Paper | Title | Other Keywords | Page |
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MOPC05 | Beam Diagnostics of SuperKEKB Damping Ring | KEKB, beam-position, injection, beam-losses | 53 |
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The KEKB accelerator ceased operation in 2010, and is being upgraded to SuperKEKB. Adopting low emittance and high current beams, the design luminosity is set at 40 times larger than that of KEKB. We are constructing a damping ring (DR) in order to achieve a low-emittance positron beam for injection. Turn-by-turn beam position monitors (BPMs), a transverse feedback system, a synchrotron radiation monitor (SRM), a DCCT, loss monitors using ion chambers, a bunch current monitor and a tune meter will be installed for beam diagnostics at the DR. An overview of the instrumentation of the DR will be presented in this paper. | |||
MOPF19 | Injection Efficiency Monitoring System at the Australian Synchrotron | injection, booster, synchrotron, background | 248 |
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The Australian Synchrotron upgraded its user mode from decay mode to top-up mode in May 2012. To monitor the beam charge passing through the accelerator systems at key transfer points the transmission efficiency system has been upgraded. The original system could only measure the efficiency of the booster to storage ring injection. The new one calculates intermediate efficiencies between six points along the injection system, from the electron gun to the booster-to-storage ring transfer line. This is helpful to diagnose in real-time shot-to-shot the performance of the pulsed magnets, ramped magnets and ramped RF systems and their associated triggers. A software-based injection efficiency interlock has also been introduced, that can inhibit the gun when the machine settings are not optimal. This article details the architecture of the injection efficiency system and lists the improvements on the machine that have been carried out to obtain high quality data. | |||
TUPF21 | Response of Scintillating Screens to Fast and Slow Extracted Ion Beams | ion, target, GSI, radiation | 553 |
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Funding: Funded by German Ministry of Science (BMBF), contract number 05P12RDRBJ For the FAIR project, imaging properties of inorganic scintillators for high energetic heavy ion beams were studied. In order to investigate the characteristics of scintillation response and transverse beam profile, several experiments were conducted with slow (200 ms) and fast (1 μs) extracted 350 MeV/u Uranium beams from SIS18. The extracted particle number was varied between 105 and 109 particles per pulse for the irradiation of seven different scintillators: YAG:Ce-crystals with different qualities, pure and Cr-doped alumina as well as two phosphors P43 and P46. Additionally radiation resistance tests for all phosphor screens and the Cr-doped alumina screen were performed by irradiating with more than 700 pulses with 109 ions each. Linear response in scintillation light output as well as realistic statistical moments over the large range of ion intensities are presented for each material. Only minor changing in target response was observed after 45 minutes of permanent irradiation. |
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Poster TUPF21 [2.601 MB] | ||
TUPF27 | An Ultra Low-Noise AC Beam Transformer and Digital Signal Processing System for CERN’s ELENA Ring | CERN, diagnostics, pick-up, longitudinal | 571 |
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CERN’s Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator. Essential longitudinal diagnostics required for commissioning and operation include the intensity measurement for bunched and debunched beams and the measurement of Dp/p for debunched beams to assess the electron cooling performance. The beam phase information is also needed by the low-level RF system. The baseline system for providing the required beam parameters and signals is based upon two ultra-low-noise AC beam transformers and associated digital signal processing. The AC beam transformers cover different frequency regions and are an adaptation to the ELENA layout of those used in the AD. Two AC beam transformers will also be installed in the extraction lines to provide beam intensity and bunch shape measurements. The digital signal processing will be carried out with the leading-edge hardware family used for ELENA’s low-level RF system. The paper provides an overview of the beam transformer and head amplifier, as well as of the associated digital signal processing. | |||
WEBL2 | Applications of Stripline and Cavity Beam Position Monitors in Low-Latency, High-Precision, Intra-Train Feedback Systems | feedback, BPM, kicker, beam-position | 630 |
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Two, low-latency, sub-micron beam position monitoring (BPM) systems have been developed and tested with beam at the KEK Accelerator Test Facility (ATF2). One system (‘upstream’), based on stripline BPMs uses fast analogue front-end signal processing and has demonstrated a position resolution as low as 400nm for beam intensities of ~1 nC, with single-pass beam. The other (‘IP’) system, based on low-Q cavity BPMs and utilising custom signal processing electronics designed for low latency, provides a single pass resolution of approximately 100nm. The BPM position data are digitised by fast ADCs on a custom FPGA-based feedback controller and used in three modes: 1) the upstream BPM data are used to drive a pair of local kickers nominally orthogonal in phase in closed-loop feedback mode; 2) the upstream BPM data are used to drive a downstream kicker in the ATF2 final focus region in feedforward mode; 3) the IP cavity BPM data are used to drive a local downstream kicker in the ATF2 final focus region in closed-loop feedback mode. In each case the beam jitter is measured downstream of the final focus system with the IP cavity BPMs. The relative performance of these systems is compared. | |||
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Slides WEBL2 [1.934 MB] | ||
WEPC16 | The Design of BPM Electronic System for CSNS RCS | pick-up, BPM, injection, beam-position | 706 |
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A Beam Position Monitor (BPM) system has been designed for the Rapid Cycling Synchrotron (RCS) at the China Spallation Neutron Source (CSNS) to acquire beam position information. This article introduces the design and implementation of the BPM electronic system. The challenge of designing the BPM electronics is to acquire and process the signal with large dynamic range (5.8mV~32V) and changing width (80ns to 500ns). The analog circuit described in this paper, which is constructed of a single-stage operational amplifier and an analog switch, can cover the input signal with large dynamic range. Because of the minimum bunch length (80ns) and the requirement of position resolution, a 14 bit 250MHz ADC is adopted to digitize the signal. Besides, for BPM system, the demand of an accurate real-time position monitoring is mandatory. The algorithm developed in an FPGA is able to make Bunch-by-Bunch position calculation and Closed Orbit position calculation in real time. Also, some preliminary test results will be presented and discussed, which show that the resolution of Bunch-by-Bunch position is 0.8mm when the input signal is 5.8mV and the resolution of Closed Orbit position is 50um. | |||
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Poster WEPC16 [0.937 MB] | ||