Dan Kiselman

Service mode observations

Andreas Lagg

SUNRISE III

Ilaria Ermolli

IBIS

Carl Schaffer

GRIS Data Archive

A Leonard Python lecture & exercises

Mats Carlsson

Virtual Access Programme

Son test presentation link to project

In this contribution, we will present a simplified model for thermally driven dynamo developed using the shell technique. One result of the model is the enhancement of global heat transport before polarity reversals, indicating the critical role that heat transport can play in their occurrence. We have clarified this role by analysing a large set of numerical simulations of our dynamo model. In particular, convergent cross-mapping, a test assessing the presence and the strength of the causal connection between two variables in a nonlinear dynamical system, shows that an increase in the convective heat flux can cause the onset of polarity reversals. According to the idea of the critical role played by convective heat transport, the existing two branches of activity observed for low-mass, fast-rotating, fully convective stars may be explained in terms of the efficiency of global heat transport.

Piz Diant

The three-dimensional (3D) coronal magnetic field has not yet been directly observed. However, for a better understanding and prediction of magnetically-driven solar eruptions, 3D models of solar active regions are required. This work aims to provide insight into the significance of different 3D extrapolation models for flare prediction purposes, employing potential field (PF), linear force-free field (LFFF), nonlinear force-free field (NLFFF) models, and a neural network-based method integrating observational data and NLFFF physics. The 3D coronal magnetic field structure of a "flaring" (AR11166) and "flare-quiet" (AR12645) active region, in terms of their flare productivity, is constructed via the four extrapolation methods. To analyse the evolution of the field, six prediction parameters were employed throughout, from the photosphere up to the base of the lower corona.

S.V. Bulanov, ELI BEAMLINES, Dolni Brezany, Czech Republic

In a relativistic plasma regime magnetic reconnection may take completely different features due to the relativistic limit on the particle velocity under conditions of quasineutrality when the spatial variation of the magnetic field cannot be balanced by the electron current in Ampere's law. In this case the MHD description fails and the magnetic field dynamics is dominated by the displacement current and by the corresponding inductive electric field as proposed by S.I. Syrovatskii nearly 60 years ago in the context of Cosmic physics, and may provide an efficient, time variable acceleration mechanism in a relativistic inhomogeneous plasma. Recently this regime it has become of interest also in the context of relativistic laboratory plasmas .J. Gu, F. Pegoraro, P.V. Sasorov, D. Golovin, A. Yogo, G. Korn, S.V. Bulanov, {\it Electromagnetic Burst Generation during Annihilation of Magnetic Field in Relativistic Laser-Plasma Interaction}, Sci. Rep., 9 , 19462 (2019)

Bo Lindberg, Luc Rouppe van der Voort, Jaime de la Cruz Rodriguez

The development of instrumentation for the European Solar Telescope (EST) benefits strongly from on-going development and use of similar instrumentation on previously built European solar telescopes. Here, we discuss the design and performance of CRISP and CHROMIS, which are the most scientifically productive instruments at the Swedish 1-m Solar Telescope. These are of high relevance to the development of the Tunable Imager Spectrometers (TISs), which will be functionally similar to CRISP and are expected to be the most highly requested first-generation instruments at EST. We showcase sample data and demonstrate the superior image quality of CRISP and CHROMIS. We describe their compact design without folding mirrors, which delivers high transmission, ease of alignment, and relatively low design and construction cost. We finally demonstrate that a similar design most likely can be implemented at EST but refer to a separate presentation describing the details of such TIS designs.