- Published by the
- Department of Atomic Energy
- Government of India
- VOL. 35/NO.5-6/Nov.-Dec. 2001
Electronics Corporation of India Ltd. (ECIL) Develops Conveyorised Parcel Viewer System
The Conveyorised Parcel Viewer developed by ECIL, a public sector undertaking of DAE is similar in concept to the X-ray baggage inspection systems installed in the country at the airports. This system is compact and can be moved and set up anywhere. It is ideal for inspection of concealed parcels or packages and detection of concealed weapons, fire arms or other such prohibited items without opening them. It is specially useful in high risk locations such as post offices, ministerial buildings, secretariats, VIP-offices, embassy-offices and other places where sealed packages are handled and have high security risks. The present security environment across the world very much needs equipment to help the security agencies to forewarn such kind of threats. Mail containing powdery substances, also be detected by the use of this machine. The envelope containing powdery substance can be put through this machine. The image will indicate the presence of powdery substance inside the envelope, if it is present.
ECIL is planning to produce this machine in large numbers to meet the immediate security needs of the country. Exporting of these machines is also planned.
" The excellent performance in our power programme was matched by excellent performance in fuel manufacture and heavy water production....."
[Excerpts from the Address by Dr. Anil Kakodkar, Chairman, Atomic Energy Commission, on the occasion of the Founder’s day (October 30, 2001) at BARC]
Every year, we meet on this day to take stock of our achievements and to rededicate ourselves to the ideals and goals set forth for us by our founder Dr. Homi Jehangir Bhabha. This year is particularly important since the IX Five Year Plan is coming to a close in a few months from now and the process of formulation of the X Five Year Plan is now under way. … To facilitate networking of activities of different groups engaged in similar or complementary areas, we have divided our activities into six major programmes with identified key drivers for each one of them. …. In the Department of Atomic Energy (DAE) we have considerable experience in converting our research efforts into successful large scale deployment. We must take these capabilities and their applications to greater heights. We know we can do it. Also we know that the nation expects this from us.
Our commercial nuclear power programme has been doing extremely well. Nuclear Power Corporation, which is responsible for this programme has demonstrated a very high level of excellence in the performance of operating power stations as well as construction projects. The high capacity factors in excess of 80 percent annual average for all plants put together and the power reactor construction programme getting implemented ahead of schedule have given us the confidence to enhance our competitive edge in the electricity market in the country. In addition to the ongoing construction of Tarapur units 3 & 4, each with 540 MWe capacity, we are also beginning construction activities for the 3rd and 4th units at Kaiga (each 220 MWe), the two 1000 MWe VVER units of advanced version at Kudankulam and two more 220 MWe units (unit 5 & 6) at Rawatbhatta. This construction programme when completed would add roughly 4000 megawatts of nuclear power generation capacity in addition to existing capacity of 2720 megawatts. Speedy completion of this construction programme along with sustained excellence in safe and economical nuclear power generation is the most important challenge before us and I am sure, all of us together will work hard to meet this challenge. After all, in the context of our ambition to enhance the share of nuclear power in overall electricity generation capacity in the country this is only a beginning.
While we move on the path of excellence in our operation and construction programme, we should also remember that technology never remains static. It needs continuous upgradation. I am extremely pleased at the programmes that have been taken up by NPCIL for enhancing the rating of 500 MWe units significantly through the use of limited boiling in coolant channels along with the activities to uprate some of the operating units. At one point of time we had planned to set up 10,000 MWe nuclear power capacity by the year 2000. Let us realize this target in the next 10 years and also achieve the objective of realizing 20,000 MWe capacity by the year 2020.
The excellent performance in our power programme was matched by excellent performance in fuel manufacture and heavy water production. Our Heavy Water Plants registered a substantial reduction in energy consumption resulting in reduced production costs while maintaining an excellent safety record; similarly, the Nuclear Fuel Complex exceeded its target production for the third successive year. Programmes are now well underway to demonstrate front-end technologies for our heavy water plants, which would enable them to be delinked from fertilizer plants, which themselves are undergoing a technology change.
At this stage I must reiterate the very high importance that we all attach to health, safety and environment matters. And it should be our endeavor to continuously excel on this front alongside our search for excellence in technology application area. A multi-pronged approach is required to ensure safety. Primary among these is the fostering of a safety culture and development of technologies. Development of world-class plant simulators for improved operator training and the first of its kind that was recently installed at the Kaiga Atomic Power Station is an important step in this context.
Our own research on health effects in natural high radiation background areas as well as the work of other scientific institutions does not show any significant difference between the health of the population living in these areas as compared to those living in normal radiation background areas. The radiation exposure in these natural high background areas is considerably higher than the permissible radiation level for members of public.
