SINAP, Shanghai
The Shanghai Synchrotron Radiation Facility (SSRF) is an intermediate energy, third generation light source. In December 2007, electron beam was stored and accumulated in the SSRF storage ring. Since then the accelerator commissioning and beam line installation have continued toward the scheduled user operation from May 2009 onwards. This paper presents an overview of the SSRF status and preparations for user operations.
Fermilab, Batavia
Funding: Work supported by the U.S. Department of Energy
The fabrication of the multi-element corrector magnets for the Fermilab Booster synchrotron has just been completed. These water-cooled packages include six different corrector types - normal and skews oriented dipole, quadrupole and sextupole elements. They will provide full orbit control, tune and chromaticity of the beam over the whole range of Booster energies, from 0.4 GeV to 8 GeV. During production, a set of quality assurance measurements were performed, including special thermal tests. This paper summarizes the results from these measurements as well as discussing some specific steps of the magnet fabrication process.
NSRRC, Hsinchu
The highly stable pulsed magnets are designed for injection and extraction the electron beams operation in Taiwan Photon Source. The injection to the booster at 0.15 GeV is performed with septum and kicker devices as well as the extraction from the booster at 3 GeV. There are 5 in-vacuum septum and kicker magnets used for booster injection and extraction processes. For the storage ring, an injection of the electron beam into the storage ring is performed with a septum magnet and four identical kicker magnets. All pulsed magnets are designed for injection into the 3-GeV storage ring. The kicker magnet is excited with a 4.8-μs half-sine current waveform. A prototype of kicker magnet with 0.6 m of length is made and tested for examining the field errors. The field performances of the kicker magnet are presented. All pulsed magnets are fed with special current waveform. Both pulsed magnets are considered with the goal to achieve reliable work.
NSRRC, Hsinchu
Abstract A 3-GeV electron-storage ring with tiny emittance has been designed for the Taiwan Photon Source (TPS) that will provide one of the world's brightest synchrotron x-ray sources. Sextupole magnets for the booster ring (BR) serve to correct the chromaticity of the beam particles. As an AC power supply is generally used in a booster ring to raise beam particles to a required energy, a power supply at 3 Hz AC is used to charge the sextupole magnet, which would induce eddy currents in the vacuum chamber resulting in a magnetic multipole field. As an aspect of the magnet design, decreasing the effect of an eddy current on the homogeneity of the magnetic field, the geometry and material of the chamber must be considered. We demonstrate the effects of an eddy current on the homogeneity of a magnetic field for a vacuum chamber of various types, and we discuss the magnetic circuit and the conductor design of the booster-ring sextupole. Analysis of the multipole field and eddy-current loss were included to assure the accuracy of the magnetic circuit design.
NSRRC, Hsinchu
The accelerator lattice magnets of the Taiwan Photon Source (TPS) with energy 3 GeV have been designed for the storage and booster ring. The magnetic computation codes of TOSCA and RADIA software packages were used to design the magnet circuits of the accelerator magnets. Meanwhile, the design of a magnet circuit must take into account both the requirements of accelerator physics and practical engineering constraints. The criterion of magnet design is to keep a rise of coil temperature within 10o C and a safety margin greater than 15 %. We apply pole edge shims and end magnet chamfers to enhance the field homogeneity and to decrease multipole components, respectively. The edge shim involves a smaller magnet dimension but maintains the same quality of the field. Use of an end magnet chamfer avoids field saturation. The mechanical engineering design of the storage ring magnets has been completed and the booster ring magnets have started to be designed. The 3D Solidworks package was used to draw and design the mechanical engineering. The prototype magnets of the storage ring have been contracted out to the local company in Taiwan and will be finished before the end of 2009.
USP/LAL, Sao Paulo
Funding: FAPESP, CNPq
The IFUSP Microtron transport line guides the 5 MeV electron beam from the booster to the main microtron, where it can be accelerated up to 38 MeV in steps of 0.9 MeV. A few meters after leaving the main microtron, the beam is guided to the experimental hall, which is located 2.7 m below the accelerator room. The beam leveling is made by two 90° bending magnets. In the experimental hall there is a switching magnet to drive the beam to two different experimental lines. Each of these lines has another 90° bending magnet. These magnets were designed, constructed and characterized. In this work we present the analysis of the field distribution of these 90° bending magnets. Comparison between field simulation and data from field mapping is presented. We also present a reproducibility analysis where the field distributions of two twin magnets are presented.
Sigmaphi, Vannes
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The paper presents the magnetic measurements of the 32 long dipoles and 8 short dipoles magnet manufactured by Sigmaphi for the ALBA synchrotron booster based in Spain. An extensive set of measurements based on search coils was made by Sigmaphi to characterize the magnetic field at different currents. This paper describes the magnetic measurements results. The measurements show the maximum field integral deviation between the magnets is within ± 3.10-3 as expected.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The vacuum system of CELLS is in the installation stage. The booster vacuum chambers have been assembled and baked out in a provisional laboratory ex-situ in the ALBA building and in less than two months (starting from February) all the booster vacuum system was installed inside the tunnel and under vacuum. All the storage ring vacuum chambers have been delivered and ready for installation, several chambers were tested at CELLS (tests include vacuum tests, dimensional check, magnetic permeability testsÂ…etc). All the tools needed for the assembly of the storage ring vacuum chambers have been delivered and tested at CELLS to validate the assembly procedure. Concerning the standard vacuum components; all the gauges and residual gas analyzers were delivered, all the ion pumps and controllers are at CELLS, the NEG pumps, leak detectors, roughing stations and the UHV valves were delivered too.
