Conceptual designs of fast-ion loss detectors for the TJ-II stellarator

Abstract

Articles you may be interested inAn instrumental and numerical method to determine the hydrogenic ratio in isotopic experiments in the TJ-II stellaratora) Rev. Sci. Instrum. 85, 11E405 (2014);A flexible luminescent probe to monitor fast ion losses at the edge of the TJ-II stellarator Rev. Sci. Instrum. 79, 093511 (2008);We present conceptual designs for two compact, flexible fast-ion loss detectors for quantifying the direct loss term, which is predicted by theoretical calculations to be the most relevant one, from TJ-II plasmas heated by Neutral Beam Injectors. In both conceptual designs, we attempt to encompass the need for a very sensitive system with no imaging capabilities and that for a less sensitive system with some imaging capacity. Finally, we model fast-ion losses from this device in order to identify the optimal locations for such detectors, while also taking experimental constrains into account, and we estimate the ion currents in these detectors as well as the resultant output signal levels.

The response of several luminescent materials to keV and MeV ions

“…This work is primarily motivated by the application of such radiation-hard luminescent materials in a diagnostic probe, based on the collection of light induced by ions impacting on a thin screen, for measuring fast ion losses, close to the edge of hot plasmas in the TJ-II stellarator [9,10]. In future operations modes, its plasmas will receive up to 2 MW of additional heating from two neutral beam injector (NBI) systems in which neutral hydrogen is accelerated to 40 keV [11] and from which theoretical studies predict that losses due to fast ions could reach 30% of the injected power [12].…”

A flexible luminescent probe to monitor fast ion losses at the edge of the TJ-II stellarator

“…The conceptual design, the toroidal and poloidal location of the detector, as well as the peculiarities and complicated geometry of TJ-II, were outlined in more detail in a previous publication. 13 Since then some geometrical modifications have been made to the detector head. See Fig.…”

The response of a radiation resistant ceramic scintillator (Al2O3:Cr) to low energy ions (–60keV)

“…4 A primary motivation is the development of a fast-ion-loss diagnostic probe for the TJ-II stellarator, 5 while the identification of suitable materials for such detectors in ITER gives this work further scope. 4 A primary motivation is the development of a fast-ion-loss diagnostic probe for the TJ-II stellarator, 5 while the identification of suitable materials for such detectors in ITER gives this work further scope.…”