Download or read book Calibration of the Beam position Monitor System for the SLAC PEP II B Factory written by and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Beam-Position Monitors (BPM) for the PEP-II B Factory consist of four 1.5-cm diameter button style pickups mounted on the diagonals of the quadrupole vacuum chambers. Before installation of the vacuum chambers in the quadrupole assemblies, the electrical center of the BPMs is measured with respect to the mechanical center in a calibration test stand. In this paper the calibration test stand is described and the precision and accuracy of the calibrations are presented. After installation of the quadrupole assemblies in the PEP-II tunnel, the passive attenuation for each channel of the system is measured to preserve the accuracy of the calibration. Finally, the active electronics includes an onboard calibrator. Results for these portions of the calibration are presented.
Download or read book Some Solved Problems with the SLAC PEP II B Factory Beam Position Monitor System written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Beam-Position Monitor (BPM) system for the SLAC PEP-II B-Factory has been in operation for over two years. Although the BPM system has met all of its specifications, several problems with the system have been identified and solved. The problems include errors and limitations in both the hardware and software. Solutions of such problems have led to improved performance and reliability. In this paper the authors report on this experience. The process of identifying problems is not at an end and they expect continued improvement of the BPM system.
Download or read book Beam Position Monitor System for PEP II written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe the beam position monitor system built for PEP-II, the B-factory at SLAC. The system reports beam position for bunches of between 5 x 108 and 8 x 101° electron charges, either singly or as continuous streams of bunches every 4.2 ns. Resolution at full charge is to be better than 10 microns in a single turn. Higher resolution is available via on-board multi-turn averaging. The position signal is processed in a 20 MHz bandwidth around 952 MHz. This bandwidth, rather broader than that typical of RF position monitors, allows good resolution for low charge single bunches. Additional novel features include stringent control of return losses in order to minimize cross-talk between nearby bunches which may contain very different charges. The digitizing electronics is multiplexed between the two PEP-II storage rings. Design, construction, and installation experience, as well as first results with beam are presented.
Download or read book Beam Position Monitoring System for the Proposed Asymmetric B Factory at SLAC written by and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The beam position monitor system of the B Factory is drastically different from the actual PEP system. We present a description of the new configuration and list the features which have been adopted to make this system a highly reliable diagnostic tool. An electrode geometry is suggested, based on the maximum-acceptable power extracted from the beam, and the measurement resolution is estimated by assuming some practical bandwidth and the noise level. Finally, an estimate of the system precision is made by adding up what is expected to be the most significant systematic errors.
Download or read book Beam Instrumentation Workshop written by and published by . This book was released on 1998 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Instrumentation written by Alex H. Lumpkin and published by A I P Press. This book was released on 1997 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the May 1996 workshop, including tutorial, invited, and contributed papers. Subjects include a subpicosecond bunch duration measurement technique based on autocorrelation of coherent transition radiation, commissioning results of the APS storage ring diagnostics systems, bunch instabi
Download or read book Commissioning the Beam Diagnostics for the PEP II B Factory written by and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: PEP-II is a 2.2-km-circumference collider with a 2.1-A, 3.1-GeV positron ring (the Low-Energy Ring) 1 m above a 1-A, 9-GeV electron ring (the High-Energy Ring); both rings are designed for a maximum current of 3 A. The authors describe the beam diagnostics and present measurements from HER commissioning. The beam profile is measured using near-UV synchrotron light extracted by grazing-incidence mirrors that must withstand up to 200 W/cm. Normally 1,658 of the 3,492 buckets will be filled, and the charge must be equal within 2%. To measure the charge in each bucket, the sum signal from a set of 4 pickup buttons is digitized and averaged over 256 samples per bucket in every 60-Hz interval. The sum is them normalized to the ring current, measured by a DC current transformer. The 300 beam-position monitors per ring are multiplexed to share 171 processor modules, which use DPSs for recording positions over 1,024 turns and for calibration. For both diagnostics and machine protection, 100 photomultipliers with fused-silica Cherenkov radiators measure beam losses and can trigger a beam abort in case of high loss. For the ring tunes, signals from a set of 4 pickup buttons are combined into horizontal, vertical, and sum signals. Two signals are selected and downconverted into the range of a 10-MHz, 2-channel, programmable, DSP-based spectrum analyzer, connected over ethernet to the control room.
Download or read book The Logarithmic Beam Position Monitor written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern logarithmic amplifiers offer wide dynamic range, high bandwidth, good logarithmic conformance, and low cost making them attractive for beam position measurements. A log-ratio beam position monitor has been designed and built at SLAC for use at the PEP-II B-Factory. An integrated circuit logarithmic amplifier from Analog Devices, the AD8307, recovers the envelope of the 476 MHz harmonic of the beam signal. A log BPM board with two logarithmic and one differential amplifier performs the basic function of forming an output voltage proportional to the difference of the logarithms of the signal amplitudes on opposite electrodes. This voltage is approximately linear with beam position. For this application, the authors have limited the video bandwidth of the log amps to 50 kHz in order to remove fill pattern dependence. The log BPM board has an interface for testing and simulating beam offsets. The log BPM's were developed for a PEP-II ring protection chassis. Here the log BPM's function to identify dangerous orbit excursions. These excursions are signaled to a system, which can dump the beam. Two such chassis serve to protect the PEP-II rings.