The Atomic Energy Regulatory Board (AERB) has reported near total compliance in the year 2000-2001 with its reduced annual permissible limits (30 mSv) on radiation dose to workers in the radiation installations in the country. As part of the policy of assuring a sound environmental management system, power stations at Tarapur, Narora, Kakrapar and Kalpakkam and also the heavy water plant at Manuguru have obtained the ISO 14001 certification. Heavy water board has also developed a technology for reduction of fly ash emission through the stack of coal-fired boilers.
Development of fast breeder reactor technology is of crucial importance in our efforts to exploit full energy potential in our uranium and thorium resources. The indigenously developed uranium plutonium mixed-carbide fuel has shown excellent performance and is nearing three times the original design target. The work on design and development of 500 MWe prototypes fast breeder reactor (PFBR) has reached the stage when we can take up its construction. PFBR would serve as a commercial demonstrator on the basis of which, further construction programme has to follow. The work on fast reactor technology has to be matched with the development of appropriate fuel cycle technologies aimed at minimizing out of pile inventory and realization of short doubling time. From long-term perspective, it is also important that research in actinide partitioning and transmutation is also pursued with a view to gain further advantages in management of nuclear waste.
Consistent with our mission to develop technologies for thorium utilization, the detailed design of Advanced Heavy Water Reactor (AHWR) is nearing completion here at the Bhabha Atomic Research Centre (BARC). A new critical facility is also being set up at BARC for validating the reactor physics aspect of the core design of AHWR. A technology road map on shaping the third stage of our power programme has been formulated and a document on this has been distributed widely. This programme involves a very large number of scientific disciplines and technologies and needs to be pursued as a national programme involving every possible contributor.
Applications of atomic energy in other areas of societal relevance have also received our sustained attention. Radiation processing of agro and other food products would soon become very important in view of the possibility of storage over longer duration without spoilage and better hygienic quality. This technology along with other complimentary technologies can certainly contribute to higher value addition activities and also improved price stability, a factor of considerable importance in strengthening economy in rural India. The high dose spices processing plant of BRIT at Navi Mumbai and a plant nearing completion at Lasalgaon near Nasik for radiation processing of agro products requiring low doses would serve as demonstration facilities of this important technology. We now expect other user institutions and entrepreneurs to take initiative in further deployment of this technology. I am happy to note that the foundation stone of the first private sector commercial plant for radiation processing of food products and sterilization of medical products was laid a few days back. We are in touch with other entrepreneurs and state government institutions to facilitate setting up of more such plants. Centre for Advanced Technology, Indore is working on use of electron beams for food processing.
In the area of nuclear agriculture our research has proved to be beneficial towards enhancing production of important pulses and oilseeds. We have a good network with several agricultural universities. We should now make the benefit of our R & D available to farmers and villagers living in the vicinity of our installations. This would serve the twin objective of demonstration and larger breeder seed production. An institutional mechanism wherein this could be done on the basis of self help with DAE and its scientists playing an interactive and catalytic role needs to be developed.
A long felt need for indigenous formulation of kit for Tc-99m based myocardial perfusion agent has been successfully met by BRIT. The indigenous two component kit for the formulation of Tc-99m methoxy isobutyle isonitrile (MIBI) has been successfully developed and evaluated in multi-centric trials. Availability of this indigenous product marks an important milestone in the field of nuclear medicine procedures for studies in cardiac patients. The first indigenous blood irradiator has been in regular use at the Regional Centre for Radio-pharmaceuticals, KMIO (Kidwai Memorial Institute of Oncology) Campus, Bangalore. Two more such units are about to be installed in Mumbai and Ahmedabad. A programme for development of low cost medical technologies is soon to be launched with full participation of medical specialists, technologists and industry groups.
The Cancer Research Institute of Tata Memorial Centre has been actively involved in basic research and translational research related to cancer. A Western blot kit for the detection of HIV was formulated in the Institute and this is now ready for marketing in India. For the first time in India transgenic mice have been developed and pre-clinical studies for the gene therapy of oral cancer have been completed. Several new areas of research in modern biology, such as brain research, were opened up at TIFR.
The ILU 6 industrial electron accelerator is now in regular operation at Vashi and is available for industry users. The Electron Beam Centre being set up at Kharghar as well as the developments at Centre for Advanced Technology, Indore would support further development and deployment of this important technology for industry use. I’m glad that even in this area facilities are already being set up by the industry. A facility to qualify certain reactor equipment under post loss of coolant accident environment has been set up at Electrical Research and Development Association (ERDL), Vadodra.
