| Paper | Title | Other Keywords | Page | ||
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| IT07 | Digital Signal Processing in Beam Instrumentation: Latest Trends and Typical Applications | diagnostics, instrumentation, betatron, closed-orbit, feedback | 30 | ||
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During the last decade digital signal processing has found its way into
the beam instrumentation arena, to become an essential part of several
beam diagnostic systems. In fact, the recent impressive hardware
performance improvement made it possible for functions once exclusively
accomplished by analogue methods, to be enhanced by the application of an
alternative digital approach. This is true to a point that the conversion
to digital processing has become inevitable. Factors that favour crossing
the border towards digital implementation are obviously speed as well as
precision, signal-to-noise ratio, dynamic range, stability of components
and configuration capability, together with the availability of powerful
and user-friendly development tools. Improvement in A/D conversion and
processing speed has allowed successfully developing digital feedback
loops and on-line diagnostics. The ascent of such digital techniques
generated a concurrent and parallel interest in digital signal processing
algorithms and in the use of the associated digital hardware components.
Current trends in beam diagnostics include using Digital Signal
Processors (DSPs), Field Programmable Gate Arrays (FPGAs), digital
receivers and fast digitizers. The talk reviews latest developments and
illustrates selected digital applications, relevant to the beam
diagnostic area.
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| CT03 | Beam Instrumentation for the Single Electron DAΦNE Beam Test Facility | diagnostics, instrumentation, linac, electron, positrons | 59 | ||
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The DAΦNE Beam Test Facility (BTF) has been successfully commissioned in
February 2002, and started operation in November of the same year.
Although the BTF is a beam transfer line optimized for single particle
production, mainly for high energy detectors calibration, it can provide
electrons and positrons in a wide range of multiplicity: between 1-1010,
with energies from a few tens of MeV up to 800 MeV. The large
multiplicity range requires many different diagnostic devices, from
high-energy calorimeters and ionization/fluorescence chambers in the few
particles range, to standard beam diagnostics systems. The schemes of
operation, the commissioning results, as well as the beam diagnostics are
presented.
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| PM06 | An Improved PLL for Tune Measurements | diagnostics, instrumentation, synchrotron, transverse-dynamics | 101 | ||
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The key element determining the dynamic performance of such a PLL is the
phase detector between the beam oscillation and the internal oscillation.
Most circuits use a quadrature phase detector, for which the high
frequency carrier at twice the excitation frequency is attenuated by a
low-pass circuit. The remaining ripple of this component contributes to
the bandwidth/noise performance of the PLL.
In this paper we propose an alternative solution for the filter, notably
an adaptive notch filter. We explain in detail design considerations and
the resulting improvements in PLL bandwidth and/or noise figure.
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| PM23 | Networked Attached Devices at SNS | diagnostics, instrumentation | 146 | ||
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The Spallation Neutron Source (SNS) diagnostic instruments at Oak Ridge
National Laboratory are based on the Network Attached Device (NAD)
concept. Each pickup or sensor has its own resources such as timing, data
acquisition and processing. NADs are individually connected to the
network, thus reducing the brittleness inherent in tightly coupled
systems. This architecture allows an individual device to fail or to be
serviced or removed without disrupting other devices.
This paper describes our implementation of the nearly 400 NADs to be
deployed. The hardware consists of rack-mounted PCs with standard
motherboards and PCI data-acquisition boards. The software environment is
based on LabVIEW and EPICS. LabVIEW supports the agile development
demanded by modern diagnostic systems. EPICS is the control system
standard for the entire SNS facility. To achieve high performance,
LabVIEW and EPICS communicate through shared memory.
SNS diagnostics are developed by a multi-laboratory partnership including
ORNL, BNL, LANL, and LBNL. The NAD concept proved successful during the
commissioning of the SNS front-end both at LBNL and ORNL.
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| PM29 | A Modular VME Data Acquisition System for Counter Applications at the GSI Synchrotron | monitoring | 164 | ||
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Particle counters perform the control of beam loss and
slowly extracted currents at the heavy ion synchrotron
(SIS) at GSI. A new VME/Lynx - PC/Linux based data
acquisition system has been developed to combine the
operating purposes beam loss measurement, spill analysis,
spill structure measurement and matrix switching
functionality in one single assembly. In this paper a
detailed PC-side software description is presented. To
achieve best system stability, the software has been
divided into time critical networking and data deploying
threads and low or normal priority interface tasks. Some
new abilities in the fields of data computation and
presentation are reported. A hardware description is
presented, in detail a programmable GSI-EVENT controller,
which is based on an ordinary 8 bit RISC microprocessor and
which has been integrated into the system, to synchronize
the data acquisition with the sophisticated “virtual
accelerator” timing at GSI. First experiences gained while
the commissioning of the system are discussed.
