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Electron cyclotron heating (ECH) is one of the most common methods used for heating stellarator plasmas, providing both ionization for startup and net-current free heating during the discharge. This paper presents the design of the ECH heating system for the Stellarator of Costa Rica (SCR-1), a small modular stellarator under construction at the Instituto Tecnologico de Costa Rica (ITCR). The SCR-1 is a small (Major radius 0.238 m, mean plasma radius 0.042 m) low budget device, using a 2 period magnetic field with flat rotational transform profile (i=0.3), a resonant strength of 8.78×10−2 T and expected to achieve a 15 eV temperature with an electron line density of 3.74×1015 m−3.

This paper describes briefly the design and construction of a small modular stellarator for magnetic confinement of plasma, called Stellarator of Costa Rica 1, or SCR-1; developed by the Plasma Physics Group of the Instituto Tecnologico de Costa Rica, PlasmaTEC. The SCR-1 is based on the small Spanish stellarator UST_1, created by the engineer Vicente Queral. The SCR-1 will employ stainless steel torus-shaped vacuum vessel with a major radius of 460.33 mm and a cross section radius of 110.25mm. A typical SCR-1 plasma will have an average radius 42.2 mm and a volume of 8 liters (0.01 m3), and an aspect ratio of 5.7. The magnetic resonant field will be 0.0878 T, and a period of 2 (m=2) with a rotational transform of 0.3. The magnetic field will be provided by 12 modular coils, with 8 turns each, with an electrical current of 8704 A per coil (1088 A per turn of each coil). This current will be fed by a bank of cell batteries. The plasma will be heated by ECRH with magnetrons of a total power of 5kW, in the first harmonic at 2.45GHz. The expected electron temperature and density are 15 eV and 1017 m−3 respectively with an estimated confinement time of 7.30 x 10−4 ms. The initial diagnostics on the SCR-1 will consist of a Langmuir probe, a heterodyne microwave interferometer, and a field mapping system. The first plasma of the SCR-1 is expected at the end of 2011.

Bioassay-guided investigation of the ethanol extract of Peperomia galioides using a tensile strength method in mice as a monitor led to the isolation of epi-alpha-bisabolol (1) (ED(50) 155 microg/mL). An in vivo healing study of selected commercially available monoterpenoids yielded two bioactive compounds, alpha-bisabolol (2) and alpha-terpineol (3) (ED(50) of 228 and 240 microg/g mouse[corrected], respectively).

This paper aims at briefly describing the design and construction issues of the stellarator of Costa Rica 1 (SCR-1). The SCR-1 is a small modular Stellarator for magnetic confinement of plasma developed by the Plasma Physics Group of the Instituto Tecnologico de Costa Rica (ITCR). The SCR-1 is based on the small Spanish Stellarator UST_1 (Ultra Small Torus 1), created by Eng. Vicente Queral. These mains issues consist of the size of the Stellarator, closeness between coils, coupling of ECH to the vacuum chamber and the device for support. The size has become a problem because the vacuum chamber does not allow a lot of space to attach diagnosis devices, the heating system, the vacuum system and the very same support of the chamber. As a result of this lack of space, the Stellarator's coils are placed very close to each other; this means that two of the coils around of the vacuum chamber clash and cannot be placed as designed. The issue regarding the coupling of the ECH (electron cyclotron radio-frequency) to the vacuum chamber comprises the fact that the wave guide with rectangular shape does not match the CF port with circular shape on the vacuum chamber. In addition, the device for supporting the Stellarator has presented a challenge because of its size and the placement of the coils; in other words, there is not enough space between the ports and coils in the Stellarator to place appropriately the device for support.