In the area of basic research, Indus-1 the first synchrotron radiation source is in regular operation with three of its five beam lines commissioned at CAT, Indore. The work on construction of INDUS-2 is progressing well. Construction of superconducting LINAC booster to enhance the energy of heavy ion beams is in progress at the BARC-TIFR Pelletron Accelerator. The expertise acquired by our scientists in the area of accelerator technology should now enable us to take on, in a step by step manner, more ambitious development of high-power LINAC which has important role in accelerator driven systems, an important energy technology for the future, in addition to its use as basic research tool.
DAE is unique in its technological capabilities both for basic research as well as for application development. We must now synergize our research activities in nuclear sciences and explore possibilities of converting some of the promising developments into front-line technologies. The large number of basic research as well as technology institutions that exist within DAE provide us an unique opportunity for this purpose. Already our linkages with CERN have enabled development and supply of state of art equipment and components.
Nurturing of research and education linkage is another area needing our attention. We have already made a good beginning in parking some of the research infrastructure in academic institutions thereby enabling students to carry out research in areas of interest our programmes. Enhancing the number of students who engage themselves in research activities of interest to us should be an important objective for long-term sustenance of our programme. We are also spreading our induction training programmes to more academic institutions in addition to the new training schools set up at CAT Indore and NFC Hyderabad.
Today is the day for us to introspect and rededicate ourselves for the cause of nation building by implementing applications based on nuclear science and technology in all possible fields. We have to do this by in-house efforts and by involving others from academia and industry. It is only through cooperation of all that we will be able to achieve the vision of our founder.
Dr. Homi Bhabha
Bhabha’s vision on atomic power generation conveyed to Pandit Nehru in a half page summary note on the August 8, 1954 listed 13 items. Each one of these developed into massive programmes covering all aspects of the nuclear fuel cycle. The list included setting up of the Atomic Energy Establishment at Trombay, uranium prospecting and processing, plants to produce heavy water and beryllium, atomic power plants, breeder reactors, a plutonium extraction plant , etc. Among the subsidiary activities he included training and development of manpower, supporting and financing research in the universities (one of his favorite themes) and research institutes and developing and promoting the use of tracers in biology, medicine and industry. This was many years before setting up any nuclear power plant anywhere in the world.
If someone wants to gather information on in any field - be it robotics, high pressure physics, metallurgy or radiobiology, medical physics or biotechnology - there will be at least one specialist available in Trombay. In fact, Dr. Bhabha always asserted that because of paucity of scientifically and technically trained personnel, some of the top people would have to do more than one job at the same time. He ensured that specialists in all disciplines worked together. The greatest strength of any unit of DAE lies in its multi-disciplinary background. It begins in the training school itself. Every one must acquire basic knowledge on all discipline.
The notes from Bhabha to Nehru must be made compulsory reading material for any science administrator. Dr Bhabha was very considerate to the scientists during the construction of various facilities. He argued effectively against outdated government rules and procedures. He provided cars for the scientists on a 24-hour basis; he arranged lunch and dinner for them in the reactor building at Trombay from an appropriate restaurant. Government regulations were against these provisions. Bhabha wrote to Nehru that such rules and regulations are not really suited for executive work, which is to be done at speed and under pressure. Nehru agreed.
January 24, 1966 was one of the saddest days for the Indian scientific community. An Air India plane crashed near Mont Blanc Peak. There were no survivors. Bhabha was in the aircraft. The news shocked us. Next day we worked. All the institutions under DAE were open that day to honor the memory of a great karma yogi. I vividly remember that day. An eerie silence pervaded everywhere. Many wept. The sense of loss among the senior scientists was total.
National Symposium on Thermal Ecology
DAE has initiated a unique coordinated research project at sites where nuclear power plants are located or proposed to be located, to generate a site-specific data on water quality, temperature profile in the vicinity of the coolant discharge point and studying the behavioral patterns of site-specific water borne organisms due to thermal impact.
Organized by the Board of Research in Nuclear Sciences (BRNS) of DAE and Sri Paramakalyani Centre for Environmental Sciences, Manonmaniam Sundaranar University, the objectives of the National Symposium on Thermal Ecology (NSTE) is to bring together scientists in universities, national institutes, power plants and industries engaged on different aspects of temperature tolerance studies of water borne organisms both in the field and laboratory and executives manning various plants and also involved in formulating norms for discharge of effluents into water bodies.
The Symposium to be held during February 1-2, 2002, in Manonmaniam Sundaranar University, Tirunelveli,l focus on the following topics:
- Temperature profile in water bodies and in the vicinity of coolant discharge point, by different techniques.
