A pioneering effort

Published : Sep 26, 2003 00:00 IST

Scientific research and industry will benefit substantially from the commissioning of Indus-2, a synchrotron radiation source of the Centre for Advanced Technology, next year.

THE Centre for Advanced Technology (CAT), Indore, Madhya Pradesh, which works in frontline areas such as accelerators, lasers, super-conducting magnets, crystals, laser fusion and cryogenics, will reach a milestone when Indus-2, a synchrotron radiation source, is commissioned by April 2004. Indus-1 has been operational since April 1999. Dr. D.D. Bhawalkar, Director, CAT, said: "Large accelerators are among the most complex machines. Synchrotron radiation is the fastest growing research area in the world because it has applications in every field of science, engineering and technology." A few months ago, CAT commissioned another industrial accelerator.

Work is under way in a massive, circular building on the integration of thousands of components of Indus-2, a huge accelerator. It will emit synchrotron radiation, which has applications in the pharmaceutical industry (in designing drugs by studying the molecular structure of proteins); in the petrochemical industry; in studying defects in exotic alloys; in imaging organs for treating kidney ailments and breast cancer; in angiography; in lithography; in photo-physics; in micro-mechanics, and so forth.

CAT is a premier centre of the Department of Atomic Energy (DAE). Bhawalkar says: "We work on diverse advanced technologies which are not available easily elsewhere." For instance, CAT's Laser Division has developed a variety of lasers that have applications in cutting sheet metal with precision; in performing remote and blind operations in inaccessible, radioactive parts of nuclear reactors; in cutting nuclear fuel bundles; in wielding titanium shells of pacemakers; in performing external surgical operations; in treating cancer and tuberculosis; and in monitoring pollution. A medical nitrogen laser, developed in CAT, is used at the Choithram Hospital and Research Centre in Indore for treating patients with tuberculosis and burns. Surgical carbon dioxide laser systems developed and produced at CAT are used in hospitals across the country, including the All India Institute of Medical Sciences, New Delhi, in non-invasive operations in the ear, the nose and the throat; in dermatology; in gynaecology and in oncology.

Attention is now on Indus-2, which is a fully indigenous effort. Dr. Anil Kakodkar, Chairman, Atomic Energy Commission, and Secretary, DAE, told Frontline: "We shall fully assemble Indus-2 by the end of 2003 and get into the commissioning mode by early 2004." With its commissioning, India will be one of the handful of countries to have built such accelerators. Indus-2 will cost Rs.92 crores - a fraction of what it would cost to build such an accelerator in the West. Bhawalkar said: "We are building everything from scratch, and indigenously too. A few countries such as Taiwan and South Korea obtained the designs and components from the United States."

CAT was established in 1987. In the late 1970s, it was felt that there was the necessity to establish a national centre for research and development (R & D) in high-technology areas such as accelerators, high-power lasers and laser fusion. So the DAE appointed a committee in 1979 under the chairmanship of Dr. P.K. Iyengar, the then Director, Physics Group, Bhabha Atomic Research Centre (BARC), to frame a long-term programme for the construction of accelerators in India. Towards the end of 1981, the Central government approved the DAE's proposal. Prime Minister Indira Gandhi, who held the portfolio of Atomic Energy, wanted the centre to come up in Bihar, Orissa or Madhya Pradesh. Hence Indore was selected.

The site housing the centre on the outskirts of Indore, was selected by Bhawalkar and approved by the site selection committee chaired by Dr. Raja Ramanna, the then Secretary, DAE. At that time it was a vast grassland with a lake. On the edge of the lake stood the Sukhniwas Palace, built 109 years ago as the weekend resort of the Holkars, the maharajas of Indore. There was only one road leading to the palace, and it did not go further. Indira Gandhi approved the site in 1983. President Zail Singh inaugurated the construction work in February 1984. Sukhniwas Palace housed the office of the Director until about a year ago. Bhawalkar was appointed the first Director, in March 1987, and he continues to hold the post.

The complex today is spread over 1,700 acres (680 hectares) and has scores of massive buildings that house accelerators, laser laboratories, workshops, a library, a computer centre and so on and an auditorium, a fire-station, houses for the staff, schools and a sports complex.

The development of accelerators for research in basic nuclear physics started in India prior to the 1950s. Prof. Meghnad Saha developed a cyclotron in 1940 at the Institute of Nuclear Physics, Kolkata (the present Saha Institute of Nuclear Physics). Accelerator development technology came into its own in India when an indigenously developed and built Variable Energy Cyclotron was commissioned in 1978 at the Variable Energy Cyclotron Centre at Kolkata. Under CAT's accelerator programme came up Indus-1, India's first synchrotron radiation source (SRS).

