The BCS Critical Temperature at High Density

We investigate the BCS critical temperature $$T_c$$ T c in the high-density limit and derive an asymptotic formula, which strongly depends on the behavior of the interaction potential V on the Fermi-surface. Our results include a rigorous confirmation for the behavior of $$T_c$$ T c at high densities proposed by Langmann et al. (Phys Rev Lett 122:157001, 2019) and identify precise conditions under which superconducting domes arise in BCS theory.

Plasma-wall self-organization in magnetic fusion

This paper introduces the concept of plasma-wall self-organization (PWSO) in magnetic fusion. The basic idea is the existence of a time delay in the feedback loop relating radiation and impurity production on divertor plates. Both a zero and a onedimensional description of PWSO are provided. They lead to an iterative equation whose equilibrium fixed point is unstable above some threshold. This threshold corresponds to a radiative density limit, which can be reached for a ratio of total radiated power to total input power as low as 1/2. When detachment develops and physical sputtering dominates, this limit is progressively pushed to very high values if the radiation of non-plate impurities stays low. Therefore, PWSO comes with two basins for this organization: the usual one with a density limit, and a new one with density freedom, in particular for machines using high-Z materials. Two basins of attraction of PWSO are shown to exist for the tokamak during start-up, with a high density one leading to this freedom. This basin might be reached by a proper tailoring of ECRH assisted ohmic start-up in present middle-size tokamaks, mimicking present stellarator start-up. In view of the impressive tokamak DEMO wall load challenge, it is worth considering and checking this possibility, which comes with that of more margins for ITER and of smaller reactors.

Informing the informal: visualizing laneway housing and increased density in Toronto

Toronto is growing and attracting new population. Given that housing is a basic human need, Toronto’s population growth indicates a rising demand for housing. Meanwhile, spatial polarization of income is increasing in the city. Using Hulchanski’s illuminating study outlining those low and middle income households initially lived in the core of the city, near to transit networks and currently they cannot due to the high costs of housing this research investigates the physical and spatial capacity of a Toronto neighbourhood to increase affordable housing close to public transit while maintaining the physical character of the neighbourhood. As a means to address this affordable housing crisis laneway and informal housing is studied and the impact of these on the urban fabric, morphology, of neighbourhoods is studied. This research paper utilizes a mixed methods approach using semi-structured interviews, field research, spatial analysis and mapping, and the development of scenarios to test laneway and informal housing paradigms. This research concludes that: 1) informal housing and laneway housing can increase density while maintaining the physical character of a neighbourhood, 2) Toronto has an under-utilized laneway system that is a missed opportunity to increase density, 3) The current density limit for stable neighbourhoods defined by Toronto’s Zoning By-law is not realistic and there is a potential for increasing density limit while retaining the integrity of neighbourhood character, 4) Four to six storey laneway developments can create a new distinct character in laneways without changing street character.

Informing the informal: visualizing laneway housing and increased density in Toronto

Toronto is growing and attracting new population. Given that housing is a basic human need, Toronto’s population growth indicates a rising demand for housing. Meanwhile, spatial polarization of income is increasing in the city. Using Hulchanski’s illuminating study outlining those low and middle income households initially lived in the core of the city, near to transit networks and currently they cannot due to the high costs of housing this research investigates the physical and spatial capacity of a Toronto neighbourhood to increase affordable housing close to public transit while maintaining the physical character of the neighbourhood. As a means to address this affordable housing crisis laneway and informal housing is studied and the impact of these on the urban fabric, morphology, of neighbourhoods is studied. This research paper utilizes a mixed methods approach using semi-structured interviews, field research, spatial analysis and mapping, and the development of scenarios to test laneway and informal housing paradigms. This research concludes that: 1) informal housing and laneway housing can increase density while maintaining the physical character of a neighbourhood, 2) Toronto has an under-utilized laneway system that is a missed opportunity to increase density, 3) The current density limit for stable neighbourhoods defined by Toronto’s Zoning By-law is not realistic and there is a potential for increasing density limit while retaining the integrity of neighbourhood character, 4) Four to six storey laneway developments can create a new distinct character in laneways without changing street character.