Implementation of synthetic fast-ion loss detector and imaging heavy ion beam probe diagnostics in the 3D hybrid kinetic-MHD code MEGA

Oyola, P.; Gonzalez-Martin, J.; García-Muñoz, M.; Galdón-Quiroga, J.; Birkenmeier, G.; Viezzer, E.; Dominguez-Palacios, J.; Rueda-Rueda, J.; Rivero-Rodriguez, J. F.; Todo, Y.

doi:10.1063/5.0043757

Cited by 3 publications

(1 citation statement)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Synthetic loss detectors have been produced to compare numerically modeled losses to experimental measurements [14][15][16][17][18]. It has been readily observed that fast ion loss detector (FILD) signals correlate with many loss mechanisms of interest [19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Simulating energetic particle losses in JET plasmas with a reverse integration biasing scheme

Bonofiglo¹,

Podestà²,

White³

et al. 2022

Nucl. Fusion

View full text Add to dashboard Cite

An integrated energetic particle transport model has been constructed in JET plasmas constrained by experimental fast ion loss measurements. The model incorporates a synthetic fast ion loss detector identical to JET's thin-foil Faraday cup fast ion loss detector array. The loss model combines analyses from the TRANSP and ORBIT-kick codes with enhanced features for producing the synthetic diagnostic. Extensions to the ORBIT code framework allow a full-orbit representation within the vacuum region that can map particles directly to an installed detector geometry. Since synthetic fast ion loss detectors are plagued by weak loss statistics, a novel reverse integration biasing scheme has been implemented to boost computational efficiency. The model is validated against experimental loss measurements induced by long-lived kink modes and is found to be in good agreement. This confirms the development of a fully integrated transport/loss model which can be quantitatively verified against experiment allowing for future validation and predictive studies. The model is particularly useful for more complicated plasma scenarios that involve multiple fast ion species such as JET's 2021 DT-campaign.

show abstract

Section: Introductionmentioning

confidence: 99%

Simulating energetic particle losses in JET plasmas with a reverse integration biasing scheme

Bonofiglo¹,

Podestà²,

White³

et al. 2022

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

First measurements of an imaging heavy ion beam probe at the ASDEX Upgrade tokamak

Galdon-Quiroga,

Birkenmeier,

Oyola

et al. 2024

Review of Scientific Instruments

View full text Add to dashboard Cite

The imaging heavy ion beam probe (i-HIBP) diagnostic has been successfully commissioned at ASDEX Upgrade. The i-HIBP injects a primary neutral beam into the plasma, where it is ionized, leading to a fan of secondary (charged) beams. These are deflected by the magnetic field of the tokamak and collected by a scintillator detector, generating a strike-line light pattern that encodes information on the density, electrostatic potential, and magnetic field of the plasma edge. The first measurements have been made, demonstrating the proof-of-principle of this diagnostic technique. A primary beam of 85/87Rb has been used with energies ranging between 60 and 72 keV and extracted currents up to 1.5 mA. The first signals have been obtained in experiments covering a wide range of parameter spaces, with plasma currents (Ip) between 0.2 and 0.8 MA and on-axis toroidal magnetic field (Bt) between 1.9 and 2.7 T. Low densities appear to be critical for the performance of the diagnostic, as signals are typically observed only when the line integrated density is below 2.0–3.0 × 1019 m−2 in the central interferometer chord, depending on the plasma shape. The strike line moves as expected when Ip is ramped, indicating that current measurements are possible. Additionally, clear dynamics in the intensity of the strike line are often observed, which might be linked to changes in the edge profile structure. However, the signal-to-background ratio of the signals is hampered by stray light, and the image guide degradation is due to neutron irradiation. Finally, simulations have been carried out to investigate the sensitivity of the expected signals to plasma density and temperature. The results are in qualitative agreement with the experimental observations, suggesting that the diagnostic is almost insensitive to fluctuations in the temperature profile, while the signal level is highly determined by the density profile due to the beam attenuation.

show abstract

Validation of the synthetic model for the imaging heavy ion beam probe at the ASDEX Upgrade tokamak (invited)

Oyola,

Birkenmeier,

Lindl

et al. 2024

Review of Scientific Instruments

View full text Add to dashboard Cite

Recent experiments at the ASDEX Upgrade tokamak have provided the first ever measurements from the imaging heavy-ion beam probe. In this work, we show that the developed simulation framework can reproduce qualitatively the measurement’s observed shape and position. Quantitatively, we demonstrate that the model reproduces, within the experimental uncertainties, the observed signal levels. A detailed explanation of the synthetic model is presented, along with the calibration of the optical setup that reproduces the measurements.

show abstract

Implementation of synthetic fast-ion loss detector and imaging heavy ion beam probe diagnostics in the 3D hybrid kinetic-MHD code MEGA

Cited by 3 publications

References 28 publications

Simulating energetic particle losses in JET plasmas with a reverse integration biasing scheme

Simulating energetic particle losses in JET plasmas with a reverse integration biasing scheme

First measurements of an imaging heavy ion beam probe at the ASDEX Upgrade tokamak

Validation of the synthetic model for the imaging heavy ion beam probe at the ASDEX Upgrade tokamak (invited)

Contact Info

Product

Resources

About