A working group of the cyclotron centre started its journey at about two decades ago for the development of the first indigenous Electron Cyclotron Resonance Ion Source in our country. After design, development and testing, the source had been engaged for successful injection of the multiply charged ions into the Room Temperature Cyclotron for prolong period, along with its constant improvement in performance through several research and development activities. In recent past, with the changing requirements, the activity was directed towards the material science and atomic physics research. This 6.4 GHz ECR source has been utilized to develop aunique fully indigenous low energy heavy ion implantation facility. The material scientists from several reputed institutes and universities of our country are utilizing this facility to carry out successful experimental research at our centre.

ECR ion source based low energy ion beam facility at VECC

Low energy ion beams provide a controlled means for modifying material surfaces for the achievement of desired properties. Such ion beams have ranges of few tens of nanometers in most of the materials and hence are suitable for surface modification studies. A unique, low energy heavy ion irradiation/implantation facility has been developed at VECC for materials science and atomic physics research. The facility utilizes the indigenously developed 6.4 GHz ECR ion source, which was earlier being used to inject heavy ions into the room temperature cyclotron at VECC. Fundamental and technologically important problems of materials science and atomic physics can be studied with the positive ion beams available from this facility over a broad range of high charge state species like N, O, Ne, Ar, Kr, Xe, Fe, Ti etc. It can deliver ion beams up to a few micro amperes at an energy of 10 keV per charge state, enabling to generate high defect densities i.e. high value of displacement-per-atom (dpa).

The ion beam is focused to a spot of about 2 mm diameter on the target using a set of glaser lenses. AX-Y scanner is used to scan the beam over a target area of 10mm x 10mm for uniform implantation. The sample chamber has provision for mounting multiple samples on indigenously developed disposable type beam viewer for in-situ beam viewing during implantation.

Implantation chamber with sample manipulator Beam spot on viewer Target Ladder Assembly

To meet the requirements of the material scienists, ion beams of S, Fe, Ti and Hf have also been developed using the MIVOC technique. In this method, the ion source feedmaterial usually is a high vapour pressure compound containing desired element. It has been observed that to obtain good yield the vapour pressure of the compound should lie between 10 to 0.1 Torr at room temperature. A dedicated set up has been developed for this purpose which has the pumping and vacuum measuring facility of its own. The MIVOC setup is electrically isolated from the ion source enabling its operation at ground potential. The vapour of the MIVOC compound is injected into the ion source using an electro-mechanically operated sapphire seal valve. With this arrangement it is possible to optimize the ECR parameters for the desired ion species. It has been observed that for certain ion species a suitable mixing gas is essential for improving the required beam yield.

Facilities Available:

  • Ion beams of gaseous elements, metallic and non-metallic elements byMIVOC method
  • Provision for varying charge state and energy (up to 10keV/charge state) of different ion species
  • Target ladder assembly to accommodate multiple targets
  • Indigenously developed online beam viewer
  • Raster scanner for uniform implantation


Journal Publications:

[1] G. S Taki, P. R Sarma, D. K. Chakraborty, R. K. Bhandari, P. K. Ray and A. G. Drentje, "Abrupt variation in ion current with biased disc voltage in the electron cyclotron resonance ion source" Rev. Sci. Instr. 77, 03A310(2006)
[2]G. S. Taki, P. R. Sarma, A. G. Drentje, T, Nakagawa, P, K. Ray and R. K. Bhandari, "Observation of Burst Frequency in Extracted ECR Ion Current", Chinese Journal of High Energy Physics and Nuclear Physics, 31,170 (2007)
[3] G.S.Taki, P.R. Sarma, D.K.Chakraborty, R. K. Bhandari and P.K.Roy,"Experimental study of the dependence of beam current on injection magnetic field in 6.4 GHz ECR ion source", PRAMANA¬¬- J. Phys. 67, 477 (2006)
[4] P. R. Sarma, G.S. Taki and R.K. Bhandari, "Enhancement of electron heating in an ECR trap having a mixed multipole field – a Monte Carlo study", Nucl. Instrum.and Methods in Phys. Res. B264, 140 (2007).
[5] Subhashghosh, G S Taki, C Mallick and R K Bhandari, "A study on vacuum aspects of Electron Cyclotron Resonance Ion Source Plasma", Journal of Physics: Conference Series 114 012066 (2008)
[6] G.S.Taki, D.K Bose, P.Y. Nabhiraj and R. K. Bhandari, "Operational Experience with VEC-ECR Ion Source" Indian J. Pure Appl. Phys, 39, 41(2001)
[7] G.S.Taki, D. K. Chakraborty and R. K. Bhandari, "6.4 GHz ECR Ion Source at VECC", PRAMANA- J. Phys, 59, 775 (2002)
[8] D.K. Bose, G.S.Taki, P.Y. Nabhiraj, Gautam Pal, C. Mallik and R. K. Bhandari,"ECR ion source for accelerating heavy ions with VEC", Indian J. Phys. 73S(2), 35 (1999).
[9] D. K. Bose, G. S. Taki and R. K. Bhandari, "Status of VEC ECR Heavy Ion Source" Indian J. Physics,66B, 629 (1992).
[10] Ashutosh Kumar, J. B. M. Krishna, Dipankar Das, SunitaKeshri, "Conductivity modification of znO film by low energy Fe10+ ion implantation" Applied Surface Science 258, 2237 (2012).
[11]A. K. Himanshu, S.K.Bandyopadhayay, P.Sen,N. N. Mondal, A. Talpatra, G.S.Taki. T.P.Sinha,Electrical properties of low energy Ar9+ irradiated conducting polymer PANI-PVA,Radiation Physics and Chemistry 80, 414(2011).

