11 research outputs found

    Newly uncovered physics of MHD instabilities using 2-D electron cyclotron emission imaging system in toroidal plasmas

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    Validation of physics models using the newly uncovered physics with a 2-D electron cyclotron emission imaging (ECEi) system for magnetic fusion plasmas has either enhanced the confidence or substantially improved the modeling capability. The discarded "full reconnection model" in sawtooth instability is vindicated and established that symmetry and magnetic shear of the 1/1 kink mode are critical parameters in sawtooth instability. For the 2/1 instability, it is demonstrated that the 2-D data can determine critical physics parameters with a high confidence and the measured anisotropic distribution of the turbulence and its flow in presence of the 2/1 island is validated by the modelled potential and gyro-kinetic calculation. The validation process of the measured reversed-shear Alfveneigenmode (RSAE) structures has improved deficiencies of prior models. The 2-D images of internal structure of the ELMs and turbulence induced by the resonant magnetic perturbation (RMP) have provided an opportunity to establish firm physics basis of the ELM instability and role of RMPs. The importance of symmetry in determining the reconnection time scale and role of magnetic shear of the 1/1 kink mode in sawtooth instability may be relevant to the underlying physics of the violent kink instability of the filament ropes in a solar flare

    Ageism in the third age

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    In the developed world, later life has brought more opportunities to contribute to society and pursue personal goals outside the role of paid work, combined with less stigma and greater recognition of the worth of older people. These values do not necessarily extend to the “oldest old” where some people in the fourth age (people 80 years old and over) continue to face increasing stigma and societal stereotypes from those in the third age (people 60–79 years old). Ageism between these two cohorts is rarely discussed in the literature. Potential ageism involves stereotypical perceptions of the oldest old and may prove detrimental to those transitioning from the third to the fourth age if a resultant resistance to maintain their engagement and independence into older age occurs. This chapter explores the subtleties of these inter-cohort ageist discourses particularly from a health and social care perspective and considers the implications for transitions of older people between the third and fourth age. It addresses the challenges and adjustments needed to ensure continuing and inclusive engagement in society, in order to support independence to grow old without the fear of discrimination

    Diagnostics for plasma control on DEMO : challenges of implementation

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    As a test fusion power plant, DEMO will have to demonstrate reliability and very long pulse/steady-state operation, which calls for unprecedented robustness and reliability of all diagnostic systems (also requiring adequate redundancy). But DEMO will have higher levels of neutron and gamma fluxes, and fluences, nuclear heating, and fluxes of particles than ITER, and probably reduced physical access. In particular, the neutron fluence will be about 15–50 times higher than that in ITER. As a consequence, some diagnostics that will work in ITER are likely to be unfeasible in DEMO. It is important, therefore, to develop a new way of thinking with respect to that employed to date in which diagnostics are added after the machine has been basically designed: if certain diagnostics are deemed essential for the control of DEMO, they will have to be taken into account during the entire design phase

    Corrigendum to “Technology Roadmapping for mission-led agile hardware development: a case study of a commercial fusion energy start-up” Technological Forecasting & Social Change 158 (2020) 120064 (Technological Forecasting & Social Change (2020) 158, (S0040162519318281), (10.1016/j.techfore.2020.120064))

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    Inadvertently the authors omitted information in the caption of Figure 6, which should read: “Compact tokamak concept based on a collaboration between PPPL and Tokamak Energy (original image created by T. Brown of Princeton Plasma Physics Laboratory)”.The authors apologise for this omission. The updated email address of the first author is [email protected]
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