THE Indian contribution to the accelerator included provision of some key subsystems and testing. The most important among these are the precise magnet positioning system (PMPS) jacks for all the cryomagnets that guide the beam trajectory and the superconducting corrector magnets – the sextupoles, octupoles and decapoles. The PMPS jacks are particularly critical to ensure trajectory accuracy. The dipole magnet assemblies, which are more than 15 metre long and weigh more than 32 tonnes, need to be positioned using these jacks.

The additional skilled manpower contribution was in terms of technical personnel for making all the superconducting magnet measurements at CERN. This machine-related work was carried out by different units of the Department of Atomic Energy with the Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, as the nodal centre.

India has also made significant contribution to the detectors of the two experiments in which its physicists are participating: Compact Muon Solenoid (CMS) and A Large Ion Collider (ALICE). The Tata Institute of Fundamental Research (TIFR), Mumbai, was responsible for coordinating the Indian contribution to the CMS detector and the Variable Energy Cyclotron Centre (VECC), Kolkata, for the contribution to the ALICE detector.

For the CMS, the contribution included silicon detectors, pre-shower electronics and devices for measuring energies of particles produced called the outer hadron calorimeter and the electromagnetic calorimeter.

For ALICE, India provided the photon multiplicity detector in its entirety and components of the muon chamber arm. The highlight of the contribution to the muon arm is the design of an ASIC chip called MANAS by the VECC, which was fabricated by the Semiconductor Complex Ltd. (SCL), Chandigarh. India has supplied 100,000 MANAS chips for the 1.6 million channels in the muon arm.

India has also made significant contribution to the World LHC Computing Grid in terms of grid software, which includes development of problem tracking software and middleware for the grid operation equivalent to about 50 man-years of developmental effort.

R. Ramachandran