Abstracts Brochure - CERN

TUPCH033
TUPCH034
TUPCH035
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
Automated Beam Optimisation and Diagnostics at MAMI
M. Dehn, H. Euteneuer, F.F. Fichtner, A. Jankowiak, K.-H. Kaiser,
W.K. Klag, H.J. Kreidel, S.S. Schumann, G.S. Stephan (IKP)
170
At the Institut fur Kernphysik (IKPH) of
Mainz University the fourth stage of the
Mainz Microtron (MAMI), a 855MeV to
1500MeV Harmonic Double Sided Microtron
(HDSM), is now on the verge of first operation*. To provide an automated beam optimisation, low-Q-TM010 and
TM110 resonators at each linac of the three cascaded RTMs and the two linacs of the new HDSM are used. These
monitors deliver position, phase and intensity signals of each recirculation turn when modulating the beam intensity
with 12ns-pulses (diagnostic pulses, max. rep. rate 10kHz). For operating the HDSM an extended system for
displaying and digitising these signals was developed. High-bandwidth ADCs allow very comfortable to analyse,
calibrate and automatically optimise the beam positions and phases during operation. The system is also used to
adjust the transversal and longitudinal focussing according to the design parameters. Synchrotron radiation monitors,
providing beam sizes and positions out of the bending magnets for each turn and on the entrance and exit of the linac
axis, were a very helpful tool for beam-matching between the RTMs. Therefore a similar system was planned and
constructed for the HDSM.
*A. Jankowiak et al. “Status Report on the Harmonics Double Sided Microtron of MAMI C”, this conference.
Different Methods for Transverse Phase Space Characterization at PITZ 2
The goal of PITZ is to develop and to opti-
L. Staykov (DESY Zeuthen)
mize high brightness electron sources suitable
for SASE FEL operation. The upgraded
PITZ facility consists of an L band RF gun and a booster cavity, the latter capable to boost the electron beam energy to
about 13 MeV. The nominal value for the bunch charge is 1 nC and the optimization effort goes toward minimizing
the beam emittance where the minimum is expected to be about 1 pi.mm.mrad. In this work two basic methods for
emittance measurements, namely the quadrupole scan and the single slit scan are compared. Their performance in
the PITZ parameter space is evaluated trough extensive ASTRA* simulations. The sources of uncertainty relevant to
each type of measurement are analyzed in details.
*K. Floetmann - ASTRA, http://www.desy.de/mpyflo
Fine Spatial Beam Loss Monitoring for the ISIS Proton Synchrotron
Beam loss detection at the ISIS synchrotron is
S.J. Payne, C.M. Warsop, S.A. Whitehead (CCLRC/RAL/ISIS) achieved using a series of 3 and 4 metre long
argon gas ionisation tubes placed around the
inside track of the main ring and along the injector and extraction sections. Even with this level of diagnostics problems
have occurred, for example, inside a main dipole within the accelerator ring where small concentrated areas of loss
have resulted in severe damage to the RF shield. This type of loss cannot be easily resolved using the conventional
argon gas system due to the length of the detectors and their distance from the vacuum vessel (around 2m). We
report here the development of a compact beam loss monoitoring system which has been installed inside a dipole
between the vacuum vessel and the main body of the dipole. The system comprises of six 150 sq. cm. (BC408)
plastic scintillators connected to photo-multiplier tubes via fibre optic bundles. Measurements taken demonstrate
that the new system can easily resolve complex beam loss patterns along the dipole while remaining robust to the
high radiation environment. We also report here details of our PXI based data collection and display system.