BNL, Upton, Long Island, New York
The Faraday Cup Award is given for an outstanding contribution to the development of an innovative particle beam diagnostic instrument of proven workability. It is presented at the Beam Instrumentation Workshop (BIW), a biennial forum for in-depth discussions of techniques for measuring particle beams produced in accelerators. This session will present the latest Faraday Cup winner, and the Proceedings article associated with it will summarize the history of the award. After the award is presented, this year's honoree (a secret until the Workshop) will give a talk on the design and performance of the winning instrument. For more information on the Award, see http://www.faraday-cup.com.
ORNL, Oak Ridge, Tennessee
The Spallation Neutron Source accelerator systems are designed to deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H- injector, capable of producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current; a 1 GeV linear accelerator; an accumulator ring; and associated transport lines. The accelerator systems are equipped with a variety of beam diagnostics, which played important roles during beam commissioning. They are used for accelerator tuning and monitoring beam status during production runs. This talk will give an overview of our experience with the major SNS beam diagnostics systems.
SLAC, Menlo Park, California
The Linac Coherent Light Source (LCLS) X-ray FEL utilizing the last km of the SLAC linac has been operational since April 2009 and finished its first successful user run last December. The various diagnostics for electron beam properties including beam position monitors, wire scanners, beam profile monitors, and bunch length diagnostics are presented as well as diagnostics for the X-ray beam. The low emittance and ultra-short electron beam required for X-ray FEL operation has implications on the transverse and longitudinal diagnostics. The coherence effects of the beam profile monitors and the challenges of measuring fs-long bunches are discussed.
CERN, Geneva
The diamond beam monitor is a solid-state ionization chamber that stands out due to its fast and efficient charge collection and its high radiation tolerance. The diamond technology gives a charge collection time of less than 1 ns and lifetime studies made at CERN with 24 GeV protons showed a decrease in performance of only 50% at 10 MGy, which make this device particularly well adapted to applications in particle accelerators. A poly-crystalline CVD diamond beam monitor has been evaluated as a beam halo loss monitor for the CERN LHC accelerator. Despite the read-out being made through 250 m of cable, the tests showed a good signal-to-noise ratio of 6.8, an excellent double-pulse resolution of less than 5 ns and a high dynamic range basically unlimited except by the electronics. A single-crystalline CVD diamond beam monitor was built and tested in cooperation with Bergoz Instrumentation for ISOLDE at CERN for the HIE-REX upgrade. This device was used to measure the beam intensity for particle counting and for measuring the beam energy spectrum. An energy resolution of 0.6% and a time resolution of 39 ps were measured for a carbon ion energy of 22.8 MeV.
National Instruments, Austin
Since 1976, National Instruments (NI) has taken off-the-shelf semiconductor and computing technology and applied it to measurement, diagnostics and instrumentation needs. NI leverages the rapid technological advancement of the semiconductor and computer industry, while retaining the flexibility and ensuring interoperability between HW & SW. This technical session will focus on the various models of computation, multicore technology applied to measurement and diagnostic needs, communication protocols, timing and synchronization, and FPGA designed-in to meet custom needs. Additionally we will see examples of Graphical System Design being applied at CERN, Max Planck, LANL, ESO and how COTS HW & SW technologies can be used to solve instrumentation needs.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
The gas ionisation beam profile monitor is a well established piece of diagnostic hardware. The use of active devices such as micro-channel plates (MCP’s) and channeltrons within such a diagnostic can present problems with gain differences between channels. At the Rutherford Appleton laboratory we have produced a beam profile monitor that uses an array of 40 individually powered channeltrons; these devices were chosen over the MCP for their robustness and longer lifetimes. These channeltron devices (like MCP’s across their surface) can suffer from large variations in gain at the desired operating voltage. We have successfully shown that an additional in-built calibration system using a single, motorised , channeltron can overcome these issues. We report on the work to build the calibration system, and the 40 channeltron array. The PXI (National Instruments) system used to control the motor drive and provide the all data acquisition is also covered. Also we report the new high voltage drift field to reduce space charge effects on the beam profile. Ongoing work on understanding how the drift field as well the beam field affects the measured profile is also discussed.
