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At the University of Bonn, Germany, the storage ring ELSA extracts electrons with energies up to 3.2 GeV to hadron physics and novel detector testing experiments. We study the feasibility of replacing the current 26 MeV LINAC injector with a laser wakefield accelerator (LWA). For this, contemporary parameters from current LWA setups at other laboratories are assumed and matched to the acceptance of the booster synchrotron. Moreover, a conceptional draft of a potential LWA setup is created. This takes into consideration the influence of building conditions such as available floor space and building vibrations to estimate a setup and laser beam stability of a plasma generating high power laser system and beamline to the plasma cell. The methods and intermediate results of this study will be presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The Compton Polarimeter at the ELSA 3.2 GeV storage ring has been designed to measure the polarization degree of the stored electron beam by analyzing the profile of the back-scattered gamma-beam with a silicon microstrip detector. Utilizing a scattering asymmetry from interaction with circularly polarized laser light, the electron beam polarization is determined from the vertical shift of the gamma-beam’s center of gravity in respect to the handedness of the laser light. The installation of a new laser source and silicon strip detector has improved the polarimeter’s performance significantly. Additionally, the profile analysis could be enhanced by using a Pearson type peak function fit. The analyzing power was determined through the observation of the Sokolov-Ternov effect and a statistical measurement accuracy of 2 % could be obtained within 5 minutes of measurement time. The polarimeter resolves the expected spin dynamical effects occurring in the storage ring and has shown to be a robust and reliable measurement system for operation with the GaAs source for polarized electrons., Proceedings of the 11th International Beam Instrumentation Conference, IBIC2022, Kraków, Poland

The 3.2 GeV electron accelerator ELSA in Bonn consists of three acceleration stages each interconnected by tunable transfer beamlines. The steering of the electron beam through the transfer line from linear accelerator to the Booster Synchrotron is currently adjusted by hand, which limits a systematic improvement of the transfer efficiency. An automated optimization using the ‘‘simulated annealing’’ technique has been developed and integrated into the control system to improve the situation. It allows for a continuous optimization without interfering with usual beamtime for experiments by utilizing the 6s off-time in between injections into the stretcher ring. In a simulation using the actual accelerator’s settings as starting parameters, transmission rates have been increased significantly. The methods and results with the accelerator hardware are presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

At the Electron Stretcher Facility ELSA in Bonn the first acceleration stage consists of a 3 GHz traveling wave linear accelerator. It was powered by a 25 MW pulsed high power klystron amplifier, which had been in use for the last thirty years. After a major failure and due to the lack of spare part availability the RF station was rebuilt. In addition to a new klystron including its high voltage tank, the new setup also consists of major upgrades of the infrastructure, the pulse forming network and the safety interlocks to satisfy the contemporary requirements. A new monitoring system consisting of multi-channel sampling ADCs allows for automatic pulse-by-pulse analysis of the klystron parameters and simultaneous evaluation of RF performance and stability. In this contribution we will present the new RF station setup, which has successfully been operating since the beginning of 2021 as well as the new monitoring capabilities., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The 1.6 GeV booster synchrotron of the ELSA facility at the University of Bonn uses a DESY-type RF resonator which has been driven by a conventional klystron amplifier since its early days in 1967. The setup was modified to serve the ELSA stretcher ring as booster synchrotron in 1987, but the RF infrastructure was barely altered. As repairs of the reliable, but antiquated RF source became foreseeingly impossible due to the lack of spare part availability, the replacement of the klystron amplifier chain in favour of a state-of-the-art solid state amplifier was carried out. We describe the replacement and the operation experience with the new RF power amplifier., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The ELSA facility utilizes several digital cameras for beam profile measurements on luminous screens and synchrotron radiation monitors. Currently a multitude of devices with analog signal output are being replaced in favor of digital outputs, preferably with data transfer via Ethernet. The increased network traffic for streaming, analyzing, and distribution of processed data to control system and machine operators is managed through a supplementary camera network in which distributed computing is performed by the RabbitMQ message broker. This allows performant and platform-independent image acquisition from multiple cameras, real time profile analysis, and supports programming interfaces for C++ and Python. The setup and performance of the implementation are presented., Proceedings of the 11th International Beam Instrumentation Conference, IBIC2022, Kraków, Poland

The electron accelerator facility ELSA at the University of Bonn, Germany, can accelerate and store electrons with a final energy from 0.8GeV up to 3.2GeV. To routinely determine the filling pattern in the storage ring, a new measuring system has been developed. For hadron physics experiments the filling pattern, which is influenced by the injection from the pre-accelerating synchrotron, should be as homogeneous as possible. The new measurement system should provide a real-time measurement of the filling pattern, so that the injection can be continuously optimized. Moreover, a position measurement for each individual bunch is provided, from which the two transverse and the longitudinal tunes can be deduced. To measure the bunch-by-bunch intensity and position, the signals of the existing button-type BPMs will be digitized by fast 12-bit ADCs synchronized to the 500MHz ELSA radio frequency. The fast pre-processing and intermediate storage of the data is realized with a 500MHz clocked FPGA and transfers the data to a PC for further processing. First results of measurement system developed in-house will be presented., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand