24th International Workshop on ECR Ion Sources (ECRIS'20)

Imaging in X-ray Ranges to Locally Investigate the Effect of the Two- Close-Frequency Heating in ECRIS Plasmas

28 Sept 2020, 13:35

25m

Oral

Speaker

Richard Racz (Atomki, Debrecen)

Description

Plasma instabilities limit the ECR Ion Sources
performances in terms of flux of the extracted highly
charged ions by causing beam ripple and unstable
operation conditions. In a 14 GHz ECRIS (Atomki,
Debrecen), the effect on the plasma instabilities in an
Argon plasma at Two Close Frequencies heating
scheme (the frequency gap is smaller than 1 GHz)
has been explored. A special multi-diagnostic setup
[1, 2] has been designed and implemented consisting
of detectors for the simultaneous collection of plasma
radio-self-emission and of high spatial resolution
X-ray images in the 500 eV - 20 keV energy domain
(using an X-ray pin-hole camera setup). We present
the comparison of plasma structural changes as
observed from X-ray images in single and doublefrequency
operations. The latter has been particularly
correlated to the confinement and velocity
anisotropy, also by considering results coming from
numerical simulations.