NSTec, Los Alamos, New Mexico
LANL, Los Alamos, New Mexico
An optical diagnostic instrument developed for the acquisition of high-speed time-resolved images has been fielded at the Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility at Los Alamos National Laboratory. The instrument was developed for the creation of time histories of electron-beam cross-section through the collection of Cerenkov light. This is accomplished through four optical lines of sight that optically collapse an image, an optical fiber relay, recording instruments, and a tomographic reconstruction algorithm. The instrument may be operated, adjusted, and calibrated remotely due to potential adverse environmental conditions. The instrument was operated over the course of various activities during and after DARHT commissioning, and tomographic reconstructions reported verifiable beam characteristics. Results from the collected data and reconstructions and analysis of the data are discussed.
GSI, Darmstadt
Technical University Darmstadt, Darmstadt
TU Darmstadt, Darmstadt
Scintillating screens are widely used for transverse beam profile monitoring and pepper-pot emittance measuring instruments at accelerator facilities. For high current beam operations at the GSI heavy ion UNILAC, several inorganic scintillators were investigated under different ion beam conditions in the energy range from 4.8 to 11.4 MeV/u and currents up to some mA. The imaging properties of various scintillating screens were studied with respect to light yield and imaged beam width, i.e. important parameters for precise beam profile measurements. The measured light yield and beam width show a strong dependence on the scintillating material and change significantly with screen temperature. The spectral response of the materials was mapped for different temperature levels, using a spectrometer in the visible and near UV range. The results clearly demonstrate that the scintillating properties of the materials, and their temperature, are critical issues for high current operations and have to be taken into account for correct beam profile reading.
GSI, Darmstadt
LBNL, Berkeley, California
TU Darmstadt, Darmstadt
As conventional intercepting diagnostics will not withstand high intensity ion beams, Beam Induced Fluorescence (BIF) profile monitors constitute a preeminent alternative for non-intercepting profile measurements. This diagnostic technique makes use of optical emission of beam-excited gases. Recently BIF became an important diagnostic technique for beam profile measurement with applicability in beam tuning over a wide range of beams and accelerator conditions. Beam induced fluorescence spectra in the range of 300 - 800 nm were recorded with an imaging spectrograph for 5 MeV/u proton, S(6+) and Ta(24+) beams in nitrogen, Xe, Kr, Ar, Ne and He at 10-3 mbar gas pressure. Optical transitions were identified and associated with corresponding beam profiles. Effective light yields, normalized to the differential energy loss, are presented for all gas-species investigated. Since residual gas ionization is the basic process for BIF-monitors as well as for Ionization Profile Monitors (IPM), BIF-results are compared to IPM measurement data.
ELETTRA, Basovizza
Several diagnostic instruments for the FERMI@Elettra FEL, among them the Bunch Arrival Monitor (BAM) and the Cavity Beam Position Monitor (C-BPM), require accurate readout, processing, and control electronics. All systems must be also integrated within the main machine control system. The back-end platform, based on the MicroTCA standard, provides a robust environment for accommodating such electronics, including reliable infrastructure features. Two types of Advanced Mezzanine Cards (AMC) had been developed in-house and manufactured for meeting the demanding performance requirements. The first is a fast (160 MSps) and high-resolution (16 bits) Analog to Digital and Digital to Analog (A|D|A) Convert Board, hosting 2 A-D and 2 D-A converters controlled by a large FPGA (Virtex-5). The FPGA is also responsible for service and host interface handling. The latter board is Analog to Digital Only (A|D|O) Converter, derived from the A|D|A, with an analog front side stage made of four A-D converters. The overall systems’ architectures, together with the specific AMCs’ functionalities, are described. Results on performance measurements are also presented.
DESY, Hamburg
To control the beam position at the entrance of the FLASH dump a position monitor is required outside of the vacuum. When a charged particle travels through a gas it will ionize the atoms. Therefore the signal from a capacitive button monitor is caused not only by the electric field of the beam but also by the ionized atoms which add high background to the usable signal. To avoid the ionization signal a magnetic coupled monitor is designed. The monitor consists of four longitudinal loops symmetrically arranged at the tube wall. An analytical expression of the signal for this monitor is derived and compared with simulation. Raw data are compared with the expectation.
