Abstract:
The next generation electromagnetic
OK-5/Duke storage ring FEL wigglers require
three 3kA/70V power supplies with current
stability about 20 ppm and current ripples
less than 20ppm in their full operating
range. Duke FEL Laboratory acquired three
out-of-service thyristor controllable power
supplies (Transrex, 5kA/100V) which was built
almost 30 years ago. The existing archaic
firing circuit, lack of any output voltage
filtering and outdated DCCT, would not be
able to meet the above requirements.To
deliver the desirable high performance with
very limited funds, all three T-Rex power
supplies have been completely rebuilt in
house at DFELL. Modern high stability
electronic components and a Danfysik DCCT
with a high current stability have been used.
New symmetrical firing circuit, efficient
passive LC filter and reliable
transformer-coupled active filter are used to
reduce output current ripples to an
appropriate level. At the present time, the
first refurbished power supply in operation
since August, 2004 with good overall
performance. The power supply testing results
of this unit will also be presented in this
paper.