60
Plasma
Switch for 11.4 GHz Active Sled-II RF Pulse Compressor--Omega-P,
Inc., 202008 Yale Station, Suite 100, New Haven, CT
06520-2008; 203-458-1144
Dr.
Jay L. Hirshfield, Principal Investigator,
Dr.
George P. Trahan, Business Official,
DOE
Grant No. DE-FG02-02ER83540
Amount:
$750,000
High pulsed radio frequency (RF) power, needed for a
future electron-positron collider such as NLC, will require RF pulse
compression, for which a number of approaches are currently under study.
Active RF pulse compression can, in principal, provide greater
flexibility in compressor design than passive compression, because higher
compression ratios at higher efficiency can be achieved.
This project will develop a plasma switch for an active SLED-II RF pulse
compressor with a compression ratio greater than 8:1 and efficiency greater than
75%. The plasma switches will be
used with resonance structures having a reflection coefficient that can be
rapidly shifted during the RF pulse from a klystron.
Changing both the reflection coefficient of the switch and the phase of
the klystron output will allow high compression ratios with high efficiency.
In Phase I, three versions of an X-band resonance structure were
designed to couple RF power from a klystron into a pair of delay lines and
thence, upon switching, into an accelerator structure.
Low-power cold tests were conducted, and, for one version, 70 ns RF
pulses were produced with power gains up to 15:1. Improved
plasma switch tube concepts were developed for implementation during Phase II,
to allow operation at peak power levels exceeding 400 MW, with good
pulse-to-pulse reproducibility. In
Phase II, engineering designs for the RF structures and associated plasma
switches will be completed, and plasma discharge tubes of both quartz and
ceramic will be evaluated. Optimized
plasma switches will be built and installed on the SLAC dual-mode X-band
resonant delay lines for testing at high power, with the aim of producing 400 ns
RF pulses with peak power >400 MW and efficiency >75%.
Commercial Applications and Other Benefits
as described by awardee: The RF
plasma switches should be suitable for use in a future electron-positron
collider such as the NLC. Thousands
of these switches would be required, constituting a potential market of several
tens of millions of dollars. Other
markets for such switches could exist in advanced radar systems.