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A superconducting radio-frequency (SRF) photo injector is in operation at the electron linac for beams with high brilliance and low emittance (ELBE) radiation center and generates continuous wave (CW) electron beams with high average current and high brightness for user operation since 2018. The speed of emittance measurement at the SRF gun beamline can be increased by improving the slit-scan system, thus the measurement time for one phase space mapping can be shortened from about 15 minutes to 90 seconds. A parallel algorithm and machine learning have been used to reduce the beamlet image noise. In order to estimate the uncertainty in the calculation of normalized emittance, we analyze the main error contributions such as slit position uncertainty, image noise, space charge effects and energy measurement inaccuracy.

At the ELBE Center for High-Power Radiation Sources, electrons are accelerated to an energy of up to 40 MeV in a superconducting linear accelerator that is operated in continuous wave (CW) mode. The acceleration is achieved using superconducting radio frequency (RF) cavities, which are driven by an analog low-level RF (aLLRF) system and solid-state-based RF amplifiers. The analog aLLRF system was transformed to a digital system based on the MicroTCA standard. It is in user operation since 2020. Here, the new digital system and its integration in the ELBE control system are described. Furthermore, the system is characterized by noise measurements and shows rms field stability of the digital LLRF (dLLRF) system of 0.01° in phase and 0.005% in amplitude. In addition, an algorithm for compensating long-term drifts is presented and characterized.

At the electron linac for beams with high brilliance and low emittance (ELBE) center for high-power radiation sources, the second version of a superconducting radio-frequency (SRF) photoinjector has been put into operation and has been routinely applied for user operation at the ELBE electron accelerator. SRF guns are suitable for generating a continuous wave electron beam with high average currents and high beam brightness. The SRF gun at ELBE has the goal to generate short electron pulses with bunch charges of 200–300 pC at typical repetition rates of 100 kHz for the production of superradiant, coherent terahertz radiation. The SRF gun includes a 3.5-cell, 1.3-GHz niobium cavity and a superconducting solenoid. A support system with liquid nitrogen (LN_{2}) cooling allows the operation of normal-conducting, high quantum efficiency photocathodes. We present the design and performance of the SRF gun as well as beam measurement results of the operation with Mg photocathodes at an acceleration gradient of 8 MV/m (4 MeV kinetic energy). In the last section, we discuss the SRF gun application for production of coherent terahertz radiation at the ELBE facility.

The advance of efficient hydrogen-air combustion systems has increasingly become of interest in the framework of the development of fuel cell systems, especially for the automotive sector. Therefore, compact modulating systems are required, with the additional demand of low emissions, to be integrated in a fuel cell system. A modulating combustion system based on combustion within inert porous media and an integrated heat exchanger has been developed and investigated. The system is able to handle premixed combustion of lean H 2 /air mixtures at a surface load range of 1075 kW/m 2 –2150 kW/m 2 , and a global equivalence ratio of ϕ = 0.5 . The special hydrogen-air mixing concept eliminates the risk of flame flashback and enables operation with very low NO x emissions.

konnen anlagenspezifisch zu einem nichtlinearen dynamischen Simulationsmodell der Regelstrecke verknupft werden. Das Konzept der Modellierung nach dem Baukastenprinzip bietet einerseits die Moglichkeit zur Anlagensimulation, z. B. zum Tuning klassischer Regelungskonzepte. Andererseits bildet das linearisierte generische Zustandsraummodell die Grundlage eines MPCAlgorithmus, der speziell auf die Bedurfnisse wechselnder Betriebsarten angepasst wurde.