ESRF, Grenoble
This paper outlines the present status and configuration of the ESRF vacuum system and its performance over the last years. A short overview of the installed vacuum devices is given as well as an outlook of future developments towards the planned ESRF upgrade. The storage ring down times caused by vacuum accidents have been dramatically improved due to a systematical survey using advanced vacuum diagnostic tools. Their use and drawbacks will also be discussed in this paper.
BNL, Upton, Long Island, New York
Kyushu University, Hakozaki
IAP, Frankfurt am Main
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A new heavy ion preinjector, consisting of an Electron Beam Ion Source (EBIS), an RFQ, and IH Linac, is under construction at Brookhaven National Laboratory. This preinjector will provide ions of any species at an energy of 2 MeV/u, resulting in increased capabilities for the Relativistic Heavy Ion Collider, and the NASA Space Radiation Laboratory programs. Initial operation of the EBIS and RFQ will be reported on, along with the status of the construction and installation of the remainder of the preinjector.
LBNL, Berkeley, California
Funding: This work was supported by the Office of Science, U. S. Department of Energy, under Contract No. DE-AC02-05CH11231.
The Advanced Photoinjector Experiment (APEX) seeks to validate the design of a proposed high-brightness, normal conducting RF photoinjector gun and bunching cavity feeding a superconducting RF linac to produce nC-scale electron bunches with sub-micron normalized emittances at MHz-scale repetition rates. The beamline design seeks to optimize the slice-averaged 6D brightness of the beam prior to injection into a high gradient linac for further manipulation and delivery to an FEL undulator. Details of the proposed beamline layout and electron beam dynamics studies are presented.
Muons, Inc, Batavia
Fermilab, Batavia
Funding: Supported by STTR Grant DE-FG02-07ER86320 and FRA DOE contract number DE-AC02-07CH11359
Originally conceived as a solution for FFAG applications, a new compact RF cavity design that tunes rapidly over various frequency ranges can be used to upgrade existing machines. The design being developed uses orthogonally biased garnet cores for fast frequency tuning and liquid dielectric to adjust the frequency range and to control the core temperature. We describe measurements of candidate ferrite and dielectric materials. The first use of the new cavity concept will be for improvements to the 8 GeV Fermilab Booster synchrotron.
ANL, Argonne
Funding: U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
An investigation into development of a 200-kW CW solid state rf power system design to replace the existing klystron-based 352-MHz rf systems at the Advanced Photon Source has been started. The baseline 352-MHz solid state system design will consist of multiple 1-kW CW modules combined to produce a total output capability of 200-kW CW, sufficient to drive one single-cell storage ring cavity. A description of the 1-kW CW module building block of the solid state power sistem will be presented, along with results from hardware evaluation tests at the 1-kW CW level.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
ALICE (Accelerators and Lasers in Combined Experiments) incorporates two super-conducting radio frequency (SCRF) cryomodules each with two identical 9-cell cavities that are powered by 5 inductive output tubes (IOTs) from 3 different commercial suppliers. During the commissioning of the ALICE rf system numerous problems were encountered with the operation of the high voltage power supply and the auxiliary power supplies, which had to be resolved before the beam commissioning of the accelerator could commence. The issues encountered and measures taken to improve the operation of the rf system are described within this paper.
ELETTRA, Basovizza
The full energy injection is now the standard procedure for the Elettra synchrotron radiation light source. The four RF storage ring plants have been benefited by this procedure in terms of reliability and stability of operation. The injector booster RF plant is running well. A new High Order Mode (HOM) diagnostic board has been implemented using the radiofrequency (RF) cavity’s signal to improve the HOM’s detection. The analysis and the performances of the new Inductive Output Tube (IOT)based RF power transmitter are presented.
SESAME, Amman
Funding: SESAME (Synchrotron light-source for Experimental Science and Applications in the Middle-East) Allan, Jordan
The SESAME (Synchrotron light source for Experimental Science and Applications in the Middle-East) accelerator consists of a 22MeV Microtron, an 800MeV booster synchrotron and a 2.5GeV storage ring. Each accelerator has its own RF system. The Microtron RF frequency is 3GHz generated by a 2MW pulsed Magnetron while the booster and storage ring have a common 500MHz CW RF source. The Booster RF system consists of a DORIS cavity fed by a 2kW CW solid-state RF amplifier but the storage ring (SR) RF system has been designed based on four 500 MHz plants, each comprising a normal conducting (NC) single-cell cavity , powered with 140 kW (CW) by two combined 80kW IOTs to have maximum possible RF power in the cavity via a WR1800 waveguide line. In the initial phase, it has been decided to start with two ELETTRA type cavities and in final phase, four cavities will be accommodated in one straight section in the storage ring to have nominal energy and current in the machine. This paper presents status of installed Microtron RF system and modified booster RF system from BESSY I, as well as designed SESAME storage ring high power RF system and low level electronics.
BNL, Upton, Long Island, New York
The NSLS II is a state of the art 3 GeV synchrotron light source being developed at BNL. The injection system will consist of a 200 MeV linac and a 3GeVbooster synchrotron. The transport lines between the linac and booster (LtB) and the booster and storage ring (BtS) must satify a number of requirements. In addition to transporting the beam while mantaining the beam emittance, these lines must allow for commissioning, provide appropriate diagnostics, allow for the appropriate safety devices and and in the case of the BtS line, provide for a stable beam for top off injection. Appropriate diagnostics are also necessary in the linac and booster to complement the measurements in the transfer lines. In this paper we discuss the design of the transfer lines for the NSLSII along with the incorporated diagnostics and safety systems. Necessary diagnostics in the linac and booster are also discussed.
