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.
ORNL, Oak Ridge, Tennessee
Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
3D computer simulations are performed to study magnetic field qualities in the SNS ring extraction Lambertson septum magnet. This work is motivated by the existence of a significant skew quad term in the magnet that has been identified as the source of causing a beam profile distortion on the target. The skew quad term is computed with different methods in simulations and is compared to measurement data. The origin of the large skew quad term is thoroughly investigated. The remedy for minimizing the skew quad term by modifying the magnet is also proposed. Particle tracking has been performed to verify the beam profile evolution through the existing and modified septum. The magnetic interference to the septum performance from an adjacent quadrupole is also assessed. This paper reports our simulation techniques and major results.
PAL, Pohang, Kyungbuk
Funding: Supported by the MOEST of Korea and by POSCO
Pohang Accelerator Laboratory (PAL) is planning to upgrade the Pohang Light Source (PLS) which is a 3rd generation light source operating since 1995. The key features of the upgrade are, decrease of the beam emittance to 5.6 nm, increasing the beam energy to 3.0 GeV, additional shorter straight sections for more insertion devices. Because the PLSII should use practically same circumference preserving the shielding wall structure of the existing PLS, the lattice space is squeezed to the limit to secure the additional space for the insertion devices. This requirements forces heavy use of the combined function magnet. All dipoles are replaced to gradient magnet, and all sextupoles have horizontal corrector winding, vertical corrector winding, skew quadrupole windings. In this report, the design features and engineering efforts for the PLSII magnet systems are reported.
PAL, Pohang, Kyungbuk
Funding: * Work supported by Korean Ministry of Education Science and Technology
The magnets for a medical synchrotron were designed. The synchrotron is for cancer therapy with proton and carbon-iron beams. The magnets for the injection include a septum magnet and an electrostatic septum magnet. And the magnets for the extraction include a resonance sextupole magnet, an electrostatic septum magnet, a thin septum magnet, and a thick septum magnet. The design achieved good field uniformity and acceptable leakage field level. We used 3D code for the electromagnetic simulation and the optimization of magnetic structures. In this paper, the basic design process for the injection and extraction magnets will be presented.
CERN, Geneva
National Technical University of Athens, Zografou
IN2P3 IPNL, Villeurbanne
HU/AdSM, Higashi-Hiroshima
KEK, Ibaraki
LAL, Orsay
BNL, Upton, Long Island, New York
The Compton positron source of a future linear collider must obtain the target bunch population by accumulating a large number of positron packets, arriving either in a number of bursts from a “Compton ring”, with intermediate damping of the scattering electron beam, or quasi-continually from a “Compton energy recovery linac”. We present simulation results for the longitudinal stacking of Compton positrons in the ILC damping ring and the CLIC pre-damping ring, reporting parameter optimization, stacking efficiency, possible further improvements, and outstanding questions.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
The latest initiatives to design and build non-scaling FFAGs have encountered novel technical challenges; the required DC combined function magnets (normal and superconducting) and fast pulsed magnets for injection and extraction present new problems. The talk will report on progress in meeting these challenges for the non-scaling machines, EMMA and PAMELA and will provide details of their current design status. With the main EMMA ring magnets now being delivered and the injection and extraction magnets being assembled in-house, practical engineering features of these systems will be presented.
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.
BNL, Upton, Long Island, New York
BESSY GmbH, Berlin
The NSLS-II is a state of the art 3 GeV synchrotron light source that is being developed at BNL. The 9.3 meter long injection straight section of NSLS-II storage ring currently fits a conventional injection set-up that consists of four kickers producing a closed bump together with a DC septum and a pulsed septum. In this paper we analyze alternative options based on: a) injection via a pulsed sextupole and b) injection with a Lambertson septum. We discuss dynamics of the injected and stored beams and, consequently, magnet specifications and tolerances. In conclusion we summarize advantages and drawbacks of each injection scheme.
HZB, Berlin
FhG, Euskirchen
PTB, Berlin
The 0.6 GeV storage ring Metrology Light Source (MLS) is in operation since April 2008. Recently, Cherenkov glass fibers have been installed for a temporal and spatial detection of electron beam losses. Based on this information the loss mechanisms can be studied in detail and the performance of the machine can be optimized. First experiments with this diagnostic tool will be presented.