Symposium publications:

[1] G.S.Taki, D K Chakraborty, Subhash Ghosh, S. Majhi, Gautam Pal, C. Mallik, R. K. Bhandari, J. B. M Krishna, K Dey, A K Sinha, ECR Based Low Energy Ion Beam Facility at VECC, Proc. International Symposium on Vacuum Science and Technology and its Application for Accelerators (IVS-2012)VECC, Kolkata [Invited Talk]
[2] G.S.Taki, D.K.Chakraborty, S.K.Bandhopadhyay, S.Majhi, C.Mallik, R.K.Bhandari, J.B.M.Krishna, K.Dey, A.K.Sinha, ECR Ion Source Based Low Energy Ion Beam Facility at VECC, Proc. Indian Particle Accelerator Conference (INPAC) 2011, New Delhi [Invited Talk]
[3] G.S.Taki, P.R.Sarma, J.B.M.Krishna, D.K.Chakraborty, S.R.Das, K.Remashan, T.Mallik, A Novel Powerful Beam Steerer cum Scanner for ECR Ion Beam at VECC, Proc. of DAE Nuclear Physics Symposium, 2009
[4] P.R.Sarma, G.S.Taki, D.K.Chakraborty, J.B.M.Krishna, Measurement of the Emittance of an ECR Ion Source using a Glaser Magnet, Proc. of DAE Nuclear Physics Symposium, 2009
[5] G. S Taki, P. R Sarma, D. K. Chakraborty, R. K. Bhandari, P. K. Ray and A. G. Drentje, Study of the Dependence of ECR Ion Current on Periodic Plasma Disturbance, Proc. International workshop on ECR Ion Source-2008, Chicago, IL USA, 169 (2008) [6] G.Bakiaraj, J.B.M.Krishna, G.S.Taki R.Dhanasekaran, Effect of Nitrogen Ion Implantation on the CdS Nanostructured thin Films Prepared by Chemical Bath Deposition, ICMAT11-A-2438 SUNTEC, Singapore, 2011
[7]P.Kannapan, J.B.M.Krishna, G.S.Taki, R.Dhanasekaran, Effect of N Ion Implantation in Cvt Grown Znse Single Crystals, Symposium EE: CGCT-5-Fuctional Materials Crystallization, Characterization and Devices ICMAT11-A-2182, SUNTEC, Singapore, 2011
[8] S.K.Bandhyopadhyay, A.K.Himanshu, G.S.Taki, J.B.M.Krishna Magnetism in Fe implanted Ho , Proceedings in Symposium on Current Trends in Condensed Matter Physics, NISER, Dec., 2010.
[9] S.K.Bahdhyopadhyay, A.K.Himanshu, G.S.Taki, Irrradiation on ZnO Film Proceedings in Symposium on Current Trends in Condensed Matter Physics, NISER, Dec. 15-19, 2010.
[10] U. C. Bind, J.B.M. Krishna, Kamal Dey, G.S. Taki, K.L. Yadav, R.K. Dutta, Preliminary results on the effects of 63 keV high charge state oxygen ion beam implantation on PMMA, Nuclear and Radiochemistry Symposium (NUCAR- 2011), GITAM University, Vishakapatnam.
[11] G. S. Taki, P. R. Sarma, A. G. Drentje, T, Nakagawa, P, K. Ray and R. K. Bhandari, "Periodic Ion Current Burst in 6.4 GHz ECR Source", Proc. Asian Particle Accelerator Conference, APAC07. [12] G. S. Taki and R. K. Bhandari, "Progress in ECR Ion Source technology", Proc. DAE-BRNS-PSI Symp. on Ion Beam Technology and Applications SIBTA-2007, p.194 (2007) [Invited talk]
[13] G.S.Taki, R. K. Bhandari, D.K.Chakraborty, P. R. sarma, P. K Roy," Field Scaling Law for Ion Current in ECR Source" - The Third Asian Particle Accelerator Conference, Gyeongju, Korea, (2004)
[14] G. S.Taki, D.K.Chakraborty, P.S.Chakraborty, S.Ghosh, V.Singh, C.Mallik and R. K. Bhandari, "Performance of a 6.4 GHz ECR Ion Source at VECC", Proc. Second Asian Particle Accelerator Conference, Beijing, China, (2001), p. 78
[15] D. K. Bose, G. S. Taki, et. al. "ECR Ion Source for Variable Energy Cyclotron", Proc. 12th th Internation Workshop on ECR Ion Source, RIKEN, Japan (1995), p.237.
[16] Bikash Sinha, D. K. Bose, G. S. Taki, et. al. "The Electron Cyclotron Resonance Ion Source at Variable Energy Cyclotron Centre, Calcutta", Proc. International Conf. on Cyclotrons and their Applications, Capetown, South Africa (1995), p. 408
[17] D. K.Bose, G. S. Taki, et. al. "ECR Heavy Ion Source and External Injection System for Calcutta Variable Energy Cyclotron", Proc.12th International Conference on Cyclotron and their Applications. Berlin,(1989), p.190.

P. Y. (HEAD)