C. Ozkan Loch, R. Ischebeck, N. Samadi, A.M.M. Stampfli, J. Vila Comamala
PSI, Villigen PSI, Switzerland
This poster will give an overview of the diagnostics development for SLS 2.0. Details on the beam size monitors in the storage ring, the screen monitors for the booster to ring transfer line, and beam loss monitors for the linac and storage ring will be presented. Test results carried out at the SLS will also be presented. BPMs and feedback systems are not covered in this contribution.
A.B. Barboutis, R. Klein, M. Müller
PTB, Berlin, Germany
The electron storage ring MLS (Metrology Light Source) is used by the Physikalisch-Technische Bundesanstalt (PTB), the German metrology institute, as a primary source standard of calculable synchrotron radiation in the ultraviolet and vacuum ultraviolet spectral range. For this, all storage ring parameters have to be appropriately set and measured with high uncertainty. E.g., the electron beam current can be varied by more than 11 orders. This adjustment of the electron beam current, and thus the spectral radiant intensity of the synchrotron radiation, for the specific calibration task is conveniently performed fully automatic by a computer program.
L.T. Stant, M.G. Abbott, L. Bobb, G. Cook, L. Hudson, A.F.D. Morgan, E.P.J. Perez Juarez, A.J. Rose, A. Tipper
DLS, Oxfordshire, United Kingdom
The UK national synchrotron facility, Diamond Light Source, is preparing for a major upgrade to the accelerator complex. Improved beam stability requirements necessitate the fast orbit feedback system be driven from beam position monitors with lower noise and drift performance than the existing solution. Short-term beam motion must be less than 2 nm/sqrt(Hz) over a period of one second with a data rate of 100 kHz, and long-term peak-to-peak beam motion must be less than 1 µm. A new beam position monitor is under development which utilises the pilot-tone correction method to reduce front-end and cabling perturbations to the button signal; and a MicroTCA platform for digital signal processing to provide the required data streams. This paper discusses the challenges faced during the design of the new system and presents experimental results from testing on the existing machine.
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J.C. Dooling, M. Borland, A.M. Grannan, C.J. Graziani, Y. Lee, R.R. Lindberg, G. Navrotski
ANL, Lemont, Illinois, USA
N.M. Cook
RadiaSoft LLC, Boulder, Colorado, USA
D.W. Lee
UCSC, Santa Cruz, California, USA
Funding:Work supported by Hard X-ray Sciences LDRD Project 2021-0119 and by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The reduced emittance and concomitant increase in electron beam intensity in Fourth Generation Storage Ring (4GSR) light sources lead to the challenging machine protection problem of how to safely dispose of the circulating charge during unplanned whole-beam loss events. Two recent experiments conducted to study the effects of 4GSR whole-beam dumps showed that damage to candidate collimator materials can be severe. This is a paradigm shift for SR light source machine protection. Typically the biggest threat to the machine is from CW synchrotron radiation. The choice of collimator material is important. High-Z, high-density materials such as tungsten may appear effective for stopping the beam in static simulations; however, in reality, short radiation lengths will cause severe destructive hydrodynamic effects. In our experiments, significant damage was observed even in low-Z aluminum. Thus unplanned, whole-beam dumps cannot be stopped in a single collimator structure. In this tutorial, alternatives such as multiple collimators and fan-out abort kicker systems will be discussed. Collimator design strategy and foreseen diagnostics for their operation will also be presented.
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K. Tian, S. Condamoor, W.J. Corbett, N.L. Parry, J.A. Safranek, J.J. Sebek, F. Toufexis
SLAC, Menlo Park, California, USA
SPEAR3 is a third generation synchrotron radiation light source, which operates approximately 9 months each year with a very high reliability. The beam loss monitoring system in the storage ring has recently been upgrade to the modern Libera system from the original legacy hardware. During the initial stage of the new beam loss monitoring system deployment, it was proved to be useful for a new lattice commissioning at SPEAR3. In this paper, we will report the progress in the Libera system commissioning at SPEAR3 and present some first results.