Accelerators are huge machines that given energy to charged particles such as electrons, protons, ions and so on. They were originally developed to study the finer structure of an atom, that is, to investigate its constituents. An atom comprises electrons, protons and neutrons. By accelerating electrons and neutrons to very high energies and smashing them into targets, or into each other, physicists try to understand the structure of matter. They thus try to unravel the forces acting between them. These energies are measured in terms of electron volts (eV). For instance, in Indus-1, electrons are accelerated to an energy of 450 MeV (million electron volts). In Indus-2, electrons are accelerated to 2,500 MeV, that is, 2.5 giga eV. The higher the energy of the particles, the smaller the size of matter that can be studied.

Smaller accelerators are increasingly used in medicine and industry. In medicine, their use is very similar to that of the familiar X-ray machine (which is also a particle accelerator in which electrons are accelerated and made to strike a target to produce X-rays). The use of heavy energy particles has proved effective in treating cancer. Accelerators are used in industry for the treatment of materials, and in wielding, drilling, and in the etching of microchips in the production of integrated circuits. The largest accelerator under construction is at The European Laboratory for Practical Physics (CERN) and is called the Large Hadron Collider (LHC). It is in the form of a circle with a perimeter of 27 km and can accelerate two protons beams travelling in opposite directions to energy levels of 7 MeV. These beams are then made to collide.

Accelerators come in two types, circular and linear. Both Indus-1 and 2 belong to the former. Accelerators use powerful electric fields to push energy into a beam of particles. Magnetic fields are used to keep the beam tightly focussed. In circular accelerators, the magnetic field makes the electron move in a circular orbit and emit radiation called synchrotron radiation. At low electron velocities, this radiation spreads out in all directions, like light from a candle. But when the velocity reaches close to that of light (called relativistic velocity), the radiation gets focussed in a narrow cone which has an angle typically of only one-hundredth of a degree. So its intensity is very high. This radiation contains infra-red, visible light, ultraviolet, X-rays and hard X-rays. So it is a versatile source of electro-magnetic radiation. Indus-1 emits all these except X-rays and hard X-rays. Indus-2 will emit X-rays and hard X-rays as well. These X-rays will be a million times more intense than those from laboratory sources.

According to R.V. Nandedkar, Head of the Synchrotron Utilisation Programme at CAT, synchrotron radiation has emerged as a powerful tool for pure and applied research for state-of-the-art investigation in almost all branches of science because of its unique properties such as broad spectrum (from far infra-red to hard X-rays), small beam size, and short pulse duration. When CAT was established, a policy decision was taken that all the technologies for its accelerator programme should be developed indigenously. Nandedkar said: "We developed all the technologies to build Indus-1 on our own. The magnets are made here. Every component was designed and fabricated in-house at CAT. So it took a comparatively long time. But we learnt the technology for Indus-2 and we are building it fast." Less than 1 per cent of the components of Indus-2 are imported (in terms of value).

The biggest challenge faced by CAT while constructing Indus-1 was that none of the people involved had ever worked on a synchrotron earlier. It took them a lot of effort and time to acquire the required knowledge and expertise. Bhawalkar nostaligically said: "The construction of Indus-1 by this group of people is itself a success story." CAT now has in-house facilities in advanced technologies such as ultra high vacuum chambers, magnets and control electronics. Indus-1 has three beam lines that are operational now. They are being used to conduct different experiments such as reflectivity, photo-electron spectroscopy and photophysics. Nandedkar said: "These studies have immense importance in the study of surfaces, multi-layers and physics of materials. They have relevance in the study of semi-conductors and super-conductors." The beam lines were developed by CAT, BARC and the Inter-University Consortium.

The building where Indus-2 is assembled is a circular structure with a diameter of 130 metres. It has a 1.2 metre-thick circular wall to shield X-Rays. There are holes in the wall through which synchrotron radiation will pass. The inner circular wall is 60 cm thick. In between these two walls, huge magnets will be positioned and aligned to a precision of one-tenth of a millimetre. They are positioned according to references in the walls. Even the crane inside the building has to run in a circular track. There are big iron girders on top.

Indus-2 will have a wider range of applications than Indus-1 because it will also emit X-rays and the intensity of its photon beam is very high, according to Gurnam Singh, head of the Beam Dynamics Division. Its hard X-ray region will have important applications in industry. It will be used in protein crystallography for studying the molecular structure of proteins. This will have applications in designing drugs. Another beam line of Indus-2 will have applications in catalysis, petro-chemical industries and so forth. A third beam line will be used to study defects in metals, exotic alloys, diamonds and graphite, and impurities in semi-conducting materials.

CAT is also developing a multi-model accelerator-based radiotherapy machine for the treatment of cancer. The country needs about 1,000 radiotherapy machines, but there are only 250 available now.

