Lamb-shift and electric field measurements in plasmas

作者:Doveil F*; Cherigier Kovacic L; Strom P
来源:Plasma Physics and Controlled Fusion, 2017, 59(1): 014020.
DOI:10.1088/0741-3335/59/1/014020

摘要

The electric field is a quantity of particular relevance in plasma physics. Indeed, its fluctuations are responsible for different macroscopic phenomena such as anomalous transport in fusion plasmas. Answering a long-standing challenge, we offer a new method to locally and non-intrusively measure weak electric fields and their fluctuations in plasmas, by means of a beam of hydrogen ions or atoms. We present measurements of the electric field in vacuum and in a plasma where Debye shielding is measured. For the first time, we have used the Lamb-shift resonance to measure oscillating electric fields around 1 GHz and observed the strong enhancement of the Lyman-alpha signal. The measurement is both direct and non-intrusive. This method provides sensitivity (mV cm(-1)) and temporal resolution (ns) that are three orders higher compared to current diagnostics. It thus allows measuring fluctuations of the electric field at scales not previously reached experimentally.

  • 出版日期2017-1