CERN, Geneva
During the 2008 LHC injection synchronisation tests and the subsequent days with circulating beam, the majority of the LHC beam instrumentation systems were capable of measuring their first beam parameters. This included the two large, distributed, beam position and beam loss systems, as well as the scintillating and OTR screen systems, the fast and DC beam current transformer systems, the tune measurement system and the wire scanner system. The fast timing system was also extensively used to synchronise most of this instrumentation. This presentation will comment on the results to date, some of the issues observed and what remains to be done for the next LHC run.
LBNL, Berkeley, California
The 13th edition of the Beam Instrumentation Workshop (BIW08) took place at the Granlibakken Conference Center on the beautiful shores of Lake Tahoe in California during the first week of May 2008. About 130 participants registered for the workshop. Included in the program during the three and a half days were three tutorials, eight invited and seven contributed oral presentations, and more than 50 poster contributions. A discussion group session, and the vendor exhibition simultaneously held with the single day poster session, afforded many opportunities for informal discussion and idea exchange between attendees. During the workshop, the 2008 Faraday Cup Award that recognizes innovative achievements in beam diagnostics was also presented. In this talk, I will present the highlights from BIW08. The overall quality of the contributions was notably high, which made the selection of the topics for this talk quite difficult. Although I endeavored to produce a balanced choice of highlights, the final list is surely incomplete due to time limitations of the talk, and also it unavoidably reflects my personal point of view and preferences.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
BERGOZ Instrumentation, Saint Genis Pouilly
An alternative to a BPM with a continuous detector/ADC clock distributed from a synchronised with beam master generator is a self-synchronised BPM where the clock is manufactured from the beam signal itself. In a single-shot BPM of such kind [1], which is being designed for the EMMA Accelerator, the ADC should execute several subsequent fast rate measurements with a clock burst triggered by the bunch on each turn. We investigated a work of some fast pipeline-type ADCs suitable for BPMs, in a burst regime where a minimal burst length is decided by the ADC latency. The results did show that pipeline-type ADCs a main merit of whose is a high precision are usable in single-shot BPMs. We discuss how to prevent some ADC resolution deterioration that typically occurs at first samples, and to attain an ultimate ADC resolution in a single-shot BPM.
[1] A. Kalinin, Towards Sub-Micrometer Resolution of Single-Shot Strip Line BPM, EUROTeV-Report-2008-056.
YerPhI, Yerevan
BERGOZ Instrumentation, Saint Genis Pouilly
ANL, Argonne, Illinois
YSU, Yerevan
The Vibrating Wire Monitor (VWM) was developed for precise transversal profiling/monitoring of charged particle/photon beams. The extremely high sensitivity of VWM is achieved by sensitivity of wire natural oscillation frequency to wire temperature. Due to the rigidity of the wire support structure, the VWM is also sensitive to the environmental parameters. In this paper, it is shown that the main parameter of influence is the ambient temperature. The magnitude and character of this influence is investigated along with the effect of electromagnetic interference on the VWM electronics in an accelerator environment.
GSI, Darmstadt
At the GSI Linac and transfer lines several Beam Induced Fluorescence Monitors (BIF) for transverse profile determination are installed. The non-intercepting measurement principle is based on the excitation of residual gas molecules by the beam and the detection of the fluorescence photons with image intensified cameras. This allows simultaneous profile determination at multiple positions without beam disturbance. The software ProfileView is a data acquisition system to visualize and record the profiles of several BIF monitors along the beamline. One BIF monitor comprises two image intensified cameras with remote irises, timing interface, gas pressure control and remote reset functionality. The basic functions needed for daily operation are combined in an easy-to-use graphical user interface. Beside this 'operator mode' an 'expert mode' can be called by advanced users to control every hard- or software parameter of the whole system separately. This contribution describes the software design and its realization for communication and data display.
IMP, Lanzhou
This paper gives the detectors used for slowly extracted heavy ions from CSR. The beam profiles are measured with viewing screens and anode-striped ion-chambers. The currents are determined with scintillators and ion-chambers. The signal processing system and the measurement results are also presented.
DELTA, Dortmund
TU Dortmund University, Dortmund
Orbit stability at the 1.5 GeV electron storage ring DELTA is currently achieved via a global slow orbit feedback system at a data acquisition rate of 10 Hz. The system is based on analog Bergoz MX-BPMs and I-Tech Libera digital BPMs. In order to enhance the precision of the slow position measurement and in preparation for a global fast orbit feedback at a 10 kHz data acquisition rate we developed an FPGA based digital frontend for the MX-BPMs. The prototype module is taking orbit data from 4 Bergoz MX-BPMs, clocked to 40 kHz, at a rate of 10 kHz while averaging over 4 samples per clock cycle. The digitized data is distributed via the Diamond Communication Controller [*] formerly only available for Libera BPMs. Precision, fault tolerance and easy maintenance are the key aspects of this system. First operational tests in the storage ring showed that the system reveals the desired capabilities. The paper will give an overview on the layout of the FPGA-based system, will report on the results with beam and will show prospects for the further use at DELTA.
*I. S. Uzun et al., "Initial Design of the Fast Orbit Feedback System for Diamond Light Source", Proc. 10th ICALEPCS
INFN/LNF, Frascati (Roma)
ELETTRA, Basovizza
The single pass functionality available in the recent release of the Libera Brilliance software, takes particular interest when compared with requirements of FEL machines, that need stable and precise control of the beam trajectory throughout Linacs and transfer lines in order to meet the stringent beam quality and transverse position constraints inside undulators. Results from tests performed on Libera with beam from ELETTRA, SPARC and DAΦNE, operating in Sincrotrone Trieste and LNF Frascati, are reported to characterize the resolution of single shot transverse beam position measurements.
CERN, Geneva
Many beam instrumentation signals of large circular accelerators are in the kHz range and can thus be digitised with powerful high resolution ADCs. A particularly large dynamic range can be achieved if the signals are analysed in the frequency domain. This report presents a system employing audio ADCs and FPGA-based spectral analysis, initially developed for tune measurement applications. Technical choices allowing frequency domain dynamic ranges beyond 140 dB are summarised.