BNL, Upton, Long Island, New York
The NSLS II is a state of the art 3 GeV synchrotron light source being developed at BNL. The injection system will consist of a 200 MeV linac and a 3GeV booster synchrotron. The injection system must supply 7.3nC every minute to satisfy the top off requirements. A large booster acceptance is neccessary to have a high booster injection efficiency and alleviate the requirements on linac gun. We also anticipate transverse stacking of bunches in the booster to increase the amount of charge that can be delivered. We present studies of the anticipated booster stay clear including lattice errors and the ramifications for injection efficiency and transverse stacking.
BNL, Upton, Long Island, New York
BESSY GmbH, Berlin
NSLS-II injection system contains 13 pulsed magnets and their power supplies for injection in and extraction from the booster and injection in the storage ring. Requirement of having injection process transparent for the NSLS-II users translates into challenging specifications for the pulsed magnet design. To keep the beam jitter within 10% of radiation source size, relative kicker mismatch must be kept on 10-5 level and residual vertical field must be below few gauss in amplitude. In this paper we discuss specifications for the pulsed magnets, their preliminary design and parameters' tolerances.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
ALBA is the first 3rd generation synchrotron light source to be build in Spain. The project is in the process of installation, with the LINAC already commissioned, and the Booster and Storage Ring in the installation phase, and the building already completed. The Booster synchrotron is expected to be finish and commission by the end of summer 2009, and the storage ring commissioning should take place in spring 2010. Most of the major components are already delivered and tested in-house, among those the vacuum system, the magnets, the RF cavities, etc. In this paper, the status of the project and of the most relevant components is reviewed.
LBNL, Berkeley, California
Funding: This work was supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.
The upgrade of the Advanced Light Source to enable top-off operation has been ongoing for the last four years. Activities over the last year have centered around radiation safety aspects, culminating in a systematic proof that top-off operation is equally safe as decaying beam operation, followed by commissioning and full user operations. Top-off operation at the ALS provides a very large increase in time-averaged brightness to ALS users (by about a factor of 10) as well as improvements in beam stability. The presentation will provide an overview of the radiation safety rationale, commissioning results, as well as experience in user operations.
FEL/Duke University, Durham, North Carolina
BINP SB RAS, Novosibirsk
Funding: This work is supported by the US DoE grant #DE-FG02-01ER41175
A booster-injector synchrotron has been recently built and commissioned at Duke University to provide for the top-off injection into the storage ring in the energy range of 0.24 - 1.2 GeV. Booster injection kicker was designed with a pulse length of 18 out of 19 booster separatrixes, assuming a long train of electron bunches to be injected from the existing linac. Such scheme required a major linac upgrade from single bunch photo emission mode to a multibunch thermionic mode. A major disadvantage of the latter was much higher radiation levels in the facility. Since commissioning, the booster could only operate with one or two bunches limited by both long kicker pulse and single bunch injection from the linac. The consequent limitation of the injection rate restricted the capability of production of the Compton gamma rays in the loss mode, i.e. production of gammas with energy above 20-25 MeV, to about 5*108 photons per sec. Update of the linac for the repetition rate of up to 10 Hz, and modification of the injection kicker for 15 nS pulse length allowed us to developed an alternative multibunch injection scheme with a significant increase of the injection rate into storage ring.
FEL/Duke University, Durham, North Carolina
Funding: This work is supported by US Air Force Office of Scientific Research medical FEL grant FA9550-04-01-0086 and US Department of Energy grant DE-FG02-01ER41175.
The Duke Free-Electron Laser Laboratory (DFELL) operates several accelerators as a driver for storage ring based Free-Electron Lasers (FELs) and Compton gamma-ray source, the High Intensity Gamma-ray Source (HIGS). The HIGS is the most powerful Compton gamma-ray source in the world below 100 MeV. Since completing a major upgrade of the HIGS in 2007, the Duke storage ring FEL and HIGS gamma source have been operated extensively for user research programs. In 2008, the DFELL was merged with the Triangle Universities Nuclear Laboratory (TUNL) to become a major accelerator facility of the TUNL. The accelerator physics program at the DFELL covers a wide range of activities, from nonlinear dynamics research, to the study of beam instability with advanced feedback systems, to light source research and development, in particular, the FEL research and Compton light source development. In this paper, we will report our recent progress in accelerator physics research and light source development to meet new challenges of today's and future accelerators.
Fermilab, Batavia
Funding: Work supported by Fermi Research Alliance, LLC under contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Currently Main Injector delivers 330KW of beam power at 120 GeV by using multi-batch slip stacking. The beam power is expected to increase to 400KW after installing clearing gap kickers to eliminate the injection kicker gap loss. The plan to increase the beam power to 700KW for NOvA and the role of MI in Project-X (2.1MW operation) will be discussed.
Fermilab, Batavia
The multi-batch slip stacking has been used for operation since January, 2008 and effectively increased proton intensity to the NuMI target by 50% in a MI cycle. The MI accepts 11 pulses at injection energy from the Booster and sends two pulses to Anti-proton production and nine to the NuMI beam line. The total beam power on a cycle was increased to 340 KW on average. We have been doing beam studies in order to increase the beam power to 400 kW and to control the beam loss. We also discuss 12 batch slip stacking scheme which is going to be used for future Neutrino experiments.