L. Crescimbeni, D.M. Haider, A. Reiter, M. Schwickert, T. Sieber, T. Stöhlker
GSI, Darmstadt, Germany
H. De Gersem, N. Marsic, W.F.O. Müller
TEMF, TU Darmstadt, Darmstadt, Germany
M. Schmelz, R. Stolz, V. Zakosarenko
IPHT, Jena, Germany
F. Schmidl
FSU Jena, Jena, Germany
T. Stöhlker
IOQ, Jena, Germany
T. Stöhlker, V. Tympel
HIJ, Jena, Germany
V. Zakosarenko
Supracon AG, Jena, Germany
Funding:Work supported by the BMBF under contract No. 05P21SJRB1. The Cryogenic Current Comparator (CCC) at the heavy-ion storage ring CRYRING@ESR at GSI provides a calibrated non-destructive measurement of beam current with a resolution of 10 nA or better. With traditional diagnostics in storage rings or transfer lines a non-interceptive absolute intensity measurement of weak ion beams (< 1 µA) is already challenging for bunched beams and virtually impossible for coasting beams. Therefore, at these currents the CCC is the only diagnostics instrumentation that gives reliable values for the beam intensity independently of the measured ion species and without the need for tedious calibration procedures. Herein, after a brief review of the diagnostic setup, an overview of the operation of the CCC with different stored ion beams at CRYRING is presented. The current reading of the CCC is compared to the intensity signal of various standard instrumentations including a Parametric Current Transformer (PCT), an Ionization Profile Monitor (IPM) and the Beam Position Monitors (BPMs). It was shown that the CCC is a reliable instrument to monitor changes of the beam current in the range of nA.
J. Breunlin, G. Felcsuti
MAX IV Laboratory, Lund University, Lund, Sweden
The MAX IV Laboratory, inaugurated in 2016, hosts a 3 GeV ultra-low emittance storage ring, a 1.5 GeV storage ring and a linear accelerator driven Short Pulse Facility to deliver synchrotron radiation to scientific users. A Stability Task Force has been assigned to ensure the delivery of stable beams since early on in the design phase of the laboratory and is continuing its work in an ongoing and multi-disciplinary effort. Measurements of the electron beam stability resulting from the passive stabilization approach taken for the two storage rings will be presented, as well as figures of beam stability with the Fast Orbit Feedback system in operation. Each ID beamline in the 3 GeV storage ring is equipped with a pair photon beam position monitors that are currently used to complement the electron beam position monitors. In the light of the city development around the MAX IV campus, maintaining the good mechanical stability of the laboratory has to be seen as an ongoing effort. A number of studies are being performed to identify possible risks and to decide where measures need to be taken.
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M. Masaki, H. Dewa, T. Fujita, H. Maesaka, K. Soutome, T. Sugimoto, S. Takano, M.T. Takeuchi, T. Watanabe
JASRI, Hyogo, Japan
T. Fukui, H. Maesaka
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
K. Kubota
SES, Hyogo-pref., Japan
K. Soutome, T. Sugimoto, S. Takano, H. Tanaka, T. Watanabe
RIKEN SPring-8 Center, Hyogo, Japan
We developed a new correction algorithm for closed orbit distortion (COD) based on adaptive feedforward control (AFC). The AFC system effectively works for the suppression of the fast COD due to known error sources with repetitive patterns such as helicity-switching undulators. The scheme aims to counteract error sources by feedforward correctors at the position or in the vicinity of error sources so that a potential risk of unwanted local orbit bumps, which is known to exist for the global orbit feedback, can be eliminated in a reliable and accurate manner. This option is especially advantageous when an error source causes an angular distortion of photon beams such as a fast orbit distortion near undulators. Thus, the AFC provides a complementary capability to a so-called fast global orbit feedback (FOFB) for coming next-generation light sources where ultimate light source stability is essentially demanded. In this talk, introduction to the AFC, its theoretical aspect and advantages, the system overview, the experimental results for the effects of AFC will be presented. M. Masaki, et al., J. Synchrotron Rad. 28, 1758-1768 (2021).
