A Brief update on INO feasibility project: M.V.N.Murthy, IMSc ------------------------------------------------------------- As a result of the support we have received from the Institutes, Community and the funding agency-Department of Atomic Energy, a National Neutrino Collaboration (NNC), of which you are a member, has now been established to build an India-based Neutrino Observatory (INO). The collaboration is now assigned the task of doing the feasibility studies for which the Department of Atomic Energy has provided adequate financial asssistance in its tenth plan outlay. A memorandum of understanding (MOU) was signed by the directors of TIFR, BARC, IMSc, SINP, VECC, HRI and IOP on August 30th 2002 to enable a smooth functioning of the NNC during the feasibility period which is expected to be two years. The NNC has been assigned the goal of creating an underground neutrino laboratory with the long term goal of conducting decisive experiments in neutrino physics as also other experiments which require such a unique facility. After much discussion, it has been decided to start with a magnetised Iron Calorimeter (ICAL) as the detector, although other types of detector development will be taken up at a later stage. A suitable location for this detector (and any future ones) is also being studied with the help of the Geological Survey of India. Initially the detector may have two modules each measuring approximately 15m x 15m x 13m (height) built using of 6cm thick magnetised iron plates which together weigh about 32 ktons. Depending on the physics needs and goals, the number of modules may be increased. The initial Laboratory Cavern design will incorporate this need. Most likely, the radically new concept of Resistive Place Chamber(RPC) detector wafers with fast timing (1 nanosecond) will be sandwiched between the iron plates. Because of the magnetic field the detector will provide charge identification, which is not possible at present in any of the existing detectors (other than the soon-to-be-ready MINOS). ICAL will be in a position to clinch the evidence for oscillation. For this it is necessary to see a length-dependent depletion pattern of a particular flavour of neutrino (periodic oscillatory behaviour). So far, only length-averaged depletion of neutrino fluxes have been observed. A clear oscillation pattern should be established to ensure that it is oscillations that are responsible for the observed effects. It may also be advantageous to study the depletion of a neutrino flavour and the simultaneous enhancement of another flavour; the ICAL may not be able to do this without some more modifications; this possibility should certainly be studied in the long term as well. ICAL should be able to study the spectra of muons from the atmospheric neutrinos and establish this "trough and peak" effect. Apart from this ICAL will also provide a far detector for the up-coming neutrino factories with the longest baseline. Charged identification that is built into ICAL will be crucial for the long base line experiments. Because of the geographical location of India, it is possible to find sites that are close to the equator. Placing a solar neutrino detector at such a site will have the advantage of seeing earth core matter effects, that all other current detectors are only very marginally (few percents) sensitive to. At present the NNC is divided into four main working groups: (1) Site Survey, (2) Magnet and Detector design, (3) Simulations, (4) Data acquisition systems. Site Survey: We have found two very good sites for locating the underground laboratory: The first one is located on the Northern slopes of Nilgiris close to the Cosmic Ray and Radio Astronomy labs in Ooty. The second one is at a place called Rammam in the Darjeeling district. In both places adequate rock cover, comparable to other labs around the world, exists. Detailed surveys are being done with the help of Geological Survey of India, and the respective Electricity Boards in Tamil Nadu and West Bengal who have already an established presence in these two sites. We are in the process of preparing reports on these sites giving a detailed comparison. Magnet and detector design: The detector group is engaged in designing a prototype which will be scaled up once the concept is established. Smaller prototypes have been designed and are being checked for their efficiency. Magnet design is yet another area where lot of work will be required given the size of ICAL. A promising beginning has been made but the new concepts that are being developed here need to be demonstrated further. Simulations: The simulation group has written a program compatible with the CERN library GEANT code that models the ICAL detector geometry. A magnetic field has also been incorporated into the code. A code that acts as a neutrino event generator has been obtained. The output of the generator has been made compatible to be read by the GEANT code. Some basic physics issues have been addressed. Code-correction is now complete and now the physics simulation will begin. Simultaneously, questions about track recognition and fitting (needed to analyse the generated events) are now being addressed. Data acquisition and electronics: The Data acquisition systems and the electronics are being looked into by yet another group. Given the accumulated experience in working with other labs around the world, there should not be any major problem here except in the matter of scaling up to huge numbers that will be required for ICAL. There are several questions that still need to be addressed, such as the availability at a reasonable cost of the amount of iron required for the detector, the structural stability and many other engineering questions. The NNC is yet to look into these questions but hopefully will be in a position to answer these questions soon. The effort of building an underground laboratory requires the support of all the members of the collaboration. The list of tasks are given below. Members of the collaboration may decide the area/s in which they can substantially contribute. We urge all to take an active role in making this venture a success. Especially, the time element has become very crucial because of increasing activity in the field; in order to be competetive, we should be quick ! A website http://www.imsc.res.in/~ino is underconstruction. It will be periodically updated. Collaboration members are welcome to go through the website and give their suggestions. Some areas of the web-site (containing details of the sub-group activities) are restricted. If you are interested in reading these pages, please write to murthy@imsc.res.in for the pass-word. The lab has been conceived on a scale that has not been attempted in the country until now. It is also a new model of inter institutional collaboration. Human resources needed for the project is also huge. Many members of the collaboration are already engaged in contacting Universities and other institutions in India to enthuse students and other research workers to join in this effort when the goal of creating the underground lab comes into fruition. It is likely that activities and interest in neutrino physics will only increase over the next few decades; hence any vision of a venture such as INO must be a long-term one. We need more people to sustain our enthusiasm and do more among our students in order to maximise the effort that goes into building this laboratory.