Fermilab, Batavia
Muons, Inc, Batavia
Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The use of existing Fermilab facilities to provide beams for two muon experiments –- the Muon to Electron Conversion Experiment (Mu2e) and the Muon g-2 Experiment –- is under consideration. Plans are being pursued to be able to perform these experiments following the completion of the Tevatron Collider Run II with no impact to the on-going Main Injector neutrino program by using spare Booster cycles to provide 8.9 GeV/c protons on target. Utilizing the beam lines and storage rings used today for antiproton accumulation, beams can be prepared for these experiments with minimal disruption, reconfiguration or expansion of the Fermilab accelerator infrastructure. The proposed operational scenarios and required alterations to the complex are described.
CERN, Geneva
The CERN PS Booster (PSB) produces a variety of beam flavours for the LHC. While the nominal LHC physics beams require 6 Booster bunches with intensities up to 1.6·1012 protons per bunch, during the LHC commissioning single bunch beams with variable intensities as low as 5·109 protons have to be provided reproducibly. The final transverse and in many cases also the final longitudinal beam characteristics have to be achieved already in the PSB and can be very demanding in terms of beam brightness and stability. The optimized production schemes for the different LHC beam flavours in the PSB and the achieved machine performance are presented. Experience with the first beams sent to the LHC in September 2008 is discussed. An overview of the first measured results with a new production scheme of the nominal LHC beam using single instead of double-batch beam transfer from the PSB to the PS is also given.
Fermilab, Batavia
Fermilab is in the process of upgrading its Booster Correction Element System to include full field correction element magnets to correct position and chromaticity throughout the booster cycle. From a reliability standpoint, it is important to limit both the maximum temperature and the repetitive temperature cycling of the silicon junctions of the switching elements. We will describe how we measured these parameters and the results of our measurements.
Fermilab, Batavia
Fermilab is in the process of upgrading its Booster Correction Element System to include full field correction element magnets to correct position and chromaticity throughout the booster cycle. This upgrade requires power supplies with maximum outputs of ±180V/±65A, with current bandwidths of 5kHz and with slew rates of min to max current in 1ms. For seamless operation around zero current and voltage, we use continuous switching on both sides of the bridge. Although the straightforward way of coordinating the switching on both sides of the bridge can be accomplished with one triangle timing wave and one voltage reference, we have found that using two triangle waves yields a switching coordination that effectively doubles the frequency of the differential ripple on the load and allows for better and cheaper filtering of the output ripple.
LBNL, Berkeley, California
Funding: This work was supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source (ALS) is a third generation synchrotron light source that has been operating since 1993 at Berkeley Lab. Recently, the ALS was upgraded to achieve Top-Off Mode, which allows injection of 1.9GeV electron beam into the Storage Ring approximately every 30 seconds. Modifications required for Top-Off operation included replacing the booster dipole and quadrupole magnet power supplies to increase the peak booster beam energy from 1.5GeV to 1.9GeV. Each new power supply was originally controlled by an analog controller that performs the current feedback loop and, in concert with other modules in the control chassis, determines the output of the ramped power supply. The new digital power supply controller performs the current feedback loop digitally to provide greater output stability and resolution. In addition, it provides remote monitoring of feedback loop signals, interlocks, and status signals, as well as remote control of the power supply operation via Ethernet. This paper will present the ALS Digital Power Supply Controller module requirements and design.
NSRRC, Hsinchu
The Agilient 6682A power supply is used as a dipole magnet power supply of Booster to storage ring (BTS) transport line, its output current stability is less than 100 ppm although specification is 1000 ppm. The performance of Agilient 6682A is quite good for TLS operational requirement but not suitable for less than 10 ppm output current stability general requirement of power supplies of TPS. Circuitry modification of Agilient 6682A to reach less than 10 ppm output current stability is hard to implement; but utilize analog programming function of Agilient 6682A with adding an external current control loop the output current stability of Agilient 6682A could be improved to less than 10 ppm.
ELETTRA, Basovizza
The New Full-Energy Injector at Elettra, based on a 3 Hz, 100 MeV to 2.5 GeV booster has officially started its operations since March 2008*. The time schedule was fully respected notwithstanding the performance problems presented by some of the main magnet power supplies**. The refurbishing plan, formally started at the end of the commissioning phase and carried on together with the manufacturer, has brought positive results in approaching the required specifications. The paper will describe the progress of the refurbishing and the experience with the other magnet power supplies, including the positive performances of the in-house low-current (5A) bipolar power supplies, especially designed for the linac pre-injector***. A new version, fully digitally controlled, of these low-power power supplies will be adopted for some coils and magnets of the FERMI@Elettra project.
*M. Svandrlik, Status of the Elettra Booster Project, EPAC08
**R. Visintini, Magnet power converters for the Elettra Booster, EPAC08
***D. Molaro, A new bipolar PS for the Elettra booster, PCIM08
SLAC, Menlo Park, California
BNL, Upton, Long Island, New York
Funding: Work supported by the US Department of Energy, Office of Basic Energy Sciences.
In the past, SPEAR3 has had typically 50 to 70% injection efficiency. Much of the lost injected beam hit the small gap vacuum chambers at the insertion devices. We are now implementing injection with photon beamline shutters open, so these losses create Bremsstrahlung down the photon beamlines, increasing radiation levels on the photon experimental floor. In this paper, we describe work done to better control the booster to SPEAR (BTS) transport line beam so as to reduce losses during injection. We have used new BTS BPM electronics to control the transport line trajectory. The trajectory response on these BPMs has been used to correct the BTS optics. We use turn-by-turn BPM readings of the injected beam in SPEAR to optimize the BTS trajectory in all six transverse and longitudinal coordinates. We use turn-by-turn profile measurements of the injected beam to verify the BTS optics correction. The stainless steel windows have been removed from the BTS vacuum system to reduce the transverse dimensions of the injected beam.
