IGBT's, pulsed power (was Re: Waveguide TC)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Greg Leyh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <lod-at-pacbell-dot-net>


>Original poster: "David Sharpe <sccr4us-at-erols-dot-com>
>
>[snip]
>Stanford Linear Accelerator (SLAC) is one of the highest power
>pulsed linear accelerators in this area, Greg Leyh may have some additional
>comments concerning that system.  I'be been watching their ground breaking
>work with IGBT's and pulsed power klystron drivers with great interest... and
>hoping for several technical breakthroughs that can be utilized at our end
>of the power spectrum.

SLAC is engaged in the machine design of many subsystems
for the Next Linear Collider, including the pulsed power
modulators that will feed the 8000 or so 75MW x-band klystrons.

Each of the 1000 or so modulator stations needs to generate a
500kV, 2000A, 3uS pulse, at 120BPS.  Originally based on hydrogen
thyratrons, the current modulator design now incorporates a
novel 'fractional turn' transformer geometry driven by an array
of 156 3300V, 2000A IGBT's.

The IGBT's have been somewhat problematic, given that they are
being operated in a very un-spec'd area of their parameter space.

Here's a summary of the IGBT development that's been done to date:
http://www-group.slac.stanford.edu/esd/default.htm

IGBT's hold a great deal of promise for other pulsed power
applications, as well.  They might be the right answer for
medium-scale coils; it will depend largely on the requirements
for dI/dt and the primary voltage.  For larger coils, where dI/dt
is not an issue and where primary voltage and RMS current
capability is critical, it appears that laser-triggered silicon
might very well be the answer.