Abstracts Brochure - 2nd International Particle Accelerator Conference

een probed, the injection energy (450 GeV) and the
collision energy (3.5 TeV). The results obtained are
presented. For high LHC bunch intensities the
Beam-Beam force is strong enough to expect orbit
effects if the two beams do not collide head-on but
with a crossing angle. As a consequence the closed
orbit changes. The closed orbit of an unperturbed
machine with respect to a machine where the Beam-
Beam force become more and more important has
been studied and the results are presented.
Sub Classification: D02 Non-linear Dynamics -
Resonances, Tracking, Higher Order
Poster Panel 55
ID: 3038 - WEPC068
The Spin Aberration of Polarized Beam in the
Electrostatic Ring, Yurij Senichev, Rudolf Maier,
Denis Zyuzin (FZJ, Jülich) - Analytical solution for
components of the spin vector is recorded in the
form of transform matrixes for different electrostatic
elements. These matrixes are used for numerical
simulation of spin motion in the electrostatic ring for
arbitrary particle in a similar way to phase motion.
By this method we investigate behaviour of spin at
different initial spin orientation and different beam
energy. For a beam with nonzero transverse
emittance at particle passage through a non-uniform
electric field, for example an electric focusing lens,
the orientation of a spin vector becomes function of
phase variables that leads to the spin aberration. We
investigate this process analytically and numerically.
Sub Classification D02 Non-linear Dynamics -
Resonances, Tracking, Higher Order
Poster Panel 56
ID: 3778 - MOPS029
Experiments with a Fast Chopper System for
Intense Ion Beams, Hannes Dinter, Martin Droba,
Marcel Lotz, Oliver Meusel, Ilja Mueller, Daniel
Noll, Ulrich Ratzinger, Kathrin Schulte, Christopher
Wagner, Christoph Wiesner (IAP, Frankfurt am
Main) - Chopper systems are used to pulse charged
particle beams. In most cases, electric deflection
systems are used to generate beam pulses of defined
lengths and appropriate repetition rates. At high
beam intensities, the field distribution of the chopper
system needs to be adapted precisely to the beam
dynamics in order to avoid aberrations. An
additional challenge is a robust design which
guarantees reliable operation. For the Frankfurt
Neutron Source FRANZ, an E×B chopper system is
being developed which combines static magnetic
deflection with a pulsed electric field in a Wien filter
�
17
configuration. It will generate proton pulses with a
flat top of 50 ns at a repetition rate of 250 kHz for
120 keV, 200 mA beams. For the electric deflection,
pre-experiments with static and pulsed fields were
performed using a helium ion beam. In pulsed mode
operation, ion beams of different energies were
deflected with voltages of up to ±6 kV and the
resulting response was measured using a beam
current transformer. A comparison between
experiments and theoretical calculations as well as
numerical simulations are presented.
Sub Classification: D04 High Intensity in Linear
Accelerators
Poster Panel 57
ID: 2706 - MOPS034
Progress on Space Charge Compensation Study
in Low Energy High Intense H+ Beam,
Pengnan Lu, Zhiyu Guo, Shi Xiang Peng, Zhi
Zhong Song, Jin Xiang Yu, Zhong Xi Yuan, Jie
Zhao (PKU/IHIP, Beijing), YingJun Ma (CIAE,
Beijing), Haitao Ren (Graduate University, Beijing)
- This article draws emphasis on the correlation
between the space charge compensation (SCC) and
the beam quality in different operation conditions.
Theoretical improvement has been made to the
model of Particle Life Span � PLS � which was
developed in Peking University. In the improved
model the thermal motion of electrons is considered
with relaxed assumptions. And more detailed
boundary conditions are used in calculating particle
distribution. Based on the theoretical analysis three
series of experiments have been conducted. Firstly,
transport efficiency beam intensity, beam profile and
emittance variation are quantitatively studied
together with energy spectra of Compensation Gas
Ions (CGI) in 50KeV/100mA H+ beam. Secondly,
to explore better SCC efficiency we tested the
function of ring electrodes in inhibiting electron
escape. Moreover both Ar and Kr were used as
comparison of different compensation gas. Lastly,
SCC with pure additional electrons from a
transverse electron gun is preliminarily
experimented. All results will be presented and
discussed in the text for seeking the best
circumstances in SCC dominated low energy high
intensity ion beams.
Sub Classification: D04 High Intensity in Linear
Accelerators