ANL, Argonne
Funding: This work was supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The envisioned next-generation ERL-based x-ray light sources demand costly CW superconducting linacs and high-brightness high-current photoinjectors that are beyond the state of the art. To overcome the fiscal challenge of a multi-GeV CW superconducting ERL and the physical challenge of high-brightness high-current CW photoinjectors, we explore a new scheme using multi-beam injection into a quasi-CW ERL. Multi-beam injection lowers the burden on individual rf injectors at subharmonics of the linac frequency. Lower injector frequency allows higher bunch charge, which permits lower duty factor of the linac with significant reduction in construction and operation costs. Preliminary studies foresee many benefits and no obvious physical showstoppers, despite potential technical challenges. Here we provide a simulation study of a preliminary design.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
Funding: ISIS
The Extracted Proton beam line for the ISIS second target station has two 10 Hz pulsed magnet systems and a DC Septum magnet system which extract the protons from the existing 50 Hz beam line. The pulsed Kicker 1 magnet system deflects the beam 12.1 mrad, pulsed Kicker 2 deflects the beam 95 mrad and the DC Septum magnet system deflects the beam 307 mrad. This paper describes the topology, installation, testing and successful operation of each of the power supplies.
CERN, Geneva
The Multi-Turn Extraction, a new type of extraction based on beam trapping inside stable islands in the horizontal phase space, has been commissioned during the 2008 run of the CERN Proton Synchrotron. Both single- and multi-bunch beams with a total intensity up to 1.4×1013 protons have been extracted with efficiencies up to 98%. Furthermore, injection tests in the CERN Super Proton Synchrotron were performed, with the beam then accelerated and extracted to produce neutrinos for the CERN Neutrino to Gran Sasso experiments. The results of the extensive measurement campaign are presented and discussed in details.
CERN, Geneva
The conceptual considerations of a fast injection system for protons and ions in the proposed PS2 accelerator are presented. Initial design parameters of the injection septum and kicker systems are derived, taking into account rise and fall times, apertures and machine optics. The requirements for an injection dump used for failures are described. Possible limitations and technical issues are outlined.
GSI, Darmstadt
The FAIR heavy ion synchrotrons SIS100/300 will provide heavy ion and proton beams with variable time structure. Fast extraction of compressed single bunches from SIS100, fast beam transfer between SIS100 and SIS300 and slow extraction from SIS100 and SIS300 will be provided. High average beam intensities and the generation of an uninterrupted linac-like beam are enabled by combining both heavy ion synchrotrons in different operation modes (fast acceleration and stretcher operation). In order to reduce beam loss at slow extraction of intense heavy ion beams and to minimize the beam load in subsequent accelerator structures, dedicated ion optical settings of the basic lattice functions and higher order corrections will be applied. However, the tight geometrical constraints in the rather short straight sections and the need to extract from both synchrotrons, fast and slow, at the same position and in parallel to the beam transport system, require operation parameters of the extraction devices close to the limits of technical feasibility. Higher order beam dynamics simulations and technical developments will be presented.
KEK, Ibaraki
The kicker of the damping ring for the International linear collider(ILC) requires fast rise/fall times(3 or 6ns) and high repetition rate(3 MHz). A multiple strip-line kicker system is developing to realize the specification*. We present results of the beam test at KEK-ATF by the strip-line kicker**. The multi-bunch beam, which has 5.6ns bunch spacing in the damping ring, is extracted with 308ns duration. Two units of the strip-line electrodes are used to extract the beam. The scheme of the beam extraction is same as the kicker of the ILC. A bump orbit and an auxiliary septum magnet are used with the kicker to clear the geometrical restriction.
*T. Naito et. al., Proc. of PAC07, pp2772-2274
**T. Naito et. al., Proc. of EPAC08, pp601-603
NSRRC, Hsinchu
National Tsing Hua University, Hsinchu
The Taiwan Photon Source (TPS) is a new 3 GeV synchrotron light source to be built at the National Synchrotron Radiation Research Center (NSRRC) in Taiwan. The design of TPS is aimed to provide a low-emittance and high-brilliance beam with operation in the top-up mode. In this paper we present the design of the TPS injection section and the transport line from booster to storage ring. The specifications and parameters of the septa, kickers, and ceramic chambers are also described.
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.
USTC/NSRL, Hefei, Anhui
Funding: supported by National Natural Science Foundation of China (10705027)
Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very poor beam life time. In order to run the ring stablely, Top-up injection will be necessary. Injection system will greatly affect the quality of beam. This article first give a physics design of injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam is given in the article.
Imperial College of Science and Technology, Department of Physics, London
BNL, Upton, Long Island, New York
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
STFC/RAL, Chilton, Didcot, Oxon
Non-scaling FFAG rings have been proposed as a solution for muon acceleration in the Neutrino Factory. In order to achieve small orbit excursion and small time of flight variation, lattices with a very compact cell structure and short straight sections are required. The resulting geometry dictates very difficult constraints on injection/extraction systems. The feasibility of injection/extraction is discussed and various implementations focusing on minimization of kicker/septum strength are presented.
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.
