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 What Does a Beam Position Monitor Monitor written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam position monitors have been used progressively at SLAC requiring higher and higher accuracy. The assumption is always made that a beam position monitor measures the position of the bunch at the geometrical center between the electrodes at the time of passage of the bunch. There is no experimental evidence either with beams or with wires carrying current pulses that this assumption is incorrect. Yet as energies increase and as the required accuracy moves into the micron range it appears useful to look at this fundamental assumption.

Download or read book Beam Position Monitor for RHIC written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Beam Position Monitor System for Storage Rings written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam position monitors (BPM) for synchrotron light storage rings usually consist of beam pickup electrodes, coaxial relays and a narrowband receiver. While accurate, these systems are slow and of limited use in the commissioning of an accelerator. A beam position monitor is described which is intended to be a principal diagnostic during debug and routine running of a storage ring. It is capable of measuring the position of a single bunch on the first or nth orbit to an accuracy of a few percent. Stored beam position is more accurately measured with averaging techniques. Beam position changes can be studied in a bandwidth from DC to a few MHz. The beam monitor electronics consist of a separate amplification, detection, and sampling channel for each beam pickup electrode. Fast switches in each channel permit selection of the nth turn for measurement (single bunch mode). A calibration pulse is injected into each channel after beam measurement to permit gain offsets to be measured and removed from the final data. While initially more costly than the usual beam position monitor system, this sytem will pay for itself in reduced storage ring debug and trouble shooting time. 5 refs., 5 figs.

Download or read book Characterization of Beam Position Monitors for Measurement of Second Moment written by and published by . This book was released on 1995 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dual-axis beam position monitor (BPM) consists of four electrodes placed at 90° intervals around the probe aperture. The response signals of these lobes can be expressed as a sum of moments. The first order moment gives the centroid of the beam. The second order moment contains information about the rms size of the beam. It has been shown previously that the second order moment can be used to determine beam emittance. To make this measurement, the authors must characterize the BPM appropriately. The approach to this problem is to use a pulsed wire test fixture. By using the principle of superposition, they can build up a diffuse beam by taking the signals from different wire positions and summing them. This is done two ways: first by physically moving a wire about the aperture and building individual distributions, and, second, by taking a two dimensional grid of wire positions versus signal and using a computer to interpolate between the grid points to get arbitrary wire positions and, therefore, distributions. The authors present the current results of this effort.

Download or read book Note on Improving the Design of the HEM11 Mode Beam Position Monitor written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The HEM11 wave BPM has many advantages. It uses actual accelerator cavities to monitor beam position and does not occupy additional space on the beam line. Also it directly monitors beam position within the accelerating section. Calculations indicate the HEM11 BPM has high sensitivity. It can be used in the colliding region of SLC as an independent device for monitoring beam position with accuracy on the order of micrometers. In this application it is possible to optimize the design of the HEM11 mode BPM, and make it more effective and even smaller. 5 refs., 10 figs.

Download or read book Beam Position Monitor written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book AN X BAND CAVITY FOR A HIGH PRECISION BEAM POSITION MONITOR written by R. Johnson and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The next generation of accelerators will require increasingly precise control of beam position. For example designs for the next linear collider require beam-position monitors (BPMs) with 300 nm resolution. The accelerator designs also place difficult requirements on accuracy and stability. To meet these requirements a cavity BPM operating at 11.424 GHz was designed. The BPM consists of two cavities: an xy-cavity tuned to the dipole mode and a phase cavity tuned to the monopole mode. The xy-cavity uses a novel-coupling scheme that (in principal) has zero coupling to the monopole mode. This report will present the mechanical design, simulations, and test results of a prototype BPM. In addition BPM designs with even higher precision will be discussed.

Download or read book Parasitic Mode Losses Versus Signal Sensitivity in Beam Position Monitors written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A beam position monitor (BPM) for a storage or damping ring may be subject to heating problems due to the parasitic mode (PM) losses, beam interception and synchrotron radiation interception. In addition, high PM losses can cause beam instabilities under some conditions. Recessing and/or masking the BPM may increase the PM losses in the process of solving the latter two problems. This paper presents three complementary methods for estimating the PM losses and for improving the design of a stripline directional coupler type of BPM: bench measurements, computer modeling (TBCI), and an equivalent circuit representation. These methods lead to a decrease in PM losses without significant reduction in output signal for the north SLC damping ring BPMs.

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 Readout and Control in the SLC Linac written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A beam position monitoring system has been implemented in the first third of the SLC linac which provides a complete scan of the trajectory on a single beam pulse. The data is collected from the local micro-computers and viewed with an updating display at a console or passed on to application programs. The system must operate with interlaced beams so the scans are also interlaced, providing each user with the ability to select the beam, the update rate, and the attenuation level in the digitizing hardware. In addition each user calibrates the hardware for his beam. A description of the system architecture will be presented. 6 refs., 4 figs.

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.

Download or read book A Simple Beam Position Monitor System for CEBAF written by and published by . This book was released on 1988 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: CEBAF is a recirculating linac where the beam passes several times through the linac structures. As a result, up to five beams of different energies may be present in the same linac vacuum chambers simultaneously. One method of distinguishing between the beams involves modulating the current for a time interval of less than one revolution period. In this paper, a very simple low cost beam position monitor system based on the detection of this modulation is presented. Initial results indicated that 1mm displacements for beam currents of 1 micro-amp can be measured. With the incorporation of several improvements to the present monitor design, the sensitivity is expected to be increased to 1 mm for a 100 nA beam.

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 Performance of the Beam Position Monitor for the Advanced Photon Source written by and published by . This book was released on 1995 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self Triggered Single Pulse Beam Position Monitor written by and published by . This book was released on 1993 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Beam Position Monitor System for Proton LINAC for FAIR written by Mohammed Heneen Almalki and published by . This book was released on 2015 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: