The low solar atmosphere is composed of mostly neutral particles, but the importance magnetic field for understanding observed dynamics means that interactions between charged and particles play a very important role in controlling macroscopic fluid motions. As exchange momentum fluids, essential to effectively feel Lorentz force, through collisional interactions, relative timescale these dynam...

We report here the operation of a UV pre-ionised mini-TEA CO2 laser where the use of an external switch has been dispensed with. This was rendered possible by making the preioniser spark array play a dual role- that of a switch as well as of a source of UV photons that pre-conditioned the inter-electrode volume.

Former experiments on molten FeCl3 have shown that, as for A1C13, melting is accompanied by a transition from sixfold to essentially fourfold coordination. However, in contrast to AICI3, the FeCl3 melt near freezing has an appreciable ionic conductivity. We propose a model for the structure of FeCl3 melt as consisting of closely packed Fe2Cl6 bitetrahedral molecules in equilibrium with (Fe2Cl5)...

We propose use of the thickness of the ionisation front as a discriminant between alternative modes of reionisation in the early universe, by stars or by miniquasars. This will enable LOFAR to play an important role since the expected angular resolution is sensitive to scales that correspond to the transition between ionised and neutral regions for hard sources of ionising photons.