Abstracts Brochure - CERN

THPCH132
THPCH133
THPCH134
29-Jun-06 16:00 - 18:00 THPCH — Poster Session
for SNS. The kicker control system is integrated
using EPICS and has been used for supporting SNS ring commissioning. In this paper we describe the control
system functions and timing system integration for the SNS injection and extraction kicker systems. We also present
the system performance results from ring commissioning and upgrade plan derived from our commission experience.
EPU Assembly Based on Sub-cassettes Magnetic Characterization
A procedure to speed up the magnetic field
G. Tosin, R. Basilio, J.F. Citadini, M. Potye, X.R. Resende (LNLS) correction of an EPU type undulator is proposed
and its results are shown. Such procedure
consists in segmenting each one of the four magnetic blocks linear arrays (cassettes) in seven sub-cassettes
and making their individual magnetic and mechanical characterization. One theoretical perfect sub-cassette, which
is composed of four segments per period in Halbach configuration, is taken as the standard field profile. The peak
fields and the fields integrated in each semi-period of one sub-cassette are chosen to be the optimization parameters.
The magnetic blocks are displaced (virtual shims) to minimize the difference of the optimization parameters
between the sub-cassette magnetic measurement and the standard profile. The sub-cassette magnetic measurements
are performed with Hall probes, using the same bench employed in insertion devices characterization.
Conceptual Design of an EPU for VUV Radiation Production at LNLS
G. Tosin, R. Basilio, J.F. Citadini, R.T. Neuenschwander, M. Potye,
X.R. Resende, M. Rocha, P.F. Tavares (LNLS)
426
We describe the magnetic and mechanical
design of an elliptically polarizing undulator
(EPU) currently under construction at the
(Brazilian Synchrotron Light Source - LNLS).
The device is designed to cover the photon flux in the range from 100eV to 1000eV (124Å a 12.4 Å), allowing linear,
elliptical and circular polarizations. With this device it is possible to reach absorption edges of several elements such
as Si, S, Br, C, N, O, Fe, F, Cl and to measure magnetic dichroism. The EPU’s magnetic design is conventional, and
field corrections are done by means of virtual shims, with horizontal and vertical displacements. Each one of the four
magnetic blocks linear arrays (cassettes) is segmented in seven sub-cassettes. The separate magnetic measurement
of each sub-cassette allows corrections of the magnetic field profile to be made before final assembly and makes the
verification of mechanical tolerances easier and faster, decreasing the expected time that will be spent in the magnetic
tuning of the device. The mechanical structure is composed of a C-Frame, gap and phase actuators. The gaps actuators
and phase actuators use absolute encoders and bias with springs to eliminate backlash.
Development of Insertion Device Magnetic Characterization Systems at LNLS
This paper describes a set of magnetic mea-
G. Tosin, R. Basilio, J.F. Citadini, M. Potye (LNLS)
surement systems employed in the development
of insertion devices at LNLS (Brazilian
Synchrotron Light Source). They are: rotating coil (which can also operate as a flip-coil), spatial field mapping
using Hall probes and parallel coils (Helmholtz configuration) for magnetic blocks characterization. Although such
techniques are well established, strict specifications imposed by the beam dynamics on the magnetic field quality, led
to a detailed analysis of their sources of error and their minimization. All three systems have already been tested and
showed excellent accuracy and repeatability when compared to typical values found in the literature.