BNL, Upton, Long Island, New York
Funding: Work supported by U.S. DOE, Contract No.DE-AC02-98CH10886
Beam loss monitors have been used for more than a decade in the VUV ring at the NSLS. These have proved useful for optimizing injection and operation of the ring. Recently similar monitors have been installed in the Xray ring and are being used to better understand injection as well as operation of the ring. These units have been compared with the Bergoz Beam Loss Monitors, which have been mostly useful for operating beam losses. The experience with these units have led to an improved detector that is being considered by NSLS-II as a beam containment verification monitor, as well as diagnostic for optimization of injection efficiency.
BNL, Upton, Long Island, New York
Funding: Work Supported by the United States Department of Energy, Contract No. DE-AC02-98CH10886.
EMMA is an experiment to study beam dynamics in a linear non-scaling fixed-field alternating gradient accelerator (FFAG). It accelerates an electron beam from 10 to 20 MeV kinetic energy. To optimally perform these studies, one must be able to inject the beam at any energy within the machine's energy range. Furthermore, because we wish to study the behavior of large-emittance beams in such a machine, the injection systems must be able to inject the beam anywhere within a transverse phase space ellipse with a normalized acceptance of 3 mm, and the extraction systems must be able to extract from that same ellipse. I describe a computation of kicker and septum fields to achieve all of these requirements, and discuss how this interacts with the hardware constraints.
CERN, Geneva
The maximum intensity the CERN PS has to deliver is continuously increasing. In particular, during the next years, one of the most intense beam ever produced in the PS, with up to 3000·1010 proton per pulse, should be delivered on a regular basis for the CNGS physics program. It is now known that the existing radiation shielding of the PS in some places is too weak and constitutes a major limitation due to large beam losses in specific locations of the machine. This is the case for the injection region: losses appear on the injection septum when the beam is injected in the ring and during the first turn, due also to an optical mismatch between the injection line and the PS. This paper presents the experimental studies and the simulations which have been made to understand the loss pattern in the injection region. Possible solutions to reduce the beam losses will be described, including the computation of a new injection optics.
NSRRC, Hsinchu
After commissioning of new BPM system in the TLS, it would support functionality of turn by turn data which can be applied in independent component analysis (ICA). This data analysis method is a special case of blind source separation to separate multivariable signal and additive noise and shown to be a useful diagnostic tool in acceleration application. In this paper, we use the ICA method to analyze experimental BPM turn by turn data of the TLS storage ring, measure betatron tunes, and identify abnormal BPM signals. Other possible applications have been also further studied continuously.
NSRRC, Hsinchu
Since the diagnostic system built with the new BPM system upgrade in TLS, we can observe and analyze the orbit stability more clearly and systematically. The disturbances to cause orbit fluctuation mainly come from power supply ripple, ground vibration, ID effects and etc. Removing the disturbed source is a straight, effective but inactive solution. Orbit feedback system is therefore adopted to suppress the remaining noise. In this report, we will evaluate the orbit stability in TLS and present the efforts we have done to improve the orbit stability.
NSRRC, Hsinchu
Beam qualities include orbit stability and multi-bunch instability plays a crucial role for the operation of a synchrotron light source. To improve and to keep high beam quality, intensive correlation analysis is performed between data taken by electron BPMs and photon monitors. Efforts of this study will be summary in this report.
Naples University Federico II and INFN, Napoli
Istituto Nazionale di Fisica Nucleare, Milano
Naples University Federico II, Napoli
The use of BBAC (Back-to-Back Accelerating Cavity) tiles in proton Side Coupled Linacs can be extended down to energies of the order of 20 MeV, keeping more than suitable shunt impedances and energy gradients. However, the considerable energy absorption from the cavity noses may induce a remarkable increase in their temperature. This may cause both a strong duty-cycle-dependent detuning of the modules, and dangerous thermo-mechanical stress due to the non-uniform temperature distribution. An innovative shape of the BBAC tile is proposed, which allows to limit the temperature rise within a safe range, without introducing detrimental effects neither on the shunt impedance nor on the working frequency. A protocol for the design of such a cavity will be presented.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG to be hosted at Daresbury Laboratory. NS-FFAGs related to EMMA have an unprecedented potential for medical accelerators for carbon and proton hadron therapy. It also represents a possible active element for an ADSR (Accelerator Driven Sub-critical Reactor). This paper will summarize the design of the extraction / diagnostic transfer line of the NS-FFAG. In order to operate EMMA, the energy recovery linac ALICE shall be used as injector and the energy will range from 10 to 20 MeV. Because this would be the first non-scaling FFAG, it is important that as many of the bunch properties are studied as feasible, both at injection and at extraction. To do this, a complete diagnostic line was designed consisting of a tomography module together with several other diagnostic devices including the possibility of using a transverse deflecting cavity. Details of the diagnostics are also presented.