Jesse Schelfhout

Abstract:

This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024 (Second Terrestrial Very-Long-Baseline Atom Interferometry Workshop, Imperial College, April 2024), building on the initial discussions during the inaugural workshop held at CERN in March 2023 (First Terrestrial Very-Long-Baseline Atom Interferometry Workshop, CERN, March 2023). Like the summary of the first workshop (Abend et al. in AVS Quantum Sci. 6:024701, 2024), this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions (Memorandum of Understanding for the Terrestrial Very Long Baseline Atom Interferometer Study).

Abstract:

A method to confine plasmas based on a new form of z-pinch was discovered and published in the late 1970s by two European physicists, Owen Storey and Laurent Cairó, building on a prior discovery by American astrophysicist Eugene Parker [1]. They proved that when supersonically flowing plasma is confined by a magnetic field parallel to the flow, there are circumstances in which a secondary magnetic field discovered by Parker emerges that reinforces the confinement, thereby reducing the requirement for the external magnetic field. The resulting overall confining field is concentrated in the thin static sheath-like boundary layer between the plasma and the external field, while the bulk plasma remains field-free and current-free. They suggested that this might be applicable to fusion and proposed a conceptual device exploiting this effect [2, 3]. The confinement in this device would be intrinsically MHD-stable, and more energetically efficient than that of most devices currently under investigation. Despite its promises, this method was not investigated further at the time and eventually faded from memories. Moreover, the effect discovered by Parker has not yet been observed in numerical simulation or experimentally, because it has never been sought. In collaboration with one of the original scientists, our independent research group is reviewing and continuing this work to bring it to a Technology Readiness Level of 3 [4]. This involves numerical simulations to observe the emergent effect and to characterise the proposed device concept, including its plasma confinement and stability characteristics, and means to maintain plasma density, temperature, and bulk flow velocity. In the success case, the proposed device has the potential to confine an isotropic plasma more efficiently and economically, with immunity to the major MHD instabilities, good accessibility due to a simple and modular design with high aspect ratio, and continuous operation. This short paper based on the poster presented at the 50th Conference of the European Plasma Society in Salamanca, Spain, in July 2024, aims to present briefly Parker’s Effect and how it can be used to confine a flowing plasma using a sheath pinch, how this possibility can be verified. We summarise recent work and present a high-level work plan. We are seeking collaborators for this venture.