FEL/Duke University, Durham, North Carolina
BINP SB RAS, Novosibirsk
Funding: Supported by US DoE grant #DE-FG02-01ER41175
The Duke FEL/HIGS (Free electron laser/High Intensity Gamma-ray source) facility has recently undergone through a series of major upgrade. As a part of this upgrade, a kicker system was designed to provide reliable injection from the booster into the storage ring at any energy chosen from the range of 240 MeV to 1.2 GeV. Relatively new and not sufficiently studied switching device has been selected as a basic component to build a set of nanosecond resolution high-voltage generators. So called Pseudo-Spark Switch (PSS), also known as a cold cathode thyratron, has the same or slightly better jitter, reasonable range of switched high voltages and significantly lower heater power as compared to the traditional “hot” thyratrons. Despite of the fact that it requires more complicated triggering system, this device still seems very attractive as a driver for short pulse kickers. Almost three years of operation of the Duke FEL facility has revealed number of advantages and challenges related to the thyratrons of this type. In this paper we depict design features of the kicker system, discuss some accomplished improvements and summarize our three year experience.
SESAME, Amman
The SESAME booster, with a circumference of 38 m, has several bending magnets, focussing quadrupoles and defocussing quadrupoles and also the injection and extraction septums and kickers. There wil be one ramping power converter which supplies a series of 12 dipole magnets. Also 12 focussing magnets family and 6 defocussing magnets family are supplied separately with two ramping power converters. Technical issues of all the ramping and pulsed power supplies needed for the SESAME booster are disussed in this paper.
NSRRC, Hsinchu
The quasi-constant current operation is achieved in the NSRRC by periodically injecting electrons from the booster to the storage ring. It means the booster RF system keeps running during operation period, even the injection period occupies only a small portion of the total operation time. To benefit both the energy saving and klystron life, an energy saving controller has been developed and integrated into the TLS booster RF system. The cathode current of the klystron is decreased during the top-injection period. The energy consumption is thus dramatically reduced. A continuous record since the beginning of 2009 shows this controller can save about 78 percent of energy consumption of the booster RF system during normal operation. An overview of the control architecture and its functionality is presented herein.
NSRRC, Hsinchu
The design work of the concentric booster for Taiwan Photon Source (TPS) has been well in progress. The circumference is 496.8 m. It consists of modified FODO cells with defocusing quadrupole and sextupole fields built in bending magnets, and combined function focusing quadrupoles with imbedded focusing sextupole. The emittance is about 10 nm-rad at 3 GeV. Several modifications on the structure were made to improve the beam dynamics behaviors. Good dynamic aperture and nonlinear behavior as well as good tunability are shown. The efficient closed orbit correction scheme is presented. The repetition rate is 3 Hz, and the eddy current effect is also discussed.
NSRRC, Hsinchu
The booster design of Taiwan Photon Source(TPS) has been significantly revised. Therefore, the transfer line from linac to booster(LTB) and the one from booster to storage ring(BTS) have been redesigned accordingly. The design of LTB transfer line has been simplified to reduce the number of magnets. The length of BTS transfer line has been greatly reduced. The design goal of transfer lines is to achieve high efficiency for beam injection. The status of current progress will be reported.
NSRRC, Hsinchu
A 3 GeV synchrotron light source is planned to be built at the existing site of NSRRC campus. The project is called the Taiwan Photon Source (TPS). It will provide x-ray photon beam with brilliance several orders higher than the one generated by the existing 1.5 GeV synchrotron. The design issues of accelerator lattice for the 3 GeV storage ring and booster injector will be presented. These issues cover the properties of linear and nonlinear beam dynamics, the optimization of dynamic aperture and momentum acceptance, collective beam instabilities and lifetime issues, the effects caused by various error sources and technical measures to suppress these error effects, etc.
ELETTRA, Basovizza
A full energy injector consisting of a 100 MeV linac and an up to 2.5 GeV booster is in operation since March 2008 replacing the previous 1 GeV linac injector to be used after refurbishing and upgrade for the new fourth generation light source (FEL) currently under construction at Sincrotrone Trieste. The measurements on the new injector, problems and solutions employed to increase its efficiency, reproducibility and reliability, aiming towards top-up operations in the near future, and its impact on the Elettra storage ring are presented and discussed.
SOLEIL, Gif-sur-Yvette
SESAME, Allan
SESAME is a 3rd generation synchrotron light source facility under construction in Allan, Jordan, 30 km North-West of Amman. SESAME consists of a 2.5 GeV storage ring, a 22.5 MeV Microtron and an 800 MeV Booster. The Microtron was installed at its final position and its subsystems have been successfully tested. The commissioning with beam of the Microtron will start in March 2009. The installation of the Booster is expected to take place in summer 2009. Most of the storage ring subsystems are ready for call for tender. The progress of SESAME project including beamlines status will be reported in this paper.
Muons, Inc, Batavia
Fermilab, Batavia
Intense muon beams have many potential applications. However, muons originate from a tertiary process that produces a diffuse swarm. To make useful beams, the swarm must be rapidly collected and cooled before the muons decay. A promising new concept for the collection and cooling of muon beams to increase their intensity and reduce their emittances is investigated: the use of a nearly isochronous helical cooling channel (HCC) to facilitate capture of the muons into a few RF bunches. Such a distribution could be cooled quickly and then coalesced efficiently into a single bunch to optimize the luminosity of a muon collider. An analytical description of the method is presented followed by simulation and optimization studies. Practical design constraints and integration into a collider, neutrino factory or intense beam scenario are discussed and plans for further studies are addressed.