- Modeling the temperature profile and other characteristics of water bodies.
- Different aspects of temperature tolerance of organisms in the field and laboratory studies.
- Thermal impact on physiology and biochemistry of water borne organisms.
- Influence of thermal discharge on the performance of various process systems
For details, please contact:
Prof. Dr. N. Sukumaran Convener, Technical Committee, NSTE,
Sri Paramakalyani Centre for Environmental Sciences,
Manonmaniam Sundaranar University,
Alwarkurichi-627412, Tamil Nadu, India
5th Meet of the DAE Library & IT Professionals
The 5th Meet of the Library & Info-Technology professionals was held at the Institute of Physics (IOP), Bhubaneshwar, Orissa during July 23-24, 2001. The meeting was inaugurated by Dr. R. K. Choudhury, Director, IOP.
The technical session started with presentation by M/s Elsevier Science on e-journals consortia and about Science Direct (full text scientific database). The Centre for Advanced Technology (CAT) Indore presented the standardized form for DILL (Digital Inter-Library-Loan) which has been made in accordance with the ISO-10161 format. DILL facility will help DAE organization in their knowledge-resource sharing.
There were short presentations by the representatives of various institutes. These presentations focused on the progress made till date at their respective units on resource sharing. These also threw some light on the resources available at various units and the resources that can be shared among the units. Various aspects of the networking and resource sharing which will help to maintain a proper Union Catalogue, were discussed.
The use of ANUNET in the library resource sharing and cataloguing was discussed extensively. The IOP will also host the database for Union Cataloguing. There was also a presentation by M/s World Scientific for online journal
Development & Applications of Electron Accelerators
- H. C. Soni
- Centre for Advanced Technology
Due to remarkable development in accelerator related technologies during past two and half decades, it has become possible to construct a tailor made accelerator most suited for a specific application. This in turn has resulted in tremendous advantage in terms of cost of process or quality of process in comparison to conventional techniques. At present more than 10,000 accelerators are being used all over the world in the areas of healthcare, industry, agriculture & environmental protection.
The accelerators are used in the area of healthcare for treatment of cancer patients, for diagnosis of disease by imaging the organs of human body and for sterilization of medical products and hospital wastes. As per modern cancer treatment procedures 64% patients need treatment by radiation. The rapid development of radiation sterilization over past twenty years has been associated with the widespread use of disposable supplies and sterile dressings. In developed countries 60% of medical supplies are sterilized by radiation processing due to reliability of disinfection and safety for workers and consumers. The products being sterilized are such as hyperdermic syringes, blood transfusion kits, blood oxygenators, haemo-dialysis units, rubber gloves, catheters, dressings and dai-kits.
The technique of electron beam irradiation is used in industry to improve the quality of manufactured goods, to make products of entirely new properties, to reduce the production cost and to reduce pollution due to process. The products range from computer disks, shrink packaging materials, tyres, cables, composites, hot water pipes to cosmetics. More than 1500 electron accelerators are being used in the industry all over the world. In our country TV industry, telecommunication industry , etc. import radiation processed XLPE or XLHDPE quality cables & wires. Indian railways alone import Rs 100 crore worth of such cables per annum.
In agriculture sector the electron accelerators can be used for preservation, hygenisation, quarantine and delaying the ripening of agricultural and food products.
The electron accelerators are being used for cleaning flue gas from thermal power plants before discharging into the atmosphere. The pollution due to sulphur dioxide and oxides of nitrogen is reduced drastically by this technique. It has been implemented in some of the thermal power plants in Japan and Germany. The irradiation facilities for treatment of sewage from cities which can subsequently be used as fertilizer or as an additive to fodders, in operation in several countries.
After considering the vast potential of electron accelerators as mentioned above, DAE had set up an electron accelerator based experimental facility in 1987-88 and took up the development of electron accelerators for these applications in the IX plan. The experimental facility has demonstrated the technical and economical viability of electron beam processing of several products like wires and cables, O-rings, diamonds, , etc. As a result of the work carried out at this experimental facility, NICCO Corporation Ltd. And Radiant Cables are now setting up electron beam processing facilities for cables and wires.
DAE is currently developing following electron accelerators for various applications:
- 500 keV, 10 kW Industrial Electron Accelerator for Radiation Processing of paints and thin products.
- 750 keV, 20 kW Industrial DC Accelerator for Radiation Processing of Wires, O-rings, Pulp sheets , etc.
- 3 MeV & 10 MeV Accelerators for Industrial Products.
- Radiotherapy Machine based on 12 MeV Microtron for Treatment of Cancer Patients.
