CVD diamond detectors for fast VUV and SX-ray diagnostics on FTU

Bombarda, F.; Angelone, M.; Apruzzese, G.; Centioli, C.; Cesaroni, S; Gabellieri, L.; Grosso, Andrea; Marinelli, M.; Palomba, S.; Piergotti, V.; Pucella, G.; Rocchi, G.; Романо, А.; Sibio, A.; Tilia, B.; Verona, C.; Verona-Rinati, G.

doi:10.1088/1741-4326/ac233a

Cited by 4 publications

(3 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The developed methodology allows assessing which ELM is triggered by a pellet as well as which pellet actually triggered an ELM; the triggering efficiency in terms of percentage of triggered ELMs and in terms of triggering pellets as well as the triggering time delay and its distribution. The work has also shown how a relatively new type of diagnostic [34], based on a synthetic diamond sensor can be used to infer dynamical quantities related to ELMs. The resolution of such diagnostic allows in fact to derive a sharper triggered time distribution w.r.t the Be line signal that is used on a routine basis.…”

Section: Overview Of the Issuementioning

confidence: 99%

New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing

2023

View full text Add to dashboard Cite

The construction and operation of the first generation of magnetically controlled nuclear fusion power plants require the development of proper physics and the engineering bases. The analysis of data, recently collected by the actual largest and most important tokamak in the world JET, that has successfully completed his second deuterium and tritium campaign in 2021 (DTE2) with a full ITER like wall main chamber, has provided an important consolidation of the ITER physics basis. Thermonuclear plasmas are highly nonlinear systems characterized by the need of numerous diagnostics to measure physical quantities to guide, through proper control schemes, external actuators. Both modelling and machine learning approaches are required to maximize the physical understanding of plasma dynamics and at the same time, engineering challenges have to be faced. Fusion experiments are indeed extremely hostile environments for plasma facing materials (PFM) and plasma-facing components (PFC), both in terms of neutron, thermal loads and mechanical stresses that the components have to face during either steady operation or off-normal events. Efforts are therefore spent by the community to reach the ultimate goal ahead: turning on the first nuclear fusion power plant, DEMO, by 2050. This editorial is dedicated at reviewing some aspects touched in recent studies developed in this dynamic, challenging project, collected by the special issue titled “New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing”.

show abstract

Section: Overview Of the Issuementioning

confidence: 99%

New Challenges in Nuclear Fusion Reactors: From Data Analysis to Materials and Manufacturing

2023

View full text Add to dashboard Cite

show abstract

“…In such a harsh environment, most of the diagnostics used in present reactors will not be able to operate; therefore, alternatives must be found. Diamond-based detectors are one possibility, both because of their endurance to high neutron fluxes and their broadband responsivity [30,31]. Since 2007, two diamond detectors for VUV and Soft X-ray measurements have been installed at JET [30] to investigate their potentialities, and more recently on the FTU machine [31,32].…”

Section: Diagnosticsmentioning

confidence: 99%

“…Diamond-based detectors are one possibility, both because of their endurance to high neutron fluxes and their broadband responsivity [30,31]. Since 2007, two diamond detectors for VUV and Soft X-ray measurements have been installed at JET [30] to investigate their potentialities, and more recently on the FTU machine [31,32]. This is the reason why in the following, data collected by the UV diamond detector are shown for the first time in comparison with data from the spectroscopic cameras at JET measuring the ELM fingerprints in Be II emission line.…”

Section: Diagnosticsmentioning

confidence: 99%

An Unsupervised Spectrogram Cross-Correlation Method to Assess ELM Triggering Efficiency by Pellets

et al. 2022

View full text Add to dashboard Cite

The high confinement mode (H-mode) is considered the optimal regime for the production of energy through nuclear fusion for industrial purposes since it allows to increase the energy confinement time of the plasma roughly by a factor of two. Consequently, it has been selected at the moment as the standard scenario for the next generation of devices, such as ITER. However, pressure-driven edge instabilities, known as edge localized modes (ELMs), are a distinct feature of this plasma regime. Their extrapolated thermal and particle peak loads on the plasma-facing components (PFC) of the next generation of devices are expected to be so high as to damage such structures, compromising the normal operations of the reactors themselves. Consequently, the induced loads have to be controlled; this can be achieved by mitigating ELMs. A possibility then lays in increasing the ELMs frequency to lower the loads on the PFCs. As already demonstrated at JET, the pellet pacing of ELMs is considered one of the most promising techniques for such scope, and its optimization is therefore of great interest for present and future operations of nuclear fusion facilities. In this work, we suggest a method to access primary pieces of information to perform statistics, assess and characterize the pacing efficiency. The method, tested on JET data, is based on the clustering (k-means) of convoluted signals, using so-called spectrogram cross-correlation, between the measured pellets and ELMs time traces. Results have also been obtained by taking advantage of a new type of diagnostic for measuring the ELMs dynamic, based on synthetic diamond sensors, faster than the standard spectroscopic cameras used at JET.

show abstract