Abstracts Brochure - CERN

TUPCH138
TUPCH139
TUPCH140
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
Longitudinal Beam Dynamics Optimization in the Booster Synchrotron of ITEP-TWAC Facility
The booster synchrotron of ITEP-TWAC Fa-
P.N. Alekseev, A.D. Milyachenko, V.P. Zavodov (ITEP)
cility (named UK) is used for acceleration of
carbon ions delivered by linear injector I3
with energy of 1.5 MeV/amu, up to the maximum energy of 400 MeV/amu. Speciality of longitudinal beam
dynamics in the UK ring arises from the super high local charge density at low bunching factor of a linac beam at
injection to the synchrotron ring, requiring debunching in the coasting beam, following the RF ramping for the ideal
adiabatic trapping and acceleration of the captured beam up to the maximum energy. Results of the low-level RF
hardware and software optimisation based on the longitudinal beam dynamics simulation and experiments with the
beam are presented.
Coupling Strength Calculation with Galerkin Method for Microtron Resonator
Galerkin method is used to calculate integral
V.G. Kurakin (LPI)
parameters of rf network consisting or regular
waveguide with the a resonator connected
to it. These parameters are standing wave ratio and cavity detuning due to waveguide coupling. In this method,
Maxwell equations are solved in quite usual method by expanding the fields in series of eigenfunctions. The key
feature of the method is the fact that eigenfunctions used are not forced to satisfy to the boundary conditions, and this
simplifies significantly the problem solution. The proofs of the method one can find in special literature, while here
we want emphasize that integral parameters for many cases may be calculated with predicted accuracy. Necessary
expressions for coupling area conductivities are derived followed by computer calculations. Formulae for a cavitywaveguide
coupling strength and for cavity detuning are derived as well. To the end, plots are presented thus
simplifying microtron resonator designing.
Studies of Thermal Fatigue Caused by Pulsed RF Heating
S.V. Kuzikov, N.S. Ginzburg, N.Yu. Peskov, M.I. Petelin, M.E.
Plotkin, A. Sergeev, A.A. Vikharev, N.I. Zaitsev (IAP/RAS) A.V.
Elzhov, A. Kaminsky, O.S. Kozlov, E.A. Perelstein, S. Sedykh, A.P.
Sergeev (JINR) I. Syratchev (CERN)
200
A future linear collider with a multi-TeV level
of energies of the collided particles in the
center of masses is naturally associated with
high frequencies and a high power RF level.
One of the interfering factors in this way is an
effect of copper damage due to multi-pulse
mechanical stress caused by high-power microwaves. In order to get new information about this effect, we started an
experiment with the test cavity fed by 30 GHz FEM oscillator (15-30 MW, 100-200 ns, 0.5 - 1 Hz). Now we finished the
second phase of this experiment where the test cavity was irradiated by 0.1 millions of RF pulses with temperature
rise ∼140 C in each pulse. The third phase is the experiment with 1 million pulses. In the next planned experiment
with 36 GHz magnetron (0.1-0.15 MW, 1-2 mks, 0.01 - 1 kHz) we are going to investigate the thermal fatigue in most
interesting for collider application region of temperatures (30-50 C). It is expected that these two experiments will
supply necessary statistical information for the developed theory of the thermal fatigue in order to extrapolate lifetime
numbers to other values of the temperature rise and pulse duration.