FAIR-GSI PhD Award 2019 for Kristian König


Dr. Kristian König has been honored with the FAIR-GSI PhD Award 2019. The annual award is endowed with 1,000 euros by Pfeiffer Vacuum. The award was presented recently by Professor Karlheinz Langanke, Research Director of FAIR and GSI, and Daniel Sälzer, Managing Director of Pfeiffer Vacuum GmbH, in the framework of the GSI-FAIR Colloquium. 

The research work for his thesis "Laser-Based High-Voltage Metrology with ppm Accuracy" was carried out by Kristian König in the research group of Professor Wilfried Nörtershäuser at the Technical University Darmstadt. The precise measurement of high voltages of several 10,000 volts is necessary in many areas of technology. Precision experiments in physics sometimes require accuracies down to one millionth of the measured voltage (1 ppm = 1 part per million). Kristian König has succeeded in measuring such voltages with the aid of a laser. He achieved this by accelerating ions (positively charged atoms) with the voltage to be measured and then measuring the influence of velocity on the "color" (frequency) of the light emitted by the ions. This method makes use of the Doppler effect which is known from daily life: If an ambulance with a siren approaches the observer at high speed, he hears a much higher tone than if the car were stationary. If the ambulance moves away, the sound becomes lower. If the pitch (frequency) is measured and the pitch of the resting siren is known, the speed of the ambulance can be calculated. Exactly the same happens with the light that atoms or ions emit in flight. This optical Doppler effect can be determined with extreme precision using lasers if the properties of the ion beam and the laser beam are controlled extremely well. Kristian König has constructed a setup enabling him to measure voltages to an accuracy of 5 ppm using this method. This accuracy is 20 times higher than what had been reached ever before with this technique. Such precise measurements are needed, for example, to determine the velocity of ions in the storage rings at GSI and at the future FAIR facility, and thus are crucial for a variety of precision experiments.

Pfeiffer Vacuum and GSI have a long-standing partnership. Vacuum solutions from Pfeiffer Vacuum have been used successfully in experimental setups at GSI for decades.

The annual FAIR-GSI PhD Award honors the best doctoral dissertation completed during the previous year. Eligible for nominations are dissertations that were financially supported by GSI as part of its strategic partnerships with the universities of Darmstadt, Frankfurt, Giessen, Heidelberg, Jena, and Mainz, or through the research and development program. In the framework of the Graduate School HGS-HIRe (Helmholtz Graduate School for Hadron and Ion Research), more than 300 PhD students currently perform research for their doctoral dissertations on topics closely related to GSI and FAIR. (CP)