- 10 MeV, 1 kW Mcirotorn and 10 MeV, 10 kW Linear Electron Accelerator (Linac) for Radiation Processing of Agricultural Products and Sterilization of Medical Products
It is also planned to set up a demonstration facility, by using 10 MeV, 10 kW Linac for Radiation Processing of Agricultural Products, at Indore and Industrial Electron Beam Processing Centre at Navi Mumbai.
The electron beam processing is an emerging technology in India and it is certain that it will play an important role in economic development of the country in near future.
Radio-Techniques in Diagnosis and Treatment of Cancer
- Dr. Ashok Mohan
- Technical Adviser to Director, Tata Memorial Centre
Very soon after the discovery of X-Rays and Radium it was realized that they can have immense medical benefits if used judiciously. During the last 100 years we have witnessed major advances in the technology which has led to the use of radiation for the diagnosis and therapy of cancer.
Digital Radiography/DAS Unit in operation at Tata Memorial Centre, Mumbai
- Conventional Radiology: Conventional radiology forms the backbone of the department of Radiodiagnosis. In addition, specialized contrast procedures such as barium studies, intravenous urography, myelograms and angiograms are performed under fluoroscopic guidance using image intensifier - TV systems to study different organ systems in the human body such as gastro-intestinal, genito-urinary and vascular systems. A specialized orthopant-omography unit is employed to obtain panoramic views (of the upper and lower jaws) for evaluation of disease involving the teeth and jaws.
- Mammography: Mammography is of great value in early diagnosis of breast cancer, even before a lump becomes palpable on clinical examination. Mammography guided sterestactic biopsy is performed to confirm the diagnosis of cancer in doubtful cases. Newer mamography units have digital spot filming and digital sterestatic biopsy facilities for quick and highly accurate biopsy of suspicious lesions.
- Ultrasonography and Colour Doppler: Ultrasonography is a safe and relatively inexpensive imaging modality, which uses high frequency sound waves and is often as the initial screening method to investigate suspected tumours and other disorders in various parts of the body. Ultrasound scanners use a variety of multi-frequency probes to examine the abdomen, pelvis and other organs such as the eye, breast, scrotum and thyroid. Special endocavity probes are available to obtain better visualization of the pelvic organs and prostate gland.
Colour Doppler scanners enable colour flow studies to be added to the ultrasound examinations to evaluate blood flow and velocity and assess tumor vascularity. Narrowing and thrombosis of blood vessels can also be diagnosed with this technique.
Intra-operative sonography is performed during surgery for detailed evaluation of the liver, gall bladder and pancreas, to confirm respectability of tumours in doubtful cases, using a portable ultrasound scanner with specialized high frequency probe.
- Computerized Tomography (CT): CT scanning provides cross-sectional, high resolution images of the entire body, using a narrow beam of X-ray from an X-ray tube which revolves around the body. These images display detailed information regarding the size, extend and nature of tumours and other lesions, lymph node enlargement and metastatic deposits in lungs, liver and other organs. The new spiral CT scanners enable an entire volume or organ of the body to be scanned in one or two breath holds, thus eliminating motion and misregistration artefacts. Tiny modules in the lungs and liver can be detected with greater accuracy. CT scanning provides cross-sectional, high resolution images of the entire body, using a narrow beam of X-ray from an X-ray tube which revolves around the body. These images display detailed information regarding the size, extend and nature of tumours and other lesions, lymph node enlargement and metastatic deposits in lungs, liver and other organs. The new spiral CT scanners enable an entire volume or organ of the body to be scanned in one or two breath holds, thus eliminating motion and misregistration artefacts. Tiny modules in the lungs and liver can be detected with greater accuracy.
- Magnetic Resonance Imaging (MRI): This is a method of imaging which employs a combination of a strong magnetic field and radio frequency waves. MRI is of great value for the brain and spine with excellent differentiation of grey and white matter, normal and abnormal tissues. It has also proved to be of value in the head and neck regions and for evaluation of the musculo-skeletal system and joints. It depicts changes in bone marrow with great clarity. This is a method of imaging which employs a combination of a strong magnetic field and radio frequency waves. MRI is of great value for the brain and spine, with excellent differentiation of grey and white matter, normal and abnormal tissues. It has also proved to be of value in the head and neck regions and for evaluation of the musculo-skeletal system and joints. It depicts changes in bone marrow with great clarity.
There are some techniques which have special advantages.
MR Cholangio-pancreato-graphy is a non-invasive method for depicting the biliary tree, pancreatic duct and gall bladder. It is most helpful in cases of obstructive jaundice. Diffusion imaging is helpful for detecting early brain infarcts. MR Spectroscopy (hydrogen and phosphorus) also measures the levels of certain metabolities in body tissues and organs, which helps in diagnosis of tumours and differentiation from other conditions like infarcts, infective and degenerative lesions.
