Centre for Advanced Technology
INDUS-1, the first Synchrotron Radiation Source (SRS) of India is under regular operation now. A maximum stored current of 175 mA which is 75% more than the design value, has been already achieved. However, for routine operation a stored beam current of 100 mA is used. At this current the life time of the beam is nearly one hour. This lifetime is limited by the pressure in the vacuum chamber which is in the order of 10-8 torr. With operation of INDUS-1, it is expected that the vacuum will improve and a pressure 10-9 torr will be reached. At this pressure, the lifetime is expected to be a few hours.
The INDUS-1 consists of an injector system – a 20 MeV microtron and 700 MeV booster synchrotron and 450 MeV storage ring. All the three accelerators and their sub-systems have been indigenously designed and developed.
The synchrotron radiation emitted by the electrons circulating in the storage ring is in the form of intense narrow fan-shaped beam. The radiation covers a wide spectral range extending from far infrared to vacuum ultraviolet – down to 20 A. Further, the synchrotron radiation seen from a fixed point is in pulses of 1-2 nanosecond duration. These properties make synchrotron radiation a powerful tool of research in a wide-ranging areas of science and technology.
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In order to utilize the radiation from INDUS-1, five beamlines have been planned. Of these, two are already installed and commissioned – one designed, developed and constructed at CAT and the other one designed, developed and constructed at Interuniversity Consortium for DAE Facilities, Indore. The beamline developed by CAT is based on torroidal grating monochromator with a wavelength range of 40-100 A with a resolution of between 500 and 800. The entire beamline is in UHV. The beamline was commissioned on 27th November 2000 and the first reflectivity spectrum of Platinum Carbon Multilayer was recorded on 4th December 2000. The beamline is now routinely used for measurement of reflectivity of various thin films and multilayers.
INDUS – 2
INDUS - 2 is the second electron storages ring under construction at CAT. It will have nominal operating electron energy of 2.5 GeV. Injector system, presently working for INDUS –1 will also provide accelerated electron beam of 700 MeV to INDUS –2. This 700 MeV beam will be further accelerated after injection into Indus –2 up to 2.5 GeV and stored there. Fabrication of dipole magnet core and magnet cores for quadrupole and sextupole magnets are under fabrication at different industries. All the magnet coils are under fabrication in-house. UHV pumps like sputter ion pimps and titanium sublimation pumps are under production in-house. Indigenous development of UHV measuring instruments has been completed and batch production completed with assistance of ECIL, Hyderabad. Construction of the shielded ring that will house INDUS – 2 has been completed including electrical and A/C works. Experimental hall and users laboratories are under construction.
Laser Programme
A high power transverse flow CW CO2 laser delivering 7.5 kW laser power has been developed for various material processing applications suchas deep penetration welding, cutting of thick sheets, laser cladding and rapid prototyping.
Several novel electrical circuit schemes, such as ballast free spark pre-ionization using mutually coupled inductors for the high repetition rate TEA CO2 laser and Series IGBT based high voltage chopper for laser power modulation of the 3.5 kW CW CO2 laser were developed. These have improved the performance of lasers considerably.
Studies towards gram-level separation of C-13 isotope by selective photo dissociation of Freon 22 with high repetition rate TEA CO2 laser were carried out. Selection of optimum experimentation parameters e.g. laser rotational lines, laser fluence, Freon gas pressure and buffer gas pressure for maximum yields and selectivity were made. Experimental set up for gas irradiation with laser pulses at high repetition rates is being made.
A three axis computer controlled workstation which can provide very accurate and fast control with linear, circular and helical interpolation and can give trapezoidal and S-curve acceleration and declaration has been developed. A capacitor sensor for on-line control of gap has been integrated with Z-axis for laser contour cutting of metal sheets.
High current short pulse duration capillary discharge could be a potential source of soft x-rays. An electrical circuit for generating ~40kA 50ns current pulse for capillary discharge has been developed.