BNL, Upton, Long Island, New York
The orbit bumps in NSLS booster are used to move the beam orbit within 2mm to the extraction septum aperture in a time scale of millisecond at extraction in order to reduce the required strength of the fast extraction kicker. Since before extraction, the beam stays on the distorted orbit for thousands of revolutions, there is a concern that this may cause charge losses. In order to find the optimal orbit bump setpoint which brings the maximum distortion at the extraction position and minimum distortions at other places, we developed the extraction model and performed an experiment to validate it. Afterwards, the model was applied to optimize the extraction process.
Fermilab, Batavia
Funding: Work supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
The Fermilab Main Injector is moving toward providing 400 kW of 120 GeV proton beams using slip stacking injection of eleven Booster batches. Loss of 5% of the beam at or near injection energy results in 1.5 kW of beam loss. A collimation system has been implemented to localize this loss with the design emphasis on beam not captured in the accelerating rf buckets. More than 90% of these losses are captured in the collimation region. We will report on the construction, commissioning and operation of this collimation system. Commissioning studies and loss measurement tools will be discussed. Residual radiation monitoring of the Main Injector machine components since 2004 will be used to demonstrate the effectiveness and limitations of these efforts.
NSRRC, Hsinchu
The air conditioning system for the 3.0 GeV Taiwan Photon Source (TPS) is currently under the design phase. This paper presents the latest design of the air conditioning system for the TPS. The capacity of the air handling unit (AHU), the dimension and layout of the wind duct were specified. Numerical analysis was applied to simulate the air flow and temperature distribution in one of 24 sections storage ring. A 1/12 experimental hall was also modelled. The air flow of this area was simulated.
RRCAT, Indore (M.P.)
Particle accelerator programs being pursued by the Indian labs cover a broad range, encompassing accelerators for nuclear physics research (NPR) (in the low and intermediate energy range), construction of synchrotron radiation sources (SRS) as well as participation in international accelerator projects, especially those related to high energy physics. Machines for NPR include 14MV Pelletrons, augmented by home built superconducting linac boosters to enhance the energy & mass range of the ion beams, and a superconducting cyclotron which is currently undergoing commissioning at Kolkata. Two SRS, namely, a 450 MeV ring Indus-1 and 2.5 GeV booster cum light source, Indus-2, have been indigenously constructed and set up at Indore. A program is also on to develop a high current proton accelerator that will eventually be used for R&D linked to ADS. Regarding our international collaborations, Indian labs have contributed to setting up of LHC at CERN, are associated with the CLIC Test Facility 3 & Linac-4 and the FAIR project at Hamburg besides working with Fermilab on ILC/Project-X R&D. The talk will give an overview of some of the recent developments related to these activities.
FEL/Duke University, Durham, North Carolina
TUNL, Durham, North Carolina
Funding: This work is supported by US Air Force Office of Scientific Research medical FEL grant FA9550-04-01-0086 and by US Department of Energy grant DE-FG02-01ER41175.
Since 2008, the upgraded High Intensity Gamma-ray Source (HIGS) at the Duke FEL Lab has provided users with gamma beams of unprecedented quality for scientific research. The recently completed accelerator upgrades include a HOM-damped RF cavity, a full-energy top-off booster injector, redesigned storage ring straight sections, and two new FELs. The HIGS facility is now capable of producing a high intensity gamma beam in a wide energy range (1 - 100 MeV) using commercial FEL mirrors. It has achieved an exceptionally high flux, up to ~1010 g/s total (< 20 MeV), making it the world's most powerful Compton gamma source. It produces almost 100% polarized gammas, either linear or circular. At the HIGS, the gamma energy can be changed rapidly within a factor of three in minutes. Operated by Triangle Universities Nuclear Laboratory since summer 2008, the HIGS is a dedicated Compton gamma source, capable of producing more than 2,000 h of gamma beam time per year with a five-day, two-shift schedule. Future development at the HIGS includes higher energy gamma beams toward the pion threshold and a rapid switch of circular polarization.
CERN, Geneva
The usual approach and treatment for the interaction of a particle beam with wake fields start from the assumption of ultrarelativistic beams. This is not the case, for example, for the Proton Synchrotron Booster (PSB) whose particles have a kinetic energy up to 1.4 GeV, with a relativistic gamma close to 2.5. There are some examples in literature which derive non ultrarelativistic formulas for the resistive wall impedance. In this paper we have extended the Broad-Band resonator model, allowing the impedance to have poles even in the half upper complex plane, in order to obtain a wake function different from zero for z greater than zero. The Haissinski equation has been numerically solved showing longitudinal bunch shape changes with the energy. In addition some longitudinal bunch profile measurements, taken for different energies and bunch intensities at the PSB, are shown.
CERN, Geneva
To understand one contribution to the intensity limitations of the CERN Proton Synchrotron Booster (PSB) in view of its operation with beams from Linac 4, the impedance of the machine has been characterized. Measurements of tune shift as a function of the intensity have been carried out in order to estimate the low frequency imaginary part of the impedance. Since the PSB is a low energy machine, these measurements have been done at two different energies,so as to enable us to disentangle the effect of the indirect space charge and resistive wall from the contribution of the machine impedance. An estimation of the possible resonant peaks in the impedance spectrum has been made by measuring a fast instability in Ring 4.
CERN, Geneva
The usual approach for the resistive pipe wall assumes the beam moves with the speed of light. For many low energy rings, such as the Proton Synchrotron Booster (PBS), possible performance limitations may arise from non relativistic resistive wall wake fields. In this regime not only the head of the bunch can interact with the tail but also the vice versa holds. In this paper we analyze numerical results showing the resistive wake field calculated from non relativistic impedance models. In addition we analyze the well known two particles model assuming that even the trailing particle can affect the leading one. We observe significant changes in the stability domain.
