Deconvolution-based correction of alkali beam emission spectroscopy density profile measurements

Pusztai, István; Pokol, Gergö; Dunai, D.; Réfy, D.; Por, G.; Anda, G.; Zoletnik, S.; Schweinzer, J.

doi:10.1063/1.3205930

Cited by 13 publications

(6 citation statements)

References 17 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…17 ). Anyhow, in the recent years, neutral alkali beams (namely Li and Na) with an energy of around 60 keV were used to diagnose the magnetically confined plasmas in the scrape-off layer and the edge, namely, to measure the plasma turbulence and density profile of the plasma electron 18 – 23 .…”

Section: Introductionmentioning

confidence: 99%

Total and differential ionization cross sections in collision between nitrogen atom and singly charged sodium ion

Al-Ajaleen,

Tőkési

2023

Sci Rep

View full text Add to dashboard Cite

We present a theoretical study of the ionization of nitrogen atom by a singly charged sodium ion using the classical trajectory Monte Carlo method. Although we suffer from a lack of cross section data of this collision system, the knowledge of the basic cross sections is essential in fusion science, because this reaction has potential applications in the diagnostic of magnetically confined fusion plasmas. In our investigations, the Na+–N collision system is reduced to a three-body problem. The interaction between the collision partners is described by the Garvey-type model potential. The results of our study provide insight into the dynamics of singly charged sodium–nitrogen interactions. The total cross sections are presented in the impact energy range between 10 keV and 10 MeV and compared them with the available experimental data. The single and double differential cross sections are presented at 30, 40, 50 and 60 keV energies related to the energies of the plasma diagnostic used in the nuclear fusion.

show abstract

Section: Introductionmentioning

confidence: 99%

Total and differential ionization cross sections in collision between nitrogen atom and singly charged sodium ion

Al-Ajaleen,

Tőkési

2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The routine measurements of electron density profiles from the Li-BES have been demonstrated on various fusion devices, e.g. ASDEX Upgrade [1], JET [2], TEXTOR [3,4], DIII-D [5], W7-AS [6] and LHD [7]. Its capability to measure density fluctuations has been well demonstrated in [8,9].…”

Section: Introductionmentioning

confidence: 99%

Characterization of the Li-BES at ASDEX Upgrade

Willensdorfer

Birkenmeier

Fischer

et al. 2014

Plasma Phys. Control. Fusion

100

View full text Add to dashboard Cite

Abstract.The lithium beam emission spectroscopy (Li-BES) is a powerful diagnostic to resolve the plasma edge density with high temporal and spatial resolution. The recent upgrades of the Li-BES at ASDEX Upgrade and the resulting gain in photon flux allow the plasma edge density to be determined with an advanced level of accuracy. Furthermore, electron density fluctuations are measured using Li-BES. The Li-BES capabilities and limitations to measure electron density profiles as well as density fluctuations are presented. Li-BES is well suited to characterize electron density turbulence in the scrape off layer (SOL) with decreasing sensitivity towards the plasma core. This is demonstrated by simulations as well as by comparisons with other diagnostics. Li-BES is an appropriate tool to study transport phenomena in the SOL over a wide range of plasma parameters due to its robustness and routine usage.

show abstract

“…The code is written in Interactive Data Language (IDL) and utilizes the atomic physics core of the RENATE BES simulator. 30,31 The atomic physics of the beam can be discussed within the collisional-radiative model. The light profile and the density profile are connected through the rate equations which is a coupled differential equation system.…”

Section: Density Profile Reconstructionmentioning

confidence: 99%

Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system

Réfy

Brix

Gomes

et al. 2018

Review of Scientific Instruments

Self Cite

View full text Add to dashboard Cite

Diagnostic alkali atom (e.g., lithium) beams are routinely used to diagnose magnetically confined plasmas, namely, to measure the plasma electron density profile in the edge and the scrape off layer region. A light splitting optics system was installed into the observation system of the lithium beam emission spectroscopy diagnostic at the Joint European Torus (JET) tokamak, which allows simultaneous measurement of the beam light emission with a spectrometer and a fast avalanche photodiode (APD) camera. The spectrometer measurement allows density profile reconstruction with ∼10 ms time resolution, absolute position calculation from the Doppler shift, spectral background subtraction as well as relative intensity calibration of the channels for each discharge. The APD system is capable of measuring light intensities on the microsecond time scale. However ∼100 μs integration is needed to have an acceptable signal to noise ratio due to moderate light levels. Fast modulation of the beam up to 30 kHz is implemented which allows background subtraction on the 100 μs time scale. The measurement covers the 0.9 < ρ < 1.1 range with 6-10 mm optical resolution at the measurement location which translates to 3-5 mm radial resolution at the midplane due to flux expansion. An automated routine has been developed which performs the background subtraction, the relative calibration, and the comprehensive error calculation, runs a Bayesian density reconstruction code, and loads results to the JET database. The paper demonstrates the capability of the APD system by analyzing fast phenomena like pellet injection and edge localized modes.

show abstract

Deconvolution-based correction of alkali beam emission spectroscopy density profile measurements

Abstract: Characteristics and magnitude of the mentioned systematic error and its reduction by the introduced method are studied by means of the comprehensive alkali BES simulation code RENATE.

Cited by 13 publications

References 17 publications

Total and differential ionization cross sections in collision between nitrogen atom and singly charged sodium ion

Total and differential ionization cross sections in collision between nitrogen atom and singly charged sodium ion

Characterization of the Li-BES at ASDEX Upgrade

Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system

Contact Info

Product

Resources

About