STFC/RAL/ISIS, Chilton, Didcot, Oxon
Imperial College of Science and Technology, Department of Physics, London
Fundación Tekniker, Elbr (Guipuzkoa)
University of Warwick, Coventry
Bilbao, Faculty of Science and Technology, Bilbao
Fundación TEKNIKER, Eibar (Gipuzkoa)
STFC/RAL, Chilton, Didcot, Oxon
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
Elytt Energy, Madrid
High power proton accelerators (HPPAs) with beam powers in the several megawatt range have many applications including drivers for spallation neutron sources, neutrino factories, waste transmuters and tritium production facilities. The UK's commitment to the development of the next generation of HPPAs is demonstrated by a test stand being constructed in collaboration between RAL, Imperial College London, the University of Warwick and the Universidad del Pais Vasco, Bilbao. The aim of the RAL Front End Test Stand is to demonstrate that chopped low energy beams of high quality can be produced and is intended to allow generic experiments exploring a variety of operational conditions. This paper describes the current status of the RAL Front End Test Stand.
GSI, Darmstadt
IAP, Frankfurt am Main
For injection into the ion trap facility HITRAP, the GSI accelerator complex has the unique possibility to provide beams of highly stripped ions and even bare nuclei up to Uranium at an energy of 4 MeV/u. The HITRAP facility consists of linear 108 MHz-structures of IH- and RFQ-type to decelerate the beams further down to 6 keV/u for capturing in a large penning trap for cooling purpose. The installation is completed except of the RFQ-tank. During commissioning periods in 2007 64Ni28+ and 20Ne10+ beam was used to investigate the beam optics from the experimental storage ring extraction to the HITRAP double-drift-buncher system. In 2008 the IH-structure decelerator and the downstream matching section was examined with 197Au79+ beam. Comprehensive beam diagnostics were installed: Faraday cups, tubular and short capacitive pick ups, SEM grids, YAG scintillation screens, a single shot pepperpot emittance meter, and a diamond detector for bunch shape measurements. Results of the extensive measurements are presented.
INFN/LNL, Legnaro, Padova
Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova
The SPES project* at Laboratori Nazionali di Legnaro foresees the contruction of a RIB facility based on a fission target driven by a 40 MeV proton beam. After the 238U carbide target the 1+ charged ions will be selected by a high resolution mass spectometer, charge enhanced by a charge breeder and accelerated up to 10 MeV/A for 132Sn. The Legnaro superconducting accelerator complex, PIAVE injector and ALPI main accelerator, in its present configuration fits the requirements for SPES post acceleration. Nevertheless an upgrade of its performaces both in overall transmission and final energy is needed and a solution which minimizes the impact on the present structures will be presented.
*http://www.lnl.infn.it/~spes/
NSCL, East Lansing, Michigan
The Re-accelerator being developed at the Michigan State University is a major component of a novel system proposed at the NSCL to first stop the high energy RIBs by the in-flight particle fragmentation method in a helium filled gas system, then increase their charge state with an Electron Beam Ion Trap (EBIT) charge breeder, and finally re-accelerate them to about 3 MeV/u, in order to provide opportunities for an experimental program ranging from low-energy Coulomb excitation to transfer reaction studies of astrophysical reactions. The accelerator system consists of a Low Energy Beam Transport (LEBT) with an external multi-harmonic buncher, a radio frequency quadrupole (RFQ) followed by a superconducting linac and a High Energy Beam Transport (HEBT). The superconducting linac will use quarter-wave resonators with bopt of 0.047 and 0.085 for acceleration and superconducting solenoid magnets for transverse focusing. The paper will discuss the recent progress of R&D and beam dynamics studies for the MSU Re-accelerator.
LANL, Los Alamos, New Mexico
Funding: This work supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396
The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory is the world's most advanced weapons test facility. DARHT contains two linear accelerators for producing flash radiographs of hydrodynamic experiments. High-speed electronics and optical instrumentation are used for triggering the accelerators and collecting accelerator data. Efficient and effective diagnostics provide basic information needed to routinely tune the accelerators for peak radiographic performance, and to successfully monitor the accelerators performance. DARHT's server and network infrastructure is a key element in providing shot related data storage and retrieval for successfully executing radiographic experiments. This paper will outline the elaborate Data Acquisition, Archival, Analysis, and Instrument Control System (DAAAC), as well as the server and network infrastructure for both accelerators.