ANL, Argonne
Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) has three circular machines: a 7-GeV electron storage ring (SR), a booster synchrotron (booster) of beam energy 325 MeV to 7 GeV, and a particle accumulator ring (PAR). Their tune measurement systems are based on HP 4396 network and spectrum analyzers (NASA) and HP 89400 vector spectrum analyzers (VSA). The instruments are no longer supported by the vendor and will need replacement in the future. An upgrade of these systems with FPGA-based processors has been implemented. The new systems provided faster tune history and bunch-by-bunch tune reading in addition to the original systems. We present a brief description of the implementation and performance of the new systems.
Fermilab, Batavia
ANL, Argonne
Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The challenge of mitigating the strong enhancements of the optical transition radiation (OTR) signal observed after bunch compression in the Advanced Photon Source (APS) linac chicane and at the Linac Coherent Light Source (LCLS) has recently been addressed. We have demonstrated a technique to mitigate the intensity of the coherent OTR (COTR) relative to the OTR signals on the APS beams at 325 MeV. Since the previously reported spectral content of the COTR at LCLS after the first compression stage is similar, the concepts should also apply to LCLS. We utilized the stronger violet content at 400 nm of the OTR compared to the observed gain factors of the COTR in the blue to NIR regime. We also demonstrated the use of an LSO:Ce scintillator that emits violet light to support lower-charge imaging. Spectral-dependence measurements of the COTR were done initially at the 325-MeV station using a series of band pass filters inserted before the CCD camera, but recent tests with an Oriel spectrometer with ICCD readout have extended those studies and confirmed the concepts. These techniques are complementary to the proposed use of a laser heater to mitigate the microbunching itself at LCLS.
LBNL, Berkeley, California
CERN, Geneva
BNL, Upton, Long Island, New York
The Luminosity Monitor for the LHC has been built at LBL and is going to be installed in the LHC in early 2009. The device designed for the high luminosity regions (ATLAS and CMS) is a gas ionization chamber, that is designed with the ability to resolve bunch by bunch luminosity as well as survive extreme levels of radiation. During the experimental R&D phase of its design, the prototype of this detector has been tested extensively in RHIC as well as in the SPS. Result of these experiments are shown here, with comments on the implications for early operations of the LHC.
BNL, Upton, Long Island, New York
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The Booster to AGS (BtA) transfer line was designed to match both ions and protons into the AGS lattice. For proton beam operation the only constraint on the optics is to define a match to the AGS lattice. For ions operation there are constraints introduced by a stripping foil in the upstream part of the transfer line. For polarized proton operation there is the complication that the lattice to match into in the AGS is distorted by the presence of two partial snake magnets. In the 2008 polarized proton run it was observed that there was an optical injection mismatch. Beam experiments were conducted that showed disagreement with the model. In addition, these studies revealed some minor problems with the instrumentation in the line. A new model and more reliable measurements of the transfer line magnet currents have been implemented. Another series of experiments were conducted to test these modifications and to collect a more complete set of data to allow better understanding of the beam dynamics during the transfer and better understanding of the instrumentation. In this paper we will present the results of these experiments and comparison to the new model of the BtA.
BNL, Upton, Long Island, New York
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
As part of the efforts to increase polarization and luminosity in RHIC during polarized proton operations we have modified the injection optics and stripping foil geometry in the AGS Booster in order to reduce the emittance growth during H- injection. In this paper we describe the modifications, the injection process, and present results from beam experiments.
IHEP Beijing, Beijing
CERN, Geneva
A new design of the 6.6GeV Booster linac for CLIC which is based on the FODO lattice is presented in this note. Particle tracking studies using PLACET [1] are performed in order to estimate the single-bunch and multi-bunch emittance growth. First, the studies of optics are introduced. Then, the sing-bunch effects and multi-bunch effects are studied in the last two part of this note.
CERN, Geneva
At present, for most LHC type physics beams, six buckets of the PS operated with harmonic number h=7 are filled in two transfers, and each of the PS Booster rings provides only one bunch. The scheme presented aims at replacing the double batch transfer by a single batch transfer and is of interest (i) for the nominal 25 ns LHC beams once the Booster injection energy has been increased after completion of Linac4 and (ii) already now for 50 ns and 75 ns LHC beams less demanding for the Booster in terms of beam brightness. Two bunches with the correct spacing must be generated in the Booster rings by superposition of an h=2 RF system and a smaller h=1 component. Theoretical considerations and first experimental results will be presented.
ELETTRA, Basovizza
Elettra is the third generation light source in operation in Trieste since 1993,upgraded with a full energy booster injector last year. Top-up operation is on schedule in the near future but already the new timing system and gun are ready to operate in this mode. The paper describes all tasks and requirements needed to satisfy top-up injection include custom made hardware, interaction with controls and radiation protection system.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
Results of designing of the extended ALICE injector with the aim to include a special dedicated diagnostic line are presented. The purpose of the diagnostic line is to characterise the low energy beam, before it enters the booster, as much as possible. A key component of the ALICE is the high brightness injector. The ALICE injector consists of a DC photocathode gun generating ~ 80 pC electron bunches at 350 keV. These bunches are then matched into a booster cavity which accelerates them to an energy of 8.35 MeV. In order to do this, three solenoids and a single-cell buncher cavity are used, together with the off-crest of the first booster cavity where the beam is still far from being relativistic. The performance of the injector has been studied using the particle tracking code ASTRA.