The accelerators at CAT are also being used to produce electron beams for irradiating onions, potatoes and spices to prevent them from sprouting.

In the research and development of lasers, CAT has set new standards. Lasers are tools of unprecedented power and precision. They have applications in industry, medicine and entertainment. A laser is basically a very intense beam of light. With their intensity, lasers can melt, burn or evaporate materials. Thus they are used in cutting, welding, drilling, soldering, and cladding metals. Lasers can be used in processing ceramics and glass without breaking them. Even the hardest material, diamond, can be easily cut with a laser, obviating the necessity to use expensive cutting tools. Lasers are used in the electronics industry to trim resistors. They are also used in scribing and making emblems. Laser beams are of different types - some are visible and some are not. Most of the industrial high-power lasers are infra-red and not visible.

According to T.P.S. Nathan, the head of the Solid State Laser Division, the division has developed three types of lasers: carbon dioxide laser emitting infra-red light for performing surgical procedures; Nd-YAG solid state laser which is also infra red; and diode pumped solid state lasers. The division has developed many pieces of laser-based welding and cutting equipment for use in the nuclear industry. They are used in cutting nuclear fuel bundles and radioactive waste components, and welding radioactive capsules. CAT lasers were used in cutting metal flow tubes, which got fused together in a reactor at the Kakrapar Atomic Power Station in Gujarat. Thus, it is also an excellent tool for remote operations in radioactive environments. Nathan said: "This division was established to prove the techno-economic viability of making lasers available for a variety of applications. We make the equipment for producing lasers at a cost 15 to 55 per cent lower than others, without sacrificing quality and technical specifications."

CARBON dioxide lasers developed at CAT are used for performing external surgeries in the ear, the nose and the throat; and in gynaecology; dermatology; oncology, and so on. Laser surgery is a bloodless procedure and hence the chances of infection are less. Patients suffer less pain, and healing is fast. Thus, lasers have become popular tools for surgery. CAT has supplied 15 lasers to hospitals from Guwahati To Thiruvananthapuram.

Bhawalkar and Nathan narrated how the Nd-YAG laser developed by CAT helped an Indian company to cut down drastically costs incurred in welding cardiac pacemakers. This company, in Indore, used to send assembled pacemakers, made by them, to the United States for welding. These pacemakers are made of two titanium shells of 0.5 mm thickness. There are small electronic circuits inside them, which transmit pulses to the heart, so that it starts beating in a rhythmic manner. After the electronic circuits are kept inside, the shells of the box should be welded. The heat applied should be very low and the box completely leak-proof. Conventional welding techniques cannot be used because the electronic circuits will be destroyed. The company wanted to import a laser welding unit to do it in-house. But the cost was prohibitive, at Rs.54 lakhs. With a 100 per cent duty, it rose to Rs.1.08 crores. The company approached CAT, which developed an automatic four-axis laser-welding machine, which cost only Rs.11.5 lakhs.

Vinod K. Wadhawan, head of the Laser Materials Division, said a research group at CAT had developed a portable flourimeter to diagnose cancers of the oral cavity, the breast and the cervix, using nitrogen-based lasers.

An important application of nitrogen laser, according to Bhawalkar is to diagnose cancer early using fluorescence. The tissues are illuminated by using a flourimeter. The difference in the spectrum between a normal cell and a cancerous cell can be detected.

Another application is in treating tuberculosis cases that are resistant to drugs. After the location of the tuberculosis is identified in such cases, the laser light is used to stimulate the defence mechanism so that the infection responds to treatment with drugs.

In the Industrial Lasers Division, it was fascinating to see carbon dioxide industrial lasers burn bricks at 3,0000 C or drill a hole right through a 6.2-inch thick concrete block. Another machine was being used for cladding at 1,500 to 2,0000 C.

Lasers are also used to do aesthetic etching and profile cutting and to drill holes in wood. Thus, there were different carbon dioxide lasers with varied power ratings. A.K. Nath, the head of the Industrial Lasers Division said: "We have many types of industrial lasers. They are totally indigenous. Our engineers designed and developed them."

CAT won the admiration of the scientific community the world over when it was asked to supply 2,000 superconducting magnets to CERN's LHC, which is under construction now. Under a protocol signed between the DAE and CERN on March 29, 1996, India is to participate in the construction of the LHC. The DAE is to contribute 1 per cent in kind to the LHC. Bhawalkar is the coordinator of this project, and CAT is the nodal agency.

The Superconducing Magnets Laboratory is working hard to send more than 30 magnets every month to CERN.

Path-breaking work has been done at the Crystals Division where crystals of remarkably clarity are grown. Crystals have applications in defence, industry, fusion research, and so on. During the Second World War, they were used in sonars.

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