LA-UR-08-03265
JINR, Dubna, Moscow Region
The report presents the development of investigations on ILC siting in the Dubna region and ILC related activity at JINR. The report will describe the fields of activities ongoing to support the ILC at JINR. In addition, other linear accelerator activities at JINR will be summarized.
SLAC, Menlo Park, California
Funding: US DOE
This paper reports the design and test results on novel topology, high-efficiency, and low operating temperature, 1,320-watt power modules for high availability power supplies. The modules permit parallel operation for N+1 redundancy with hot swap capability. An embedded DSP provides intelligent start-up and shutdown, output regulation, general control and fault detection. PWM modules in the DSP drive the FET switches at 20 to 100 kHz. The DSP also ensures current sharing between modules, synchronized switching, and soft start up for hot swapping. The module voltage and current have dedicated ADCs (>200 kS/sec) to provide pulse-by-pulse output control. A Dual CAN bus interface provides for low cost redundant control paths. Over-rated module components provide high reliability and high efficiency at full load. Low on-resistance FETs replace conventional diodes in the buck regulator. Saturable inductors limit the FET reverse diode current during switching. The modules operate in a two-quadrant mode, allowing bipolar output from complimentary module groups. Controllable, low resistance FETs at the input and output provide fault isolation and allow module hot swapping.
DESY, Hamburg
The XFEL injector building has a length of 74.3 metres and is divided by 2.5 m long concrete shielding wall. The section upstream the shielding wall will have a length of 42.3 m and give place for the gun, accelerating module, 3rd harmonic section, laser heater and the beam diagnostics section. At its end the possibility for the beam dump is foreseen so that the tuning of the beam in the injector would become possible without any impact on the subsequent parts of the XFEL. Each of these components sets certain requirements on beam optics which may compete with each other. Downstream the shielding the beam will be vertically displaced by 2.75 m over the distance of 20 m by means of the so called dogleg - a combination of two four cell arcs (8 cell system). Since the vertical displacement takes place there it is important to optimize cells in such an order that the chromatic effects don't impact the beam quality noticeably. In this paper we describe the solution for the beam optics at the XFEL injector.
CEA, Pontfaverger-Moronvilliers
Funding: CEA-DAM, Polygone d'Experimentation de Moronvilliers 51 490 Pontfaverger Moronvilliers (France). olivier.pierret@cea.fr
AIRIX is a 2 kA, 19 MeV, 60 ns, single shot linear accelerator that produces X-rays from the interaction between relativistic electrons and a Tantalum solid target (Ta). Focal spot size, integrated and temporal dose are the main characteristics that we need for the successful development of flash radiography at hydro test facilities. MTFX is a 12 bit Charge-Coupled Device (CCD) intensified camera which is equipped with a scintillator. It can give focal spot size measurements in two directions using a two dimensional wedge. By another way Mucaddix is a CVD Diamond detector which is integrated nearby the AIRIX X-ray beam source. It gives integrated dose, time resolve dose, temporal characteristics of the X-ray flash and timing of the flash respect to the start of object implosion. These two measurement systems are described and the quantified results are reviewed here.
KIP, Heidelberg
MPI-K, Heidelberg
Without an adequate set of beam instrumentation, it would not be possible to operate any particle accelerator, let aside optimize its performance. In a joint effort between several major research centres, Universities, and partners from industry, DITANET aims for the development of beyond-state-of-the-art diagnostic techniques for future accelerator facilities and for training the next-generation of young scientists in this truly multi-disciplinary field. The wide research program covers the development of beam profile, current, and position measurements, as well as of particle detection techniques and related electronics. This contribution introduces this new Marie Curie Initial Training Network, presents the DITANET partner institutes, and gives an overview of the networks broad research and training program.
CERN, Geneva
MPQ, Garching, Munich
Linac 4 is a 160 MeV H- linac which will become the new injector for CERN's proton accelerator chain. The linac will consist of 4 different rf structures, namely RFQ, DTL, CCDTL and PIMS running at 352.2 MHz with 2 Hz repetition rate and 0.4 ms pulse length. A chopper line ensures clean injection into the PS Booster. The combination of high frequency and a high-current, low-emittance beam calls for a compact design where minimum space is left for diagnostics. On the other hand, diagnostics is needed for setting up and tuning of the machine during both commissioning and operation. A measurement strategy and the corresponding choice of the diagnostic devices and their specific use in Linac4 are discussed in this paper.
