Abstracts Brochure - CERN

THPCH — Poster Session 29-Jun-06 16:00 - 18:00
with the code HOMDYN taking into account the superposition of incident and reflected laser pulses as well as space
charge fields. Under this conditions the emittance degradation is negligible, as predicted by analytical methods, but
a longitudinal charge modulation occurs on the scale of the laser wavelength, in case of oblique incidence, driven
by the longitudinal component of the laser field. Preliminary simulations up to the photoinjector exit show that
charge modulation is transformed into energy modulation via the space charge field, which may produce enhanced
microbunching effects when the beam is further compressed in a magnetic chicane.
Wire Compensation of Parasitic Crossings in DAFNE
Long-range beam-beam interactions (parasitic
crossings) are one of the main luminosity
performance limitations for the Frascati
e + e − Phi-factory DAFNE. In particular, the
M. Zobov, D. Alesini, C. Milardi, M.A. Preger, P. Raimondi (INFN/
LNF) D.N. Shatilov (BINP SB RAS)
parasitic crossings (PC) lead to a substantial lifetime reduction of both beams in collision. This puts a limit on the
maximum storable current and, as a consequence, on achievable peak and integrated luminosity. In order to alleviate
the problem numerical and experimental studies of the PC compensation with current-carrying wires have been
performed at DAFNE. Two such wires have been installed at both ends of the KLOE interaction region. Switching on
the wires in accordance with the numerical predictions, improvement in the lifetime of the "weak" beam (positrons)
has been obtained at the maximum current of the "strong" one (electrons) without luminosity loss. In this paper we
describe the PC effects in DAFNE, summarize the results of numerical simulations on the PC compensation with the
wires and discuss the experimental measurements and observations.
Design of the Proton Linac for the SPES-1 Project
The SPES-1 is a superconducting proton injector
for the SPES Linac. It accelerates a
10 mA proton beam produced by TRASCO-
SPES RFQ up to 20 MeV. It operates in a con-
E. Fagotti, G. Bisoffi, M. Comunian, A. Palmieri, A. Pisent (INFN/
LNL)
tinuous wave regime (CW) and is designed for a maximum efficiency in the transmission of intense beams. The
main period consists of a warm magnetic doublet for transverse confinement and a four gaps ladder superconducting
cavity for acceleration. This paper presents the beam dynamics studies associated with this design.
Study of Particle Losses Mechanism for J-PARC Main Ring
Detailed understanding as well as confidence
in simulation modeling of long-term effects A.Y. Molodozhentsev, M. Tomizawa (KEK)
(∼ 100’000 turns) of high intensity proton
beam is crucial for Main Ring (MR) of the J-PARC project, where it is necessary to hold the high-intensity beam
over typically ∼ 2 sec with a loss level less than 1%. The major focus of such study is the combined effect of space
charge and nonlinear resonances and its impact on halo formation and/or beam loss. In frame of this report, the
tracking results for the injection process including realistic representation of the ring’s focusing structure are discussed.
Optimization of the working point during the injection process is presented. The halo formation and particle
losses during the injection and acceleration for MR have been estimated for realistic magnetic field errors.
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