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P.H. Baeta Neves Diniz Santos, B. Keil, G. Marinkovic
PSI, Villigen PSI, Switzerland
RF Systems-on-Chip (RFSoCs) are FPGAs with CPUs, multi-GSample/s ADCs and DACs and other components on the same chip. We have evaluated the use of RFSoCs for low-latency multibunch (bunch-by-bunch) feedback and filling pattern (single bunch charge) measurement systems for the Swiss Light Source (SLS) storage ring. First results obtained with an RFSoC evaluation board will be presented.
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F. Falkenstern, J. Kuszynski, G. Rehm
HZB, Berlin, Germany
The "Booster Fillpattern Monitor" is used to measure currents in each individual electron bunch in the booster of the BESSY II machine. The booster with its circumference of 96 meters has space for max.160 electron bunches. The distance between the electron bunches of 60cm (96m/160) is determined by the RF Master Clock ~ 499, 627MHz. In practice, fill patterns of a one to five equally spaced bunches are in use. The fill pattern monitor digitizes electrical pulses generated from a strip line using a broadband ADC. The sampling frequency is selected as an integer fraction of the bunching frequency, acquiring the full fill pattern over a number of turns. Experiments performed at BESSY II demonstrate the performance of the setup and will be discussed.
S.J. Martens
University of Saskatchewan, Saskatoon, Canada
T. Batten, D. Bertwistle, M.J. Boland
CLS, Saskatoon, Saskatchewan, Canada
A transverse bunch-by-bunch feedback system has been installed in the storage ring at the Canadian Light Source (CLS) to counteract beam instabilities. The 2.9 GeV electron storage ring is 171~m in circumference with 13 insertion devices currently installed, each contributing to the impedance of the ring and lowering the instability threshold. The new Transverse Feedback System (TFBS) provides improved bunch isolation, higher bandwidth amplification and diagnostics to study, understand and damp these instabilities. This paper will show and overview of the system setup, examples of operational performance and results of the diagnostic capabilities, including tune feedback, grow/damp measurements and excite/damp measurements.
S. Preston, L. Bobb, A.F.D. Morgan, T. Olsson
DLS, Oxfordshire, United Kingdom
In the Diamond storage ring, the vertical emittance is kept at 8 pm rad by an emittance feedback which modifies the strengths of skew quadrupoles. A new feedback using a stripline kicker to control the vertical emittance by exciting the beam resonantly at a synchrotron sideband is planned to avoid modification of the optics. This is crucial for the anticipated Diamond-II upgrade of the storage ring, which will have a much smaller equilibrium emittance than the existing machine. A larger coupling is therefore needed to keep the vertical emittance at the same level, potentially reducing the off-axis injection efficiency and lifetime. Measurements of the beam oscillation and emittance have been performed at the existing storage ring to characterise the effects of chromaticity and impedance on the optimal excitation frequency, where the emittance is increased significantly while the beam oscillation is kept low. The implications for simulating the emittance feedback for the Diamond-II storage ring are also discussed.
Á. Freitas, V. Hardion, M. Lindberg, R. Lindvall, R. Svärd, C. Takahashi
MAX IV Laboratory, Lund University, Lund, Sweden
MAX IV is a fourth generation synchrotron facility at Lund, Sweden. It is composed by a full energy linear accelerator and two storage rings with 1.5 GeV and 3 GeV, which requires hundreds of beam position monitors. In this context, Libera Single Pass E and Libera Brilliance+ are employed as BPM instruments. This paper will present an overview of the control system suite used in the facility, including the communication, data acquisition and storage pipelines, monitoring, configuration and software maintainability.