- Digital Radiography: This is a recent advancement in imaging techniques in which X-ray images are acquired in a digital format. These can be manipulated or magnified to improve contrast and make the lesions look more conspicuous. The improved quality of images can almost eliminate the need for repeat radiographs. Digital-Subtraction-Angiography (DSA) permits accurate visualization of blood vessels after injection of lower dose of contrast medium as compared to conventional angiography.
The use of ionizing radiation play a major role in the cure or palliation of two thirds of all cancer patients. Ionizing radiation destroy the rapidly dividing cancer cells by damaging the DNA. Radiotherapy is of two types:
- Teletherapy: Where the radiation beam is focused on the tumor inside the body from a distance of 80-100 cm. The radiation beam used is either gamma rays produced by a cobalt-60 radioisotope (Telecobalt) or High energy X-rays produced from a linear accelerator. Teletherapy is the most widely used method and is applicable for all tumor types and location.
- Brachytherapy: Where the radioactive source (cesium-137, iridium-192 , etc.) is placed in direct contact with the tumor. As a result of rapid fall-off of the dose around the radioactive source, brachytherapy gives a very high radiation dose to the tumor with minimal dose to the surrounding normal tissues. For protecting the staff and patients, radioactive sources can be after-loaded either manually or by remote after-loading computer controlled systems.
Spiral Computerized Tomograph (CT) Scanner
The Tata Memorial Centre aptly epitomizes the emerging advances from kilovoltage era of the Fifties to the megavoltage cobalt era of Sixties and Seventies, sophisticated era of linear accelerators, computerized treatment planning and simulation of the Eighties and optimized and conformational radiotherapy of the Nineties. The sophisticated technical advances such as Stereotactic Radiosurgery (SRS), Stereotactic Radiotherapy (SRT) and Intensity Modulated Radiotherapy (IMRT) with total computer-networking are the latest additions for delivering state-of-the-art patient care. The success of radiation therapy depends on precision and accuracy of planning and delivery of treatment. These modem radiotherapy techniques allow very precise and focused irradiation of the tumor while protecting the surrounding normal organs. The knowledge of radiation dose distribution is of prime importance in the treatment planning in radiation therapy. The Treatment Planning Systems cater to the above needs, displaying the radiation dose distribution in three dimensions and with desirable orientation.
Modern radiotherapy using appropriate technologies has proved an invaluable tool for relieving the suffering due to cancer and also curing this disease when detected at an early stage. The focus now is to refine the techniques so as to reduce the side effects of the treatment and further escalate the radiation dose with the hope of increasing the cure rates.
Development of Lasers for Industrial and Medical Applications
- A. K. Nath and D. D. Bhawalkar
- Centre for Advanced Technology
Lasers, because of the unprecedented precision and power of their beam are finding widespread applications in all aspects of human endeavor-industry, medicine, research and even entertainment. The Centre for Advanced Technology (CAT) at Indore in Madhya Pradesh where research and development of various kinds of lasers, accelerators and their applications are being done, has developed several lasers for industrial and medical applications. These include high power continuous wave (CW) carbon dioxide (CO2) lasers with power up to 10kW, high repetition rate pulsed TEA CO2 laser of 500W average power, Nd:YAG laser, 10-40W copper vapor lasers, Excimer laser and nitrogen laser.
3.5 kW Industrial Carbon dioxide Laser and (right) High Repetition Rate TEA Carbon-dioxide Laser developed at CAT
CO2 laser is one of the most remarkable laser systems because of its high efficiency, high power capability and operation versatility. It lases in the mid-infrared region (wavelength in 9-11 micron) and can be operated at high power levels in both CW and pulsed modes. Diffusion cooled 100W single beam and 500W multi-beam CW CO2 lasers have been developed and many such units have been given to different institutes and industries for various material processing applications. High power transverse gas flow CW CO2 lasers up to 10kW have been also developed. These have been coupled with CNC workstation and are being regularly used for cutting of metal and non-metal sheets, welding, surface modifications through transformation hardening, surface alloying and cladding. Laser welding of end plug PFBR (prototype fast breeder reactor) fuel tubes (D9-steel with SS316L), surface cladding of turbine blades made of Ni- super alloy with stallite 694, surface hardening of various kinds of steels, surface alloying of different types of substrate materials with a variety of alloying materials were successfully done with these lasers. Recently, laser scabbling and drilling of concrete was done, which can have potential application in decontamination and decommissioning of nuclear facilities.