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL, Chilton, Didcot, Oxon
Funding: Work supported by EU/FP6/CARE (HIPPI) RII3-CT-2003-506395
Among present challenges for beam diagnostics and instrumentation are issues presented by high beam intensity, brightness, resolution and the need to avoid inserting mechanical parts into the beam. This very often means applying non-destructive methods, which avoid interaction between ions and mechanical parts and, furthermore, allow on-line measurements during normal beam operation. The preferred technique for H- beams is the photo-detachment process where (laser) light within the range of 400-1000 nm has a sufficient continuous cross section to neutralize negative ions. The actual diagnostics are then applied to either the neutrals produced or the electrons. The latter are typically used for beam profiles whereas neutrals are more suitable for emittances, and form the subject of the present paper. This provides an overview of the basic features of the diagnostic technique, followed by a more intensive discussion of some experimental and theoretical aspects with emphasis on computing the 4 dimensional emittance using a method called Maximum Entropy (MaxEnt).
JLAB, Newport News, Virginia
CASA, newport news
Fermilab, Batavia
Optical diffraction radiation (ODR) is a promising technique, which could be used for non interceptive beam size measurements at future light sources. An ODR diagnostic station was designed and installed on a CEBAF transfer beam line. The purpose of the setup is to evaluate experimentally the applicability range for an ODR based non interceptive beam size monitor and to collect data to benchmark numerical modeling of the ODR. An extensive set of measurements were made at the electron beam energy of 4.5 GeV. The ODR measurements were made for both pulsed and CW electron beam of up to 80 uA. The wavelength dependence and polarization components of the ODR were studied using a set of insertable bandpass filters and polarizers. The typical transverse beam size during the measurements was ~150 microns. Complete ODR data, wavelength and polarization, were recorded for different beam sizes and intensities. The beam size was also measured with an optical transition radiation (OTR) as well as wire scanner located next to the ODR station. In this contribution we describe the experimental setup and present first results of the measurements with the comparison to the numerical simulations.
ORNL, Oak Ridge, Tennessee
Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
Charged-particle beam diagnostic devices such as wire scanners, wire harps, and laser scanners all provide data sets describing the one-dimensional density distributions of the beam at a particular location; these data are commonly called profile data. We use these data for further computations, usually beam properties such as position and size, but to do so requires a certain level of accuracy in the data. Thus, we must make real world considerations as to its information content. Specifically, we consider noise in the data and the fact that it is sampled. The operation of a typical profile device is outlined in order to create a general model for the data sets. Using signal processing techniques we identify the minimal sampling requirements for maintaining information content. Using Bayesian analysis we identify the most probable Gaussian signal within the data (the mean and standard deviation of the Gaussian signal can then be used for computations). Time permitting we present techniques for direct computation of beam properties using noisy, sampled profile data.
Fermilab, Batavia
Northern Illinois University, DeKalb, Illinois
Euclid TechLabs, LLC, Solon, Ohio
ANL, Argonne
Funding: Work supported by US. Department of Energy, under Contract No. DE-FG02-06ER41435 with Northern Illinois University.
We present a diagnostics suite and analyze techniques for setting up the longitudinal beam dynamics in ILC electron injectors and bunch compressors. Techniques to measure first order moment and recover the first order longitudinal transfer map of the injector intricate bunching scheme are presented. Coherent transition radiation diagnotics needed to measure and monitor the bunch length downstream of the ~5 GeV bunch compressor are investigated using a vector diffraction model. We finally introduce a new diagnostics capable of measuring time-transverse correlation along a single bunch. Such a diagnostics should be valuable for controlling emittance dilution via transverse wakefield and for properly setting the crab cavities needed for maximizing luminosity for non-zero crossing angle at the interaction point.
Plansee Metall GmbH, Reutte
Nb-RRR sheet material is one of the key components of super conducting linear particle accelerator projects (e.g. XFEL, ILC). The high quality requirements led to sophisticated quality systems in the manufacturing line. A major aspect is the development of non-destructive inspection methods for the detection of surface defects, delaminations, and inclusions. Up to now the standard inspection technologies for quality assurance of Nb-RRR sheet material are based on electromagnetic techniques, e.g. SQUID and eddy current. For these methods the detection limit is in the range of 0.1 mm. Ultrasonic microscopy (USM) in the frequency range of 1 GHz is a well established and economic technique for non-destructive surface inspection. For volume inspection of sheet material ultrasonic frequencies of 50 to 100 MHz are applied. For Nb-RRR sheets with typical thickness of 2.8 mm a detection limit of 0.1 mm is expected. First results of USM on Nb-RRR sheet material are presented.
