ECR Ion Source

Design Details

The Electron Cyclotron Resonance ion source (supernanogan, designed & manufactured by Ms Pantechnik, France) at TIFR consists of a copper plasma chamber. firefox-gray It is a permanent magnet (SmCo) ECR ion source with dipolar axial and closed structure hexapolar radial magnetic fields. Field maxima at the ends are 0.8 and 1.1 tesla. The micro-wave frequency is 14.5 GHz with 500W maximum output. At this frequency, the resonance magnetic field turns out to be 0.51 tesla. A plasma chamber contains an insulated metal rod (called the bias rod). The maximum extraction voltage is 30 kV. Gases are introduced in the plasma chamber by two electrically controlled gas inlet valves. Extracted ions are focused by an electrostatic Einzel lens. A 900 bending dipole magnet (0.3 tesla) analyzes the charge state of ions. firefox-gray The voltage of the deck can be raised up to 400 kV to accelerate the ions further. The analyzing magnet is joined to the rest of the beam line (on ground) by an accelerating column made of ceramic insulators. Accelerated ions are focused by a set of electrostatic quadruplole lens triplets. A set of X-Y deflectors, two pneumatically controlled Faraday cups and one beam-profile monitor are also mounted. The position and dimensions of different beamline elements were frozen after performing intensive beam transport simulations. GWBASIC code was used to simulate the beamline trajectory with all active elements. ECR ion sources produce high dosage of firefox-gray X-ray radiation and hence, to avoid radiation exposure, the high-voltage deck has been covered with aluminum-covered lead shields Residual radiation outside the shielding was measured near the ECRIS and was found to be well within the safe limit. Vacuum in the plasma chamber is about 8x10-8 mbar or better and that in the beamline is about 8x10-9 mbar. A new motor alternator-generator assembly provides the required power to the electronic modules and power supplies for the micro-wave system, dipole magnet, ion source, etc, on the isolated deck.

Command and Control Unit

A LabVIEW-based command and control system has been developed. Field-point modules along with the controller are mounted on the high voltage deck. The dipole magnet, extraction voltage, Einzel lens, bias rod and gas flow controller channels were controlled through the NI FP AO-200 analogue output module channels. firefox-gray The magnet current, extraction and Einzel lens voltages, Faraday cup current, ECR body temperature and micro-wave tuner position were monitored with the FP AI-110 analogue input module channels. All the field-point modules are cascaded to the FP-2000 real-time controller and connected to the wireless access point kept on the high voltage deck. The PC is also connected through the wireless router. All the control and monitoring parameters of the source are transmitted and received through this wireless mode. There are two separate wireless serial communication channels to control and monitor the micro-wave amplifier.

Switching Magnet

To expand the facility, a switching magnet with five ports has been procured, tested and mounted in the beam line. A new quadrupole system with more efficient design along with the deflectors was inserted in to the beam line to have better optimization capability. firefox-gray Redesigned Einzel lens system has been incorporated in the ECR system for better performance. In the present configuration two more beam lines were under integration process apart from the main zero line for the irradiation and bent crystal spectrometer setup. The whole beam line was aligned with laser beam to have efficient beam optics. Various high voltage power supplies were configured to connect to various ports of the quadrupole and deflector systems. Beam optimization is on at the main port with much better beam current.

Security Measures

To avoid the unauthorized entry in high voltage region, aluminum grill fencing was installed. Stabilization issue with the motor alternator was sorted out with better coupling between the alternator and 3-Phase motor through a insulating shaft and better shock absorbers.

Usage of ECRIS

Our Group

  • Ionization and fragmentation of bio-molecules...
  • High resolution x-ray studies from HCIs using bent crystal spectrometer...
  • Ionization and fragmentation of PAH's including coronene...
  • Sinle and multiple capture for He++ in collisions¬†with Ne...

External Users

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  1. Plasma diagosis of ECR plasma and temperature determinatiuon by looking into high energy X-ray spectrum, Siddharth Kasthurirangan, Institute of Chemical Technology, Mumbai.
  2. Titanium oxide nanostructures formed by oxygen ion implantation in titanium films, Prof Varsha Bhattacharyya and Deepti. A. Rukade, Department of Physics,University of Mumbai.
  3. Ion beam induced crystallization of amorphous aluminum oxide films, Prof Atul Khanna and Priyanka Nayar, Department of Physics, Guru Nanak Dev University, Amritsar.
  4. Low energy ion collisions with some of the PAH molecules and ToF study, Dr. Umesh R. Kadhane and Preeti Manjari Mishra, IIST, Thiruvananthapuram.
  5. Production and characterisation of 14N implanted target, Prof. M. Saha Sarkar and Abhijit Bisoi, SINP, Kolkata.
  6. Argon ion bombardment on ZnO nanorods: Study of structural and optical properties, Dr. Shyamal Chatterjee, IIT, Bhubaneswar.
  7. Calibration of Thomson parabola set-up, Prof. M. Krishnamuthy, DNAP, TIFR.

If you want to know more about the ECR ion source, click here for our recent publication regarding ECRIS.