Accelerator Activity
Power Supplies Division - Ongoing Activities

• Transmission line type extraction kicker for booster synchrotron

The existing pulser for booster extraction kicker can deliver a maximum peak current of 800A. The rise time of this pulse is in excess of 55 nsec. This prevents extraction of the three electron bunches from the booster, and one bunch is lost as a result. Upgraded pulser has been designed with maximum peak current of 1200A and a much smaller rise time of 25-30 nsec, and tested the prototype version at low charging voltages upto 10 kV with load shorted. This upgraded power supply uses six RG217 cables (12 meters) as PFL. The latter will be charged up to 30kV and discharged into series connection of HV resistor and the load magnet to produce trapezoidal current pulse. New thyratron and cable termination assembly has been designed to achieve faster rise of the current pulse. The testing was done with lumped magnet as well.

 

Specifications

Peak Current

1200 A

Peak Voltage

28kV

Pulse shape

Trapezoidal

Rise Time

<33nS

Flat top

70ns

Fall time

Not important

Jitter

± 3 nsec

Magnet

Transmission line type

PFN Impedance

50/6 Ω

PRR

1 Hz

• Line Side Active Filter:

A line side active filter for reduction of line current harmonics is under development in lab. Three line currents have been sensed with the help of isolation amplifiers. Accurate sensing of these currents is of prime importance for calculation of line current harmonics using DSP. Real time calculation of line current harmonics is done using DSP. Sensed three phase voltages and three line currents are the inputs to DSP for online calculation of current harmonics. All the required interfacing electronics for DSP, a control rack has been developed. Measurement, calibration and integration of DSP derived current ripple information with power circuit is being carried out.

Photograph of control rack under development for line side active filter




Best viewed in 1024x768 resolution