GANIL, Caen
IPN, Orsay
The construction of the new Spiral 2 facility has started in Caen (France) at the National Heavy Ions Accelerator Center (GANIL). The SPIRAL 2 project is based on a multi-beam Superconducting Linac Driver delivering 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u delivering different Radioactive Isotope Beams (RIB). The LINAC is composed of 2 cryomodule families. The low energy family (cryomodules A) is composed of 12 cryomodules housing a single cavity at beta=0.07. The "high" energy family (cryomodules B) is composed of 7 cryomodules housing 2 cavities at beta=0.12. In between cryomodules are located the focalisation quadrupoles and the diagnostic boxes. Strong beliefs forbid the use of interceptives diagnostics around superconducting cavities. We simulated the use of wires for diagnostics in the linac, sublimating 14 wires of tungsten, Niobium and carbon while operating the B cavity at full performances. The first results describe in this paper looks promising.
Diversified Technologies, Inc., Bedford, Massachusetts
Funding: U.S. Department of Energy SBIR Program
Diversified Technologies, Inc. (DTI) has developed high power, solid-state Marx Bank designs for a range of accelerator and collider designs. We estimate the Marx topology can deliver equivalent performance to conventional designs, while reducing acquisition costs by 25-50%. In this paper DTI will describe the application of Marx based technology to two different designs: a long-pulse ILC focused design (140 kV, 160 A, 1.5 ms), and a short-pulse design (500 kV, 265 A, 3 us). These designs span the known requirements for future accelerator modulators. For the ILC design, the primary challenge is minimizing the overall size and cost of the storage capacitors in the modulator. For the short-pulse design, the primary challenge is high speed operation, to limit the energy lost in the pulse rise-time while providing a very tight (± 3%) voltage flattop. Each design demands unique choices in components and controls, including the use of electrolytic capacitors in the ILC Marx design. This paper will review recent progress in the development and testing of both of these prototype Marx designs, being built under two separate DOE Phase II SBIR grants.
SLAC, Menlo Park, California
ORNL, Oak Ridge, Tennessee
Funding: Work supported by the U.S. Department of Energy under contract DE-AC05-00OR22725
The rf source High Voltage Converter Modulator systems installed on the Spallation Neutron Source have operated well in excess of 200,000 hours, during which time numerous failures have occurred. An improved IGBT switch plate is under development to help mitigate these failures. The new design incorporates three significant improvements. The IGBTs are upgraded to 4.5 kV, 1200 A, press-pack devices, which increase the voltage margin, facilitate better cooling, and eliminate explosive disassembly of the package in the event of device failure. The upgrade to an advanced IGBT gate drive circuit decreases switching losses and improves fault-condition response. A common-mode choke is incorporated into the H-bridge to decrease dI/dt during a shoot-through condition, to further improve the circuit response to this fault condition. The upgrade design and development status will be presented.
SLAC, Menlo Park, California
Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515
A Marx-topology klystron modulator is under development as an 'Alternative Conceptual Design' for the International Linear Collider project. It is envisioned as a smaller, lower cost, and higher reliability alternative to the present, bouncer-topology, 'Baseline Conceptual Design'. The application requires 120 kV (±0.5%), 140 A, 1.6 ms pulses at a rate of 5 Hz. The Marx constructs the high voltage pulse by combining, in series, a number of lower voltage cells. The Marx employs solid state elements; IGBTs and diodes, to control the charge, discharge and isolation of the cells. The developmental testing of a first generation prototype, P1, is nearing completion. Development of a second generation prototype, P2, is underway. Status updates for both prototypes will be presented.
DESY, Hamburg
CRE, Wuppertal
The LLRF system of the European XFEL must fulfill the requirements of various stakeholders: Photon beam users, accelerator operators, rf experts, controls system, beam diagnostics and many others. Besides stabilizing the accelerating fields the system must be easy to operate, to maintain, and to upgrade. Furthermore it must guarantee high availability and it must be well understood. The development, construction, commissioning and operation with an international team requires excellent documentation of the requirements, designs and acceptance test. For the rf control system of the XFEL the new system modeling language SySML has been chosen to facilitate the system engineering and to document the system. SysML uses 9 diagram types to describe the structure and behavior of the system. The hierarchy of the diagrams allows individual task managers to develop detailed subsystem descriptions in a consistent framework. We present the description of functional and non-functional requirements, the system design and the test cases. An attempt of costing the software effort based on the use case point analysis is also presented.