Download or read book ANALYSIS OF THE CALIBRATION REQUIREMENTS FOR THE BOOSTER BEAM POSITION MONITORING SYSTEM written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calibration of KEKB Beam Position Monitors written by Kotaro Satoh and published by . This book was released on 1997 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of the Beam Position Monitor System of the Final Focus TestBeam written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Beam Position Monitor (BPM) system for the Final Focus Test Beam (FFTB) at SLAC is designed to meet challenging specifications in the areas of single-pulse resolution, ab initio installation accuracy, and time-stability of BPM electrical centroids. We review the tolerances on these quantities and the technical choices made to achieve same, and detail the results of several studies of the actual performance of the system. These results are then related to the BPM system requirements for a future high-energy ee− linear collider.
Download or read book Beam Position Monitor Calibration for the Advanced Photon Source written by and published by . This book was released on 1993 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the sensitivity and offset calibration for the beam position monitors (BPMs) using button-type pickups in the injector synchrotron, storage ring, and insertion devices of the Advanced Photon Source (APS). In order to reduce the overall offset and to isolate the error (r"100?m) due to the low fabrication tolerance in the extruded storage ring vacuum chamber, the electrical offset is minimized by carefully sorting and matching the buttons and cables according to the button capacitance and the characteristic impedances of the cable and the button feedthrough. The wire method is used for the sensitivity calibration, position-to-signal mapping, and measurement of resolution and long-term drift (r"1 mV) of the processing electronics. The processing electrons was also tested at Stanford Synchrotron Radiation Laboratory (SSRL) using a real beam, with results indicating better than 25?m resolution for the APS storage ring. Conversion between the BPM signal and the actual beam position is done by using polynomial expansions fit to the mapping data with absolute accuracy better than 25?m within ±5 mm square. Measurement of the effect of button mispositioning and mechanical inaccuracy of the extruded storage ring vacuum chamber, including deformation under vacuum, will be also discussed.
Download or read book A Two Bunch Beam Position Monitor written by and published by . This book was released on 2011 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new beam position monitor digitizer module has been designed, tested and tuned at SLAC. This module, the electron-positron beam position monitor (epBPM), measures position of single electron and positron bunches for the SLC, LINAC, PEPII injections lines and final focus. The epBPM has been designed to improve resolution of beam position measurements with respect to existing module and to speed feedback correction. The required dynamic range is from 5 x 108 to 1011 particles per bunch (46dB). The epBPM input signal range is from ±2.5 mV to ±500 mV. The pulse-to-pulse resolution is less than 2 [mu]m for 5 x 101° particles per bunch for the 12 cm long striplines, covering 30{sup o} at 9 mm radius. The epBPM module has been made in CAMAC standard, single width slot, with SLAC type timing connector. 45 modules have been fabricated. The epBPM module has four input channels X, X−, Y+, Y− (Fig. 1), named to correspond with coordinates of four striplines - two in horizontal and two in vertical planes, processing signals to the epBPM inputs. The epBPM inputs are split for eight signal processing channels to catch two bunches, first - the positron, then the electron bunch in one cycle of measurements. The epBPM has internal and external trigger modes of operations. The internal mode has two options - with or without external timing, catching only first bunch in the untimed mode. The epBPM has an on board calibration circuit for measuring gain of the signal processing channels and for timing scan of programmable digital delays to synchronize the trigger and the epBPM input signal's peak. There is a mode for pedestal measurements. The epBPM has 3.6 [mu]s conversion time.
Download or read book APCAL1 written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: APCAL1 is an applications program operational on the PEP MODCOMP IV computer for the purpose of converting beam position monitor (BPM) button voltage readings to x, y coordinates. Calibration information and the BPM readings are read from the MODCOMP IV data base. Corresponding x, y coordinates are written in the data base for use by other programs. APCAL1 is normally activated by another program but can be activated by a touch panel for checkout purposes.
Download or read book Offset Calibration of the Beam Position Monitor Using External Means written by and published by . This book was released on 1991 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Position Monitoring System for the Proposed Asymmetric written by Jean-Louis Pellegrin and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of the Button Beam Position Monitor for PEP II written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The beam position monitor (BPM) was designed to provide a robust UHV feedthru and a reliable electromagnetic sensor. Stringent resolution requirements at low beam currents, bunch parameters, along with mechanical and chamber requirements produced challenges in the electrical, thermal, and structural design of the BPM's. Numerical modeling and experimental analyses were used to optimize the design. The higher order modes (HOM's) and beam impedance were modeled using MAFIA. Measurements agreed with the calculated 1[Omega] transfer impedance at the 952 MHz signal processing frequency, and the first two HOM's found in MAFIA. Tests and analysis both showed the button signal power approaching 40 W. Temperature and stress distributions were analyzed using this power loading with ANSYS. An electronic grade CuNi was selected for the BPM to reliably weld into the copper chambers. Pin seal and compressive joints were considered for the insulator vacuum seals. Both glassy ceramic-to-metal and ceramic-to-metal seals were evaluated.