Nd:YAG Lasers operating at 1.06 micron in infrared have been also developed up to laser power of 250W for industrial applications. One of the advantages of Nd:YAG laser over CO2 laser is that Nd:YAG laser beam can be transmitted through low-loss optical fiber whereas such fiber is not available for transmitting CO2 laser beam. A Nd:YAG based fully computer controlled laser welding system for the welding of the heart pacemaker was developed which is being used by a private company for last many years. Several other systems such as laser marker, micro-drilling system and diamond cutting system incorporating Nd:YAG lasers have also been developed. Recently, an optical fiber coupled Nd:YAG laser system has been developed for remote cutting & welding of nuclear components in radioactive environment. The average power of the laser is 250W and the beam can be transmitted through 0.6mm diameter and 50-100 m long optical fibre with about 1-2% power loss.
Copper Vapor Laser (CVL) operating at green and yellow wavelengths, provide very large average powers and are widely used for pumping dye lasers. CVLs giving 40-watt average power have been developed here. Nearly diffraction limited output beam have been obtained using novel resonator configurations. Such lasers can be used for cutting and microdrilling in reflecting materials such as copper.
The centre has developed several other laser-based systems for industrial and medical applications. For example, using N2 lasers developed at CAT, laser fluorescence spectrometer to detect trace amounts of uranium has been developed. This can trace uranium in aqueous solutions, including naturally occurring waters up to 0.2ppb level. Several units of DAE are regularly using these units supplied by CAT for the detection of uranium.
Similarly, a surgical laser system based on 50W CW CO2 laser and integrated with a seven-joint articulated arm has been developed. Several such units have been given to different hospitals in India for their use and evaluation.
A high repetition rate (100Hz) N2 laser with an average power of 2.5mW and a fibre optic delivery system, has also been developed for the treatment of pulmonary tuberculosis and non-healing wounds, ulcers and burns
More recently, a laser induced fluorescence spectroscopy based technique employing N2 laser has been developed for early stage detection of cancer of different parts/organs of the body such as oral cancer, breast cancer and uterine cancer. In vitro studies have shown very encouraging results and now in vivo studies on the diagnosis of oral/cervical cancer have been initiated.
Development of several other laser systems such as excimer lasers, iodine laser, diode laser pumped solid state lasers and laser-based instruments for industrial and medical applications is also in progress.
High Resolution Transmission Electron Microscope Facility at the Institute of Physics
- P. V. Satyam, Arun K. Dash, S. Mahapatra and B. Satpati
- Institute of Physics, Bhubaneswar
A 200 keV (JEOL 2010) High Resolution Transmission Electron Microscope (HRTEM) with point-to-point resolution of 0.19 nanometer, has been installed at the Institute of Physics, Bhubaneswar. This facility will be used to study morphological and crystallographic information in various materials down to atomic scales.
The system has a magnification of 1.5M (million) and is equipped with a TV camera system which further magnifies the image by a factor of 20. The camera system makes use of the image formed on a yttrium-aluminum-garnet (YAG) screen which is fibre optically coupled to an image intensifier connected to a high resolution TV tube. The output of this system is grabbed with a frame grabber. This way the images or diffraction patterns are directly acquired in a personal computer. The option of taking pictures with photographic films is also available.
Fig.1: Transmission Electron Microscope (TEM) machine along with the GATAN accessories
|Resolution||0.19 nm (point to point), 0.14 nm (lattice resolution)|
|Magnification||x 50 to 1.5 M|
|Gatan Camera||x 20|
|Camera Length||8 to 200 cm|
|Condenser Lens||4-stage system; five apertures (19, 20, 50,70 and 120m m) 5° deflection (maximum).|
|Object Lens||URP-22; four apertures|
|Image forming Lens||OM lens, 1st, 2nd, 3rd Intermediate Lenses, Projector Lens; four aperture|
|Specimen Stage||Side-Entry; Single tilt and double tilt stages; Tilt angle: 20|
|Films||65 mm x 90 mm (standard size)|
|Gatan Camera||622 SC fibre optic TV system, Video Image Processor and TV Monitor|
|Vacuum System||Rotary pump, Oil diffusion pump and Sputter ion pump (SIP),|
|Working Vacuum||10-5 Pa|
The TEM consists of three major components: the illumination system, the object lens/stage and the imaging system.
The illumination system comprises the electron gun and condenser lenses. Its role is to take the electrons from the source and direct them at the specimen. One can choose to have a parallel beam for imaging and diffraction or a convergent beam for micro-diffraction. There are three condenser lens coils, one condenser mini-lens and deflector coils for the gun and condenser lenses.