ANL, Argonne
Accurate and stable x-ray beam position monitors (XBPMs) are key elements in a feedback system for obtaining desired x-ray beam stability. For the low-emittance mode of operation of the APS, the cross sections of the undulator x-ray beams are not upright ellipses, and the effective beam sizes in the horizontal and vertical planes depend on the undulator gaps. These beam characteristics introduce strong gap dependence in blade-type XBPMs designed for upright elliptical beams. A center-of-mass detector XBPM will significantly reduce the gap dependence of the BPM readings. We report the development status of a high-power center-of-mass XBPM at the APS. We note that users often discard more than 50% of the undulator beam power outside of the monochromatic beam. These photons can be intercepted by the limiting aperture of the beamline, and then the x-ray fluorescence footprint can be imaged onto a detector. The position of the x-ray beam can be read out using position-sensitive silicon photodiodes. Thermal analyses show that the XBPM can be used for the measurement of beam with a total power up to 20 kW for the 7-GeV / 200-mA operation of a 5-m undulator in the APS.
ANL, Argonne
LBNL, Berkeley, California
Time-correlated single-photon counting (TCSPC) techniques have been used for bunch purity measurement since the Advanced Photon Source started operations. Over the past three years, improvements made in the monitor have increased the signal-to-noise ratio and dynamic range to above 10 billion. Recently, improvements of the timing resolution of TCSPC to < 50 ps FWHM allowed us to measure the longitudinal profile of individual bunches in the APS storage ring. The profile monitor uses a visible-light single-photon avalanche photodiode (SPAD) and a PicoHarp 300 TCSPC unit. Due to its robustness, the system operates continuously and measures the average longitudinal profile of the stored beam, updating the process variables for bunch phases and bunch lengths in intervals less than 30 seconds. In a third application, using a TCSPC x-ray detector with an x-ray wire scanner in the monochromatic beam of the diagnostics undulator, measurements of transverse profiles of individual bunches can be completed in less than 30 minutes. Since the beam sizes and phases are dependent on the bunch charge, these online tools will provide users with valuable information performing timing experiments.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
Capacitive pick-ups for closed-orbit measurements are presently under development for an Ultra-low energy Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR). Low-intensity, low-energy antiprotons impose challenging demands on the sensitivity of the monitoring system. The non-destructive beam position monitors (BPMs) should be able to measure 107 particles and give sufficient information on the beam trajectory. This contribution presents the status of the BPM project development. Main goals of the investigation include optimization of the mechanical design and preparation of a narrowband signal processing system.
NewPath, Salt Lake City, Utah
Others have shown that the voltages induced on one uniformly-wound toroidal coil and two sinusoidally-wound toroidal coils may be used to determine the current in a single filament and its coordinates. We have extended this technique to show that the voltages measured on a group of sinusoidally-wound toroidal coils may be used to approximate the distribution of current within their common aperture. This is possible because each measured voltage is proportional to the product of unique functions of the radial and azimuthal coordinates of each increment of the current [1,2]. We have developed matrix methods to determine the transverse distribution of the current and determined the sensitivity of these calculations to measurement errors. Shielded sinusoidally-wound coils with a precision of 0.02 cm have been prepared using rapid prototyping, and methods have been defined to prepare the next generation of these coils, which will have a precision of 0.001 cm, by using an engraving tool with the 4th axis of a vertical milling machine.
IAP, Frankfurt am Main
In beam diagnostics optical techniques had become increasingly important as they provide information with the advantage to have only minimal effect on the beam. The planned Frankfurt Neutron Source will consist of a proton driver LINAC providing beam energies up to 2.0 MeV. The rotatable diagnosis tank hybrid ion beam tomography tank HIBTT will be placed at the end of the low energy beam transport section (LEBT) to provide beam tomography based on the visible radiation of the ion beam in front of the RFQ. The beam energy in this section will be 120keV and the current 200 mA. Additional to the CCD camera that takes optical data for the tomography, other non-interceptive devices could be used to gain additional information. The question behind this hybrid approach on non invasive beam diagnostics is: which and how much information can be extracted from an ion beam without disturbing or destroying it. The actual contribution deals with the information of profile width in beam profile measurements. The presentation introduces a definition and an information sensitive method for profile width determination and verifies them using experimental and numerical data.