Northern Illinois University, DeKalb, Illinois
ANL, Argonne
A transverse-to-longitudinal emittance exchange experiment is in preparation at the Argonne Wakefield Accelerator (AWA). The experiment aims at exchanging a low (< 5 mm-mrad) longitudinal emittance with a large (>15 mm-mrad) transverse horizontal emittance for a bunch charge of 100 pC. Achieving such emittance partitioning, though demonstrated via numerical simulations, is a challenging task and need to be experimentally verified. In this paper, we report emittance measurements of the beam in the transverse and longitudinal planes performed at 12 MeV. The measurements are compared with numerical simulations using Impact-T.
Illinois Institute of Technology, Chicago, Illinois
IIT, Chicago, Illinois
Fermilab, Batavia
Funding: This work supported by NSF grant No. 0237162, and DOE SCIentific Discovery through Advanced Computing: Accelerator science and simulation DE-PS02-07ER07-09
The FNAL Booster is a combined-function proton synchrotron with a bunch intensity of ~6·1010 protons; significantly greater than expected in the original design. The injection energy is 400 MeV (gamma factor 1.4), low enough for space charge forces to play a role in beam dynamics. The magnets are used directly as vacuum tanks, so the laminated pole surfaces contribute significantly to impedance. A study of the transverse coupling dependence on beam intensity is presented here. Experimental results are being analyzed using Synergia, a high-fidelity, parallel, fully 3D modeling code that includes both space charge and impedance dynamics. Previously, Synergia has always shown good agreement with experimental data. Our initial studies show that the direct space charge contribution to beam dynamics is too small to account for the increase in the coupling seen experimentally, corroborating analytic results. Parametric studies of the impedance needed to match the measured coupling are being done. Agreement between simulation and experiment should provide an independent measure of the Booster impedance, which has been analytically modeled and calculated elsewhere.
BNL, Upton, Long Island, New York
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An online modeling system is being developed for the RHIC injector complex, which consists of the Booster, the AGS and the transfer lines connecting the Booster to the AGS and the AGS to RHIC. Historically the injectors have been operated using static values from design specifications or offline model runs, but tighter beam optics constraints required by polarized proton running (e.g. accelerating with near-integer tunes) have necessitated a more dynamic system. An online model server for the AGS has been implemented using MAD-X as the model engine, with plans to extend the system to the Booster and the injector transfer lines and to add the option of calculating optics using the Polymorphic Tracking Code (PTC) as the model engine.
LBNL, Berkeley, California
Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The high-level software for the ALS injector control system is being rewritten synchronizing with the low-level hardware migration to the EPICS system*. New programs are all written in C# for the use on the new operator consoles that are Windows Vista PCs. We use SCA. NET for the channel access, WCF for IPC, and XML for configurations. GUI is currently in WinForm but moving to WPF. We will be reporting the result of the first release of the system from the aspect of the software development.
*The progress was reported at PCaPAC 2008 as http://users.cosylab.com/~mpelko/PCaPAC08/papers/mow02.pdf,and
http://users.cosylab.com/~mpelko/PCaPAC08/papers/tup018.pdf
LBNL, Berkeley, California
Funding: This work was supported by U.S. Department of Energy under Contract No. DE-AC03-76SF00098.
The Advance Light Source (ALS) is in the process of upgrading the high-level controls software. This welcome upgrade is driven by the need for a low-level controls hardware upgrade. The risk of a failure in some of the aging controls hardware is reaching a critical level. The dilemma is that replacing the low-level hardware will break some important control room applications. An effort has been started to replace all the high-level software in a way that is compatible with an incremental low-level hardware replacement. As will be presented in this paper, the plan involves combining three very different programming methods: C#, Matlab, and EPICS tools.
CERN, Geneva
The civil engineering works of the Linac4 linear accelerator at CERN started in October 2008 and regular machine operation is foreseen for 2013. Linac4 will accelerate H- ions to an energy of 160 MeV for injection into the PS Booster (PSB). It will thus replace the ageing Linac2, which presently injects at 50 MeV into the PSB, and it will also represents the first step in the injector upgrade for the LHC aiming at increasing its luminosity. This paper reports on the status of the design and construction of the main machine elements, which will be installed in the linac tunnel from the beginning of 2012 onwards, on the progress of the civil engineering and on the ongoing activities at the Linac4 test stand.
Istituto Nazionale di Fisica Nucleare, Milano
Universita' degli Studi di Milano & INFN, Segrate
Naples University Federico II and INFN, Napoli
CERN, Geneva
Bari University, Science Faculty, Bari
e2v, Chelmsford, Essex
INFN-Bari, Bari
ACLIP is a proton 3 GHz SCL linac designed as a booster for a 30 MeV commercial cyclotron . The final energy is 60 MeV well suitable for the therapy of ocular tumours or for further acceleration (up to 230 MeV) by a second linac in order to treat deep seated tumours. ACLIP has a 5 modules structure coupled together. The first one (able to accelerate proton from 30 to 35 MeV) has been completely assembled. High power tests are in progress at e2v in Chelmsford, UK, where the possibility of using magnetrons as the source of RF power is under investigation. Acceleration tests are foreseen for Spring 2009. In this paper we will review the main features of the linac and discuss the results of RF measurements, high power RF tests and possibly acceleration tests.
NSRRC, Hsinchu
Operation performance of the linear accelerator is crucial to satisfy stringent requirements for the top-up operation of the Taiwan Light Source. The performance of linear accelerator affects injector stability directly. Efforts to improve diagnostics and develop control applications for performance characterization are on going. Enhance operation performance of 50 MeV linac is also under way. Efforts for the improvement of the linac to provide better top-up injection performance will be summary in this report.