Fig.3: Cross-Sectional TEM of Gold Silicide
The sample (side-entry, single tilt and double tilt stages) which is very thin (electron transparent) goes in between the pole pieces of the object lens. The pole piece (object lens) in the TEM machine provides ultra high resolution. In this section, the interaction between electron beam and specimen takes place and the bright-field, dark-field images and diffraction patterns are created.
The quality of the image formed by the object lens controls the resolution of the image.
The imaging system uses intermediate lens, projector lens, shift, deflector and astigmator coils to align and magnify the image or the diffraction pattern produced by the object lens and to focus these on the viewing screen.
To test the high resolution of TEM machine, imaging is done on a test sample i.e., gold nano crystals grown on amorphous carbon. High resolution picture taken at a machine magnification of 1.0 M (million) and with additional magnification of factor of 20 from the Gatan camera is shown in Fig.2.
Nano and Micro Structures
Au/Si: Gold silicides have been formed by appropriate surface treatment of single crystal silicon which follow a shape transition in their growth. The gold silicide island growth varies from 1-100 microns. Cross-sectional TEM measurements show that these islands are single crystalline.
Using TEM, IOP could determine that gold cross-sectional TEM of gold silicide silicide is single crystalline in nature.
Work on nano materials fabricated by chemical methods such as electro-deposition has been carried out. Structural investigations of surface/interface modification due to energetic ion bean irradiation, thin films and micro structures formed with ion microbeam are planned for the near future.
The HRTEM machine is being used for the study of morphological and structural changes and can be applied in many inter-disciplinary areas such as biology, materials science, quantum devices and soft condensed matter physics et.
Fig.4: Diffraction Pattern from Silicon
Fig.5: Diffraction pattern from silicon and silicide. There are extra spots compared to Fig.4. These extra spots arise from gold silicide
Automatic Dependent Surveillance System Developed by ECIL for Civil Aviation
ECIL has been a pioneer in developing products and systems for the strategic sector. The Automatic Dependent Surveillance System (ADS) developed by the company for civil aviation, has been installed and commissioned at Chennai and Kolkota recently. ECIL has received orders for modernizing four more international airports on the same lines.
Air Traffic Management and Control is a complex process involving monitoring the flight profiles, crisscrossing traffic, flight separation and conflict resolution from departure-to-arrival of aircraft. Added to this is the critical requirement of safety, security and efficient operations and capability to handle increased traffic. As safety and efficiency play a very important role, manual systems, due to their limitations have paved the way for automation of air traffic control.
To overcome the drawbacks and to meet the demands of the future, the international Civil Aviation Organization (lCAO), had proposed the use of satellite technology for communication, navigation and surveillance (CNS) for total Air Traffic Management (ATM). The surveillance radars being used by the civil aviation, cover only the land areas and over the oceanic region, which most international flights use, no surveillance facility is available. Taking into account the requirements of ICAO and the surveillance over the oceanic region, ECIL undertook the development of ADS and a prototype was installed at Chennai for evaluation by the Airport Authority of India (AAl) much ahead of other countries. A number of additional user related features and air traffic management and modernization facilities were incorporated and ECIL delivered the production systems to Chennai and Kolkata.
The main application of ADS is to provide surveillance and monitoring of aircraft over the oceanic region, compliment the radar surveillance over the land areas, process flight plan and flight data and provide conflict probe and resolution, provide total air traffic situation display, controller-pilot data link communications and interface to aeronautical fixed telecommunication network and airfield terminal information system. The hardware consists of two servers in ‘fail safe’ configuration for each of main processing and communication front-end and other accessories and communication elements.
The ADS system, as developed and supplied by ECIL, state-of-the-art equipment which meets international specifications.
WNA Chief’s Visit
Mr. John B. Ritch, Director General of the World Nuclear Association(WNA) visited India along with his colleague Mr. Rosen Morris mainly to participate in the 12th Annual Conference of the Indian Nuclear Society at Indore, Madhya Pradesh, held during 9-12 October, 2001. The purpose of his visit also included broadening India’s membership participation in the WNA.
On his visit to Mumbai, Mr. Ritch delivered a lecture at Trombay. An industrial meet was arranged at DAE where chief executives of several leading companies and other senior officials had participated. Mr. Ritch was impressed by the progress which India has made in the field of nuclear science and technology. "Indian scientists, in developing peaceful nuclear technology, attained a remarkable record of independent achievement."
According to him, the main objective of the Association was to provide reliable information on nuclear energy and to speak proactively on behalf of nuclear industry amongst policy makers opinion leaders and in UN bodies focused on climate change and sustainable development. He recommended steps that could be taken to remove the barriers that now separate India from the global nuclear community.