| Paper |
Title |
Page |
| MOPKF006 |
Enhancements of Top-up Operation at the Swiss Light Source
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309 |
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- B. Kalantari, T. Korhonen, A. Lüdeke, C. Quitmann
PSI, Villigen
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Since the first experience on 2001, Top-Up is the standard mode of operation at the Swiss Light Source (SLS) for users. In order to fulfill the ongoing demands of machine experts and experiments we have had to add more functionality to the Top-Up mode thus make it more flexible. Some time-resolved experiments require a constant charge in a single isolated bucket in the gap of the normal filling of a bunch train of 80% of the circumference of the storage ring. Therefore the Hybrid application was developed that keeps the beam current distribution constant in this mode. We developed a maintenance mode too, to allow to work continuously on the Linac and booster - for example to optimize injection/extraction - without disturbing the Top-up for user operation. Even beam destructive experiments at the Linac during Top-Up or Hybrid operation are supported, where the Linac can be used synchronously at the times between successive refilling of the storage ring. The flexible control and timing systems at the SLS made these applications feasible. We describe the controls, operation and applications of each of the above functionalities in this paper.
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| WEPLT049 |
Timekeeping Mechanism at SLS/APS Control System
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1945 |
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- B. Kalantari, T. Korhonen
PSI, Villigen
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Time is one of the most important and critical parameters in a distributed control and measurement system. It is especially crucial when we need to interpret correlation of different archived process variables (PV) during the time. Advanced Light Source (APS) and Swiss Light Source (SLS) are using a very similar control system toolkit (EPICS) and the same mechanism for timekeeping. Many input/output controllers (IOC) around the accelerator complex (including beamlines), run under a real-time operating system, and carry out the controls and data acquisition. Each IOC is responsible of keeping its own local time and time-stamps the local PV?s but tightly synchronized with a central timing IOC. Dedicated timing hardware and network makes it possible to maintain synchronous timestamps with real-time clock. In this paper we describe the principle of this mechanism, its advantages, our experiences and further improvements.
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| THPLT025 |
Using Visible Synchrotron Radiation at the SLS Diagnostics Beamline
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2523 |
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- V. Schlott, M. Dach, Ch. David, B. Kalantari, M. Pedrozzi, A. Streun
PSI, Villigen
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A diagnostics beamline has been set-up at the BX05 bending magnet of the SLS storage ring. It is equipped with a standard bending magnet front end, including two photon beam position monitors (PBPM) for determination of photon beam angle and position as well as a pinhole array monitor for online monitoring of beam size. The visual part of the dipole radiation is transported to an optical lab, where the temporal profile of the storage ring bunches can be measured with a minimal time resolution of 2 ps using a dual sweep, synchrocan streak camera. Simultaneously, beam size and coupling can be measured at 1.8 keV radiation energy with a zome plate monitor overcoming diffraction limitations. This paper describes the beamline design and summarizes the first experimental results.
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| THPLT186 |
Bunch Pattern Control in Top-up Mode at the SLS
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2882 |
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- B. Kalantari, T. Korhonen, V. Schlott
PSI, Villigen
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One of the crucial issues in the advanced third generation light sources is the bunch pattern control in the storage ring, where various filling patterns are of interests for different experiments. The most important step is to keep a uniform charge distribution over all (electron) bunches during the top-up operation. Such a bunch pattern control has been implemented at the Swiss Light Source (SLS). It provides a filling pattern with bunch-to-bunch fluctuation of a few percent. Since a dependency of the medium term orbit stability on the actual filling pattern was observed in the past, the stability could significantly be improved. Three major ingredients have made the implementation possible: precise timing system, flexible control system and sophisticated diagnostics. The method is being used in the user operation recently and proved to be reliable. This paper describes the hardware and software involved in the mentioned technique.
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