CERN, Geneva
The BBQ tune (Q) and chromaticity (Q') diagnostic systems played a crucial role during LHC commissioning, both in establishing circulating beam and for the first ramps. Early on, they allowed identification of issues such as the residual tune stability, beam spectrum interferences and beam-beam effects – all of which may impact beam life times and are therefore being addressed in view of nominal LHC operation. This contribution discusses the initial beam stability in relation to the achieved instrumentation sensitivity, corresponding tune frequency and chromaticity resolution.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The ALBA Booster is a synchrotron designed to accelerate electron beam from 100 MeV to 3 GeV in a 3 Hz cycle. The maximum pulse coming from the ALBA Linac provides 4 mA in the Booster. In order to check all the Booster sub-systems, a Booster pre-commissioning took place during two weeks between December 2009 and January 2010. This paper presents the Diagnostics elements installed in the ALBA Booster and our experience during the Booster pre-commissioning.
Fermilab, Batavia
The Fermi National Accelerator Laboratory (FNAL) High Intensity Neutrino Sources (HINS) is a research project to address accelerator physics and technology questions for a new concept, low-energy, high-intensity long pulse H- superconducting linac. HINS will consist of a 50 keV ion source, a 2.5 MeV Radiofrequency Quadrupole (RFQ), and a 10 MeV room temperature spoke resonator acceleration section followed by superconducting spoke resonator acceleration sections. At this time a proton ion source and the RFQ module have operated with beam. This paper will present the results of first beam measurements through the HINS RFQ.
SLAC, Menlo Park, California
The Linac Coherent Light Source requires precision timing trigger signals for various accelerator diagnostics and controls at SLAC-NAL. A new timing system has been developed that meets these requirements. This system is based on COTS hardware with a mixture of custom-designed units. An added challenge has been the requirement that the LCLS Timing System must co-exist and “know” about the existing SLC Timing System. This paper describes the architecture, construction and performance of the LCLS timing event system.
ELETTRA, Basovizza
The bunch arrival monitor (BAM) for the IV generation synchrotron light source FERMI@Elettra is presented. It is based on an original idea developed at FLASH/DESY, specifically designed and built in-house for FERMI@Elettra. Each BAM station consists of a front-end module, located in the machine tunnel, and of a back-end unit located in the service area. It makes use of the pulsed optical phase reference along with the stabilized fiber link. The front end converts the bunch arrival times into amplitude variations of the optical phase reference pulses distributed over the link. The analogue signal is generated at the e-beam's passage in a broadband pick-up and is sent to the modulation input of an electro-optical modulator (EOM). The back end acquires, synchronously, the amplitude modulated pulses, using a broadband photodiode and a fast analog-to-digital converter. The digitized data is sent to the machine control system for further processing. The dedicated analog-to-digital, conversion processing and communication board, part of the monitor back end, is briefly described. The BAM measurements performed on FERMI@Elettra at 10 Hz are presented.
DESY, Hamburg
DESY Zeuthen, Zeuthen
Additional beam diagnostics has been installed in the dump line at FLASH in 2009. Its purpose is to prevent damage by long high current electron beam pulses, as happened in autumn 2008, when a vacuum leak occurred near the dump vacuum window. Beam position monitors (BPM), scintillator-based loss monitors and temperature sensors have been installed thus far in the dump area. Additional BPMs and loss monitors have meanwhile been installed. These include a magnetic BPM placed after the vacuum window. Magnetic loops are used in order to prevent the influence of the ions on the pick-up signals. Four ionization chambers, consisting of air-filled tubes, and 4 glass fibers have been installed parallel to the vacuum pipe, along the last 2 m of beam pipe. Beam halo monitors were installed next to the magnetic BPM. These consist of 4 diamond and 4 sapphire sensors operating as solid state ionization chambers. The halo monitors are sensitive to very small losses. These additional diagnostic monitors were commissioned in autumn 2009, and have contributed to the successful run of long pulses with 3-9 mA current and up to 800 microsecond length. Their performance will be summarized in this paper.
