摘要:

The PIN-Diode Beam Loss Monitors (BLMs) developed at DESY were the subject of the Faraday Cup Award 2000. This talk presents a general overview of the system at HERA, its use and the experience with these BLMs at DESY. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342576

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Beam position measurements can be used to precisely calibrate accelerator optics as well as calibrate the beam position monitors themselves. Beam-based alignment techniques are essential with short wavelength FELs for aligning quadrupoles, calibrating BPM offsets, and achieving tight tolerances on the electron trajectory. Model independent analysis of pulse by pulse trajectories can locate error sources in linear accelerators. Turn-by-turn BPM measurements of betatron oscillations in storage rings provide a precise diagnostic of linear optics—both uncoupled and coupled. Analysis of the measured orbit response matrix is another powerful technique for debugging and correcting storage ring optics and coupling. This tutorial will give an introduction to these various beam-based techniques. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342577

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

At the first sight the problem to determine the beam position from the ratio of the induced charges of the opposite electrodes of a beam monitor seems trivial, but up to now no unique solution has been found that fits the various demands of all particle accelerators. The purpose of this paper is to help “instrumentalists” to choose the best processing system for their particular application, depending on the machine size, the input dynamic range, the required resolution and the acquisition speed. After a general introduction and an analysis of the electrical signals to be treated (frequency and time domain), the definition of the electronic specifications will be reviewed. The tutorial will present the different families in which the processing systems can be grouped. A general description of the operating principles with relative advantages and disadvantages for the most employed processing systems is presented. Special emphasis will be put on recent technological developments based on telecommunication circuitry. In conclusion, an application example will show how to choose the correct solution for a particular case. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342578

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The use of digital signal processing techniques in beam diagnostics is reviewed, with the desire to provide an understanding of the match between diagnostic needs and DSP solutions. Beginning with a short introduction to the formalism of Digital Signal Processing, the advantages of using DSP for instrumentation is linked to the choice of DSP algorithms and DSP architecture. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342579

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

This paper is a tutorial level review covering a wide range of aspects related to charged particle beam current measurement. The tutorial begins with a look at the characteristics of the beam as a signal source, the associated electromagnetic fields, the influence of the typical accelerator environment on those fields, and the usual means of modifying and controlling that environment to facilitate beam current measurement. Short descriptions of three quite different types of current monitors are presented and a quantitative review of the classical transformer circuit is given. Recognizing that environmental noise pick-up may present a large source of error in quantitative measurements, signal handling considerations are given considerable attention using real-life examples. An example of a successful transport line beam current monitor implementation is presented and the tutorial concludes with a few comments about signal processing and current monitor calibration issues. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342580

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The MIT-Bates Linear Accelerator Center is an electron scattering facility for basic research in medium energy nuclear physics. It consists of a 1 GeV 2.856 GHz linear accelerator and recirculator, two main experimental halls, and the 190 m circumference South Hall Ring (SHR). Both polarized and unpolarized electron sources are available. The SHR can be operated in storage mode, providing high current beam for use with internal targets, or in pulse-stretcher mode, using resonant extraction to deliver high duty factor beam to fixed target experiments. Spin control is installed for both stored and extracted beams. Extensive beam diagnostics are available on all beamlines. These include beam position monitors with multiple data acquisition modes, beam current monitors covering several orders of magnitude in current and frequency response, wire scanners, polarimeters, and so on. Details and applications of the Bates instrumentation are presented. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342581

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Instrumentation concepts for the Very Large Hadron Collider (VLHC) are discussed. Different design concepts for the VLHC result in substantially different instrumentation layouts. High field, cold bore magnets have instrumentation requirements very similar to the SSC and LHC. In contrast, the low field warm bore “transmission line” magnets have very sparse instrumentation and the long magnet length allows the cable plant to be preinstalled on the magnets. Specialized beam instrumentation concepts including permanently sealed semi-rigid coax BLMs and distributed coupled-bunch damping systems are discussed. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342582

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

The Spallation Neutron Source (SNS) Project is a collaborative effort to build the next generation neutron science facility at Oak Ridge, TN. The facility will deliver a 2 MW proton beam to a liquid mercury target. Neutrons from this target will be moderated and sent to several state-of-the-art instruments. Six national laboratories are involved in SNS construction. Berkeley (LBNL) will build the front end that produces a 2.5 MeV, 52 mA H-beam. Los Alamos (LANL) is responsible for the 1 GeV linac with a superconducting section provided by Thomas Jefferson (JLab). Brookhaven (BNL) is building the transfer lines and accumulator ring. Oak Ridge (ORNL) and Argonne (ANL) have responsibility for the target and instruments. All activities are coordinated by the SNS project office at Oak Ridge. The high beam power, a desired availability of 95&percent;, and an aggressive commissioning schedule lead to some interesting challenges in beam diagnostics. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342583

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Each major step towards higher energy particle accelerators relies on new technology. Linear colliders require beams of unprecedented brightness and stability. Instrumentation and control technology is the single most critical tool that enables linear colliders to extend our energy reach. In this paper we focus on the most challenging aspects of linear collider instrumentation systems. In the Next Linear Collider (NLC), high brightness multibunche+/e−beams, withL±=1012particles/pulse and&sgr;x,y∼50×5&hthinsp;&mgr;m,originate in damping rings and are subsequently accelerated to several hundred GeV in 2 X-band 11424 MHz linacs from which they emerge with typical&sgr;x,y∼7×1&hthinsp;&mgr;m.Following a high power collimation section thee+/e−beams are focused to&sgr;x,y∼300×5&hthinsp;nmat the interaction point. In this paper we will review the beam intensity, position and profile monitors (x, y, z), mechanical vibration sensing and stabilization systems, long baseline RF distribution systems and beam collimation hardware. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342584

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Consensus reached in the last few years that fourth generation light source will most likely be a X-ray or a UV coherent source based on single-pass high-gain free electron laser (FEL), such as Self Amplified Spontaneous Emission (SASE), or seeded high-gain harmonic-generation (HGHG) free electron lasers. High-gain(>107)required for single-pass FEL puts great constrain on the quality of electron beam, and demands detailed distribution information of electron beam in six-dimension. The typical accelerator system for single-pass FEL consists of a photocathode RF gun injection system, a linac and magnetic bunch compressors, and a long undulator. The major challenges in beam diagnostics for single-pass FEL are to characterize the pico-seconds high-brightness electron beam in six-dimension produced by photocathode RF gun injector, and improve the stability and reliability of the photocathode RF gun injection system. Characterization of short electron bunch (∼100 fs) produced by the compressors, and co-align the electron beam with FEL radiation inside long undulator are also critical for FEL performance. We will discuss many diagnostic techniques developed at the Brookhaven Accelerator Test Facility (ATF) for the photocathode RF gun injection system, present several techniques for femto-seconds bunch length measurement, especially RF kicker cavity. Tomography technique for both transverse and longitudinal phase space measurements is discussed. Concept of multiple alignment-laser stations is present for beam alignment in the long undulator. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1342585

出版商:AIP    

年代:1900

数据来源: AIP