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Mandal, A.

Paper Title Page
WEPMA110 Development of 100 kW RF Amplifier for Superconducting Cyclotron at VECC 476
 
  • S. S. Som, M. B. Banerjee, D. S.B. Bhattacharyay, S. B. Biswas, P. G. Gangopadhyay, A. Mandal, S. K. Manna, A. K. Mukherjee, S. P. Pal, J. S.P. Prasad, P. R. Raj, M. S. Saha, S. Saha, S. Seth, K. V. krishnaiah
    DAE/VECC, Calcutta
 
  High power rf amplifiers (3 nos.) have been developed at our centre for feeding power to three nos. of coaxial rf cavities of the k500 Superconducting Cyclotron. Each of this amplifier can supply output power of 100 kW (max.) at 50 Ω impedance within the frequency range of 9 MHz to 27 MHz. The amplifier, based on Eimac 4CW 150,000E water-cooled tetrode, is tuned by moving the sliding short of the coaxial cavity within the said frequency range. An inductive coupling loop is inserted along one side of the coaxial cavity through the sliding short and is matching the output impedance of 50 ohm. The four identical Bridge-T network in the grid of the final amplifier are driven with equal power levels of up to 150 watts. The amplifier is operated in Class-AB mode with power gain of 22 dB. A PC-based stepper motor controlled sliding short movement system have been done. The frequency response of the input circuit of the amplifier has been measured using Vector Network Analyzer and the result is very satisfactory.  
WEPMA002 A Large Area Scanning Magnet For Homogeneous Irradiation of Targets 339
 
  • A. Mandal, R. Kumar, G. Rodrigues, S. K. Suman
    IUAC, New Delhi
 
  The scanner is an important tool for accelerator based material science research. For high energy (~100 MeV) ion beam scanner has to be magnetic one. Major problem faced with magnetic scanner is its high inductance which causes large impedance to the a.c. power supply used to energise the magnet. We have designed a magnetic scanner keeping attention to minimise its inductance. The scanner is composed of two independent H-type dipole magnets which are fed by saw tooth pulses. It can scan over an area of 25 mm x 25mm at a distance of 1 metre. The power supplies for this scanner have also been designed. These are bipolar, wideband, high speed amplifirs that can reproduce complex waveform without any distotion. The ratings are 60V, 50A operating at 50Hz for x-scanner and 5V,70A at 0.2Hz for y-scanner. Design and performance of the scanner magnet and power supplies will be presented.  
WEPMA078 HTS-ECRIS and Low Energy Beam Transport System of the High Current Injector 434
 
  • G. Rodrigues, R. Ahuja, D. Kanjilal, P. Kumar, P. S. Lakshmy, A. Mandal, Y. Mathur, D. Naik, A. Roy, U. Unnam
    IUAC, New Delhi
 
  A high performance electron cyclotron resonance ion source (ECRIS) called PKDELIS capable of operation at 14.5 and 18 GHz and which uses High Temperature Superconducting (HTS) coils designed jointly by IUAC, Delhi (earlier called NSC), Pantechnik, Caen and ISN, Grenoble is presently in operation. The source is very suitable for operation on a 400 kV high voltage platform for injecting beams from the High Current Injector (HCI) into the Superconducting Linear Accelerator Booster. In the low energy beam transport (LEBT) system of the HCI, the beam extraction and transport becomes more and more challenging. In order to avoid the losses of the beam, the complete transport system is being made as short as possible. In addition, due to the high currents (~10 mA) extracted, the extraction system needs proper cooling requirements and possibility of movement of the electrodes for tuning various A/q beams. Typical axial and radial bremstraahlung spectra have been measured from the ECR plasma. Details will be discussed and further measurements are being explored to obtain a better understanding.