LBNL, Berkeley, California
Laboratory high energy density experiments using ion beam drivers rely upon the delivery of high-current, high-brightness ion beams with high peak intensity onto planar targets. Solid-state optical scintillators are typically used to measure the ion beam spatial profile but they display dose-dependent degradation and aging effects. These effects produce uncertainties and limit the accuracy of measuring peak beam intensities delivered to the target. For beam tuning and benchmarking the incident beam intensity, we have developed a cross-calibrating diagnostic suite that both places a lower limit on intensity and extends the upper limit of measurable peak intensity dynamic range. Absolute intensity calibration is obtained with a 3 um thick tungsten foil calorimeter. We present experimental evidence for peak intensity measures in excess of 200 kW/cm2 using a 300 kV, 25 mA, 5-20 usec K+ beam driver. Radiative models and thermal diffusion effects are discussed as they affect temporal and spatial resolution of beam intensity profiles.
BNL, Upton, Long Island, New York
The NSLS-II Injector System Diagnostics will provide instrumentation in the Linac, Booster, transfer lines and beam dumps for measuring key beam parameters. These instruments will be adequate in providing staged commissioning of NSLS-II injectors, as well as allowing sufficient beam diagnostics for tune-up and top up operations. This paper will summarize the progress and implementation status of the NSLS-II injector system diagnostics.
LAL, Orsay
The PHIL (PhotoInjector at LAL: http://phil.lal.in2p3.fr/ ) accelerator is the new LAL (Orsay, France) facility dedicated to test state-of-the-art RF and beam sources technologies used for future electron accelerators. The machine based on 3 GHz RF gun triggered with a 262 nm wavelength laser, delivers a low energy ( E<10 MeV) single pulse electron beam at 5 Hz, with a low charge (0.1 nC) for now. The machine is about 5 meters long, with one direct and one deviated beam line (created after a 60° dipole). This paper describes the current status (first beam in november 2009) and the development of the diagnostics sections of the machine. At present, the machine is equipped by a transverse beam profile monitor based on «YAG:Ce» screen (30 mm diameter and 300 micrometers thick), two BPMs (one "button type" and one "reentrant resonators" type) and two Faraday cups (at the end of each line). The paper will present some preliminary results of the dimension and position of the beam at specific point for different charges and phase, and will present the expected development of the diagnostics of the machine (measurement of mean and energy dispersion, 2D emittance, beam length).
NSRRC, Hsinchu
Taiwan Photon Source (TPS) is a 3 GeV synchrotron light source which being in construction at NSRRC. Designs of various diagnostics are undergoing and will deploy in future to satisfy stringent requirements of TPS for commissioning, operation, and top-off injection. Design of the diagnostics for beam intensity observation, trajectory and beam positions measurement, destructive profile measurement, synchrotron radiation monitors, beam loss monitors, orbit and bunch-by-bunch feedbacks, filling pattern, etc. are in final design phase. Details of current status and implementation of the planned beam instrumentation system for the TPS will summary in this report.
NSRRC, Hsinchu
Diagnostics of the 1.5 GeV Taiwan Light Source (TLS) has been continue upgraded since it operation started in 1993. BPM electronics and orbit feedback system have been upgrade in 2008. Commercial photon BPM electronics was tested recently. The bunch-by-bunch feedback have been deployed to improve beam stability. These upgrades are contributed to improve beam quality a lots. These efforts will be addressed also.
BNL, Upton, Long Island, New York
A synchrotron light diagnostic beamline has been designed at the NSLS-II storage ring, using the dipole radiations. A "cold-finger" configuration has been selected to block the central x-rays. Beam power on the first mirror is less than 1 W, so no water cooling was required for this in-vacuum mirrors. The beamline layout and major applications will be discussed in this paper. Two vacuum ports are reserved in the NSLS2 booster ring to monitor the transverse profile as well as bunch length measurement during ramping. There will be a synchrotron light port in the BTS transport line for observing the injecting beam behavior during top-up operation.