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| PT04 | Advantages Of Implementing Digital Receivers In Field Programmable Gate Arrays (FPGA) | diagnostics, industrial-accelerators, instrumentation, operational-performance | 175 | ||
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Today’s state-of-the-art FPGA technology allows designers to satisfy
almost any demand for high-speed data processing needed in DSP
applications and fast data transfers. Dedicated FPGA resources are used
in DSP applications to perform down conversion, filtering and data
formatting. New trends in system architecture favor serial data transfer
rather than parallel by using FPGA’s internal resources, BRAMs, high
speed serial IOs and hard core processors.
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| PT05 | Experience With Sampling Of 500 MHz Rf Signal For Digital Receiver Applications | diagnostics, industrial-accelerators, instrumentation, operational-performance | 178 | ||
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This article will present test results of a prototype system that was
built to evaluate feasibility of a direct sampling of a 500 MHz RF signal
for use in digital receiver applications. The system consists of a
variable gain RF front end, a fast analog to digital converter (ADC) and
a field programmable gate array (FPGA) providing glue-logic between the
ADC and a PC computer.
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| PT06 | Dynamic X-Y Crosstalk / Aliasing Errors of Multiplexing BPMs | instrumentation, diagnostics, pick-up, monitoring, operational-performance, feedback | 181 | ||
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Multiplexing Beam Position Monitors (BPM) are widely used for their
simplicity and inherent drift cancellation property. These systems
successively feed the signals of (typically four RF) pickups through one
single detector channel. The beam position is calculated from the
demultiplexed (base band) signal. However, as shown by this contribution,
transverse beam motion results in positional aliasing errors due to the
finite multiplexing frequency. Fast horizontal motion, for example, can
alias into an apparent, slow vertical position change. A thorough
analysis is presented and the impact of essential parameters such as the
multiplexing rate and the scanning pattern/sequence of classical 4-button
pickups is discussed.
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| PT08 | The LHC Orbit and Trajectory System | diagnostics, closed-orbit, instrumentation, LHC | 187 | ||
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This paper describes the definitive acquisition system selected for the
measurement of the closed orbit and trajectory in the CERN-LHC and its
transfer lines. The system is based on a Wide Band Time Normaliser (WBTN)
followed by a 10-bit ADC and a Digital Acquisition Board (DAB), the
latter developed by TRIUMF, Canada. The complete chain works at 40 MHz, so
allowing the position of each bunch to be measured individually. In order
to avoid radiation problems with the electronics in the LHC tunnel, all
the digital systems will be kept on the surface and linked to the
analogue front-ends via a single mode fibre-optic connection. Slow
control via a WorldFIP fieldbus will be used in the tunnel for setting
the various operational modes of the system and will also be used to
check power supply statuses. As well as describing the hardware involved,
some results will be shown from a complete prototype system installed on
four pick-ups in the CERN-SPS using the full LHC topology.
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| DW01 | Machine Protection And Interlock Systems
Session 1: Wednesday (11:15--13:00 Hrs) |
diagnostics, instrumentation, man-machine-interface, operational performance | 259 | ||
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The purpose of a MPS is to protect the equipment against abnormal beam
behaviour. High intense and high brilliant particle, photon and X-ray
beams are capable of causing significant damage to components in a
fraction of a second, i.e. too fast for any human reaction. The aim of
this session is to discuss existing and planned MPS with both their
specific and their general requirements. Among points to be reviewed: the
choice of sensors and components, the logic, the strategy, etc. in view
of the need for the MPS to be fail-proof. Some typical questions that
will be raised: What are the criteria for determining that an alarm
situation has been reached and what is the subsequent action of the
system? Very often the MPS may allow different beam modes, depending on
beam permit inputs. Which kind of beam modes exist and what are the input
signals? How are these systems integrated with the accelerator controls
and what is the impact on their operation?
This session will include a few very brief presentations of existing and
planned MPS' from different machines to illustrate the above questions
and to stimulate the subsequent discussion.
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| DW02 | Global Accelerator Network, Control Systems And Beam Diagnostics
Session 2: Wednesday (11:15--13:00 Hrs) |
diagnostics, instrumentation, man-machine-interface, operational performance | 260 | ||
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Falling funds force all accelerator centers to look for new sources of
financing and for the most efficient way of implementing new projects.
This very often leads to collaborations between institutes scattered
around the globe, a problem well known to big high energy physics
experiments. The collaborations working on big detectors e.g. for LHC
started thinking about detector acquisition and control systems which can
be remotely used from their respective home institutes with minimal
support on the spot.
This idea was taken up by A. Wagner from DESY for the TESLA machine, who
proposed the “Global Accelerator Network” (GAN) enabling users from
around the world to run an accelerator remotely.
Questions around this subject that immediately come to mind
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| DW03 | Beam Synchronous Timing Systems
Session 3: Wednesday (11:15--13:00 Hrs) |
diagnostics, instrumentation, fibre-optics | 261 | ||
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For many beam diagnostics purposes beam synchronous timing systems are
needed in addition to the timing systems supplied by the control systems
of the different accelerators. The demands and techniques of different
accelerator facilities will be discussed along the following aspects:
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