar irradiance ► climate change on earth variation of British wheat prices with sunspot numbers (sunspot ► a region on the sun’s surface, marked by lower temperature ) * Little ice age : 1645 – 1715 Maunder Sunspot minimum * Correlation between solar cycle variations and tropical sea-surface temperature * Direct Link ► 1979-1990 cycle irradiance variation ~ 0.1% too small for direct effect
● Indirect Link Likely ● Solar radiation input in the lower atmosphere and cloudiness Effect of Cloud : a) cooling by reflecting solar radiation b) warm the climate by trapping radiation emitted from earth’s surface ● Cosmic ray particle : carriers of variability to the lower atmosphere ● Variation of cosmic ray on solar phenomena An Example : Observation during solar eclipse of October 24, 1995
● Total solar eclipse : period of totality 1 min 7sec. ● variation of γ rays in the range 0.3 – 3 MeV ● Cosmic ray component : Figure
● Other effects 1. Cosmic ray intensity sunspot cycle 11 year cycle 2. Forbush Decrease : sudden decrease in cosmic ray in intensity followed by gradual recovery during several days – weeks • Interplanetary shocks passing through earth’s orbit produce an effective barrier • shock occurs following solar coronal mass ejection Mass ejection may occur in the absence of solar flare
Cosmic ray – climate Cosmic ray – sunspot cycle – global cloud cover 11 year cycle
Cosmic ray – climate contd. …. Absolute % variation of global cloud cover observed by Satellites and relative % variation of cosmic ray flux
Cosmic ray – climate contd. …. • Observation of 30% fall in rainfall on the initial day of the Forbush decrease • Forbush decrease – decrease of cloudiness time scale days
Convection (also called "free convection" or "buoyant lifting"):
Topographic (also called "orographic lifting" or "forced lifting"):
Frontal lifting: Blue: Cold air ; Red: Hot air Blue: Cold air Red: Hot air
A cloud is composed of millions of little droplets of water (or ice crytals when temperature is very low) suspended in the air. Hence a cloud can form when water vapor becomes liquid, i.e. when the humid air is cooled and condenses on tiny particles.
Cosmic Ray – Cloud formation 1. Enhanced aerosol nucleation and growth into cloud condensation nuclei
Cosmic Ray-Cloud Contd. …. • Enhanced CCN activation by charge attachment ▪ Aerosol activation rapid growth of an aerosol into large droplet ▪ Aerosol charging by cosmic ionization Decrease the supersaturation • Increase in droplet number Cloud microphysics
Cosmic Ray-Cloud Contd. …. 3. Ions and radicals may promote the formation of condensable vapours or enhance the condensation of vapours already present.
Cosmic Ray-Cloud Contd. …. 4. Creation of ice nuclei
Cosmic Ray-Cloud Contd. …. 5. Effect of cosmic ray on stratospheric clouds and ozone depletion (Previous processes occur in the troposphere)
Experiments andobservations Cloud cover observation : satellite and ground based observations Cosmic ray flux measurement CERN : link between cosmic ray and cloud CERN Proton synchrotron Adjustable cosmic ray source CLOUD Project Based on cloud chamber that is designed to duplicate the conditions prevailing in the atmosphere.
GRAPES III Experiment (Gamma Ray Astronomy at PeV(1015eV) Energies III) Ooty, Tamil Nadu 288 scintillation detector – to detect ray component of cosmic ray 3700 Proportional counters – to detect muon component Large area muon detector – can be used for observation on muons produced by lower energy protons affected by solar phenomena e.g. solar flares & coronal mass ejection Useful for space weather forecasting
Our Goal To understand the physics of Solar activity (SF & CME) Cosmic ray flux (FD) Cloud formation
COMMITTEE FOR DAE-DST VISION FOR DRAWING UP A ROADMAP FOR HIGH ENERGY AND NUCLEAR PHYSICS RESEARCH. 3 major areas : Particle Physics, Nuclear Physics & Astroparticle Physics. Major recommendations: In all three fields, particle physics, nuclear physics and astro-particle physics, • Indian groups are continuing to do commendable work and are internationally well recognized. • In all these fields there are a sufficient number of exciting future programs in which Indian groups can participate, both in the domestic scene as well as within the International context. • The topmost priority in all fields would be to continue and complete the ongoing projects, which are already funded, successfully.
Astro-particle physics: • currently ongoing programmes are: • GRAPES (TIFR) at Ooty: an ongoing TIFR experiment to determine primary composition of UHE (Ultra High Energy) cosmic ray flux over the energy range 30 TeV – 30,000 PeV. Goals are to provide insight into acceleration mechanisms of cosmic rays as well as to study particle interactions in the very forward fragmentation region. There is also a plan to install mini-GRAPES arrays at several universities in the country. Cosmic Ray studies (CORAL) using the TPC of the ALICE detector at CERN complements the studies with GRAPES.
An already funded program (by DAE till 2012) is the Cherenkov array MACE at the Himalayan Gamma Ray Observatory (HiGRO of BARC-TIFR-IIA) near Hanle, with a very high resolution imaging camera, during 2007-12, next to the Himalayan Chandra Optical Telescope. Later expansion is planned for setting up a total of 16 element array by around 2018. • Search for Strangelets in Cosmic Rays. A large array of solid state detectors is being installed at Sandakphu at 4200 metres altitude. This project is already funded by DST during the 2005-10 period. The group plans to expand the array during 2010-16.
Future programs to be supported (in order of priority): • Expansion of GRAPES • Expansion of the MACE telescope array at HiGRO by 2018 • Expansion of Passive detector array, if needed