LBNL, Berkeley, California
A hardware system that acquires and stores a large buffer of bunch-by-bunch 16-bit data has been realized. A high resolution (up to 16-bit) analog-to-digital converter (ADC), or bank of ADCs, samples the analog signal at the bunch frequency. The digitized data is fed into a Field Programmable Gate Array (FPGA), which contains an interface to a bank of double data rate (DDR) SDRAM type memory. With appropriate data bus widths, the FPGA bursts the ADC data into the DDR SDRAM fast enough to keep up with the bunch-by-bunch ADC data continuously. The realized system demonstrates continuous data transfer at a rate of 1 GByte/sec, or 16-bit data at 500 MHz, into a 64MByte SDRAM. This paper discusses the implementation of this system and the future of this architecture for bunch-by-bunch diagnostics.
LANL, Los Alamos, New Mexico
In a nutshell, the role of a beam diagnostic measurement is to provide information needed to get a particle beam from Point A (injection point) to Point B (a target) in a useable condition, meaning with the right energy and size and with acceptable losses. Specifications and performance requirements of diagnostics are based on the physics of the particle beam to be measured, with typical customers of beam parameter measurements being the accelerator operators and accelerator physicists. This tutorial will be a physics-oriented discussion of the interplay between tuning evolutions and the beam diagnostics systems that support the machine tune. This will include the differences between developing a tune and maintaining a tune, among other things. Practical longitudinal and transverse tuning issues and techniques from a variety of proton and electron machines will also be discussed.
JLAB, Newport News, Virginia
The advent of the energy recovering linac (ERL) brings with it the promise of linac-quality beams generated with near storage ring efficiency. This potential will not, however, be fulfilled without overcoming a number of technical and operational challenges. We will review the basics of ERL dynamics and operation, and give examples of idiosyncratic ERL behavior and requirements posing particular challenges from the perspective of diagnostics and instrumentation. Beam performance parameters anticipated in next-generation ERLs will be discussed, and a “wish list” for the instrumentation of these machines presented.
LANL, Los Alamos, New Mexico
The heart of the LANSCE accelerator complex consists of Cockcroft-Walton-type injectors, a drift-tube linac and a side-coupled linac. These systems are approaching 40 years of age and a project to re-establish high-power capability and to extend the lifetime is underway. Many of the present beam diagnostic systems are difficult to maintain, and the original beam position monitors don’t provide any data at all. These deficiencies hamper beam tuning and trouble-shooting efforts. One thrust of the refurbishment project is to restore reliable operation of the diagnostic systems. I will describe the present diagnostic systems and their limitations, and will present requirements and solutions for the next-generation diagnostics systems.
DESY, Hamburg
The European XFEL is a 4th generation synchrotron radiation source, currently under construction in Hamburg. Based on different Free-Electron-Laser and spontaneous sources, driven by a 17.5 GeV superconducting accelerator, it will be able to provide several user stations with photons simultaneously. Due to the superconducting technology high average as well as peak brilliance can be produced. Flexible bunch pattern will allow for optimum tuning to the experiments demands. This paper will present the current planning of the electron beam diagnostics. An overview of the entire system will be given, as well as detailed insight into the main diagnostic systems, like BPM, charge and transmission diagnostics, beam size and beam loss monitor systems.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
DITANET is the largest-ever EU funded training network in beam diagnostics. The network members – universities, research centres and industry partners – are developing diagnostics methods for a wide range of existing or future particle accelerators, both for electron and for ion beams. This is achieved through a cohesive approach that allows for the exploitation of synergies, whilst promoting knowledge exchange between partners. In addition to its broad research program, the network organizes schools and topical workshops for the beam instrumentation community. This contribution gives an overview of the Network's research portfolio, summarizes the main research results from the first two years of DITANET and presents past and future training activities.
PSI, Villigen
The 9th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators (DIPAC 2009) was hosted by Paul Scherrer Institute (PSI) and took place at the Hotel Mercure Conference Center in Basel, Switzerland, May 25-27, 2009. A record number of 210 registered participants contributed to an exciting scientific program with ten invited talks, fourteen contributed orals and 115 poster contributions. In this talk, I will provide an overview of the various fields of beam instrumentation discussed during the workshop. A number of highlights from the scientific program have been selected, illustrating some of the outstanding achievements in accelerator diagnostics, presented at DIPAC 2009.