Abstracts Brochure - CERN

TUPCH165
TUPCH166
TUPCH167
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
COMPACT SINGLE-CHANNEL Ka-BAND SLED-II PULSE COMPRESSOR
S.V. Kuzikov, S.V. Kuzikov, M.E. Plotkin, A.A. Vikharev (Omega-P,
Inc.) J.L. Hirshfield (Yale University, Physics Department)
208
Basic studies of factors that limit RF fields
in warm accelerator structures require experiments
at RF power levels that can only
be produced from an intense drive beam, as
with CLIC studies, or using pulse compression of output pulses from the RF source. This latter approach is being
implemented to compress output pulses from the Yale/Omega-P 34-GHz magnicon to produce ∼100-200 MW, 100
ns pulses. A new approach for passive pulse compression is described that uses a SLED-II-type circuit operating
with axisymmetrical modes of the TE0n type that requires only a single channel instead of the usual double channel
scheme. This allows avoidance of a 3-dB coupler and need for simultaneous fine tuning of two channels. Calculations
show that with this device at 34 GHz one can anticipate a power gain of 3.3:1, and an efficiency of 66% for a 100 ns
wide output pulse, taking into account losses and a realistic 50-ns long 180 degrees phase flip.
Multi-megawatt Harmonic Multiplier for Testing High-gradient Accelerator Structures
V.P. Yakovlev (Omega-P, Inc.) J.L. Hirshfield (Yale University,
Physics Department)
Basic studies for determining the RF electric
and magnetic field limits on surfaces of materials
suitable for accelerator structures for
a future multi-TeV collider, and for the test-
ing of the accelerator structures and components themselves, require stand-alone high-power RF sources at several
frequencies, from 10 to 45 GHz. A relatively simple and inexpensive two-cavity harmonic multiplier at 22.8, 34.3, or
45.7 GHz is suggested to be the stand-alone multi-MW RF power source for this application. The design is based on
the use of an existing SLAC electron gun, such as the XP3 gun, plus a beam collector as used on the XP3 klystron.
RF drive power would be supplied from an 11.4 GHz, 50 or 75 MW SLAC klystron and modulator, and a second
modulator would be used to power the gun in the multiplier. Preliminary computations show that 64, 55, and 47
MW, respectively, can be realized in 2nd, 3rd, and 4th harmonic multipliers at 22.8, 34.3, and 45.7 GHz using 75 MW
of X-band drive power.
Modeling and Simulation Results of High-power HOM IOTs
The inductive output tube (IOT) continues
E.L. Wright, H.P. Bohlen (CPI)
to be the device-of-choice for terrestrial UHF
broadcast applications due to its high efficiency,
linearity, compactness, etc.; the same reasons that make this an attractive choice for scientific users. The IOT is
being considered for a growing number of accelerator programs requiring multi-kilowatts of continuous wave power,
at UHF and L-band frequencies. A number of vacuum electron device manufacturers are developing IOTs in support
of these programs. There are an equal number of accelerator programs that operate pulsed, requiring high peak
powers, where the only sources available are klystrons and MBKs. For these applications a higher-order mode IOT
(HOM IOT) shows great promise for the same reasons described above. Modeling and simulation results for devices
built to operate within the UHF and L-band frequency ranges will be shown, at power levels up to 5 MW.