TU Darmstadt / ULB / TUbiblio

Laser-Based High-Voltage Metrology with ppm Accuracy

König, Kristian Lars (2019):
Laser-Based High-Voltage Metrology with ppm Accuracy.
Darmstadt, Technische Universität, [Online-Edition: https://tuprints.ulb.tu-darmstadt.de/8401],
[Ph.D. Thesis]

Abstract

A beamline for high-precision collinear laser spectroscopy was designed, constructed and commissioned within this work. The main aspect was the development of a technique for a precise high-voltage determination with an accuracy in the sub-ppm regime. It is based on the laser-spectroscopic measurement of an ion velocity after acceleration with the high-voltage of interest by the determination of the Doppler shifted transition frequency. With an accurate knowledge of the rest-frame transition frequency and the mass, the high-voltage of interest can be traced back on natural constants like the speed of light and the elementary charge as well as on the measurement of a laser frequency. Since the laser frequency can be accurately determined with a frequency comb, this technique fulfills the requirements for the definition of a quantum standard. In first measurements with Ca⁺ and In⁺ ions, accuracies in the determination of high voltages between 1 kV and 20 kV of the order of 5 ppm were demonstrated. This corresponds to an increase in precision by a factor of 20 compared to earlier attempts and is mainly achieved by the improved experimental setup and the newly developed two-chamber approach with reference measurements. Further improvements of the laser stabilization scheme and of the laser-ion beam superposition that have been realized within this work, have the potential to enable laser-based high-voltage evaluations with uncertainties below 1 ppm. This would outperform the conventional technique based on high-voltage dividers and yield an unprecedented accuracy whereof several applications in metrology and science can benefit.

Item Type: Ph.D. Thesis
Erschienen: 2019
Creators: König, Kristian Lars
Title: Laser-Based High-Voltage Metrology with ppm Accuracy
Language: English
Abstract:

A beamline for high-precision collinear laser spectroscopy was designed, constructed and commissioned within this work. The main aspect was the development of a technique for a precise high-voltage determination with an accuracy in the sub-ppm regime. It is based on the laser-spectroscopic measurement of an ion velocity after acceleration with the high-voltage of interest by the determination of the Doppler shifted transition frequency. With an accurate knowledge of the rest-frame transition frequency and the mass, the high-voltage of interest can be traced back on natural constants like the speed of light and the elementary charge as well as on the measurement of a laser frequency. Since the laser frequency can be accurately determined with a frequency comb, this technique fulfills the requirements for the definition of a quantum standard. In first measurements with Ca⁺ and In⁺ ions, accuracies in the determination of high voltages between 1 kV and 20 kV of the order of 5 ppm were demonstrated. This corresponds to an increase in precision by a factor of 20 compared to earlier attempts and is mainly achieved by the improved experimental setup and the newly developed two-chamber approach with reference measurements. Further improvements of the laser stabilization scheme and of the laser-ion beam superposition that have been realized within this work, have the potential to enable laser-based high-voltage evaluations with uncertainties below 1 ppm. This would outperform the conventional technique based on high-voltage dividers and yield an unprecedented accuracy whereof several applications in metrology and science can benefit.

Place of Publication: Darmstadt
Divisions: 05 Department of Physics
05 Department of Physics > Institute of Nuclear Physics
05 Department of Physics > Institute of Nuclear Physics > Experimentelle Kernphysik
05 Department of Physics > Institute of Nuclear Physics > Experimentelle Kernphysik > Atom- und Kernphysik radioaktiver Nuklide
Date Deposited: 24 Feb 2019 20:55
Official URL: https://tuprints.ulb.tu-darmstadt.de/8401
URN: urn:nbn:de:tuda-tuprints-84014
Referees: Nörtershäuser, Prof. Dr. Wilfried and Kröll, Prof. Dr. Thorsten
Refereed / Verteidigung / mdl. Prüfung: 10 December 2018
Alternative Abstract:
Alternative abstract Language
Die kollineare Laserspektroskopie bietet neben vielfältigen wissenschaftlichen Anwendungen die Möglichkeit eine Spannungsmessung auf eine Frequenzmessung dopplerverschobener Spektrallinien zurückzuführen und eignet sich somit zur Definition des fehlenden Quantenstandards in der Hochspannungsmetrologie. Mit diesem Ziel wurde im Rahmen dieser Arbeit ein experimenteller Aufbau für hochpräzise, kollineare Laserspektroskopie entworfen, aufgebaut und in Betrieb genommen. Die mit der zu messenden Hochspannung beschleunigten Ionen erfahren bei der Wechselwirkung mit dem Spektroskopielaser eine geschwindigkeitsabhängige Dopplerverschiebung. Die resonante Laserfrequenz kann dank der Frequenzkammtechnologie mit hoher Genauigkeit bestimmt werden, sodass die über Naturkonstanten verknüpfte, anliegende Spannung akkurat ermittelt werden kann. Da sich die Masse der Ionen und deren Übergangsfrequenz im Ruhesystem in Fallenexperimenten präzise bestimmen lässt und die Ladung sowie die Lichtgeschwindigkeit bekannt sind, eignet sich dieser Ansatz zur Definition eines Quantenstandards. Erste laserspektroskopische Hochspannungsmessungen zwischen 1 kV und 20 kV mit Ca⁺ und In⁺ Ionen konnten mit resultierenden Unsicherheiten von etwa 5 ppm durchgeführt werden. Dies entspricht einer Genauigkeitssteigerung um einen Faktor 20 gegenüber bisherigen Versuchen. Insbesondere der verbesserte experimentelle Aufbau und ein neu entwickelter Ansatz, der auf einem Zwei-Kammer Prinzip mit Referenzmessungen basiert, trugen zu den Verbesserungen bei. Seit den ersten Messungen wurden weitere Entwicklungen in der Stabilisierung der Lasersysteme sowie in der Überlagerung von Laser- und Ionenstrahl verwirklicht, sodass in Zukunft Hochspannungsmessungen mit Unsicherheiten unter 1 ppm möglich sein sollten. Diese Genauigkeit würde das Limit der konventionellen, auf Spannungsteilern basierten Technik durchbrechen und so neue Möglichkeiten für präzise Anwendungen in Metrologie und Wissenschaft bieten.German
Export:

Optionen (nur für Redakteure)

View Item View Item