UST_2 is a small modular three period quasi-isodynamic stellarator of major radius 0.29 m and plasma volume 10 litres being currently built to by additive manufacturing (3D printing).

Five main engineering concepts are researched and developed: i) additive manufacturing combined with casting, consisting of an additively manufactured light truss structure enclosed within a thin external surface, where the internal volume is filled with a material that solidifies or cures after filling, ii) coil frame, fabricated following the previous concept, that includes grooves in the external surface in which conductors are wound, and iii) a single conductor pancake compressed and embedded in each groove, iv) a modular splittable vacuum vessel composed of 6 identical sectors fabricated as a copper liner that is externally reinforced by cast epoxy resin, v) the device can be divided in six identical modules for easy, fast and cheap maintenance and upgrade. Read more (link to .pdf, my PhD thesis).

Concept of separation of sectors

A Last Closed Flux Surface (the external surface of the plasma) that includes a straight non-torsion plasma section was calculated for UST_2. For that, a three-period quasi-isodynamic magnetic configuration from German researchers was modified so as to allow possible enhanced engineering and maintenance features such as large planar tilting coils and detachable sectors. However, confinement was slighly deteriorated. Read more (link to .pdf, my PhD thesis)

See more photos in Upgrades and Gallery in the link of the crowdfunding campaing for the construction of UST_2

http://igg.me/at/VyingFusion

Poincare plot (cut of magnetic surfaces of the plasma)

Venture Project proposal (pdf) [Will be upgraded]

The UST_3 development, planned to start at the end of 2015, is aimed at building a small but powerfull stellartor. UST_3 will be fabricated by the 3D-printing and construction methods developed for UST_2, and some other new techniques. It will contain thick copper coils to achieve high magnetic field and high plasma temperature and density, that is, high tripple product (high properties for so a small device). An ideal UST_3 should fulfil three aims: i) to be turbulence optimised to some extent (and also neoclassical) at high beta (10-15% beta limit), ii) to implement radical innovation for power extraction (external divertors) and iii) massive copper coils. International collaboration and funds are being sought for the endeveour.

Allure Ignition Stellarator reactor and strategy